SINGLE SAC VENTRICULAR ASSIST DEVICE

摘要

A ventricular assist device (VAD) for assisting either or both heart ventricles. The VAD pumps blood between an inlet and an outlet. The VAD includes a bearingless electromagnetic drive unit comprising an armature disposed between two cores, a compressible sac, valves, and a frame. The armature moves toward the sac in an eject stroke for expelling blood therefrom to the outlet. An energy storage element is preferably included and adapted to store and release energy from the drive unit. The armature is decoupled from the compressible chamber after completion of the eject stroke such that the armature retracts. Following retraction, the sac is passively filled with blood from the inlet and the energy stored in the storage element during retraction is delivered during the eject stroke. The device preferably has two cores with coils wound around each core's center section or legs. Alternatively, one of the cores is coil-less.