Increasing Robustness of the Anesthesia Process from Difference Patient's Delay Using a State-Space Model Predictive Controller

Abstract

The process of anesthesia is nonlinear with time delay and also there are some constraints which have to be considered in calculating administrative drug dosage. We present an Extended Kalman Filter (EKF) observer to estimate drug concentration in the patient's body and use this estimation in a state-space based Model of Predictive Controller (MPC) for controlling the depth of anesthesia. Bispectral Index (BIS) is used as a patient consciousness index and propofol as an anesthetic agent. Performance evaluations of the proposed controller, the results have been compared with those of a MPC controller. The results demonstrate that state-space MPC including the EKF estimator for controlling the anesthesia process can significantly increase the robustness in encountering patients' delay deviations in comparison with the MPC. . Keywords: Depth of Anesthesia (DOA); Patient's delay; PK-PD model; Model based Predictive Controller (MPC)

AnesthesiaGUIDE: a MATLAB tool to control the anesthesia

“…The obtained differential equations describing the PK/PD model are similar to those presented by Schneider in [9][10][11][12][13][14]:…”

“…The results show the controller's capability to achieve and maintain the desired hypnosis level. The duration of the transient responses (induction phase), 50 s, is lesser than in other studies from the literature [7,9,12].…”

“…In this work, a four-compartment model of the patient hypnotic state under propofol (hypnotic drug) infusion rate was developed using MATLAB's SimBiology toolbox [13]. It is based on a block diagram available in many related papers from the literature [9][10][11][12][13][14].…”

“…In the literature, many closed-loop anesthesia systems are proposed. Some relevant examples may be mentioned here: Ilyas proposed a sliding-mode control algorithm [6] [7], Khaqan developed a nonlinear strategy [8], Navarro designed a fractional-order closed-loop model reference adaptive control based on a fractional-order model [9], Mendez used fuzzy predictive control techniques [10], Caiado investigated H-inf robust control [11], Reznanian developed a predictive controller [12], Usharani developed a PID controller strategy [16], Pasin performed a metaanalysis comparing closed-loop with manual drug delivery [17], Sopasakis built a fractional pharmacokinetics model https://doi.org/10.1007/s42452-021-04885-x [18], and Gonzalez-Cava proposed a study where an adaptive model deal simultaneously with the variabilities in the clinical response of the patients [19]. Actual trends and challenges are presented by Ghita in [20] and Zaouter in [21].…”

Performance of Classical PID Tuning in the Automation Anesthesia Delivery

“…Thus, in this article, the PD and PK models consider propofol infusions exclusively [5,10], leading to a mathematical model described by a linear third-order system with a nonlinear static output. Other models consider delay or fuzzy variables to describe this phenomenon or different anesthetic agents as remifentanil [8,11].…”