Vascular Engineering of Circulatory Assist Devices

Abstract

Heart failure is a condition in which the heart cannot pump sufficiently because its contractile force has deteriorated. Patients with heart failure can sometimes undergo heart transplantation, but in number these patients comprise less than 10 % of patients actually requiring heart transplantation. Thus, mechanical circulatory assistance plays an important role in substituting for heart transplantation wherein the pump function of the heart is assisted by an artificial blood pump called a ventricular assist device. On the other hand, cardiopulmonary bypass is a form of extracorporeal circulation that temporarily takes over the function of the heart and lungs to maintain the circulation of blood and the oxygen content of the body during surgery for heart failure and aneurysms of the thoracic aorta. This chapter describes the vascular engineering of circulatory assist devices. Particular emphasis is placed on recent progress in ventricular assist devices and cardiopulmonary bypass pumps. These important medical devices assist with human circulation at either the chronic or the acute phase. Because these devices are derived from an industrial pump, a great many studies have been conducted not only from the medical perspective but also from industrial and engineering perspectives. In this chapter, current ventricular assist devices and cardiopulmonary bypass pumps, their specifications, their classifications, and methods for their design and evaluating are presented, including flow analysis inside the pump to optimize the geometry.