133-LB: Proof-of-Concept Study Results with a New Osmotic-Pressure–Based Continuous Glucose Sensor

Background: The Sencell sensor (Lifecare AS, Bergen, Norway) uses glucose induced changes in an osmotic pressure chamber for continuous measurement of glucose concentrations in the subcutaneous tissue. A close to linear correlation between the raw sensor signal and the glucose concentration and a very long duration of use (of up to 6-12 months or longer) are theoretically to be expected. The final device is planned to have the size of a grain of rice and to be implanted employing wireless energy and data transfer. Method: For a first clinical proof of concept study in humans, a wired version of the core sensing technology was embedded into a 4 mm needle and inserted into the abdominal subcutaneous tissue of healthy volunteers. The study was conducted to collect first human proof-of-concept performance data for algorithm development during meal experiments and for further device optimization. The raw data was analyzed after one-point calibration and minor trend correction in comparison to the Statstrip blood glucose meter and the Freestyle Libre 2 glucose sensor. Results: Seven participants (5 female, 2 male, age: 49±11 years) delivered a total of 105 direct comparator data-points (vs. Statstrip blood glucose meter) during repeated meal experiments with observation periods between 2 h and up to 72 days. The osmotic-pressure sensor followed glucose changes similar to the FreeStyle Libre device and reached an MARD of 9.8% in comparison to StatStrip (87 % and 13 % of the datapoints were lying in zones A and B of the consensus error grid, respectively). Conclusions: In this first human proof-of-concept study, the osmotic-pressure based continuous glucose sensor was shown to track s.c. glucose concentrations in a comparable manner as the Libre 2 needle sensor. The clinical performance characteristics of the first wired prototypes provide an encouraging perspective for the upcoming next development steps.