2016 年 24 巻 3 号 p. 216-221
A new novel blood pump with a maglev impeller has been developed to recover cardiac functions. The pump's rotational speed is modulated based on synchronizing with the heart beat in order to increase the coronary flow to recover the patient heart. Levitation stability of radial axes of the pump operated in constant speed mode and pulsatile mode was evaluated with a mock circuit filled with water when the pump is set horizontally and/or vertically. Levitated impeller is contacted with pump casing in the pulsatile mode when the pump is set vertically. Radial fluid force of levitated impeller is estimated by computational fluid dynamics analysis when levitation impeller is displaced 0.0 mm and 0.4 mm toward radial axis. Radial fluid force with an impeller displacement of 0.4 mm is 2.8 N and it is three times greater than that with a displacement of 0.0 mm. The size of permanent magnet in the magnet bearing should be enlarged to improve axial attractive force in order to prevent contact between levitation impeller and pump casing.
