Controlling the Depth of Anesthesia During Operation by Vital Parameters of the Patient’s Body Using a Fuzzy Controller

Controlling the level of anesthesia is a very complex, difficult and important process in which precision and performance is very important. Fuzzy controllers are one of the most efficient methods compared to other controllers, due to the impact of the expert in the rule set and determining the dosage based on the expert's knowledge. Due to the high complexity of anesthesia, synthesizing the theoretical models of the physiological principles is difficult. In this research, the modeling strategy is developed using fuzzy logic by considering the minimum cost in equipment and time. To develop a simple, economic and reliable method to control the depth of anesthesia, parameters such as mean blood pressure, heart rate, age and weight are considered as the model input. The proposed method is applied to 10 patients in caesarean section in Isfahan hospital and the simulation results are compared with the dose injected by the anesthesiologist. The experiment results show that the mean error rate of the results of the proposed method and the exact dose injected to patients is 13% for fentanyl and 3/2% for Morphine, which proves that the Morphine error rate is much lower compared to the error rate of the initial dose injected by anesthesiologist before surgery.