A platform and method for mimicking the environment within a cell is provided. The platform includes a microfluidic device defining a chamber. At least one hydrogel post is positioned within the chamber of the microfluidic device. Each hydrogel post defines a corresponding pore for receiving a first molecule therein. Second molecules are introduced into the pores of the hydrogel posts and the interactions between the first and second molecules are observed.

The various events that occur inside a cell, such as metabolism and signal transduction, are orchestrated at the molecular level. For example, in signal transduction, a cascade of biomolecular interactions is initiated. These interactions include (but are not limited to) phosphorylation, binding and transportation of molecules. The effects of these interactions are often transmitted to the nucleus wherein the gene expression pattern is modified based on the signal. In metabolism (e.g., glycolysis), many enzymatic steps occur in sequence. Moreover, activation of enzymes is often controlled by interaction of the enzymes with other molecules (activators). Thus, these enzymatic steps also involve synchronization in terms of movement of molecules, binding and chemical modification.
A cell contains a large number of macromolecules (proteins, nucleic acids, polysaccharides), small molecules (glucose), ions and water. A cell also contains a network of protein filaments, referred to as the cytoskeleton, which is involved in a number of cell processes, in addition to providing mechanical support and defining the structure of the cell. The cytoskeleton is formed from protein filaments (e.g., actin). It can be appreciated that accommodating all these materials in a small volume results in a crowded environment within the cell. Moreover, the protein filaments create confined volumes (or compartments) inside the cell.
In order to study the transportation of molecules inside the cell and organelles such as mitochondria, fluorescent-based experiments have been performed. In these experiments, fluorescent probes (e.g., dextrans or ficolls) are micro-injected into the cytoplasm and the diffusion is studied by measuring the time taken for recovery of fluorescence after photo-bleaching a small area. These experiments reveal that for non-interacting probes (e.g., dextran), transportation is progressively diminished as the molecular weight of the probe is increased. Based on these observations, researchers describe the environment inside the cytoplasm to be "sieving." This effect is thought to be largely caused by the structure of the cytoskeleton. For probes or molecules that can interact with biomolecules inside the cytoplasm (e.g., DNA), the mobility is more complex. The interaction with molecules leads to "traps" whose strength is related to the specificity of the interaction; i.e., stronger interaction leads to bigger traps. These traps or barriers result in anomalies in diffusion that have been observed both in cytoplasm and in organelles. Moreover, when the cell is depleted of Adenosine Triphoshate (ATP), the mobility of glycolytic enzyme is reduced; thus suggesting that mobility of molecules is affected by the metabolic state of the cell. A common observation of the cytoplasm environment is that the degree of crowding is not consistent. Diffusion of non-interacting probes indicates that certain regions are densely packed compared to other regions. Furthermore, it has been reported that the density of actin filaments (part of the cytoskeleton) is dynamic.
Currently, most biochemical interactions are studied in solution phase wherein the concentration of the molecules is dilute. Given the complexity of the cellular environment, comparing results from dilute solution studies to the actual interactions inside the cell is difficult. For example, side effects of drugs that are designed to interact with specific biomolecules in solution phase may be a result of variations in interaction due to the different environment in the cell. On the other extreme, studies performed inside cells are often difficult to characterize due to multiplicity of interactions and variations between cells. Therefore, there exists a need for a model environment that is simpler than cells yet captures the basic characteristics of the cellular nano-environment such as the presence of charge, crowding, water content and structure. It can be appreciated that such a model environment would aid in the development of effective inhibitory molecules (e.g., drugs) and in understanding the basic mechanisms of cell signaling and behavior.
Therefore, it is a primary object and feature of the present invention to provide a microfluidic-based cell mimic platform for biomolecular studies and a method of mimicking the environment within a cell utilizing the same.
It is a further object and feature of the present invention to provide a microfluidic-based cell mimic platform and a method of mimicking the environment within a cell utilizing the same that more accurately predicts in vivo interactions via in vitro experiments than prior platforms and methods.
It is a still further object and feature of the present invention to provide a microfluidic-based cell mimic platform and a method of mimicking the environment within a cell utilizing the same that are simple and that easily capture the basic characteristics of the cellular nano-environment.
In accordance with the present invention, a platform is provided for mimicking the environment within a cell. The platform includes a microfluidic device defining a chamber and a first hydrogel post is positioned within the chamber. The first hydrogel post defines a first pore therein. A biomolecule is received in the first pore in the post.
The platform may also include a second hydrogel post within the chamber of the microfluidic device. The second hydrogel post includes a second polymer chain defining a second pore. The first pore has a first cross sectional area and the second pore has a second cross sectional area. The second cross sectional area is less than the first cross sectional area. Alternatively, the first hydrogel post may include the second pore having the second cross sectional area. The first hydrogel post may be one of an array of hydrogel posts with the chamber of the microfluidic device. Each hydrogel post of the array of hydrogel posts has a pore therein.
The first hydrogel post is formed from a plurality of cross-linked polymer chains. In addition, a crowding agent may be received in the first pore of the first hydrogel post. The crowding agent is formed from a soluble material captured in the first hydrogel post. The platform may also include a flow of reagent flowing through the chamber of the microfluidic device. The reagent interacts with the biomolecule in the first pore.
In accordance with a further aspect of the present invention, a method is provided for mimicking a nano-environment within a cell to study the interaction between molecules. The method includes the steps of providing a micro device that defines a chamber therein and positioning a first hydrogel post within the chamber of the micro device. The first hydrogel post defines a first pore therein. First and second molecules are deposited in the first pore in the first hydrogel post. Thereafter, the interaction of the first and second molecules in the first pore is observed.
The step of depositing the first molecule in the first pore in the first hydrogel post includes the step of introducing a stream of fluid having the first molecule into the chamber. The first molecule is allowed to diffuse into the first pore. It is contemplated to vary the volume of the first pore. The method includes the additional steps of fabricating the first hydrogel post from a monomer, a cross-linker and a photo-initiator and positioning a second hydrogel post within the chamber of the micro device. The second hydrogel post defines a second pore therein. In a first embodiment, the first pore has a first volume and the second pore has a second volume wherein the second volume is less than the first volume. Alternatively, the first hydrogel post defines the second pore wherein the first pore has a first volume and the second pore has a second volume. The second volume is less than the first volume. In a still further embodiment, the first hydrogel post may be one of an array of hydrogel posts in the chamber.
In accordance with a still further aspect of the present invention, a method is provided of mimicking the environment within a cell. The method includes the steps of providing a chamber and positioning a first post within the chamber. The first post defines a first pore therein. First and second molecules are deposited in the first pore. Thereafter, the interaction of the first and second molecules in the first pore are monitored.
The step of depositing the first molecule in the first pore in the first post includes the step of introducing a stream of fluid having the first molecule into the chamber. The first molecule is allowed to diffuse into the first pore. The step of depositing the second molecule in the first pore in the first post includes the step of introducing a second stream of fluid having the second molecule into the chamber. The second molecule is allowed to diffuse into the first pore. It is contemplated to vary the volume of the first pore. The method includes the additional steps of fabricating the first post from a monomer, a cross-linker and a photo-initiator and positioning a second post within the chamber of the micro device. The second post defines a second pore therein. In a first embodiment, the first pore has a first volume and the second pore has a second volume wherein the second volume is less than the first volume. Alternatively, the first post defines the second pore wherein the first pore has a first volume and the second pore has a second volume. The second volume is less than the first volume. In a still further embodiment, the first post may be one of an array of posts in the chamber.


The invention permits the transfer between two containers of an object without the latter being in contact with the atmosphere around the containers. The system comprises two doors (12, 22) joined tightly to one another in such a way that the outer faces (13, 23) of these doors are positioned facing one another during opening, e.g. by winding the same around a drum (21). These doors are constituted by two flexible curtains sliding in lateral carriages. The system is particularly applicable to the production of semiconductor wafers or slices in an ultraclean atmosphere.

1. Field of the Invention
The present invention relates to the field of working and transporting objects in ultraclean atmospheres. It more particularly relates to the microelectronics industry.
2. Description of Related Art
In certain industries, such as microelectronics, some operations such as the preparation of silicon wafers must be carried out in a substantially impurity or dust-free atmosphere, i.e. in so-called white rooms. This is obtained by ventilating the rooms with air which has been filtered by absolute filters, i.e. those stopping even the finest dust.
It is also possible to transport or store silicon wafers in containers within which there is such an ultraclean atmosphere without the atmosphere of the rooms in which the containers are located being ultraclean. Therefore, these containers must be tight with respect to the dust in the said rooms.
Moreover, it is often necessary to transfer one or more silicon wafers between individual containers, e.g. from a storage container to a transportation container. The opening of the doors of the containers and the passage of the object from one container to the other cause problems of sealing with respect to the ultraclean atmosphere. Part of the problem could be solved by coupling together the two ultraclean containers prior to the opening of the two doors. However, like all the outer faces of the containers, the door has previously been in contact with the atmosphere prevailing in the room. Therefore, the coupling together of the two containers involves confining within the ultraclean volume defined by the interior of the two containers of the door and its polluted outer face.
The aim of the invention is to obviate this disadvantage by proposing a system of coupling together the two containers and opening the container doors without polluting the two containers by the outer face of the two doors.

