Background: A glucose-sensor incorporating multiple sensing elements may improve accuracy and reliability. Harmony (Medtronic) is a redundant electrochemical sensor with sensing elements on both planar surfaces. A diagnostic algorithm combines two sensing elements outputs to produce one robust and accurate sensor glucose value.

Aim: To evaluate the performance of Harmony.

Method: Twenty one adults with T1D wore two identical Harmony sensors continuously for 168 hours. On Day 4 and Day 8 post-sensor insertion, a standardised meal was eaten and venous samples  were collected for YSI plasma glucose measurements at 15 minute intervals for half-an-hour before and 3 hours post-meal. Between study visits, participants wore sensors in at home and performed capillary glucose testing 6-8 times daily. Sensor glucose values were processed prospectively and displayed only when trace characterisation algorithms deemed values to be sufficiently robust.  Sensor glucose readings were compared to plasma and capillary glucose levels.

Results:  The overall Mean absolute relative difference (MARD) was 10% during entire wear and 9% during the meal test period.  One hundred percent of sensor glucose values fell within zone A and B of the consensus error grid. Average sensor display time was higher in the combined-redundant sensor than each of the two sensing electrodes alone (97% versus 94%; p < 0.001). Average sensor survival was 6.8 days.

Conclusion: Performance of the Harmony sensor compares favourably with current generation glucose sensors.  Redundant electrochemical sensing technology is feasible, and potentially improves glucose-sensor reliability and accuracy which may facilitate artificial pancreas development.