Online autocalibration of a PID controller of neuromuscular blockade

A digital PID controller incorporating several modifications to accommodate the characteristics of neuromuscular blockade is described. The control system was evaluated in 30 patients. Subsequent analysis of the data collected during surgery indicates that the variability of the patient responses is much wider than that inferred from the literature. The paper presents an improved empirical model for the pharmacodynamic response to atracurium. Supported on this model, and based on statistical regression techniques, a method for the online tuning of the digital PID controller to the patient's individual dynamics is presented.