Baxter International Inc.

Novacor Medical Corporation

Andros Incorporated

Herbert Chen

Ronald A Ness

John C Woodard

Jal S Jassawalla

Than Nguyen

Richard M Romley

Donald T Shannon

Michael G Conley

Ingvar Olaffson

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

A smooth-walled non-crimped inflow conduit for an implantable ventricular assist system. The conduit has an internally smooth lumen surface for enhanced washing of the conduit under irregular blood flow conditions. The conduit includes a tubular graft body that may be formed of a knitted fabric sealed with bovine collagen or gelatin, or formed of closed structured PTFE. The conduit may include external ribbing or support to prevent inward collapse under negative pressure conditions and also protect against damage from inadvertent physical contact in the operating room. The external support may be bonded to the exterior or formed integrally with the tubular graft body. An outer reinforcement cage may be provided to help prevent gross distortion or damage to the tubular graft body. The ends of the tubular graft body are left unsupported and wrapped around opposed lips of conduit coupling structure to minimize blood contacting surfaces at junctions with other conduits or with the heart. The conduit may be provided in an implantable left ventricular assist system also including a pumping device, valved conduits, and a power supply.

Smooth ventricular assist device conduit

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.

Blood pump system

An improved implantable infusion device for delivering precisely regulated doses of fluid into the body of a patient is disclosed. The device utilizes a resilient non-compliant pump bellows that is directly coupled by a gear train to a motor. The bellows is biased toward the expanded position and this factor, combined with the mechanical inertia of the gear train, substantially eliminates the danger of an overdose of infusate being released into the patient.

Implantable infusion device

A chamber structure in a blood pump or the like is described. The structure includes a deformable sac having an annular side wall which is held in a rigid condition, and a pair of opposed circular walls, each joined to the annular side wall through a flexible annular wall portion. A circular pusher plate acting against each circular wall has an initial deflection position at which the associated flexible wall portion in the sac takes the form of a circumferentially uniform roll having an outwardly convex, bulged cross sectional curvature. The rolls in the sac maintain their circumferentially uniform, bulge-like character as the pusher plates are moved toward inwardly moved positions.

Implantable pump

A cassette is described for use in an intravenous delivery system having a pump. The volume of a main chamber defined by the cassette body is varied by a membrane in a wall thereof while unidirectional inlet and outlet valves maintain the direction of fluid flow into and out of the main chamber. A prechamber is positioned above the inlet port in order to accumulate air from the upstream portion of the intravenous delivery system in which the cassette is used.

Growing community of inventors

Kensington, CA, United States of America

Herbert Chen