A method of detecting an object located within a dynamic scattering media, includes i) directing a continuous coherent light wave of predetermined wavelength into the media; ii) detecting dynamically scattered light emerging from the media; iii) correlating the detected light photons in the time or frequency domain; iv) determining the presence of an object from analysis of differences between the correlation and a correlation which would arise from photons scattered by the media only; and v) determining the approximate position of the object within the media from the analysis of the correlation and knowledge of the mean transport path of the light wave of predetermined wavelength within the media.

1. Field of the Invention
The present invention relates to a method and apparatus for detecting and/or imaging an object.
2. Related Art
Image through turbid media is often carried out using Time of Flight measurements. Various methods of time of flight measurement are known. The majority of these methods measure the time taken by pulses of light to travel a return path. Since the velocity of light is both constant and known for most materials, measurements of time of flight can be readily converted into images of the medium through which the light has passed.
Time of Flight imaging is particularly useful when imaging over large distances or in semi-turbid media. However, when dealing with short distances image resolution decreases rapidly, since the speed of light is so great that, for example, a spatial resolution of 1 m will require a detector with a temporal resolution of 5 ns. The shortest measurable distance and the image resolution obtainable using Time of Flight imaging is thus limited by the response time of the detectors used. A further disadvantage or Time of Flight imaging is that the reset time of the detectors used is considerably longer than the jitter time, so that the detectors are only capable of detection for a very short period of their total operating time. An alternative method of imagine through turbid media is it use acoustic waves (eg. ultrasound imaging). However, acoustic imagine suffers from lack of spatial resolution due to the large divergence of acoustic waves.
A further known method of imaging comprises forming an image of an object from interference of two beams of coherent light, one of which has been scattered from a target (ie. holographic imaging). Holograms have been used to analyse non-visible parameters of a target, for example, vibration of an engine block. Holographic imaging suffers from several disadvantages Firstly, holograms require two investigative beams that must interfere and be coherent over the distance to the target. Secondly, holograms are not suited to imaging through opaque media. An image cannot therefore be produced at a distance greater than a single photon transport path of the light used to obtain the hologram. Thirdly, holograms arc unsuited for measurement through media that exhibit dynamic scattering, and the scattering will reduce the quality of images obtained.
Several known imaging techniques exist where an investigative wave is perturbed as it passes, scatters, reflects or is absorbed by a target. These techniques require that the form of energy used for the investigative wave, and its frequency, must be chosen to interact with the target and cannot thus be fully optimised for detection (i.e. low absorption an/or high spatial resolution and/or high signal to noise).
It is an object of the present invention to overcome or substantially mitigate the above disadvantages.
According to a first aspect of the present invention there is provided a method of detecting an object located within a dynamic scattering media, the method composing:
i) directing a continuous coherent light wave of predetermined wavelength into the media;
ii) detecting dynamically scattered light emerging from the media;
iii) correlating the detected light photons in the time or frequency domain;
iv) determining the presence of an object from analysis of differences between said correlation and the correlation which would arise from photons scattered by the media only; and
v) determining the approximate position of the object within the media from said analysis of the correlation and knowledge of the mean transport path of the light wave of predetermined wavelength within the media.
The term xe2x80x9clight wavexe2x80x9d is not limited to visible light but is to be interpreted as encompassing electromagnetic radiation of any suitable wavelength.
The media may be a turbid media of relatively high density and the object may be more or less dense and more or less viscous than the media. The object may be an object which absorbs and/or reflects the incident light waves.
The invention (from hereon referred to as Diffuse Wave Imaging) incorporates aspects of the known technique of Diffusing Wave Spectroscopy (DWS). DWS is used for sub-micron particle sizing and bulk rheology measurements in dense suspensions or emuisions. DWS is not applicable to the imaging of single objects within turbid media. Furthermore, DWS is not used to identify individual particles. The suppression of photons close to the axis of the auto-correlation traces is treated as a limitation of DWS. The inventors have realised that this suppression of photons which have undergone multiple scattering events can be used to determine the presence of an object, and by taking many measurements, to form an image.
The invention allows images to be obtained using photons which have travelled optical distances greater than 2 photon transport paths. This is opposite to conventional imaging of dense media, which generally removes or filters out light which has been scattered more than once. Since the invention does not require photons which have undergone ballistic and low order scattering, it is suitable for imaging very dense suspensions where ballistic scattering is limited.
The steps (i) to (v) may be iterated either sequentially or simultaneously using coherent light waves of different predetermined frequencies having different mean transport paths within the dynamic scattering media, to thereby obtain further information as to the approximate position of the detected object from the analysis of the respective correlations and knowledge of the respective mean transport paths. For instance, light of three different wavelengths may be used.
The or each iteration of steps (i) to (v) may be repeated, either sequentially or simultaneously, for additional locations within the media, the results then being combined to construct an image of the object within the media. Where only one wavelength of light is used the image will be two dimensional. However, using two or more different wavelengths as mentioned above (which effectively probe into different depths of the media and/or object, enables the construction of a, three dimensional image.
The light emerging from the media may be detected at one or more predetermined scattering angles, preferably a scattering angle of 180xc2x0 and/or 0xc2x0.
The media may be modulated to induce, or enhance, dynamic motion within the media to provide or enhance the required dynamic scattering. Similarly, when the object is an object which is at least partially reflective of the or each light wave, the object may be modulated to enhance phase chances in light reflected therefrom.
The method may included the step of selecting for detection light which has a predetermined component of polarisation. The selection may be accomplished using polarising filters or fibre optic cables which preserve only one particular component of polarisation.
The or each light wave may be passed through a window prior to entering the media, the window being arranged to reflect light which is detected together with light emerging from the media, thereby producing a heterodyne signal. The window may be adjustably displaced relative to the origin of said light wave to allow control of the intensity of the reflected light which is detected. The window may be arranged to cause the reflected light to undergo multiple reflections before being detected, thereby enabling the path length travelled by the reflected light to be controlled.
The method may be performed on a human or animal body to detect the presence and approximate positions, or construct an image of a pathological entity within the body.
According to a second aspect of the present invention there is provided a method of detecting the presence of a pathological entity within the human or animal body, the method comprising:
i) directing a continuous coherent light wave of a first predetermined wavelength into the body;
ii) detecting dynamically scattered light emerging from the body;
iii) correlating the detected light photons in the time or frequency domain; and
iv) determining the presence of a pathological entity from analysis of differences between correlation and the correlation arising from photons scattered by the media surrounding the entity only.
According to a third aspect of the present invention there is provided apparatus for detecting an object located within a dynamic scattering media, the apparatus comprising means for directing a continuous coherent light wave of a predetermined wavelength into the media, means for detecting dynamically scattered light emerging from the media, means for correlating the detected light photons in the time or frequency domain, whereby the presence of an object can be determined from analysis of differences between said correlation and the correlation which would arise from photons scattered by the media only, the approximate position of the object within the media can be determined from said analysis of the correlation and knowledge of the mean transport path of the light wave of predetermined wavelength within the media.
A plurality of detectors may be arranged in an array to provide a series of measurements simultaneously. The array of detectors may be coupled to 3 CCD camera.
Preferably the or each detector is either located adjacent the emitter or is displaced from the emitter and is located on the axis of emission of the emitter
The coherent light producing means produces both visible light and infrared light.
Polarising filters may be located in front of the detection means to select either light with a polarisation perpendicular to the light emitted from the emitter, or to select light with the same polarisation as the light emitted from the emitter.
An object located within a medium may be caused to modulate to increase the contrast of the phase of scattered light, and thereby improve the resolution of the image.
The invention may be used in combination with Time of Flight apparatus to provide imaging over both short and long distances.
Where heterodyne detection is to be used, the coupling means may be provided with a window which will reflect a fraction of the light towards the detection means, thereby providing a heterodyne signal.
The window may be adjustably displaced from the coupling means to allow control of the intensity of reflected light incident at the detection means.
The window may be arranged to cause the reflected light to undergo multiple reflections before being incident at the detection means, thereby allowing the path length traveled by the reflected light to be controlled.
The coupling means and detection means may comprised polarisation preserving optical fibres. The fibres may be mounted so as to be rotatable through 90 degrees, thereby allowing modification of the effective numerical aperture of the fibres.
Preferably the means for producing coherent light comprises a laser.
Preferably four lasers operable at a different wavelength are used concurrently.
Preferably, two of the lasers are arranged to produce orthogonally polarised light, and a polarising beamsplitter cube is provided to couple the light into a polarisation preserving optical fibre.
The coupling means and detection means may comprise optical fibres with terminations located in a probe comprising a cylindrical head.
According to a fourth aspect of the present invention there is provided apparatus for detecting the presence of a pathological entity within the human or animal body, the apparatus comprising means for directing a continuous coherent light wave of a first predetermined wavelength into the body, means for detecting dynamically scattered light emerging form the body, and means for correlating the detected light photons in the time or frequency domain, whereby determining the presence of a pathological entity may be determined from analysis of differences between said correlation and the correlation arising from photons scattered by the media surrounding the entity only.
According to a fifth aspect of the present invention there is provided a method of detecting the presence of an object within a media, the method comprising
i) inducing vibration in the object at a predetermined frequency which does not propagate efficiently within the media;
ii) generating a continuous coherent light wave;
iii) modulating the generated light wave at a second predetermined frequency;
iv) directing the modulated coherent light wave into the media;
v) detecting scattered light emerging from the media;
vi) analysing the detected scattered light for the existence of a beat signal corresponding to the beat frequency between the first and second predetermined frequencies thereby indicating the presence of the object.
The frequency of the induced vibration is selected to correspond To the resonant frequency of the object, or regions within the object to be detected. Such regions may for instance be regions of stress, such as cracks in the object.
The vibrating frequency may be varied until the object, or parts of the object to be detected, resonates, and wherein the size of the resonating object, or region of the object, is determined as a function of the resonating frequency.
An image of the object, or parts of regions of the object to be detected, may be constructed by detecting light scattered from different parts of the object.
The method may be performed on a human or animal body to detect the presence, or construct an image, of a pathological entity within the body.
The invention also provides apparatus for detecting the presence of an object within a media, the apparatus comprising:
i) means for inducing vibration in the object at a predetermined frequency which does not propagate efficiently within the media;
ii) means for generating a continuous coherent light wave;
iii) modulating the generated light wave at a second predetermined frequency;
iv) means for directing thy modulated coherent light wave into the media;
v) means for,detecting scattered light emerging from the media;
vi) means for analysing the detected scattered light for the existence of a beat signal corresponding to the beat frequency between the first and second predetermined frequencies thereby indicating the presence of the object.
The method and apparatus according to the fifth aspect of the invention may be used to investigate properties that cannot be imaged directly such as scaling in an oil pipe or cracks in a metal structure.
The modulation frequency may be used to perform a secondary function on the object. For example, resonance may be used to cause descaling of a pipe whilst an image (by means of measurement of the change in the magnitude of resonance at a single frequency or preferably the change in the resonant frequency) is used to monitor the descaling operation in real time. Similarly, where the methods is used on a human or animal body, the same method may be used to remove or destroy pathological entities such as tumours (wherein the resonance may heat and kill the target), gall stone (wherein the resonance will physically break down the target), kidney stones, and other growths, foreign bodies and abnormalities. A similar method may be used to remove blockages etc. in non-medical applications, such as to remove blockages from target objects such as underwater pipe lines or cables.
Resonance may also be used to modify the target object means of chemical release or activation.
The invention may utilise a naturally occurring source as the source of the investigative wave.
The present invention may be combined with existing detection or imaging systems, such as time of flight systems, CAT, electron resonance etc.
Other possible features of the invention will become apparent from the description below.

