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1. A pharmaceutical product comprising at least one therapeutic agent, whereby a unit dose of said therapeutic agent as provided by said pharmaceutical product can be administered to a patient during the passage of said therapeutic agent through the gastrointestinal tract of the patient, wherein said therapeutic agent is characterized as having an aqueous solubility of not greater than about 1 in 30 to 1 in 100, weight/volume, when measured at a temperature in the range of 15 to 25° C. 2. A pharmaceutical product according to claim 1, which further comprises a support material for the therapeutic agent. 3. A pharmaceutical product according to claim 2, wherein the support material is selected from the group consisting of lactose, silica, calcium carbonate and calcium phosphate. 4. A pharmaceutical product according to claim 2, wherein said support is reticulated. 5. A pharmaceutical product comprising at least one therapeutic agent in crystalline form, said pharmaceutical product comprising at least one reticulated three-dimensional microstructure comprising: a network of substantially interconnecting walls, said walls being provided by a multiplicity of crystals arranged to at least partially abut each other; and a multiplicity of pores defined by said substantially interconnecting walls. 6. A pharmaceutical product according to claim 5, wherein the walls of said reticulated microstructure have a thickness in the range of 0.01 to 40 μm. 7. A pharmaceutical product according to claim 5, wherein the pores of said reticulated microstructure have a pore size in the range of 0.01 to 60 μm. 8. A pharmaceutical product according to claim 5, comprising: a network of substantially interconnecting walls, wherein said walls are provided by a multiplicity of crystals arranged to at least partially abut each other substantially as hereinbefore described, and wherein substantially all of said walls have a thickness of less than about 0.5 μm; and a multiplicity of pores defined by said walls, wherein substantially all of said pores have a pore size in the range of 0.1 to 1 μm. 9. A pharmaceutical product according to claim 8, wherein substantially all of the walls have a thickness in the range of 0.01 to 0.5 μm. 10. A pharmaceutical product according to claim 9, wherein substantially all of the walls have a thickness of less than about 0.1 μm. 11. A pharmaceutical product according to claim 8, wherein substantially all of the pores have a pore size typically in the range of 0.3 to 0.6 μm. 12. A pharmaceutical product according to claim 11, wherein substantially all of the pores have a pore size of about 0.5 μm. 13. A pharmaceutical product according to claim 5, comprising a primary reticulated three-dimensional microstructure and a secondary reticulated three dimensional microstructure, wherein said secondary reticulated microstructure defines the walls of said primary reticulated microstructure, and wherein: said primary reticulated microstructure comprises: a network of substantially interconnecting primary walls, wherein said primary walls are provided by said secondary reticulated microstructure and substantially all of said primary walls have a thickness in the range of 10 to 40 μm; and a multiplicity of primary pores defined by said primary walls, wherein substantially all of said primary pores have a pore size in the range of 40 to 60 μm; and said secondary reticulated microstructure comprises: a network of substantially interconnecting secondary walls, wherein said secondary walls are 10 provided by a multiplicity of crystals arranged to at least partially abut each other, wherein substantially all of said secondary walls have a thickness in the range of 0.5 to 5 μm; and a multiplicity of secondary pores defined by said secondary walls, wherein substantially all of said secondary pores have a pore size in the range of 0.1 to 5 μm. 14. A pharmaceutical product according to claim 13, wherein substantially all of the primary walls have a thickness in the range of 20 to 30 μm. 15. A pharmaceutical product according to claim 13, wherein substantially all of the primary pores have a pore size in the range of 45 to 55 μm. 16. A pharmaceutical product according to claim 13, wherein substantially all of the secondary walls have a thickness in the range of 0.5 to 1.5 μm. 17. A pharmaceutical product according to claim 13, wherein substantially all of the secondary pores have a pore size in the range of 0.5 to 1 μm. 18. A pharmaceutical product according to claim 5, wherein the multiplicity of crystals defining the walls of said reticulated microstructure or microstructures consist essentially of crystals of a therapeutic agent. 19. A pharmaceutical product according to claim 18, comprising at least one reticulated three-dimensional microstructure comprising: a network of substantially interconnecting walls provided by a multiplicity of crystals arranged to at least partially abut each other, said crystals defining said walls consisting essentially of crystals of said therapeutic agent; and a multiplicity of pores defined by said substantially interconnecting walls. 20. A pharmaceutical product according to claim 5, said pharmaceutical product comprising at least one reticulated three-dimensional microstructure comprising: a network of substantially interconnecting walls provided by a multiplicity of crystals arranged to at least partially abut each other, said crystals defining said walls comprising crystals of a physiologically acceptable support for the therapeutic agent; and a multiplicity of pores defined by said substantially interconnecting walls. 21. A pharmaceutical product according to claim 5, wherein said reticulated microstructure has a specific surface area in the range of 10 to 40 m2g−1. 22. A pharmaceutical product according to claim 1, wherein said therapeutic agent is selected from the group consisting of griseofulvin, acetaminophen, aspirin, mefenamic acid, ibuprofen, ketoprofen, triamterene, naproxen, theophylline, nifedipine, indomethacin, phenytoin, cyclosporin. 23. A pharmaceutical product according to claim 22, said pharmaceutical product comprising a multiplicity of crystals of acetaminophen, said pharmaceutical product comprising at least one reticulated three-dimensional microstructure comprising: a network of substantially interconnecting walls provided by a multiplicity of crystals arranged to at least partially abut each other, said crystals defining said walls consisting essentially of said acetaminophen crystals; and a multiplicity of pores defined by said substantially interconnecting walls. 24. (canceled) 25. A process of preparing a pharmaceutical product as defined in claim 5, which process comprises: forming an emulsion comprising (i) a first phase, (ii) a second phase substantially immiscible with said first phase, and (iii) at least one surfactant; which first phase defines a network of substantially interconnected emulsion channels and comprises a solution comprising at least one therapeutic agent; allowing at least crystals of said at least one therapeutic agent to form in said emulsion channels, whereby a multiplicity of crystals are formed so as to at least partially abut each other so as to be capable of forming the walls of at least one three-dimensional reticulated microstructure; and recovering said crystals from said emulsion. 26. A process according to claim 25, wherein said solution comprising said at least one therapeutic agent further comprises at least one physiologically acceptable support material. 27. A process according to claim 25, wherein the first phase comprises an aqueous phase. 28. A process according to claim 25, wherein the second phase comprises a hydrophobic phase. 29. A process according to claim 25, wherein the surfactant is added to the second phase prior to addition of the second phase to the first phase. 30. A pharmaceutical formulation comprising a pharmaceutical product according to claim 1, together with a pharmaceutically acceptable carrier, diluent or excipient therefor. 31. (canceled) 32. A method of treating a disease, which method comprises administering to a patient a therapeutically effective amount of a pharmaceutical product according to claim 1. |
Method and apparatus for recording a sequence of images using a moving optical element |
An imager (200) including a spatially varying optical element (204) which moves while the imager records a sequence of images. The optical element (204) can be an intensity reduction filter, a spectral or polarization filter, or a refractive or reflective element. Because the optical element (204) moves between frames, each scene portion is captured under a range of imaging conditions. A spatially varying intensity reduction filter enables imaging of each scene portion using multiple, different exposure to generate a high dynamic range image. A spatially varying spectral or polarization filter enables measurement of the spectral or polarization characteristics of radiation from each scene portion. A refractive or reflective element enables imaging of scene portions under various focal characteristics, thereby providing depth information and producing an image which is focused everywhere. A refractive or reflective element is used to apply different vertical and/or horizontal shifts to the different frames, thereby generating an enhanced-resolution image. |
1. A method for imaging a scene, comprising: a step of recording a first image of the scene, comprising: receiving a first radiation ray bundle comprising radiation from a first portion of the scene by a first portion of a first optical element included in an imager having an image detector, the first radiation ray bundle having a first chief ray in a reference frame of the imager, optically processing the first radiation ray bundle by the first portion of the first optical element for producing a second radiation ray bundle, the first portion of the first optical element having a first optical characteristic with respect to radiation ray bundles optically processed by the first portion of the first optical element, measuring an intensity of the second radiation ray bundle by the image detector of the imager to derive a first intensity value, recording the first intensity value, receiving a third radiation ray bundle comprising radiation from a second portion of the scene by a second portion of the first optical element, the third radiation ray bundle having a second chief ray in the reference frame of the imager, the second chief ray being different from the first chief ray, optically processing the third radiation ray bundle by the second portion of the first optical element for producing a fourth radiation ray bundle, the second portion of the first optical element having a second optical characteristic with respect to radiation ray bundles optically processed by the second portion of the first optical element, the second optical characteristic being different from the first optical characteristic, measuring an intensity of the fourth radiation ray bundle by the image detector of the imager to derive a second intensity value, and recording the second intensity value; a step of moving the first optical element in the reference frame of the imager after the step of recording the first image, such that after the step of moving the first optical element, radiation ray bundles having the first chief ray are received by, and optically processed by, at least one of the second portion of the first optical element and a third portion of the first optical element, the third portion of the first optical element having a third optical characteristic with respect to radiation ray bundles optically processed by the third portion of the first optical element, the third optical characteristic being different from the first optical characteristic; a step of recording a second image after the step of moving the first optical element, comprising: receiving a fifth radiation ray bundle comprising radiation from the first portion of the scene by the at least one of the second and third portions of the first optical element, the fifth radiation ray bundle having the first chief ray, optically processing the fifth radiation ray bundle by the at least one of the second and third portions of the first optical element, for producing a sixth radiation ray bundle, measuring an intensity of the sixth radiation ray bundle by the image detector of the imager to derive a third intensity value, and recording the third intensity value; and a step of processing the first and third intensity values to derive at least one value representing at least one of an intensity of radiation emanating from the first portion of the scene, a spectral distribution of radiation emanating from the first portion of the scene, a polarization parameter of radiation emanating from the first portion of the scene, and a distance between the imager and the first portion of the scene. 2. A method according to claim 1, wherein the step of optically processing the first radiation ray bundle comprises reducing an intensity of the first radiation ray bundle by a first intensity reduction factor, the step of optically processing the third radiation ray bundle comprising reducing an intensity of the third radiation ray bundle by a second intensity reduction factor, the second intensity reduction factor being different from the first intensity reduction factor, the step of optically processing the fifth radiation ray bundle comprising reducing an intensity of the fifth radiation ray bundle by a third intensity reduction factor, the third intensity reduction factor being different from the first intensity reduction factor. 3. A method according to claim 1, wherein the step of optically processing the first radiation ray bundle comprises spectrally filtering the first radiation ray bundle according to a first spectral filtering characteristic, the step of optically processing the third radiation ray bundle comprising spectrally filtering the third radiation ray bundle according to a second spectral filtering characteristic, the second spectral filtering characteristic being different from the first spectral filtering characteristic, the step of optically processing the fifth radiation ray bundle comprising spectrally filtering the fifth radiation ray bundle according to a third spectral filtering characteristic, the third spectral filtering characteristic being different from the first spectral filtering characteristic. 4. A method according to claim 3, wherein the first spectral filtering characteristic comprises at least one of a first bandpass characteristic, a first low-pass characteristic, and a first high-pass characteristic, the second spectral filtering characteristic comprising at least one of a second bandpass characteristic, a second low-pass characteristic, and a second high-pass characteristic, the third spectral filtering characteristic comprising at least one of a third bandpass characteristic, a third low-pass characteristic, and a third high-pass characteristic. 5. A method according to claim 1, wherein the step of optically processing the first radiation ray bundle comprises polarization filtering the first radiation ray bundle according to a first polarization filtering characteristic, the step of optically processing the third radiation ray bundle comprising polarization filtering the third radiation ray bundle according to a second polarization filtering characteristic, the second polarization filtering characteristic being different from the first polarization filtering characteristic, the step of optically processing the fifth radiation ray bundle comprising polarization filtering the fifth radiation ray bundle according to a third polarization filtering characteristic, the third polarization filtering characteristic being different from the first polarization filtering characteristic. 6. A method according to claim 1, wherein the step of optically processing the first radiation ray bundle comprises adjusting by a first focus distance adjustment amount an object distance of best focus associated with the first radiation ray bundle, the step of optically processing the third radiation ray bundle comprising adjusting by a second focus distance adjustment amount an object distance of best focus associated with the third radiation ray bundle, the second focus distance adjustment amount being different from the first focus distance adjustment amount, the step of optically processing the fifth radiation ray bundle comprising adjusting by a third focus distance adjustment amount an object distance of best focus associated with the fifth radiation ray bundle, the third focus distance adjustment amount being different from the first focus distance adjustment amount. 7. A method according to claim 1, wherein the step of optically processing the first radiation ray bundle comprises deflecting the first radiation ray bundle by a first deflection amount, the step of optically processing the third radiation ray bundle comprising deflecting the third radiation ray bundle by a second deflection amount, the second deflection amount being different from the first deflection amount, the step of optically processing the fifth radiation ray bundle comprising deflecting the fifth radiation ray bundle by a third deflection amount, the third deflection amount being different from the first deflection amount. 8. A method according to claim 1, wherein the imager further includes a second optical element, the step of recording the first image of the scene further comprising: receiving a seventh radiation ray bundle comprising radiation from the first portion of the scene by a first portion of the second optical element; optically processing the seventh radiation ray bundle by the first portion of the second optical element for producing the first radiation ray bundle, the first portion of the second optical element having a fourth optical characteristic with respect to the seventh radiation ray bundle; receiving an eighth radiation ray bundle comprising radiation from the second portion of the scene by a second portion of the second optical element; and optically processing the eighth radiation ray bundle by the second portion of the second optical element for producing the third radiation ray bundle, the second portion of the second optical element having a fifth optical characteristic with respect to the eighth radiation ray bundle, the method further comprising a step of moving the second optical element in the reference frame of the imager between the step of recording the first image and the step of recording the second image, such that, after the step of moving the second optical element, a ninth radiation ray bundle is received by a third portion of the second optical element, the third portion of the second optical element having a sixth optical characteristic with respect to the ninth radiation ray bundle, the sixth optical characteristic being different from the fourth optical characteristic, the step of recording the second image further comprising optically processing the ninth radiation ray bundle by the at least one of the second and third portions of the second optical element for producing the fifth radiation ray bundle. 9. A method for imaging a scene, comprising: continuously moving in repetitive fashion an optical element in a reference frame of an imager, the optical element comprising at least one of a refractive element, a reflective element, and an interference filter, the imager including an image detector, the step of continuously moving the optical element comprising moving the optical element into a first position in the reference frame of the imager during a first time period, and moving the optical element into a second position in the reference frame of the imager during a second time period, the second position being different from the first position; receiving a first set of radiation ray bundles comprising radiation from the scene by the optical element during the first time period; optically processing the first set of radiation ray bundles by the optical element during the first time period for producing a second set of radiation ray bundles; detecting intensities of the second set of radiation ray bundles by the image detector during the first time period for deriving a first set of intensity values; recording the first set of intensity values as a first image; receiving a third set of radiation ray bundles comprising radiation from the scene by the optical element during the second time period; optically processing the third set of radiation ray bundles by the optical element during the second time period for producing a fourth set of radiation ray bundles; and detecting intensities of the fourth set of radiation ray bundles by the image detector during the second time period for deriving a second set of intensity values; recording the second set of intensity values as a second image; and processing the first and second images to derive a third image having at least one of: (a) an enhanced spatial resolution greater than a respective spatial resolutions of the first and second images, and (b) an enhanced spectral resolution greater than respective spectral resolutions of the first and second images. 10. A method according to claim 9, wherein the optical element comprises at least one of the refractive element and the reflective element, the image detector including a plurality of detector elements disposed in an array, each of the plurality of detector elements having one of a plurality of detector element center locations, the first set of radiation ray bundles including a first radiation ray bundle, the second set of radiation ray bundles including a second radiation ray bundle, the step of optically processing the first set of radiation ray bundles including optically processing the first radiation ray bundle by the optical element for producing the second radiation ray bundle, the first radiation ray bundle having a first chief ray in the reference frame of the imager, the second radiation ray bundle having a second chief ray in the reference frame of the imager, the second chief ray impinging upon none of the detector element center locations, the third set of radiation ray bundles including a third radiation ray bundle, the fourth set of radiation ray bundles including a fourth radiation ray bundle, the step of optically processing the third set of radiation ray bundles including optically processing the third radiation ray bundle by the optical element for producing the fourth radiation ray bundle, the third radiation ray bundle having the first chief ray, the fourth radiation ray bundle having a third chief ray in the reference frame of the imager, the third chief ray impinging upon one of the plurality of detector element center locations. 11. A method according to claim 9, wherein the optical element comprises the interference filter, the first set of radiation ray bundles including a first radiation ray bundle, the first radiation ray bundle having a first chief ray in the reference frame of the imager, the step of optically processing the first set of radiation ray bundles including spectrally filtering the first radiation ray bundle by the interference filter according to a first spectral filtering characteristic thereof, the third set of radiation ray bundles including a second radiation ray bundle, the second radiation ray bundle having the first chief ray, the step of optically processing the third set of radiation ray bundles including spectrally filtering the second radiation ray bundle by the interference filter according to a second spectral filtering characteristic thereof, the second spectral filtering characteristic being different from the first spectral filtering characteristic. 12. An imager, comprising: a focusing element; a first optical element, comprising: a first optical element portion for receiving a first radiation ray bundle comprising first radiation from a first portion of a scene during a first time period, the focusing element for focusing the first radiation from the first portion of the scene, the first radiation ray bundle having a first chief ray in a reference frame of the imager, the first optical element portion for optically processing the first radiation ray bundle for producing a second radiation ray bundle, the first optical element portion having a first optical characteristic with respect to the first radiation ray bundle, a second optical element portion for receiving a third radiation ray bundle comprising first radiation from a second portion of the scene during the first time period, the focusing element for focusing the first radiation from the second portion of the scene, the third radiation ray bundle having a second chief ray in the reference frame of the imager, the second chief ray being different from the first chief ray, the second optical element portion for optically processing the third radiation ray bundle for producing a fourth radiation ray bundle, the second optical element portion having a second optical characteristic with respect to the third radiation ray bundle, the second optical characteristic being different from the first optical characteristic, and a third optical element portion having a third optical characteristic with respect to radiation ray bundles optically processed thereby, the third optical characteristic being different from the first optical characteristic; an optical element driver for moving the first optical element in the reference frame of the imager during a second time period after the first time period, such that during a third time period after the second time period, a fifth radiation ray bundle comprising a second radiation from the first portion of the scene is received by at least one of the second and third optical element portions, the focusing element for focusing the second radiation from the first portion of the scene, the fifth radiation ray bundle having the first chief ray, and the at least one of the second and third optical element portions being for optically processing the fifth radiation ray bundle for producing a sixth radiation ray bundle; an image detector for measuring, during the first time period, an intensity of the second radiation ray bundle and an intensity of the fourth radiation ray bundle for deriving first and second intensity values, respectively, the image detector for measuring an intensity of the sixth radiation ray bundle during the third time period, for deriving a third intensity value; at least one memory for recording the first and second intensity values as part of a first image, the at least one memory for recording the third intensity value as a part of a second image; and a processor for processing the first and third intensity values to derive at least one value representing at least one of an intensity of radiation emanating from the first portion of the scene, a spectral distribution of radiation emanating from the first portion of the scene, a polarization parameter of radiation emanating from the first portion of the scene, and a distance between the imager and the first portion of the scene. 13. An imager according to claim 12, wherein the first optical element portion comprises a first radiation intensity reduction filter portion, the second optical element portion comprising a second radiation intensity reduction filter portion, the third optical element portion comprising a third radiation intensity reduction filter portion, the first optical characteristic comprising a first intensity reduction factor, the second optical characteristic comprising a second intensity reduction factor, the second intensity reduction factor being different from the first intensity reduction factor, the third optical characteristic comprising a third intensity reduction factor, the third intensity reduction factor being different from the first intensity reduction factor. 14. An imager according to claim 12, wherein the first optical element portion comprises a first spectral filter portion, the second optical element portion comprising a second spectral filter portion, the third optical element portion comprising a third spectral filter portion, the first optical characteristic comprising a first spectral filtering characteristic, the second optical characteristic comprising a second spectral filtering characteristic, the second spectral filtering characteristic being different from the first spectral filtering characteristic, the third optical characteristic comprising a third spectral filtering characteristic, the third spectral filtering characteristic being different from the first spectral filtering characteristic. 15. An imager according to claim 14, wherein the first spectral filtering characteristic comprises at least one of a first bandpass characteristic, a first low-pass characteristic, and a first high-pass characteristic, the second filtering characteristic comprising at least one of a second bandpass characteristic, a second low-pass characteristic, and a second high-pass characteristic, and the third spectral filtering characteristic comprising at least one of a third bandpass characteristic, a third low-pass characteristic, and a third high-pass characteristic. 16. An imager according to claim 12, wherein the first optical element portion comprises a first polarization filter portion, the second optical element portion comprising a second polarization filter portion, the third optical element portion comprising a third polarization filter portion, the first optical characteristic comprising a first polarization filtering characteristic, the second optical characteristic comprising a second polarization filtering characteristic, the second polarization filtering characteristic being different from the first polarization filtering characteristic, the third optical characteristic comprising a third polarization filtering characteristic, and the third polarization filtering characteristic being different from the first polarization filtering characteristic. 17. An imager according to claim 12, wherein the first optical element portion comprises at least one of a first refractive element portion and a first reflective element portion, the second optical element portion comprising at least one of a second refractive element portion and a second reflective element portion, the third optical element portion comprising at least one of a third refractive element portion and a third reflective element portion, the first optical characteristic comprising an amount of adjustment of an object distance of best focus associated with radiation ray bundles processed by the first optical element portion, the second optical characteristic comprising an amount of adjustment of an object distance of best focus associated with radiation ray bundles processed by the second optical element portion, the amount of adjustment of the object distance of best focus associated with radiation ray bundles processed by the second optical element portion being different from the amount of adjustment of the object distance of best focus associated with radiation ray bundles processed by the first optical element portion, the third optical characteristic comprising an amount of adjustment of an object distance of best focus associated with radiation ray bundles processed by the third optical element portion, and the amount of adjustment of the object distance of best focus associated with radiation ray bundles processed by the third optical element portion being different from the amount of adjustment of the object distance of best focus associated with radiation ray bundles processed by the first optical element portion. 18. An imager according to claim 12, wherein the first optical element portion comprises at least one of a first refractive element portion and a first reflective element portion, the second optical element portion comprising at least one of a second refractive element portion and a second reflective element portion, the third optical element portion comprising at least one of a third refractive element portion and a third reflective element portion, the first optical characteristic comprising an amount of deflection of radiation ray bundles processed by the first optical element portion, the second optical characteristic comprising an amount of deflection of radiation ray bundles processed by the second optical element portion, the amount of deflection of radiation ray bundles processed by the second optical element portion being different from the amount of deflection of radiation ray bundles processed by the first optical element portion, the third optical characteristic comprising an amount of deflection of radiation ray bundles processed by the third optical element portion, the amount of deflection of radiation ray bundles processed by the third optical element portion being different from the amount of deflection of radiation ray bundles processed by the first optical element portion. 