System of doors between two mobile containers, particularly two ultraclean containers


Systems, methods, and non-transitory computer-readable media are disclosed for selectively rendering augmented reality content based on predictions regarding a user's ability to visually process the augmented reality content. For instance, the disclosed systems can identify eye tracking information for a user at an initial time. Moreover, the disclosed systems can predict a change in an ability of the user to visually process an augmented reality element at a future time based on the eye tracking information. Additionally, the disclosed systems can selectively render the augmented reality element at the future time based on the predicted change in the ability of the user to visually process the augmented reality element.

The present disclosure generally relates to augmented reality (AR) systems. Augmented reality systems and environments allow a user to directly or indirectly view a real world environment augmented by generated sensory input, which may be super-imposed on the real world environment. Sensory input can be any form of media, such as sound, video, graphics, etc. Because AR systems allow for users to continue to engage with their real world environments in addition to a generated one, users may have less tolerance for large AR devices, as opposed to a virtual reality (VR) system in which the user is typically immersed in a fully generated environment.
However, the reduced form factor of AR devices produces challenges for providing sufficient power and computation. For example, AR devices often sacrifice battery and computation power to minimize weight and heat generation, resulting in devices with short battery life and reduced AR capabilities. In addition, the heat generated by both the battery and processor may be uncomfortable to a user, especially since the reduced form factor has limited surface area over which to diffuse the generated heat.
These along with other problems and issues exist with regard to conventional digital graphics systems.

This patent is subject to a terminal disclaimer.

Reducing head mounted display power consumption and heat generation through predictive rendering of content


The present invention provides for the connection of a pressure balanced stab and a manifold in which offsetting forces maintained on the stab allow it to remain in an inserted state within the manifold without the use of a significant amount of force to maintain the connection. The offsetting forces are contained within the stab through the use of C-ring seals on the stab, which are activated by a downward force created by an actuator. The compression of the C-rings is delayed until insertion is complete, therefore allowing an installation which does not damage the seals. The O-ring designs, used in prior pressure balanced stabs, are likely to be damaged upon insertion of the stab into the receptacle. The damage to the O-ring seals takes place when the O-ring, partially protruding from the stab, makes contact with the surface of the receptacle in such a manner that causes the O-ring seal to tear or become manipulated in a way that creates an ineffective seal. The preferred embodiment allows for activation of the C-ring seal to take place following insertion of the stab within the receptacle and therefore the C-ring does not encounter interference from the surface of the receptacle until it is activated. In addition to the prevention of damage to the C-ring seal, the preferred embodiment allows for the seal to withstand greater pressure than prior O-ring designs.

In subsea operations such as oil and gas exploration it is common to utilize a stab containing a flowline for charging and discharging of liquids within a manifold. Various engagement mechanisms are used in connecting and maintaining the connection between the stab and the manifold. Seals are placed on the stab and are used to maintain the connection between the stab and the manifold. The seals are positioned within the stab in such a manner that the hydrostatic pressure maintained in the lower end of the stab exerts an upward force while the hydrostatic pressure at the upper end of the stab exerts an equal downward force. A lateral outlet port in which fluids can be discharged is provided between the seals. The offsetting forces create a stab that remains as positioned within the manifold.
In a conventional stab assembly the seals consist of O-rings placed on the stab. Once the stab is submerged, these seals facilitate the connection of the stab to the manifold. The disadvantage with the O-ring seal design and other commonly used seals is that during insertion of the stab into the manifold the seals may become damaged, which would result in receptacle leakage.
It is therefore an object of the present invention to provide a unique sealing arrangement which allows dependable sealing at much higher pressures, i.e. greater than 15,000 pounds per square inch, than the seals used in hydraulic stabs.

Engageable metal seal pressure balanced stab


A method of forming a trench in a semiconductor substrate includes a step of converting the cross section of the upper portion of the trench from octagonal to rectangular, so that sensitivity to alignment errors between the trench lithography and the active area lithography is reduced. Applications include a vertical transistor that becomes insensitive to misalignment between the trench and the litho for the active area, in particular a DRAM cell with a vertical transistor.

The field of the invention relates to trenches formed in a substrate, and more particularly to trench memory devices having a vertical transistor above a trench capacitor.
FIG. 8B illustrates in simplified form a cross section of a pair of DRAM cells formed in substrate 10 and having a P-well 15. A trench has been etched into the substrate and capacitor 100 has been formed in the lower portion, with dielectric 107 and center electrode 110. In the upper portion of the trench, a vertical transistor 200 has been formed, with buried strap 127 as the lower electrode.
In the course of etching a deep trench in a silicon substrate, a conventional configuration of orienting the trench in the substrate is the <100> configuration, in which the long axis of the oval trenches are printed at the wafer surface are parallel to a <100> crystallographic direction of the substrate (diagramed in FIG. 8A). In this configuration, the formed trench assumes a square shape in the bottom, as shown in FIG. 9A; an oval shape at wafer surface, as shown in FIG. 9C; and an octagon shape in the upper portion of the trench, as shown in FIG. 9B. The change of trench shape at different depth is due to the fact that etch rates are different at different crystallographic orientations. Specifically, the {100} surfaces of the silicon are etched at a greater rate than the {110} surfaces.
The <100> configuration is conventionally chosen because the differential etching along the crystal planes produces a square cross section that packs together tightly, even after the step of bottle etching, so that the capacitance can be maximized by using the bottle etch step, without having an excessive risk of trench merging. However, the octagonal cross section of the upper trench where the vertical transistor is formed matches poorly with the stripe that defines the active area (AA) by defining the isolation structures that separate devices and structures on the wafer surface.
FIG. 9B shows AA strips 910 that meet the octagons 920 that represent the trench cross section such that the corners of the octagons are at the trench-AA intersection. This results in the undesired variation of vertical transistor characteristics such as threshold voltage (Vt) when the trench-AA intersection is located slightly away from the corner or at the corner of the octagon.
Thus, the requirement of getting the highest capacitance in the trench and avoiding shorts between capacitors conflicts with the need for a tight alignment tolerance between the trench and the AA level.
The art could benefit from a trench capacitor—vertical transistor process that preserves tight tolerance between the trench and the active area.

Vertical device with optimal trench shape

International Business Machines Corporation


First polysilicon (poly-1) is deposited into deep trenches that have been formed in a substrate. A first polysilicon polishing process is performed to planarize the exposed surfaces of the poly-1 so that the surfaces are flush with adjacent surfaces. Then, shallow trenches are formed in the substrate between the deep trenches, and second polysilicon (poly-2) is deposited into the shallow trenches. A second polysilicon polishing process is performed to planarize the exposed surface of the poly-2 so that the surface is flush with adjacent surfaces. Metal contacts to the poly-1 and the poly-2 are then formed.

To conserve power, it is important to reduce power losses in transistors. In a metal oxide semiconductor field effect transistor (MOSFET) device, power losses can be reduced by reducing the device's drain-to-source on-resistance.
In order to achieve a high breakdown voltage in a MOS device, the epitaxial (epi) layer and/or resistivity can be increased, but this can detrimentally affect on-resistance. To alleviate that problem, a modulated electric field that is vertical to the direction of the current when the device is off can be introduced. A modulated electric field in the drift region increases the breakdown voltage and allows for higher doping concentration for a given breakdown voltage relative to a more conventional MOS device. One way to generate such an electric field is to include a "split gate" alongside the drift region. In a split gate structure, a MOS structure (e.g., trench) is created alongside the drift region. A shielded polysilicon (poly) region, which is connected to the source, is placed under the gate poly inside the trench, and the gate structure is built on top of the trench. Split gate structures offer a number of advantages, including better switching and breakdown voltage and lower on-resistance, but are difficult to manufacture.

Structures and methods of fabricating dual gate devices


A method of molding a ceramic vessel includes compressing a water-soluble powder, suspending the compressed powder shape in a mold, injecting a ceramic molding mixture into the mold, and dissolving the compressed powder by flushing the vessel with water. A core for making an arc discharge vessel that has a discharge chamber and two capillaries includes a molded core of the water-soluble powder having a shape of the discharge chamber, and preferably two capillary-forming pins extending from the molded core. An apparatus for removing the molded core that includes a water reservoir that preferably flushes water through the vessel and dissolves molded core.