Method and apparatus for detecting an object within a dynamic scattering media


Method and related apparatus for image processing. When projecting a polygonal object in three-dimensional space onto a two-dimensional screen according to a viewing range, faces of the object which intersect boundaries of the viewing range are clipped to form clipped planes. Vertices of all of the clipped planes of the object are recorded in one vertex list according to a triangle-list primitive, so as to increase efficiency of the image processing.

1. Field of the Invention
The present invention provides a method and related apparatus for image processing, and in particular, a method and related apparatus for clipping a three-dimensional object according to a viewing range and recording vertices after clipping in a better primitive, and hence improving image processing performance.
2. Description of the Prior Art
Presenting various documents, information, results and data with graphics makes browsing, viewing, observing and arranging easy for users. This has also become one of the most important functions of a modern computer system. Virtual reality graphical presentation allows the users to view a three-dimensional (3D) object, which plays an important role in fields of medical images, Computer-Aided Design/Computer-Aided Manufacture (CAD/CAM), virtual reality (such as flight simulation), multimedia games, etc. Thus, virtual reality 3D graphical presentation technologies are one research emphasis of a modern information industry.
In techniques of presenting 3D graphics, 3D objects and scenes in a virtual 3D space are processed to have the objects and scenes projected and displayed on a two-dimensional (2D) screen. The 2D screen can be equivalently seen as a photo of the 3D space which is taken by a virtual camera. Viewing graphics displayed on the 2D screen is just like observing the objects and scenes through a 2D image (i.e. a photograph) taken by a virtual camera. And in this way, the prior art can realize graphical representations of the virtual reality.
In modern techniques of presenting 3D space, a 3D object in a virtual 3D space can be formed with many faces, so the 3D object is also called a polygonal object. In fact, due to a special geometric characteristic of a triangle, i.e. that three vertices are always coplanar, faces of a 3D object are divided into one or more triangular planes with a triangle as a primitive. Finally the 3D object takes the triangular plane as a primary structural unit; the 3D object is formed by assembling all of the triangular planes. Since a location of a triangular plane can be defined by coordinates of its three vertices, a location and volume of an object occupying a 3D space can be represented with a vertex list that compiles the coordinates of each triangular plane of an object.
For people who are familiar with the art, when forming planes of any shape or 3D objects with combinations of triangular planes, since different triangular planes typically align together to form particular primitives, when recording the vertices of the triangular planes from the combinations of the triangular planes in the vertex list, the vertices can be recorded in different primitives according to different modes and sequences in a same list. Please refer to FIG. 1. FIG. 1 represents how to record vertices of a polygon in a vertex list with different primitives. FIG. 1 shows a pentagon as an example. The pentagon has four vertices A1 to A5, which can be divided into three triangular planes as shown. When describing the pentagon with vertices of the triangular planes, the three triangular planes can be seen as three independent triangles. Therefore, according to a triangle-list primitive, coordinates of the vertices are recorded in a vertex list as {A1, A2, A3, A1, A3, A4, A1, A4, A5}, which is simply recording the vertices of each triangle sequentially. On the other hand, the three triangular planes can be seen as a triangle-fan primitive since the three triangular planes share a vertex. The triangle-fan has a vertex A1 as its center, and therefore a sequence {A1, A2, A3, A4, A5} is recorded in a vertex list according to the triangle-fan primitive. The triangle-fan primitive takes the vertex A1 as the center of the fan and records each vertex consecutively. Other vertex list primitives include a triangle-stripe, etc.
It can be seen from the above discussion of primitives that given one triangle plane configuration, the vertex list can have different contents if the coordinates of the vertices of the triangles are recorded in the vertex list according to the different primitives. Thus, the vertex list must have a corresponding primitive. When reading the vertex list, the vertex list must be read with respect to a sequence defined by a corresponding primitive, so that a correct description of a polygon or an object can be obtained from the vertex list.
By describing objects and scenes in a virtual 3D space with vertex lists, and appropriately processing each vertex list, a position of each vertex as it is projected on a 2D screen can be calculated. Effectively projecting the 3D space on the 2D screen is equivalent to forming an image on the 2D screen by a virtual camera.
However, like a real camera, the virtual camera also has a specific viewing range. For example, an object placed right in front of the camera is projected in the center of a photo (a 2D screen), while an object placed at the left/right side of the camera may not be captured by the camera and hence may not be presented in the photo. An object that extends from the front of the camera to the left/right side of the camera is only presented partially in the photo; the rest of the object is outside the viewing range and hence not shown in the photo.
Similarly, in 3D graphics presentation techniques, when projecting a 3D object onto a 2D screen, it is necessary to calculate whether the object lies in a range of a virtual camera. If an object lies completely outside the viewing range, that means the object would not be projected in a photo (2D screen), and that further means there is no need to process a redundant calculation for the object outside the viewing range during image processing. Correspondingly, if an object lies partially inside the viewing range and partially outside the viewing range, a clipping procedure is executed on the object to keep a portion of the object that is captured inside the viewing range and only project the portion kept onto the 2D screen.
Clipping an object in a 3D space according to a viewing range involves clipping triangular planes since the object is constructed with triangular planes. If the object extends across the viewing range, then one or more triangular planes will intersect with boundaries of the viewing range, meaning these triangular planes comprise some vertices inside the viewing range and some vertices outside the viewing range. For instance, if a triangular plane comprises a vertex outside of the viewing range, after clipping, the triangular plane is clipped to form a clipped plane that might be a quadrangle or a pentagon. By replacing triangular planes of the object that extends across the viewing range with clipped planes, and discarding triangular planes that lie completely outside the viewing range, triangular planes that are originally inside the viewing range are kept, and hence a clipping process of the object is completed.
As discussed above, to project an object in a 3D space onto a 2D screen, the object should be constructed with triangular planes. So when processing clipping as described above, clipped planes formed after clipping still need to be divided into triangular planes, and further, vertices of the triangular planes need to be recorded. For example, if a triangular plane is clipped to form a quadrangle clipped plane, the clipped plane will be divided further into two triangular planes. Therefore, the clipped plane is represented by the two triangular planes.
In the image processing techniques of the prior art, when recording the vertices of the triangular planes of each clipped plane, the vertices of each clipped plane are recorded in a vertex list as a triangle-fan primitive. In other words, if an object comprises N triangular planes crossing in and out of the viewing range, after clipping the N triangular planes into N clipped planes, the prior art records the vertices of each clipped plane corresponding to N triangle-fan primitives in vertex lists.
After completing the clipping procedure, the 3D graphics presentation technique can perform pixel-level processing to calculate an image that will be presented on the 2D screen by each triangular plane of the object. Since the 2D screen may present images with pixels as units, when performing the pixel-level processing, numbers of pixels occupied by each triangular plane can be calculated, along with a color, brightness, and texture thereof.
During practical pixel-level processing, the process receives vertex lists corresponding to each object, reads/connects corresponding triangular planes according to a primitive corresponding to each vertex list, and perform relative calculations for the 2D screen according to positions of the triangular planes. However, because the prior art uses a plurality of vertex lists to describe a plurality of clipped planes, processing efficiency is affected during pixel-level processing.
As mentioned above, when reading a vertex list, a reading order must be set according to a primitive corresponding to the vertex list first, and so as to an original plane can be correctly formed by connecting vertices. However, the process of setting the reading order consumes a large amount of system resources. In particular, because the prior art generates a plurality of vertex lists for a plurality of clipped planes when clipping an object, the result is that the setting and reading processes are repeated many times for each vertex list, which increases the system resources consumed and affects processing efficiency.
For example, a modern computer system usually uses graphics processing hardware to realize pixel-level processing, wherein pipeline processing hardware is used to read vertex lists. Since the prior art records vertices of different clipped planes in many vertex lists when processing the vertices of the clipped planes, the pipeline processing hardware must repeatedly flush the pipeline when reading each vertex list before it can perform setting of the reading order, which brings down the overall graphics processing performance.