19. An imager according to claim 12, further comprising: a second optical element, comprising: a fourth optical element portion for receiving a seventh radiation ray bundle comprising third radiation from the first portion of the scene during the first time period, the focusing element for focusing the third radiation from the first portion of the scene, the fourth optical element portion for optically processing the seventh radiation ray bundle for producing the first radiation ray bundle, and the fourth optical element portion having a fourth optical characteristic with respect to the seventh radiation ray bundle, a fifth optical element portion for receiving an eighth radiation ray bundle comprising second radiation from the second portion of the scene during the first time period, the focusing element for focusing the second radiation from the second portion of the scene, the fifth optical element portion for optically processing the eighth radiation ray bundle for producing the third radiation ray bundle, the fifth optical element portion having a fifth optical characteristic with respect to the eighth radiation ray, and a sixth optical element portion having a sixth optical characteristic with respect to radiation ray bundles optically processed thereby, the sixth optical characteristic being different from the fourth optical characteristic; and an optical element driver for moving the second optical element in the reference frame of the imager during the second time period, such that during the third time period, a ninth radiation ray bundle comprising fourth radiation from the first portion of the scene is received by the sixth optical element portion, the focusing element for focusing the fourth radiation from the first portion of the scene, the sixth optical element portion for optically processing the ninth radiation ray bundle for producing the fifth radiation ray bundle. 20. An imager, comprising: an optical element comprising at least one of a refractive element, a reflective element, and an interference filter; an optical element driver for continuously moving in repetitive fashion the optical element in a reference frame of the imager, the optical element driver for moving the optical element into a first position in the reference frame of the imager during a first time period, the optical element for receiving a first set of radiation ray bundles during the first time period, the optical element for optically processing the first set of radiation ray bundles for producing a second set of radiation ray bundles, the optical element driver for moving the optical element into a second position in the reference frame of the imager during a second time period, the second position being different from the first position, the optical element for receiving a third set of radiation ray bundles during the second time period, and the optical element for optically processing the third set of radiation ray bundles during the second time period for producing a fourth set of radiation ray bundles; an image detector for detecting intensities of the second set of radiation ray bundles during the first time period for deriving a first set of intensity values, the image detector for detecting intensities of the fourth set of radiation ray bundles during the second time period for deriving a second set of intensity values; at least one memory for recording the first set of intensity values as a first image, the at least one memory for recording the second set of intensity values as a second image; and a processor for processing the first and second images to derive a third image having at least one of: (a) an enhanced spatial resolution greater than a respective spatial resolutions of the first and second images, and (b) an enhanced spectral resolution greater than respective spectral resolutions of the first and second images. 21. An imager according to claim 20, wherein the optical element comprises at least one of the refractive element and the reflective element, the image detector including a plurality of detector elements disposed in an array, each of the plurality of detector elements having a respective one of a plurality of detector element center locations, the first set of radiation ray bundles including a first radiation ray bundle, the second set of radiation ray bundles including a second radiation ray bundle, the at least one of the refractive element and the reflective element being for optically processing the first radiation ray bundle during the first time period, for producing the second radiation ray bundle, the first radiation ray bundle having a first chief ray in the reference frame of the imager, the second radiation ray bundle having a second chief ray in the reference frame of the imager, the second chief ray impinging on none of the detector element center locations, the third set of radiation ray bundles including a third radiation ray bundle, the fourth set of radiation ray bundles including a fourth radiation ray bundle, the at least one of the refractive element and the reflective element for optically processing the third radiation ray bundle during the second time period for producing the fourth radiation ray bundle, the third radiation ray bundle having the first chief ray, the fourth radiation ray bundle having a third chief ray in the reference frame of the imager, the third chief ray impinging on one of the plurality of detector element center locations. 22. An imager according to claim 20, wherein the optical element comprises the interference filter, the first set of radiation ray bundles including a first radiation ray bundle, the first radiation ray bundle having a first chief ray in the reference frame of the imager, the second set of radiation ray bundles including a second radiation ray bundle, the interference filter for spectrally filtering the first radiation ray bundle according to a first spectral filtering characteristic for producing the second radiation ray bundle, the third set of radiation ray bundles including a third radiation ray bundle, the third radiation ray bundle having the first chief ray, the fourth set of radiation ray bundles including a fourth radiation ray bundle, the interference filter for spectrally filtering the third radiation ray bundle according to a second spectral filtering characteristic for producing the fourth radiation ray bundle, the second spectral filtering characteristic being different from the first spectral filtering characteristic. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Conventional imagers suffer from shortcomings with respect to the quality of data they can produce. For example, a typical imager has limited spatial resolution and has limited dynamic range for measuring the brightness, color, and polarization of light. For example, conventional cameras can have spatial resolution as low as 640×480 pixels, and color resolution as low as 8 bits. Furthermore, most non-stereoscopic imagers are unable to measure scene depth—i.e., the distance between the imager and the object being imaged. Such limitations render many conventional imagers inadequate for certain computational vision tasks such as, for example, feature detection, object recognition, motion measurement, and scene reconstruction. Efforts have been made to enhance the quality of image data generated by video and still cameras. For example, in order to enhance the resolution and dynamic range of image data, and/or to provide additional information such as polarization data, it is possible to record multiple images of the same scene, each image taken under a different camera configuration. In one such technique, illustrated in FIG. 21 , a filter wheel 2104 containing several different optical filters 2106 is mounted in front of the objective lens 2102 of a camera 2108 . Each of the filters 2106 has a different optical characteristic such as a particular intensity reduction factor, spectral filtering characteristic, polarization filtering characteristic, or other optical characteristic. Each image is recorded using a different filter 2106 . Between images the filter wheel 2104 is rotated about an axis of rotation 2110 . However, such a filtering technique tends to be cumbersome, because the filters 2106 must be sufficiently large to cover the field of view of the camera 2108 . This requirement makes the filter wheel 2104 bulky and heavy, and therefore, a substantial amount of energy is required to move the filter wheel 2104 between frames. As a result, the frame rate of the system tends to be too slow for real-time imaging. In addition, such an arrangement requires each image to be recorded through a single filter 2106 , and therefore, the switching of the filters 2106 must be synchronized with the image frames. The limited speed at which the filters 2106 can be switched thus reduces the rate at which images can be captured. Furthermore, synchronization requires additional timing circuitry. |
<SOH> SUMMARY OF THE INVENTION <EOH>It is therefore an object of the present invention to provide an imaging system having enhanced spatial resolution, as well as enhanced resolution and dynamic range with respect to color, polarization, depth, and brightness. It is a further object of the present invention to provide an imaging system which provides such enhanced resolution and dynamic range without substantially reducing the rate at which images can be recorded. These and other objects are accomplished by the following aspects of the present invention. In accordance with one aspect of the present invention, a method for imaging comprises the steps of: (1) recording a first image using an optical element having first and second portions; (2) moving the optical element in the reference frame of an imager after the step of recording the first image; and (3) recording a second image using the optical element after the step of moving the optical element. The step of recording the first image comprises: (a) receiving a first radiation ray bundle by a first portion of the optical element, the first radiation ray bundle having a first chief ray in the reference frame of the imager; (b) optically processing the first radiation ray bundled by the first portion of the optical element, for producing a second radiation ray bundle, the first portion of the optical element having a first optical characteristic with respect to the radiation ray bundles that it optically processes; (c) measuring the intensity of the second radiation ray bundle by an image detector which is included in the imager; (d) receiving a third radiation ray bundle by a second portion of the optical element, the third radiation ray bundle having a second chief ray in the reference frame of imager, the second chief ray being different from the first chief ray; (e) optically processing the third radiation ray bundle by the second portion of the first optical element, for producing a fourth radiation ray bundle, the second portion of the first optical element having a second optical characteristic with respect to radiation ray bundles that it optically processes, and the second optical characteristic being different from the first optical characteristic; and (f) measuring the intensity of the fourth radiation ray bundle by the image detector. After the step of moving the optical element, radiation ray bundles having the first chief ray are received, and optically processed, by at least one of the second portion of the optical element and a third portion of the optical element, the third portion having a third optical characteristic with respect to radiation ray bundles that it optically processes, and the third optical characteristic being different from the first optical characteristic. The step of recording the second image comprises: (a) receiving a fifth radiation ray bundle by the at least one of the second and third portions of the optical element, the fifth radiation ray bundle having the first chief ray; (b) optically processing the fifth radiation ray bundle by the at least one of the second and third portions of the optical element, for producing a sixth radiation ray bundle; and (c) measuring the intensity of the sixth radiation ray bundle by the image detector. In accordance with an additional aspect of the present invention, a method for imaging comprises the steps of: (1) continuously moving an optical element in a reference frame of an imager, the optical element comprising a refractive element, a reflective element, and/or an interference filter, the imager including an image detector, and the step of continuously moving the optical element comprising: (a) moving the optical element into a first position in the reference frame of the imager during a first time period, and (b) moving the optical element into a second position in the reference frame of the imager during a second time period, the second position being different from the first position; (2) receiving a first set of radiation ray bundles by the optical element during the first time period; (3) optically processing the first set of radiation ray bundles by the optical element during the first time period, for producing a second set of radiation ray bundles; (4) detecting the second set of radiation ray bundles by the image detector during the first time period, for recording a first image; (5) receiving a third set of radiation ray bundles by the optical element during the second time period; (6) optically processing the third set of radiation ray bundles by the optical element during the second time period, for producing a fourth set of radiation ray bundles; and (7) detecting the fourth set of radiation ray bundles by the image detector during the second time period, for recording a second image. |
Method and device for producing individualized holograms |
The present invention relates to methods of producing an individualized digital computer-generated hologram, in which the technical problem of being able to draw conclusions from the holograms about the associated writing device is achieved in that a hologram is written into a storage medium as a matrix of individual points, in that a geometric pattern for writing the holographic information in is predefined, and in that an individualizing feature is superimposed on the hologram by writing in a large number of individual points deviating from the predefined pattern. The invention also relates to a reading method and a storage medium having an individualized hologram. |
1. A method of producing an individualized digital computer-generated hologram, in which the hologram is written in a storage medium as a matrix of individual points, in which a geometric pattern for writing the holographic information in is predefined and in which an individualizing feature is superimposed on the hologram by writing in a large number of individual points deviating from the predefined pattern. 2. The method as claimed in claim 1, in which the points deviating from the pattern are written in deviating systematically from their normal positions predefined by the pattern. 3. The method as claimed claim 2, in which the systematic deviations from a normal position are produced in at least one direction. 4. The method as claimed in claim 3, in which the systematic deviations from the normal position are produced periodically. 5. The method as claimed in claim 4, in which the period of the deviations is chosen to be greater than the grid spacing of the pattern. 6. The method as claimed in claim 2, in which, in addition to the points to be written in in the predefined pattern, points in the form of a geometric pattern are written in at locations deviating from the pattern. 7. The method as claimed in claim 2, in which an orthogonal pattern is chosen as the pattern, and in which the individual points of the hologram are at least partly written in in a hexagonal pattern. 8. The method as claimed in claim 1, in which the points deviating from the pattern are written in deviating non-systematically from the pattern. 9. The method as claimed in claim 8, in which the deviations are produced by omitting and/or inserting individual points. 10. The method as claimed in claim 8, characterized in that the deviations are produced by displacing individual points from their normal positions predefined by the pattern. 11. A method of reading an individualized digital computer-generated hologram, in which the hologram written in a storage medium is illuminated with a beam of electromagnetic radiation, the hologram having basic information and at least one individualizing feature, in which the image produced by the hologram is recorded by recording means and evaluated with the aid of image recognition, and in which the at least one individualizing feature contained in the hologram is checked. 12. A storage medium having a digital computer-generated hologram, having individual points which are written in the material of the storage medium, are arranged in a predefined geometric pattern and form the hologram, having a large number of individual points which are written in the material of the storage medium deviating from the predefined pattern. |
3,7-Diazabicyclo [3.3.1]formulations as anti-arrhythmic compounds |
There is provided immediate release pharmaceutical formulations comprising, as active ingredient, 4-([3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl]amino)benzonitrile, tert-butyl 2-{7-[3-(4-cyanoanilino)propyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethyl-carbamate, tert-butyl 2-{7-[4-(4-cyanophenyl)butyl]-9-oxa-3,7-diaza-bicyclo[3.3.1]non-3-yl}ethylcarbamate or tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate, or a pharmaceutically-acceptable salt of any of these compounds, and a pharmaceutically-aceptable diluent or carrier. There is further provided solid pharmaceutical compositions comprising an above-stated active ingredient, which compositions are suitable for the preparation of immediate release pharmaceutical formulations, and which compositions may be prepared for example by freeze-drying. The formulations and compositions are useful in the prophylaxis and/or treatment of cardiac arrhythmias. |
1. An immediate-release pharmaceutical formulation comprising, as active ingredient, 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile, tert-butyl 2-{7-[3-(4-cyanoanilino)propyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate, tert-butyl 2-{7-[4-(4-cyanophenyl)butyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate or tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate or a pharmaceutically-acceptable salt of any of these compounds; and a pharmaceutically-acceptable diluent or carrier. 2. A formulation as claimed in claim 1, which releases at least 70% of the active ingredient within 4 hours of administration. 3. A formulation as claimed in claim 2, wherein at least 80% of active ingredient is released. 4. A formulation as claimed in claim 2 or claim 3, wherein the release is within 1 hour. 5. A formulation as claimed in claim 4, wherein the release is within 30 minutes. 6. A formulation as claimed in any one of the preceding claims which is adapted for peroral administration. 7. A formulation as claimed in claim 6, which is in the form of a tablet, a capsule or a liquid dosage form. 8. A formulation as claimed in claim 7, which is in the form of an immediate release tablet comprising active ingredient, diluent or carrier, and, optionally, one or more additional excipients. 9. A formulation as claimed in claim 8, wherein the diluent or carrier is monobasic calcium phosphate, dibasic calcium phosphate (dihydrate or anhydrate), tribasic calcium phosphate, lactose, microcrystalline cellulose, silicified microcrystalline cellulose, mannitol, sorbitol, maize starch, potato starch, rice starch, glucose, calcium lactate or calcium carbonate. 10. A formulation as claimed in claim 9, wherein the diluent or carrier is dibasic calcium phosphate (dihydrate or anhydrate) or microcrystalline cellulose. 11. A formulation as claimed in any one of claims 8 to 10, wherein the optional additional excipient(s) comprise(s) a lubricant, a glidant, a binder and/or a disintegrant. 12. A formulation as claimed in claim 11, wherein the lubricant is magnesium stearate, stearic acid, calcium stearate, stearyl alcohol or sodium stearyl fumarate 13. A formulation as claimed in claim 12, wherein the lubricant is magnesium stearate or sodium stearyl fumarate. 14. A formulation as claimed in any one of claims 11 to 13, wherein the lubricant is talc or a colloidal silica. 15. A formulation as claimed in any one of claims 11 to 14, wherein the binder is polyvinylpyrrolidone, microcrystalline cellulose, a polyethylene glycol, a polyethylene oxide, a hydroxypropylmethylcellulose of a low molecular weight, a methylcellulose of a low molecular weight, a hydroxypropylcellulose of a low molecular weight, a hydroxyethylcellulose of a low molecular weight, maize starch, potato starch, rice starch or a sodium carboxymethyl cellulose of a low molecular weight. 16. A formulation as claimed in claim 15, wherein the binder is polyvinylpyrrolidone or a hydroxypropylmethylcellulose of a low molecular weight. 17. A formulation a claimed in any one of claims 11 to 16, wherein the disintegrant is sodium starch glycolate, crosslinked polyvinylpyrrolidone, crosslinked sodium carboxymethyl cellulose, maize starch, potato starch, rice starch or an alginate. 18. A formulation a claimed in claim 17, wherein the disintegrant is sodium starch glycolate, crosslinked polyvinylpyrrolidone or crosslinked sodium carboxymethyl cellulose. 19. A formulation as claimed in any one of claims 8 to 18, wherein the amount of diluent/carrier in the formulation is up to 40% (w/w) of the final formulation. 20. A formulation as claimed in claim 19, wherein the amount of diluent/carrier is up to 30% (w/w). 21. A formulation as claimed in claim 20, wherein the amount of diluent/carrier is up to 20% (w/w). 22. A formulation as claimed in claim 21, wherein the amount of diluent/carrier is up to 10% (w/w). 23. A formulation as claimed in any one of claims 8 to 22, wherein the amount of additional excipient(s) is up to 5% (w/w) of the final formulation when the excipient(s) is/are a lubricant and/or a glidant. 24. A formulation as claimed in any one of claims 8 to 22, wherein the amount of additional excipient(s) is up to 10% (w/w) of the final formulation when the excipient(s) is/are a binder and/or a disintegrant. 25. A formulation as claimed in any one of claims 1 to 5 which is adapted for parenteral administration. 26. A formulation as claimed in claim 25, wherein the administration is subcutaneous, intravenous, intraarterial, transdermal, intranasal, intrabuccal, intracutaneous, intramuscular, intralipomateous, intraperitoneal, rectal, sublingual, topical or by inhalation. 27. A formulation as claimed in any one of claims 1 to 5, 25 or 26, wherein the diluent or carrier is an aqueous carrier. 28. A formulation as claimed in any one of claims 1 to 5 or 25 to 27 wherein the formulation comprises one or more additional excipients. 29. A formulation as claimed in claim 28 (as dependent on claim 27), wherein the excipient(s) is/are selected from the group antimicrobial preservatives, tonicity modifiers, pH adjusting agents, pH controlling agents, surfactants, cosolvents and/or antioxidants. 30. A formulation as claimed in claim 29, wherein the tonicity modifier is selected from sodium chloride, mannitol or glucose. 31. A formulation as claimed in claim 29 or claim 30, wherein the pH adjusting agent is hydrochloric acid or sodium hydroxide. 32. A formulation as claimed in any one of claims 29 to 31, wherein the pH controlling agent is tartaric acid, acetic acid or citric acid. 33. A formulation as claimed in any one of claims 29 to 32, wherein the cosolvent is ethanol, a polyethylene glycol or hydroxypropyl-β-cyclodextrin. 34. A formulation as claimed in any one of the preceding claims, in which the active ingredient is provided in the form of a methanesulphonic acid, a tartaric acid, a succinic acid, a citric acid, an acetic acid, a hippuric acid, a hydrochloric acid, or a hydrobromic acid, salt. 35. A formulation as claimed in any one of the preceding claims in which the active ingredient is 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile or tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate, or a pharmaceutically acceptable salt of either compound. 36. A formulation as claimed in claim 35, wherein the active ingredient is 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile or a pharmaceutically acceptable salt thereof. 37. A formulation as claimed in claim 36 in which, when the active ingredient is a salt of 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile, it is a 1-hydroxy-2-naphthoic acid, a benzoic acid, a hydroxybenzenesulphonic acid, a benzenesulphonic acid, a toluenesulphonic acid, a naphthalenesulphonic acid, a naphthalenedisulphonic acid, a mesitylenesulphonic acid, a methanesulphonic acid, a tartaric acid, a succinic acid, a citric acid, an acetic acid, a hippuric acid, a benzoic acid, a hydrochloric acid, or a hydrobromic acid, salt. 38. A formulation as claimed in claim 35, wherein the active ingredient is tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]-non-3-yl}ethylcarbamate or a pharmaceutically acceptable salt thereof. 39. A formulation as claimed in claim 38, wherein the active ingredient is tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate. 40. A formulation as claimed in claim 38 in which, when the active ingredient is a salt of tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]-non-3-yl}ethylcarbamate, it is a L-lysine monohydrochloride, a pamoic acid, a terephthalic acid, a methanesulphonic acid, a tartaric acid, a succinic acid, a citric acid, an acetic acid, a hippuric acid, a benzoic acid, a hydrochloric acid, or a hydrobromic acid, salt. 41. A formulation as claimed in claim 40 in which the salt is a methanesulphonic acid, a tartaric acid, a citric acid, or an acetic acid, salt. 42. A formulation as claimed in claim 41 in which the salt is a methanesulphonic acid salt. 43. A formulation as claimed in any one of claims 1 to 5 or 25 to 37 wherein, when the formulation of the invention comprises 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile, either as the free base, as the para-toluenesulphonic acid salt, or as the benzenesulphonic acid salt, and an aqueous carrier, along with ethanol as sole additional excipient, then the ethanol content is no more than 10% (w/w) of the content of the carrier. 44. A formulation as claimed in any one of claims 1 to 5 or 25 to 43 which is an aqueous solution. 45. A formulation as claimed in any one of the preceding claims in which the active ingredient is water soluble. 46. A formulation as claimed in claim 45, in which the solubility of active ingredient in aqueous solutions is at least 1 mg/mL. 47. A formulation as claimed in claim 46, in which the solubility is at least 2 mg/mL. 48. A process for the preparation of a formulation as defined in any one of the preceding claims, which process comprises bringing active ingredient into association with a pharmaceutically-acceptable diluent or carrier. 49. A process as claimed in claim 48 for the formation of a formulation as claimed in any one of claims 6 to 24 which further comprises wet or dry granulation, and/or direct compression/compaction of active ingredient and diluent/carrier. 50. A process as claimed in claim 48 for the formation of a formulation as claimed in any one of claims 25 to 47 wherein, when active ingredient is in the form of an acid addition salt, the process further comprises addition of acid to 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile, tert-butyl 2-{7-[3-(4-cyanoanilino)propyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate, tert-butyl 2-{7-[4-(4-cyanophenyl)butyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate or tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate. 51. A process as claimed in claim 50, wherein one or both of the acid or the base is provided in association with a diluent or carrier. 52. A process as claimed in claim 50, wherein diluent or carrier is added to a mixture of acid and base. 53. A formulation as claimed in any one of claims 1 to 5 or 25 to 47 which is suitable for direct administration to a patient. 54. A formulation as defined in any one of claims 1 to 5 or 25 to 47 which is provided in the form of a concentrate of active ingredient and diluent or carrier, which concentrate is suitable for preparation of a formulation as claimed in claim 53 by way of addition of further diluent or carrier prior to administration. 55. A process for the preparation of a formulation as defined in claim 54, which comprises a process as defined in any one of claims 48 or 50 to 52 followed by, if appropriate, concentration of the resultant formulation by removal of diluent or carrier. 56. A process as claimed in claim 55, wherein the process of removal of diluent or carrier comprises evaporation (under reduced pressure or otherwise). 57. A process for the preparation of a formulation as defined in claim 53 which comprises addition of diluent or carrier to a formulation as defined in claim 54. 58. A solid pharmaceutical composition suitable for use in the preparation of a formulation as claimed in any one of claims 1 to 5, 25 to 47, 53 or 54 ex tempore, which composition comprises an active ingredient as defined in claim 1. 59. A composition as claimed in claim 58, which comprises active ingredient, one or more optional further excipients as defined in any one of claims 28 to 33 and/or, optionally, up to 10% (w/w) of pharmaceutically-acceptable diluent or carrier. 60. A composition as claimed in claim 58 or claim 59, wherein, when the active ingredient is in the form of 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile, 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile, benzenesulphonic acid salt, tert-butyl 2-{7-[3-(4-cyanoanilino)propyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate, tert-butyl 2-{7-[4-(4-cyanophenyl)butyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate, or tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate, then the composition comprises either one or more further excipients, or up to 10% (w/w) diluent or carrier. 61. A composition as claimed in any one of claims 58 to 60, which composition is suitable for preparation of a pharmaceutically-acceptable solution ex tempore. 62. A composition as claimed in claim 61, wherein the solution is an aqueous solution. 63. A composition as claimed in any one of claims 58 to 62, wherein a further excipient is present which aids the formation of the solid composition during a process of removal of diluent or carrier. 64. A composition as claimed in claim 63, wherein the further excipient is mannitol. 65. A process for the formation of a composition as claimed in any one of claims 58 to 64 which comprises removal of diluent or carrier from a formulation as defined in any one of claims 1 to 5, 25 to 47, 53 or 54. 66. A process as claimed in claim 65, wherein the diluent or carrier is removed by evaporation (under reduced pressure or otherwise), spray drying or freeze-drying. 67. A process as claimed in claim 66, wherein the diluent or carrier is removed by freeze drying. 68. A composition obtainable by a process according to any one of claims 65 to 67. 69. A freeze-dried composition as defined in any one of claims 58 to 64. 70. A formulation as defined in any one of claims 1 to 47, 53 or 54, or a composition as defined in any one of claims 58 to 64, 68 or 69, for use in medicine. 71. A formulation as defined in any one of claims 1 to 47, 53 or 54, or a composition as defined in any one of claims 58 to 64, 68 or 69, for use in the prophylaxis or the treatment of an arrhythmia. 72. The use of a formulation as defined in any of one claims 1 to 47, 53 or 54, or a composition as defined in any one of claims 58 to 64, 68 or 69, for the manufacture of a medicament for use in the prophylaxis or the treatment of an arrhythmia. 73. The use as claimed in claim 72, wherein the arrhythmia is an atrial or a ventricular arrhythmia. 74. The use as claimed in claim 72, wherein the arrhythmia is atrial fibrillation. 75. The use as claimed in claim 72, wherein the arrhythmia is atrial flutter. 76. A method of prophylaxis or treatment of an arrhythmia which method comprises administration of a formulation as defined in any one of claims 1 to 47 or 53 to a person suffering from, or susceptible to, such a condition. 77. The method as claimed in claim 76 wherein the arrhythmia is an atrial or a ventricular arrhythmia. 78. The method as claimed in claim 76, wherein the arrhythmia is atrial fibrillation. 79. The method as claimed in claim 76, wherein the arrhythmia is atrial flutter. |
