Development of a remote-controlled, automated total intravenous anesthesia system

本研究的目的是开发一种远程计算机控制的全静脉麻醉（TIVA）系统，该系统使用三种麻醉药物：异丙酚催眠、芬太尼镇痛和维库溴铵肌松，我们初步开发了一种药物的靶控输注（TCI）系统，包括个人计算机、计算机控制的输注泵和自制的软件。该系统基于药代动力学和药效学模型计算估计的血药浓度或估计的效应部位浓度，并控制输注速率以维持所需浓度。我们增加了一个四串口的PCI卡，用一台计算机控制三台输液泵，以脑电双频指数作为催眠水平，以单次抽动高度作为肌肉松弛的指标。然后我们开发了一个系统来控制三种药物的输注速率。对于丙泊酚，通过实时处理计算脑电双频指数与估计的效应部位浓度之间的关系，并控制丙泊酚输注速率以维持所需的脑电双频指数值。对于维库溴铵，系统反馈单次抽搐高度并控制维库溴铵输注速率。将该系统与芬太尼TCI相结合，应用于实际麻醉实践，产生了稳定的麻醉效果，最后通过远程控制软件，在我院局域网上，通过其它个人计算机对该系统进行远程控制。我们将该最终系统用于一些患者，并可诱导和维持稳定的麻醉。我们期望在不久的将来，许多临床医生将使用一个完全自动化的麻醉系统，该系统集成了其他生理信息并控制麻醉机、输液等。

The object of this study is to develop a remote computer-controlled system for total intravenous anesthesia (TIVA) using three anesthetic drugs : propofol for hypnosis, fentanyl for analgesia, and vecuronium for muscle relaxation.We initially developed a target-controlled infusion (TCI) system of a drug that includes a personal computer, a computer-controlled infusion pump, and a self-made software. This system calculates estimated blood concentration or estimated effect-site concentration based on the pharmacokinetic and pharmacodynamic model, and controls the infusion rate to maintain a desired concentration. We added a 4-serial-port PCI-card to control three infusion pumps by one computer.As the information from a patient, the Bispectral Index for hypnotic level and the single twitch height for muscle relaxation were used. Then we developed a system to control infusion rates of three drugs. For propofol, that calculates the relation between the Bispectral Index and the estimated effect-site concentration by real-time processing and controls the propofol infusion rate to maintain a desired Bispectral Index value. For vecuronium, the system feedbacks the single twitch height and controls the vecuronium infusion rate. Adding the TCI of fentanyl, this, one computer three pumps system were used in actual anesthesia practice and produced stable anesthesia.Finally we remote-controlled the former system by other personal computer via LAN within our hospital using remote-control software. We used this final system to some patients and could induce and maintain stable anesthesia. We expect that in the near future, many clinicians will use a completely automated anesthesia system that integrating other physiological information and controlling ventilators, fluid infusion, etc.