Development of an electrohydraulic total artificial heart at the National Cardiovascular Center, Osaka, Japan.
The authors have been developing an electrohydraulic total artificial heart with a basic concept placing the blood pumps and an electrohydraulic energy converter separately, in the thorax and the abdominal region, respectively, to minimize anatomic constraints. Major problems of the system were a high energy consumption of 56 W at 6 L/min output and an insufficient maximum output of 6.7 L/min. The energy converter was redesigned to overcome these problems. A three phase, 4 pole brushless DC motor, which has maximum efficiency of 79% at a motor rotation of 2500 rpm with a load of 0.1 Nm, was developed for the new energy converter. Flow-channel design of the regenerative oil pump was optimized, which resulted in increasing the maximum flow rate at one directional motor rotation from 18 to 29 L/min. In vitro performance of the electrohydraulic total artificial heart was evaluated in a mock circulation with physiologic pressure conditions. Maximum output was increased to 10.7 L/min at a pump rate of 120 bpm and energy consumption of the motor at 6 L/min output was reduced to 18 W. Based upon these favorable results, the system is now being assembled for chronic animal implantation.
Masuzawa
T
T
Department of Artificial Organs, National Cardiovascular Center Research Institute, Osaka, Japan.
Taenaka
Y
Y
Tatsumi
E
E
Choi
W W
WW
Toda
K
K
Ohno
T
T
Baba
Y
Y
Nakatani
T
T
Takano
H
H
Uyama
C
C
D000818:Animals; D001698:Biomedical Engineering; D002302:Cardiac Output; D004582:Electronics, Medical; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D006354:Heart, Artificial; D006801:Humans; D066298:In Vitro Techniques