CURRENT PROGRESS IN THE DEVELOPMENT OF A TOTALLY IMPLANTABLE GYRO CENTRIFUGAL ARTIFICIAL-HEART

A totally implantable centrifugal artificial heart has been developed using a miniaturized pivot bearing supported centrifugal pump (Gyro PI pump). The authors report current progress in its development. The Gy ro PI-601 has a priming volume of 20 mi, weighs 100 g, has a height of 60 mm, and has a diameter of 65 mm. This pump can provide 8 L/min aga inst 150 mmHg at 2,250 rpm. It is driven by an miniaturized DC brushle ss motor with the coils fixed in a plastic mold that is waterproof and made of titanium (weight, 204 g; height, 18 mm; diameter, 65 mm). In this centrifugal artificial heart, two Gyro PI pumps are implanted ind ependently to replace cardiac function without resecting the native he art. Its anatomic and surgical feasibility were confirmed experimental ly. The Gyro PI-601: was implanted as a right or left ventricular assi st device in the preperitoneal space of five calves. All five tests pr oceeded without any thromboembolic symptoms. One of five tests was ext ended more than 1 month to confirm the long-term feasibility of the Gy ro PI-601 pump system. Based on the satisfactory results of the in viv o tests, the material conversion of the Gyro PI from polycarbonate to titanium alloy (Ti-6A1-4V) was undertaken to improve its biocompatibil ity for long-term implantation.