<SOH> BACKGROUND AND PRIOR ART <EOH>It is often desirable to formulate pharmaceutically-active compounds for immediate release following oral and/or parenteral administration with a view to providing a sufficient concentration of drug in plasma within the time-frame required to give rise to a desired therapeutic response. Immediate release may be particularly desirable in cases where, for example, a rapid therapeutic response is required (e.g. in the treatment of acute problems), or, in the case of parenteral administration, when peroral delivery to the gastrointestinal tract is incapable of providing sufficient systemic uptake within the required time-frame. In the case of the treatment or prophylaxis of cardiac arrhythmias, immediate release formulations may be necessary to ensure that a sufficient amount of drug is provided in plasma within a relatively short period of time to enable, for example, rapid conversion of atrial fibrillation (AF) to sinus rhythm, or prevention of relapse into AF in vulnerable patients. Immediate release formulations are also typically simpler to develop than modified release formulations, and may also provide more flexibility in relation to the variation of doses that are to be administered to patients. International patent application WO 01/28992 discloses a number of oxabispidine compounds, including: (a) 4-({3-[7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl]propyl}amino)benzonitrile: which compound is referred to hereinafter as Compound A. Compound A is specifically disclosedin WO 01/28992, both in the form of the free base and in the form of a benzenesulphonate salt; (b) tert-butyl 2-{7-[3-(4-cyanoanilino)propyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate: in the form of the free base, which compound is referred to hereinafter as Compound B; (c) tert-butyl 2-{7-[4-(4-cyanophenyl)butyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate: in the form of the free base, which compound is referred to hereinafter as Compound C; and (d) tert-butyl 2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydrboxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethylcarbamate: in the form of the free base, which compound is referred to hereinafter as Compound D. The compounds of international patent application WO 01/28992 are indicated as being useful in the treatment of cardiac arrhythmias. Although general information is provided in WO 01/28992 in relation to how the compounds disclosed therein may be formulated and thereafter administered to patients, no mention is made of immediate release pharmaceutical formulations including, specifically, Compound A, B, C or D, nor salts of any of these compounds. We have found that it may be advantageous to provide Compound A, Compound B, Compound C and Compound D, and pharmaceutically-acceptable salts thereof, in an immediate release dosage form. We have further found that Compounds A, B, C and D, and salts thereof, may be readily formulated as pharmaceutical formulations, as described hereinafter, which may be stable during storage and easy to administer, e.g. for oral and parenteral administration. |
Installation for producing a spunbonded nonwoven web consolidated by fluid projection |
The invention concerns an installation for producing spunbonded nonwoven web, comprising a die designed to set filaments in a web in a deposition point on an endless conveyor and means for consolidating the web in a consolidation point downstream of the deposition point, characterized in that the consolidation means consist of a device projecting a fluid jet on the web at the consolidation point. |
1-8. (canceled) 9. An installation for producing a spunbonded nonwoven web, comprising a die arranged to deposit filaments in the form of a web onto an endless conveyor at a depositing point and means for consolidating the web at a consolidation point downstream of the depositing point, said means consisting of a projection device for projecting a jet of fluid onto the web at the consolidation point, characterized in that the consolidation point is directly downstream of the depositing point, without a consolidation device of another type interposed between the projection device and the depositing point. 10. The installation of claim 9, wherein the distance between the depositing point and the consolidation point is less than 1 meter. 11. The installation of claim 10, wherein the projection device includes outlet orifices located at a distance of 1 to 100 mm from the conveyor at the consolidation point. 12. The installation of claim 11, wherein the outlet orifices are located at a distance of 5 to 30 mm from the conveyor at the consolidation point. 13. The installation of claim 9, wherein the conveyor passes between the projection device and a suction box at the consolidation point. 14. The installation of claim 9, further including a drying device for drying the nonwoven web, downstream of the consolidation point. 15. The installation of claim 14, further including a vacuum device upstream of the drying device. 16. The installation of claim 15, wherein the fluid is water. 17. A spunbonded nonwoven web produced in the installation of claim 9. |
Propylene ethylene polymers and production process |
Ethylene propylene copolymers, substantially free of diene, are described. The copolymers will have a uniform distribution of both tacticity and comonomer between copolymer chains. Further, the copolymers will exhibit a statistically insignificant intramolecular difference of tacticity. The copolymers are made in the presence of a metallocene catalyst. |
1. A process comprising: a) polymerizing propylene and ethylene comonomers in a solution process at a reaction temperature at or above 60° C., with a polymerization catalyst complex comprising: i) an organometallic Group 4 transition metal compound; and ii) an activating cocatalyst, wherein said catalyst complex is capable of producing stereospecific polypropylene; and b) recovering a propylene copolymer containing units derived from propylene in an amount greater than or equal to 75 weight percent, and units derived from ethylene in an amount of from 5 to 25 weight percent, wherein the copolymer has a melting point of from greater than 3 5° C. to less than 110° C., and a weight average molecular weight of: Mw>6.10*P*e(3370/T) wherein: Mw=the weight average molecular weight T=the polymerization reaction temperature in degrees Kelvin P=the steady state propylene concentration in the polymerization reaction zone in moles per liter. 2. The process of claim 1 wherein said propylene copolymer contains units derived from propylene in an amount of from 80 to 90 weight percent. 3. The process of claim 1 wherein said propylene copolymer contains units derived from ethylene in an amount of from 10 to 25 weight percent. 4. The process of claim 1 wherein said homogeneous polymerization conditions are adiabatically conducted in a continuous polymerization process. 5. The process of claim 4 wherein said homogeneous polymerization conditions are conducted in a continuous process at a pressure of at least 500 bar. 6. The process of claim 1 wherein the reaction temperature is in a range of 60° C. to 200° C. 7. The process of claim 1 wherein said propylene copolymer has a melting point of from less than 90° C. to greater than 40° C. 8. The process of claim 1 wherein said propylene copolymer has a heat of fusion of greater than 1.0 J/g to less than 75 J/g. 9. The process of claim 1 wherein said propylene copolymer has a heat of fusion of greater than 4.0 J/g to less than 30 J/g. 10. The process of claim 1 wherein said organometallic Group 4 transition metal compound comprises two cyclopentadienyl ligands covalently bridged by a substituted or unsubstituted carbon atom or a substituted or unsubstituted silicon atom, wherein said Group 4 transition metal compound is chiral. 11. The process of claim 10 wherein said Group 4 metal is hafnium. 12. The process of claim 10 wherein said bridge atom is substituted with at least one methyl group. 13. The process of claim 10 wherein said cyclopentadienyl ligands are indenyl. 14. A process comprising: a) polymerizing propylene and ethylene comonomers in a solution process at a reaction temperature at or above 60° C., with a polymerization catalyst complex comprising: i) an organometallic Group 4 transition metal compound; and ii) an activating cocatalyst, wherein said catalyst complex is capable of producing stereospecific polypropylene; and b) recovering a propylene copolymer containing units derived from propylene in an amount greater than or equal to 75 weight percent, and units derived from ethylene in an amount of from 5 to 25 weight percent, wherein the copolymer has a melting point of from greater than 35° C. to less than 110° C., and a traid tacticity of greater than 85%. 15. The process of claim 14 wherein said propylene copolymer contains units derived from propylene in an amount of from 80 to 90 weight percent. 16. The process of claim 14 wherein said propylene copolymer contains units derived from ethylene in an amount of from 10 to 25 weight percent. 17. The process of claim 14 wherein said homogeneous polymerization conditions are adiabatically conducted in a continuous polymerization process. 18. The process of claim 17 wherein said homogeneous polymerization conditions are conducted in a continuous process at a pressure of at least 500 bar. 19. The process of claim 14 wherein the reaction temperature is in a range of 60° C. to 200° C. 20. The process of claim 14 wherein said propylene copolymer has a melting point of from less than 90° C. to greater than 40° C. 21. The process of claim 14 wherein said propylene copolymer has a heat of fusion of greater than 1.0 J/g to less than 75 J/g. 22. The process of claim 14 wherein said propylene copolymer has a heat of fusion of greater than 4.0 J/g to less than 30 J/g. 23. The process of claim 14 wherein said propylene copolymer has a a traid tacticity of greater than 90%. 24. The process of claim 14 wherein said organometallic Group 4 transition metal compound comprises two cyclopentadienyl ligands covalently bridged by a substituted or unsubstituted carbon atom or a substituted or unsubstituted silicon atom, wherein said Group 4 transition metal compound is chiral. 25. The process of claim 24 wherein said Group 4 metal is hafnium. 26. The process of claim 24 wherein said bridge atom is substituted with at least one methyl group. 27. The process of claim 24 wherein said cyclopentadienyl ligands are indenyl. 28. A process comprising: a) polymerizing propylene and ethylene comonomers in a solution process at a reaction temperature at or above 60° C., with a polymerization catalyst complex comprising: i) an organometallic Group 4 transition metal compound; and ii) an activating cocatalyst, precursor ionic compound comprising a halogenated tetra-aryl-substituted Group 13 anion wherein each aryl substituent contains at least two cyclic aromatic rings, wherein said catalyst complex is capable of producing stereospecific polypropylene; and b) recovering a propylene copolymer containing units derived from propylene in an amount greater than or equal to 75 weight percent, and units derived from ethylene in an amount of from 5 to 25 weight percent, wherein the copolymer has a melting point of from greater than 35° C. to less than 110° C., and a weight average molecular weight of: Mw>6.10*P*e(3370/T) wherein: Mw=the weight average molecular weight T=the polymerization reaction temperature in degrees Kelvin P=the steady state propylene concentration in the polymerization reaction zone in moles per liter. 29. The process of claim 28 wherein said propylene copolymer contains units derived from propylene in an amount of from 80 to 90 weight percent. 30. The process of claim 28 wherein said propylene copolymer contains units derived from ethylene in an amount of from 10 to 25 weight percent. 31. The process of claim 28 wherein said homogeneous polymerization conditions are adiabatically conducted in a continuous polymerization process. 32. The process of claim 31 wherein said homogeneous polymerization conditions are conducted in a continuous process at a pressure of at least 500 bar. 33. The process of claim 28 wherein the reaction temperature is in a range of 60° C. to 200° C. 34. The process of claim 28 wherein said propylene copolymer has a melting point of from less than 90° C. to greater than 40° C. 35. The process of claim 28 wherein said propylene copolymer has a heat of fusion of greater than 1.0 J/g to less than 75 J/g. 36. The process of claim 28 wherein said propylene copolymer has a heat of fusion of greater than 4.0 J/g to less than 30 J/g. 37. The process of claim 28 wherein said organometallic Group 4 transition metal compound comprises two cyclopentadienyl ligands covalently bridged by a substituted or unsubstituted carbon atom or a substituted or unsubstituted silicon atom, wherein said Group 4 transition metal compound is chiral. 38. The process of claim 37 wherein said Group 4 metal is hafnium. 39. The process of claim 37 wherein said bridge atom is substituted with at least one methyl group. 40. The process of claim 37 wherein said cyclopentadienyl ligands are indenyl. 41. The process of claim 28 wherein said organometallic Group 4 transition metal compound is selected from: μ-(CH3)2Si(indenyl)2Hf(Cl)2, μ-(CH3)2Si(indenyl)2Hf(CH3)2, μ-(CH3)2Si(tetrahydroindenyl)2Hf(Cl)2, μ-(CH3)2Si(tetrahydroindenyl)2Hf(CH3)2, μ-(CH3)2Si(indenyl)2Hf(CH2CH3)2, and μ-(C6H5)2C(indenyl)2Hf(CH3)2, 42. The process of claim 28 wherein the aryl groups of said halogenated tetraaryl Group 13 anion comprise at least one fused polycyclic aromatic ring. 43. The process of claim 28 wherein the aryl groups of said halogenated tetraaryl Group 13 anion comprises at least one aromatic ring pendant in the 4 position to a phenyl ligand. 44. The process of claim 28 wherein said halogenated tetraaryl Group 13 anion is [tetrakis(perfluoro-4-biphenyl)borate]. 45. The process of claim 28 wherein said cocatalyst precursor compound comprises an essentially cationic complex selected from anilinium, ammonium, carbenium or silylium cationic complexes. 46. A process comprising: a) polymerizing propylene and ethylene comonomers in a solution process at a reaction temperature at or above 60° C., with a polymerization catalyst complex comprising: i) an organometallic Group 4 transition metal compound; and ii) an activating cocatalyst, precursor ionic compound comprising a halogenated tetra-aryl-substituted Group 13 anion wherein each aryl substituent contains at least two cyclic aromatic rings, wherein said catalyst complex is capable of producing stereospecific polypropylene; and b) recovering a propylene copolymer containing units derived from propylene in an amount greater than or equal to 75 weight percent, and units derived from ethylene in an amount of from 5 to 25 weight percent, wherein the copolymer has a melting point of from greater than 35° C. to less than 110° C., and a triad tacticity of greater than 85%. 47. The process of claim 46 wherein said propylene copolymer contains units derived from propylene in an amount of from 80 to 90 weight percent. 48. The process of claim 46 wherein said propylene copolymer contains units derived from ethylene in an amount of from 10 to 25 weight percent. 49. The process of claim 48 wherein said homogeneous polymerization conditions are adiabatically conducted in a continuous polymerization process. 50. The process of claim 46 wherein said homogeneous polymerization conditions are conducted in a continuous process at a pressure of at least 500 bar. 51. The process of claim 46 wherein the reaction temperature is in a range of 60° C. to 200° C. 52. The process of claim 46 wherein said propylene copolymer has a melting point of from less than 90° C. to greater than 40° C. 53. The process of claim 46 wherein said propylene copolymer has a heat of fusion of greater than 1.0 J/g to less than 75 J/g. 54. The process of claim 46 wherein said propylene copolymer has a heat of fusion of greater than 4.0 J/g to less than 30 J/g. 55. The process of claim 46 wherein said propylene copolymer has a a traid tacticity of greater than 90%. 56. The process of claim 46 wherein said organometallic Group 4 transition metal compound comprises two cyclopentadienyl ligands covalently bridged by a substituted or unsubstituted carbon atom or a substituted or unsubstituted silicon atom, wherein said Group 4 transition metal compound is chiral. 57. The process of claim 56 wherein said Group 4 metal is hafnium. 58. The process of claim 56 wherein said bridge atom is substituted with at least one methyl group. 59. The process of claim 56 wherein said cyclopentadienyl ligands are indenyl. 60. The process of claim 46 wherein said organometallic Group 4 transition metal compound is selected from: μ-(CH3)2Si(indenyl)2Hf(Cl)2, μ-(CH3)2Si(indenyl)2Hf(CH3)2, μ-(CH3)2Si(tetrahydroindenyl)2Hf(Cl)2, μ-(CH3)2Si(tetrahydroindenyl)2Hf(CH3)2, μ-(CH3)2Si(indenyl)2Hf(CH2CH3)2, and μ-(C6H5)2C(indenyl)2Hf(CH3)2, 61. The process of claim 46 wherein the aryl groups of said halogenated tetraaryl Group 13 anion comprise at least one fused polycyclic aromatic ring. 62. The process of claim 46 wherein the aryl groups of said halogenated tetraaryl Group 13 anion comprises at least one aromatic ring pendant in the 4 position to a phenyl ligand. 63. The process of claim 46 wherein said halogenated tetraaryl Group 13 anion is [tetrakis(perfluoro-4-biphenyl)borate]. 64. The process of claim 46 wherein said cocatalyst precursor compound comprises an essentially cationic complex selected from anilinium, ammonium, carbenium or silylium cationic complexes. 65. A polymeric product prepared by olefin polymerization said product comprising: a) a copolymer comprising 5 to 25% by weight of ethylene-derived units and 95 to 75% by weight of propylene-derived units, the copolymer having: (i) a melting point of less than 90° C.; (ii) a relationship of elasticity to 500% tensile modulus such that Elasticity≦0.935M+12, where elasticity is in percent and M is the 500% tensile modulus in MPa; and (iii) a relationship of flexural modulus to 500% tensile modulus such that Flexural Modulus≦4.2e0.27M+50, where flexural modulus is in MPa and M is the 500% tensile modulus in MPa; and b) anions containing a single coordination complex of a charge-bearing boron or aluminum core wherein said core is tetra-aryl-substituted and each aryl substituent contains at least two cyclic aromatic rings. 66. A polymeric product prepared by olefin polymerization said product comprising: a) a copolymer comprising 5 to 25% by weight of ethylene-derived units and 95 to 75% by weight of propylene-derived units, the copolymer having: (i) a melting point of less than 90° C.; (ii) a relationship of elasticity to 500% tensile modulus such that Elasticity≦0.935M+12, where elasticity is in percent and M is the 500% tensile modulus in MPa; and (iii) a relationship of flexural modulus to 500% tensile modulus such that Flexural Modulus≦4.2e0.27M+50, where flexural modulus is in MPa and M is the 500% tensile modulus in MPa; and b) anions containing a single coordination complex of a charge-bearing boron or aluminum core wherein said core has three halogenated aryl-ligands, wherein each aryl substituent contains at least two cyclic aromatic rings, and one acetyl-aryl moiety ligand. 67-89. (canceled) |
<SOH> BACKGROUND <EOH>Ethylene propylene copolymers made with metallocene catalysts are known. Many such copolymers are intermolecularly heterogeneous in terms of tacticity, composition (weight percent comonomers) or both. Further, such polymers may also, or in the alternative, be compositionally heterogeneous within a polymer chain. Such characteristics may be, but are not always, the result of multiple reactor schemes or sequential addition of polymer. The elasticity, flexural modulus and tensile strength of such copolymers, when considered in the aggregate, may not reach a satisfactory level for use in commercial elastomeric operation. U.S. Pat. No. 5,747,621 suggests fractionable reactor blend polypropylenes, directly obtainable from the polymerization reaction of propylene having 30 to 90% by weight of a boiling n-heptane fraction, soluble in xylene at 135° C. In Table 2 of this document, the only fractionation disclosed, each of the solvents appears to be at its boiling point. Further, reference to this table shows that the diethyl-ether fraction has no melting point (amorphous). In the journal articles Science, Vol. 267, pp 217-219 (1995); Macromolecules, Vol. 31, pp 6908-6916 (1998); and Macromolecules, Vol. 32, pp 8283-8290, pp 3334-3340 and pp 8100-8106, propylene polymers with similar characteristics as those disclosed in the above discussed U.S. Pat. No. 5,747,621 are made and fractionated. The polymers are made with bis(aryl indenyl) or bisindenyl metallocene catalysts. In these journal articles, these polymers are fractionated in boiling ether and heptane, leaving a portion of the polymer insoluble in either. The polypropylenes are stated to be compositionally heterogeneous in terms of tacticity and molecular weight. U.S. Pat. No. 5,504,172 suggests a propylene elastomer that has properties such that: (a) the elastomer contains propylene units in an amount of 50 to 95% by mol and ethylene units in an amount of 5 to 50 % by mol; (b) a triad tacticity of three propylene units-chains consisting of head-to-tail bonds, as measured by 13 C NMR, is not less than 90.0%; and (c) a proportion of inversely inserted propylene units based on the 2,1-insertion of a propylene monomer in all propylene insertions, as measured by 13 C NMR, is not less than 0.5%, and a proportion of inversely inserted propylene units based on the 1,3-insertion of a propylene monomer, as measured by 13 C NMR, is not more than 0.05%. U.S. Pat. No. 5,391,629 suggests block and tapered copolymers of ethylene with an α-olefin. The copolymers are made by a process of sequentially contacting ethylene with an α-olefin monomer in the presence of an activated cyclopentadienyl catalyst system. EP 0 374 695 suggests ethylene-propylene copolymers and a process for preparing them. The copolymers have a reactivity ratio product, r 1 r 2 , between 0.5 and 1.5 and an isotactic index greater than 0 percent. The copolymers are produced in the presence of a homogeneous chiral catalyst and an alumoxane co-catalyst. There is a commercial need therefore for an ethylene propylene copolymer that will show a melting point and an excellent balance of elasticity, flexural modulus and tensile strength. It would further be desirable if such polymers could be produced at higher polymerization temperatures. It is known that temperature affects the polymerization involving the stereo regular polymerization of alpha-olefins, in particular propylene. Under similar polymerization conditions the increase in the polymerization temperatures leads to both a drop in molecular weight as well as a loss in the tacticity of the alpha olefin residues along the chain. This effect exists for both the homopolymerization of the 1-olefins as well as copolymerization of 1-olefins with ethylene, or other alpha-olefins. These changes in the characteristic of the polymer are detrimental to certain end uses of the polyolefin. However, there are commercial incentives in raising the polymerization temperature since this improves the throughput of the polymerization reactor. This would necessarily lead to better economics for production for these polymers if physical attributes of the polymer product, such as tacticity and molecular weight, could meet or exceed the properties now achieved at lower temperatures. |
<SOH> SUMMARY <EOH>We have discovered that ethylene-propylene copolymers, when produced in the presence of a metallocene catalyst and an activator, in a single steady state reactor, show a surprising and unexpected balance of flexural modulus, tensile strength and elasticity. Moreover, these and other properties of the copolymers show surprising differences relative to conventional polymer blends, such as blends of isotactic polypropylene and ethylene-propylene copolymers. In one embodiment, the copolymer includes from a lower limit of 5% or 6% or 8% or 10% by weight to an upper limit of 20% or 25% by weight ethylene-derived units, and from a lower limit of 75% or 80% by weight to an upper limit of 95% or 94% or 92% or 90% by weight propylene-derived units, the percentages by weight based on the total weight of propylene- and ethylene-derived units. The copolymer is substantially free of diene-derived units. In various embodiments, features of the copolymers include some or all of the following characteristics, where ranges from any recited upper limit to any recited lower limit are contemplated: (i) a melting point ranging from an upper limit of less than 110° C., or less than 90° C., or less than 80° C., or less than 70° C., to a lower limit of greater than 25° C., or greater than 35° C., or greater than 40° C., or greater than 45° C.; (ii) a relationship of elasticity to 500% tensile modulus such that Elasticity≦0.935 M+ 12, or Elasticity≦0.935 M+ 6, or Elasticity≦0.935 M, where elasticity is in percent and M is the 500% tensile modulus in megapascal (MPa); (iii) a relationship of flexural modulus to 500% tensile modulus such that in-line-formulae description="In-line Formulae" end="lead"? Flexural Modulus≦4.2 e 0.27M +50, or in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? Flexural Modulus≦4.2 e 0.27M +30, or in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? Flexural Modulus≦4.2 e 0.27M +10, or in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? Flexural Modulus≦4.2 e 0.27M +2, in-line-formulae description="In-line Formulae" end="tail"? where flexural modulus is in MPa and M is the 500% tensile modulus in MPa; (iv) a heat of fusion ranging from a lower limit of greater than 1.0 joule per gram (J/g), or greater than 1.5 J/g, or greater than 4.0 J/g, or greater than 6.0 J/g, or greater than 7:0 J/g, to an upper limit of less than 125 J/g, or less than 100 J/g, or less than 75 J/g, or less than 60 J/g, or less than 50 J/g, or less than 40 J/g, or less than 30 J/g;. (v) a triad tacticity as determined by carbon-13 nuclear magnetic resonance ( 13 C NMR) of greater than 75%, or greater than 80%, or greater than 85%, or greater than 90%; (vi) a tacticity index m/r ranging from a lower limit of 4 or 6 to an upper limit of 8 or 10 or 12; (vii) a proportion of inversely inserted propylene units based on 2,1 insertion of propylene monomer in all propylene insertions, as measured by 13 C NMR, of greater than 0.5% or greater than 0.6%; (viii) a proportion of inversely inserted propylene units based on 1,3 insertion of propylene monomer in all propylene insertions, as measured by 13 C NMR, of greater than 0.05%, or greater than 0.06%, or greater than 0.07%, or greater than 0.08%, or greater than 0.085%; (ix) an intermolecular tacticity such that at least X % by weight of the copolymer is soluble in two adjacent temperature fractions of a thermal fractionation carried out in hexane in 8° C. increments, where X is 75, or 80, or 85, or 90, or 95, or 97, or 99; (x) a reactivity ratio product r 1 r 2 of less than 1.5, or less than 1.3, or less than 1.0, or less than 0.8; (xi) a molecular weight distribution Mw/Mn ranging from a lower limit of 1.5 or 1.8 to an upper limit of 40 or 20 or 10 or 5 or 3; (xii) a molecular weight of from 15,000-5,000,000; (xiii) a solid state proton nuclear magnetic resonance ( 1 H NMR) relaxation time of less than 18 milliseconds (ms), or less than 16 ms, or less than 14 ms, or less than 12 ms, or less than 10 ms; (xiv) an elasticity as defined herein of less than 30%, or less than 20%, or less than 10%, or less than 8%, or less than 5%; and (xv) a 500% tensile modulus of greater than 0.5 MPa, or greater than 0.8 MPa, or greater than 1.0 MPa, or greater than 2.0 MPa. The copolymer be made in the presence of a bridged metallocene catalyst, in a single steady-state reactor. Thus, in another aspect, the present invention is directed to a process for producing an ethylene-propylene copolymer having some or all of the above-recited characteristics, by reacting ethylene and propylene in a steady-state reactor under reactive conditions and in the presence of a bridged metallocene catalyst. In another embodiment, the invention comprises a solution polymerization process for making the above described semicrystalline ethylene propylene copolymers by using particular catalyst and activator combination that lead to similar molecular weights and crystallinity from polymerization at a higher temperature or alternatively higher molecular weight and/or crystallinity when compared to polymerization processes conducted at a lower temperature using previous catalyst and activator combinations. This embodiment involves the use of bulky, non-coordinating activators in conjunction with single sited metallocene catalysts capable of making the polymers described above. In another aspect, this embodiment can additionally operate using a higher concentration of the monomers present in the polymerization reactor during polymerization. The combination of these two components of the invention leads to copolymers which have both a higher molecular weight as well as a higher level of tacticity of the propylene residues. Thus these bulky activator systems and higher monomer concentrations can be used for the polymerization of these copolymers at higher temperatures compared to the polymerization conducted with smaller anions while still generating copolymers which have similar molecular weights and isotactic propylene crystallinity. |
Prefillable intradermal delivery device with hidden needle and passive shielding |
An intradermal needle assembly (10) for injecting a substance into the skin of an animal is disclosed. A hub (16) is attachable to a container (12) storing the substance. A needle (18) is supported by the hub (16) and has a forward tip (20) extending away from the hub (16). A limiter (22) surrounds the needle (18) and extends away from the hub (16) toward the forward tip (20) of the needle (18). The limiter (22) includes a generally flat skin engaging surface (24) extending in a plane generally perpendicular to an axis of the needle (18) and is adapted to be received against the skin (26) to administer an intradermal injection. The limiter (22) is movable between a first position (28), wherein the skin engaging surface (24) shields the needle (18), and a second position (30), wherein the forward tip (20) extends beyond the skin (26) upon depressing the skin engaging surface (24) against the skin (26). |