Self-expandable bifurcation stent and systems for delivery and implantation of the self-expandable bifurcation stent, comprising a self-expandable bifurcation stent made of a material possessing shape memory, capable of shaping a mesh with cylindrical surface and marked by radioactive labels, and the delivery system for its implantation, comprising a polymeric tubular catheter with a cap at the distal end, a guiding wire and a pushing wire, where the tubular catheter is executed double-barreled, one lumen accommodating the guiding wire, and the second lumen accommodating the pushing wire with a cap at its distal end, which cap is executed in the shape of a polymeric elastic cap put over the tubular catheter accommodating, between the polymeric elastic cap and the tubular catheter, the stent in the first position with the reduced diameter, the cap is executed with the capability of distal 5 moving along the guiding wire and along the tubular catheter accommodating the stent, by means of the pushing wire, and with capability of unrolling the stent at the proximal end into the second position with greater diameter, and the capability of backwards proximal moving thus returning the stent to its first position in the tubular catheter.

The invention relates to medical devices, namely to the devices applied in endovascular surgery and interventional cardiology for recovery of narrowed bifurcated sections of a vessel lumen, in particular, in a side branch of the coronary arteries or in the carotid arteries bifurcation.
Fixing a stent in arteries in a bifurcated zone, especially in coronary arteries, constitutes one of the main problems of endovascular surgery and of interventional cardiology in particular. At the present moment, stent techniques, where a stent is implanted into the basic artery are rather common. An additional wire is introduced in a lateral branch through a mesh of the stent and the final angiographic result of the operation is achieved after the balloon angioplasty of the bifurcated zone by two "kissing" balloons. Stenting of bifurcated lesions of arteries is also performed by two stents simultaneously (using techniques: such as cullotte, crush, V-stenting, T-stenting), which represents a high risk of a damage of the arterial wall, a high risk of restenosis and intra-operational technical difficulties. Full optimization of the diameter of an artery in a bifurcated zone by using conventional stents is a difficult problem. There are some designs of special bifurcation stents (for example, the Multi-Link Frontier Stent from Guidant) where the technical result is achieved due to two balloons and two wires on which the stents are clipped and which are positioned both in the basic artery and in a lateral branch. Another type of bifurcation stents has a special mesh structure which has the aperture for a lateral branch (SLK-View™ stent, Advanced Stent Technologies), that allows optimizing implantation of the second stent in a lateral branch. In clinical practice, a Nitinol bifurcation stent by AXXESS Plus, Devax, Inc. is commonly used. The stent is designed in the shape of a frustum, thus, the basic advantage of this stent is the lower probability of shifting plaque masses in a lateral branch during stenting the basic artery. At the same time, all bifurcation stents used today in the clinical practice, have design which, to certain extent, ensures stenting the basic artery and reinforcement of an ostium of a lateral branch, but they do not provide full covering along a lateral branch. These stents have, as a rule, a rather complicated design and the restricted spectrum of application.
From the Russian Patent RU2192810, a set of tools for transluminal insertion of a tubular stent, including self-expandable tubular stent which serves as a transplant, and a device for introduction of the stent, are known. The tool set does not solve the problem of high precision installation of the stent in an ostium of a lateral arterial branch.
An eccentric stent for implantation in a lateral arterial branch is known; it is expanded by means of a balloon catheter (see laid open U.S. Patent Publication No. 2004/0186560). The design of the above stent is adapted for implantation in an ostium segment of a lateral branch of a coronary artery. However, the system of radioactive labels used in this design, does not provide for accurate positioning of the truncated part of the stent in the ostium of the arterial segment that can essentially reduce the safety standard of endovascular operations.
Another solution is presented in Russian patent RU2121317. In this solution the self-recovering stent with delivery system for its implantation in the blood vessel, composing an implantation system, including self-expandable bifurcation stent marked by radioactive labels and made of a wire shaping a cylindrical mesh which material has the shape memory, and the delivery system for implantation of the self-expandable bifurcation stent, containing a polymeric tubular catheter with a polymeric cap at the distal end, a guiding wire and a pushing wire, is described. Though this system has the orientation agents in the form of the radioactive labels located on the stent, the extremely close disposition of labels seriously hampers the accurate orientation by the clipped labels.

Self-expandable stent delivery system for bifurcated lesions


The present technique provides a system and method for automatically releasing a power connection between an aircraft and a ground power unit. The power connection may have a release mechanism, such as a straight-pull coupling, which disconnects in response to movement of the aircraft or the ground power unit. The release mechanism also may disconnect in response to a critical tension within a power cable of the power connection. The power connection also may have a rotatable mount for the release mechanism, such that the power cable is alignable with tension in the power cable. The present technique also may have a variety of sensors to trigger a power shutdown and automatic release of the power connection.

The present technique relates generally to aviation systems, and more particularly, to ground power units. In particular, the present technique provides a system and method for providing power to an aircraft on the ground from a ground power unit using an automatically releasable connector.
A ground power unit (GPU) is often used to supply power to an aircraft on the ground, such as during passenger loading/unloading, servicing, or other ground support operations. The GPU generally comprises an engine driven generator having an integral power cord, which is connectable tightly within a power receptacle at an underside of the aircraft. In instances where the aircraft is moved without disconnecting the GPU, damage may result to the GPU and the aircraft.
Accordingly, a technique is needed for releasably coupling and automatically releasing a power connection between the ground power unit and the aircraft in response to movement of the ground power unit or the aircraft.

Aviation ground power unit connection system and method incorporating same


Unsymmetrical cyanine dyes that incorporate an aza-benzazolium ring moiety are described, including cyanine dyes substituted by a cationic side chain, monomeric and dimeric cyanine dyes, chemically reactive cyanine dyes, and conjugates of cyanine dyes. The subject dyes are virtually non-fluorescent when diluted in aqueous solution, but exhibit bright fluorescence when associated with nucleic acid polymers such as DNA or RNA, or when associated with detergent-complexed proteins. A variety of applications are described for detection and quantitation of nucleic acids and detergent-complexed proteins in a variety of samples, including solutions, electrophoretic gels, cells, and microorganisms.

