MODIFIED CIRCULATORY ASSIST DEVICE

摘要

This invention is a circulatory assist device having a housing (16) and a pumping membrane (14), with a control chamber (26) and a pumping chamber (28). The device is mounted on a catheter and collapsed to a sufficiently small diameter to allow insertion into the vascular system of a patient. An expansion mechanism (20) in the device, such as a stent, can be expanded to hold the housing in an expanded, substantially rigid state, while control fluid is pumped into and evacuated from the control chamber to repeatedly deflect the pumping membrane. At least one opening (22) is formed in the device, to allow vascular fluid to enter and exit the pumping chamber as the pumping membrane deflects. Introduction and evacuation of control fluid can be synchronized with the heart cycle of the patient. After use, the housing is contracted to a smaller diameter to allow withdrawal from the vascular system.