Observer-based glucose control via subcutaneous insulin administration

A closed-loop therapy for diabetic patients is proposed, by suitably exploiting a discrete Delay Differential Equation (DDE) model of the glucose-insulin system. To this aim, plasma glucose concentration is regulated by means of subcutaneous insulin administration, in order to track a desired glucose profile. The method of exact input/output feedback linearization and stabilization is used, in order to ensure the local convergence of the tracking error to zero. The use of a state observer for delay systems makes it so that the control law requires only glucose measurements, which are easily achievable according to the present technology. Even if exogenous insulin administration is standardly used for Type I diabetic patients (who do not have a pancreatic insulin release), the use of a DDE model allows to extend the proposed treatment also to Type II diabetes. Performed simulations show the effectiveness of the proposed approach.