Analysis of an individualized physiologically based model for anesthesia control

This paper presents a physiologically based, patient-specific, compartmental model for volatile anesthesia, consisting of a multiple blood and tissue compartmental model, adjusted to the weight, height, sex and age of the patient. The predicted hypnotic effect measured by the Bispectral Index is linked to the arterial anesthetic concentration by an effect site compartment and the Hill-Equation. To gain an in-depth understanding about the influence of individual patient variables and characteristics, the pharmacokinetic and pharmacodynamic variables are analyzed for application of the model in future model predictive control. In this study the pharmacodynamic variables are identified to have a higher influence on the modeling output and are therefore more important to be identified accurately. The initial sensitivity of the patient is calculated based on default physiological variables and updated during the course of anesthesia as a function of the obtained measurement of the Bispectral Index.