Patent ID: 8066628

Claim:
A ventricular assist device, comprising: an intra-aortic balloon pump sized and shaped to dangle inside a patient's aorta, the pump having a wall made at least in part from a moisture-resistant material; a skin interface; an external driver comprising a rigid bellows, a prime mover actuating the bellows, and valves arranged to permit multiple pumping modes, the prime mover being operably connected to a power source; an internal drive line connecting the balloon pump to the skin interface; an arterial interface, sized and shaped to pass the internal drive line through an arterial wall; an external drive line connecting the skin interface to the external driver; and a controller configured to receive (a) a blood pressure signal representative of at least a sensed blood pressure, and (b) an electrocardiogram signal; wherein: the balloon pump, the internal drive line, the skin interface, the external drive line, and the driver form a fluid system for containing pumping air to act as a pumping medium; and the controller is programmed to: operate the valves and the prime mover such that the pumping air is not pressurized more than a predetermined amount above a sensed blood pressure; cause the valves to adopt a closed pumping mode in which no air is added to or vented from the fluid system; cause the external driver to pump through multiple consecutive inflation-deflation cycles during the closed mode; cause the valves to adopt an open mode in which contraction of the bellows by the prime mover causes air in the fluid system to be vented from the fluid system and expansion of the bellows by the prime mover causes ambient air to be drawn into the fluid system, thereby charging the fluid system with new pumping air to act as the pumping medium; detect a QRS complex based on an electrocardiogram signal received by the controller; detect a dicrotic notch based on a blood pressure signal received by the controller; and trigger the driver to deflate the pump following the QRS complex and inflate the pump following the dicrotic notch.