Control aspects of intraaortic balloon pumping: an overview

Temporary or permanent, internal or external, in-series or bypass cardiac assist devices are examined with emphasis on intraaortic balloon pumping. Physiological and clinical consequences of the medical assistance are discussed. Major advantages of the devices are to provide adequate perfusion and, secondarily, to unload the heart and to reduce oxygen consumption of the failing myocardium. Major problems with the cardiac assist devices are related to synchronization with the natural heart, or proper timing, and to the determination of suitable control variables. Optimization algorithms based on the selected performance criteria and computer-based automatic controls are instituted to overcome some of these shortcomings. Finally schemes of automatic control of implantable assist devices are discussed