A mechanical pulse duplicator for testing prosthetic mitral and aortic valves.

The purpose of a prosthetic cardiac valve is to restore the function of a diseased aortic or mitral valve, and its role in haemodynamics is a passive one: the opening and closing of such a valve is strictly regulated by the pressure differences in the cardiac chambers which communicate through this valve. Therefore we consider that a prosthetic valve should be tested under conditions simulating normal cardiac dynamics. We have designed and constructed a mechanical pulse duplicator with which it is possible to test artificial mitral and aortic valves, even simultaneously if so desired. Davila, Trout, Sunner, and Glover (1956) described a pulse duplicator which had a controlled systolic-diastolic ratio, stroke volume, and cardiac rate. The apparatus described below (Fig. 1) is much simpler, smaller, and less expensive. An advantage, compared with other similar devices, is that one can adjust the systolicdiastolic range and the shape of the ventricular, atrial, and aortic pressure curves exactly as one wishes.