Predictive Control with Variable Delays in Plasma Insulin Action for Artificial Pancreas

Abstract

Uncertain delays in the absorption, distribution, and utilization of insulin can cause model inconsistencies and poor glycemic control performance. To address this problem, an adaptive system identification approach able to handle the variable delays in the insulin pharmacokinetics is integrated in this work with a predictive control formulation to explicitly consider the plasma insulin concentration, which facilitates the designed controller to constrain the insulin concentration in the bloodstream. Adaptive models and the estimation of the insulin absorption and utilization rates improve the model predictions and control performance, and the efficacy of the proposed model predictive control algorithm handling the uncertain delays in insulin action is demonstrated using simulation case studies.