As researchers in the fields of molecular and cell biology increasingly utilize fluorescent probes as research tools, the ability to select the wavelength of fluorescence is becoming critical. As increasing numbers of multiple-color applications are developed, the ability to produce novel fluorescent probes with detectably distinct fluorescent signals is becoming ever more important.
Unsymmetrical cyanine dyes have previously been used as fluorescent stains for nucleic acids, see for example U.S. Pat. No. 4,883,867 to Lee, et al. (1989) and U.S. Pat. No. 4,937,198 to Lee, et al. (1990). The general spectral properties of the previously described cyanine dyes could be selected somewhat by changing the number of methine groups in the dye, and whether the dye incorporated a pyridinium or quinolinium ring system (see, for example, U.S. Pat. No. 5,321,130 to Yue et al. (1994); U.S. Pat. No. 5,410,030 to Yue et al. (1995); U.S. Pat. No. 5,436,134 to Haugland et al. (1995); U.S. Pat. No. 5,582,977 to Yue et al. (1996); U.S. Pat. No. 5,658,751 to Yue et al. (1997); and U.S. Pat. No. 5,863,753 to Haugland et al. (1999). In particular, monomethine dyes that incorporate pyridinium ring systems typically exhibit blue to blue-green fluorescence emission, while those that incorporate quinolinium ring systems exhibit green to yellow-green fluorescence emission. Trimethine dyes are substantially shifted toward red wavelengths, and pentamethine dyes are typically shifted even further, and may exhibit infrared fluorescence emission.
While the spectral properties of cyanine dyes can be finely adjusted by selection of appropriate dye substituents, there were nevertheless regions of the visible spectrum where suitable fluorescent cyanine dyes that were useful as nucleic acid stains either did not exist, or did not possess particularly favorable fluorescence properties.
The dyes of the invention incorporate additional nitrogen atoms in the aromatic benzazolium portion of the dye. The dyes of the invention exhibit a bathochromic spectral shift (a shift to longer wavelength) of approximately 30 to 50 nm relative to otherwise structurally similar cyanine dyes known in the art. This bathochromic spectral shift yields dyes that are particularly useful for excitation in the wavelength ranges between 500 nm and 600 nm and at >630 nm. Of particular importance are the dyes of the invention that exhibit absorbance maxima between 530 nm and 550 nm, as they match the principal emission lines of the mercury arc lamp (546 nm), frequency-doubled Nd-Yag laser (532 nm), and HeNe laser (543 nm).
Styryl dyes that complex with lipid-complexed poly(amino acids) have been described previously (U.S. Pat. No. 5,616,502 to Haugland et al., 1997). Cyanine dyes that incorporate a 3,4-diazaindene ring system have been described previously for use as optical sensitizers in photographic materials (British patent No. 870,753 to Ficken et al., (1961)), but their use in association with either nucleic acids or lipid-complexed proteins as fluorescent stains has not previously been described.


An apparatus for driving a display panel can execute quality image display. To allow discharge cells operating as pixels of the display panel to repeatedly perform sustain discharge, a fall period of a last sustain pulse of sustain pulses repeatedly applied to row electrodes includes a first voltage drop period in which a voltage value gently drops, a voltage constant period which follows the first voltage drop period and in which the voltage value remains constant for a predetermined period, and a second voltage drop period which follows the voltage constant period and in which the voltage value drops more gently than in the first voltage drop period.

1. Field of the Invention
This invention relates to a driving apparatus of a display panel having capacitive discharge cells.
2. Description of the Related Art
A plasma display apparatus having an AC discharge type plasma display panel mounted thereto as a thin display device is known.
The AC discharge type plasma display panel (hereinafter called "PDP") includes a plurality of column electrodes and a plurality of row electrode pairs so arranged as to respectively intersect the column electrodes while interposing discharge spaces having a discharge gas sealed therein among them. A discharge cell emitting red light, a discharge cell emitting green light or a discharge cell emitting blue light at the time of its discharge is formed at each point of intersection between each row electrode pair and each column electrode inclusive of the discharge space.
Because the discharge cell causes light emission by utilizing the discharge phenomenon, it has only two states, that is, a "light-on state" in which the discharge cell emits light at predetermined luminance, and a "light-off state". In other words, the discharge cells can provide luminance of only two gradations. To achieve luminance display of an intermediate tone corresponding to input image signals by using such discharge cells, a driving apparatus for executing gradation driving in accordance with a sub-field method is disclosed in JP-A-2000-338932.
The sub-field method divides a display period of one field into N sub-fields and allocates in advance periods in which each discharge cell is allowed to continuously emit light (or to be turned off) to each sub-field. Each discharge cell is allowed to emit light or is turned off in accordance with the input image signal for each sub-field for the period allocated to the sub-field. It becomes possible in this way to express various kinds of intermediate luminance of 2N stages (N: number of sub-fields; hereinafter called "gradation") through combinations of the sub-fields that are to emit light during one-field period.
To accomplish gradation driving on the basis of the sub-field method described above, a driving apparatus (not shown in the drawings) applies various driving pulses to the PDP and causes various discharges in the discharge cells. In other words, the driving apparatus first applies a reset pulse to the row electrode pairs of the PDP and induces reset discharge in all the discharge cells. A predetermined quantity of wall charge is uniformly formed in all the discharge cells due to this reset discharge. Next, the driving apparatus causes serially and selectively erase discharge of the discharge cells in accordance with the input image signals for one horizontal scan line (hereinafter called "one display line"). In this instance, the wall charge remaining inside the discharge cells disappears in those discharge cells in which the selective erase discharge is induced. In those discharge cells in which the selective erase discharge is not induced, on the other hand, the wall charge created by the reset discharge remains as such. Next, the driving apparatus alternately and simultaneously applies sustain pulses the number of times corresponding to each sub-field to all the row electrode pairs. Only those discharge cells in which the wall charge remains repeatedly cause the sustain discharge for the period corresponding to the sub-field in accordance with the application of such sustain pulse and keep the light emission state resulting from this sustain discharge.
In the PDP, however, the quantity of the wall charge created by various kind of discharges does not-remain constant due to the temperature change of the panel, the shift of display luminance, the change with time, and so forth. For this reason, the PDP involves the problem that variance occurs in the intensity of discharge and display quality gets deteriorated.
To solve the problems described above, the invention aims at providing an apparatus for driving a display panel that can always execute quality image display.


An apparatus for polishing a semiconductor wafer is provided which includes a wafer carrier having on its lower surface a non-uniform surface structure means to vary the force against a wafer during a polishing operation so that the polishing is enhanced and imparts a planar surface across the polished wafer. Preferred non-uniform surface structure means include use of a wafer carrier having on its lower surface a backing film having a first central portion having a predetermined compressibility and a second peripheral portion having a different compressibility than the first portion. Another non-uniform surface structure means to vary the force against the wafer comprises a wafer carrier having on its lower surface a raised circumferential region around the periphery of the carrier.

