The Multi-Sensor Distance Accuracy Study

An artificial pancreas system will likely require multiple glucose sensing elements to function safely. It is not yet known how close two glucose sensors can be placed and still work properly. Meaning, if one is reading inaccurately,and the other is positioned adjacent to it, will it read inaccurately also, defeating the purpose of having two sensors. Twenty adult subjects with Type 1 diabetes will wear four Medtronic REAL-Time glucose sensors during two separate 10-hour studies. The inter-sensor distances of each pair to be tested will be: 2, 10, 20, and 30mm apart. The sensors will be inserted the day prior to the study day to allow for signal stabilization and calibration. During the study day, arterialized venous blood will be drawn every 15 minutes to measure blood glucose. The sensor values and interstitial values will be recorded from each sensor receiver at each time point. Subjects will be fed two standardized meals and given pre-meal insulin based on their typical insulin to carbohydrate ratio.