Comparing different identification approaches for the depth of anesthesia using BIS measurements

Depth of anesthesia is usually quantified by the Bispectral Index (BIS) and refers to both loss of consciousness, resulting from the administration of a hypnotic like propofol, and inhibition of pain, resulting from the administration of an analgesic like remifentanil. This paper addresses the mathematical modeling of the joint effect of propofol and remifentanil in the depth of anesthesia, using BIS measurements. Two models and identification strategies are considered. The first model is based on standard pharmacokinetic/pharmacodynamic models and the associated identification strategy corresponds to the application of a hybrid method. The second model has a minimal number of parameters and the associated identification strategy corresponds to the application of a prediction error method. These two approaches are tested and compared on real data.