Wakisaka Y, Okuzono Y, Taenaka Y, Chikanari K, Endo S, Masuzawa T, Takano H
Department of Artificial Organs, National Cardiovascular Center Research Institute, Osaka, Japan.
Artif Organs. 1998 Jun;22(6):488-92. doi: 10.1046/j.1525-1594.1998.06130.x.
A bypass flow rate estimation and control system (BECS) for an implantable centrifugal blood pump (ICBP) has been developed in our institute. The estimated flow rate (EF) of the ICBP was derived from the electric power consumption, the rotating speed of a motor, and the blood viscosity presumed by the hematocrit and body temperature. The error in the EF was 0.5 +/- 0.4 L/min in in vivo experiments for 40 days. The rotating speed of the motor was controlled automatically every 200 ms to bring the EF in accord with the desired flow rate (DF). The reactivity and accuracy of the BECS were investigated in in vitro and in vivo experiments. The ICBP was operated by the BECS in a mock circuit in parallel with a pulsatile ventricular assist device (PVAD) to simulate left heart bypass. The reactivity was evaluated by changing the DF from 7 L/min to 5 L/min at an afterload of 160/97 mm Hg. To evaluate the accuracy of the BECS, the ICBP was driven under the aortic pressure of 110/85 mm Hg in the abdominal wall of an adult goat (70 kg). The DF was set at 5 L/min for 4 min for the goat in an awake condition. It took 13 s to change the flow rate in the in vitro experiment. The measured flow rate (MF) was maintained at 5.0 +/- 0.2 L/min by the BECS in vivo. In conclusion, the BECS has moderate reactivity and accuracy.
我们研究所已开发出一种用于植入式离心血泵（ICBP）的旁通流量估计与控制系统（BECS）。ICBP的估计流量（EF）由电力消耗、电机转速以及根据血细胞比容和体温推测的血液粘度得出。在为期40天的体内实验中，EF的误差为0.5±0.4升/分钟。电机转速每200毫秒自动控制一次，以使EF与期望流量（DF）一致。在体外和体内实验中研究了BECS的反应性和准确性。ICBP由BECS在模拟回路中与搏动性心室辅助装置（PVAD）并联运行，以模拟左心旁路。通过在160/97毫米汞柱的后负荷下将DF从7升/分钟改变为5升/分钟来评估反应性。为了评估BECS的准确性，在一只成年山羊（70千克）的腹壁中，在110/85毫米汞柱的主动脉压力下驱动ICBP。在清醒状态下，将山羊的DF设定为5升/分钟，持续4分钟。在体外实验中改变流量需要13秒。在体内，BECS将测量流量（MF）维持在5.0±0.2升/分钟。总之，BECS具有适度的反应性和准确性。
