Rotational stability of the monopivot centrifugal blood pump with a magnetic coupling

摘要

It is necessary to improve rotational stability of an implantable artificial heart to enhance mechanical durability and biocompatibility. To clarify rotational stability regarding the magnet geometry of a monopivot centrifugal pump for artificial heart, an experimental simulation model was made with the same magnet geometry. The swinging motion of the impeller was measured with a laser displacement meter. It was found that the magnetic coupling is stable to radial translations and unstable to inclinations. However, rotational stability can be achieved when the distance between the magnetic bearing and the pivot bearing is more than a certain value determined by static tests of the magnet coupling. It was found that the inverse pivot configuration is also useful to the system stability.