2019 年 27 巻 2 号 p. 219-225
A compact maglev motor has been developed for pediatric ventricular assist devices (VADs). The maglev motor consists of a top stator, a bottom stator and a levitated impeller which is suspended with 5-degrees of freedom control. The maglev motor has an outer diameter of 22 mm and a total length of 33.6 mm. The maglev motor has been improved by magnetic circuit refinement to enhance magnetic suspension characteristics and reduce power consumption. In this study magnetic suspension performance of the improved maglev motor during pumping was evaluated. The developed maglev pediatric VAD indicated sufficient pump performance to regulate a flow rate of 0.5-2.4 L/min against a pump head pressure of 100 mmHg at a rotating speed of 4000-5000 rpm. The maximum oscillation amplitudes were successfully suppressed less than 0.05 mm in axial direction and 0.16 mm in radial direction. The results indicated that the improvement of the motor significantly contributes to enhance the magnetic suspension and rotation performance.