The present invention is directed to the manufacture of ceramic vessels, such as arc discharge vessels for metal halide lamps. As illustrated in FIG. 1, a ceramic vessel 10 for a metal halide lamp has a hollow middle part 12 and may have two hollow capillaries 14 that extend from the middle part. In an arc discharge vessel, the hollow middle part 12 is the arc discharge chamber and the capillaries 14 sealably receive electrodes that extend into the arc discharge chamber. In lamps, the vessel 10 is made of a ceramic material that is transparent or translucent, such as aluminum oxide or aluminum oxynitride.
A common method of molding such vessels has been to form the vessel from several separate parts. For example, a cylindrical central portion may be connected to two capillary end portions by the assembly of three to five individual pieces of ceramic in a process that requires multiple firings.
In lamps, vessel shape is a factor in lamp performance. One improvement is a "bulgy" design that has an elliptical shape, such as two hemispheres separated by a short cylindrical portion. The common method described above is not suitable to make this vessel shape. Bulgy vessels have been made with a two-piece injection molding process in which two half parts are separately molded and then welded together, e.g., as in U.S. Pat. No. 6,620,272 to Zaslavsky et al. While vessels produced with this method are generally acceptable, they have a visible center seam 5 as shown in FIG. 1.
Another known method of molding a one-piece vessel is with a gel casting process that uses a core of a thermoplastic material that is removed by melting. In this method, a fluid suspension is added to the space between an exterior mold and the molded core. The fluid suspension includes a ceramic powder suspended in a liquid medium containing a cross-linking chemical. An activator or catalyst is added to the fluid suspension just prior to filling the mold to initiate the cross-linking process, and the suspension solidifies at completion of the cross-linking. The formed vessel is removed from the exterior mold and then heated to melt the core that drains out of the vessel through an opening in the vessel wall.
A problem with this method has been the residence time needed for the cross-linking to form the vessel, which can vary from several minutes to hours depending on the materials selected. Longer residence times require more molds and more space for high volume production.

Core for molding a ceramic discharge vessel


In the apparatus, under the action of the explosion of a mixture of air and gas in a chamber closed by a chamber sleeve tube and a cage when the apparatus is pressed against something, a piston is propelled in a cylinder to drive an element. The chamber sleeve tube and the cylinder are arranged in such a way that, as the apparatus is closed, the chamber sleeve tube comes into abutment against the cylinder.

In such an apparatus, a piston is mounted so that it can move in a cylinder where it can be propelled, by the explosion of a mixture of air and a fuel gas injected, from a cartridge, into a combustion chamber and to drive an element, for example a fastener (a nail or an insert) or some other anchor. Apart form the bearing-against-something safety feature, that prevents any firing when the apparatus is not pressed against a receiving material, this kind of apparatus has a member, known as a cage, which, when the apparatus is pressed against something, and by way of a feeler that may be a moving insert guide, pushes a chamber sleeve tube back until it comes into abutment against the cylinder head that carries the spark plug intended to cause the explosion, so as to close the combustion chamber thus formed by this sleeve tube, the cylinder head and the crown of the piston. The cage and the sleeve tube may be connected to one another by screwing. Furthermore, the retreat of the cage is performed against the action of a return spring, to return the apparatus to the open position, also bearing against the piston cylinder.
Because the combustion chamber bears against the cylinder head, stressful pressures are exerted on the cylinder head when such an apparatus is operating, particularly since the surface portions of the cylinder head and of the cylinder face one another. Even if, in other apparatuses, these detrimental pressures are no longer exerted on the cylinder head, they are transferred to the cage, which is not necessarily any better.

Gas-operated apparatus for driving an element using a piston

Abstract: The invention can well be applied to nail guns and other staplers.

Societe de Prospection et d'Inventions Techniques Spit


A backing film for incorporation as a backing layer in a resilient floor covering or a floor tile having at least two laminae and a method for making such a backing layer whereby wastage is reduced when the color of the upper lamina is changed. Where there are two backing films having two or three laminae making up the backing layer the intermediately colored film resulting from a change in the color of the upper lamina can be utilized without further processing on the second backing film where color is not essential. Where there are three laminae making up a backing film the desired color is introduced and established in the bottom lamina before the supply of the original color to the upper lamina is stopped. The film can then be turned over for use with the former bottom lamina becoming the upper lamina.

Resilient floor coverings are well known and are described for example in an article entitled "Flooring Materials" in Encyclopaedia of Polymer Science and Engineering, Wiley-Interscience, Volume 7 (1987), pages 233-247. Such floor coverings, as described in that article, are composite materials which comprise a transparent or translucent wear (upper) layer, often a decorative (intermediate) layer such as a printed patterned layer, and one or more backing (lower) layers. The composition of each layer in such composite laminate floor coverings is chosen to provide the desired balance of physical properties, both in that layer and in the whole composite laminate. Thus, for example, the properties of all the layers are desirably balanced so as to avoid curl.
The backing layer nearest the wear layer commonly contains one or more colored pigments and is commonly called the face ply. If no intermediate decorative layer is present, then the face ply itself provides the desired decorative appearance of the floor covering. If the floor covering includes a printed patterned layer, then the face ply serves to enhance the appearance of the printed patterned layer as seen through the wear layer. The face ply is often of a bright color, for example white, although it may be of a neutral color such as black. The other backing layers more remote from the wear layer commonly contain carbon black to provide a neutral opaque background behind the face ply. All the backing layers, including the face ply, commonly contain fillers such as calcium carbonate, hydrated aluminium oxide, kaolin or other suitable particulate or fibrous mineral fillers.
Films for incorporation in resilient floor coverings may be made by extrusion of suitable polymer compositions. For example, the backing layers including the face ply may be made by extrusion of polymer compositions based on ethylene/vinyl acetate or ethylene/alkyl acrylate, for example methyl or butyl acrylate, copolymers. It is often desirable to make differently-colored face plies at different times on a single extruder. Steps must therefore be taken to minimise the production of waste film at changeover. The extruder may be stopped, emptied and cleaned, but this is laborious and involves loss of production from the extruder whilst this is done. Alternatively, the color of the polymer composition fed to the extruder may be changed while the extruder continues to run, and waste film of intermediate color may be collected until the extruder has been flushed. This waste film can be shredded and used (with the addition of carbon black, if desired) for the manufacture of black backing layers. Nevertheless, this procedure requires additional operations to be carried out, and these operations may result in some degradation of properties of the thusly recycled polymer composition.
It is an object of the present invention to provide improved methods of manufacturing a film for incorporation as backing layer in resilient floor coverings, in particular a film which includes a face ply and to reduce loss of production when the color of a face ply is changed.


A non-invasive eye oximeter which monitors the arteriovenous oxygen difference. The optic disc region of the ocular fundus is illuminated with three or more wavelengths of light focused in approximately the same area. One of the light sources serves as a tracking beam which, through reflectance spectrophotometry, is used to determine when the tracking light beam is focused upon the optic disc. The scanning light beams are primarily focused within the boundary of the tracking beam. The intensity of light reflected from retinal venules and arterioles is detected, and the arteriovenous oxygen difference is determined.