1. Field of the Invention
The present invention relates to processing of semiconductor wafers such as slices of semiconductor silicon and, more particularly, to an improved method and apparatus for polishing the wafers in the chemical-mechanical planarization process in order to achieve a high degree of wafer planarity.
2. Problem to be Solved
In the manufacture of integrated circuits, wafer surface planarity is of extreme importance. Photolithographic processes are typically pushed close to the limit of resolution and it is essential that the wafer surface be highly planar so that the electromagnetic or other radiation used to create the integrated circuit may be accurately focused in a single level thus resulting in precise imaging over the entire surface of the wafer. Wavy, curved or wedge-shaped semiconductor disks result in lack of definition when, for example, a photosensitive resist is applied to the surface of the disk and exposed.
In order to achieve the degree of planarity required to produce ultra high density integrated circuits, chemical-mechanical planarization processes are now typically employed in the industry. In general, the chemical-mechanical planariztion (CMP) process involves pressing a semiconductor wafer against a moving polishing surface that is wetted with a chemically reactive, abrasive slurry. Slurries are usually either basic or acidic and generally contain alumina or silica particles. The polishing surface is typically a planar pad made of a relatively soft, porous material such as blown polyurethane. The pad is usually mounted on a planar platen.
In general, the wafer is secured to a carrier plate (or wafer carrier) by vacuum or by a mounting medium such as an adhesive, with the wafer having a force load applied thereto through the carrier by a pressure plate so as to press the wafer into frictional contact with a polishing pad mounted on a rotating turntable. The carrier and pressure plate also rotate as the result of either the driving friction from the turntable or rotation drive means directly attached to the pressure plate. In a typical polishing machine, the movement of the carrier is programmed to acquire a wafer from a first station, to transport the wafer to a polishing surface, to drive the wafer across the rotating polishing surface, to transport the wafer from the polishing surface to a second station, and to release the wafer at the second station. A typical way of securing and releasing the wafer is by the use of a vacuum head that includes a rigid perforated plate against which the wafer is drawn by applying a vacuum to a plenum lying above the perforated plate.
During polishing it has been found that when a load is imposed on the wafer the polishing action across the wafer is not uniform causing center-to-edge non uniformity in thickness and poor flatness of the wafer. The surface life of the polishing cloth is also a factor in effecting the planarity of the polished wafer. Frictional heat generated at the wafer surface enhances the chemical action of the polishing fluid and thus increases the polishing rate. The frictional head however can cause planarity problems unless the heat is evenly transmitted over the surface of the wafer and typical polishing systems utilize cooling systems to control the temperature of the polishing operation.
A number of attempts have been made in the prior art to improve the planarity of CMP operations. In U.S. Pat. No. 4,270,316 the uneven transmission of pressure which causes different degrees of abrasion of the polished disks is compensated for by the provision of soft elastic inserts placed between a pressure piston and the back of the carrier plate on which the disks to be polished are cemented. In U.S. Pat. No. 4,313,284 a deformable thin disk carrier is mounted through a resilient device to a rotatable pressure plate so that the carrier can be deformed to either a concave shape or convex shape depending on the polishing required. In U.S. Pat. No. 4,910,155 a dam is provided on the polishing plate so that the polishing pool of slurry completely immerses the polishing pad. In U.S. Pat. No. 4,918,869 the use of pressurized air acting on the pressure plate is provided so that the pressure on the wafer surface can be uniform. In U.S. Pat. No. 5,036,630 the wafer carrier comprises at least two (2) materials having different coefficients of thermal expansion which carrier imparts a desired convex or concave bias to the wafer during the polishing operation. In U.S. Pat. No. 5,423,716 the lower face of the backing plate of the wafer carrier includes a number of recessed areas to which a vacuum can selectively be applied. The vacuum is applied to suck a resilient membrane into the recessed areas to draw the wafer into position. The same apparatus can be used to apply a pressurized fluid to the wafer to exert a uniform downward pressure on the wafer. In U.S. Pat. No. 5,486,129 the pressure head of the wafer carrier contains a number of pressure applicators over the wafer surface which can be monitored and adjusted to vary the pressure on the wafer during the polishing operation.
In U.S. Pat. No. 5,232,875 a CMP apparatus is shown wherein the polishing pad is moved about in a plane parallel to the pad surface with either an orbital, fixed-direction vibratory or random-direction vibratory motion.
The disclosures of the above patents are hereby incorporated by reference.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an apparatus, e. g., CMP apparatus, for polishing semiconductor wafers and other workpieces.
It is another object of the present invention to provide an improved method for polishing workpieces, e. g., wafers, using such polishing operations as the CMP system.
It is an additional object of the invention to provide wafer carriers for use in CMP apparatus and CMP processes to enhance operation of the apparatus and improve the flatness of a polished wafer.
It is further object of the invention to provide flat workpieces, including semiconductor wafers, made using the improved method and apparatus of the invention.
Other objects and advantages of the present invention will be readily apparent from the following description.

CMP wafer carrier for preferential polishing of a wafer

International Business Machines Corporation


The polar surface area of molecules is computed without reference to three dimensional molecular structures using a linear equation incorporating counts of nitrogens, oxygens, and related atom clusters. Methods and systems for predicting intestinal absorption and blood brain barrier penetration of candidate compounds use the polar surface area and the octanol/water partition coefficient as descriptors.

1. Field of the Invention
The invention relates to computational methods of pharmaceutical discovery. Specifically, the invention relates to the prediction of membrane permeability and physiological absorption of molecules.
2. Description of the Related Art
In the development of pharmaceutical compounds, it is well known that identifying a compound with a desired biological activity is not itself sufficient to determine that compound's suitability as a drug. Not only must the compound exhibit the necessary biological activity, but it must also be deliverable to the target tissue(s), preferably in a cost effective and convenient manner such as oral administration. This has been a problem with several treatment protocols. For example, a wide variety of peptide molecules have been shown to have useful pharmacological activity, but their generally limited capacity to diffuse through biomembranes such as the human gastrointestinal epithelium has limited their clinical development. Effective oral administration requires that a drug be absorbed through the intestinal membranes to enter systemic circulation and if such absorption is limited, a compound's promise for clinical development is poor.
Not only is intestinal absorption an important concern during drug development, but the ability of a candidate compound to penetrate the blood-brain barrier is also of significant interest. The blood-brain barrier (BBB) is a cellular system that separates the fluids of the central nervous system from the circulatory system. Drugs intended for targets in the central nervous system should be able to penetrate the BBB. On the other hand, drugs intended for other target tissues may cause unwanted side effects if they freely pass into the fluids of the central nervous system.
In vivo animal testing for bioabsorption and blood-brain barrier penetration has long been practiced. In addition, a cell based in vitro assay using human intestinal caco-2 cells is in widespread use to measure the biomembrane permeability of drug candidate compounds. Because both of these protocols are slow, expensive, and labor intensive, computational methods to predict the potential for gastrointestinal absorption and blood-brain barrier penetration based on more easily obtained molecular characteristics have been developed. Also, such computational methods are of great interest for the in silico prediction of absorption and blood-brain barrier penetration for virtual libraries of compounds which have not been synthesized, for the purposes of determining which compounds should be synthesized. In these computational models, a formula for estimating either the % human intestinal absorption (% HIA) or the logarithm of the steady state ratio of the compound's concentration in the central nervous system and the blood (often called logBB) is constructed. The formula typically uses molecular properties and parameters that may be derived from the molecular structure of the compound. Using these formulas, % HIA and logBB may be estimated without the need to perform in vivo experiments.
Many models focus on molecular characteristics related to hydrogen bonding, lipophilicity, and molecular weight to predict propensity for intestinal absorption or blood-brain barrier penetration. A sigmoidal relationship between the polar surface area (PSA) of a molecule and its % HIA has been observed, with high polar surface area correlated to low % HIA. This is shown in Palm, et al. Polar Molecular Surface Properties Predict the Intestinal Absorption of Drugs in Humans, Pharmaceutical Research, Vol. 14, No. 5, p. 568 (1997). It has also been observed that molecules having either especially high or especially low octanol/water partition coefficients (logP), which is a measure of lipophilicity, are associated with low % HIA. Palm, supra, and Wils, et al., High Lipophilicity Decreases Drug Transport Across Intestinal Epithelial Cells, The Journal of Pharmacology and Experimental Therapeutics, Volume 269, No. 2, p. 654 (1994). The disclosures of both the Palm and Wils articles are hereby incorporated by reference in their entireties.
Accordingly, molecular PSA has been suggested as a parameter which can be used to distinguish between well absorbed and poorly absorbed compounds, with 140 square angstroms being proposed as a cutoff value. Clark, Rapid Calculation of Polar Molecular Surface Area and its Application to the Prediction of Transport Phenomena 1. Prediction of Intestinal Absorption, Journal of Pharmaceutical Sciences, Vol. 88, No. 8, p. 807 (1999). PSA has also been used as a variable in linear formulas for predicting membrane permeability and logBB. In some cases, logP is used along with PSA in such linear formulas. Clark, Rapid Calculation of Polar Molecular Surface Area and its Application to the Prediction of Transport Phenomena 2. Prediction of Blood-Brain Barrier Penetration, Journal of Pharmaceutical Sciences, Vol. 88, No. 8, p. 815 (1999) and Winiwarter, et al. Correlation of Human Jejunal Permeability (in Vivo) of Drugs with Experimentally and Theoretically Derived Parameters. A Multivariate Data Analysis Approach, Journal of Medicinal Chemistry 41, p. 4939 (1998), both of which are hereby incorporated by reference in their entireties.
Although these models have improved the speed of the drug candidate evaluation process by reducing reliance on in vivo and in vitro chemical testing, they remain computationally expensive, and in many cases, the strict linear modeling limits their predictive value. PSA calculations have required the calculation of energy minimized three dimensional molecular structures, which requires 10–15 seconds of CPU time on a Sun or SGI-R1000 workstation. The effective application of these techniques to large libraries of candidate compounds requires techniques which reduce the computation time required for each molecule.

Prediction of molecular polar surface area and bioabsorption


A microwave-assisted magnetic recording (MAMR) write head includes a yoke structure with a main pole, a flux return pole, and a trailing magnetic shield. The main pole includes a write pole with a tip at the disk-facing surface, a sub pole with an end recessed from the disk-facing surface and an electrically insulating layer between the write pole and the sub pole. The spin-torque oscillator (STO) is located at the disk-facing surface between the trailing shield and the write pole tip. The insulating layer assures that the STO current is not shorted between the return pole and the write pole. The insulating layer between the write pole and the sub pole increases the area of the junction between the return pole and write pole, which reduces the magnetic reluctance of the yoke structure.

