Pressure-Flow Relationship and Dynamic Behaviour of Prosthetic Heart Valves

摘要

The present study demonstrated a hydrodynamic analysis of prosthetic heart valves by correlating the aortic flow, mitral flow, the pressure drop across the aortic and mitral prosthetic valves, and the flow induced motions of the prostheses. The temporal variations of the aortic and mitral flows were simulated in a pulse duplicator via a bellows pump and a cam. The shape of the cam was designed to generate a physiological ventricular volume curve. The dynamic interaction between aortic and mitral prostheses were seen from the variations in mitral and aortic regurgitation when different pairs of valves were used. For the same cam, an increase in pulse rate would lead to a proportional increase in the instantaneous Reynolds number should the alteration in regurgitation be negligible. Because of larger energy loss associated with higher Reynolds numbers flows, the mean discharge coefficient for a Starr-Edwards aortic valve, during the forward flow with positive pressure drop, decreases with the pulse rate.