It is necessary to determine arteriovenous oxygen difference, or a-vO.sub.2 in order to determine cardiac output, which is an important physiologic parameter, during surgical procedures, post-operative monitoring and the management of critically ill patients. Cardiac output, or C.O. is equal to oxygen consumption, VO.sub.2, divided by arteriovenous oxygen difference, a-vO.sub.2. The relationship can be stated algebraically as: ##EQU1##
While there are non-invasive methods for determining oxygen consumption, VO.sub.2, at the present time, there are only invasive methods for determining arteriovenous oxygen
difference, a-vO.sub.2. The non-invasive method for determining arteriovenous oxygen difference of the present method would thus allow cardiac output to be determined without the need for invasive procedures with the attendant risks of infection, bleeding and other trauma. The present invention utilizes the optic disc as the monitoring site. This site was chosen because it has the most accessible peripheral arterioles and venules for non-invasive monitoring.
Prior art using the eye to measure oxygen saturation focused on different portions of the fundus. In U.S. Pat. No. 4,485,820, Flower disclosed a scleral contact lens with a fiberoptic apparatus which measured the hemoglobin saturation of the choroidal arteries. This corresponded to the arterial saturation in, primarily, premature infants. Rather than focusing on the optic disc, Flower utilized the capacity of the eye to serve as an integrating sphere, thereby providing the largest possible surface area to monitor choroidal (arterial) oxygen saturation. Also, Flower did not determine venous oxygen saturation and, therefore, did not determine arteriovenous oxygen difference.
In U.S. Pat. No. 4,877,322, Hill described the use of a collimated beam of light to view specific areas of the fundus, such as the macula, or the optic disc. The ratio of oxyhemoglobin to reduced hemoglobin of these particular areas allows the physician to detect macular degeneration or glaucoma at its early stages.
Novack, in U.S. Pat. No. 4,922,919, measures the oxidative metabolism in ocular tissue by taking advantage of the absorption peak of cytochrome c oxidase. Novack primarily employs an optical probe, which penetrates the ocular body. While Novack describes an alternative apparatus which consists of a contact lens, and subsequently mentions that the invention can also measure desaturated hemoglobin, arteriovenous oxygen difference is not determined. Additionally, Novack does not specifically target the optic disc.
In "The Choroidal Eye Oximeter: An Instrument for Measuring Oxygen Saturation of Choroidal Blood in vivo," IEEE Trans. Biomedical Engineering, Vol. BME-22, No. 3, pp. 183-193, 1975, Laing, R. A., et al., the authors make no distinction between the oxygen saturation of choroidal venous and arterial blood.
As mentioned above, arteriovenous oxygen difference, is a highly useful physiologic parameter. Shepherd et al. designed a spectrophotometer which could analyze the arteriovenous oxygen difference, when venous and arterial blood were pumped from dogs into cuvettes. See, Shepherd, A. P. and C. G. Burgar, "A solid-State Arteriovenous Oxygen Difference Analyzer for Flowing Whole Blood," Amer. J. Physiol., Vol. 232, pp. H437-H440, 1977. More recently, Suga et al. devised an instrument which measures not only arteriovenous oxygen content difference, but arterial and venous oxyhemoglobin saturation as well. See, Suga, Hiroyuki, et al., "Arteriovenous Oximeter for O.sub.2 Content Difference, O.sub.2 Saturation and Hemoglobin Content", Amer. J. Physiol. 257 (Heart Circ. Physiol. 26): pp. H1712-H1716, 1989. This is an invasive technique that requires cannulation of the subject's artery and vein.
In U.S. Pat. No. 4,305,398, Sawa discloses an eye oximeter for measuring the oxygen saturation of the blood in the fundus of the eye. Sawa recognized that the problem with this type of analysis is the difficulty in discriminating the reflection or absorption of light by the eye fundus blood from the reflection or absorption of light by the various cell layers in the eye fundus. Sawa's approach to solving this problem utilized the phenomenon in which visual pigments in photoreceptor cells may become transparent upon being illuminated by light.
In U.S. Pat. No. 3,565,529, Guyton, discloses a device for providing continuous measurement of the difference between the amount of oxygen in arterial and venous blood. Guyton disclosed an analyzer which determines the oxygen difference in arterial and venous blood. Light of a narrow wavelength is passed through venous blood and arterial blood that has been pumped into cuvettes. This required catheterization of an artery and a vein in order to pump blood through the cuvette and back into the subject's blood stream.
It is known that when red-free light (e.g. green) is shone into the optic fundus, the optic disc, which is free of photoreceptors, appears brighter than the surrounding fundus background. In fact, with the appropriate wavelength of green light, the retinal vasculature appears almost black. See, Paton, D., et al., In: Introduction to Ophthalmoscopy, Edited by B. A. Thomas, Kalamazoo, Mich.: Upjohn Company, 1979, p. 10. Additionally, the maximum absorption wavelength for mammalian rods is 500 nm, and for cones is 562 nm. See, Sharkov, A. V. and Yu A. Matveets, "Ultrafast Processes to Rhodopsins", In: Laser Picosecond Spectroscopy and Photochemistry of Biomolecules, 1987, p. 58.
It has been demonstrated that determination of oxyhemoglobin saturation values can be achieved in vessels as small as 12 microns diameter, using reflectance spectrophotometry. See, Fenton, B. M., et al., "Determination of Microvascular Hemoglobin saturations using Cryospectrophotometry," Amer. J. Physio. 259 (Heart Circ. Physiol. 28): pp. H1912-H1920, 1990. Also, Fenton states that the hematocrit for microvasculature tends to vary from one vessel to another. However, the arteriovenous oxygen difference is independent of hematocrit, at least up to a hematocrit value of 60 to 70%. See, Steinke, J. M., et al., "Role of Light Scattering in Spectrophotometric Measurements of Arteriovenous Oxygen Difference," IEEE TRANS. BIOMEDICAL ENGINEERING, Vol. BME-33, No. 8, pp. 729-734, 1986.
Accordingly, it is an object of the present invention to provide a method and apparatus which can detect arterial and venous oxyhemoglobin saturation in vivo, non-invasively, and atraumatically.
It is another object of the present invention to consistently determine and distinguish between venous and arterial oxyhemoglobin saturation by scanning the optic disc, thereby allowing a determination of the arteriovenous oxygen difference.
It is yet a further object of the present invention to provide a method and apparatus for scanning the optic disc region of the fundus in a linear or curvilinear pattern, thus allowing more than one venule and arteriole pair to be analyzed.
Still another object of the present invention is to provide an apparatus with the capability of sensing the optic disc region of the fundus and accordingly monitoring the optic disc when the optic disc is targeted by the scanning light sources, thus reducing the inaccuracy that results from head and eye movement and that also results from absorbance and reflectance of light by the surrounding fundus tissue layers.
Still yet another object of the present invention is to provide a method and apparatus for determining the arteriovenous oxygen difference in a given patient over a period of time and series of readings thus allowing the patient in question to provide his or her own base line reference.
It is yet another object of the present invention to provide an apparatus for non-invasively determining arteriovenous oxygen difference that is sufficiently mobile to allow examination of multiple patients in separate rooms or facilities.
Other objects and advantages over the prior art will become apparent to those skilled in the art upon reading the detailed description together with the drawings as described as follows.

Method and apparatus for monitoring the arteriovenous oxygen difference from the ocular fundus


The present invention provides materials and methods for the treatment of celiac disease. In addition, the present invention provides materials and methods of monitoring the treatment of a subject having celiac disease.

Celiac disease (CD) is a chronic autoimmune disease that is HLA-DQ2/DQ8 haplotype restricted. Gluten, the major protein fraction of wheat, and related proteins in rye and barley are the triggering agents of the disease. Ingested gluten or its' derivative fractions (gliadin and subunits) elicit a harmful T cell-mediated immune response after crossing the small bowel epithelial barrier, undergoing deamidation by tissue transglutaminase (tTG) and engaging class II MHC molecules. While the earliest events leading to CD involves innate immune responses, evidence in the literature seems to suggest that a dysfunctional cross talk between innate and adaptive immunity is also an important pathogenic element in the autoimmune process of the disease. Under physiological circumstances, the intestinal epithelium, with its intact intercellular tight junctions (tj), serves as a key barrier to the passage of macromolecules such as gluten. When the integrity of the tj system is compromised, as in CD, a paracellular leak ("leaky gut") and an inappropriate immune response to environmental antigens (i.e., gluten) may develop. While our knowledge about tj ultrastructure and intracellular signaling events have significantly progressed during the past decade, relatively little is known about their physiological regulation secondary to extracellular stimuli and their roles in diseases such as CD.
Zonulin is an endogenous paracrine signaling protein that appears to regulate epithelial and endothelial cell tight junction function in animals and humans (Fasano, A. Ann N Y Acad Sci. 915:pp214-22 (2000); Fasano, A. Gut. 49:pp159-62 (2001); Fasano, A. et al. Lancet 355:pp1518-19 (2000); and Wang, W. et al. J Cell Sci. 113:pp4435-40 (2000)), and whose prokaryotic analogues (eg., zonula occludens toxin, or "ZOT") possess immune stimulating effects when applied to mucosal surfaces in mammals (Marinaro, M. et al. Infect Immun 67:pp1287-91 (1999); and Marinaro, M. et al. Infect Immun 71:pp1897-902 (2003). In celiac intestinal tissues and in in vitro, ex vivo, and in vivo animal experiments, gluten/gliadin cause rapid zonulin release and zonulin-dependent increases in permeability (Drago, S. et al. Scan J Gastroenterol. 41:pp408-19 (2006); Fasano, A. et al. Gastroenterol. 112:pp839-46 (1997); Ventura, A. et al. Gastroenterol. 117:pp297-303 (1999); Schuppan, D. Gastroenterol. 119:pp234-42 (2000); Norris, J. M. et al. JAMA. 293:pp2343-51 (2005); Clemente, M. G. et al. Gut. 52:pp218-23 (2003); and National Institutes of Health. Consensus Development conference Final Statement dated Aug. 9, 2004. NIH consensus Development Conference on Celiac Disease. Bethesda, Md. Jun. 28-30, 2004) in normal and diseased states. Animal models likewise have demonstrated the association of gluten, increased paracellular permeability and other autoimmune diseases, including type 1 diabetes (T1D).
AT-1001 (Larazotide Acetate) is an orally administered octapeptide (Gly Gly Val Leu Val Gln Pro Gly (SEQ ID NO:15), that appears to inhibit gliadin-induced tj disassembly by blocking putative zonulin receptors on the luminal surface of the small intestine. Pretreatment with the peptide fails to inhibit gliadin induced zonulin release, while administration of zonulin analogues or gliadin in the presence of AT-1001 fail to significantly increase intestinal permeability, confirming that the effect of the molecule is specific to the zonulin receptor (Wang, W. et al. J Cell Sci. 113:pp 4435-40 (2000); and Drago, S. et al. Scan J. Gastroenterol. 41:pp 408-19 (2006)). Experiments with ex vivo human tissue and in mice demonstrate that AT-1001 blocks zonulin binding to its putative receptor, blocks the peak of F-actin increment induced by gliadin and inhibits gliadin induced reduction in intestinal Rt (resistance) (Wang, W. et al. J Cell Sci. 113:pp 4435-40 (2000); Drago, S. et al. Scan J. Gastroenterol. 41:pp 408-19 (2006); and Clemente, M. G. et al. Gut. 52:pp 218-23 (2003)). Furthermore, intranasal pre-administration of AT-1001 in mice prevented the ZOT-induced immune response to non-self antigen challenge (Marinaro, M. et al. Infect Immun. 71:pp 1897-902 (2003)).