1. An intradermal needle assembly for use with a prefillable container having a reservoir capable of storing a substance for injection into the skin of an animal comprising: a hub portion being attachable to the prefillable container; a needle cannula supported by said hub portion and having a forward tip extending away from said hub portion; and a limiter surrounding said needle cannula and extending away from said hub portion toward said forward tip of said needle cannula, said limiter including a generally flat skin engaging surface extending in a plane generally perpendicular to an axis of said needle cannula and adapted to be received against the skin of the animal to administer an intradermal injection of the substance; said limiter being movable between at least a first position, wherein said skin engaging surface shields said forward tip of said needle cannula, and a second position, wherein said forward tip extends beyond said skin engaging surface a distance sufficient to administer the substance into the dermis layer of the animal upon depression of said skin engaging surface against the skin of the animal. 2. An assembly as set forth in claim 1, further comprising spring means for biasing said limiter towards said first position. 3. An assembly as set forth in claim 1, wherein said forward tip of said needle cannula extends beyond said skin engaging surface a distance ranging from approximately 0.5 mm to 3.0 mm when said limiter is located in said second position thereby limiting penetration of said needle into the dermis layer of skin of the animal so that the substance is injected into the dermis layer of the animal. 4. An assembly as set forth in claim 3, further comprising a sleeve having the prefillable container fixedly disposed therein with said limiter slideably protruding therefrom. 5. An assembly as set forth in claim 4, wherein said sleeve includes a stop positioned to prevent said limiter from sliding beyond said second position. 6. An assembly as set forth in claim 1, further comprising catch engageable to prevent said limiter from moving from said first position to said second position subsequent to administering the intradermal injection. 7. An assembly as set forth in claim 1, wherein the prefillable container includes a rim disposed on an end opposite said hub and said spring means is provided between said rim and said limiter. 8. An assembly as set forth in claim 2, wherein said spring means is provided between said hub and said limiter thereby biasing said limiter towards said first position. 9. An assembly as set forth in claim 8, further comprising a stop positioned to prevent said limiter from sliding beyond said second position. 10. An assembly as set forth in claim 9, wherein said hub includes a catch engageable with said limiter when said limiter is returned to said first position thereby preventing said limiter from moving from said first position to said second position subsequent to administering the intradermal injection. 11. An assembly as set forth in claim 1, further comprising a plug comprising a resilient material applied over said forward tip of said needle cannula thereby sealing said prefillable container at said needle cannula. 12. An intradermal needle assembly for use with a prefillable container having a reservoir capable of storing a substance for injection into the skin of an animal comprising: a hub portion being attachable to the prefillable container; a needle cannula supported by said hub portion and having a forward tip extending away from said hub portion; a limiter portion surrounding said needle cannula and extending away from said hub portion toward said forward tip of said needle cannula, said limiter including a generally flat skin engaging surface extending in a plane generally perpendicular to an axis of said needle cannula and adapted to be received against the skin of the animal to administer an intradermal injection of the substance, said needle forward tip extending beyond said skin engaging surface a distance sufficient to enable injection of the substance into the dermis layer of the animal; and a shield circumscribing said limiter and being biased towards said forward tip of said needle cannula with at least a first position wherein said shield shields said forward tip, and a second position wherein said shield exposes said forward tip. 13. An assembly as set forth in claim 12, wherein said needle cannula extends beyond said skin engaging surface a distance ranging from approximately 0.5 mm to 3.0 mm. 14. An assembly as set forth in claim 13, further comprising a sleeve having the prefillable container fixedly disposed therein with said shield slideably protruding therefrom. 15. An assembly as set forth in claim 12, further comprising a spring means disposed within said sleeve and biasing said shield towards said forward tip of said needle cannula. 16. An assembly as set forth in claim 15, wherein the prefillable container includes a rim disposed on an end opposite from said hub whereby said spring means is compressed between said rim and said shield. 17. An assembly as set forth in claim 12, wherein said shield is moveable between said first position and said second position by depressing said skin engaging surface against the skin of the animal. 18. An assembly as set forth in claim 12, wherein said sleeve includes a stop positioned to prevent said limiter from sliding beyond said second position. 19. An assembly as set forth in claim 18, further comprising a catch engageable when said shield is returned to said first position thereby preventing said shield from moving from said first position to said second position subsequent to administering the intradermal injection. 20. An assembly as set forth in claim 12, further comprising a plug comprising a resilient material applied over said forward tip of said needle cannula thereby sealing said prefillable container at said needle cannula. 21. A method of administering an intradermal injection into the skin of an animal comprising the steps of: providing a drug delivery device including a needle cannula having a forward needle tip, said needle cannula being in fluid communication with a substance contained in said drug delivery device; shielding said forward tip of said needle cannula with a shielding surface by locating said shielding surface in a first position; depressing said shielding surface against the skin of an animal thereby moving said shielding surface to a second position and exposing said forward tip of said needle cannula a length sufficient to administer an intradermal injection; inserting said forward tip into the skin of the animal and engaging the surface of the skin with said skin engaging shielding surface such that said shielding surface limits penetration of the forward tip into the dermis layer of the skin of the animal; expelling the substance from said drug delivery device through said forward tip into the dermis of the animal; and retracting said shielding surface from the skin of the animal thereby allowing said shielding surface to move from said second position to said first position thereby shielding said forward tip of said needle cannula. 22. A method as set forth in claim 21 wherein said step of exposing said forward tip of said needle cannula is further defined as exposing a length of said needle cannula equal to approximately 0.5 mm to approximately 3.0 mm. 23. A method as set forth in claim 21 wherein said shielding surface is further defined as having a fixed angle of orientation relative to said needle cannula. 24. A method as set forth in claim 21 wherein said shielding surface is further defined as being adapted to be received against the skin of an animal. 25. A method as set forth in claim 21 further including the step of securing said shielding surface in said first position subsequent to expelling the substance from said drug delivery device into the dermis of the animal to prevent said forward tip of said needle cannula from being re-exposed. 26. A method as set forth in claim 21 further including the step of biasing said shielding surface towards said first position. 27. A method as set forth in claim 21 further including the step of providing a plunger being slideably disposed with said prefillable container and being depressible for expelling the substance from the container. 28. A method as set forth in claim 21 further including the step of unsealing said needle cannula prior to depressing said shielding surface against the skin of the animal. 29. An intradermal needle assembly for a prefillable container having a reservoir capable of storing a substance for injection into the skin of an animal comprising: a hub portion provided on the prefillable container; a needle cannula supported by said hub portion and having a forward tip extending away from said hub portion; and a limiter surrounding said needle cannula and extending away from said hub portion toward said forward tip of said needle cannula, said limiter including a generally flat skin engaging surface extending in a plane generally perpendicular to an axis of said needle cannula, said limiter being movable between a first position in which said forward tip of said needle cannula is contained within said limiter, and a second position in which said forward tip of said needle cannula extends beyond said skin engaging surface a distance sufficient to administer the substance into the dermis layer of the animal upon depression of said skin engaging surface against the skin of the animal. 30. An assembly as set forth in claim 29, further comprising spring means for biasing said limiter toward said first position. 31. An assembly as set forth in claim 29, wherein said forward tip of said needle cannula extends beyond said skin engaging surface a distance ranging from approximately 0.5 mm to 3.0 mm when said limiter is located in said second position thereby limiting penetration of said needle into the dermis layer of skin of the animal so that the substance is injected into the dermis layer of the animal. 32. An assembly as set forth in claim 31, further comprising a sleeve having the prefillable container fixedly disposed therein with said limiter slideably protruding therefrom. 33. An assembly as set forth in claim 32, wherein said sleeve includes a stop positioned to prevent said limiter from sliding beyond said second position. 34. An assembly as set forth in claim 29, further comprising a catch engageable to prevent movement of said limiter from said first position to said second position subsequent to administering the intradermal injection. 35. An assembly as set forth in claim 29, wherein the prefillable container includes a rim disposed on an end opposite said hub and wherein said spring means is provided between said rim and said limiter. 36. An assembly as set forth in claim 30, wherein said spring means is provided between said hub and said limiter thereby biasing said limiter towards said first position. 37. An assembly as set forth in claim 36, further comprising a stop positioned to prevent said limiter from moving beyond said second position. 38. An assembly as set forth in claim 37, wherein said hub includes a catch engageable with said limiter when said limiter is returned to said first position thereby preventing said limiter from moving from said first position to said second position subsequent to administering the intradermal injection. 39. An assembly as set forth in claim 29, further comprising a plug comprising a resilient material applied over said forward tip of said needle cannula thereby sealing said prefillable container at said needle cannula. 40. An intradermal needle assembly for a prefillable container having a reservoir capable of storing a substance for injection into the skin of an animal comprising: a hub portion provided on the prefillable container; a needle cannula supported by said hub portion and having a forward tip extending away from said hub portion; a limiter portion surrounding said needle cannula and extending away from said hub portion toward said forward tip of said needle cannula, said limiter including a generally flat skin engaging surface extending in a plane generally perpendicular to an axis of said needle cannula, said needle forward tip extending beyond said skin engaging surface a distance sufficient to enable injection of the substance into the dermis layer of the animal; and a shield circumscribing said limiter and being movable between a first position, in which said forward tip of said needle cannula is shielded by said shield, and a second position, in which said forward tip of said needle cannula is exposed, said shield being biased towards said a first position. 41. An assembly as set forth in claim 40, wherein said needle cannula extends beyond said skin engaging surface a distance ranging from approximately 0.5 mm to 3.0 mm. 42. An assembly as set forth in claim 41, further comprising a sleeve having the prefillable container fixedly disposed therein with said shield slideably protruding therefrom. 43. An assembly as set forth in claim 40, further comprising a spring means disposed within said sleeve and biasing said shield towards said forward tip of said needle cannula. 44. An assembly as set forth in claim 43, wherein the prefillable container includes a rim disposed on an end opposite from said hub whereby said spring means is compressed between said rim and said shield. 45. An assembly as set forth in claim 40, wherein said shield is moveable between said first position and said second position by depressing said skin engaging surface against the skin of the animal. 46. An assembly as set forth in claim 40, wherein said sleeve includes a stop positioned to prevent said limiter from sliding beyond said second position. 47. An assembly as set forth in claim 46, further comprising a catch engageable when said shield is returned to said first position thereby preventing said shield from moving from said first position to said second position subsequent to administering the intradermal injection. 48. An assembly as set forth in claim 40, further comprising a plug comprising a resilient material applied over said forward tip of said needle cannula thereby sealing said prefillable container at said needle cannula. 49. An assembly as set forth in claim 1, further comprising a prefillable container. 50. An assembly as set forth in claim 12, further comprising a prefillable container. 51. An assembly as set forth in claim 29, further comprising a prefillable container. 52. An assembly as set forth in claim 40, further comprising a prefillable container. |
<SOH> BACKGROUND OF THE INVENTION <EOH>Intradermal injections are used for delivering a variety of substances. Many of these substances have proven to be more effectively absorbed into or react with the immune response system of the body when injected intradermally. An intradermal injection is made by delivering the substance into the epidermis and upper layer of the dermis. Below the dermis layer is subcutaneous tissue (also sometimes referred to as the hypodermis layer) and muscle tissue, in that order. There is considerable variation in the skin thickness both between individuals and within the same individual at different sites of the body. Generally, the outer skin layer epidermis has a thickness of between 50 to 200 microns, and the dermis, the inner and thicker layer of the skin, has a thickness between 1.5 and 3.5 mm. Therefore, a needle cannula that penetrates the skin deeper than about 3.0 mm has a potential of passing through the dermis layer of the skin making the injection into the subcutaneous region, which may result in an insufficient immune response, especially where the substance to be delivered intradermally has not been indicated for subcutaneous injection. Also, the needle cannula may penetrate the skin at too shallow a depth to deliver the substance and result in what is commonly known in the art as “wet injection” due to reflux of the substance from the injection site. Due to the inherent limitations of the standard needle assembly, the standard procedure for making an intradermal injection is known to be difficult to perform, and therefore dependent upon experience and technique. This procedure is recommended to be performed by stretching the skin, orienting the needle bevel to face upwardly, and inserting a 26 gauge short bevel needle cannula to deliver a volume of 0.5 ml or less of the substance into the skin of the animal with the needle cannula being inserted into the skin at an angle varying from around 10 to 15° to form a blister or wheel in which the substance is deposited or otherwise contained. The technique utilized to perform the standard intradermal injection is difficult and requires the attention of a trained nurse or medical doctor. Inserting the needle to a depth greater than about 3.0 mm typically results in a failed intradermal injection because the substance being expelled through the cannula will be injected into the subcutaneous tissue of the animal. As disclosed in pending U.S. patent application Ser. Nos. 09/834,438 and 09/417,671, an intradermal needle assembly has been developed for use with a prefillable container having a reservoir capable of storing a substance for injection into the skin of an animal. A hub portion, which is attachable to the prefillable container storing the substance, supports a needle cannula having a forward tip extending away from the hub portion. A limiter portion surrounds the needle cannula and extends away from the hub portion towards the forward tip of the needle cannula. The limiter includes a generally flat skin engaging surface extending in a plane generally perpendicular to an axis of the needle cannula and is adapted to be received against the skin of the animal to administer the intradermal injection of the substance. The needle forward tip extends beyond the skin engaging surface a distance of approximately 0.5 to 3.0 mm. Therefore, the limiter portion limits penetration of the needle into the dermis layer of the skin of the animal so that the vaccine is injected into the dermis layer of the animal. The devices that have been adapted to administer an intradermal injection, and other devices utilizing needle cannulas with sharp tips to inject substances into the skin of the animal have typically included a fixed design where each of the components of the assembly are stationary relative to the other components. Therefore, the forward tip of the needle cannula remains exposed even after administration of the intradermal injection. With the advent of viral diseases transmitted through the contact of body fluid, it has become desirable to develop needle shielding devices that would prevent unintended access to the needle cannula subsequent to administering an injection. While these types of devices have been introduced to the marketplace for standard injection assemblies, they have not been developed in combination with an injection device adapted to administer an intradermal injection through the use of a limiter as described above. In addition, it has become increasingly desirable to hide the needle prior to use to address any potential concerns by patients of seeing an exposed needle prior to use. Therefore, it would be desirable to introduce an intradermal delivery assembly utilizing a limiter, as set forth above, to limit the penetration of a needle cannula into the dermis of an animal in combination with a shielding component to prevent unintended contact with the needle subsequent to administration of the intradermal injection, and to hide the needle prior to use. |
<SOH> SUMMARY OF THE INVENTION AND ADVANTAGES <EOH>In contrast to the intradermal injection assemblies that have been disclosed in the past, it has been determined by the Applicant that it is feasible to include a shielding device with the intradermal assembly that can provide the benefit of shielding the forward tip of the needle cannula both prior to and subsequent to administering an intradermal injection. The intradermal needle assembly of the present invention is for use with a prefillable container that includes a reservoir capable of storing a substance for injection into the skin of an animal. A hub portion is attachable to the prefillable container storing the substance and supports a needle cannula. The needle cannula includes a forward tip extending away from the hub portion. A limiter surrounds the needle cannula and extends away from the hub portion towards the forward tip of the needle cannula. The limiter includes a generally flat skin engaging surface extending in a plane generally perpendicular to an axis of the needle cannula and is adapted to be received against the skin of the animal to administer an intradermal injection of the substance. The limiter is moveable between at least a first position where the skin engaging surface shields the forward tip of the needle cannula, and a second position where the forward tip extends beyond the skin engaging surface a distance sufficient to administer the substance into the dermis layer of the animal upon depression of the skin engaging surface against the skin of the animal. The limiter is biased toward the first position by a spring means that is compressible upon depressing the skin engaging surface against the skin of the animal. Therefore, after administering the intradermal injection and withdrawing the skin engaging surface from the skin of the animal, the limiter returns and locks to the first position to shield the forward tip of the needle cannula. Alternatively, the limiter is circumscribed by a shield that is biased toward the forward tip of the needle cannula by the spring means. In this embodiment, the shield is moveable between the first position where the forward tip of the needle cannula is shielded, and the second position where the forward tip of the needle cannula extends beyond the skin engaging surface a distance sufficient to administer the substance into the dermis layer of the animal upon depression of the skin engaging surface against the skin of the animal. Accordingly, the limiter is fixed relative to the needle cannula and the hub portion and only the shield is moveable between the first and second positions. The embodiments of the subject invention set forth above provide the benefit of administering an intradermal injection utilizing a depth limiting device that limits the penetration of the forward tip of the needle cannula into the dermis layer of the animal simplifying the method of administering the intradermal injection. Further, a passive shielding device is provided which shields the forward tip of the needle cannula both prior to and subsequent to administering the intradermal injection. Thus, the intradermal needle assembly prevents exposure to the forward tip of the needle cannula prior to administering the injection maintaining sterilization, and subsequent to administering the injection reducing the potential for a biohazard resulting from contact with the needle cannula. |
Leg device for leg type movable robot, and method of controlling leg type movable robot |
In a foot of a legged mobile robot, deformation of the foot is absorbed by a first concavity and the position and shape of a ground-contact portion hardly change. Accordingly, variation in a resistive force against the moment about the yaw axis can be reduced and a spinning motion can be prevented. In addition, when the foot is placed on a bump or a step, a flexible portion deforms and receives it, and a frictional retaining force is generated between the flexible portion and the bump. Thus, the foot is flexibly adapted to the road surface, and sliding caused by the bump and excessively fast motion are prevented. Accordingly, the foot can be adapted to various kinds of road surfaces such as surfaces having bumps and depressions, and the attitude stability can be increased. |
1. A leg device of a legged mobile robot having a plurality of movable legs, comprising: a foot sole having a foot bottom surface and side surfaces which extend continuously from the periphery of the foot bottom surface; and a first concavity having a slope which slopes toward the inside of the foot bottom surface. 2. A leg device of a legged mobile robot according to claim 1, wherein the ground-contact portion is disposed at each of four comers of the foot bottom surface. 3. A leg device of a legged mobile robot according to claim 1, further comprising a flexible portion disposed in the first concavity, the flexible portion being composed of a material having a predetermined elasticity. 4. A leg device of a legged mobile robot according to claim 1, further comprising a second concavity in the first concavity, the second concavity being deeper than the slope of the first concavity. 5. A leg device of a legged mobile robot according to claim 4, wherein the flexible portion is disposed in the second concavity. 6. A leg device of a legged mobile robot according to claim 1, further comprising one or more grooves, each groove being formed in a ground-contact surface of the foot such that the groove extends from the first concavity across a peripheral portion of the foot and communicates with the outside through one of the side surfaces of the foot. 7. A leg device of a legged mobile robot according to claim 1, comprising: an instep attached to the corresponding movable leg; and a foot sole attached to the instep such that the foot sole can move along a plane parallel to the foot bottom surface. 8. A leg device of a legged mobile robot according to claim 1, comprising: a main foot body which is detachably attached to an end portion of the corresponding movable leg; and memory means which is provided on the main foot body and which stores information related to the main foot body. 9. A leg device of a legged mobile robot according to claim 1, comprising: an instep which is retained by the corresponding movable leg at an ankle of the corresponding movable leg; a foot sole detachably attached to the instep; and memory means which is provided on the foot sole and which stores information related to the foot and/or control means which controls motion of the corresponding movable leg on the basis of the information stored in the memory means. 10. A leg device of a legged mobile robot according to claim 1, comprising: a main foot body which is retained by the corresponding movable leg at an ankle of the corresponding movable leg; memory means which is provided on the main foot body and which stores information related to the main foot body and/or control means which controls motion of the corresponding movable leg on the basis of the information stored in the memory means; and an opening through which the memory means and/or the control means face outside so that the memory means and/or the control means can be replaced. 11. A leg device of a legged mobile robot according to claim 9, wherein the control means reads out the information stored in the memory means at the time of initialization. 12. A method for controlling a legged mobile robot having a foot which is detachably attached to an end portion of a movable leg, the method comprising the steps of: storing information related to the foot in memory means provided on the foot; reading out the information from the memory means at the time of initialization; and controlling motion of the movable leg on the basis of the information read out. 13. A leg device of a legged mobile robot according to claim 10, wherein the control means reads out the information stored in the memory means at the time of initialization. |
<SOH> BACKGROUND ART <EOH>In recent years, progress has been made in the research and development of legged mobile robots modeled after animals which walk upright on two feet, such as human beings and apes, and they are increasingly expected to be used for practical purposes. The legged mobile robots which walk upright on two feet are unstable compared to crawler-type, four-legged, and six-legged robots, and have a disadvantage in that attitude control and walking control thereof are complex. However, they are advantageous in that they can flexibly adapt themselves to places with severe conditions, for example, places where an operational area includes bumps and depressions as in rough terrains and places with obstacles, discontinuous walking surfaces such as stairs and ladders, etc., and perform locomotion. Most workspaces and living spaces of human beings are designed in accordance with their body mechanisms and behavioral patterns that they walk upright on two feet. As a result, there are so many barriers for present mechanical systems using wheels or other driving devices as moving means to move in living spaces of human beings. In order for mechanical systems, that is, robots, to help people with various human tasks or carry out the tasks in place of people and to come into widespread use in people's living spaces, moving areas of the robots are preferably the same as those of people. This is the reason why there are great expectations of putting the legged mobile robots to practical use. In order to enhance the adaptability of robots to people's living environments, it is necessary that they have a construction similar to that of human beings. Various techniques have been proposed with respect to attitude control and stable walking of the legged mobile robots which walk on two feet, and many of them use a zero moment point (ZMP) as a criterion for stability evaluation of walking motion. The stability evaluation using the ZMP is based on d'Alembert's principle that a gravity force, an inertial force, and a moment thereof are applied by a walking system to a road surface and this moment is balanced with a ground reaction force and a ground reaction moment which are applied to the walking system as a reaction from the road surface. As a result of mechanical inference, a point where moments about a pitch axis and a roll axis are zero exists in a support polygon formed by contact points between the bottom surface of a foot and the road surface or on the sides of the support polygon, and this point is called the ZMP. Biped walking control using the ZMP as a criterion has an advantage in that positions at which each foot hits the road surface can be determined in advance and kinematic constraints on a toe portion of each foot corresponding to the shape of the road surface can be easily taken into account. In addition, when the ZMP is used as a criterion for the stability evaluation, a trajectory, instead of a force, is used as a target of motion control, and therefore, there is higher technical feasibility. The concept of the ZMP and the application thereof as a criterion for the stability evaluation of a walking robot are described in “Legged Locomotion Robots” written by Miomir kobratovic (“Walking Robots and Artificial Legs” written by Ichiro Kato et al., published by The Nikkan Kogyo Shinbun, Ltd.). The stability and controllability of the legged mobile robots during legged motion are affected not only by moving patterns of four limbs but also by the state of a road surface (ground surface or floor surface) on which they perform the legged motion, such as walking. This is because as long as a foot is placed on the road surface, it constantly receives the reaction force from the road surface. Accordingly, the structure of the foot which directly receives the reaction force from the road surface is extremely important in view of the stability and controllability of the legged mobile robots during the legged motion, and various proposals have been made. For example, a structure is known in which an elastic sheet composed of rubber or the like is adhered to the foot bottom surface in order to reduce an impact which occurs when an idling leg (one of the legs which is separated from the road surface) is placed on the road surface, that is, an impact in a Z-axis direction (direction perpendicular to the foot bottom surface or direction which extends along a yaw axis). In addition, a structure in which a metal plate is adhered to the bottom surface of the elastic sheet in order to prevent the breakage and deformation of the elastic sheet is also known in the art. In addition, a structure in which a metal plate is provided on the foot bottom surface with a leaf spring therebetween in order to absorb the impact in the Z-axis direction and a structure in which a rubber material is applied to the foot bottom surface in order to prevent slipping on the road surface are also known in the art. However, most of the above-described known foot structures are obtained by making improvements for reducing the impact from the road surface when the foot hits the road surface or preventing slipping on the road surface, and the basic shape thereof is not changed from a plate-like shape, as shown in FIG. 82 (A). When a foot 920 shown in FIG. 82 is placed on a road surface 911 , the entire region of the foot bottom surface is in contact with the road surface 911 . In this known foot, when the ZMP is at the central position of the foot 910 , as shown in FIG. 82 (B), load of the robot may concentrate at this point and the foot 910 may deflect away from the road surface 911 and change the shape thereof. In such a case, there is a problem in that the contact area between the foot 910 and the road surface 911 decreases and the resistive force against the moment around the yaw axis also decreases. In addition, the shape of a contact surface between the foot sole and the road surface changes along with the change in the shape of the foot, and this leads to the change in dynamic characteristics of the legged mobile robot. As a result, the attitude of the robot becomes unstable. The reduction in the attitude stability is not only caused by the deflection of the foot sole. Also in the case in which a bump is positioned under the central area of the foot bottom surface when the foot sole is placed on the road surface, the foot falls into a so-called seesaw state and a similar problem occurs. In addition, since no consideration is made on the corners and side edges of the foot bottom surface, that is, a ground-contact surface of the foot sole, if the road surface has bumps and depressions, the corners and side edges may interfere with the road surface with bumps and depressions when the idling leg is placed thereon, and this may cause the robot to stumble. In addition, the robot may fall into a so-called stick-slip state where the robot repeatedly stumbles and recovers. As a result, the upper body of the robot may loose balance and the attitude of the robot may become unstable. As an index of stability of the robot's attitude, a concept referred to herein as “resistive-force-generation effective surface” is used. When there is only one ground-contact surface between the foot and the road surface, this surface is defined as the resistive-force-generation effective surface. In addition, when the foot is in point contact with the road surface, as shown in FIG. 83 , a plane which is surrounded by lines which connect every two adjacent points is defined as the resistive-force-generation effective surface. In addition, when a ground-contact portion of the foot is frame-shaped, as shown in FIG. 84 , a surface surrounded by the sides of the frame is defined as the resistive-force-generation effective surface. More specifically, the “resistive-force-generation effective surface” corresponds to a surface obtained by connecting the points where the resistive force against the moment about the yaw axis generated in the legged mobile robot is applied by the road surface. When the ZMP moves as the legged