title: Early Detection of Physical Activity for People With Type 1 Diabetes Mellitus.
abstract: BACKGROUND
  Early detection of exercise in individuals with type 1 diabetes mellitus (T1DM) may allow changes in therapy to prevent hypoglycemia. Currently there is limited experience with automated methods that detect the onset and end of exercise in this population. We sought to develop a novel method to quickly and reliably detect the onset and end of exercise in these individuals before significant changes in blood glucose (BG) occur.
  
  
  METHODS
  Sixteen adults with T1DM were studied as outpatients using a diary, accelerometer, heart rate monitor, and continuous glucose monitor for 2 days. These data were used to develop a principal component analysis based exercise detection method. Subjects also performed 60 and 30 minute exercise sessions at 30% and 50% predicted heart rate reserve (HRR), respectively. The detection method was applied to the exercise sessions to determine how quickly the detection of start and end of exercise occurred relative to change in BG.
  
  
  RESULTS
  Mild 30% HRR and moderate 50% HRR exercise onset was identified in 6 ± 3 and 5 ± 2 (mean ± SD) minutes, while completion was detected in 3 ± 8 and 6 ± 5 minutes, respectively. BG change from start of exercise to detection time was 1 ± 6 and -1 ± 3 mg/dL, and, from the end of exercise to detection time was 6 ± 4 and -17 ± 13 mg/dL, respectively, for the 2 exercise sessions. False positive and negative ratios were 4 ± 2% and 21 ± 22%.
  
  
  CONCLUSIONS
  The novel method for exercise detection identified the onset and end of exercise in approximately 5 minutes, with an average BG change of only -6 mg/dL.
authors.affiliation: Department of Chemical Engineering, University of California, Santa Barbara, CA, USA William Sansum Diabetes Center, Santa Barbara, CA, USA The first 2 authors contributed equally to this study.
authors.forename: Isuru S
authors.initials: IS
authors.lastname: Dasanayake
authors.affiliation: William Sansum Diabetes Center, Santa Barbara, CA, USA The first 2 authors contributed equally to this study.
authors.forename: Wendy C
authors.initials: WC
authors.lastname: Bevier
authors.affiliation: William Sansum Diabetes Center, Santa Barbara, CA, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Castorino
authors.affiliation: William Sansum Diabetes Center, Santa Barbara, CA, USA.
authors.forename: Jordan E
authors.initials: JE
authors.lastname: Pinsker
authors.affiliation: Department of Chemical Engineering, University of California, Santa Barbara, CA, USA William Sansum Diabetes Center, Santa Barbara, CA, USA.
authors.forename: Dale E
authors.initials: DE
authors.lastname: Seborg
authors.affiliation: Department of Chemical Engineering, University of California, Santa Barbara, CA, USA William Sansum Diabetes Center, Santa Barbara, CA, USA.
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Doyle
authors.affiliation: Department of Chemical Engineering, University of California, Santa Barbara, CA, USA William Sansum Diabetes Center, Santa Barbara, CA, USA dassau@engineering.ucsb.edu.
authors.forename: Eyal
authors.initials: E
authors.lastname: Dassau
mesh_terms: D056044:Actigraphy / Q000295:instrumentation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001331:Automation; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015190:Blood Glucose Self-Monitoring; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D042241:Early Diagnosis; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis / Q000517:prevention & control; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000009:adverse effects; D007332:Insulin Infusion Systems; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D019397:Pancreas, Artificial; D011237:Predictive Value of Tests; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007004:Hypoglycemic Agents
keywords: accelerometry; artificial pancreas; exercise; physical activity; type 1 diabetes mellitus