Abstract
We conducted measurements of the radial displacement of the impeller of the centrifugal blood pump which our research group developed, and investigated the effect of the whirling motion of the impeller on the stability of the impeller positions. This study investigated the effect of the configuration of the impeller and the casing on the whirling motion. The amount of leakage flow entering the impeller/casing gap due to the pressure difference had a important role in determining frequency of the whirling motion. The casing having two symmetrical outlet port greatly contributed in minimizing the radial thrust and the shift of the impeller position. The locus under the sudden shutoff of the circuit do not show any deviation from the loci measured under steady flow conditions.
