Development of disposable self-regulating blood pumps and portable automatically-controlled ECMO systems for cardiopulmonary support.

为了减少新生儿体外乳膜氧合(ECMO)管理的工作量和安全性，我们一直在研究ECMO设备的自动控制。在本研究中，我们使用Takagi的自调式血泵对ECMO系统进行了改进，以供临床使用。最新的血泵由一对管状血腔、改装的球阀、驱动空气的外壳和光电传感器组成。血腔和瓣膜是一次性的，价格低廉。最新的驱动和控制机是由现成的心脏辅助装置改装而成，具有“自动”、“延迟”和“恒定”三种驱动模式。当ECMO以最大旁路流量运行时，使用“自动”模式；当ECMO退出时，“恒定”模式用于低旁路流量。“延迟”模式使ECMO流量能够在自动控制下从10毫升/分钟轻松变化到450毫升/分钟，并在ECMO流量逐渐减少以进行断奶时使用。这种驾驶机器也是由电池驱动的，而且是便携的，有可能在ECMO的支持下运送垂死的儿童。在模拟电路上和动物实验中研究了最新泵系统的性能。临床应用2例，其中1例为左肺巨大CCAM，1例为先天性膈疝，ECMO持续时间为142~168小时。两名患儿均成功脱机，其中一名存活，无任何后遗症。由于我们的血泵系统能够根据血流动力学自动改变ECMO流量，因此没有必要连续观察ECMO泵，也没有必要仅为了稳定泵的性能而输注血液材料。对血细胞的损伤明显减少，因此，1例CCA患者在ECMO过程中不输注血小板。我们的ECMO电路所需人员较少，有利于血液学检查。

To make the neonatal extracorporeal mambrane oxygenation (ECMO) management less laborious and safer, we have been investigating automatic control of the ECMO apparatus. In this study, we modified the ECMO system using Takagi's self-regulating blood pumps for the clinical use. The newest blood pump consists of a pair of tube-type blood chambers, modified ball valves, housings for driving air, and photosensors. Blood chambers and valves are disposable at low prices. The newest driving and control machine, which was modified from the ready-made ventricular assist device, possesses three modes of drive, " Automatic", "Delay", and "Constant". The "Automatic" mode is used when ECMO runs at a maximum bypass flow, and the "Constant" mode for a low bypass flow when ECMO is withdrawn. The "Delay" mode enables ECMO flow to change easily from 10 to 450 ml/min under automatic control, and used when an ECMO flow is gradually decreased for weaning. This driving machine is battery-driven as well and portable, and it is possible that a moribund child can be transported as he/she is under ECMO support. The performance of the newest pump systems was investigated on a simulation circuit and by using animals. This new ECMO circuit was clinically used in 2 neonates, one having huge-sized CCAM of the left lung and another congenital diaphragmatic hernia, with the ECMO duration being 142 to 168 hours. Both children were successfully weaned from ECMO and one survived without any sequelae. Because our blood pump systems enable to change the ECMO flow automatically in response to hemodynamics, it is not necessary to observe the ECMO pump incessantly nor to infuse blood materials only for the purpose of stabilizing the pump performance. Injury to blood cells was significantly less, therefore, platelet was not transfused during the ECMO course in one patient with CCAM.Our ECMO circuit required less personnel and was favorable for hematological findings.