Monitoring approaches in general anesthesia: a survey.

The aim of this article is to give an overview of recent developments in the field of general anesthesia monitoring. We measure different physiological signals related to the functioning of several nervous systems. Using statistical or signal processing methods, monitors are derived and correlated to the dosage of anesthetic agents and to the status of the patient. Comparisons among existing monitors show that there is no one universal monitor applicable to all general anesthesia--each has its own characteristics and might be useful in particular clinical situations. Modeling of the underlying physiological mechanisms of the anesthesia may help for better understanding the interactions between anesthetic agents and nervous systems. Physiological-model-based general anesthesia monitoring and control can then be considered and optimized for each patient.