Dynamic suspension performance of an ultra compact 5 DOF controlled axial gap type self bearing motor for use in pediatric ventricular assist devices

Research interest in miniaturization of magnetically suspended motor is increased to develop next generation ventricular assist devices (VADs) for pediatric heart disease treatment. In this study, an ultra-compact 5-degrees of freedom (DOF) controlled axial gap type self-bearing motor which employ double stator mechanism has been proposed. A six-slot and four-pole self-bearing motor which has 22 mm in diameter and 34 mm in height, and centrifugal pump was fabricated. This paper investigated pump characteristics, and then dynamic impeller suspension performance with frequency response evaluation. The developed maglev pump for pediatric VAD demonstrated non-contact pump drive producing flow rate of 0.5-3.0 L/min against head pressure of around 100 mmHg at rotating speed of 4000-5000 rpm. In addition, the maglev motor indicated sufficient bandwidth for impeller suspension control during pump drive.