Abstract: A throttle valve includes a valve body defining a flow passage. A plurality of non-overlapping occluder members are mounted in the flow passage and have synchronized movement due to devices externally of the flow passage. The occluder members have mating edges which engage when closed together to substantially restrict flow through the passage. The occluder members are movable to multiple open positions wherein the mating edges are spaced apart to permit unobstructed and centralized flow through the passage.

Abstract: A heart valve holder-inserter (21, 121) is designed to facilitate easy implantation of a mechanical heart valve prosthesis (23, 123). This holder-inserter, at its distal end, incorporates a pair of diametrically opposed guide members (47, 49, 81, 147, 149) which extend well beyond the leading edge of the prosthesis and which have exterior surfaces (53, 83, 153) of substantial dimension that are smoothly curved and proportioned so as to slowly spread the tissue annulus in order to facilitate easy entrance thereinto of the leading edge portion of the mechanical valve body.

Abstract: A prosthetic heart valve is shown which incorporates a valve body design and leaflet pivot arrangements that minimize turbulence and shear stresses having a tendency to generate thrombosis. A valve body having an axially curved entrance that is smoothly joined to a generally cylindrical body of extended axial length provides excellent fluid flow characteristics when combined with leaflets that can assume orientations perfectly aligned with the downstream flow of blood. By constructing such a pyrocarbon valve body which receives a metal ring at an appropriate location, suture rings that permit the tissue annulus to directly contact the exterior surface of the cylindrical valve body are accommodated.

Abstract: A prosthetic heart valve is shown which incorporates a valve body design and leaflet pivot arrangements that minimize turbulence and shear stresses having a tendency to generate thrombosis. A valve body having an axially curved entrance that is smoothly joined to a generally cylindrical body of extended axial length provides excellent fluid flow characteristics when combined with leaflets that can assume orientations perfectly aligned with the downstream flow of blood. By constructing such a pyrocarbon valve body which receives a metal ring at an appropriate location, suture rings that permit the tissue annulus to directly contact the exterior surface of the cylindrical valve body are accommodated.

Abstract: A bileaflet heart valve incorporates a pivot arrangement that minimizes resistance to downstream blood flow in the open position yet has prompt response and therefore minimal regurgitation upon flow reversal. A valve body having an axially curved entrance that smoothly joins a generally cylindrical body of extended axial length provides excellent fluid flow characteristics when combined with leaflets that can assume orientations perfectly aligned with the downstream flow of blood. Identical flat leaflets can assume a parallel orientation in the fully open position during downstream blood flow or can assume other low energy positions. Flat ears, which extend laterally from opposite surfaces of the leaflets, interengage with cavities of unique design having upstream and downstream lobes separated by an intermediate throat portion defined by inward and outward fulcrums.

Abstract: Bi-axial implants for the replacement of human joints which require multi-axis rotation and translation as well as for the replacement of anatomical ball and socket joints. A first member has a fixation element such as a stem for affixation to a first bone and a convex head, which head is received in a cavity in a second member having a concave surface which member is designed for attachment to a second bone. Located between the convex and concave surfaces is a ring bearing which forms a circular line of contact with the convex head and a circular line of contact with the concave surface. When a load is applied and transferred between the first and second members, the position of the ring bearing shifts to an alignment substantially transverse to the direction in which the load is being applied.

Abstract: A bileaflet heart valve is shown which incorporates a pivot arrangement that minimizes resistance to downstream blood flow in the open position yet has prompt response and therefore minimal regurgitation upon flow reversal. The valve employs a pair of identical flat leaflets that can assume a precisely parallel orientation in the fully open position at or near peak downstream blood flow or can alternatively assume other low energy positions. As the downstream flow of blood slows near the end of a pumping stroke, downstream displacement of the leaflets results in their prerotation toward the closed position orientation, all being controlled by the interengagement of flat ears, which extend laterally from opposite surfaces of the leaflets, and receiving cavities of unique design. The cavities include upstream and downstream lobes separated by an intermediate throat portion defined by inward and outward fulcrums.

Abstract: A method of making a prosthetic heart valve having an occluder which is supported to pivot between open and closed positions in an annular valve body made of pyrocarbon or a pyrocarbon-coated substrate. The valve body contains diametrically opposed pivot supports formed on the interior surface thereof and is distended by subjecting it to diametrically opposed compressive forces of a nature which place extensive exterior regions of the valve body in compression while increasing the distance between the pivot supports. After the occluder is installed in the distended annular valve body, removal of the opposed compressive forces permits the valve body to return to an unstressed, generally circular configuration with the occluder operatively secured between the pivot supports. These forces are applied using flexible, inextensible cables or resilient pressure pads.