Development of a centrifugal blood pump with magnetically suspended impeller and the related fluid mechanical problems

This paper deals with fluid mechanical problems encountered in eight years of developmental studies on a centrifugal blood pump with magnetically suspended impeller. The main results of the investigation are as follows. The impeller disk friction is dominant among all the power losses; the magnetically suspended impeller with radial straight vanes is the most stable. Motor current depends on blood viscosity and flow rate. Consequently, the flow rate and pressure difference can be estimated by self-sensing without any need for flowmeter and pressure transducers.