Abstract: A method for improving the radial enlargeability and other properties of tape-reinforced tubular vascular graft formed of sintered fluoropolymer(s), such as expanded, sintered PTFE. Broadly, the method comprises the step of radially shrinking the reinforcement tape layer of the graft, or the entire tape-reinforced graft, after sintering thereof. Such radial shrinkage of the reinforcement tape layer, or of the entire graft, renders the graft subsequently radially enlargeable by more than 5%, without tearing or breaking of the reinforcement tape layer of the graft. Radially enlargeable grafts of the present invention may be combined with various types of stents or anchoring systems, to form endovascular graft devices which are transluminally insertable and implantable within the lumen of a host blood vessel.

Abstract: An apparatus and method for temporarily implanting an intraluminal stent in a body lumen and its subsequent removal. A stent is formed from a thin sheet that has been wound around itself into a generally cylindrical roll. The stent has a deployed configuration with a deployed diameter generally the size of the lumen diameter. The stent has a delivery configuration, formed by winding the stent more tightly than the deployed configuration, with the delivery diameter smaller than the deployed diameter in order to allow low profile delivery into the body lumen. The stent will transform from the delivery configuration to the deployed configuration when exposed to body heat. The stent can be deployed by an intraluminal delivery catheter that secures the stent in its delivery configuration during intraluminal delivery of the stent. The stent can be removed from the body lumen via a removal catheter that coils the stent into a sheath at the end of the removal catheter.

Abstract: A method for improving the radial enlargeability and other properties of tape-reinforced tubular vascular graft formed of sintered fluoropolymer(s), such as expanded, sintered PTFE. Broadly, the method comprises the step of radially shrinking the reinforcement tape layer of the graft, or the entire tape-reinforced graft, after sintering thereof. Such radial shrinkage of the reinforcement tape layer, or of the entire graft, renders the graft subsequently radially enlargeable by more than 5%, without tearing or breaking of the reinforcement tape layer of the graft. Radially enlargeable grafts of the present invention may be combined with various types of stents or anchoring systems, to form endovascular graft devices which are transluminally insertable and implantable within the lumen of a host blood vessel.

Abstract: A system for delivering a probe into a body part to perform a therapeutic or diagnostic procedure therein which includes an elongated probe device which is disposed within a protective sheath and which has a rotary drive unit connected to its proximal extremity to rotate the probe about its longitudinal axis, preferably at a rate above 50 rpms while applying axial pressure thereto to cause the distal end of the probe to penetrate through the patient's tissue to a desired location in the body part where the procedure is to occur. In a presently preferred embodiment, the probe is an optical fiber which is delivered into a male patient's prostate gland through the patient's prostatic urethral wall. The optical fiber is optically connected to a source for laser energy (815 nm) which is emitted from the distal end of the optical fiber to ablate prostatic tissue surrounding the distal end.

Abstract: A method and system for removing an organ or piece of tissue severed from its supporting tissue within a patient's body cavity, such as the abdominal cavity, which includes an elongated expandable tubular member with a sealed interior. In one preferred embodiment for morcellation, means are provided within the sealed interior to tear or cut off tissue fragments from the organ or tissue which are small enough to pass out of the patient's body cavity through an inner lumen of an exit trocar sheath disposed within the patient and in communication with the body cavity. The organ or piece of tissue is placed within an inner lumen defined by the sealed interior through an opening provided in a leading portion of the elongated expandable tubular member. The organ or piece of tissue is fragmented into smaller pieces which are withdrawn from the patient's body cavity by the passage of the morcellation system through the inner lumen of the exit trocar sheath.

Abstract: The amount of electrically conductive material in the bottom floor lining of a conventional aluminum reduction cell is reduced by using a non-conductive lining material in its place. The non-conductive material separates the remaining electrically conductive regions from the sidewall linings of the cell and preferably confines the electrically conductive material to the "anode shadow" region of the cell floor. In another embodiment joints between the conductive and non-conductive regions are positioned such that they are covered by cell freeze (solid electrolyte) during operation of the cell. This prevents liquid cell contents penetrating the joint and adversely affecting the cell lining, thus shortening the life of the cell. The non-conductive material preferably comprises a particulate alumina mixture made up of large shapes which firmly compact together and smaller particles which fill the remaining voids.

Abstract: The amount of electrically conductive material in the bottom floor lining of a conventional aluminum reduction cell is reduced by using a non-conductive lining material in its place. The non-conductive material separates the remaining electrically conductive regions from the sidewall linings of the cell and preferably confines the electrically conductive material to the "anode shadow" region of the cell floor. The non-conductive material preferably comprises a particulate alumina mixture made up of large shapes which firmly compact together and smaller particles which fill the remaining voids. Optionally, the mixture may be bonded together with amorphous alumina, in which case the mixture can also be used for cell wall linings. The linings can be used in reduction cells of conventional design and reduces undesirable magnetohydrodynamic effects as well as pollution hazards caused by conventional carbonaceous cell linings.

