抄録
Physiological and dynamic investigations were carried out to compare the parformances of natural and artificial heart as a blood pump from the preload and afterload effects on cardiac output. Pumping capacities for the circulation were analysed using the new designed flow limit type pressure regulator and the atrial pressure damper to control the load pressures of the ventricle and the artificial heart at desired levels.
The results of this analysis showed that at low contractile state of the ventricle the afterload effects, i. e., the decreases in cardiac output with increased arterial pressure, were much greater than those at normal or high contractile states within the physiological range of the atrial pressure. The output flow rate of the artificial heart also decreased with increasing the of terload pressures, but the most important result obtained from the experiments was that increased pump suction and driving pressure of the pump, increased modulus of elasticity of the ventricular wall material and increased inflow valve resistance caused a depressive effect on the cardiac output sensitivity of the artificial heart to venous pressure changes.
From these results the intrinsic regulation mechanism of the artificial heart was discussed from the points of the end systolic and diasotlic volume control.
