Robust sliding mode control for precision anesthesia delivery: Addressing interpatient variability in depth of hypnosis

Anesthesia induction is a critical aspect of ensuring patients' health and safety during surgical procedures. The manual administration of anesthesia can lead to serious medical issues due to variability among patients, as well as the risks of overdosing or underdosing anesthetic drugs. While various linear control techniques have been implemented to enhance the safety of anesthesia infusion, non-linear control strategies have demonstrated superior results in achieving the desired level of hypnosis for surgical activities, primarily due to the significant parametric variations present in different patients.Given these challenges, there is a pressing need to develop an efficient anesthesia infusion system that optimizes drug delivery and improves post-anesthesia recovery. This paper focuses on designing a non-linear controller using a robust control strategy known as Sliding Mode Control (SMC). This controller aims to accurately manage drug infusion while maintaining the appropriate level of hypnosis during surgery. The performance of the designed controller has been evaluated with patients exhibiting different clinical parameters. Simulation results show that all patients achieved the target Bispectral Index (BIS) level of 40-60 without any signs of overdose, thus ensuring a safe procedure for surgery. In this paper, we demonstrate that the BIS level of the 50 scale index has improved, achieving levels in the 80s to 100s instead of the previously aimed BIS level of 145 to 150. The patient is expected to reach the BIS level early and attain the hypnotic stage in the 80s within the required time.