mobile robot walks, the foot deforms and the area of the resistive-force-generation effective surface decreases. Accordingly, the resistance against the moment about the yaw axis generated due to the motion of the legged mobile robot decreases and the attitude of the legged mobile robot becomes unstable. As a result, spinning motion may occur. In addition, the change in the shape of the resistive-force-generation effective surface may cause an unexpected change in the behavior of the legged mobile robot, which leads to the reduction in the attitude stability of the legged mobile robot. Accordingly, in the foot bottom surface of the legged mobile robot, both the static and dynamic adjustments of the surface pressure applied to the ground-contact surface are necessary. In other words, not only a pressure value but also the variation and distribution thereof must be adjusted. In addition, similarly, both the static and dynamic adjustments of friction are necessary. These problems can be solved if the walking surface is limited to mainly flat surfaces or smooth, continuous surfaces. However, it is to be noted that the actual walking surfaces include continuous, swelling surfaces and discontinuous surfaces such as surfaces with bumps and depressions or steps, and these surfaces are also the cause of the reduction in the attitude stability of the legged mobile robots. More specifically, when a foot is placed on a step, as shown in FIG. 85 , the foot totters and support moment cannot be generated at a ground-contact portion. As a result, the behavior of the foot becomes nonlinear and its control becomes extremely difficult. In addition, the motion trajectory becomes unstable, and correction control and a movement plan must be reset. In addition, when the foot is placed on a delicate, slippery surface, such as a carpet, as shown in FIG. 86 , there is a high possibility that the ground-contact surface of the foot will slip and the motion stability of the legged mobile robot will decrease considerably. In addition, when the foot is placed on a surface with high friction or a soft surface which easily catches the foot, as shown in FIG. 87 , falling moment is generated due to the inertial force, etc., when the surface pressure, which depends on the shape of the ground-contact surface of the foot, or friction in the planar direction excessively increases. Therefore, it is necessary to adjust the frictional characteristics of the ground-contact portion. In addition, when the foot is placed on a step, as shown in FIG. 88 , in addition to the problem of the support moment described above with reference to FIG. 85 , there is also a problem in that the foot may slide down when conditions of the shape of the step, or a bump, are not good or when the friction is extremely low. In addition, since such a motion is extremely fast compared to control cycles, there is a risk that suitable countermeasures cannot be implemented. In such a case, as shown in FIG. 89 , a structure like a plantar arch, for example, may be formed in the foot so as to avoid the edge of the step. However, in this structure, the plantar arch comes into contact with the edge of the step or the bump such that a resistive-force-generation effective surface 921 has a triangular shape, as shown by the hatched area in the figure, and conditions for ensuring the stability become severe. The motion performance and the stability must also be ensured on the steps. In addition, with respect to biped walking robots, there is always a possibility of falling over, which must be avoided as much as possible. In order to avoid falling over, the development of control methods is carried out in view of how to avoid the disturbance of the balance and achieve stable motion and how to recover after losing the balance. In addition to the development of control methods, foot structures shown in FIGS. 90 to 92 are used. FIGS. 90 to 92 are plan views showing schematic constructions of known feet. In the figures, each of reference numerals 12 , 22 , and 32 denotes a side surface (outer side surface) which is remote from the other foot (foot which is attached to a leg which forms a pair with a leg on which the foot shown in each figure is attached). In addition, each of reference numerals 13 , 23 , and 33 denotes a side surface (inner side surface) which is adjacent to the other foot; each of reference numerals 14 , 24 , and 34 denotes a side surface at the front of the robot; and each of reference numerals 15 , 25 , and 35 denotes a side surface at the rear of the robot. In addition, each of reference numerals 11 , 21 , and 31 denotes an attachment for attaching the foot on an ankle of the corresponding leg of the robot. In the foot shown in FIG. 90 , the outer side surface 12 is curved outward. In addition, in the foot shown in FIG. 91 , the outer side surface 22 includes two planar surfaces such that the outer side surface 22 projects outward, and a vertex 26 is formed on a line where the two planar surfaces intersect. In addition, in the foot shown in FIG. 92 , projections 36 and 37 are formed on the outer side surface 32 and the inner side surface 33 , respectively, at the central positions thereof. The purpose of forming the outer side surfaces 12 , 22 , and 32 such that they project outward, as shown in the figures, is to improve the stability of the robot with respect to the outward (direction away from the other foot) rotation. In FIGS. 90 and 91 , in addition to the outer side surfaces 12 and 22 , the inner side surfaces 13 and 23 may also project outward in a manner similar to the outer side surfaces 12 and 22 , respectively. In the above-described known foot structures, since the outer side surface of each foot projects outward, it can be assumed that the stability with respect to the leftward and rightward rotational moment of the robot is increased in a state before falling motion starts. However, if the foot is constructed as shown in FIG. 90 , once the falling motion starts and the robot is somewhat tilted outward (to the left or right), the contact area between the outer edge (edge between the outer side surface and the bottom surface) and the road surface is gradually shifted. More specifically, the foot starts to roll along the curve of the outer edge. In addition, if the foot is constructed as shown in FIGS. 91 or 92 , the outer edge of the foot comes into point contact with the road surface at a single projecting point (the vertex 26 or a corner of the projection 36 ). Therefore, rotating motion around the yaw axis (axis which is perpendicular to the foot bottom surface) centered on the contact point occurs depending on the position of the gravity center of the robot in the falling motion. Generally, it is extremely difficult to predict how this rotating motion occurs. As described above, in the known foot structures, the attitude of the robot in the falling motion is not constant, and is difficult to predict. Therefore, once the falling motion starts, it is difficult to implement controls related to the falling motion, for example, control to avoid falling over, control to reduce the impact of falling over, control to recover from falling over, etc. Accordingly, the robot cannot help but fall over, and it is difficult to cause the robot to recover by itself. In addition, since the falling motion is not constant, in order to prevent the breakage of each part of the robot due to collision with the road surface when the robot falls over, it is necessary to increase the rigidity and the impact resistance of all of the parts which may collide with the road surface. Accordingly, there is a problem in that the cost of the robot increases. In addition, the legged mobile robots are currently moving from the research stage to practical application, and there are still many technical problems which must be solved. For example, although the state of the road surface (whether or not it is rough, the coefficient of friction thereof, etc.) has a large influence on the attitude stability control in legged walking motion and stable walking, this is not fully understood. In addition, in biped walking robots such as humanoids, the gravity center is at a higher position and the stability region of ZMP during walking is smaller compared to four-legged walking robots. Therefore, the problem of attitude variation depending on the state of the road surface is particularly important for the biped walking robots. When the walking motion on a road surface is considered, a walking method suitable for the state of the road surface is preferably used. Japanese Patent Application No. 2000-100708, which has been assigned to the present applicant, discloses a legged mobile robot which can perform suitable legged locomotion in accordance with the state of the road surface. In the legged mobile robot according to this publication, a surface contact sensor for determining the state of contact between a foot and a road surface and a relative-movement measurement sensor for measuring the relative movement (that is, slipping) between the road surface and the leg placed on the road surface are provided on the foot (plantar or sole) of each movable leg. Even when, for example, slipping occurs and the actual trajectory is shifted from a planned or scheduled trajectory, correction of a movement plan and motion control can be performed adaptively. In addition, when walking motion of human beings is considered, walking motion on a normal road surface and that on a slippery road surface, such as a snowy road surface, are generally different from each other. In addition, walking motion on a wooden floor and that on a thick carpet are also different from each other. Human beings walk in accordance with the state of the road surface while observing the situation with five senses, selecting how to walk from among experimentally-learned walking methods, and performing attitude control in accordance with on the situation. In addition, human beings select shoes or the like which are suitable for the road surface on which they walk, and thereby easily adapt themselves to extreme road conditions such as snowy roads and dirt roads. With respect to the walking stability of the robots, although the robots are required to walk on various kinds of road surfaces similarly to human beings, it is difficult for the robots to perform various walking motions similarly to human beings. On the other hand, with respect to the relationship between the robots and the road surface, when the size and the weight of the robots are similar to those of human beings, it can be assumed that the influence of the road surface on the walking state of the robots is similar to that on the walking state of human beings. In comparison, when the size and the weight of the robots are less than those of human beings, the influence of the state of the road surface may increase. As an example, a road surface which deforms when load is applied, such as a carpet, will be described below. When a human being walks on a carpet, even when the carpet is thick, the surface of the carpet is pressed at a region where a foot is placed and the road surface becomes stable since his or her weight is sufficiently large. In addition, the reaction force from fibers of the carpet has only a small influence on the walking motion. In comparison, when a small, light robot walks on the same carpet, a pressure applied to the surface of the carpet by a foot sole of the robot is small, and the surface of the carpet cannot be sufficiently pressed at a region where the foot is placed. As a result, a situation similar to that when a human being walks on a thick mattress occurs and the walking motion is largely influenced. It is difficult for the robots to perform various walking patterns like human beings, and the robots cannot easily adapt themselves to the road surface on which they are walking. In addition, the robots and human beings receive different kinds of influences from the road surface. Although the foot and the foot sole of the robots are widely researched and developed, it is currently difficult to obtain a perfect foot which can be adapted to any type of road surface from a both technical and financial point of view. In addition, the legged mobile robots are still in the research and development stage, and their development mainly aims to increase the adaptability of the robot's foot in work environments where the road surface is limited. Accordingly, as the legged mobile robots are transferred to practical application and product development to be used in people's living spaces, it is necessary to adapt them to various states of road surfaces. In view of the above-described situation, the present applicant has proposed a legged mobile robot having a foot which can be replaced according to the state of the road surface in Japanese Patent Application No. 2000-167681. In addition, the present applicant has also proposed a legged mobile robot having a foot which has a two-part structure including an instep which is connected to an ankle and a foot sole which is detachably attached to the instep such that it comes into contact with the road surface (Japanese Patent Application No. 2002-037997). In this structure, the foot sole can be replaced according to the state of the road surface. Since only the foot sole, which contributes most to the adaptation to the state of the road surface and which is worn most by coming into contact with the road surface, is replaced, many kinds of foot soles suitable for various states of road surfaces can be prepared at a low cost compared to the case in which the entire foot is replaced. In addition, when a foot or a foot sole of a legged mobile robot is replaced, settings for suitable foot motion, ZMP trajectory, trunk motion, upper limb motion, and height of hips change. Accordingly, it is necessary to change these settings. In order to suitably change these settings, information such as the shape of the foot or the foot sole, the coefficient of friction, and the weight of the foot or the foot sole must be provided to a main controller of the robot's main body. In this case, a method may be used in which the information related to the foot or the foot sole is stored in a ROM mounted in the robot's main body and a user inputs information for identifying the new foot or foot sole. However, in this method, information corresponding to all of the feet or the foot soles to be replaced must be stored in the ROM. Thus, if an extremely large number of feet or foot soles are prepared, the number of ROMs or the capacity of the ROM must be increased accordingly. This leads to a difficult problem if a sufficiently large space cannot be provided for accommodating the ROMs as in small legged mobile robots, and high costs are incurred if a large-capacity ROM is used. In addition, it is cumbersome for the user to input the above-described identification information each time the foot or the foot sole is replaced. In addition, in the above-described known foot structures, although the impact in the Z-axis direction applied to the foot sole by the road surface when the foot sole is place on the road surface can be somewhat absorbed with the elastic sheet or the leaf spring, a force applied in a specific or unspecific direction along a plane perpendicular to the Z-axis direction (X-Y plane) is not taken into account. More specifically, when the road surface has bumps and depressions, a part of the foot may interfere with the surface with bumps and depressions (be caught by the surface or stumble thereon) when an idling leg is placed on the road surface, and there is a risk that the upper body of the robot will lose balance and the attitude thereof will become unstable. This problem becomes more severe when a high-speed motion is performed since the reaction force from the road surface increases. In such a case, the robot takes an emergency avoidance motion based on a software process performed by control means of the robot. However, it is advantageous in view of stability control and walking control if this problem can be avoided or eased with a hardware structure of the foot. In addition, the foot is provided with various sensors for detecting basic information used by the main controller of the robot's main body to control the motion of each part, such as movable legs. For example, when the motion control of the robot is performed by using the ZMP as the criterion for stability evaluation, a plurality of force sensors for ZMP detection are disposed on the foot bottom surface (surface which comes into contact with the road surface) in order to measure the actual ZMP. In addition, the foot may also be provided with, for example, sensors for determining whether or not the foot is placed on the road surface, sensors for determining whether or not the foot placed on the road surface is slipping on the road surface, etc. The detection values obtained by the sensors are A/D converted and are input to a main controller of the robot's main body. Then, the main controller calculates the actual ZMP on the basis of the detection values and performs other calculation processes, and controls the motion of each part, such as the walking motion, on the basis of the calculation results. However, since the main controller of the robot's main body directly receives the outputs from the sensors mounted on the foot and performs necessary calculation processes including the ZMP calculation, there is a problem in that a large processing load is placed on the main controller. More specifically, a computing unit of the main controller which is mounted in the robot's main body performs complex and enormous calculations for, for example, setting the motion of the robot. Accordingly, if the computing unit of the main controller must calculate the actual ZMP on the basis of the outputs from the above-described ZMP detection sensors and process outputs from other sensors, a large calculation load is placed on the computing unit of the main controller. In addition, in order to supply the outputs from the sensors provided on each foot to the main controller of the robot's main body, complex wiring is necessary to connect the sensors and the main controller. Furthermore, when the foot is replaced, it may be necessary to change the wiring in the robot's main body if the kind, the characteristics, the number, etc., of the sensors provided on the foot are changed. In such a case, there is a problem in that a large workload is required for replacing the foot. |
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a front view of a “human-shaped” legged mobile robot 100 according to a first embodiment of the present invention which is in an upright position. FIG. 2 is a rear view of the legged mobile robot 100 in an upright position. FIG. 3 is a diagram showing a schematic construction of a control system of the legged mobile robot 100 . FIG. 4 is a perspective view of a foot of the legged mobile robot shown in FIG. 1 according to a first example. FIG. 5 is a side view of the foot of the legged mobile robot shown in FIG. 1 according to the first example. FIG. 6 is a bottom view of the foot of the legged mobile robot shown in FIG. 1 according to the first example. FIG. 7 is a sectional view of FIG. 6 cut along line A-A. FIG. 8 is a sectional view of FIG. 6 cut along line B-B. FIG. 9 is a perspective view of a foot of the legged mobile robot according to a second example. FIG. 10 is a sectional side view of the foot of the legged mobile robot according to the second example. FIG. 11 is a perspective view of a foot of the legged mobile robot according to a third example. FIG. 12 is a side view of the foot of the legged mobile robot according to the third example. FIG. 13 is a bottom view of the foot of the legged mobile robot according to the third example. FIG. 14 is a diagram for explaining dimensions of the foot of the legged mobile robot shown in FIG. 11 . FIG. 15 is a diagram for explaining the shape of a doorsill which is assumed to be stepped on by the foot of the legged mobile robot shown in FIG. 11 . FIG. 16 is a perspective view of a foot of the legged mobile robot according to a fourth example. FIG. 17 is a side view of the foot of the legged mobile robot according to the fourth example. FIG. 18 is a bottom view of the foot of the legged mobile robot according to the fourth example. FIG. 19 is a sectional view of FIG. 18 cut along line A-A. FIG. 20 is a sectional view of FIG. 18 cut along line B-B. FIG. 21 is a sectional view of FIG. 18 cut along line C-C. FIG. 22 is a diagram for explaining dimensions of the foot of the legged mobile robot shown in FIG. 16 . FIG. 23 is a diagram for explaining the shape of a doorsill which is assumed to be stepped on by the foot of the legged mobile robot shown in FIG. 16 . FIG. 24 is a perspective view of a foot of the legged mobile robot according to a fifth example. FIG. 25 is a side view of the foot of the legged mobile robot according to the fifth example. FIG. 26 is a bottom view of the foot of the legged mobile robot according to the fifth example. FIG. 27 is a sectional view of FIG. 26 cut along line A-A. FIG. 28 is a sectional view of FIG. 26 cut along line B-B. FIG. 29 is a sectional view of FIG. 26 cut along line C-C . FIG. 30 is a perspective view of a foot of the legged mobile robot according to a sixth example. FIG. 31 is a side view of the foot of the legged mobile robot according to the sixth example. FIG. 32 is a bottom view of the foot of the legged mobile robot according to the sixth example. FIG. 33 is a diagram for explaining dimensions of the foot of the legged mobile robot shown in FIG. 30 . FIG. 34 is a diagram for explaining the shape of a doorsill which is assumed to be stepped on by the foot of the legged mobile robot shown in FIG. 30 . FIG. 35 is a perspective view of a foot of the legged mobile robot according to a seventh example. FIG. 36 is a side view of the foot of the legged mobile robot according to the seventh example. FIG. 37 is a bottom view of the foot of the legged mobile robot according to the seventh example. FIG. 38 is a sectional view of FIG. 37 cut along line A-A. FIG. 39 is a sectional view of FIG. 37 cut along line B-B. FIG. 40 is a perspective view of a foot of the legged mobile robot according to an eighth example. FIG. 41 is a side view of the foot of the legged mobile robot according to the eighth example. FIG. 42 is a side view of a foot of the legged mobile robot according to a ninth example. FIG. 43 is a bottom view of the foot of the legged mobile robot according to the ninth example. FIG. 44 is a bottom view of a foot of the legged mobile robot according to a tenth example. FIG. 45 is a side view of the foot of the legged mobile robot according to the tenth example. FIG. 46 is a plan view showing a foot of the legged mobile robot according to an eleventh structure. FIG. 47 is a diagram for explaining a behavior of the foot of the legged mobile robot according to the eleventh structure when the robot falls over. FIG. 48 is a plan view showing a foot of the legged mobile robot according to a twelfth structure. FIG. 49 is a diagram for explaining a behavior of the foot of the legged mobile robot according to the twelfth structure when the robot falls over. FIG. 50 is a plan view showing a foot of the legged mobile robot according to a thirteenth structure. FIG. 51 is a plan view showing a foot of the legged mobile robot according to a fourteenth structure. FIG. 52 is a diagram showing the state in which the foot of the legged mobile robot deforms due to the weight. FIG. 53 is a diagram showing the state in which the foot of the legged mobile robot is placed on a step. FIG. 54 is a diagram showing the state in which the foot of the legged mobile robot walks on a carpet. FIG. 55 is a diagram for explaining the motion of the foot of the legged mobile robot when the corners of the bottom surface of the foot are rounded. FIG. 56 is a diagram showing the state in which a concavity stepped on by the foot of the legged mobile robot reaches the bottom surface (ceiling surface) of a plantar-arch portion through a flexible portion of the foot. FIG. 57 is a diagram showing the state in which the foot of the legged mobile robot steps on a relatively large step. FIG. 58 is a diagram showing the manner in which the flexible portion of the foot of the legged mobile robot deforms when the flexible portion is formed of a normal elastic material. FIG. 59 is a diagram showing the manner in which the flexible portion of the foot of the legged mobile robot deforms when the flexible portion is formed of a material with a relatively high flexibility. FIG. 60 is a diagram showing the state in which the foot of the legged mobile robot steps on an obstacle which can roll. FIG. 61 is a diagram showing the state in which the foot of the legged mobile robot steps on a relatively large obstacle which can roll. FIG. 62 is a diagram showing the state in which the foot of the legged mobile robot moves on a carpet. FIG. 63 is a side view showing a support structure of an instep (upper portion of a foot) and a foot bottom (sole of the foot) according to a first example. FIG. 64 is a sectional view of FIG. 63 cut along lint A-A. FIG. 65 is a perspective view showing a support structure of an instep (upper portion of a foot) and a foot bottom (sole of the foot) according to a second example. FIG. 66 is a sectional view of FIG. 65 cut along lint B-B. FIG. 67 is a plan view showing a support structure of an instep (upper portion of a foot) and a foot bottom (sole of the foot) according to a third example. FIG. 68 is a partially broken side view showing a support structure of an instep (upper portion of a foot) and a foot bottom (sole of the foot) according to a third example. FIG. 69 is a sectional view showing a connection/replacement structure of a leg and a foot at an ankle according to a first example. FIG. 70 is a sectional view showing the construction of the foot shown in FIG. 69 and a connecting part in the state in which the foot is connected to the ankle. FIG. 71 is a diagram showing a connection/replacement structure of a leg and a foot at an ankle according to a second example, where (A) is a top view, (B) is a side view, (C) is a back view, and (D) is a sectional side view when the foot is removed from the ankle. FIG. 72 is a diagram showing a state in which the structure of the foot according to the second example is changed, where (A) is a top view, (B) is a side view, (C) is a back view, and (D) is a sectional side view when the foot is connected to the ankle. FIG. 73 is a sectional view showing the construction of a foot and a connecting part according to a third example in the state in which the foot is connected to an ankle. FIG. 74 is a block diagram showing the structure of an instep circuit unit and a foot-sole circuit unit included in the foot. FIG. 75 is an exploded side view showing a part of a connection/replacement structure of a leg and a foot according to a fourth example. FIG. 76 is a plan view of the foot included in the connection/replacement structure of the leg and the foot according to the fourth example. FIG. 77 is an exploded side view showing a part of the foot included in the connection/replacement structure of the leg and the foot according to the fourth example. FIG. 78 is a bottom view of the foot included in the connection/replacement structure of the leg and the foot according to the fourth example. FIG. 79 is a diagram showing a connection/replacement structure of a leg and a foot according to a fifth example, and is a sectional view showing the construction of the foot and a connecting part in the state in which the foot is removed from an ankle. FIG. 80 is a diagram showing the connection/replacement structure of the leg and the foot according to the fifth example, and is a sectional view showing the construction of the foot and the connecting part in the state in which the foot is connected to the ankle. FIG. 81 is a bottom view of an instep included in the connection/replacement structure of the leg and the foot according to the fifth example. FIG. 82 is a diagram showing the state in which a known foot of a legged mobile robot deforms due to the weight. FIG. 83 is a diagram for,explaining a resistive-force-generation effective surface in the case in which the foot is in point contact with a road surface. FIG. 84 is a diagram for explaining the resistive-force-generation effective surface in the case in which the foot is in contact with the road surface such that the contact area is frame-shaped. FIG. 85 is a diagram showing the state in which the known foot of the legged mobile robot is placed on a step. FIG. 86 is a diagram showing the state in which the known foot of the legged mobile robot walks on a carpet. FIG. 87 is a diagram for explaining the motion of the known foot of the legged mobile robot when a corner of the bottom surface of the foot is caught by the road surface. FIG. 88 is a diagram showing the state in which the known foot of the legged mobile robot is placed a step. FIG. 89 is a diagram showing the state in which a known foot of the legged mobile robot having a plantar arch is placed on a step. FIG. 90 is a plan view showing an example of the construction of a foot. FIG. 91 is a plan view showing another example of the construction of a foot. FIG. 92 is a plan view showing another example of the construction of a foot. detailed-description description="Detailed Description" end="lead"? |
Aquatic plant harvester |
An aquatic harvester for use with an aquatic craft, the aquatic craft including sides, a bow and a stern, the aquatic harvester including a frame which includes one or more arms, the or each arm having a forward end portion and the or each arm being pivotally connected to the aquatic craft at a position spaced from the forward end, said forward end of the or each arm being adapted for connection with an implement, the apparatus further including means for controlling the pivotal position of the or each arm relative to the aquatic craft. |
1-13. (Cancelled) 14. An aquatic harvester for use with an aquatic craft, the aquatic craft including sides, a bow and a stern, the aquatic harvester including a frame which includes one or more arms, the or each arm having a forward end portion and the or each arm being pivotally connected to the aquatic craft at a position spaced from the forward end, said forward end of the or each arm being adapted for connection with an implement, the implement including a collection zone for collecting harvested material or articles, the harvester further including a suction pump on the vessel, and a transfer conduit between the suction pump and the implement arranged to transfer collected material or articles from the collection zone of the implement to the vessel, and means for controlling the pivotal position of the or each arm relative to the aquatic craft. 15. An aquatic harvester according to claim 14 including a pair of said arms, each arm having rearward ends remote from said forward ends, said rearward ends of said arms being pivotally connected with either side of said craft at a point generally amidships of said bow and said stern and said forward ends of said arms extending beyond the bow of said vessel, when said arms are pivoted to an approximately horizontal condition, and at least one transverse connection between said arms forward of said bow of said vessel with said arms in said horizontal condition. 16. An aquatic harvester according to claim 14 wherein a single arm is provided, the arm being disposed generally centrally of the underside of the vessel and extending in a direction between the stern and the bow. 17. An aquatic harvester according to claim 14 wherein said implement includes a collecting hood having said collection zone therein and a mouth opening for receiving harvested material or articles and an outlet opening, the conduit connecting between an inlet to said suction pump and said outlet opening of said collecting hood. 18. An aquatic harvester according to claim 17 further including a strainer assembly on the craft for receiving a flow of water with the harvested material or articles therein from the suction pump and releasing the water and retaining material or articles and a conduit extending from an outlet of said pump to said strainer assembly. 19. An aquatic harvester according to claim 18 wherein the strainer assembly includes a straining bag having at least a collapsed form and an open form, and means to support said straining bag in said open form below an outlet to said conduit from said pump outlet. 20. An aquatic harvester according to claim 19 wherein the means to support said straining bag includes a sloping platform at an elevation above at least a part of one side of the craft, said platform sloping towards the side of the craft and extending over the side of the craft, the platform being enclosed around its perimeter, other than to water flow over the side of the craft, and said bag is supported on said platform. 21. An aquatic harvester according to claim 20 wherein the bag includes closure means for closing the opening of said bag, and said means to support the straining bag allows release of the closed bag off said vessel. 22. An aquatic harvester according to claim 18 wherein the collecting hood includes a chopper at or adjacent said outlet opening for chopping plant debris received into said collecting hood into smaller portions, and a cutting head, extending across a bottom edge of said hood over the full width of said hood. 23. An aquatic harvester according to claim 22 further including at least one float attached to said forward end of said frame, said float supporting said forward end of said frame at or adjacent the water surface for allowing surface skimming by said collecting hood. 24. An implement for use in a harvester, the implement including a collecting hood, with a mouth opening for receiving harvested material and an outlet opening, the collecting hood being operatively connectible to a suction pump through a conduit connecting between an inlet to said suction pump and said outlet opening of said collecting hood. 25. An implement according to claim 24 wherein the collecting hood includes a chopper at or adjacent said outlet opening for chopping harvested material received into said collecting hood into smaller portions, and a cutting head, extending across a bottom edge of said hood over the full width of said hood. 26. An implement according to claim 24 wherein said collecting hood is separated into two zones each zone having a respective outlet opening associated therewith, each outlet opening being operatively connectible to the suction pump through respective conduits. |
