Designing Hybrid Controller for Blood Glucose

Abstract. Artificial pancreas is an alternative method instead of insulin treatment for patients with type 1 diabetes. Closed-loop control of blood glucose level (BGL) is one of the difficult problems in the field of biomedical engineering due to the dynamicity of time and the nonlinearity of the relationship between insulin and glucose, which is associated with time delay and model uncertainty. In this paper, we have proposed an integrated fuzzy-adaptive sliding mode control scheme for BGL tuning. Virtual patients described by mathematical models in MATLAB simulations have been used to evaluate the performance of the closed loop system in the presence of external disturbances, system time delay and patient-to-patient changes. System dynamics are determined online using fuzzy logic systems. The simulation results show the effective performance of the proposed control scheme of BGL regulation in the presence of simultaneous meals and physical movement disorders. The comparison of the proposed control method with the proportional-integral-derivative-derivative (PID) controller shows the superiority of the adaptive fuzzy integrated sliding mode controller with respect to the two common methods of BGL control and adjustment, namely PID and sliding mode. The results obtained by the control The proposer has demonstrated the effectiveness and robustness of the controller without the need for prior knowledge of T1DM patients. A remarkable feature of the closed-loop BGL regulator is that the controller can prevent hypoglycemia in patients with different physiological characteristics and adjust BGL to a normal level.