Ahn J M, Masuzawa T, Taenaka Y, Tatsumi E, Ohno T, Choi W W, Toda K, Miyazaki K, Baba Y, Nakatani T, Takano H, Min B G
Department of Artificial Organs, National Cardiovascular Center, Osaka, Japan.
ASAIO J. 1996 Sep-Oct;42(5):M584-9. doi: 10.1097/00002480-199609000-00055.
In an electrohydraulic total artificial heart developed at the National Cardiovascular Center (Osaka, Japan), two blood pumps are pushed alternatively by means of the bidirectional motion of a brushless DC motor for pump systole and diastole. Improvement in the dynamic response of the motor is very important to obtain better pump performance; this was accomplished by using power electronic simulation. For the motor to have the desired dynamic response, it must be commutated properly and the damping ratio (zeta), which represents transient characteristics of the motor, must lie between 0.4 and 0.8. Consequently, all satisfactory specifications with respect to power consumption must be obtained. Based on the simulated results, the design criteria were determined and the precise controller designed to reduce torque ripple and motor vibration, and determine motor stop time at every direction change. In in vitro tests, evaluation of the controller and dynamic response of the motor was justified in terms of zeta, power consumption, and motor stop time. The results indicated that the power consumption of the controller and the input power of the motor were decreased by 1.2 and 2.5 W at zeta = 0.6, respectively, compared to the previous system. An acceptable dynamic response of the motor, necessary for the reduction of torque ripple and motor vibration, was obtained between zeta = 0.5 and zeta = 0.7, with an increase in system efficiency from 10% to 12%. The motor stop time required for stable motor reoperation was determined to be over 10 msec, for a savings in power consumption of approximately 1.5 W. Therefore, the improved dynamic response of the motor can contribute to the stability and reliability of the pump.
在日本大阪国立心血管中心研发的一款电动液压全人工心脏中，两个血泵通过无刷直流电机的双向运动交替推动，以实现泵的收缩和舒张。改善电机的动态响应对于获得更好的泵性能非常重要；这是通过电力电子模拟实现的。为使电机具有所需的动态响应，必须正确进行换向，并且代表电机瞬态特性的阻尼比（ζ）必须在0.4至0.8之间。因此，必须获得关于功耗的所有令人满意的规格。基于模拟结果，确定了设计标准，并设计了精确的控制器，以减少转矩脉动和电机振动，并确定每次方向改变时的电机停止时间。在体外测试中，根据ζ、功耗和电机停止时间对控制器和电机的动态响应进行了评估。结果表明，与先前系统相比，在ζ = 0.6时，控制器的功耗和电机的输入功率分别降低了1.2 W和2.5 W。在ζ = 0.5至ζ = 0.7之间获得了电机可接受的动态响应，这对于减少转矩脉动和电机振动是必要的，系统效率从10%提高到了12%。确定稳定电机重新运行所需的电机停止时间超过10毫秒，可节省约1.5 W的功耗。因此，电机动态响应的改善有助于提高泵的稳定性和可靠性。
