scholarly journals SystematicallyIn SilicoComparison of Unihormonal and Bihormonal Artificial Pancreas Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaoteng Gao ◽  
Huangjiang Ning ◽  
Youqing Wang
Keyword(s):  
Diabetes Mellitus ◽  
Closed Loop ◽  
Blood Glucose Concentration ◽  
Artificial Pancreas ◽  
Glucose Regulation ◽  
Closed Loop Control ◽  
Loop Control ◽  
Promising Direction ◽  
P Type

Automated closed-loop control of blood glucose concentration is a daily challenge for type 1 diabetes mellitus, where insulin and glucagon are two critical hormones for glucose regulation. According to whether glucagon is included, all artificial pancreas (AP) systems can be divided into two types: unihormonal AP (infuse only insulin) and bihormonal AP (infuse both insulin and glucagon). Even though the bihormonal AP is widely considered a promising direction, related studies are very scarce due to this system’s short research history. More importantly, there are few studies to compare these two kinds of AP systems fairly and systematically. In this paper, two switching rules, P-type and PD-type, were proposed to design the logic of orchestrates switching between insulin and glucagon subsystems, where the delivery rates of both insulin and glucagon were designed by using IMC-PID method. These proposed algorithms have been compared with an optimal unihormonal system on virtual type 1 diabetic subjects. Thein silicoresults demonstrate that the proposed bihormonal AP systems have outstanding superiorities in reducing the risk of hypoglycemia, smoothing the glucose level, and robustness with respect to insulin/glucagon sensitivity variations, compared with the optimal unihormonal AP system.

Closed-loop control for pediatric Type 1 diabetes mellitus

2015 ◽  
Vol 5 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Heather Wadams ◽  
Daniel R Cherñavvsky ◽  
Aida Lteif ◽  
Ananda Basu ◽  
Boris P Kovatchev ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Loop Control ◽  
Pediatric Type 1 Diabetes

scholarly journals Multinational Study of Subcutaneous Model-Predictive Closed-Loop Control in Type 1 Diabetes Mellitus: Summary of the Results

2010 ◽  
Vol 4 (6) ◽  
pp. 1374-1381 ◽  
Author(s):  
Boris Kovatchev ◽  
Claudio Cobelli ◽  
Eric Renard ◽  
Stacey Anderson ◽  
Marc Breton ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Multinational Study ◽  
Loop Control

scholarly journals Realizing a Closed-Loop (Artificial Pancreas) System for the Treatment of Type 1 Diabetes

2019 ◽  
Vol 40 (6) ◽  
pp. 1521-1546 ◽  
Author(s):  
Rayhan A Lal ◽  
Laya Ekhlaspour ◽  
Korey Hood ◽  
Bruce Buckingham
Keyword(s):  
Type 1 Diabetes ◽  
Glucose Control ◽  
Closed Loop ◽  
Diabetes Management ◽  
Artificial Pancreas ◽  
Loop System ◽  
Closed Loop Control ◽  
Closed Loop System ◽  
Loop Control

Abstract Recent, rapid changes in the treatment of type 1 diabetes have allowed for commercialization of an “artificial pancreas” that is better described as a closed-loop controller of insulin delivery. This review presents the current state of closed-loop control systems and expected future developments with a discussion of the human factor issues in allowing automation of glucose control. The goal of these systems is to minimize or prevent both short-term and long-term complications from diabetes and to decrease the daily burden of managing diabetes. The closed-loop systems are generally very effective and safe at night, have allowed for improved sleep, and have decreased the burden of diabetes management overnight. However, there are still significant barriers to achieving excellent daytime glucose control while simultaneously decreasing the burden of daytime diabetes management. These systems use a subcutaneous continuous glucose sensor, an algorithm that accounts for the current glucose and rate of change of the glucose, and the amount of insulin that has already been delivered to safely deliver insulin to control hyperglycemia, while minimizing the risk of hypoglycemia. The future challenge will be to allow for full closed-loop control with minimal burden on the patient during the day, alleviating meal announcements, carbohydrate counting, alerts, and maintenance. The human factors involved with interfacing with a closed-loop system and allowing the system to take control of diabetes management are significant. It is important to find a balance between enthusiasm and realistic expectations and experiences with the closed-loop system.

scholarly journals Closed-Loop Control During Intense Prolonged Outdoor Exercise in Adolescents With Type 1 Diabetes: The Artificial Pancreas Ski Study

Diabetes Care ◽  
2017 ◽  
Vol 40 (12) ◽  
pp. 1644-1650 ◽  
Author(s):  
Marc D. Breton ◽  
Daniel R. Cherñavvsky ◽  
Gregory P. Forlenza ◽  
Mark D. DeBoer ◽  
Jessica Robic ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Artificial Pancreas ◽  
Closed Loop Control ◽  
Loop Control

scholarly journals Closed-Loop Artificial Pancreas Using Subcutaneous Glucose Sensing and Insulin Delivery and a Model Predictive Control Algorithm: The Virginia Experience

2009 ◽  
Vol 3 (5) ◽  
pp. 1031-1038 ◽  
Author(s):  
William L. Clarke ◽  
Stacey Anderson ◽  
Marc Breton ◽  
Stephen Patek ◽  
Laurissa Kashmer ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Predictive Control ◽  
Insulin Infusion ◽  
Closed Loop ◽  
Artificial Pancreas ◽  
Open Loop ◽  
Closed Loop Control ◽  
Open Loop Control ◽  
Loop Control

Background: Recent progress in the development of clinically accurate continuous glucose monitors (CGMs), automated continuous insulin infusion pumps, and control algorithms for calculating insulin doses from CGM data have enabled the development of prototypes of subcutaneous closed-loop systems for controlling blood glucose (BG) levels in type 1 diabetes. The use of a new personalized model predictive control (MPC) algorithm to determine insulin doses to achieve and maintain BG levels between 70 and 140 mg/dl overnight and to control postprandial BG levels is presented. Methods: Eight adults with type 1 diabetes were studied twice, once using their personal open-loop systems to control BG overnight and for 4 h following a standardized meal and once using a closed-loop system that utilizes the MPC algorithm to control BG overnight and for 4 h following a standardized meal. Average BG levels, percentage of time within BG target of 70–140 mg/dl, number of hypoglycemia episodes, and postprandial BG excursions during both study periods were compared. Results: With closed-loop control, once BG levels achieved the target range (70–140 mg/dl), they remained within that range throughout the night in seven of the eight subjects. One subject developed a BG level of 65 mg/dl, which was signaled by the CGM trend analysis, and the MPC algorithm directed the discontinuance of the insulin infusion. The number of overnight hypoglycemic events was significantly reduced ( p = .011) with closed-loop control. Postprandial BG excursions were similar during closed-loop and open-loop control Conclusion: Model predictive closed-loop control of BG levels can be achieved overnight and following a standardized breakfast meal. This “artificial pancreas” controls BG levels as effectively as patient-directed open-loop control following a morning meal but is significantly superior to open-loop control in preventing overnight hypoglycemia.

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