We have studied the performance of commercially available prosthetic heart valves seven mechanical valves and six biological valves) by the use of our in-vitro test apparatus. Following the steady flow study, hemodynamic performance of prostheses were compared. Our pulse duplicator system consists of a pneumatic driven pulsatile pump, natural rubber tubes, compliance regulating tanks and needle valves. Various types of valves can be inserted in the pump inlet and outlet. At the aortic position output and pressure gradient were found to be similar in all valves except for the ball valve. At the mitral position, however, pressure gradient showed difference among the valves; the gradient across porcine xenografts and ball valve were higher than those across disc valves and bovine pericardial xenografts.