<SOH> BACKGROUND TO THE INVENTION <EOH>1. Field of the Invention The present invention relates to aquatic plant harvesters, and in particular but not solely to weed harvesters for use in preparation and maintenance of lake and waterway shallow marine sporting facilities. The invention may also be useful in commercial aquatic plant harvesting, marine and fresh water. 2. Summary of the Prior Art Preparation and maintenance of lake and waterway sports facility includes the requirement to harvest and remove submerged and floating aquatic plants. The governing rules of certain sporting bodies require complete clearance to specified minimum depths. For example the International Rowing Body FISA requires a clear water zone to a depth of 3 metres below the hull of the racing craft. Plants requiring control in Australian facilities include but are not limited to: Potamogeton ochreatus, P. tricarinatus, P. perfoliatus, P. crispus, Myriophyllum verrucosum, Hydrilla verticillata, Vallisneria americana, Egeria densa, Water Milfoil, Canadian Pondweed, Salvinia and Typha. There are several existing barge or punt mounted marine harvesters intended for use in this area. These include the Aqua-Equip harvester manufactured by the Attosar Corporation of Oatville Ontario Canada. This machine includes a barge with an angled conveyor extending into the water from its leading edge. The angled conveyor is formed of an open chain grid. A cutting head is provided at the lower submerged end of the angled conveyor to cut marine weed. The weed is intended to float onto the conveyor and be conveyed up to a catchment trough. Entrained water spills through the open grid of the conveyor as it is carried from the water. Similar arrangements are also used in the other vessels that the applicants are aware of. Experience has shown that these arrangements provide inefficient collection of the cut weed leaving large quantities of floating vegetative material. Also, with many exotic weeds the weeds will propagate from severed nodes. The severed nodes are relatively small and prone to falling through the open conveyor grids. These disadvantages have generally required the use of additional surface clean up vessels. These clean up vessels may operate during and after harvesting, pulling or pushing a scoop net through the surface region to remove remaining vegetable material. Another difficulty is that these harvesters create a significant bow pressure wave when moving forward at reasonable speeds. The inventors believe this is due to the large frontal area defined by the conveyor. Pressure waves can cause redistribution of plant material leading to large amounts left uncut. This reduces the effective operating speed of the harvester. |
<SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide an aquatic plant harvester and/or an aquatic surface strainer and/or an aquatic environment bank mower which at least goes some way towards overcoming the above disadvantages or which will at least provide the industry with a useful choice. According to one aspect of the present invention there is provided an aquatic harvester for use with an aquatic craft, the aquatic craft including sides, a bow and a stern, the aquatic harvester including a frame which includes one or more arms, the or each arm having a forward end portion and the or each arm being pivotally connected to the aquatic craft at a position spaced from the forward end, said forward end of the or each arm being adapted for connection with an implement, the apparatus further including means for controlling the pivotal position of the or each arm relative to the aquatic craft. According to another aspect of the present invention there is provided an implement for use in a harvester, the implement including a collecting hood, with a mouth opening for receiving harvested material and an outlet opening, the collecting hood being operatively connectible to a suction pump through a conduit connecting between an inlet to said suction pump and said outlet opening of said collecting hood. According to another aspect of the present invention there is provided an aquatic plant harvester including: a vessel having a bow and a stern, and a frame having a pair of arms, each arm having forward and rearward ends, said rearward ends of said arms being pivotally connected with either side of said vessel at a point amidships of said bow and said stern and said forward ends of said arms extending beyond the bow of said vessel, with said arms pivoted to an approximately horizontal condition, and at least one transverse connection between said arms, forward of said bow of said vessel with said arms in said horizontal condition, said forward ends of said arms being adapted for connection with an implement, and means for controlling the pivotal position of said arms relative to said vessel. The harvester may further include a suction pump and drive therefor mounted on said vessel, an implement connected with said forward end of said frame, said implement include a collecting hood, with a mouth opening for receiving aquatic debris and an outlet opening, and a conduit connecting between the inlet of said suction pump and said outlet opening of said collecting hood. The harvester may further include a strainer assembly on said vessel for receiving a flow of water with entrained plant debris, releasing said water and retaining said plant debris, and a conduit extending from the outlet of said pump to said strainer. In one preferred form the strainer assembly includes a straining bag having at least a collapsed form and an open form, and means to support said straining bag in said open form below The means to support said straining bag may include a sloping platform at an elevation above at least a part of the side of said boat, said platform sloping towards said side of said vessel and extending over said side of said vessel, said platform being enclosed around its perimeter, other than to water flow over said side of said vessel, and said bag is supported on said platform. Preferably, the bag includes closure means for closing the opening of said bag, and said means to support the straining bag allows release of the closed bag off said vessel. In one form the collecting hood includes a chopper at or adjacent said outlet port for chopping plant debris received into said collecting hood into smaller portions. The implement may further include a cutting head, extending across a bottom edge of said hood over the full width of said hood. At least one float attached to said forward end of said frame, said float supporting said forward end of said frame at or adjacent the water surface for allowing surface skimming by said collecting hood. In another form of the invention the harvester may include an implement connected with said forward end of said frame, said implement including a cutting head extending between said arms of said frame. An electronic navigation system may be provided which includes a positioning system for monitoring the position of said vessel, means to accumulate said position of said vessel as a plottable path representable on a display at a certain scale, the width of said path at said certain scale approximating the width of said vessel, and a display for displaying said path. According to another aspect of the present invention there is provided an aquatic harvester including: a vessel having a bow and a stern a suction pump and drive therefor, mounted on said vessel, an implement including a collecting hood with a mouth opening for receiving aquatic borne plant debris and an outlet opening, a conduit connecting between the inlet of said suction pump and said outlet of said collecting hood, and a connection arrangement between said implement and said vessel which supports said implement outboard of said vessel at a selected depth. There may be further provided a strainer assembly which may be of the type described earlier. In addition, the harvester may include a collecting hood of the type described earlier. In one form the cutting head may include a first bar including a set of parallel and forwardly extending guide prongs, and a second bar reciprocable relative to said first bar and carrying a set of forwardly extending spaced apart knives, said spacing of said knives corresponding with said spacing of said guide prongs, reciprocation of said second bar reciprocating said knives to cut material between said knives and said guide prongs, said guide prongs extending at least 50 millimetres forward of said first bar. A float may be provided of the type described herein. According to yet another aspect of the present invention there is provided an aquatic plant harvester including: a vessel having a bow in the stern, an implement including a cutting head extending between said arms of said frame, and a connection arrangement between said implement and said vessel which supports said implement outboard of said vessel at a selected depth. According to yet another aspect of the present invention there is provided an aquatic plant harvester including: a vessel having a bow in the stern, an electronic navigation system including a positioning system for monitoring the position of said vessel, means to accumulate said position of said vessel as a plottable path representable on a display at a certain scale, the width of said path at said certain scale approximating the width of said vessel, and a display for displaying said path, a working implement for collecting aquatic plant material, and a connection arrangement between said implement and said vessel which 10 supports said implement outboard of said vessel at a selected depth. Preferably, the navigation system includes a processing unit and a memory unit, said processing unit executing programs stored in said memory unit, and said stored programs include means for allowing storage of geographical information concerning a local aquatic environment in said memory unit, said information including vegetation specific information such as the location of plant assemblages. There may further be provided means for providing an output indicative of the working depth of said implement, said output provided as an input to said navigation system, and said programs include program means for updating said vegetation specific information based on the work progression of said vessel and the working depth of said implement. According to yet another aspect of the present invention there is provided an aquatic harvester including a vessel, the harvester including one or more arms the or each arm having a working end portion to which an implement is adapted to be operatively connected, the or each arm being operatively connected to the vessel at a pivot mounting spaced from the working end portion so that the working head can be moved to selected depth. In one form the vessel has a bow and a stern, the pivot mounting being disposed in the region of the stern of the vessel. Preferably, the pivot mounting is disposed at an end portion of the or each arm remote from the working end portion. Preferably, the or each arm is movable between a position in which is generally horizontal to an inclined or vertical position. Preferably, the implement when attached to the or each arm extends forwardly of the bow of the vessel. According to one form of the invention a single arm is provided. Preferably, the arm is disposed generally centrally of the underside of the vessel and extends in a direction between the stern and the bow. Preferably, the harvester further includes a suction pump mounted on the vessel and one or more conduits extending between the suction pump and the work end portion of the arm, the or each conduit extending along the arm. The harvester may further include a strainer assembly on vessel for receiving a flow of water with entrained plant debris, releasing the water and retaining the plant debris, and a conduit extending from the outlet of the pump to the strainer. The strainer assembly may be in the form described earlier. The implement may also be of any of the types described earlier. The harvester further includes transfer apparatus for transferring filled bags (which may define the strainer) from the vessel, the transfer apparatus including a rail disposed above the strainer assembly and extending therefrom, and a carriage operatively mounted to the rail for movement therealong and means for connecting the strainer to the carriage. The rail may include a section where the strainer or bag is connected to the carriage and a holding section which receives the carriage for subsequent disposal. According to yet another aspect of the present invention there is provided a work head for use with an aquatic harvester, the work head including a collecting hood with a mouth opening and an outlet opening said hood being separated into two zones, each having an outlet opening operatively communicating with a respective conduit. To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. Preferred embodiments of the invention will be hereinbefore described with reference to the accompanying drawings, and in those drawings: FIG. 1 is a perspective view of a harvester according to the preferred embodiment of the present invention. The harvesting head is shown in a cutting configuration and in each of a stowed and harvesting condition. FIG. 2 is a perspective view of a harvester according to the preferred embodiment of the present invention, with the harvesting head shown in a surface skimming configuration and condition. FIG. 3 is a perspective view of the cutting head in use in FIG. 1 , with partial cutaway to show the secondary plant chopper. FIG. 4 is a perspective view of the skimming head in use in FIG. 2 . FIG. 5 is a side elevation of the harvesting unit arranged for transport on a transport trailer. FIG. 6 is a perspective view of a harvester with suction hood removed for bank clearance work. FIG. 7 is a block diagram of a GPS navigation system according to another aspect of the invention. FIG. 8 is a schematic perspective view of a harvester according to another preferred embodiment of the present invention; FIG. 9 is a more detail view of part of the harvester shown in FIG. 8 ; FIG. 10 is a schematic view of a further embodiment of a work head for use with a harvester according to the invention; FIG. 11 is a schematic view of a further embodiment of work head according to the invention; FIG. 12 is a side elevation of the harvester shown in FIG. 1 ; and FIGS. 13 and 14 are schematic illustrations of a system for transferring collection bags from the harvester. detailed-description description="Detailed Description" end="lead"? |
Door for washing machne and method for manufacturing the same |
Door 30 for a washing machine including a body 31 designed to open/close an opening 12a for introducing laundry into a tub 11a, a transparent part 31a formed at least a part of the body 31 for having a view of an inside of the tub 11a, and a first layer 33 of a hydrophilic material on an inside surface of the transparent part 31a. |
1. A door for a washing machine comprising: a body designed to open/close an opening for introducing laundry into a tub; a transparent part formed at least a part of the body for having a view of an inside of the tub; and a first layer of a hydrophilic material on an inside surface of the transparent part. 2. The door as claimed in claim 1, wherein the body is transparent, entirely. 3. The door as claimed in claim 1, wherein the body and the transparent part are formed of ABS resin or PC resin. 4. The door as claimed in claim 1, wherein the first layer is a coated layer formed by coating a liquid hydrophilic material. 5. The door as claimed in claim 1, wherein the first layer is a film layer formed by attaching a film of a hydrophilic material. 6. The door as claimed in claim 1, wherein the first layer is formed of cross-linked polyurethane. 7. The door as claimed in claim 1, further comprising a second layer of a high hardness material on an outside of the transparent part. 8. The door as claimed in claim 7, wherein the second layer is a coated layer formed by coating a liquid high hardness material. 9. The door as claimed in claim 7, wherein the second layer is a film layer formed by attaching a film of a high hardness material. 10. The door as claimed in claim 7, wherein the second layer is formed of cross-linked polyurethane. 11. A method for fabricating a door for a washing machine, comprising the steps of: forming a body of a door to include a transparent part, at least partly; washing the transparent part; and forming a first layer of a hydrophilic material on an inside surface of the transparent part. 12. The method as claimed in claim 11, wherein the body and the transparent part are formed by injection molding of a plastic. 13. The method as claimed in claim 12, wherein the body and the transparent part are formed of ABS resin or PC resin. 14. The method as claimed in claim 11, wherein the step of washing includes the step of washing the transparent part with a wash liquid. 15. The method as claimed in claim 14, further comprising the step of drying the transparent part for a predetermined time period after the step of washing. 16. The method as claimed in claim 11, wherein the step of washing includes the step of blowing compressed air to the transparent part. 17. The method as claimed in claim 11, wherein the step of forming a first layer includes the step of coating a liquid hydrophilic material on the transparent part. 18. The method as claimed in claim 17, wherein the step of coating includes; the step of spraying the hydrophilic material onto the transparent part, or the step of dipping the transparent part into the hydrophilic material. 19. The method as claimed in claim 17, further comprising the step of drying the transparent part after the step of coating. 20. The method as claimed in claim 19, wherein the transparent part is dried in a room at a room temperature for at least 24 hours. 21. The method as claimed in claim 11, wherein the step of forming a first layer includes the step of attaching a film of hydrophilic material to the transparent part. 22. The method as claimed in claim 11, wherein the first layer is formed of cross-linked polyurethane. 23. The method as claimed in claim 11, further comprising the step of forming a second layer of a high hardness material on an outside of the transparent part after the step of washing. 24. The method as claimed in claim 23, wherein the step of forming a second layer includes the step of coating a liquid high hardness material on the transparent part. 25. The method as claimed in claim 24, further comprising the step of drying the transparent part after the step of coating. 26. The method as claimed in claim 23, wherein the step of forming a second layer includes the step of attaching a film of a high hardness material to the transparent part. 27. The method as claimed in claim 23, wherein the second layer is formed of cross-linked polyurethane. 28. A washing machine comprising; a housing; a tub mounted in the housing rotatable by predetermined power means for washing laundry; and a door including a body for opening/closing an opening in the housing so as to be in communication with the tub, a transparent part formed at least a part of the body for having a view of an inside of the tub, and a first layer of a hydrophilic material on an inside surface of the transparent part. 29. The method as claimed in claim 28, wherein the first layer is a coated layer formed by coating a liquid hydrophilic material. 30. The method as claimed in claim 28, wherein the first layer is a film layer formed by attaching a film of a hydrophilic material. 31. The method as claimed in claim 28, further comprising a second layer of a high hardness material on an outside of the transparent part. 32. The door as claimed in claim 31, wherein the second layer is a coated layer formed by coating a liquid high hardness material. 33. The door as claimed in claim 31, wherein the second layer is a film layer formed by attaching a film of a high hardness material. 34. The door as claimed in claim 28, wherein the first or second layer is formed of cross-linked polyurethane. 35. A door for a washing machine fabricated by the steps of: forming a body of a door to include a transparent part, at least partly; washing the transparent part; and forming a first layer of a hydrophilic material on an inside surface of the transparent part, and forming a second layer of a high hardness material on an outside surface of the transparent part. 36. The door as claimed in claim 35, wherein the step of forming a first layer and a second layer includes the step of coating a liquid hydrophilic material and a high hardness material to an inside and an outside of the transparent part respectively, or the step of attaching a film of a hydrophilic material and a film of a high hardness material to the inside and the outside of the transparent part respectively. 37. The door as claimed in claim 36, wherein the hydrophilic material and the high hardness material are cross-linked polyurethane. |
<SOH> BACKGROUND ART <EOH>In general, the washing machine is provided with a tub provided therein for rotating and washing laundry introduced therein. For introduction of the laundry, or taking out the laundry, a housing of the washing machine is provided with a door. It is required for a user to open the door, in general formed of a non-transparent material, for confirmation of a state of the laundry during washing. However, in general, the washing machine is designed to stop operation of the washing machine if the door is opened, for the safety of the user. Therefore, unnecessary opening of the door may cause a prolonged total washing time period. Under this reason, a partly transparent door has been developed, for having a view of an inside of the tub even during the washing. However, even with the partly transparent door, the user can not have the view of the inside of the tub due to the door clouded up with steam in a case hot washing water is used inside of the tub. Moreover, the door, formed in general of a plastic, becomes to have scratches during use, which makes the user difficult to determine an inside state of the tub as the scratches increases. |
<SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention: In the drawings: FIG. 1 illustrates a perspective view showing a washing machine having a door of the present invention provided thereto; FIG. 2 illustrates a partial perspective view showing a washing machine door of the present invention; FIGS. 3A and 3B illustrate partial sections each showing a door of the present invention; and FIG. 4 illustrates a flow chart showing the steps of a method for fabricating a washing machine door in accordance with a preferred embodiment of the present invention. detailed-description description="Detailed Description" end="lead"? |
Enhanced shutter control for images that are faded into a stereo microscope |
The invention relates to a stereo microscope, which as a microscope used for operations comprises a viewing output for a surgeon (41) and at least one additional viewing output for an assistant (40). The stereo microscope is characterized by shutters (17a to 20b) for selectively screening off object information. |
1. A stereo microscope comprising at least one switchable shutter for switching off the object information located in front of the beam splitter for fading-in the additional information, and at least one second switchable shutter located in front of the surgeons ocular. 2. A stereo microscope comprising at least one switchable shutter for switching off the object information located in front of a beam splitter for fading-in and at least one second switchable shutter located in front of the surgeons and the assistants oculars. 3. A stereomicroscope as in claim 1 with a control device which is configured to open and close at least one of the switchable shutters on the basis of operator-specific or application-specific instructions. 4. A stereomicroscope as in claim 3 with a control device which detects the actual position of the faded-in additional information and to accordingly sets the shutter control. 5. A stereomicroscope as in claim 3 with a control device which detects the current rotational position of the assistant prism (aside or behind) and to accordingly sets the shutter control for the assistant located in the rear. 6. A stereomicroscope with a switchable fading-in of additional information into the left-hand beam path, the right-hand beam path or both. |
Electrolytic reduction of metal oxides |
An electrolytic cell and a method of electrolytically reducing a metal oxide, such as titania, in a solid state are disclosed. The electrolytic cell includes (a) a molten electrolyte, (b) a cathode in contact with the electrolyte, the cathode being formed at least in part from the metal oxide, and (c) a molten metal anode (such as silver or copper) in contact with the electrolyte. |
1. An electrolytic cell for electrolytic reduction of a metal oxide in a solid state, which electrolytic cell includes (a) a molten electrolyte, (b) a cathode in contact with the electrolyte, the cathode being formed at least in part from the metal oxide, and (c) a molten metal anode in contact with the electrolyte. 2. The electrolytic cell defined in claim 1 wherein the metal of the molten metal anode has a relatively high saturation level for oxygen at the operating temperature of the cell. 3. The electrolytic cell defined in claim 1 wherein the metal of the molten metal anode is chosen such that its melting point is within the operating temperature ranges of the electrolyte. 4. The electrolytic cell defined in claim 1 wherein the melting point of the metal of the molten metal anode is higher than the melting point of the electrolyte and lower than the vaporisation and/or decomposition temperature of the electrolyte. 5. The electrolytic cell defined in claim 1 wherein the metal of the molten metal anode has a very low solubility in the molten electrolyte at the cell operating temperatures, 6. The electrolytic cell defined in claim 1 wherein the metal of the molten metal anode is silver or copper. 7. The electrolytic cell defined in claim 1 further including a means for removing oxygen that has diffused into the molten metal anode from the cell. 8. The electrolytic cell defined in claim 7 wherein the cell oxygen removal means includes a duct that communicates with the molten metal anode and a device to create a partial pressure reduction between the molten metal anode and a head of molten metal within the duct. 9. A method of electrolytically reducing a metal oxide in a solid state in an electrolytic cell, which electrolytic cell includes (a) a molten electrolyte, (b) a cathode in contact with the electrolyte, the cathode being formed at least in part from the metal oxide, and (c) a molten metal anode in contact with the electrolyte, which method includes applying a cell potential across the anode and the cathode. 10. The method defined in claim 9 including maintaining the cell temperature above the melting points of the electrolyte and the metal of the metal anode. 11. The method defined in claim 9 including applying a cell potential above a decomposition potential of at least one constituent of the electrolyte so that there are cations of a metal other than that of the cathode metal oxide in the electrolyte. 12. The method defined in claim 9 wherein the metal oxide is a titanium oxide. 13. The method defined in claim 9 wherein the metal oxide is titania. 14. The method defined in claim 9 wherein the electrolyte is a CaCl2-based electrolyte that includes CaO as one of the constituents. 15. The method defined in claim 14 including maintaining the cell potential above the decomposition potential for CaO. 16. The method defined in claim 14 including maintaining the cell potential below the decomposition potential for CaCl2. 17. The method defined in claim 14 including maintaining the cell potential below 3.0V. 18. The method defined in claim 14 including maintaining the cell potential below 2.5V. 19. The method defined in claim 14 including maintaining the cell potential below 2.0V. 20. The method defined in including maintaining the cell potential at least 1.5V. |
<SOH> 2. BACKGROUND OF AND PRIOR ART TO THE INVENTION <EOH>The present invention was made during the course of an on-going research project on the electrolytic reduction of titania (TiO 2 ) carried out by the applicant. During the course of the research project the applicant carried out experimental work on an electrolytic cell that included a graphite crucible that formed an anode of the cell, a pool of molten CaCl 2 -based electrolyte in the crucible, and a cathode that included solid titania. The CaCl 2 -based electrolyte was a commercially available source of CaCl 2 , namely calcium chloride dihydrate, that decomposed on heating and produced a very small amount of CaO. The applicant operated the electrolytic cell at a potential above the decomposition potential of CaO and below the decomposition potential of CaCl 2 . The applicant found that the cell could electrolytically reduce titania to titanium with very low concentrations of oxygen. The applicant does not have a clear understanding of the electrolytic cell mechanism at this stage. Nevertheless, whilst not wishing to be bound by the comments in this paragraph, the applicant offers the following comments by way of an outline of a possible cell mechanism. The applicant believes that operating the experimental electrolytic cell above a potential at which the CaCl 2 -based electrolyte partially decomposed had the result of producing Ca ++ cations that migrated to the vicinity of the titania in the cathode and provided a driving force that facilitated extraction of O −− anions produced by electrolytic reduction of titania to titanium in the cathode. The applicant also believes that the O −− anions, once extracted from the titania, migrated to the anode and reacted with anode carbon and produced CO and released electrons that facilitated electrolytic reduction of titania to titanium in the cathode. In addition, the applicant believes that carbon in the anode reacted with Ca ++ cations and produced a complex calcium carbide. The experimental worked carried out by the applicant produced evidence of Ca metal in the electrolyte. The applicant believes that the Ca metal was the result of electrodeposition of Ca ++ cations as Ca metal on electrically conductive sections of the cathode and that at least part of the Ca metal dissolved in the electrolyte and migrated to the vicinity of the titania in the cathode and participated in chemical reduction of oxides. However, notwithstanding that the cell could electrolytically reduce titania to titanium with very low concentrations of oxygen, the applicant also found that there were relatively significant amounts of carbon transferred from the anode to the electrolyte and to the titanium produced at the cathode under a wide range of cell operating conditions. Carbon in the titanium is an undesirable contaminant. In addition, carbon transfer was responsible for low energy efficiency of the cell. Both problems are significant barriers to commercialisation of electrolytic reduction technology. The applicant carried out experimental work to identify the mechanism for carbon transfer and to determine how to minimise carbon transfer and/or to minimise the adverse effects of carbon transfer. |