Materials and methods for the treatment of celiac disease


Catalyzers for purification of exhaust gases are disclosed including a housing, an inlet for supplying the exhaust gases to the housing, a first catalyzer within the housing adjacent to the inlet and a second catalyzer within the housing downstream of the first catalyzer, the first catalyzer having a smaller cross-sectional area than the second catalyzer, and the inlet being angled with respect to the longitudinal axis of the first catalyzer.

Catalytic exhaust gas purifiers are often used in motor vehicles in order to purify the exhaust gases from the vehicle's engine. However, present catalytic converters (catalyzers) are not able to operate at full purification efficiency in connection with cold-starting of a vehicle. This problem can be overcome by arranging an additional, electrically-heatable start catalyzer in front of the ordinary catalyzer. By heating up the start catalyzer electrically, the warm-up time for the ordinary catalyzer can be shortened, which results in improved purification efficiency during cold starts. Such a catalyzer arrangement is shown in International Patent No. WO 80/10470.
A problem which occurs in connection with an electrically-heatable start catalyzer is that it requires a powerful electrical supply in order to be activated. This can, for example, be achieved by arranging an additional battery in the vehicle, which is however unnecessarily expensive and complicated. It is therefore desirable to have a catalyzer arrangement which is not dependent on an electrical supply, but which still produces a shortening of the main catalyzer's "ignition" time (the so-called "light-off" time), i.e. the time which elapses from starting the engine until the catalyzer is working at optimal purification efficiency. This should, in such a case, result in improved purification efficiency of the entire catalyzer arrangement.
In connection with conventional catalyzers, there is an additional problem in that the incoming exhaust gases impinge directly onto the catalyzer. This produces a turbulent flow immediately in front of the catalyzer, which leads to inefficient operation of the catalyzer as well as a comparatively high back-pressure, which is a disadvantage compounding the reduction in the efficiency of the catalyzer. One way of solving this problem is to direct the exhaust gases at an angle to the catalyzer, for instance in accordance with the disclosure in European Patent No. 420,462. This arrangement, however, presents a disadvantage in that it has relatively poor flow characteristics, since not only the inlet but also the outlet are angled with respect to the catalyzer.
A main object of the present invention is to solve the aforementioned problems and provide an improved arrangement for catalytic exhaust gas purification, in particular for shortening the light-off time of such an arrangement.
An additional object of the present invention is to achieve a correct measurement of the conversion efficiency of the aforementioned catalyzer arrangement, in order to provide information for a diagnosis of its operation. This allows an indication, e.g. in the form of a warning light, which warns the vehicle driver that the catalyzer is defective and has to be replaced.

Device for catalytic purification of exhaust gases


An ultrasonic locationing method and system for ultrasonic locationing of a mobile device within an environment includes a plurality of fixed ultrasonic emitters to transmit an instruction to listen for an enrollment tone to at least one communication device, and to sequentially emit an enrollment tone from each emitter at specific times to be received by those communication devices that implemented the instruction. A controller receives a response from each of those communication devices, the respective response including an identity of the communication device, a time the enrollment tone was received, and an indication of a hardware platform of the communication device. The controller can then assign a locationing mode to each communication device in accordance with its hardware platform. The communication device provides locationing information using its assigned locationing mode and locationing tones from active emitters.

An ultrasonic receiver can be used to determine its location with reference to one or more ultrasonic emitters, such as locating a mobile device having an ultrasonic receiver and being present within a retail, factory, warehouse, or other indoor environment, for example. The ultrasonic emitter(s) can transmit ultrasonic energy in a short burst which can be received by an ultrasonic transducer (audio microphone) in the ultrasonic receiver. The use of several ultrasonic emitters distributed within the environment can be used to provide a specific location of a particular device using techniques known in the art such as measuring time-of-flight or signal strength of the emitter signals and using triangulation, trilateration, and the like, as have been used in radio frequency locationing systems.
However, emitters may not always be in the line-of-sight of the mobile device, and typical emitter signals may not be strong enough to directly penetrate through obstacles very well, such that reflected signals reach the mobile device better than the direct signal. This leads to inaccurate locationing results. In addition, having many mobile devices trying to establish their position within the environment, and interacting with all the emitters in the environment cannot be done simultaneously due to the interference, which results in a poor position update rate.
One solution for locationing uses time-slicing, where each emitter can send its ultrasonic burst, and there is a wait time for any echoes to settle before the subsequent ultrasonic bursts are sent. This method solves the interference problem, but still results in a poor update rate, and does not resolve the non-line-of-sight inaccuracy issue.
Another solution for locationing could use more ultrasonic bandwidth, where a larger range of ultrasonic frequencies can be used. However, today's mobile devices have a very limited ability to hear ultrasonic frequencies, typically between 19-22 kHz. Therefore, the only way to expand usable bandwidth would be to replace the existing audio circuitry of the mobile device to operate on higher frequencies, which is cost prohibitive. Alternatively, the usable frequencies could be expanded down into the audio range, but this would become disruptive to the users.
Accordingly, there is a need for a technique to locate a mobile device in an indoor environment without modifying the phone hardware and while eliminating the aforementioned issues. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing background.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

Ultrasonic locationing using enrollment mode


The present invention provides a light emitting diode package including a light emitting diode chip, a lead frame having a chip area on which the light emitting diode chip is disposed, and a package body having a cavity and supporting the lead frame. The chip area is exposed through the cavity. The lead frame includes a first terminal group disposed at a first side of the chip area and a second terminal group disposed at a second side of the chip area. The first terminal group and the second terminal group each include a first terminal connected to the chip area and a second terminal separated from the chip area. The second terminal of the first terminal group is exposed through the cavity, and the second terminal of the second terminal group is buried in the package body.

1. Field
Exemplary embodiments of the present invention relate to a light emitting diode package and a light emitting module including the same.
2. Discussion of the Background
Generally, a light emitting diode package may include a light emitting diode chip, a lead frame, and a package body. The lead frame may include a plurality of terminals having different polarities. The package body may support the lead frame. The terminals may extend from the interior of the package body to the outside of the package body. The light emitting diode chip may be electrically connected to the terminals inside the package body. The package body may be formed of a plastic resin or ceramic material. The package body made of plastic material may have a cavity, which receives the light emitting diode chip while optically exposing the light emitting diode chip therethrough. Or, the package body may be at least partially transparent to allow light generated by the light emitting diode chip to be emitted to the outside therethrough.
A light emitting diode package having a plurality of terminals exposed to the outside of a package body may have some terminals exposed through one side of the package body and the other terminals exposed through the other side thereof. The terminals disposed at the one side of the package body and the terminals disposed at the other side of the package body may be connected to each other in a crossing region within the package body, on which the light emitting diode chip is mounted.
In one example of a conventional light emitting diode package, a separate terminal may be placed between two terminals disposed at one side of the package body, and another separate terminal may be placed between two terminals disposed at the other side of the package body.
In such a conventional light emitting diode package, the terminals may have a restricted width and may be arranged at restricted intervals within the restricted area of the package body, thereby causing failure upon electrical testing of the light emitting diode package.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.

