A ventricular assist device designed by use of Computational Fluid Dynamics

Abstract

Aims: the purpose of this study was to develop a new left ventricular assist device which causes less blood damage. Methods: During design of the device, the method of Computational Fluid Dynamics (CFD) was used to optimize the device shape, number of impeller vanes, the structure and position of the guide vanes, and the size of the impeller screw-pitch. After that the device, that was an axial flow blood pump, was produced without an absolute brushless DC motor and was constructed with a housing, an impeller with two blades, three guide vanes, ceramic bearings, and an inlet and outlet. We measured the dynamic and hemolysis performances and the surface temperature in an in vitro experiment. We also detected the trauma inflicted by this pump on the blood by testing to failure on a goat heart. Results: the experimental tests indicated that the dynamic performance of the axial flow pump included a nearly 6 L/min flow rate against a pressure of 100 mmHg with rotation at 10000 rpm, that output could satisfy demand during use as a left ventricular assistant device (LVAD). The normalized index of hemolysis (NIH) values from in vitro and in vivo experiments were 0.047±0.017 mg/ 100 mL and 0.016±0.011mg/100 mL, respectively. The results showed that the blood pump designed using CFD showed far less damage to blood than the previous pumps and also showed improved durability as tested in vivo in animals.