Robust regulation of blood glucose for Type-1 diabetes using insulin infusion limiter-based feedback control via artificial Pancreas

Abstract

This paper studies the feedback control of blood glucose concentration in Type-1 diabetes patients (T1DPs) through an artificial Pancreas via the glucose monitoring and insulin pump. For an artificial Pancreas, insulin infusion through a pump has been adapted by respecting the desired insulin infusion range for a patient. The insulin range has been incorporated by considering the lower and upper limits on the insulin infusion rate, which are maintained for a patient through the application of an asymmetric saturation nonlinearity (rate limiter). By incorporating the infusion rate range, the Bergman’s model of T1DPs via the saturated insulin input has been revised for attaining an improved model. To deal with the asymmetric saturation nonlinearity for positive systems, arising due to specific consideration of diabetes patients model, analytical investigations in terms of an inequality and signal transformation have been revealed. To control the glucose level and to keep the delivery of insulin within prescribed limits, a local feedback control strategy by application of the proposed analytical investigation of the nonlinearity has been provided. The proposed automatic control approach is more safe for a T1DP than the existing methods due to consideration of the desired insulin rate limits and positive input. In addition, a robust regulation strategy against variation in the glucose level, caused by the food intake, has also been provided in terms of linear matrix inequalities. The attained results can be applied for manufacturing a better device for the purpose of blood glucose regulation in T1DPs. A comparative simulation study to demonstrate the superiority of the proposed scheme has been provided at the end.