Abstract: A ventricular-assist-device valve includes two flaps hinged to a peripheral wall by means of a couple of flexible struts. As each flap opens and closes during each cycle of operation, the struts flex and open passages for flow around them, around the flaps, and between the struts and the flaps, so as to prevent the formation of dead zones that contribute to the accumulation and deterioration of blood cells that produce clotting. The struts are tensioned so as to exert a pressure against the flow of the blood stream when the flaps are open. This tension creates a pressure differential between the underside and the peripheral regions of the flaps that forces blood flow around the hinges and washes out stagnant cells. As a result, clotting is materially reduced.

Abstract: A pneumatic pump comprises two coaxial cylindrical pumping chambers, each enclosing a piston connected to the other through a partition by a tube, thereby forming a monolithic piston assembly that is driven axially by a common electrical actuator providing reciprocating motion. The volume in the bottom chamber is selected as needed to provide the desired pressure in the left ventricle of an artificial heart driven by the pump. The diameter of the tube connecting the pistons is selected such that the stroke volume of the top chamber is reduced with respect to that of the bottom chamber as needed to match the reduced pressure requirements of the right ventricle of the artificial heart. Check valves are used in each chamber to ensure venting of excess pressure during the blood ejection phase and to limit the vacuum during the fill phase.

Abstract: A pneumatic pump comprises two coaxial cylindrical pumping chambers, each enclosing a piston connected to the other through a partition by a tube, thereby forming a monolithic piston assembly that is driven axially by a common electrical actuator providing reciprocating motion. The volume in the bottom chamber is selected as needed to provide the desired pressure in the left ventricle of an artificial heart driven by the pump. The diameter of the tube connecting the pistons is selected such that the stroke volume of the top chamber is reduced with respect to that of the bottom chamber as needed to match the reduced pressure requirements of the right ventricle of the artificial heart. Check valves are used in each chamber to ensure venting of excess pressure during the blood ejection phase and to limit the vacuum during the fill phase.

Abstract: A primary scotch yoke and a secondary scotch yoke are coupled in opposing arrangement and rigidly attached to a linearly reciprocating element. Each scotch yoke includes a rotary actuator with a cam follower and a yoke attached to the reciprocating element. Each yoke has a cam with an open gap through which the follower may be disengaged from the cam and stopped to an idle position. The follower of the secondary scotch yoke is kept idle in a position similarly disengaged from its cam. A controller detects a failure in the primary scotch yoke, disengages the cam follower of the primary yoke from its cam, and energizes the secondary scotch yoke, thereby causing its cam follower to engage its yoke and continue to provide uninterrupted motion to the reciprocating element, in particular the portable pneumatic pump driving an artificial heart.

Abstract: Apparatus and method for inserting a stent graft limb branch into a stent graft body disposed in a living being, the stent graft body having a trunk and an opening for receiving said branch. A guide element is inserted through a vessel of the living being to the vicinity of the branch receiving opening of the stent graft body. The guide element is manipulated in three dimensions to form a shape corresponding to the orientation of the branch receiving opening with respect to the position of the vessel, so that the guide element shape is varied, in situ, to the required shape despite any abnormalities in the shape and orientation of the vessel. The guide element, after formation into the proper shape, is inserted into the branch receiving opening of the stent graft body. The stent graft limb branch is then fed over the guide element until the distal end of the limb branch is received in the branch receiving opening of the stent graft body. The guide element itself is also novel.

Abstract: A driver is disclosed for powering a pneumatically operated implantable device, such as an artificial heart with a left and a right ventricle. The driver includes a pair of compressors that each has a first and a second compression chamber. In a first mode of operation, both the first and the second compressor power the left and right ventricle of the artificial heart. In the event of a malfunction in the second compressor, the left and right ventricles of the artificial heart may be powered by the first compressor. Similarly, if a malfunction occurs in the first compressor, the artificial heart may be fully powered by the second compressor.

Abstract: A driver is disclosed for powering a pneumatically operated implantable device, such as an artificial heart with a left and a right ventricle. The driver includes a pair of compressors that each has a first and a second compression chamber. In a first mode of operation, both the first and the second compressor power the left and right ventricle of the artificial heart. In the event of a malfunction in the second compressor, the left and right ventricles of the artificial heart may be powered by the first compressor. Similarly, if a malfunction occurs in the first compressor, the artificial heart may be fully powered by the second compressor.