Control Systems for Artificial Pancreas Use During and After Exercise
Dates: 9/30/13 – 6/30/18
Co-Investigators: Laurie Quinn, Joan Briller, Lisa Sharp
Abstract: To date, a limited number of research groups have been able to demonstrate that blood glucose homeostasis can be maintained in patients with Type 1 Diabetes Mellitus (T1DM) by the implementation of an “artificial pancreas” (AP). Few research groups have attempted to test their AP technologies in an environment of exercise. Research on the development of AP systems that can control blood glucose (BG) levels during the physical activities of patients with T1DM is important for three reasons. Firstly, many patients with T1DM use daily physical activity as an important element of regulating their BG concentrations. Secondly, a large fraction of patients with T1DM participate in individual and/or group sports that dramatically change glucose turnover rates. This patient population would be well served by an AP that functions properly during their sportive activities. Thirdly, the activity patterns in several sports with bursts of high-intensity efforts are similar to children’s plays and the AP system developed in the proposed work will more conductive to the carefree play of children. An AP with properly developed control and hypoglycemia early warning systems will be safe and effective to use both during and after a variety of types of exercise for patients with T1DM. This technology will dramatically reduce the number and duration of hypoglycemia episodes as compared to conventional therapy (CSII or MDI). Such AP systems can only be developed by using a sophisticated multivariable approach that includes glucose concentrations (the dependent variable) and a number of other physiological variables that impact glucose homeostasis (i.e. insulin levels, energy expenditure, etc.). Our multivariable adaptive control framework provides the proper setting to achieve APs that are effective during and after a number of types of physical activities that differ markedly in energy expenditures and the metabolic systems used to support that expenditure (i.e. aerobic, anaerobic, mixed activities). The specific aims of this study are: (1) Development of a multivariable simulation system that describes the effects of different types of exercise on variations in blood glucose concentration; (2) Development of multivariable control and hypoglycemia early warning systems that will be safe to use during and after various types of exercise for patients with T1D; (4) Development of multivariable control and hypoglycemia early warning systems that will be safe to use during and after various types of group sports and children’s plays. The focus will be on sports with bursts of high-intensity efforts; and (5) Testing of the AP system in CRC and diabetes sports camps.