Light emitting diode package and light emitting module comprising the same


Materials comprised of linked, repeat units of beta glucosamine, having a molecular weight in the range of 400 to 10,000 are highly effective in controlling fungus infestation in agricultural crops, both pre-harvest and post-harvest. The antifungal material is preferably combined with a mildly acidic solvent to produce a composition having a slightly acidic, or near neutral pH. When the antifungal material is combined with a chitosan matrix, a synergistic interaction occurs which greatly enhances the effect of the resultant composition. Also disclosed is a method for producing a chitin or chitosan based material which will dissolve in water having a neutral pH.

Historically, fungal infestations have caused significant losses to agricultural crops, and have been the cause of large scale famines and economic displacements. Fungal infections can cause pre-harvest damage to crops by killing them outright or weakening them so as to decrease yields and render the plants susceptible to other infections. Post-harvest, fungal infection also results in significant loss of agricultural products during storage, processing and handling.
Clearly, there is a significant need to control the fungal infection of agricultural products, and a number of chemical agents have been developed for this purpose, but to date no fully satisfactory agents have been found. Oftentimes, fungal control agents are highly toxic to crops and/or animals; consequently, restrictions are placed on their handling and use. Also, many presently available fungal control agents are of restricted utility; that is to say, a particular agent may be only effective against several types of fungus. As a result, a number of separate materials must often be employed in a particular agricultural setting. Also, a number of species of fungus have developed resistance to commonly employed fungicides.
Clearly, there is a need for a fungal control agent for plants which has broad activity against a variety of fungi, including those strains resistant to presently employed fungicides. The material should be of low toxicity to crops and to animals, stable in composition, easy to employ and preferably low in cost.
It is known that the cell walls of fungi are comprised of chitin, which is a natural, carbohydrate-based biopolymer. Chitin is an analog of cellulose in which the OH group at the C-2 position has been replaced by an acetamido group. Chitin is also found in a number of other natural sources, including the shells of arthropods. Chitin and chitosan are polymers having relatively high molecular weights, typically several hundred thousand or more; however, they can be hydrolyzed into lower molecular weight fractions, corresponding to shortened polymer chains. Previous research has suggested that chitin, or lower molecular weight fractions produced by its degradation, can in some instances, elicit antifungal responses in some plants; see for example M. G. Hahn et al. in Mechanisms of Plant Defense Responses; B. Fritig and M. Legrand, Kluwer Academic Publishers (Netherlands 1993, pages 99-116).
Chitosan is a semisynthetic derivative of chitin produced by the deacetylation of the nitrogen thereof so as to produce the ammonium salt. Chitosan has been shown to have some mild antifungal activity with regard to certain, particular fungal species, in some particular plants; see for example, L. A. 5 Hadwiger, J. M. Beckman; Plant Physiol. 66, 205-211 (1980); A. El Gharouth et al., Phytopathology, 84, 313-320 (1994); A. El Gharouth et al., Phytopathology, 82, 398-402 (1992); C. R. Allan, et al., Experimental Mycology 3:285-287 (1979); and P. Stossel et al., Phytopathology Z., 111:82-90 (1984). Specific hydrozylates of chitosan have also been described as having some antifungal activity. See for example, Kendra et al., Experimental Mycology 8:276-281 (1984). U.S. Pat. No. 5,374,627 describes the use of a composition of a high molecular weight chitosan hydrozylate (M.W. 10,000-50,000) and acetic acid for controlling fungus in certain crops. Japanese Patent Application 62-198604 describes the use of very low molecular weight chitosan hydrozylates (M.W..ltoreq.3,000) for the control of Alternaria alternata fungus in pears. It is further noted that this material is not effective, in pears, against other fungi such as botrytis.
U.S. patent application Ser. No. 08/453,651, of Ben-Shalom et al., discloses some specific oligosaccharide materials, including materials derived from chitin and chitosan, which have antifungal activity in plants. The disclosure of that application is incorporated herein by reference.
While some fungicidal activity of chitin and chitosan derived materials has been shown or suggested in the art, such utility is limited to particular pathogens and to particular plants. Furthermore, the prior art is uncertain as to which specific materials have beneficial effect. Certain references suggest that chitosan itself is to be employed as a fungal control agent, while other references suggest that high molecular weight fractions of chitosan are effective, and other references suggest that very low molecular weight fractions must be employed.
Another problem which the prior art has encountered in connection with chitin and chitosan based materials is that these materials have a very low solubility in water. Hence, solvent systems have to be employed to solubilize them, and this limits the utility of such materials. There is a need for a method whereby these materials can be rendered soluble in water having a neutral pH.
The present invention, as will be described in detail hereinbelow, is directed to fungal control agents derived from chitin and/or chitosan. This invention has identified a particular low molecular weight fraction of chitosan derived, material which is a broad spectrum antifungal agent, effective at very low doses. The present invention has also identified particular compositions containing this low molecular weight material and chitosan, in which the material and chitosan interact, synergistically, to provide an enhanced antifungal activity. The present invention has also identified particular low molecular weight oligomers of chitin which may be employed, either alone or with other materials, as agents for fungal control. It is to be understood that the terms "oligomers" and "low molecular weight material" are to a large extent synonymous in the context of this disclosure, since both refer to relatively short polymeric chains derived by reducing the molecular weight of chitin or chitosan. For the sake of clarity, the chitosan derived materials will generally be described as "low molecular weight" materials, while the chitin derived materials will be referred to as "oligomers." However, it is to be understood that either material could be considered an oligomer or a low molecular weight material. Collectively these substances will be deemed "materials of the present invention," or "antifungal materials."
The materials of the present invention are derived from natural sources, and have extremely low toxicity to animals and agricultural crops. In addition, the materials are stable, water soluble, easy to handle and low in cost. These and other advantages of the present invention will be readily apparent from the discussion, description and examples which follow.

Compositions and method for controlling fungal disease in plants

State of Israel, Ministry of Agriculture, Agricultural Research Organization, The Volcani Center


In a wireless communication network using point-to-point or point-to-multipoint communications, this disclosure teaches the use of combined packets for retransmission and corresponding soft value processing at a receiver, wherein combined packets are formed as the logical combination of two or more previously transmitted packets and allow the receiver to use a single combined packet to correct one or more failed packets. For example, with the combined packet retransmission and corresponding soft value receiver processing as taught herein, a given receiver can use a given combined packet to correct bit errors in all (failed) packets comprising the combined packet as long as the bit errors in a failed packet do not overlap (or align) with bit errors in the other failed packets comprising the combined packet.

1. Technical Field
The present invention generally relates to wireless communication networks, and particularly relates to packet retransmission processing and packet combining in such networks.
2. Background
Noisy communication channels, such as those present in wireless communication networks, inevitably cause communication errors. Channel coding schemes, wherein underlying information bits are interleaved and/or encoded for transmission, offer significant error protection and error detection capabilities, based on corresponding decoding processing at targeted receivers. Even with such schemes, however, decoding errors may arise at the receiver. Numerous retransmission techniques have been devised to deal with decoding failures, wherein receivers request packet retransmissions responsive to detecting packet decoding failures, e.g., detected CRC (cyclic redundancy check) failures.
In particular, one or more HARQ (hybrid automatic repeat request) retransmission schemes are integral to several current and developing wireless communication standards, including HSDPA (High Speed Downlink Packet Access) services and HSUPA (High Speed Uplink Packet Access) services in WCDMA (Wireless Code Division Multiple Access) networks. HARQ retransmission schemes commonly use either CC (Chase Combining) or IR (Incremental Redundancy) techniques for failed packet retransmission.
For example, in response to receiving a retransmission request for a given failed packet, a CC transmitter retransmits the failed packet. Correspondingly, the requesting receiver combines the repeated copy of the failed packet with its original copy, for improved decoding accuracy. In contrast, an IR transmitter retransmits a different set of parity bits related to a failed packet for which a retransmission request was received. The requesting receiver uses both the old and the new parity bits to detect/correct decoding errors in a subsequent decoding attempt for the failed packet. Because CC allows the receiver to combine the repeated packet with the originally received copy of that packet, its memory requirements are generally less than that of IR, where the receiver must retain the old and the new parity bits for re-decoding of the failed packet.
Despite its memory advantages for the receiver, CC-based retransmission schemes do not allow fine granularity with respect to changing the (en)coding rate used for retransmitted packets. For example, assume that a failed packet originally was transmitted using ½ rate encoding. Retransmission of that packet effectively reduces the coding rate for that packet to ¼. That reduction in coding rate represents transmission inefficiency to the extent that a less aggressive coding rate, ⅓, for example, would have sufficed.
Further, CC-based retransmission schemes can be particularly inefficient in select repeat contexts. For example, with selective repeat HARQ, consider the case where two packets A1 and A2 are broadcast to two receivers R1 and R2. It is possible, for example, that receiver R1 receives packet A1 incorrectly and receiver R2 receives packet A2 incorrectly. In that case, the transmitter has to resend the A1 packet so that receiver R1 can correctly decode the A1 packet, and has to resend the A2 packet so that the receiver R2 can correctly decode the A2 packet. Put simply, selective repeat retransmission schemes require a separate retransmission for each packet that is incorrectly received at any receiver within a given group of receivers.

