VENTRICULAR ASSIST DEVICE COMPRISING ENCLOSED-IMPELLER AXIAL FLOW BLOOD PUMP

摘要

The present invention relates to a Ventricular Assist Device (VAD) comprising an axial flow blood pump which can be used as bridge to heart transplantation and as a permanent implant. The pump of the present invention is of an enclosed-impeller axial flow design, in which the rotor comprises impeller blades that intersect at an axis of rotation to form a hub of a relatively small size. The minimization of the hub volume allows a larger internal volume of the rotor to be occupied by the fluid. The pump can also be viewed as a double casing axial flow blood pump in which the permanent magnets required for the DC motor can be embedded in the enclosing tube (rotor) and the motor windings can be enclosed in the pump casing (stator). The configuration thereby optimizes the electrical coupling and this minimizes power requirement. In a preferred embodiment, the axial flow blood pump of the present invention is implantable in the ventricle of a patient. In such an intra-ventricular VAD, although the pump has a continuous speed, the pump output is pulsatile when inserted in the native heart.