Comparative study of different control techniques for the regulation of blood glucose level in diabetic patients

Blood glucose regulation is of a great concern for insulin-dependant patients with excessive glucose in blood (hyperglycaemia), or low glucose profile (hypoglycaemia) due to excess insulin delivery. Both conditions can cause dangerous complications for diabetic patients, and hence glucose regulation in blood is of prime importance. Insulin pumps are used to deliver insulin in small quantities, allowing the glucose level to remain as close as possible to that of non-diabetics (near 100 mg dl(-1)). Different control techniques are used to maintain the glucose level and most of them depend on an exact mathematical or empirical model of insulin-glucose interaction. Recently, we have proposed different controllers that are based on fuzzy logic and so do not use mathematical modelling, which in general is nonlinear, complex and suffers from uncertainties. PI fuzzy controllers are physically related to classical PI and PID controllers, which are extremely popular. The parameter settings of classical and fuzzy logic controllers are based on deep common physical background. In this manuscript, a comparative study is proposed to evaluate the use of fuzzy logic controllers over other conventional controllers such as PI and PID controllers to maintain the blood glucose level within a normoglycaemic average especially when a diabetic patient is subjected to different conditions.