Abstract: A valve (20) has a valve housing (22) with a central passage (28) extending axially through the valve housing (22). Aperture (40) in the valve housing connect a second passage (38) to the central passage (28) to extend through the valve housing. A poppet valve member (24) is configured for sealing engagement of the central passage (28). The valve member (24) is urged into sealing engagement with the central passage (28) by internal pressure in a container (36) on which the valve (20) is provided. The valve member (24) and the valve housing (22) are configured so that the valve member (24) will drop away from sealing the central passage (28) when the pressure in the container (36) is insufficient to hold the valve member (24) in sealing position against the central passage (28) to leave the valve (20) in a permanently open state. An annular valve member (26) seals the second passage (38 ) in the same manner.

Abstract: The amount of electrically conductive material in the bottom floor lining of a conventional aluminum reduction cell is reduced by using a non-conductive lining material in its place. The non-conductive material separates the remaining electrically conductive regions form the sidewall linings of the cell and preferably confines the electrically conductive material to the "anode shadow" region of the cell floor. The non-conductive material preferably comprises a particulate alumina mixture made up of large shapes which firmly compact together and smaller particles which fill the remaining voids. Optionally, the mixture may be bonded together with amorphous alumina, in which case the mixture can also be used for cell wall linings. The linings can be used in reduction cells of conventional design and reduces undesirable magnetohydrodynamic effects as well as pollution hazards caused by conventional carbonaceous cell linings.

Abstract: A valve assembly (52) has a valve housing (64) which fits in neck (76) of container (50). Valve member (88) is slidably movable in housing (64). Housing (64) has a plurality of grooves (86) and apertures (80), which interact with flanges (92, 94, 96) to define flow paths in the valve assembly (52). The flanges (92, 94, 96), inside surface (84), apertures (80), slots (86) and valve member (88) provide a flow path through the valve assembly (52) when the valve member (88) is in its downward position inside housing (64) and seal the flow path when the valve member (88) is in its upward position. A spring (102) urges the valve member (88) to its upward position.

Abstract: A valve, suitable for use in small medical devices and which can readily be made of medical grade materials, comprises an elastic diaphragm stretched over a protruding surface, preferably of spherical or convex shape. The diaphragm has a ring of holes concentrically around a hole in the protruding surface. A mating recess, connected to a conduit, fits over the protruding surface. The elastic material is held in place at or near the opening of the recess. The holding structure may also serve to seal the valve. A dual arrangement provides an input and an output valve in combination.

Abstract: In an electrolytic reduction cell in which molten metal is produced by electrolysis of a molten electrolyte, less dense than the molten metal product, the molten product metal collects at the bottom of the cell. A filter is provided at this location and is constructed from a material which is resistant to attack by both the molten metal and molten electrolyte, and which is wetted by the molten metal, but not by the electrolyte. By correcting sizing of the passage or passages in the filter molten metal product can be drawn out of the cell without simultaneous withdrawal of molten electrolyte. In the case of a cell for the production of aluminium the filter is preferably constructed from titanium diboride.

Abstract: In an electrolytic reduction cell for the production of molten metal, particularly aluminium, by electrolysis of a less dense salt monolayer of ceramic shapes is located on the floor of the cell. Such shapes are formed of a ceramic material, wettable by molten aluminium, but not wettable by the cell electrolyte. The spacing between adjacent shapes and/or the apertures in individual shapes is selected such that interfaced surface forces prevent entry of electrolyte between the shapes. The shapes may be tiles, honeycombs, cylinders, tubes, balls etc. The product metal may be collected in a sump for periodic withdrawal from the cell or withdrawn continuously or at short intervals through a selective filter that permits passage of molten metal, but not of molten cell electrolyte, at low withdrawal rates.

Abstract: An improved fiber optic matrix coding method and apparatus for a radiation image amplifier is disclosed. The improved method and apparatus permits the determination of the location of detected incident radiation to within an area approximately equal to the cross-sectional area of one of the optical fibers in the coding matrix, thereby providing a four-fold reduction in the number of optical fibers currently required to obtain a radiation image of comparable resolution. The improved method and apparatus also yields a four-fold improvement in the resolution of the timing pulse, thereby permitting the achievement of correspondingly higher rates for processing radiation image data.

Abstract: A method and apparatus for producing images which may be viewed in three dimensions by use of a stereoscope. In one embodiment, the object to be viewed containing annihilation radiation is placed between a plurality of radiation detectors. The detectors generate signals indicative of the coordinate positions from which the radiation photons originate. These signals are used to display images of the object that can be viewed stereoscopically through a stereoscope. The images may be displayed on two different displays or on a single display in two different colors.