Observer-based closed-loop control of plasma glycemia

The paper investigates the problem of tracking a desired plasma glucose evolution by means of intra-venous insulin administration. A model-based approach is followed. Only measurements of glycemia are considered. A nonlinear observer for delay differential systems is used for the estimation of insulinemia. In the spirit of the separation theorem, a nonlinear control law is proposed, based on the feedback linearization, which makes use of the observer estimations instead of the full state measurements. The local convergence of the tracking error to zero is theoretically proved. In silico simulations, which also take into account input saturation, show the very good performance of the proposed control technique.