A numerical model applied to the simulation of cardiovascular hemodynamics and operating condition of continuous-flow left ventricular assist device.

The mathematical modeling of the cardiovascular system is a simple and noninvasive method to comprehend hemodynamics and the operating mechanism of the mechanical circulatory assist device. In this study, a numerical model was developed to simulate hemodynamics under different conditions and to evaluate the operating condition of continuous-flow left ventricular assist device (LVAD). The numerical model consisted of a cardiovascular lumped parameter (CLP) model, a baroreflex model, and an LVAD model. The CLP model was established to simulate the human cardiovascular system including the left heart, right heart, systemic circulation, and pulmonary circulation. The baroreflex model was used to regulate left and right ventricular end-systolic elastances, systemic vascular resistance, and heart rate. The centrifugal pump HeartMate III used as an example to simulate the rotary pump dynamics at different operating speeds. Simulation results show that hemodynamics under normal, left ventricular failure and different levels of pump support conditions can be reproduced by the numerical model. Based on simulation results, HeartMate III operating speed can be maintained between 3600 rpm and 4400 rpm to avoid pump regurgitation and ventricular suction. Additionally, in the simulation system, the HeartMate III operating speed should be between 3600 rpm and 3800 rpm to provide optimal physiological perfusion. Thus, the developed numerical model is a feasible solution to simulate hemodynamics and evaluate the operating condition of continuous-flow LVAD.