Abstract: A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade.

Abstract: A totally or partially implantable fluid delivery system actuated by a valveless piezoelectric drive system. The drive system may actuate an artificial heart by a hydraulic bladder or directly actuate a human heart. The drive system has an output with a frequency and displacement sufficient to directly drive a human or artificial heart and includes a control circuit for recapturing and reusing the power driving the piezoelectric drive system. An artificial heart which includes two check valves having a flexible valve element and supporting tabs on opposite sides.