An Inpatient Performance Evaluation of a New Subcutaneous Glucose Sensor

The first generation Medtronic MiniMed Subcutaneous Glucose Sensor (Sof-Sensor) was originally approved by the FDA for commercialization as part of the Continuous Glucose Monitoring System (CGMS) on June 15, 1999 (PMA 980022). The Sensor is composed of a microelectrode with a thin coating of glucose oxidase beneath several layers of biocompatible membrane. This same sensor was used as part of subsequent continuous glucose monitoring (CGM) systems, such as the Guardian REAL-Time and Paradigm REAL-Time sensor augmented insulin pump. The current configuration of sensor has undergone in vitro and in vivo testing. A new second-generation glucose sensor (herein referred to as the Comfort Sensor) has been developed. The first-generation glucose sensor was approved with reported sensor accuracy (MAD) of 18%; it was labeled for a maximum use duration of 72 hours, using only the abdomen as an insertion site. The new sensor is shorter and has a smaller diameter, with a smaller gauge introducer needle. The new sensor inserter is designed to be used with the new sensor. The objectives of this study are to 1) Assess performance of the Comfort Sensor when used over a period of seven days with currently available devices, and 2) Assess performance of the Comfort Sensor when used over a period of seven days using new calibration algorithms (post-processed with algorithm for future devices). Accuracy data will be calculated based on comparing calibrated glucose sensor values to a "gold standard" (YSI plasma glucose values) in adult subjects during in-clinic testing, and on comparing calibrated glucose sensor values to glucose meter values during in-home testing. The devices that will be used for gathering sensor data during this study will be: 1) the Comfort Sensor, 2) the MiniLink (Transmitter), 3) the Guardian REAL-Time Display Device and 4) the CGMS iPro.