Modeling and simulations of a novel magnetorheological peristalsis blood pump

Although heart disease is still the major cause of death in the world, cardiovascular mortality rate has decreased over the past years, which is mainly related to invention of different types of circulatory assist devices. Therefore, focus of recent studies lies at developing the cardiovascular assist technologies to further decrease mortality rate. Currently, impeller-driven and centrifugal pumping technologies are the state of art for artificial heart applications. These types of pumps are able to lengthen lives, however their operation produces blood damage(hemolysis) which makes them not suitable for long-term applications. A natural solution to the need to artificially pump blood over long time frames while accruing less blood damage can be found in peristaltic pumps. The peristaltic pump design discussed herein mimics the heart's natural operation by using magneto-active elastomers that respond to the presence of external electromagnetic fields. Utilization of a magnetorheological (MR) elastomer rather than rotating rollers could constitute a materials-based solution for solving the mechanical issue of hemolysis by avoiding impellers. Additionally, the mechanism produces desirable pulsatile flow. In this work, a magnetically driven peristalsis pumping mechanism is proposed and simulated using fully coupled finite element simulations in COMSOL Multiphysics. The primary goal of this work is to develop high(er) fidelity simulation of the working peristaltic pump in order to determine how design factors and the pumping mechanism affects hemolysis. Power law damage metrics, beyond basic flow shear stresses, were used to compare the hemolysis index in the proposed model with the results from previous works. Results show that blood damage at higher magnetic fields strength was larger than weaker applied magnetic field. Regardless of the magnetic field strength, average blood damage was higher approaching the outlet versus the inlet. In addition, this study shows the efficacy of the device geometry and means of operation which can be intermediate optima pointing toward possible optimization of peristaltic pump to increase the efficacy of the pump.