Abstract
Performance and characteristics are compared among the artificial hearts made in Hiroshima University. A brushless dc motor, Harmonic Drive reduction gears, and a cylindrical cam are used in one artificial heart, an ultrasonic motor and a crank chain in the second artificial heart, a brushless dc motor with a worm gear or with a gear head and a link mechanism in the third. Blood chambers made of Biomer are cylindrical or lenticular in accordance with the form of the pushers. An ultrasonic motor has large torque with slow speed, but the test result shows that the ultrasonic motor at present is not so powerful as to meet the demand of our artificial heart. Camfollowers used with the cylindrical cam are worm out in some extent. The motion of the pusher is linear reciprocation with the crank chain or with the cylindrical cam, but it is swing motion with the link mecha-nism. The motor is required as small as possible, of which speed and power are 40-150rpm and 15W, respectively.
