A Variable State Dimension Approach to Meal Detection and Meal Size Estimation: In Silico Evaluation Through Basal-Bolus Insulin Therapy for Type 1 Diabetes

IEEE Trans Biomed Eng. 2017 Jun;64(6):1249-1260. doi: 10.1109/TBME.2016.2599073.

Abstract

Objective: This paper aims to develop an algorithm that can detect unannounced meals and estimate meal sizes to achieve a robust glucose control.

Methods: A variable state dimension (VSD) algorithm is developed to detect unannounced meals and estimate meal sizes, where a Kalman filter operates on a quiescent state model when no meal is detected, and switches to a maneuvering state model to estimate meal information once the meal-induced glucose variability is statistically significant.

Results: Through evaluation using 30 subjects of the UVa/Padova simulator, a basal-bolus (BB) control using the VSD-estimated meal size for each meal can achieve mean blood glucose (BG) of 142 mg/dl with an average 17.7% of time in hypoglycemia. In terms of 20 Monte-Carlo simulations for each subject over a two-day scenario, where each meal/snack has a probability of 0.5 not to be announced, the BB control using VSD for unannounced meals can achieve an average mean BG of 143 mg/dl with 8% of time in hypoglycemia, in contrast to mean BG of 180 mg/dl with 8% of time in hypoglycemia obtained by BB with missing boluses. Additionally, VSD is able to detect a meal within 45 (±14) min since its start with a 76% success rate and 16% false alarm rate.

Conclusion: The addition of VSD to the BB control improves glucose control when meal announcements are missed.

Significance: The VSD can be used as a complementary tool to detect meal and estimate meal size in absence of a meal announcement.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Algorithms
  • Blood Glucose / metabolism*
  • Computer Simulation
  • Diabetes Mellitus, Type 1 / drug therapy*
  • Diabetes Mellitus, Type 1 / physiopathology*
  • Drug Therapy, Computer-Assisted / methods*
  • Feedback, Physiological
  • Feeding Behavior
  • Food Analysis / methods
  • Humans
  • Hypoglycemic Agents / administration & dosage
  • Insulin / administration & dosage*
  • Meals / classification*
  • Models, Biological*
  • Postprandial Period

Substances

  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin