NUMERICAL STUDY FOR FLOW IN PHOENIX LEFT VENTRICULAR ASSIST DEVICE AT PEAK SYSTOLE

Abstract

The Phoenix left ventricular assist device is driven by pneumatic pump outside a human body to provide air flow in-and-out of a pneumatic diaphragm inside the blood chamber. The inflation and deflation of the diaphragm drives the blood flows. At peak systole, blood flows into aorta with a maximum flow rate both from natural ventricle and artificial ventricle. To assess the critical condition, blood flow pattern of the device at peak systole is studied. We apply the finite volume method with ϰ – ε turbulent model to simulate the steady flow at peak systole. Results provide a comprehension of fluid dynamic effect not only the region inside the ventricle but also that in the vicinity of the inflow channel and outflow valves of flow field. The numerical results show that maximum velocities were smaller within the ventricular chamber with bi-leaflet outflow valve than with tilting disk outflow valve. Analysis of the numerical solutions suggests that geometry similar to the bi-leaflet outflow valve results in a better flow dynamics within the ventricle chamber compared to a tilting disk valve.