2018 Volume 26 Issue 1 Pages 102-108
We have developed a small, thin, maglev ventricular assist device for mild heart disease patients. A radial type self-bearing motor are adopted to reduce the axial thickness of the device. The first prototype self-bearing motor had a narrow control range of 0.2 mm, and the maximum oscillation amplitude was also large. Improvement of self-bearing motor was carried out. The improved self-bearing motor has been expanded its outer diameter from Φ 30 mm to Φ 35 mm, and widened the air gap from 0.8 mm to 1.3 mm. In this paper, radial atractive force and levitation characteristics in the air of the levitated impeller of the improved selfbearing motor were assessed. The radial control range increased to 0.4 mm. The radial maximum oscillation amplitude decreased by 60%.
