A Feasibility Study of a Novel Glucose Sensor for Continuous Glucose Monitoring in Type 1 Diabetes.

The Harmony Sensor represents an advance in electro-chemical sensor design and incorporates a redundant sensor system. Redundancy can be defined as two or more sensing elements utilizing the same or different technologies to measure the same output. The Harmony sensor consists of a unique electro-chemical sensor in a fold-over design, so that there are sensing elements on both planar surfaces. This feasibility study will assess the accuracy and reliability of the redundant electrochemical sensor (Harmony) for Contiuous Glucose Monitoring (CGM) compared to current non-redundant electrochemical sensors. All participants will continuously wear two investigational Harmony glucose sensors for the whole duration of the study (168 hours). Each sensor will be inserted subcutaneously into the abdomen using a dedicated sensor inserter, a procedure which takes under 5 minutes. Both sensors are attached to a glucose sensor recorder or transmitter which will capture all sensor related information and be uploaded at the conclusion of the study. The participant will follow the following schedule: Visit 1 (Day 1): Both sensors will be inserted. Devise training will be provided to the participants. Finger-prick capillary glucose will be performed via study glucose meter at 30 minute intervals for half-an-hour prior to and 3 hours post sensor insertion (first 15 participants), and at 30 minute intervals from half-an-hour to 3 hours post sensor insertion (last 15 participants). Visit 2 (Day 4): 72 hours post insertion of the sensors, participants will return to clinical trial centre (CTC) to perform a meal test. A standardised test meal containing 65g carbohydrate will be consumed by each participant. Venous blood samples will be collected at 15 minute intervals for half-an-hour prior to and 3 hours post meal ingestion, to be used for glucose measurement by YSI and study glucose meter. Visit 3 (Day 8): 168 hours post insertion of the sensors, participants will return CTC to perform a final meal test. A standardised test meal containing 65g carbohydrate will be consumed by each participant. Venous blood samples will be collected at 15 minute intervals for half-an-hour prior to and 3 hours post meal ingestion, to be used for glucose measurement by YSI and study glucose meter. Between the visits, participants will be instructed to perform finger-prick glucose levels a minimum of 8 times a day (pre-meals and 2 hours post meals) which wil be recorded on the study glucose meter history. Data from study devices will not impact upon decisions involving care of the participants as sensor generated glucose data will not be available to the participants.