A hypnosis control system using a model predictive controller with online identification of individual parameters

For the purpose of maintaining hypnosis level of patients during general anesthesia appropriately, we have developed a hypnosis control system with a function of online identification of individual parameters. As the control strategy, model predictive control, which can take the dead time included in the bispectral index (BIS) response to propofol infusion into account rigorously, is used. The online identification function obtains pharmacodynamic parameters and the dead time for each individual patient from the BIS response for the first few minutes of anesthesia induction. With the approval by the Ethics Committee of Kyoto University Hospital, the system was applied clinically, and its effectiveness in maintaining hypnosis level accurately and reducing the amount of propofol infusion was confirmed