Intelligent control of glucose concentration based on an implantable insulin delivery system for type I diabetes

In this paper, the performance of a closed-loop Proportional-Integral-Derivative (PID) fuzzy logic controller (FLC) is evaluated as an automation scheme for an implantable insulin delivery system in type I diabetes therapy. The incredible progression in micro and nanotechnology has brought the concept of an “artificial pancreas” closer to reality. Manufacturing miniaturized, implantable insulin sensing and delivery devices are in fact feasible. The key to a successful implantable delivery system is the development of a self-regulated arrangement that mimics the performance of the real pancreas. The PID-FLC can be an effective control strategy for implantable insulin delivery system. It combines all the necessary components that react to the possible changes of glucose concentration in the blood stream. This paper is concerned with the parallel structure design of the PID-FLC which is achieved by combining the Proportional-Integral (PI-FLC) and Proportional-Derivative (PD-FLC) controllers. The PID-FLC is implemented on the nonlinear delay differential model of the glucose-insulin regulatory system, which describes how glucose and insulin interact in healthy individuals. Compared with other controlling approaches, the PID-FLC gives more than satisfactory results in maintaining near-normal glycemia and saving the amount of the daily delivered insulin.