Control systems for the electric heart.

Methods to predict and control cardiac output (CO) accurately in total artificial heart (TAH) recipients have varied significantly in the last few decades. Early models exhibited minimal control mechanisms and involved fixed pumping parameters. Elaborate electromechanical systems that have recently evolved require intricate communication between the circulating blood volume and the electric pump to maintain blood flow to critical organs. Attempts to quantitate specific end-organ blood flow, metabolic alterations, and oxygen delivery and, finally, to link these functions to the control of the TAH have not succeeded. Current devices seek to predict the needed CO by monitoring preload, afterload, or a combination of both. No consensus has developed concerning the appropriate physiologic parameters that should be surveyed in vivo and then used to regulate the output of the TAH.