Application of model reference adaptive control and modified Smith predictor to control blood glucose in type 1 diabetic patients

In this paper, a new adaptive control structure for time-delayed systems has been proposed, combining the model reference adaptive control with the modified Smith predictor (SP). Due to the extensive variability of the patients’ metabolism, an in silico clinical trial consisting of 30 patients is utilized to simulate the personal variability in the glucose control system. All the patients have random changes and sinusoidal oscillations in their parameters of the Dalla Man glucose-insulin model. Based on the quantitative and qualitative indicators, the performance of the proposed algorithm is compared to a PID controller of the Smith predictor structure. The results of the simulation show that the proposed control scheme is successful against the interpatient variation in fasting conditions, meal disruption rejection, and in terms of robustness. Insulin therapy often leads to high fluctuations in blood glucose and hypoglycemic events in patients with type 1 diabetes. On the other hand, a closed blood glucose loop control with an artificial pancreas can improve the patients’ quality of life. In this paper, the physiological behaviour of the system is modelled inversely using the daily patients’ data acquired by the GIM simulator.