LONG-TERM CENTRIFUGAL VENTRICULAR ASSIST DEVICE

CENTRIFUGAL BLOOD PUMPS HAVE BEEN USED EXTENSIVELY FOR SHORT-TERM CIRCULATORY ASSISTANCE AND PERFUSION PUMPS. THEIR UTILITY FOR LONG-TERM VENTRICULAR ASSISTANCE IS LIMITED BY THROMBUS FORMATION AT THE SHAFT SEAL. ABIOMED, INC., WILL DEVELOP A MAGNETICALLY SUSPENDED CENTRIFUGAL BLOOD PUMP THAT WILL HAVE NO SHAFT SEAL AND BE SUITABLE FOR LONG-TERM CIRCULATORY SUPPORT IN EITHER AN IMPLANTED OR EXTRACORPOREAL CONFIGURATION. AN ATTRACTION-TYPE MAGNETIC BEARING WITH A RADIALLY PASSIVE,AXIALLY ACTIVE GEOMETRY WILL BE UTILIZED. THERE WILL BE A SIMPLE FLUID FLOW PATH AROUND A TOROIDAL ROTOR, WHICH IS THE ONLY MOVING SOLID ELEMENT. THE RESULTING PUMP CAN BE SMALL, LIGHT, SIMPLE, AND VERY RELIABLE, WHILE NOT BEING LIMITED TO SHORT-TERM USE BY THE SHAFT SEAL OF PRESENTLY USED CENTRIFUGAL INFUSION PUMPS. THIS DEVICE WILL BE MORE COMPACT AND INHERENTLY SIMPLER THANVALVED PULSATILE VENTRICULAR ASSIST DEVICES. WITH ONLY ONE MOVING PART, NEEDING NO DEFORMABLE MEMBRANES OR MULTIPLE VALVES, AND CAPABLE OF OPERATING IN EITHER PULSATILE OR NONPULSATILE MODES, SUCH A PUMP WITH LOW HEMOLYSIS AND THROMBOGENESIS LEVELS WILL BE AN EXTREMELY RELIABLE AND WIDELY APPLICABLE FORM OF CARDIAC SUPPORT.