<SOH> 3. SUMMARY OF INVENTION <EOH>Broadly, the invention resides in replacing the carbon anode with a molten metal anode. According to the present invention there is provided an electrolytic cell for electrolytic reduction of a metal oxide in a solid state, which electrolytic cell includes (a) a molten electrolyte, (b) a cathode formed at least in part from the metal oxide in contact with the electrolyte, and (c) a molten metal anode in contact with the electrolye. Preferably the metal of the molten metal anode has a relatively high saturation level for oxygen at the operating temperature of the cell. Preferably the metal is chosen such that its melting point is within the operating temperature ranges of the electrolyte. Preferably the melting point of the metal of the molten metal anode is higher than the melting point of the electrolyte and lower than the vaporisation and/or decomposition temperature of the electrolyte in order to prevent electrolyte consumption and removal through vaporisation. Preferably the metal of the molten metal anode has a very low solubility in the molten electrolyte at the cell operating temperatures, as high solubility is detrimental because the anode metal will deplete and deposit on the cathode. The latter might not be a serious problem where there is low solubility and reactability of the metal with the cathode metal at the operating temperature. Preferably the metal of the molten metal anode is silver or copper. The solubility of oxygen in the Ag—O system at 1000° C. is around 0.32% by weight. Ag has a melting point of 960° C., which is about 300 to 100° C. above the melting point of alkali and alkaline earth halides that provide suitable electrolytes. The solubility of oxygen in the Cu—O system at 1100° C. is 0.39% by weight. The melting point of copper is 1083° C., which is well below the boiling points of the above mentioned electrolytes. Preferably the electrolytic cell further includes a means for removing oxygen that has diffused into the molten metal anode from the cell. Such an “oxygen scavenging pump” means can have a number of different forms. One option includes a duct that communicates with the molten metal anode and a device to create a partial pressure reduction between the molten metal anode and a head of molten metal within the duct. An advantage of an “oxygen scavenging pump” means is that the amount of the molten metal anode required can be minimised, since the saturation wt % limits of oxygen within the molten anode metal are no longer the sole determining parameter of oxygen uptake by the anode. For example, in order to reduce log of titania to pure titanium, 1 kg Ag would be required in the absence of an oxygen scavenging pump means to remove substantially all of the oxygen from the molten metal anode. Continuous removal of oxygen from the molten metal anode facilitated by the means allows the process to be performed continuously, as compared with batch processing. According to the present invention there is also provided a method of electrolytically reducing a metal oxide in a solid state in an electrolytic cell, which electrolytic cell includes (a) a molten electrolyte, (b) a cathode in contact with the electrolyte, the cathode being formed at least in part from the metal oxide, and (c) a molten metal anode in contact with the electrolye, which method includes applying a cell potential across the anode and the cathode. Preferably the method includes maintaining the cell temperature above the melting points of the electrolyte and the metal of the metal anode. Preferably the method includes maintaining the cell temperature below the vaporisation and/or decomposition temperatures of the electrolyte. Preferably the method includes applying a cell potential above a decomposition potential of at least one constituent of the electrolyte so that there are cations of a metal other than that of the cathode metal oxide in the electrolyte. Preferably the metal oxide is a titanium oxide. It is preferred that the metal oxide be titania. In a situation in which the metal oxide is titania it is preferred that the electrolyte be a CaCl 2 -based electrolyte that includes CaO as one of the constituents. In such a situation it is preferred that the method includes maintaining the cell potential above the decomposition potential for CaO. It is also preferred that the method includes maintaining the cell potential below the decomposition potential for CaCl 2 . It is preferred that the method includes maintaining the cell potential less than 3.0V. It is preferred particularly that the method includes maintaining the cell potential below 2.5V. It is preferred more particularly that the method includes maintaining the cell potential below 2.0V. It is preferred that the method includes maintaining the cell potential at least 1.5V. The following example illustrates an application of the invention in the process of reducing titania into substantially pure titanium using an electrolytic cell constructed in accordance with the present invention and as illustrated schematically in FIG. 1 . |
Spraying device for spraying liquids, in particular, for spraying liquids for agricultural purposes |
A Spraying assembly for spraying liquids for agricultural purposes is provided whose respective sprayer valves attached to a common liquid supply line are at least configured in the form of valve housings whose pair of valve channels share a common distributor bore. This distributor bore allows connecting the bodies of valve housings in one of two positions in order that, provided that they are connected using a t-shaped fitting, they may be arranged either with their valve bores lined up in rows extending to the front or rear of the liquid supply line, as well as ahead of or behind the liquid supply line and aligned parallel thereto. Since one embodiment also provides a rotatable pipe-T joint, the dual-sprayer-nozzle valve units may also be arranged beneath the liquid supply line, which yields a large number of opportunities for laying out the sprayer nozzles, in spite of the simple means available for connecting them. |
1-10. (Cancelled). 11. Spraying assembly for spraying liquids, comprising: a spray bar arrangement mountable at an agricultural vehicle; a liquid supply line, having spaced branches; spray nozzle assemblies which each include at least two spray nozzles which are independently controlled by a spray valve controlled pneumatically or electrically, and a distribution duct connecting the spray valves and having at least two connecting openings which include a coupler sleeve; and fittings connected to the branches of the liquid supply line, each fitting including a T-shaped distributor channel with at least two outlets, each outlet having an interface capable of attaching a spray nozzle assembly; wherein the spray nozzle assemblies are mounted to the fittings and the liquid supply line is mounted to the spray bar arrangement. 12. Spraying assembly according to claim 11, wherein each fitting is detachable from the branch of the liquid supply line and includes a clamping fixture. 13. Spraying assembly according to claim 11, wherein a first coupler sleeve is centered between the spray valves and a second coupler sleeve is arranged perpendicularly to the first coupler sleeve. 14. Spraying assembly according to claim 12, wherein the fitting comprises a nipple to ensure a proper attachment to the branch of the liquid supply line. 15. Spraying assembly according to claim 14, wherein the fitting is rotatably attached to the nipple. 16. Spraying assembly according to claim 15, wherein the fitting is attachable to the nipple in at least two positions separated by 90°. 17. Spraying assembly according to claim 16, wherein the fitting and the nipple are connected by a snap-lock. 18. Spraying assembly according to claim 11, the spray valve including a pneumatically actuatable roller membrane or a pneumatically actuatable piston, and a spring, wherein a preload on the spray valve is applied by the spring. 19. Spraying assembly according to claim 18, wherein the spray valve includes a face surface with a circumferential sealing rim engageable with an O-ring seal included in a valve housing. 20. Spraying assembly according to claim 18, wherein the valve housing includes a bayonet-lock fitting for attaching the spray-nozzle. 21. Spray nozzle assembly for spraying liquids, comprising: a valve housing having at least two valve bores, wherein each valve bore includes a valve outlet; a distribution duct including a first opening and a second opening and connecting the valve bores; respective valve bodies located in the respective valve bores, wherein each valve body is controllably movable independently by pneumatic or electric forces; and spray nozzles connected to the respective valve outlets. 22. Spray nozzle assembly according to claim 21, wherein the first and the openings of the distribution duct are arranged perpendicularly to each other. 23. Spray nozzle assembly according to claim 21, the distribution duct openings include respective coupler sleeves which are either blockable by a blind plug or are connectable to a fitting. 24. Spray nozzle assembly according to claim 21, wherein one opening is centered between the valve bores. 25. Spray nozzle assembly according to claim 21, the valve body including a pneumatically actuatable roller membrane or a pneumatically actuatable piston, and a spring, wherein a preload on the spray valve is applied by the spring. 26. Spray nozzle assembly according to claim 25, the valve body including a face surface with a circumferential sealing rim, wherein the sealing-rim is engageable with an O-ring seal of the valve housing. 27. Spray nozzle assembly according to claim 11, wherein the valve housing includes bayonet-lock fittings for attaching the spray-nozzles. 28. Spray-bar arrangement mountable to an agricultural vehicle for spraying liquids, comprising: a least one liquid supply line; fittings, connected to the liquid supply line, having spaced branches; spray nozzle assemblies, comprising: a valve housing having at least two valve bores, wherein each valve bore includes a valve outlet, a distribution duct including a first and a second opening, wherein the distribution duct connects the valve bores, at least two valve bodies located in the valve bores, wherein each valve body is controllably movable independently by pneumatic or electric forces, and spray nozzles, wherein each spray nozzle is connected to a respective one of the valve outlets; wherein the spray nozzle assemblies are connected to the fittings. 29. Spray-bar arrangement according to claim 28, wherein the first and the second openings of the distribution duct are arranged perpendicularly to each other. |
Microarray method for enriching dna fragments from complex mixtures |
A method for the simultaneous, parallel, selective enrichment of different DNA segments which are obtained from different tissues by complex amplifications and have desired individual sequence properties is described. These properties of the DNA fragments, particularly the presence of 5-methylcytosines, can be identified by hybridization on DNA microarrays. The desired DNA fragments are enriched by several repetitions of the operating steps (hybridization, dehybridization and reamplification). The method combines the SELEX method with complex DNA arrays, which are used for the enrichment of DNA fragments. The sequence of the amplificates is then analyzed. |
1. A method for the parallel selective enrichment of many individual, specific PCR fragments from complex fragment mixtures, hereby characterized in that the following steps are conducted: a) the DNA segments are produced by amplification methods that produce complex mixtures of amplificates and thus are simultaneously labeled; b) the amplificates will hybridize to oligomer arrays which bear different oligonucleotides; c) the PCR amplificates hybridized to the oligomer arrays are stripped from the oligonucleotides and serve as the template for a repeated PCR amplification and subsequent hybridization corresponding to steps a) and b); d) step c) is repeated several times; whereby the complexity of the array for each repetition of step c) is reduced. e) the amplificates are identified. 2. The method according to claim 1 [further characterized] in that the amplificates in step c) are stripped from the entire array or from selected partial regions of the array. 3. The method according to claim 1, further characterized in that the PCR amplification methods in step a) are either multiplex PCR reactions or random PCR reactions. 4. The method according to claim 1, further characterized in that in step a), the DNA segments to be amplified are chemically treated. 5. The method according to claim 1, further characterized in that in step a), the nucleic acid sample is repeatedly chemically reacted with a reagent, whereby 5-methylcytosine remains unchanged and cytosine is converted to uracil or another base similar to uracil in its base-[pairing] behavior. 6. The method according to claim 5, further characterized in that the reagent involves a bisulfite (=hydrogen sulfite, disulfite). 7. The method according to one of claims 4, 5 or 6, further characterized in that the chemical treatment is conducted after embedding the DNA in agarose. 8. The method according to one of claims 4, 5 or 6, further characterized in that in the chemical treatment, a reagent that denatures the DNA duplex and/or a radical trap is present. 9. The method according to claim 1, further characterized in that in step a) the segments to be amplified are comprised of RNA and are converted to DNA with reverse transcription. 10. The method according to claim 1, further characterized in that the oligonucleotides in steps b) and c) involve DNA, PNA or LNA oligomers. 11. The method according to claim 1, further characterized in that in steps b) and c) the fragments are alternatively labeled after the PCR amplification or after the reamplification. 12. The method according to claim 1, further characterized in that the PCR amplifications are conducted in the presence of a heat-stable polymerase. 13. The method according to one of the preceding claims, further characterized in that the labeling of the primer oligonucleotides or DNA nucleotide building blocks involves fluorescent dyes with different emission spectra (e.g., Cy3, Cy5, FAM, HEX, TET or ROX) or fluorescent dye combinations in the case of primer oligonucleotides or DNA nucleotide building blocks labeled by energy-transfer fluorescent dye. 14. The method according to one of the preceding claims, further characterized in that the labels are radionuclides. 15. The method according to one of the preceding claims, further characterized in that the labels are removable mass labels which are detected in a mass spectrometer. 16. The method according to one of the preceding claims, further characterized in that molecules that only produce a signal in a further chemical reaction are used for the labeling. 17. The method according to one of the preceding claims, further characterized in that the oligonucleotides are arranged on a solid phase in the form of a rectangular or hexagonal grid. 18. The method according to one of the preceding claims, further characterized in that the labels that are introduced on the amplificates at each position of the solid phase at which an oligonucleotide sequence is found can be identified. 19. The method according to one of the preceding claims, wherein the DNA segments or RNA samples that are converted into DNA with reverse transcription were obtained from a genomic sample, whereby sources for DNA or RNA include, e.g., cell lines, blood, sputum, stool, urine, cerebrospinal fluid, tissue embedded in paraffin, for example, tissue from eyes, intestine, kidney, brain, heart, prostate, lung, breast or liver, histological slides and all possible combinations thereof. 20. Use of a method according to one of the preceding claims for the identification of genes whish are diagnostically relevant for diseases from one of the following categories: cancer diseases; CNS malfunctions, damage or disease; symptoms of aggression or behavioral disturbances; clinical, psychological and social consequences of brain damage; psychotic disturbances and personality disorders; dementia and/or associated syndromes; cardiovascular disease, malfunction and damage; malfunction, damage or disease of the gastrointestinal tract; malfunction, damage or disease of the respiratory system; lesion, inflammation, infection, immunity and/or convalescence; malfunction, damage or disease of the body as a consequence of an abnormality in the development process; malfunction, damage or disease of the skin, the muscles, the connective tissue or the bones; endocrine and metabolic malfunction, damage or disease; headaches or sexual malfunction. 21. Use of a method according to one of the preceding claims for the differentiation of cell types or tissues or for the investigation of cell differentiation. |
Third generation (3g) mobile service over catv network |
A CATV network (141) designed to distribute television and other services in using radio frequencies below a certain frequency (typically 860 HMz) is modified to add a secondary transmission bi-directional capability above this frequency. The secondary bi-directional network (101, 102) is established by adding filters to separate modified mobile-communications frequencies (above 860 MHz) from conventional CATV services (below 860 MHz). Third generation (3G) networks and second generation (2G) networks are together merged with CATV networks. Cable TV networks are used to provide in-building access for 3G and 2G mobile radio terminals, in a mobile radio network. A Cable Mounted Third Generation Module acts as a transmit receive antenna and frequency translator for the 3G signals. |
1. A method for providing bidirectional wireless RF cellular communication through a CATV network, comprising: providing a bypass device at an active point in a CATV network; and communicating frequency shifted wireless RF cellular signals and CATV signals, over the CATV network, between an access point of the CATV network and an indoor termination point of the CATV network; wherein the CATV signals are communicated via the active point and the shifted wireless RF cellular signals are communicated via the bypass device. 2. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 1, further comprising, at the indoor termination point of the CATV network: receiving shifted downlink wireless RF cellular signals from the CATV network; converting the shifted downlink RF cellular signals to original frequency downlink wireless RF cellular signals; outputting the original frequency downlink wireless RF cellular signals to an antenna; receiving original frequency uplink wireless RF signals from the antenna; converting the original frequency uplink wireless RF signals to shifted uplink wireless RF signals; and outputting the shifted uplink wireless RF signals to the CATV network. 3. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 2, further comprising, at the indoor termination point of the CATV network, communicating CATV signals between the CATV network and at least one CATV device by coaxial cable. 4. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 3, wherein the at least one CATV device is one or more of a TV, a set top box, and a cable modem. 5. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 2, further comprising communicating the original frequency wireless RF signals over a common air interface of the cellular network. 6. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 5, wherein the shifted uplink wireless RF signals have a frequency above 905 MHz. 7. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 5, wherein the shifted downlink wireless RF signals have a frequency above 905 MHz. 8. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 5, wherein the original frequency wireless RF signals are shifted to a band higher in frequency than the CATV signals. 9. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 8, wherein the band is 905-1155 Mhz. 10. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 5, wherein the common air interface of the cellular network is a 3G interface. 11. The method for providing bidirectional wireless RF cellular communication through a CATV network according to claim 2, further comprising, at the access point of the CATV network: receiving shifted uplink wireless RF cellular signals from the CATV network; converting the shifted uplink RF cellular signals to original frequency uplink wireless RF cellular signals; outputting the original frequency uplink wireless RF cellular signals to a BTS; receiving original frequency downlink wireless RF signals from the BTS; converting the original frequency downlink wireless RF signals to shifted downlink wireless RF signals; and outputting the shifted downlink wireless RF signals to the CATV network. 12. The method as set forth in claim 11, wherein the bypass device performs the steps of: receiving, as a coupled signal, the CATV signals and the frequency shifted wireless RF cellular signals; differentiating between the CATV signals of the coupled signal and the frequency shifted wireless RF cellular signals of the coupled signal; passing the CATV signals of the coupled signal through the active component of the CATV network; passing only the frequency shifted wireless RF cellular signals of The coupled signal around the active component of the CATV network; and after the passing steps, recombining the CATV signals with the frequency shifted wireless RF cellular signals to provide a signal for further communication over the CATV network. 13. The method as set forth in claim 11, further comprising: injecting, at the access point of the CATV network, one or more pilot continuous wave (CW) frequencies for communication to the indoor termination point; and performing reverse frequency translation at the indoor termination point using the one or more pilot CW frequencies, to convert the shifted downlink RF cellular signals and to convert the original frequency uplink wireless RF signals. 14. The method as set forth in claim 13, wherein the one or more pilot CW frequencies includes only one pilot CW frequency. 15. The method as set forth in claim 13, wherein the one or more pilot CW frequencies includes two pilot CW frequencies. 16. The method as set forth in claim 13, further comprising: using the one or more pilot CW frequencies for creating one or more corresponding local oscillator frequencies; and using the local oscillator frequencies to convert the shifted downlink RF cellular signals and to convert the original frequency uplink wireless RF signals. 17. The method as set forth in claim 16, wherein the creating of the one or more corresponding local oscillator frequencies is performed using non-linear mixing. 18. The method as set forth in claim 13, wherein the bypass device amplifies the one or more pilot CW frequencies in only the direction from the access point toward the indoor termination point. 19. A system for simultaneously communicating Third Generation (3G) cellular traffic and Second Generation (2G) traffic over a cable television (CATV) network, comprising: a Cellular Entrance Module (CEEM) at an access point of the CATV network, receiving original downlink signals, including original 3G downlink signals and original 2G downlink signals, and shifting the original downlink signals to a frequency band higher than television signals of the CATV network to provide shifted cellular signals, including shifted 3G downlink signals and shifted 2G downlink signals; a Cable Mount Third Generation Module (CMTGM) at an indoor termination point of the CATV network, receiving original uplink signals, including original 3G uplink signals and original 2G uplink signals, and shifting the original uplink signals to a frequency band higher than television signals of the CATV network to provide shifted cellular signals, including shifted 3G uplink signals and shifted 2G uplink signals; and a Cellular Transport Module (CETM) at an active component of the CATV network, the shifted cellular signals being communicated over the CATV network between the CEEM and CMTGM via the CETM. 20. The system for simultaneously communicating 3G and 2G traffic according to claim 19, wherein some of the original cellular signals are received using frequencies in accordance with one or more of the UMTS standard and the GSM900 standard. 21. The system for simultaneously communicating 3G and 2G traffic according to claim 19, wherein the frequency band higher than the television signals of the CATV network is a band of 905-1155 Mhz. 22. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 19, wherein the CEEM performs the steps of: receiving downlink CATV signals from the CATV network; the shifting of the original 3G downlink signals to provide the shifted 3G downlink signals and of the original 2G downlink signals to provide the shifted 2G downlink signals; coupling the downlink CATV signals, the shifted 3G downlink signals, and also the shifted 2G downlink signals to provide a coupled downlink signal; transporting the coupled downlink signal through the CATV network; receiving a coupled uplink signal from the CATV network; decoupling the coupled uplink signal to provide uplink CATV signals and the shifted cellular signals; shifting the shifted 3G uplink signals to provide restored 3G uplink signals corresponding in frequency to the original 3G uplink signals, and shifting the shifted 2G uplink signals to provide restored 2G uplink signals corresponding in frequency to the original 2G uplink signals; transporting the uplink CATV signals to the CATV network; and transporting the restored 3G uplink signals and the restored 2G uplink signals to the cellular network. 23. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 22, wherein the CMTGM performs the steps of: receiving uplink CATV signals; the receiving of the original 3G uplink signals and the original 2G uplink signals over a bidirectional antenna; the shifting of the original 3G uplink signals to provide the shifted 3G uplink signals and the shifting of the original 2G uplink signals to provide the shifted 2G uplink signals; coupling the uplink CATV signals, the shifted 3G uplink signals, and the shifted 2G uplink signals to provide a coupled uplink signal; transporting the coupled uplink signal through the CATV network; receiving the coupled-downlink signal from the CATV network; decoupling the coupled downlink signal to provide downlink CATV signals, the shifted 3G downlink signals, and the shifted 2G downlink signals; shifting the shifted 3G downlink signals to provide restored 3G downlink signals corresponding in frequency to the original 3G downlink signals, and shifting the shifted 2G downlink signals to provide restored 2G downlink signals corresponding in frequency to the original 2G downlink signals; transporting the downlink CATV signals to a television signal receiver, and transmitting the restored 3G downlink signals and the restored 2G downlink signals over the bidirectional antenna. 24. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 23, further comprising: injecting, at the CEEM, one or more pilot continuous wave (CW) frequencies in the coupled downlink signal; and performing reverse frequency translation using the one or more pilot CW frequencies, at the CMTCM, to perform the shifting of the shifted 3G and 2G downlink signals and the shifting of the original 3G and 2G uplink signals. 25. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 24, wherein the one or more pilot CW frequencies includes only one pilot CW frequency. 26. The system for simultaneously communicating 3G and 2G traffic as a set forth in claim 24, wherein the one or more pilot CW frequencies includes two pilot CW frequencies. 27. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 24, wherein: the CMTGM includes a local oscillator recreation unit receiving and using the one or more pilot CW frequencies for creating one or more corresponding local oscillator frequencies, and the local oscillator frequencies are used to perform the shifting of the shifted 3G downlink signals to provide the restored 3G downlink signals and the shifting of the shifted 2G downlink signals to provide the restored 2G downlink signals. 28. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 27, wherein the creating of the one or more corresponding local oscillator frequencies is performed using non-linear mixing. 29. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 23, wherein the CETM performs the steps of: receiving, as a coupled signal, one of the coupled uplink signal and the coupled downlink signal; differentiating between CATV signals of the coupled signal and shifted 3G and 2G signals of the coupled signal; passing the CATV signals of the coupled signal through the active component of the CATV network; passing the shifted 3G and 2G signals of the coupled signal around the active component of the CATV network; and after the passing steps, recombining the CATV signals of the coupled signal with the shifted 3G and 2G signals of the coupled signal to provide a signal for transmission over the CATV network. 30. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 29, further comprising: injecting, at the CEEM, one or more pilot continuous wave (CW) frequencies in the coupled downlink signal; and performing reverse frequency translation using the one or more pilot CW frequencies, at the CMTCM, to perform the shifting of the shifted 3G and 2G downlink signals and the shifting of the original 3G and 2G uplink signals. 31. The system for simultaneously communicating 3G and 2G traffic as set forth in claim 21, wherein the CETM amplifies the one or more pilot CW frequencies in only the direction from the CEEM toward the CMTGM. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to a new topology for Third Generation (3G) cellular radio networks like UMTS, CDMA2000 and the like, and a method which improves the in-building coverage and the total available capacity of Third Generation cellular or mobile radio network. In particular, the invention relates to an extension to conventional mobile radio networks using cable-TV or HFC (Hybrid Fiber Coax) networks (referred to as CATV networks, hereafter). To be even more specific, the present invention involves how CATV networks are merged into mobile radio networks to provide improved voice & data services and coverage, while enhancing network capacity; how CATV netowrks are used to provide in-building access for 3G mobile radio terminals, in a mobile radio network; how 3G signals such as those according to the UMTS air interface standard, are combined together with Second Generation (2G) signals such as those according to the GSM900 air interface, and are carried together on the CATV system, without interfering to each other, or the CATV service; and how new applications that result from the synergy of a 3G mobile communication system and terminals and some elements of a CATV system like home TV and/or the set-top box can be realized. 