Abstract
One of the causes of the valve failures of the artificial heart was the high pressure gradient which appeared across the valve at the moment of valve closing by water hammer phenomenon. In order to decrease the pressure gradient across the valve, the shock absorbent material was used in the valve holding ring, then the pressure gradient was measured by using Mock circulation. An experimental model was developed, in which the shock absorbent material was used in the valve holding ring. The pressure gradients were compared among the control without any shock absorbent material (the valve was mounted in a rigid ring), Silicone, and the special shock absorbent material. The pressure gradient across the valve increased along with the increase of the % systole of the driving of the artificial heart. Maximum pressure gradient was measured at the moment of valve closing just after the valve opened completely. The maximum pressure gradient across the valve by the water hammer phenomenon was highest in the control, lowest in the model in which the special shock absorbent material was used in the valve holding ring. It became obvious that the special shock absorbent material was effective to decrease the pressure gradient across the valve by the water hammer phenomenon.
