Passivity based fractional order adaptive control of depth of anesthesia

Abstract

In this paper, a passivity based model reference adaptive controller with fractional-order adaptation mechanism is utilized for control of depth of anesthesia. The propofol infusion rate is adjusted to reach an appropriate Bispectral Index (BIS). The Pharmacokinetic-Pharmacodynamic (PK-PD) model is employed to model the distribution of propofol in patient body. Since, the PK-PD model parameters depend on physical specifications of patient, employing an adaptive controller to control this system is inevitable. The utilized controller is a pole placement controller in which its polynomial coefficients are adjusted according to a fractional-order adaptation mechanism. Simulation results on several patients demonstrate the efficiency of the proposed method in the presence of disturbance, noise, and model uncertainties.