1. Field of the Invention
This invention relates generally to magnetic recording systems, and more particularly to a write head with a spin-torque oscillator (STO) that provides microwave-assisted magnetic recording (MAMR).
2. Description of the Related Art
Perpendicular magnetic recording (PMR) in magnetic recording hard disk drives, wherein the recorded bits are stored in a perpendicular or out-of-plane orientation in the magnetic recording layer of the disk, allows for ultra-high recording density, i.e., the areal density of the recorded bits on the disk. However, an increase in recording density requires a corresponding reduction in the size of the magnetic grains in the magnetic recording layer to achieve sufficient medium signal-to-noise ratio. As the size of the magnetic grains is reduced, the magnetocrystalline anisotropy of the magnetic grains must be increased to maintain adequate thermal stability. Simultaneously, the magnetic write field from the write head has to exceed the coercivity of the magnetic recording layer to achieve saturation digital recording, resulting in a conflicted limitation on the anisotropy of the magnetic grains.
A PMR system with high-frequency assisted writing using a spin-torque oscillator (STO) has been proposed. This type of recording, also called microwave-assisted magnetic recording (MAMR), applies a high frequency oscillatory auxiliary magnetic field from the STO to the magnetic grains of the recording layer. The auxiliary field may have a frequency close to the resonance frequency of the magnetic grains in the recording layer to facilitate the switching of the magnetization of the grains at lower write fields from the conventional write head than would otherwise be possible without assisted recording. Conversely, MAMR may be used to increase the coercivity of the magnetic recording layer above that which could be written to by a conventional write head alone. The increase in coercivity afforded by MAMR allows for a reduction in the size of the magnetic grains and thus a corresponding increase in recording density system. MAMR systems are described in U.S. Pat. No. 6,785,092 B2; US 2008/0137224 A1; and by J. G. Zhu et al., "Microwave Assisted Magnetic Recording", IEEE Transactions on Magnetics, Vol. 44, No. 1, January 2008, pp. 125-131.
In proposed MAMR write heads, the STO is located between the write pole and the trailing magnetic shield. The STO is a multilayer film stack made up of two or more magnetic layers separated by a nonmagnetic spacer layer. One of the magnetic layers, the field generating layer (FGL), is designed to have its magnetization orientation oscillate in the presence of a direct electrical current perpendicular to the film planes of the film stack. In the presence of current above a critical current density, another magnetic layer, whose magnetization orientation preferably does not oscillate, acts as the "spin-polarizer" to produce a spin-polarized current at the FGL. This destabilizes the static equilibrium of the FGL's magnetization orientation, causing it to undergo sustained oscillation at frequencies useful for MAMR applications. The location of the STO between the write pole and the trailing shield may be the optimal location, if not the only possible location, to produce the necessary auxiliary field at the region of the recording layer where the magnetic write field from the write head is applied. Because electrical current for the STO is supplied through the magnetic yoke that surrounds the coil of the write head, there must be an insulating gap somewhere in the yoke to complete the electrical circuit. In proposed MAMR write heads, this insulating gap is located in the back region behind the coil and between a portion of the yoke and the write pole. However, this location provides a relatively narrow flux path and thus increases the magnetic reluctance of the magnetic circuit, which means that higher write current and frequency response are required to achieve the desired magnetic write field.
What is needed is a MAMR write head that provides an electrically conductive path for the STO current but with a minimal increase in magnetic reluctance so as to not require an increase in write current.

Microwave assisted magnetic recording (MAMR) write head and system


The invention relates to novel 2-Oxy, 2-Amino, and 2-Thio-imidazole compounds of formula (I):

Histamine [2-(imidazol-4-yl)ethylamine] is a transmitter substance. Histamine exerts a physiological effect via multiple distinct G-protein coupled receptors. It plays a role in immediate hypersensitivity reactions and is released from mast cells following antigen IgE antibody interaction. The actions of released histamine on the vasculature and smooth muscle system account for the symptoms of the allergic response. These actions occur at the H1 receptor (Ash, A. S. F. and Schild, H. O., Br. J. Pharmacol., 1966, 27, 427) and are blocked by the classical antihistamines (e.g. diphenhydramine). Histamine is also an important regulator of gastric acid secretion through its action on parietal cells. These effects of histamine are mediated via the H2 receptor (Black, J. W., Duncan, W. A. M., Durant, C. J., Ganellin, C. R. and Parsons, E. M., Nature, 1972, 236, 385) and are blocked by H2 receptor antagonists (e.g. cimetidine). The third histamine receptor —H3— was first described as a presynaptic autoreceptor in the central nervous system (CNS) (Arrang, J.-M., Garbarg, M., and Schwartz, J.-C., Nature 1983, 302, 832) controlling the synthesis and release of histamine. Recent evidence has emerged showing that the H3 receptors are also located presynaptically as heteroreceptors on serotonergic, noradrenergic, dopaminergic, cholinergic, and GABAergic (gamma-aminobutyric acid containing) neurons. These H3 receptors have also recently been identified in peripheral tissues such as vascular smooth muscle. Consequently there are many potential therapeutic applications for histamine H3 agonists, antagonists, and inverse agonists. (See: "The Histamine H3 Receptor-A Target for New Drugs", Leurs, R., and Timmerman, H., (Editors), Elsevier, 1998; Morisset et al., Nature, 2000, 408, 860-864.) A fourth histamine receptor —H4— was recently described by Oda et al., (J. Biol. Chem., 2000, 275, 36781-36786).
The potential use of histamine H3 agonists in sleep/wake and arousal/vigilance disorders is suggested based on animal studies (Lin et al, Br. Res., 1990, 523, 325; Monti et al Eur. J. Pharmacol., 1991, 205, 283). Their use in the treatment of migraine has also been suggested (McLeod et al Abstr. Society Neuroscience, 1996, 22, 2010) based on their ability to inhibit neurogenic inflammation. Other applications could be a protective role in myocardial ischemia and hypertension where blockade of norepinephrine release is beneficial (Imamura et al J. Pharmacol. Expt. Ther., 1994, 271, 1259). It has been suggested that histamine H3 agonists may be beneficial in asthma due to their ability to reduce non-adrenergic non-cholinergic (NANC) neurotransmission in airways and to reduce microvascular leakage (Ichinose et al Eur. J. Pharmacol., 1989, 174, 49).
Several indications for histamine H3 antagonists and inverse agonists have similarly been proposed based on animal pharmacology experiments with known histamine H3 antagonists (e.g. thioperamide). These include, dementia, Alzheimer's disease (Panula et al Abstr. Society Neuroscience, 1995, 21, 1977), epilepsy (Yokoyama et al Eur. J. Pharmacol., 1993, 234, 129) narcolepsy, eating disorders (Machidori et al Brain Research 1992, 590, 180), motion sickness, vertigo, attention deficit hyperactivity disorders (ADHD), learning and memory (Barnes et al Abstr. Society Neuroscience, 1993, 19, 1813), schizophrenia (Schlicker et al Naunyn-Schmiedeberg's Arch. Pharmacol., 1996, 353, 290-294); (also see; Stark et al Drugs of the Future, 1996, 21, 507 and Leurs et al Progress in Drug Research, 1995, 45, 107 and references cited therein). Histamine H3 antagonists, alone or in combination with a histamine H1 antagonist, are reported to be useful for the treatment of upper airway allergic response (U.S. Pat. Nos. 5,217,986; 5,352,707 and 5,869,479). Recently, a histamine H3 antagonist (GT-2331) was identified and is being developed by Gliatech Inc. (Gliatech Inc. Press Release Nov. 5, 1998; Bioworld Today, Mar. 2, 1999) for the treatment of CNS disorders.
As noted, the prior art related to histamine H3 ligands was comprehensively reviewed recently ("The Histamine H3 Receptor-A Target for New Drugs", Leurs, R., and Timmerman, H., (Editors), Elsevier, 1998). Within this reference the medicinal chemistry of histamine H3 agonists and antagonists was reviewed (see Krause et al and Phillips et al respectively). Thus the importance of an imidazole moiety containing only a single substitution in the 4 position was noted together with the deleterious effects of additional substitution on activity. Particularly methylation of the imidazole ring at any of the remaining unsubstituted positions was reported to strongly decrease activity.
More recently several publications have described histamine H3 ligands that do not contain an imidazole moiety. For example; Ganellin et al Arch. Pharm. (Weinheim, Ger.) 1998, 331, 395; Walczynski et al Arch. Pharm. (Weinheim, Ger.) 1999, 332, 389; Walczynski et al Farmaco 1999, 684; Linney et al J. Med. Chem. 2000, 2362; Tozer and Kalindjian Exp. Opin. Ther. Patents 2000, 10, 1045-1055; U.S. Pat. No. 5,352,707; PCT Application WO99/42458, Aug. 26, 1999; and European Patent Application 0978512, Feb. 9, 2000.
We now describe a series of heterocyclic derivatives with the ability to modulate the activity of the histamine receptor, specifically the H3 receptor.

