Engineering analysis of an atrial contraction on mitral valve performance in a new mock circulatory system

In order to clarify the effect of atrial contraction on the hydrodynamics at mitral valve, a new-type mock circulatory system has been developed. In this system, an artificial atrium can be slightly collapsed prior to the contraction of the ventricle. After the modification of the software of the pneumatically-operated heart driver, both atrium and ventricle could be synchronously driven under different drive timings for the two chambers. An extraordinarily high pressure peak, which is known as the waterhammer phenomenon, is generally measured in the vicinity of the valve. However, the waterhammer level could be reduced by 40% when the atrium was actively driven for 50msec prior to the contraction of the ventricle. The results through this experiment suggested that the drive timing for two chambers indicated a great factor on the valve closure, and they also exhibited that the prosthetic valve performance were able to be evaluated by using this newly- developed mock circulatory system under physiologic conditions.