A model predictive sedation control system under total intravenous anesthesia

In ambulatory surgery, anesthetic drug must be administered at an appropriate rate to prevent side effects after discharge from hospital. In this study, we have been developing a sedation control system using a model predictive controller, which uses propofol as the anesthetic drug and the bispectral index (BIS) as the index of sedation, and has an identification function of the individual response and a risk control function for preventing drug over-infusion and intra-operative arousal. After obtaining the approval from the Ethics Committee of Kyoto University Hospital, 80 clinical trials were made from July 2002. The results show that our system can reduce propofol infusion dose, and can maintain the BIS more accurately than manual administration.