The effects of time-delay on feedback control of depth of anesthesia

This paper presents a new procedure to find the impact of the time-delay (TD) of the patient and instrumentations such as bispectral index (BIS) monitor on closed-loop control of depth of anaesthesia during surgery. In the current work, the TD is estimated using Smith Predictive control technique. The method is validated with measured BIS signals in simulation. The results showed that the proposed procedure improves the performance of the closed-loop system for reference tracking and overall stability, and the proposed method has less overshoot, shorter settling time and is more robust to disturbances.