Artificial pancreas: glycemic control strategies for avoiding hypoglycemia

Abstract

This paper examines the performance of two new closed-loop control strategies developed as part of the Artificial Pancreas project, this being the most promising treatment for type 1 diabetes mellitus. The first strategy uses a new version of the well-known proportional, integral and derivative control, developed to respect state and input positivity constraints. The second is a new formulation of model-based predictive control with an impulsive input. The strategies’ performance is evaluated with 50 virtual patients taken from the literature and the UVa/Padova metabolic simulator, approved by the US Food and Drug Administration. Also, a robustness analysis is added to evaluate the strategies under the parametric variations of the most important physiological parameters. The results show that both strategies have a good performance with low to moderate plant-model mismatch.

Observer‐based control for plasma glucose regulation in type 1 diabetes mellitus patients with unknown input delay

“…8,9 An AP is an insulin pump driven by a control algorithm that regulates glucose levels, emulating the natural pancreas functions. 10 The advantage of AP over manual insulin introduction is that the patient will have his glucose levels constantly controlled without being severely affected by his activities, such as unplanned meals, exercise, or stress. 11 The development of APs has generated interest in the scientific community, where different models have been formulated to avoid hypoglycemia and hyperglycemia 10 ; personalized model-based algorithms for patients with different insulin responses 12 ; algorithms for detection and classification for different types of diabetes [13][14][15] ; optimal state feedback controllers with a Kalman filter designed to minimize the elevated glucose levels, 16 among others.…”

“…10 The advantage of AP over manual insulin introduction is that the patient will have his glucose levels constantly controlled without being severely affected by his activities, such as unplanned meals, exercise, or stress. 11 The development of APs has generated interest in the scientific community, where different models have been formulated to avoid hypoglycemia and hyperglycemia 10 ; personalized model-based algorithms for patients with different insulin responses 12 ; algorithms for detection and classification for different types of diabetes [13][14][15] ; optimal state feedback controllers with a Kalman filter designed to minimize the elevated glucose levels, 16 among others. The Bergman minimal model (BMM) has been popular since it is a simple nonlinear glucose-insulin model that considers physiological parameters such as glucose efficiency, insulin sensitivity, and insulin degradation.…”

“…One of the significant advances for the T1DM treatment was the development of a mechanism that can replicate the pancreas's normal behavior; this mechanism is known as Artificial Pancreas (AP) 8,9 . An AP is an insulin pump driven by a control algorithm that regulates glucose levels, emulating the natural pancreas functions 10 . The advantage of AP over manual insulin introduction is that the patient will have his glucose levels constantly controlled without being severely affected by his activities, such as unplanned meals, exercise, or stress 11 …”