Abstract
A magnetically suspended centrifugal pump (MSCP) has been developed for long term use. The size of the pump is 82×51 mm weighing 420 g. The power required is 15 w. Chronic animal studies were performed in three sheep. The blood was withdrawn from the left ventricular apex, and returned to the descending aorta. The pumps were positioned outside the body in two and inside the body (outside the thoracic wall) in one sheep. The pumping flow was estimated by indirect method using the motor current and rotational speed. The pumping flow was 3.5-6.5 L/min. The free hemoglobin level was less than 25 mg/dl. The duration of animal experiments were 60, 140, and 80 days+(ongoing). The temperature of the pump surface was around 42°C. No thrombus was observed even after 140 days support. In conclusion, the MSCP was promising device for an implantable assist heart.
