Advance in animal experiments with the undulation pump total artificial heart: 50 and 54 day survival periods with 1/R control.
The undulation pump total artificial heart (UPTAH) is a unique, implantable, total artificial heart (TAH) that uses undulation pumps. To achieve long-term survival in animals with physiologic hemodynamic conditions, a control method based on conductance and arterial pressure was applied to UPTAH. With this control method, called 1/R control, survival periods of 50 days (No. 0016, 49.6 kg) and 54 days (No. 0030, 42.5 kg) were obtained in adult female goats. In No. 0016, 1/R control was applied to the left pump, whereas in No. 0030, it was applied to the right pump. Another pump was used for left-right balance control. The control stability was better in No. 0030 than in No. 0016. The sucking effect of the left atrium was remarkable in No. 0016, possibly because of a time delay when left-right balance control was performed with the right pump. In No. 0016, the cause of death was probably a thrombus flown from a panus in the left atrium. It is possible that the left atrial suction effect influenced the thrombus and panus formation in the left atrium. In No. 0030, the cause of death was a small rupture of the membrane in the right pump. The rupture may have been caused by excessive negative pressure inside the pump. This pressure resulted from suction of the right atrium because of an unexpected control excursion, which was probably caused by a software bug. It will be necessary to redesign the undulation pump and improve the software to achieve longer survival periods for animals with physiologic hemodynamic conditions.
Abe
Yusuke
Y
Department of Biomedical Engineering, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Chinzei
Tsuneo
T
Isoyama
Takashi
T
Kobayashi
Shinichi
S
Ono
Toshiya
T
Saito
Itsuro
I
Iwasaki
Kiyotaka
K
Ishimaru
Mitsuhiko
M
Baba
Atsushi
A
Kouno
Akimasa
A
Ozeki
Toshinaga
T
Tohyama
Takahiro
T
Imachi
Kou
K
D000818:Animals; D002302:Cardiac Output; D005260:Female; D006041:Goats; D006354:Heart, Artificial; D006439:Hemodynamics / Q000502:physiology*; D011474:Prosthesis Design