Prototype of Miniaturized Magnetically Levitated Motor for Paediatric VAD

Abstract

A miniaturized magnetically levitated motor which can actively control 5-degrees of freedom (5-DOF) of impeller postures has been newly developed for a paediatric ventricular assist device (VAD). Developed motor consists of a top stator, a bottom stator and a levitated impeller that is set between the both stators. The diameter and the height of the motor are 28 mm and 41 mm, respectively. Magnetic field analysis with finite element method was performed in order to design the geometry of motor permanent magnets and a stator. Corners of the motor permanent magnets were cut to produce sinusoidal distribution of magnetic flux density and to reduce the cogging torque. The developed maglev motor produces sufficient suspension force and rotates the levitated impeller up to a rotating speed of 6000 rpm with sufficient posture control performance.