1. Clinical Evaluation of an Automated Artificial Pancreas Using Zone-Model Predictive Control and Health Monitoring System
- Author
-
Harvey, Rebecca A, Dassau, Eyal, Bevier, Wendy C, Seborg, Dale E, Jovanovič, Lois, Doyle, Francis J, and Zisser, Howard C
- Subjects
Prevention ,Diabetes ,Bioengineering ,Autoimmune Disease ,Patient Safety ,Clinical Research ,Metabolic and endocrine ,Adult ,Algorithms ,Blood Glucose ,Blood Glucose Self-Monitoring ,Diabetes Mellitus ,Type 1 ,Female ,Humans ,Hypoglycemia ,Hypoglycemic Agents ,Insulin ,Insulin Infusion Systems ,Male ,Meals ,Middle Aged ,Monitoring ,Physiologic ,Pancreas ,Artificial ,Predictive Value of Tests ,Clinical Sciences ,Medical Physiology ,Endocrinology & Metabolism - Abstract
BackgroundThis study was performed to evaluate the safety and efficacy of a fully automated artificial pancreas using zone-model predictive control (zone-MPC) with the health monitoring system (HMS) during unannounced meals and overnight and exercise periods.Subjects and methodsA fully automated closed-loop artificial pancreas was evaluated in 12 subjects (eight women, four men) with type 1 diabetes (mean±SD age, 49.4±10.4 years; diabetes duration, 32.7±16.0 years; glycosylated hemoglobin, 7.3±1.2%). The zone-MPC controller used an a priori model that was initialized using the subject's total daily insulin. The controller was designed to keep glucose levels between 80 and 140 mg/dL. A hypoglycemia prediction algorithm, a module of the HMS, was used in conjunction with the zone controller to alert the user to consume carbohydrates if the glucose level was predicted to fall below 70 mg/dL in the next 15 min.ResultsThe average time spent in the 70-180 mg/dL range, measured by the YSI glucose and lactate analyzer (Yellow Springs Instruments, Yellow Springs, OH), was 80% for the entire session, 92% overnight from 12 a.m. to 7 a.m., and 69% and 61% for the 5-h period after dinner and breakfast, respectively. The time spent < 60 mg/dL for the entire session by YSI was 0%, with no safety events. The HMS sent appropriate warnings to prevent hypoglycemia via short and multimedia message services, at an average of 3.8 treatments per subject.ConclusionsThe combination of the zone-MPC controller and the HMS hypoglycemia prevention algorithm was able to safely regulate glucose in a tight range with no adverse events despite the challenges of unannounced meals and moderate exercise.
- Published
- 2014