Method and apparatus for combined packet retransmission and soft decoding of combined packets in a wireless communication network


A rate adaptive cardiac rhythm management device in which the pacing rate is adjusted in accordance with changes in the patient's minute ventilation. An adaptive four-pole elliptic digital filter, preferably implemented in software, functions to attenuate any signal components due to cardiac activity and motion from the minute ventilation signal over the range of breathing frequencies encountered in going from a sedentary state to active exercise. The pacemaker incorporates a microprocessor-based controller that is programmed to compute from peak-to-peak excursions of the sensed parameter the instantaneous tidal volume. Likewise, it computes, using a zero-crossing technique, the breathing interval. Knowing the breathing interval and the instantaneous tidal volume, it is possible to compute minute ventilation over a predetermined time interval and it is that factor that is employed in developing the ultimate control signal used to vary the stimulating rate between a lower rate limit and an upper rate limit.

I. Field of the Invention
This invention relates generally to implantable cardiac stimulating apparatus, and more particularly to a rate adaptive cardiac rhythm management device having a sensor for measuring trans-thoracic impedance variations and for deriving therefrom a control signal varying as a function of the patient's minute ventilation and which uses that control signal to adjust the rate at which it generates cardiac stimulating pulses to thereby accommodate the patient's physiologic demand.
II. Discussion of the Prior Art
The prior art is replete with patents which are designed to accommodate a patient's physiologic demand. In fact, there has been developed a whole class of implantable cardiac pacemakers which are referred to as being "rate adaptive", meaning that they do not merely generate cardiac stimulating pulses at a fixed, programmed rate irrespective of the patient's level of activity, but instead, operate to sense some parameter that correlates with metabolic need and then using the sensed signal, deriving a rate-controlling index for adjusting the pacing rate between a minimum or lower rate limit and a maximum or upper rate limit.
Parameters that have been sensed in the past include blood Ph, blood temperature, QT interval, blood oxygen saturation, respiratory rate, minute ventilation, etc. Specific control algorithms for developing the control signal based upon variations of the above parameters have each met with some problems. For example, where blood Ph is the parameter, sensor stability has been a problem. The Ph sensors used have been found to age and drift with time. Blood oxygen saturation can be measured using light emitters and sensors but they tend to complicate the lead system used to couple the pacemaker's pulse generator to the heart. Body temperature, on the other hand, while readily measured with a thermistor-type device, has proven to be a poor choice for use in a rate adaptive pacemaker because of the lag between the start of exercise and the detectable increase in blood temperature. Similarly, the use of ECG-based information, such as the pre-ejection period or the QT interval have not been entirely successful because of the difficulty in detecting the parameters in the presence of other myopotentials and motion artifacts typically involved.
Respiratory rate is also not a particularly suitable parameter on which the derivation of a rate control signal can be based. This is due to the fact that the correlation between heart rate and respiratory rate is not particularly strong or linear.
Another respiratory-related parameter that has been found to closely correlate with physical exercise and, therefore, metabolic demand is minute ventilation which may be defined as the volume of air inspired and expired during a predetermined time period. It has been found experimentally that minute ventilation (MV) tracks very well with metabolic need over a range of heart rates and, therefore, will provide a good index for a rate adaptive pacemaker, provided that the technique used to derive the MV signal is not contaminated by events other than respiratory activity.
It is known in the art that impedance plethysmography may be used to obtain an impedance vs. time analog signal that is modulated in accordance with the expansion and contraction of the thoracic cavity during inspiration and expiration. As is explained in the Pederson et al. Pat. No. 5,137,019, assigned to applicant's assignee, the impedance vs. time signal includes not only variations due to respiratory activity but due to cardiac activity and body motion as well. It is, therefore, desirable to isolate the information in the waveform relating to respiratory activity from that due to other causes. In the Hauck U.S. Pat. No. 5,074,303 entitled "Rate Adaptive Cardiac Pacer Incorporating Switched Capacitor Filter with Cut-Off Frequency Determined by Heart Rate", there is described an arrangement in which either systolic events or respiratory events can be selectively enhanced or attenuated by adjusting the analog filter parameters as a function of sensed heart rate. The present invention provides an alternative way for implementing the general concept disclosed in the Hauck Pat. No. 5,074,303 for effectively filtering out components in the Z vs. T waveform due to systolic function and motion artifacts over a range of heart rates and breathing rates which the patient would be expected to encounter in going from a sedentary state to a condition of vigorous exercise.

Rate adaptive cardiac rhythm management device control algorithm using trans-thoracic ventilation


A bubble generator includes an air intake device, an air guide device, an aeration disc and a rotating device. The air guide device is partially immersed in liquid and guides air flowed into the air guide device through the air intake device toward the liquid. The aeration disc produces negative pressure by being rotated in the liquid and moving the liquid whereby air guided by the air guide device produces air bubbles in the liquid. The aeration disc comprises one or more blades that spin to create a vacuum of air moving downward through the air intake device and air guide device and into the liquid, and an arcuate wall that comprises one or more slots.

The present invention relates to a bubble generator or aeration apparatus. More particularly, this invention relates to a bubble generator for aerating septic tank waste water that can produce substantial amount of micro scale air bubbles with a simple rotating mechanism that consumes minimal energy.
An aeration apparatus is used to produce gas bubbles in liquid. In a septic tank, an aeration apparatus is to supply oxygen in the waster water in the tank to promote decomposition of organic sludge by aerobic bacteria.
U.S. Pat. Nos. 5,194,144, 5,951,867 and 6,245,237 disclose an aeration apparatus for septic tanks. Air enters the upper end of a shaft and exits adjacent a propeller. The propeller rotates in the waste water. With high speed rotation of the propeller, air is moved from the atmosphere along the shaft and injected into the water as tiny air bubbles. The aeration apparatus agitates water with the propeller to produce air bubbles and move the produced air bubbles. Large energy was needed to rotate the propeller and the rotation of the propeller to agitate the water caused vibration of the parts rotating the propeller and interference of objects with the propeller and the driving parts.
U.S. Pat. Nos. 6,461,500 and 6,884,353, which are incorporated by reference in this application, disclose an aeration apparatus for septic tanks, which includes an impeller driven by a motor, and an air plate positioned between the impeller and the motor and having a series of concentrically positioned apertures. Air is injected into the waste water through the apertures of the air plate as the impeller is rotated by the motor. Air bubbles have smaller size, and the movement of water induced by the rotation of the impeller is much smaller compared to the apparatus of U.S. Pat. No. 6,245,237, so that the sludge in the tank is not agitated. The aeration apparatus of U.S. Pat. Nos. 6,461,500 and 6,884,353 has disadvantages that the apertures of the air plate are plugged easily; it is hard to balance the impeller and resulting vibration ruins the motor; and there is limit on pitch of the impeller for greater negative pressure.
The efficiency of aeration apparatus is closely related to the number and size of air bubbles that the apparatus produces. The smaller the size of bubbles is, the more efficient the aeration apparatus is. Smaller bubbles stay longer in the water, are easier to be dispersed by Brownian movement, and more efficient in transfer of oxygen since they have greater surface are for the same amount of air made into bubbles. There has long been a need to a bubble generator that can produce air bubbles having smaller size.


A method for treating drain in hydrogen production includes steps of gasifying in a gasifier (1), reforming in a reformer (2), gas-liquid separation in a gas-liquid separator (4), PSA gas separation in a PSA separator (5) and evaporation in a drain treatment unit (6). In the gasifying, a mixed material containing methanol is heated and gasified. In the reforming, reformed gas containing hydrogen is produced from the mixed material by reforming reaction of methanol. In the gas-liquid separation, a liquid component is separated from the reformed gas and discharged as drain. In the PSA gas separation, hydrogen-rich gas and offgas are extracted from the reformed gas by PSA separation using an adsorption tower. In the gasifying, the offgas is burned, and the mixed material is heated by using the combustion gas as heat source. In the evaporation, drain is evaporated using the combustion gas after heating the mixed material as heat source.

