Baxter International Inc.

Ronald A Ness

Herbert Chen

John C Woodard

Than Nguyen

Richard M Romley

A ventricular assist device includes a pair of valved conduits and a pumping portion connected by these conduits into the circulatory system of a host patient. The pumping portion and valved conduits are constructed and configured to minimize the number of material-surface transitions which blood must cross in flowing through the device. Also, the valved conduits include porcine xenograft valves, which are externally supported by stenting structure located outside of the blood-contacting flow path of the device. A flexible shape-retaining inner wall member of the valved conduits is impervious to blood, but defines a porous inner surface on which a stable biological interface may form. Also, this inner wall member is shaped with sinuses which do not replicate either the porcine sinuses from which the xenograft valves were taken, or human aortic sinuses. However, the sinuses of the inner wall member are configured to provide effective valve action by the formation of vigorous vortices in the blood flow downstream of these valves, and to avoid the formation of clots on the blood-contacting surfaces of the valved conduits.

Ventricular assist device with minimal blood contacting surfaces

Ventricular assist conduit with externally supported tissue valve

A pump system is described which is particularly suited for use as a left ventricular assist device for internal use in humans. The pump system generally includes a pump having a deformable sac formed in a seamless piece of flexible resilient material having (i) a pair of opposite substantially planar walls and of substantially circular shape joined by an annular wall of substantially semicircular cross-section and (ii) inlet and outlet means. The inlet means have an asymmetric tapered section positioned to direct the inlet flow toward the annular wall of the sac to produce a smooth circular flow within the sac and minimize thrombus formation. A pair of pusher plates are disposed on opposite sides of the sac. Each of the pusher plates are engageable with a respective one of the planar walls of the sac for displacing at least one of the planar walls toward the other to deform the sac. The pump system also includes removable inlet and outlet conduit means with valve means for controlling inlet and outlet flow. Each of the conduit means include connecting means having sealing means for securing the inlet and outlet conduit means to the pump.

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Castro Valley, CA, United States of America

Ronald A Ness