| abstract |
An expansible assist pump for implantation through the femoral artery (left ventricle) or the femoral vein (right ventricle) is used as circulatory support in patents with severe cardiac shock. The pump comprises a body pump, or external chamber, having a double lumen wall, that is expansible and of variable rigidity, and a transvalvular segment, or flexible "neck" of the pump, that conforms itself to the situation or position of "open" or "closed" of the aortic or pulmonary valves and avoids the need of using a valve in the discharge of blood from the pump. An internal balloon having a progressive wall thickness is provided and causes a sequential rhythm of inflation and deflation. The pump further comprises a uni-directional nozzle system that functions as an admission valve, and a conducting catheter including two conduits, one for the pneumatic drive and activation of the balloon and the other for the injection of liquid or gas at high pressure into the double wall system of the body pump thus causing its expansion and variable rigidity. |