2-oxy, 2-amino, and 2-thio-imidazole compounds

Abstract: wherein all variables are as herein defined, pharmaceutical compositions containing the compounds and methods of using them in the treatment of neurological disorders and other disorders and conditions mediated by the histamine H3 receptor.


An X-ray tube includes a cathode, an anode, and a deflection device. The cathode and the anode generate an electron beam that is directed toward a target area of the anode to generate X-ray radiation through electrons of the electron beam impinging the target area. The deflection device controls the electron beam such that the electrons hit the anode at different focal spot positions. The deflection device provides gradual deflection for a stepless transition between monoscopic viewing and stereoscopic viewing. For monoscopic viewing, the X-ray radiation is generated from a single focal spot position. For stereoscopic viewing, the X-ray radiation is generated from two focal spot positions spaced apart in a first stereo-direction transverse to a viewing direction. The deflection device provides gradual deflection for a stereo focal spot position in a second stereo-direction, which is transverse to the first stereo-direction and the viewing direction.

For providing depth information of an object, X-ray stereo imaging is used, for example in medical imaging. However, it has been found that, although stereo imaging provides useful depth information, the user, for example a physician, maintains and sometimes even prefers monoscopic viewing techniques. The switching to stereo imaging is hence sometimes avoided. Thus, additional depth information is sometimes not made visible to the user. US 2010/0067662 describes a stereo rotating anode X-ray tube.

Gradual X-ray focal spot movements for a gradual transition between monoscopic and stereoscopic viewing


A content-addressable memory (CAM) with computational capability is described. The CAM includes an array of CAM cells arranged in rows and columns with a pair of search lines associated with each column of the array and a match line associated with each row of the array. The array of CAM cells is configured to implement, for a given cycle, either a read operation of data contained in a single selected column, or one of a plurality of different bitwise logical operations on data contained in multiple selected columns. All of the pairs of search lines in the columns of the array are configured to a certain state to implement the read operation or one of the plurality of different bitwise logical operations. A result of the read operation or one of the plurality of different bitwise logical operations is outputted onto all of the match lines in the array.

The present invention relates generally to integrated circuit memory devices and, more particularly, to a computational memory implemented from a content addressable memory (CAM) such as a ternary CAM (TCAM).
Existing computer designs typically provide a direct connection between a processor and its associated memory components. In conventional designs, data values are exchanged between the processor and the memory components, which contain load/store addresses and load/store data objects going in and out of the processor.
In order to improve the computational power of processors such as microprocessors, a processing element or arithmetic logic unit (ALU) may be positioned as close as possible to the source of the data (e.g., a memory array) to promote a high data bandwidth between the two structures. Thus, modern microprocessors commonly feature large capacity memories next to the ALU in the form of, for example, L1 , L2 and other caches. Although this added memory improves performance, it also increases the die area, and thus, the cost of each microprocessor chip.
Other attempts at increasing the computational speed of a processing element involve placing a one-bit SIMD (Single-Instruction Stream Multiple-Data Stream) processor within the memory circuitry, adjacent to sense amplifiers in both SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory) arrays. However, for small memories, the overhead of this bit-wise ALU approach is high. In addition, the operands need to be read out one at a time, and only then can the result be computed in the ALU attached to the sense-amplifier.

Implementing computational memory from content-addressable memory

International Business Machines Corporation


An improved structure of a computer housing comprising a front side board, a rear side board, a top side board, a bottom side board, a left side board, and a right side board, characterized in that a plurality of pivot members are hingedly disposed along the edges of the respective side boards, the side boards having one edge adjacent to other side boards, a plurality of securing seat plates are provided on the from side board for the mounting of a optical disc, a hard disc and soft disc, a holding seat plate is disposed on the rear side board for the mounting of a power source supply, and a plurality of the pivot members are formed along one edge of the front side board and a rear side board such that the computer housing can be spread out on as a flat plan. The present computer housing requires a small space for transportation and therefore the cost of transportation is greatly saved. In addition, the present invention provides a convenient installation and maintenance.

(a) Field of the Invention
The present invention relates to computer housing, and in particular, a computer housing having a front side board, a rear side board, a top side board, a bottom side boards, etc being pivotally hinged with other at the adjacent edges of the boards, thereby, a comparative smaller space is required during shipping of the housing and the housing facilitates maintenance of the computer.
(b) Description of the Prior Art
Referring to FIG. 1, there is shown a conventional computer housing comprising a front side board 10, a rear side board 11, a covering plate 12 and a base plate 13. The front side plate 10 is provided with a plurality of slots 100 to mount with a securing plate so as to mount an optical disc, a hard disc and a soft disc. A through hole 110 is provided on the rear side board 11 and is associated with a holding plate to hold a power supply. The covering plate is substantially an inverted "U" shaped and a protruded disc plate 120, bending inward, being provided at the bottom section of the two sides. The base plate 13 is a rectangular shape disc-like member.
In order to assemble the essential parts of a computer, these parts, such as the optical disc, hard disc and the soft disc are respectively mounted at the front side board 10 and the rear side board 11 or in between, and the bottom side of the front side board 10 and the rear side board 11 are mounted at the two side edges of the base plate 13, Then, the opening of the covering plate 12 is opened and the and the rear side board 11 is pushed forward to the front side board 10 until it is all covered. Finally, screws are used to mount the two sides of the base plate 13 at the protruded plate 120 of the covering plate 12.
Such computer housing has the following drawbacks in assemble and in use:                (a) The volume of the housing is large and the transportation cost is high: As the computer housing has a covering plate 12 and is substantially inverted "U" shaped, therefore, the computer housing occupies a larger space and the cost of transportation is increased.        (b) Assembly and maintenance of the computer are not easy. The entire housing has to be placed downward and to detach the base plate 13 and the covering plate 12 in order to access to the interior of the computer.


An optical module includes a mounting board, an optical element, an optical fiber having an optical axis, the optical fiber inserted in the mounting board to align the optical axis with the optical element, and a positioning mark provided to position the optical element on the mounting board. The mounting board has a groove provided in the middle of the mounting board and extending in a direction of the optical axis of the optical fiber, the groove enclosing the optical fiber when inserted. The groove has a vertical wall which is perpendicular to the direction of the optical axis and confronts a leading edge of the optical fiber when inserted. The positioning mark is located adjacent to an internal edge of the groove where the vertical wall is provided on the mounting board.

(1) Field of the Invention
The present invention relates to an optical module having an optical element, such as a laser-diode or a photo-diode, connected to an optical fiber, and to a method of producing the optical module. More particularly, the present invention relates to an optical module in which the optical element is supported on a mounting board and connected to an optical fiber.
Recently, optical fiber transmission has made great progress. The optical fiber transmission has various advantages including transmission of a large amount of data, a low level of loss, no cross talk, no radiation and the like. In order to develop an optical fiber transmission system for practical use, it is important that optical parts, like the optical module, which constitute a part of the optical fiber transmission system, have high reliability and good productivity.
(2) Description of the Related Art
FIGS. 1A, 1B and 1C show a conventional optical module. Referring to FIGS. 1A, 1B and 1C, an insulating layer 7 is formed on a mounting board 1.
The mounting board 1 is comprised of a silicon (Si) substrate, and the insulating layer 7 is a silicon dioxide (SiO.sub.2) film. A metal layer 2 is formed on the insulating layer 7 as shown in FIG. 1A. A V-groove 4 is formed in the middle of the mounting board 1, the V-groove 4 extending in a longitudinal direction of the mounting board 1. An optical fiber 8 is enclosed by the V-groove 4. The V-groove 4 extends in a direction of the optical axis of the optical fiber 8.
FIG. 1B is an enlarged view of a portion of the conventional optical module where a laser-diode (LD) 3 and the optical fiber 8 are connected. As shown in FIG. 1B, a solder layer 9 is formed adjacent to an end of the V-groove 4, and the solder layer 9 is used to fix the laser-diode (LD) 3 to the mounting board 1. An electrode 5 is formed on the insulating layer 7. The electrode 5 is made of gold (Au). The electrode 5 is connected to and taken out from the solder layer 9, and the electrode 5 extends from the end of the solder layer 9 in the longitudinal direction of the mounting board 1.
The laser-diode (LD) 3 is positioned at a packaging location 10 on the mounting board 1 to correctly perform the coupling of the laser-diode 3 and the optical fiber 8 with respect to the direction of the optical axis of the optical fiber 8. The packaging location 10 is indicated by a dotted line in FIG. 1B, and it surrounds the periphery of the solder layer 9. A positioning mark 11 is provided on the mounting board 1 and attached to the electrode 5, and the positioning mark 11 is used to indicate the packaging location 10 for positioning the laser-diode 3 on the mounting board 1 at a proper location. The positioning mark 11 has a rectangular shape, and it is located at an opposite side to a side of the packaging location where the V-groove 4 is formed.
FIG. 1C is a cross-sectional view of the portion of the conventional optical module shown in FIG. 1B. As shown in FIG. 1C, the V-groove 4 has a sloping wall 4a which confronts the leading edge of the optical fiber 8. Since the sloping wall 4a of the V-groove 4 comes in contact with the optical fiber 30 when the optical fiber 8 is placed in the V-groove 4 to approach the laser-diode 3, the conventional optical module requires a certain amount of gap 12 between the laser-diode (LD) 3 and the optical fiber 8. To reduce the gap 12 between the LD 3 and the optical fiber 8, it is necessary that the packaging position of the LD 3 on the mounting board 1 is a position at which the LD 3 projects from the end of the V-groove 4 toward the V-groove 4, as shown in FIG. 1C.
If the positioning mark 11 is located adjacent to the V-groove 4, the positioning mark 11 is concealed by the LD 3 and it cannot be used to position the LD 3 on the mounting board 1 during the assembly.
The V-groove 4 is formed by etching of the silicon board 1, and the V-groove 4 has to include a sloping surface. This sloping surface depends on the characteristics of the silicon crystal structure of the silicon board 1. The sloping surface of the V-groove 4 confronts the leading edge of the optical fiber 8 when inserted.
The above conventional optical module, shown in 1A, 1B and 1C, has a problem, that is, it is difficult to perform the positioning of the laser-diode 3 to the optical fiber 8 with high accuracy. To perform the positioning of the laser-diode 3, one must observe the positioning mark 11 which is located at the opposite side to the side of the packaging location 10 where the V-groove 4 is formed. In particular, it is very difficult to achieve a required level of accuracy of the positioning of the laser-diode 3 by eliminating a misalignment or rotation of the laser-diode 3 with respect to the direction of the optical axis of the optical fiber 8. Since the positioning of the optical element on the mounting board is difficult to perform, the conventional optical module produced by using the above production method is not reliable, and the productivity of the thus produced optical module is low.

