A Study on Anesthesia Control Considering Time Variabllity of Kinetics and Effect of Anesthetic Drugs

在本研究中，我们研究了一个麻醉控制系统，考虑到手术过程中的动力学和麻醉药物的效果的时间变异性。 首先，我们建立了一个具有时变清除率的药代动力学模型，该模型反映了麻醉药丙泊酚催眠作用的时间变异性。 利用该模型，可以保持适当的催眠维持在一个恒定的水平，估计效应室丙泊酚浓度。 其次，我们证实了镇痛/伤害感受指数作为镇痛指标比现有指标更有效，并构建了一种考虑丙泊酚和瑞芬太尼（镇痛药）相互作用的催眠和镇痛控制方法。 仿真结果表明，所开发的控制方法可以保持适当的催眠和镇痛，如果在手术开始时达到足够的镇痛。

In this research, we have studied an anesthesia control system considering time variability of kinetics and effect of anesthetic drugs during surgery. First, we developed a pharmacokinetic model with a time-varying clearance, which represents time variability of hypnotic effect of propofol, an anesthetic drug. Utilizing the model, hypnosis can be kept properly by maintaining estimated effect-site concentration of propofol at a constant level. Second, we confirmed that Analgesia/Nociception Index is more effective as an analgesia index than existing indices, and constructed a hypnosis and analgesia control method considering interaction of propofol and remifentanil, an analgesic drug. Simulation results show that the developed control method can maintain hypnosis and analgesia appropriately if sufficient analgesia is achieved at the beginning of surgery.