Individualized control of the depth of anesthesia based on online identification and retuning

摘要

In this paper a control scheme based on a simplified model for the joint action of propofol and remifentanil on the depth of anesthesia, measured by the BIS level, is proposed. The simplified model contains four patient dependent parameters, two of which can be easily estimated from the patient’s BIS response to an initial bolus of propofol. Instead of estimating the remaining necessary parameters, initial guesses are assumed for these parameters in order to compute the drug dosages corresponding to a desired reference BIS level by steady-state model inversion.The dosages are updated by means of a successive retuning procedure that ensures that the patient’s BIS response achieves and maintains the desired reference level. This successive retuning scheme yields betters results than a single retuning procedure by decreasing the settling time at the target BIS value.