Luenberger-Like Observers for Nonlinear Time-Delay Systems with Application to the Artificial Pancreas: The Attainment of Good Performance

The aim of this article is to show the good performance obtained by the state observer applied to a delay differential equations (DDE) model of the glucose-insulin system recently used in the artificial pancreas (AP) framework. Validation is carried out by real clinical measurements available from 20 healthy subjects who underwent an intravenous glucose tolerance test (IVGTT). The results show that the observer behavior is robust with respect to the initial conditions, which have been set according to a pair of very critical cases of under- and overestimation. Also, the robustness of the observer with respect to some model parameters, such as the delay in the pancreatic insulin production, is discussed.