Human-Imitating Control of Depth of Hypnosis Combining MPC and Event-Based PID Strategies

In this letter we propose a human-imitating control methodology for the Depth-of-Hypnosys (DoH) in total intravenous anesthesia (TIVA) where the bispectral index (BIS) is used as process variable. The method suitably combines a move-blocking model predictive controller (MPC) that minimizes the time-to-target when the BIS value is not in the required range and an event-based Proportional-Integral-Derivative (PID) controller that provides a strong filtering action when the DoH is satisfactory. A fast induction is achieved and awareness episodes are avoided with a control action that is piecewise constant so that it mimics the behavior of the anesthesiologist and is more likely to be accepted in the clinical practice.