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Development of a closed loop control system for total intravenous anesthesia

全静脉麻醉闭环控制系统的研制

基本信息

批准号：
04454387
负责人：
IKEDA Kazuyuki
金额：
$ 4.03万
依托单位：
Hamamatsu University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

The purpose of this study was to develop a closed loop control system for total intravenous anesthesia. This system was divided into four subsystems as follows ;(1) Subsystem to quantify anesthesia depthTo quantify anesthesia depth, a real time spectral analyzer of the heart rate variability and a computer program to analyze power spectra of electroencephalograph were developed. A precise method for carbon dioxide tension measurement in expiratory gas was also studied.(2) Subsystem to estimate concentrations of anesthetic agents in blood within brief durationConcentrations of anesthetic agents ; midazolam, thiopental, pentazocine and vecuronium, were estimated using high performace liquid chromatography. An interval between blood sampling and estimation of blood concentration was less than twenty minutes.(3) Subsystem to simulate concentrations of anesthetic agents in blood and effect sitesA computer program to simulate anesthetic agents in blood and effect sites was studied. To calculate the concentrations, the Euler method or the Runge-Kutta-Gill method was applied. Influences of aging on pharmacokinetics and pharmacodynamics of midazolam were studied to improve the precision of the simulation.(4) Subsystem to control syringe pumps using a computerA computer program to simultaneously control three syringe pumps was studied. This system enabled estimation of the time required for reaching the presetting concentrations of the agents in blood.Muscle relaxants were able to be infused by a closed loop control method using a neuromuscular junction monitor. Since methods for estimation of effects of analgesics and hypnotics have not been completed, it is impossible to infuse those agents using a closed loop control method. Analgesics and hypnotics were infused by an open loop control method according to values of concentrations of the agents simulated. The differences between actual and simulated concentrations were corrected by the values measured in blood.

本研究的目的是开发一个全静脉麻醉的闭环控制系统。本系统分为以下四个子系统：(1)麻醉深度量化子系统为量化麻醉深度，开发了心率变异性实时频谱分析仪和脑电图功率谱分析计算机程序。研究了呼气气体中二氧化碳张力的精确测量方法。(2)用于估算短时间内血液中麻醉剂浓度的子系统。采用高效液相色谱法对咪达唑仑、硫喷妥钠、戊唑嗪和维库溴铵进行了测定。血液采样与血药浓度估计之间的间隔小于20分钟。(3)模拟麻醉药物血药浓度及作用部位的子系统研究了模拟麻醉药物血药浓度及作用部位的计算机程序。采用欧拉法或龙格-库塔-吉尔法计算浓度。研究衰老对咪达唑仑药代动力学和药效学的影响，提高模拟的精度。(4)利用计算机控制注射泵的子系统，研究了同时控制3台注射泵的计算机程序。该系统能够估计达到血液中药物预设浓度所需的时间。肌肉松弛剂能够通过使用神经肌肉连接监测器的闭环控制方法注入。由于估计镇痛药和催眠药效果的方法尚未完成，因此不可能使用闭环控制方法注入这些药物。根据模拟药物的浓度值，采用开环控制方法注射镇痛药和催眠药。实际浓度和模拟浓度之间的差异通过血液中的测量值进行校正。