Schäublin J, Derighetti M, Feigenwinter P, Petersen-Felix S, Zbinden A M
Institute of Anaesthesiology and Intensive Care, University Hospital, Bern, Switzerland.
Br J Anaesth. 1996 Nov;77(5):636-41. doi: 10.1093/bja/77.5.636.
We have examined a new approach, using fuzzy logic, to the closed-loop feedback control of mechanical ventilation during general anaesthesia. This control system automatically adjusts ventilatory frequency (f) and tidal volume (VT) in order to achieve and maintain the end-tidal carbon dioxide fraction (FE'CO2) at a desired level (set-point). The controller attempts to minimize the deviation of both f and VT per kg body weight from 10 bpm and 10 ml kg-1, respectively, and to maintain the plateau airway pressure within suitable limits. In 30 patients, undergoing various surgical procedures, the fuzzy control mode was compared with human ventilation control. For a set-point of FE'CO2 = 4.5 vol% and during measurement periods of 20 min, accuracy, stability and breathing pattern did not differ significantly between fuzzy logic and manual ventilation control. After step-changes in the set-point of FE'CO2 from 4.5 to 5.5 vol% and vice versa, overshoot and rise time did not differ significantly between the two control modes. We conclude that to achieve and maintain a desired FE'CO2 during routine anaesthesia, fuzzy logic feedback control of mechanical ventilation is a reliable and safe mode of control.
我们研究了一种采用模糊逻辑的新方法，用于全身麻醉期间机械通气的闭环反馈控制。该控制系统会自动调整通气频率（f）和潮气量（VT），以将呼气末二氧化碳分数（FE'CO2）维持在所需水平（设定值）。控制器试图将每千克体重的f和VT分别与10次/分钟和10毫升/千克的偏差降至最低，并将平台气道压力维持在合适范围内。在30例接受各种外科手术的患者中，对模糊控制模式与人工通气控制进行了比较。对于FE'CO2设定值为4.5%（体积分数）且测量时间为20分钟的情况，模糊逻辑控制和人工通气控制在准确性、稳定性和呼吸模式方面没有显著差异。在FE'CO2设定值从4.5%（体积分数）阶跃变化到5.5%（体积分数）以及相反变化后，两种控制模式的超调量和上升时间没有显著差异。我们得出结论，在常规麻醉期间，为实现并维持所需的FE'CO2，机械通气的模糊逻辑反馈控制是一种可靠且安全的控制模式。
