Numerical simulation of centrifugal and hemodynamically levitated LVAD for performance improvement

Left ventricular assist device (LVAD) provides an effective artificial support system to the heart patients. Despite the improved life survival rate, complications like hemolysis, blood trauma, and thrombus formation still limit the performance of the blood pump. The geometrical aspects of blood pumps majorly influence the hemodynamics, therefore these devices must be carefully engineered. In this work, several versions of centrifugal blood pumps are simulated using ANSYS-CFX to propose a best compatible design for LVAD. A hemodynamic levitation approach for the impeller is also suggested to overcome the cost and weight issue associated with the magnetic levitation. The blood flow is modeled by implementing Bird-Carreau model and its turbulence is solved using the SST turbulence model. The influence of the blade profile, blade tip width, blade numbers, and splitter blades on the hemodynamic characteristics through the pump is observed. An optimum design of centrifugal blood pump for the assistance of failed ventricle is proposed that can effectively pump the blood from the left ventricle to the ascending aorta. The proposal can be adopted by LVAD designers to have hemodynamically tuned efficient product.