IMPLANTABLE CENTRIFUGAL PUMP WITH HYBRID MAGNETIC BEARINGS

Test methods and results of in vitro assessment of a centrifugal pump with a magnetically suspended impeller are provided. In vitro blood te sts have been completed with a resulting normalized milligram index of hemolysis (NmIH) of 12.4 +/- 4.1, indicating that hemolysis is not a problem. Hydraulic characterization of the system with water has shown that a nominal pumping condition of 6 L/min at 100 mmHg was met at 2, 200 rpm. Maximum clinically usable cardiac output is predicted be 10 L /min. The magnetic bearing supported impeller did not contact the hous ing and was shown to be stable under a variety of pumping conditions. The driving motor efficiency is 75% at the nominal condition. Finally, a description of the clinical version of the pump under development i s provided.