US Patent 7172551 Cyclical pressure coronary assist pump

An intravascular pump, which may be a left ventricle assist device, comprising a wall defining a pumping chamber, the wall support by struts, the struts attached to or part of an actuation system to move the wall from an expanded position to a contracted position and back to operated the pump, the actuation system may be electrically activated shape memory alloy struts, electroactive polymeric struts, or may be a balloon, struts attached to a slidable member or other suitable system.