Tanaka Akira, Yoshizawa Makoto, Abe Ken-ichi, Takeda Hiroshi, Yambe Tomoyuki, Nitta Shin-ichi
Department of Electrical and Communication Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan.
Artif Organs. 2003 Jan;27(1):99-103. doi: 10.1046/j.1525-1594.2003.07175.x.
To avoid using sensors with low biocompatibility and low durability in implantable total artificial heart (TAH) systems, the authors previously proposed a new method for estimating instantaneous values of flow rate and pressure head on the basis of voltage, current, and rotational speed in a motor driven centrifugal pump. The previous in vitro experiments showed that the proposed estimator could automatically compensate for the effect of the change in blood viscosity on the estimation accuracy by employing two kinds of autoregressive exogenous models. In this study, validity and reliability of this estimation method were ascertained in an acute animal experiment. In the experiment, two centrifugal blood pumps were implanted into an adult goat as a total artificial heart. Results of estimation were compared with true values when blood viscosity was changed by injecting physiological saline. The results indicated that the system could successfully estimate pressure head by compensating the change of viscosity, although the estimation accuracy of the in vivo estimation was not so high as that of the previous in vitro tests.
为避免在植入式全人工心脏（TAH）系统中使用生物相容性低且耐久性差的传感器，作者此前提出了一种基于电动离心泵中的电压、电流和转速来估算流量和压头瞬时值的新方法。先前的体外实验表明，所提出的估计器通过采用两种自回归外生模型，能够自动补偿血液粘度变化对估计精度的影响。在本研究中，通过急性动物实验确定了该估计方法的有效性和可靠性。在实验中，将两个离心血泵作为全人工心脏植入一只成年山羊体内。通过注射生理盐水改变血液粘度时，将估计结果与真实值进行了比较。结果表明，尽管体内估计的精度不如先前的体外测试高，但该系统能够通过补偿粘度变化成功估算压头。
