DEVELOPMENT AND INITIAL TESTING OF A PERMANENTLY IMPLANTABLE CENTRIFUGAL PUMP

To be able to salvage heart failure patients, the need for an economic al permanent ventricular assist device is increasing. To meet this inc reasing demand, a miniaturized centrifugal blood pump has been develop ed as a permanently implantable device. The Gyro permanently implantab le model (PI-601) incorporates a sealless design with a blood stagnati on free structure. The pump impeller is magnetically coupled to the dr iver magnet in a sealless manner. This pump is atraumatic and antithro mbogenic and incorporates a double pivot bearing system. A miniaturize d actuator was utilized in this system in collaboration with the Unive rsity of Vienna. The priming volume of this pump is 20 ml. The overall size of the pump actuator package is 53 mm in height and 65 mm in dia meter, 145 ml of displacement volume, and 305 g in weight. Testing to date has included in vitro hydraulic performance and hemolysis. This p ump can provide 5 L/min against a 110 mm Kg total pressure head at 2,0 00 rpm and 8 L/min against 150 mm Hg at 2,500 rpm. The normalized inde x of hemolysis (NIH) value of this pump was 0.0028 g/100 L at 5 L/min against 100 mm Kg. A preliminary anatomical study revealed the possibi lity of the implantability of 2 such systems in biventricular bypass a t a preperitoneal location. This system is feasible for use as a perma nently implantable biventricular assist device.