Abstract
The characterestics of the circulatory autoregulation during artificial heart pumping were studied, employing a simple mathematical model of the pulmonary and systemic circulation and the artificial heart. The unstable physiological state of arterial and venous pressure caused by the decreased cardiac output sensitivity to the venous pressure and the elevation of the pulmonary venous pressure more than 10 mmHg caused by the of terload effects, i.e., the decreases in cardiac output with increased arterial pressure, were predicted by numerical computations under the case of left, right or total artificial heart replacement. To improve the characterestics of the circulatory autoregulation, the servo-mechanism control and driving system of the total artificial heart was designed. In this system, cardiac output was regulated by the automatic changes in the driving pressure corresponding to the changes in the venous pressure, so that the venous pressure could be maintained at any constant level or within any desired range during the pumping.
