Fuzzy modeling and simulation for regulating the dose of anesthesia

Most surgical operation need an anesthetic agent to administer for obtaining a local or general anesthetic condition of a patient. General anesthesia affects the brain cells and puts the patient unconscious, pain free, immobile and free from memory. It is a challenge to the anesthetist to administer a proper dose of anesthetic agent for required depth of anesthesia. In most situations it is a decision by anesthetist measuring physiological parameters of blood pressure and pulserate to administer the proper dose of anesthetic agent. The authors in this paper present a concept and use of fuzzy controller to administer a proper dose of anesthetic agent eliminating a manual task based on the physiological parameters of systolic and diastolic blood pressure and pulse rate of a patient to obtain a required depth of anesthesia. The method is based on the analysis of these variables by giving membership function, evaluation of rule based system and defuzzification process to control the depth of anesthesia and decide required dose of anesthetic agent. Isoflurane is taken as anesthetic agent. MATLAB fuzzy logic tool box is used for simulation of the system.