The Accuracy Benefit of Multiple Amperometric Glucose Sensors in People With Type 1 Diabetes
- Jessica R. Castle, MD1⇓,
- Amy Pitts, RN1,
- Kathryn Hanavan, ANP-C1,
- Rhonda Muhly, BS1,
- Joseph El Youssef, MBBS1,
- Colleen Hughes-Karvetski, PHD2,
- Boris Kovatchev, PHD2 and
- W. Kenneth Ward, MD1
- 1Department of Medicine, Division of Endocrinology, Diabetes & Clinical Nutrition, Oregon Health & Science University, Portland, Oregon;
- 2Department of Psychiatry and Neurobehavioral Sciences and the Department of Systems and Information Engineering, Center for Diabetes Technology, University of Virginia, Charlottesville, Virginia.
- Corresponding author: Jessica R. Castle, .
OBJECTIVE To improve glucose sensor accuracy in subjects with type 1 diabetes by using multiple sensors and to assess whether the benefit of redundancy is affected by intersensor distance.
RESEARCH DESIGN AND METHODS Nineteen adults with type 1 diabetes wore four Dexcom SEVEN PLUS subcutaneous glucose sensors during two 9-h studies. One pair of sensors was worn on each side of the abdomen, with each sensor pair placed at a predetermined distance apart and 20 cm away from the opposite pair. Arterialized venous blood glucose levels were measured every 15 min, and sensor glucose values were recorded every 5 min. Sensors were calibrated once at the beginning of the study.
RESULTS The use of four sensors significantly reduced very large errors compared with one sensor (0.4 vs. 2.6% of errors ≥50% from reference glucose, P < 0.001) and also improved overall accuracy (mean absolute relative difference, 11.6 vs. 14.8%, P < 0.001). Using only two sensors also significantly improved very large errors and accuracy. Intersensor distance did not affect the function of sensor pairs.
CONCLUSIONS Sensor accuracy is significantly improved with the use of multiple sensors compared with the use of a single sensor. The benefit of redundancy is present even when sensors are positioned very closely together (7 mm). These findings are relevant to the design of an artificial pancreas device.
- Received October 4, 2011.
- Accepted December 11, 2011.
- © 2012 by the American Diabetes Association.
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