Automated Feedback Based Insulin Regulatory System for Diabetic Patients

Abstract

For patients with diabetes especially for Type-I, a.k.a. insulin dependent diabetes, tight control of glucose level is essential. Regulating blood glucose concentration using the insulin infusion device is important for these patients, because they have deficiency of insulin production by pancreas that prevents appropriate metabolism of glucose. This paper is focused to envisage the regulation and management of the concentration of glucose and insulin in the blood of a diabetic. Using this model, a Feedback-loop in a system that regulates and manages the blood glucose-insulin has been designed, implemented and analyzed using Matlab. Keywords: Insulin, Glucose, Diabetes, Type 1. I. Introduction Insulin, a hormone released from the pancreas, controls the amount of sugar in the blood. When people eat or drink, it is broken down into materials, including the simple sugar glucose, that the body needs to function. Sugar is absorbed into the bloodstream and stimulates the pancreas to produce insulin. Insulin allows sugar to move from the blood into the cells. Once inside the cells, it is converted to energy, which is either used immediately or stored as fat or glycogen until it is needed. If the body does not produce enough insulin to move the sugar into the cells, the resulting high levels of sugar in the blood and the inadequate amount of sugar in the cells together produce the symptoms and complications of diabetes. For patients with diabetes especially for Type-I, insulin dependent diabetes, tight control of glucose level is essential. Regulating blood glucose concentration using the insulin infusion device is important for these patients, because they have deficiency of insulin production by pancreas that prevents appropriate metabolism of glucose. Many patients, who take insulin infusion in their diabetes therapy, inject insulin with needles and syringes that deliver insulin just under the skin, so that the functions of the pancreas are replaced by some external devices. An external insulin pump is an electro-medical device that delivers insulin through narrow and flexible plastic tubing that ends with a needle inserted just under the skin near the abdomen. The pump releases doses of insulin at meals and during the periods when blood glucose is too high based on measured values of glucose sensors (1). A patient's glucose concentration may change dynamically depending mostly on his /her physical activities and nutrition, and therefore, the amount of insulin needed varies from time to time. A number of diseases may occur, possibly resulting in life-threatening health conditions if the supply of insulin is not in time or not correctly dosed or fails for some reasons. For example, sustained hyperglycemia (blood glucose exceeding 120 mg/dL) may lead to most of the long-term complications associated with diabetes, such as nephropathy and retinopathy.