Development of a centrifugal blood pump for ECMO and VAD operations

Abstract

Using cardiopulmonary circulatory assist devices has been increased in the recent years as more models are available in the market. These devices can be employed in the situation during which both cardiac and respiratory support to a patient's heart and lungs have to be provided, either during or after surgeries, for short time or even in the case of severe disease, for a period of weeks. Hence, it is critical to know the details of the phenomena happen inside a blood pump from both mechanical performances (such as pressure head and mechanical efficiency) and biomedical factors (such as hemolysis and thrombosis) and to design an optimum pump from both aspects. This paper investigates development of centrifugal blood pump impeller, specifically with focusing on the performances during ECMO condition. The baseline model is designed by investigating existing commercial pumps and considering results of recirculation, pressure heads and mechanical efficiencies together with their biomechanical performance via Modified Indices of Hemolysis (MIH). Afterword, two more modified models are designed and simulated. Overall, a comprehensive comparison between the results of all three case demonstrate that when impeller radius and prime volume is smaller, recirculation is reduced at impeller and MIH value becomes lower. Additionally, high scalar shear stress is observed near the volute and impeller walls and inside the top cavity gap.