Passive aortic counterpulsation: Biomechanical rationale and bench validation

Aortic counterpulsation (IABP) consists in an ECG-controlled forced deflation and inflation of a balloon positioned in the aorta. The device is designed to decrease the ventricular afterload during systole and to increase the coronary driving pressure during diastole. In biomechanical terms, the IABP improves the mechanical matching between the pump and the load, facilitating the transfer of ventricular energy. This paper describes a completely passive aortic counterpulsation solution, with an intra-aortic balloon without a pumping system, designed to improve the mechanical matching between the ventricle and the artery at very low cost and complexity. The only requirement is an external reservoir to amplify the balloon pulsations due to physiologic arterial pressure pulse.