Optical module for connecting optical element and optical fiber


A uniplanar medical steering device which includes a tubular member of a material such as stainless steel, a hinge formed by a cut-out in a wall of the tubular member and a control wire for bending a first end of the tubular member back and forth in a plane towards and away from a second end of the tubular member. A medical device such as a catheter can be provided within the tubular member and an outer member surrounding the tubular member can be used to cover the cut-out. The steering device allows accurate positioning of a medical device and prevents twisting of the medical device when bent by the control wire.

1. Field of the Invention
The invention relates to an articulating device and method of manufacture thereof. In addition, the invention relates to the use of the articulating device for steering medical devices such as the distal portion of medical devices typically used in minimally invasive surgery.
2. Description of Related Art
Rigid instruments, which may, for example, be catheters, graspers, or other tools, limit the ability of the surgeon to access the interior portions of the body. By having articulateable distal portions this adds an extra degree of freedom, thus reducing the need for changing tools during a procedure, and as a result reducing the time needed for the procedure to the mutual benefit of surgeon and patient alike.
As already stated the majority of tools used in these procedures are rigid. There are a variety of devices which have a degree of steerability added via a fixed curve being introduced in the distal end, and some devices which have steerable tips. Examples of steerable tips can be found in commonly owned and copending application Ser. No. 07/903,587 and U.S. Pat. No. 4,934,340 ("Wendel"), and U.S. Pat. No. 5,114,403 ("Clarke"). In many of these devices the distal tip, on being articulated, suffers from a problem commonly described as "S-ing". This term refers to the tendency for the articulating portion of the device to take on an S-shape, in which it no longer lies in a single plane. This is particularly problematical in small diameter devices wherein it is not possible to add stiffening members to alleviate this. The current invention offers a means of producing small diameter devices which freely articulate but have no tendency to "S". Additionally, for the aforementioned types of surgical devices it is frequently highly desirable that the tip be able to support significant end loading in the bent (or articulated) state. Existing devices generally do not provide such strength.
Various devices are known for steering medical devices such as catheters. For instance, steering mechanisms are discussed in U.S. Pat. Nos. 4,353,358 ("Emerson"); 3,470,876 ("Barchilon") and 4,245,624 ("Komiya").
U.S. Pat. No. 4,353,358 ("Emerson") discloses a disposable sigmoidoscope having a tubular portion of plastic material wherein a free end is weakened by providing one or more cut-outs or notches or by making the side of the tubular portion thinner. An operator cord member of wire, plastic or string member is attached to the free end and extends along the outer surface of the segments between the cut-outs, on the inside of the segments or through the weakened side of the device. Pulling on the member allows the tubular member to be bent somewhat but not so much that the operator can no longer see through the passage through the tubular member. A protective outer layer or sheath covers the cut-outs in order to prevent discomfort to the patient during insertion and withdrawal of the device and prevent material from entering the device through the cut-outs.
U.S. Pat. No. 3,470,876 ("Barchilon") discloses a 1/8 to 2 inch diameter catheter including an outer tube, an inner tube and a rigid end piece connecting the distal ends of the inner and outer tubes. The end piece has a flange and four tensioning cords are attached thereto such that each cord is offset 90.degree. with respect to each other. The inner and outer tubes are of flexible material such as a silicone compound having a durometer of 48. The cords are of material such as wire or nylon and the catheter can be bent in any desired direction by pulling on one or more of the cords.
U.S. Pat. No. 4,245,624 ("Komiya") discloses an endoscope having an observation optical system, a flexible plastic guide tube and a wire, each of which is located in a respective one of three channels extending longitudinally through a distal end of the endoscope. The guide tube is movable longitudinally beyond the distal end of the endoscope and the wire is attached to a distal end of the guide tube for bending the guide tube. When the guide tube is empty, liquid can be sprayed from or sucked into the distal end thereof. On the other hand, a medical implement such as forceps can be inserted into the guide tube and the wire can be used to bend the guide tube and medical implement toward a prescribed location in a body cavity. The guide tube can be made more flexible by using a plastic material foamed at a progressively higher rate at the distal end thereof. Alternatively, the guide tube can be made thinner at the distal end thereof or the guide tube can be surrounded by a coil of plastic or metal which has a progressively larger pitch toward the distal end of the guide tube.
It would be desirable in the medical field to have a steering device which prevents S-ing and instead allows accurate uniplanar bending of a distal end of a medical device. It is further desirable that such a steering device be capable of sustaining significant end-loading forces in the articulated state.


An image reading lens includes a plurality of lenses, a first correcting mechanism that corrects a field curvature at a first correction part when temperature changes, and a second correcting mechanism that corrects an image-forming position when the temperature changes. The second correcting mechanism corrects the image-forming position at a part where a positional displacement of the image-forming position caused by a change of a lens interval is greater and a variation of the field curvature caused by the change of the lens interval is smaller than the first correction part.

Technical Field
The present invention relates to an image reading device, such as an image scanner, and an image reading lens adapted to read an original image as a part of an image forming apparatus, such as a facsimile and a digital copying machine. Further, the present invention relates to an image forming apparatus including the image reading device.
Description of Related Art
Image reading devices, which are installed into image scanners, facsimiles, digital copying machines or the like to read original images, are configured to form reduced optical images using image reading lenses and to photograph the reduced optical images by solid-state image pickup elements (e.g., CCD image sensors) so as to make the images into electronic image data. Further, to read the original images as color images, the solid-state image pickup elements are configured with so-called three-line CCD image sensors having light-receiving elements arranged in three lines. Each of the light-receiving elements includes, for example, a red filter, a green filter, and a blue filter. By forming the reduced optical images of the original documents onto the light-receiving surfaces of the solid-state image pickup elements, the image reading devices perform color separation of the images into three primary colors and convert the color image data into signals. In general, the image reading lenses are required to have a high contrast in a high special frequency region on the image plane and a high aperture efficiency up to the periphery part of a viewing angle. Additionally, in order to appropriately read color original documents, the image-forming positions in the optical direction of the primary colors, i.e., red, green and yellow, on the light-receiving surfaces need to be identical to each other. That is, the chromatic aberration of each primary color needs to be corrected accurately.
On the other hand, in order to downsize the image reading devices and to accelerate image reading speed thereof, heating value in the vicinity of the photographing part such as the CCD image sensors increases. Further, in order to increase illuminance of light sources to illuminate the original images, the heating value of the light source also increases. As a result, the temperature inside the image reading device increases, and thus the performance of the devices may be deteriorated. Patent Literature 1 (JP2014-174415 A) discloses an image reading lens to restrain the deterioration of the performance caused by temperature changes.

Image reading lens, image reading device, and image forming apparatus