Assessment and improvement of the system efficiency for the moving-actuator type biventricular assist device

This is a test report on the efficiency of a moving-actuator type biventricular assist device (AnyHeart, Seoul National University). From the viewpoint of the various system mechanisms, the device can be subdivided into three separate parts: the motor and its associated controller, the actuator and motor assembly, and the blood sac and its associated components (including valves). The motor was operated under various conditions, including different torque, angular speed, and voltage pulses. The total system efficiency of 8% has been reported before, with subpart efficiencies of 50%, 85%, and 19%, respectively, for the motor and its associated controller, the actuator and motor assembly, and the blood sac and its associated components (including valves), under normal operating conditions (4 L/min pump output, 100 mm Hg aortic pressure [AoP]). This article focuses on the method of analyzing and improving the system efficiency. The applied input voltage under the normal operating conditions of the pump was determined using the analyzed results. Also, a speed profile that takes into consideration the filling state of the blood sac was provided. On the basis of tests performed involving in vitro mock circulation, experimental results are provided to demonstrate the effectiveness of the approach presented in this article.