Hydrogen (high-purity hydrogen) is utilized in various industrial fields such as metal heat treatment, glass melting, semiconductor -manufacturing or optical fiber manufacturing. Hydrogen is also used as the fuel of a fuel cell.
An example of hydrogen production system for industrially producing hydrogen is disclosed in Patent Document 1 given below. The hydrogen production system disclosed in Patent Document 1 includes a gasifier, a reformer, a gas-liquid separator and a pressure swing adsorption gas separation apparatus and is designed to produce hydrogen using a hydrocarbon-based material as the main material. The gasifier serves to heat and gasify a mixed material containing a hydrocarbon-based material such as methanol or natural gas, water and oxygen before it is supplied to the reformer. In the gasifier, the mixed material flowing in the gasifier is heated to an appropriate temperature by utilizing high-temperature combustion gas produced by burning fuel as the heat source. In the reformer, the gasified mixed material is subjected to reforming reaction to obtain reformed gas (containing hydrogen). Specifically, in the reformer, both of steam reforming reaction which is endothermic reaction and partial oxidation reforming reaction which is exothermic reaction occur. For instance, in the steam reforming reaction, hydrogen as the main product and carbon dioxide as the sub product are produced from methanol and water. For instance, in the partial oxidation reforming reaction, hydrogen as the main product and carbon dioxide as the sub product are obtained from methanol and oxygen. In the gas-liquid separator, before the reformed gas produced by the reformer is supplied to the pressure swing adsorption gas separation apparatus which will be described later, the liquid component contained in the reformed gas is separated and removed from the gas and discharged as drain. In this hydrogen production system, the composition of the mixed material is so adjusted that the amount of heat absorbed by the steam reforming reaction and the amount of heat generated by the partial oxidation reforming reaction balance each other, whereby autothermal reforming reaction proceeds in which the reaction temperature in the reformer is maintained substantially constant.
Patent Document 1: WO2006/006479
The pressure swing adsorption gas separation apparatus serves to adsorb and remove unnecessary components, i.e., components other than hydrogen from the reformed gas to produce hydrogen-rich gas as product gas. The apparatus includes at least one adsorption tower loaded with an adsorbent for adsorbing preferentially the unnecessary components contained in the reformed gas. In the pressure swing adsorption gas separation apparatus, gas separation by the pressure swing adsorption gas separation method (PSA separation method) is performed. For instance, in the gas separation by the PSA separation method, a cycle including an adsorption step, a desorption step and a regeneration step is repetitively performed in an adsorption tower. In the adsorption step, reformed gas after passing through the gas-liquid separator is supplied into the adsorption tower where the unnecessary component contained in the reformed gas is adsorbed under high pressure, whereby hydrogen-rich gas is discharged from the adsorption tower. In the desorption step, the pressure in the adsorption tower is reduced for desorbing the unnecessary component from the adsorbent, and the gas (offgas) containing hydrogen remaining in the tower and the unnecessary component is discharged from the adsorption tower. In the regeneration step, the adsorption ability of the adsorbent for the unnecessary component is recovered by e.g. supplying cleaning gas into the adsorption tower.
In the adsorption step described above, the reformed gas from which the liquid components have been removed by passing through the gas-liquid separator is introduced Into the adsorption tower. Thus, the liquid components in the reformed gas are prevented from entering the adsorption tower. As a result, the deterioration of the adsorbent in the adsorption tower due to the contact with liquid components is prevented.
The offgas discharged from the adsorption tower is supplied to the gasifier as the fuel for combustion (fuel for gasifying the mixed material). In the gasifier, hydrogen gas contained in the offgas is burned to produce high-temperature combustion gas. The mixed material flowing within the gasifier is heated by the combustion gas utilized as a heat source to be gasified. The combustion gas after used for heating the mixed material in this way is discharged into the atmosphere.
In the hydrogen production system disclosed in Patent Document 1, the amount of offgas to be discharged from the PSA separation apparatus and supplied to the gasifier (supply per unit time) in the operation can be adjusted. This adjustment ensures that, during the normal operation after the lapse of a predetermined time from the start of the operation, the fuel required for heating and gasifying the mixed material at a desired temperature in the gasifier is provided only by the offgas supplied from the PSA separation apparatus. Moreover, in the hydrogen production system disclosed in Patent Document 1, the interior of the reformer is maintained at a desired reaction temperature by adjusting the ratio between the steam reforming reaction and the partial oxidation reforming reaction of the hydrocarbon-based material proceeding in the reformer. In this way, in the normal operation of the hydrogen production system disclosed in Patent Document 1, the heating and gasifying of the mixed material is performed only by the self-generating heat obtained in operating the system, and the interior of the reformer is maintained at a desired temperature. With such a thermally-independent hydrogen production system, hydrogen is produced efficiently by avoiding the inefficient technique of continuously heating the mixed material and the interior of the reformer by burning external fuel.
In recent years, restrictions on environmental pollutant and hazardous substances are strict, and further, restrictions on a method for treating industrial waste also tend to become strict. In the hydrogen production system disclosed in Patent Document 1, the drain removed by the gas-liquid separator is mainly composed of water contained in the mixed material. When the hydrocarbon-based material constituting the mixed material is methanol, the drain may contain unreacted methanol. In this case, to comply with the recent restrictions on hazardous substances, it is necessary to additionally provide a facility exclusively used for drain treatment or provide a facility for storing the drain and transfer the stored drain to a dealer as industrial waste.
However, to additionally provide a facility for drain treatment is not desirable, because the installation of the facility requires high cost. On the other hand, when the drain is to be disposed of by utilizing a drain storage facility, the cost for the maintenance and disposal of the drain is necessary in addition to the cost for installing the storage facility. Such cost for maintenance and disposal increases in accordance with an increase in the amount of drain, which increases in direct proportion to an increase in the amount of product gas (hydrogen-rich gas). These problems about the drain treatment are not peculiar to this hydrogen production system. For instance, other equipment or apparatuses for producing gas may involve the same problems.

Method for treatment of drain in hydrogen production and hydrogen production system


A light source that prevents broken pieces from dispersing to the outside without increasing the number of components while efficiently cooling a light-emitting tube is provided. The light source (10) has: a light-emitting tube (11) having a light-emitting portion (111) where light beam is emitted by electric discharge between electrodes and a sealing portion (112) provided on both sides of the light-emitting portion (111); a reflector (12) that reflects the light beam emitted by the light-emitting tube (11) forward after aligning in a predetermined direction; a cover (16) covering a light-irradiation opening of the reflector (12) and having an opening for irradiating the light beam reflected by the reflector (12), the cover having a heat-radiation fin (162) on the outside thereof and being made of a heat-conductive material to absorb the heat from the light-emitting tube (11), the absorbed heat being conducted to the heat-radiation fin (162); and a transparent member (14) that covers the opening of the cover (16).

1. Field of the Invention
The present invention relates to a light source having a light-emitting tube including a light-emitting portion that emits light by electric discharge between electrodes and sealing portions provided on both sides of the light-emitting portion and a reflector that irradiates the light beam emitted by the light-emitting tube after aligning in a predetermined direction, and a projector having the light source.
2. Description of Related Art
Projectors that modulate a light beam irradiated by a light source in accordance with image information to project an optical image in an enlarged manner have been conventionally used for presentation purpose at conferences etc. On the other hand, such projectors are also used for home-theater purpose in response to increasing demand for watching movies etc. on a wide screen at home.
Light sources used for such projectors have a lamp housing accommodating a reflector and a discharge light-emitting tube such as a metal halide lamp and a high-pressure mercury lamp so that the light source can be attached to and detached from the projectors together with the lamp housing for the convenience of exchanging the light-emitting tube when the light-emitting tube fails to light or is exploded.
Since the light source is exchanged by users of the projectors, the light source is constructed in an explosion-proof manner where light-emitting opening of a reflector in which a light-emitting tube is disposed is covered with a transparent plate such as glass so that broken pieces of exploded light-emitting tube are not scattered around when the light source is detached from the projector.
On the other hand, since the light-emitting tube generates heat together with light, cooling air is preferably blown to cool the light-emitting tube in order to lengthen the life of the light-emitting tube.
A light source having both of the explosion-proof construction and the cooling mechanism has been known, where a pair of cooling-air-introducing openings are formed on the light-emitting opening of a reflector symmetrically around the light-emitting tube (see Japanese Patent Laid-Open Publication No. 2002-107823 [0047], [0048], FIG. 7).
The light source has a lid on the lamp housing for opening/closing the opening of the reflector. The lid is opened when the light source is attached to the projector to allow the cooling air to be introduced. On the other hand, when the light-emitting tube is exploded and the light source is detached from the projector for exchanging the light source, the lid shuts the opening of the reflector to prevent the broken pieces from scattering to the outside.
However, according to the light source disclosed in the Japanese Patent Laid-Open Publication No. 2002-107823, since the lid has to be provided on the lamp housing and a biasing member such as a helical spring is necessary for opening/closing the lid in attaching/detaching the light source to/from the projector, so that the number of components of the light source is increased to deteriorate the efficiency of the assembly work and production cost is increased in accordance with the increase in the number of the components. Further, when the light source is attached to the projector, since the lid is opened, some broken pieces may be scattered inside the projector.