Optimization And Blood Damage Prediction Of A Micro Ventricular Assist Device

Ventricular assist devices provide long- and short-term support to heart failure disease patients; these devices are desired to match the remarkable functionality of the natural heart, which makes their design a very time consuming and challenging task. This thesis focuses on performing blood damage prediction and optimization for a novel transapical to aorta axial blood pump by means of computational fluid dynamics simulations.This thesis at first introduces the development history and current state of ventricular assist devices and presents the working principles and expected outcomes of a novel transapical to aorta axial blood pump, computational fluid dynamics simulation techniques and mechanism of blood damage caused by blood pump. Then three blood pump models with different impeller blade heights (BH150, BH200, BH250) were proposed, pump characteristics and inner flow patterns including velocity distributions, static pressure distributions, path lines distributions and shear stress distributions were analyzed using computational fluid dynamics simulation method.According to the results, model BH150 has the best hemo-compatibility, but can't provide a sufficient outflow rate for human circulation. Model BH250 has the highest outflow rate but also the most severe blood damage possibility among all three models. Model BH200 can provide a sufficient outflow rate exceeding 5 L/min under the rotation speed of 20,000 rpm and pressure difference of 100 mm Hg. Additionally, it has a very low possibility to cause blood damage during operation. The flow pattern in model BH200 is smooth and reasonable, totally achieve the expectation of the design.