Ripple reduction control of the undulation pump total artificial heart.
An undulation pump total artificial heart (UPTAH) in which the revolutions of the motor are converted to undulation motion of a disk has been developed. In an experiment, a goat using the UPTAH survived for 54 days. However, a large ripple was observed in the device's output pressure and flow waveform. In calculating the spectrum of the ripple, we found that the ripple mainly comprised 2 frequency sine waves: 1 having the same frequency as and 1 having double the frequency of the motor revolutions. To reduce the ripple, 2 sine waves, 1 having the same frequency as and 1 having double the frequency of the motor revolutions, were provided to the motor current to modulate the pulse width of the pulse width modulation controlling the motor revolutions. This ripple control method reduced the pressure ripple by 90% in a mock circulation and by 70% in animal experiments. These results revealed that the ripple generated in the UPTAH could be controlled through the use of motor control software.
Saito
Itsuro
I
Research Center for Advanced Science and Technology, Tokyo, Japan. saito@bme.rcast.u-tokyo.ac.jp
Chinzei
Tsuneo
T
Mochizuki
Shuichi
S
Abe
Yusuke
Y
Isoyama
Takashi
T
Iwasaki
Kiyotaka
K
Suzuki
Takafumi
T
Karita
Tatsuro
T
Ono
Toshiya
T
Kouno
Akimasa
A
Ishimaru
Mitsuhiko
M
Baba
Atsushi
A
Ozeki
Toshinaga
T
Tohyama
Takahiro
T
Kobayashi Si
Shin-ichi
S
Imachi
Kou
K
D000818:Animals; D006041:Goats; D006354:Heart, Artificial; D011673:Pulsatile Flow; D012399:Rotation