2. Related work. The basic theory by which mobile radio and cellular networks operate is well known. A 3G mobile radio network is an example of such a network. Geographically distributed network access points, each defining cells of the network, characterize cellular radio networks. The geographically distributed network access points are typically referred to as base stations BS or base transceiver stations BTS, and includes transmission and reception equipment for transmitting signals to and receiving signals from mobile radio terminals (MT). Each cell (or sector) is using only part of the total spectrum resources, but the same network resources (either frequency or code), may be used many times in different cells, as long as the cell to cell distance is far enough. This is known as a reuse factor. The cells may be subdivided further, thus defining microcells. Each such microcell provides cellular coverage to a defined (and usually small) area. Microcells are usually limited in terms of their total available capacity. One problem needing to be solved is the inability of present frequency or code reuse techniques (sectorization and cell-area subdivision) to deal with the “third dimension” problem. Cellular networks have no means to deal with the problem of user terminals at higher-than-usual elevations, e.g. upper floors of high-rise office and residential buildings. The overall demand for mobile services had caused cellular network operators to develop an intensive network of BTSs in urban areas. This has improved spectrum utilization (increased network capacity) at ground level, but has aggravated the problem in high-rise buildings where MTs now ‘see’ several BTSs on the same frequency or code. Cells in a cellular radio network are typically connected to a higher-level entity, which may be referred to as a mobile switching center (MSC), which provides certain control and switching functions for all the BTS, connected to it. The MSCs are connected to each other, and also to the public switched telephone network (PSTN), or may themselves have such a PSTN interface. The conventional implementation of a 3G radio network has had some important limitations. In particular, it is necessary in a conventional 3G mobile radio network to build numerous base stations to provide the necessary geographic coverage and to supply enough capacity for high-speed data applications. The 3G base stations require an important amount of real estate, and are very unsightly. Another limitation is that, since cellular towers are expensive, and require real estate, it is economically feasible to include in a network only a limited number of them. Accordingly, the size of cells might be quite large, and it is therefore necessary to equip the mobile radio terminals with the ability to radiate at high-power so as to transmit radio signals strong enough for the geographically dispersed cellular towers to receive. As the cell radius becomes larger, the average effective data rate per user decreases accordingly and the high-speed data service might deteriorate. Yet another limitation to cellular radio networks as conventionally implemented is that the cellular antennas are typically located outside of buildings, even though it would be highly beneficial to provide cellular service inside buildings. The penetration of cellular signals for in-building applications requires high power sites, or additional sites or repeaters to overcome the inherent attenuation inherent with in-building penetration. Because the towers are located outside of buildings, it is difficult for mobile radio terminals to transmit signals strong enough to propagate effectively from inside of the building to outside of the building. Therefore, the use of 3G terminals inside buildings results in reduced data rate and consumes substantial amount of the limited battery time. Yet another limitation of 3G radio networks as conventionally implemented is the inherent limited capacity of each and every BTS to provide voice and data service. This capacity shortage is due to the way the spectrum resources are allocated to each BTS. To provide for reasonable voice and data quality, each BTS can use only a part of the total spectrum resources owned by the cellular operator. Other BTSs could reuse the same part of the spectrum resources as a given BTS, but a pattern of geographic dispersion would have to be respected. This is called a reuse codes pattern for CDMA technologies like UMTS and CDMA2000. One way to mitigate the above-identified disadvantages of 3G networks is by using the access part of a CATV network for the benefit of a cellular radio network. The CATV network is near-ubiquitous, in most urban areas. The delivery of 3G signals directly to the mobile subscriber's premises, by using the CATV network, allows reducing the reuse factor and hence brings an increase of an order of magnitude in the network's available capacity. This is due to the fact that the propagation conditions are greatly improved by using the CATV as an access path inside buildings, instead of transmitting from outdoor towers. The prior approaches for carrying wireless signals over the CATV network include re-arranging or re-packaging the original radio signal to fit into the existing CATV standard frequencies (5-45 MHz and 50-750/860 MHz) and channels. This is typically done by active elements, which up- and down-convert the wireless frequencies to match the known standard CATV operational frequencies in the standard CATV upstream and downstream frequencies. Using the standard CATV channels reduces the available bandwidth of the CATV operators in providing video, data and voice according the common CATV standards like DOCSIS and DVB. Such approaches have all been disadvantageous, however. In particular, if one wishes to re-arrange and re-pack the full UMTS frequency band (1920-1980 MHz, 2110-2170 MHz) into the standard CATV channels, one finds that the UMTS uplink bandwidth (60 MHz) is too large, and hence impossible for the CATV upstream (40 MHz) to carry. Even if smaller UMTS bandwidth were to be carried over the CATV upstream, this would dramatically reduce the scarce upstream CATV resource. Some patent documents representing such disadvantageous approaches are now summarized. U.S. Pat. Nos. 5,802,173 and 5,809,395 (related patents) describe a radiotelephony system in which cellular signals are carried over a CATV network. However, uplink cellular communications are frequency converted to “in the range 5 to 30 Mhz”. Such a conversion is necessary because the CATV network is normally frequency-divided into two bands: a high band which handles downstream transmission (head-end to hub to subscriber) and a low band which handles upstream transmission (subscriber to hum to head end). In other words, any upstream signals or communications over about 45 Mhz are filtered out by the CATV network itself as a part of the normal operation of the network. Under the '173 approach, upstream communications all must be fit into the low band (i.e., in “a portion of the frequency spectrum allocated in the CATV system for upstream communications”). U.S. Pat. No. 5,828,946 describes a CATV based wireless communications scheme. Under the '946 approach, to avoid multiple outdoor cellular receptions from causing noise over the CATV network, only the signals received at a sufficient power level are converted and sent upstream. U.S. Pat. No. 5,822,678 acknowledges that the frequency-divided nature of CATV networks is a problem. In particular, the '678 patent teaches that the limited bandwidth available “within the frequency band of five megahertz to 40 megahertz” poses “a problem with using the cable plant to carry telephonic signals.” To solve this problem, the '678 approach is that “currently existing frequency allocations for cable television are redefined.” That is to say, the division between high and low bands in a CATV network is moved from about 40 Mhz to several hundred megahertz higher. This simplistic approach is highly disadvantageous because it requires replacement of substantial amounts of equipment in any CATV network. Such an expensive approach has not yet been adopted for actual use. U.S. Pat. No. 5,638,422, like the previously mentioned documents, teaches carrying uplink cellular communications “the return path of the CATV system, i.e. 5 to 30 Mhz, for telephone traffic in the return direction.” Furthermore, downlink cellular communications are disadvantageously carried in “the forward spectrum, i.e. 50 to 550 Mhz of the CATV system”. This interferes with CATV signals, and is problematic for the CATV operator, who must move existing programming to other parts of the spectrum to make room for downlink cellular signals. U.S. Pat. No. 6,223,021 teaches how to use programmable remote antenna drivers to provide augmented cellular coverage in outdoor areas. For example, during morning rush hour, the remote antennas are tuned to one frequency set and to another during evening rush hour. Thus, outdoor communications can be flexibly augmented. The remote antenna drivers and their antennas are hung from outdoor CATV cables. The '021 patent does not describe how to solve the problem of limited upstream bandwidth for uplink cellular communications. U.S. Pat. No. 6,192,216 describes how to use a gain tone from remote antenna locations, sent over a CATV network, to determine a proper level of signal at which each remote antenna location should transmit. U.S. Pat. No. 6,122,529 describes the use of outdoor remote antennas and remote antenna drivers to augment an existing cellular coverage area, but only in areas where outdoor cellular antennas provide no coverage. The signal of a given BTS sent to a cellular antenna tower is simulcast over the remote antennas to overcome “blind” areas. U.S. Pat. No. 5,953,670 describes how to use remote antenna drivers as well, but adopts the above-identified approach of sending uplink cellular communications in the low CATV band. |
<SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the invention to overcome the above-identified limitations of the present mobile networks, and the above-identified disadvantages of the related attempts to integrate cellular radio networks with CATV networks. According to one aspect of the invention, there is provided an extension to 3G mobile radio networks whereby a CATV network is enabled to transport mobile radio traffic. According to another aspect of the invention, there is provided a CATV network capable of handling traffic in UMTS and GSM 900 MHz simultaneously without degrading the CATV services or the UMTS and GSM900 services. To achieve the above and other objects of the invention, the CATV network functions as an access element of the 3G or 3G/2G network, namely in its RF propagation-radiation section. According to the system described herein, the capabilities of existing CATV networks are substantially preserved, but the 2G/3G mobile radio terminals do not have to be modified. That is to say, the signals sent according to the radio communications protocol traverse the CATV network on non-utilized CATV frequencies (typically 905-1155 MHz). The radio frequencies and channel structures of the 3G, UMTS, GSM900 and the CATV networks are different. According to the invention, the CATV network is modified so as to permit the propagation of the RF signals of the mobile radio network which are frequency translated to propagate over the CATV system in, e.g., the 905-1155 MHz band. This frequency band (905-1155 MHz) is not used at all by the CATV operators, but it may be used to carry 3G or 2G/3G signals by properly upgrading the CATV infrastructure. A conventional CATV network is a two-way network having a tree and branch topology with cables, amplifiers, signal splitters/combiners and filters. According to one aspect of the invention, the cables and signal splitters/combiners are not modified, but the other elements are. Thus, new components for a CATV system that permit overlaying a multiband bi-directional communication system are described. The modified components allow both types of signals (the CATV up and down signals and the 2G/3G voice+data up and down signals) to be carried by the network simultaneously in a totally independent manner (any cross-coupling can be a source of an unacceptable interference). It is important to note that the cables (fiber and coaxial) used in CATV networks are not severely limited as to bandwidth. Practical CATV networks are bandwidth limited by the bandwidth and signal loading limitations of practical repeater amplifiers. CATV networks now use filters to segment cable spectrum into two bands—one for ‘upstream’ communications and the other for downstream ‘communications’. By adding duplexers and filters to provide additional spectrum segmentation it allows additional amplifiers to handle upstream and downstream cellular network traffic. According to another aspect of the invention, there is provided a Cable Mounted Third Generation Module (CMTGM, see FIG. 4 ). The CMTGM is a component that acts as a transmit/receive antenna and frequency translator for the 3G or 2G/3G signals (the downlink includes controlled attenuation) and as a cable input/output unit for the cable network. Most of the existing CATV video signals are already limited to frequencies under 750 MHz (some CATV networks goes up to 860 MHz) while the 3G and 2G signals operate above this limit and are translated to above this limit. The different types of signals can coexist within the same coaxial cable due to this fact. The CATV network is thus modified in a way that permits the CATV transmissions to be maintained in their original format and frequency assignments. The modifications to the CATV network itself can be made using only linear components such as filters and amplifiers. The modifications are simple, robust and affordable. |
System for charging small amounts on online networks |
The invention relates to a system for charging small amounts of money on online networks. Hereinafter the invention will also be referred to as a “tariffer”. The invention may be employed in the field of online networks, such as the Internet, mobile wireless networks, telephone networks etc. In addition to charging as such the system of the invention also allows control and manipulation of the non-spoken content that is being transferred over the networks. For example, the system of the invention may be used to charge small amounts in the sale of content, information, products and services over networks. |
1. A system for charging small amounts on online networks, characterized in that there is a tariffer (3) between the customer (1) and the vendor (2). 2. A system according to claim 1, characterized in that the tariffer (3) is connected to the customer (1) and to the vendor (2) via bidirectional communication channels. 3. A system according to claim 1, characterized in that the tariffer (3) verifies the identity of the customer (1), retrieves the internet address from its database (4), forwards the request to the vendor (2), receives the content from the vendor (2), verifies the credit balance of the customer (1), sends the content to the customer (1) and registers the concluded transaction into the database (4). 4. A system for charging small amounts on online networks, characterized in that between the customer (1) and the vendor (2) there is a tariffer (5), to which a tariffer (6) is connected. 5. A system according to claim 4, characterized in that the tariffer (5) is connected to the customer (1) and to the vendor (2) via bidirectional communication channels. 6. A system according to claim 4, characterized in that the tariffer (5) is connected to the tariffer (6) via the network. 7. A system according to claim 4, characterized in that the tariffer (5), connected to the tariffer (6) via a secure channel, verifies the identity of the customer (1) and the credit balance of the customer (1), forwards the order to the server of the vendor (2), and notifies the tariffer (6) over a secure channel about the concluded transaction. |
Method for dynamic load management of random access shared communications channels |
A novel method for dynamic load management of random access channels (also known as Aloha channels) in shared communications systems, such as satellite (4), cable, and wireless communications networks is provided. The method provides algorithms and procedures to accurately estimate traffic load offered by multiple distributed terminals (1a, 1b, . . . 1n) into the channel (2). And also provides for regulating traffic so that the channel (2) is not overloaded. The traffic load management algorithms can be done at a central site, such as a Network Control Center (3) or a cable head-end. Alternatively, traffic load management can be done in a distributed manner by all terminals. Traffic regulation is done in a fair manner across all terminals. The algorithms are designed for efficient implementation in software and/or hardware. |
1. A method of sharing bandwidth among a plurality of terminals communicating with a satellite, comprising: (a) designating a random access channel that is available for use by any of said plurality of terminals; (b) estimating a load at said random access channel, wherein each of said terminals receives a control signal indicative of a traffic level of said random access channel, from said satellite and monitors said control signal to determine whether a data message transmitted from said terminals has been received in said satellite; (c) retransmitting said data message from one of said terminals to said satellite if said terminal has not received said control signal within a first predetermined time period; and (d) discarding said data message in said terminal if said terminal has received said control message. 2. The method of claim 1, wherein said control signal includes a blocking factor for said random access channel, said blocking factor being used by said terminals to block a prescribed percentage of traffic from entering said random access channel in accordance with a process performed in at least one of said terminals, and at least one retransmission value. 3. The method of claim 2, wherein one of (a) an exponential backoff strategy is applied to improve said blocking factor on each retransmission; and (b) said terminal selects said random access channel from a series of subsequent frames determined based on a number of usable random access channels in each of said subsequent frames. 4. The method of claim 2, further comprising: each of said terminals receiving and monitoring all of said control signals, each of said control signals comprising information that enables each of said terminals to independently compute a channel loading; and blocking a predetermined amount of traffic from said random access channel to maintain a loading of said random access channel below a prescribed threshold in accordance with said blocking factor, wherein said blocking factor is periodically recalculated. 5. The method of claim 4, further comprising: initializing a value of the blocking factor to zero and an average of said at least one retransmission value to zero; and updating said blocking factor at a second predetermined time period. 6. The method of claim 5, said updating comprising: (a) computing said average of said at least one retransmission number value received over a half of said second predetermined time period, and if said control signal is not received within said half of said second predetermined time period, said average of said at least one retransmission value is set to a previous value of said at least one retransmission value multiplied by 0.95; and (b) computing an average of said blocking factor based on values of said blocking factor received over said half of said second predetermined time period, and if said control signal is not received within said half of said second predetermined time period, said average of said blocking factor is set at a previous value of said blocking factor. 7. The method of claim 6, further comprising: updating said blocking factor based on a subtraction factor modified in accordance with a channel load and a channel input load. 8. The method of claim 7, wherein said channel load is calculated based on 1n (said at least one retransmission value+1) and said channel input load is calculated by dividing said channel load by (said at least one retransmission value+1), and said subtraction factor is calculated by (1−(said blocking factor+said average of said blocking factor divided by two)). 9. The method of claim 8, further comprising modifying said subtraction factor by one of: (a) dividing said subtraction factor by 2 if said channel load is greater than 1; (b) multiplying said subtraction factor by a maximum input load divided by said channel input load if said channel input load is greater than said maximum input load; and (c) adding said subtraction factor to a minimum of (i) 1 and (ii) said maximum input load divided by said channel input load, and divided by 2, and wherein said modified subtraction factor is set to a value greater than zero. 10. The method of claim 9, further comprising updating said modified blocking factor by subtracting said subtraction factor from 1. 11. The method of claim 2, wherein each of said terminals receives and monitors only a corresponding one of said control signals, and said blocking factor is iteratively adjusted. 12. The method of claim 11, further comprising initializing said blocking factor to zero, and when said control message is received, adjusting said blocking factor by one of: (a) if said at least one retransmission value is greater than or equal to a prescribed threshold value indicative of a channel load that is too high, subtracting from a value of 1 a maximum of (i) said blocking factor subtracted from 1 and multiplied by a channel load decreasing factor and (ii) a minimum allowable value for said blocking value subtracted from 1; and (b) if said at least one retransmission value is less than a value of 1 subtracted from a prescribed threshold value, indicative of said channel load being too low, subtracting from a value of 1 a minimum of (i) said blocking factor subtracted from 1 and multiplied by a channel load increasing factor and (ii) a value of 1. 13. The method of claim 11, wherein if said random access channel transmission is not successful, said terminal calculates said blocking factor by subtracting from a value of 1 a maximum of (i) said blocking factor subtracted from 1 and multiplied by a channel load decreasing factor, and (ii) a minimum allowable value for said blocking value subtracted from 1. 14. The method of claim 2, wherein said blocking factor is periodically collected by a network control center (NCC) to perform long-term monitoring of said random access channel and determine whether additional channel capacity is required. 15. The method of claim 2, wherein a network control center (NCC) can perform said random channel load estimation. 16. The method of claim 1, wherein said control signal is one of (i) a control message, and (ii) control information that is piggybacked onto said data message, from which said control information is extracted by said terminals. 17. The method of claim 1, wherein said method is applied to slotted-aloha or unslotted-aloha channels. 18. The method of claim 1, wherein said method is performed in a media access control (MAC) communication layer. 19. A system for sharing bandwidth during communication, comprising: a plurality of terminals configured to wirelessly communicate with one another; a random access channel configured to communicate data messages between any of said plurality of terminals in accordance with an estimated load of said random access channel, wherein each of said terminals receives a control signal indicative of a traffic level of said random access channel from a satellite, and monitors said control signal to determine whether a data message transmitted from said terminals has been received in said satellite. 20. The system of claim 19, wherein said data message is retransmitted from one of said terminals to said satellite if said terminal has not received said control signal within a first predetermined time period, and said data message is discarded in said terminal if said terminal has received said control message. 21. The system of claim 20, wherein said control signal includes a blocking factor for said random access channel, said blocking factor being used by said terminals to block a prescribed percentage of traffic from entering said random access channel in accordance with a process performed in at least one of said terminals, and at least one retransmission value. 22. The system of claim 20, wherein each of said terminals receives and monitors all of said control signals, each of said control signals comprising information that enables each of said terminals to independently compute a channel loading, and a predetermined amount of traffic is blocked from said random access channel to maintain a loading of said random access channel below a prescribed threshold in accordance with said blocking factor that is periodically recalculated. 23. The system of claim 22, further comprising a second predetermined time period during which said blocking factor is updated, wherein a value of the blocking factor is initialized to zero and an average of said at least one retransmission value to zero. 24. The system of claim 23, wherein, said blocking factor is updated by computing said average of said at least one retransmission number value received over a half of said second predetermined time period, and if said control signal is not received within said half of said second predetermined time period, said average of said at least one retransmission value is set to a previous value of said at least one retransmission value multiplied by 0.95, and an average of said blocking factor is computed, based on values of said blocking factor received over said half of said second predetermined time period, and if said control signal is not received within said half of said second predetermined time period, said average of said blocking factor is set to equal a previous value of said blocking factor. 25. The system of claim 24, wherein said blocking factor is updated based on a subtraction factor modified in accordance with a channel load and a channel input load. 26. The system of claim 25, wherein said channel load is calculated based on 1n (said at least one retransmission value+1) and said channel input load is calculated by dividing said channel load by (said at least one retransmission value+1), and said subtraction factor is calculated by (1−(said blocking factor+said average of said blocking factor divided by two)). 27. The system of claim 26, further wherein said subtraction factor is modified by one of: (a) dividing said subtraction factor by 2 if said channel load is greater than 1; (b) multiplying said subtraction factor by a maximum input load divided by said channel input load if said channel input load is greater than said maximum input load; and (c) adding said subtraction factor to a minimum of (i) 1 and (ii) said maximum input load divided by said channel input load, and divided by 2, and wherein said modified subtraction factor is set to a value greater than zero. 28. The system of claim 27, wherein said modified blocking factor is updated by subtracting said subtraction factor from 1. 29. The system of claim 20, wherein each of said terminals receives and monitors only a corresponding one of said control signals, and said blocking factor is configured to be iteratively adjusted. 30. The system of claim 29, wherein said blocking factor is initialized to zero, and when said control message is received, said blocking factor is adjusted by one of: (a) if said at least one retransmission value is greater than or equal to a prescribed threshold value indicative of a channel load that is too high, subtracting from a value of 1 a maximum of (i) said blocking factor subtracted from 1 and multiplied by a channel load decreasing factor and (ii) a minimum allowable value for said blocking value subtracted from 1; and (b) if said at least one retransmission value is less than a value of 1 subtracted from a prescribed threshold value, indicative of said channel load being too low, subtracting from a value of 1 a minimum of (i) said blocking factor subtracted from 1 and multiplied by a channel load increasing factor and (ii) a value of 1. 31. The system of claim 29, wherein if said random access channel transmission is not successful, said terminal calculates said blocking factor by subtracting from a value of 1 a maximum of (i) said blocking factor subtracted from 1 and multiplied by a channel load decreasing factor, and (ii) a minimum allowable value for said blocking value subtracted from 1. 32. The system of claim 19, wherein said control signal is one of (i) a control message, and (ii) control information that is piggybacked onto said data message, from which said control information is extracted by said terminals. 33. The system of claim 19, wherein said system is configured to operate in slotted-aloha or unslotted-aloha channels, and said method is performed in a media access control (MAC) communication layer. |
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a system and method for managing a dynamic load of random access channels. More specifically, the present invention uses various novel methods to estimate traffic in order to prevent overloading of any random access channel. 2. Background of the Invention In the related art, shared-resource communications networks such as satellite, cable, and terrestrial wireless systems use a variety of methods for sharing network bandwidth among multiple distributed terminals. Many related art systems include a related art “random-access” (i.e., Aloha) method as one of the channel access methods. Typically, certain channels among various carriers are designated as random-access channels, and are available for use by any terminal at any time. However, the aforementioned related art computer program and system have various problems and disadvantages. For example, but not by way of limitation, multiple terminals may simultaneously transmit into the random-access channel to cause the bursts to “collide,” and the data is lost. In response, the data is typically retransmitted by the terminals in a manner that minimizes the probability of a re-collision. The aforementioned related art random access channels are typically used for sending signaling and control messages to a central Network Control Center (NCC), as well as for user data traffic, especially if the user traffic is bursty and intermittent. If the input traffic load exceeds a certain threshold, then the useful throughput of the random access channel declines, due to the aforementioned related art problem of colliding bursts that are retransmitted, thus further increasing the channel load. If the related art random-access slots are time-aligned (i.e., slotted aloha), then the maximum throughput of such channels is 36% of channel capacity. However, if the random access time slots are not time-aligned, then the maximum throughput is only 18%. Also, related art systems with many terminals require a mechanism to estimate the load into the random-access channel, so that traffic can be reduced when the load exceeds a prescribed threshold. Related art approaches to this issue have used a centralized method, where the central NCC gathers channel load information and distributes estimated loading factors to terminals. For example, but not by way of limitation, related art approaches have used collision detection hardware techniques to estimate channel loading, or information from the messages themselves that is indicative of whether the message is an original message or a retransmission. However, the aforementioned related art approaches have various problems and disadvantages. For example, but not by way of limitation, the related art approaches work only for networks where the contention channels can be monitored by the NCC. However, in many networks such an arrangement is not possible. Networks that contain a large number of terminals require considerable processing power at the NCC to monitor the large number of contention channels. Further, a related art network may contain contention channels for direct terminal-to-terminal traffic, and as a result, the NCC may not have access to those channels. Also, the related art centralized approach requires feedback to the terminal indicating whether a message was receive correctly. In centralized systems, the NCC provides feedback when a message is correctly received, whereas collision of a message is indicated by the lack of feedback within a certain timeout period. |
<SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to overcome at least the aforementioned problems and disadvantages of the related art system. It is another object of the present invention to provide a system and method for use in networks with centralized as well as distributed channel monitoring and control. It is also an object of the present invention to provide a distributed approach in a satellite network with on-board processing as an example of a specific implementation and description. To achieve at least the foregoing objects, a method of sharing bandwidth among a plurality of terminals communicating with a satellite is provided, comprising (a) designating a random access channel that is available for use by any of the plurality of terminals; (b) estimating a load at the random access channel, wherein each of the terminals receives a control signal indicative of a traffic level of the random access channel, from the satellite and monitors the control signal to determine whether a data message transmitted from the terminals has been received in the satellite; (c) retransmitting the data message from one of the terminals to the satellite if the terminal has not received the control signal within a first predetermined time period; (d) discarding the message in the terminal if the satellite has received the message. Additionally, a system for sharing bandwidth during communication is provided, comprising a plurality of terminals configured to wirelessly communicate with one another, and a random access channel configured to communicate data messages between any of the plurality of terminals in accordance with an estimated load of the random access channel, wherein each of the terminals receives a control signal indicative of a traffic level of the random access channel from a satellite, and monitors the control signal to determine whether a data message transmitted from the terminals has been received in the satellite. |
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