Electromagnetic and hydrodynamic characteristics of the extracorporeal magnetic driving system for an axial flow blood pump

Wei Tan - Jianping Tan - Yunlong Liu - Zhuo Tan

School of Mechanical and Electrical Engineering, Central South University, Changsha, 410083, China

Abstract
Extracorporeal magnetic driving approach is a potential alternative to replace conventional intra-driving methods for the axial flow blood pump, which can minimize external infection brought by through-skin wires and simplify the internal structure. The investigation has been undertaken to study electromagnetic and hydrodynamic characteristics of four novel large gap extracorporeal in magnetic driving systems varying in connection of structure, inclination angular and magnet pole number. Using finite element analysis based simulation and empirical verification, comparison upon performance of four different extracorporeal magnetic schemes was conducted. Using ANSYS, numerical solutions have been obtained consisting of vector plots of 3D magnetic field density and flux plots of 2D mean torque data. W-shape as a preferred scheme has 71.52 % and 148.32 % increments of the magnetic field density and mean torque on the axial flow blood pump, respectively, over D-T-shape. Experiment has verified the simulation results by direct measurement of magnetic field density, flow rate and pressure head, which has the magnetic field density and torque increased by 38.70 % and 145.56 %, respectively. Both simulation and experiment indicate that the addition of connection, inclination and magnet pole number would boost the performance; thus, the W-shape is the preferred system. Tables 5, Figs 11, Refs 21.