Centrifugal pediatric ventricular assist device with 5-DOF controlled self-bearing motor

Abstract

　Mechanical circulatory support is one of the strongest candidate for heart disiese treatment. Research interest in pediatric circulatory support using ventricular assist devices (VADs) increases due to the succsessful use of VADs in adult heart failure therapy. In this study, a next generation continuous flow maglev VAD with a 5-degrees of freedom (5-DOF) controlled axial gap type self-bearing motor has been developed for pediatric circulatory support. The developed pediatric VAD prototype, which consists of a top stator, a bottom stator, a centrifugal blood pump and a levitated rotor impeller, has 31 mm in external diameter and 36 mm in hight. This paper investigated the disturbance force acting on the levitated impeller and the magnetic levitation stability in several driving condition of the centrifugal pump. The distrurbance force was estimated by using static suspension force and torque characteristics of the 5-DOF controlled self-bearing motor. The developed pediatric VAD suppressed the disturbance force and indicated non-contact levitation up to a rotating speed of 5000 rpm.