Background: The Eversense CGM System sensor is implanted in the upper arm. It uses a fluorescent, boronic acid glucose-binding moiety to measure glucose. The glucose indicator is susceptible to oxidative de-boronation from reactive oxygen species (ROS) in the interstitial fluid, necessitating daily calibrations. To reduce calibration frequency, a ROS indicator was added to measure oxidative de-boronation. Figure 1 (a) shows the copolymerization of glucose and ROS indicators into a single hydrogel matrix with orthogonal excitation emission properties. The sensor uses a 380 nm LED for excitation of the glucose indicator and a 470 nm LED for excitation of the ROS indicator.
Methods: The fluorescence of the indicators was characterized in vitro. In addition, sensors were implanted in subjects with type 1 diabetes in a 365-day clinical feasibility study to assess accuracy against fingerstick measurements.
Results: Figure 1 (b) illustrates the relationship whereby ROS exposure increases the fluorescence of the ROS indicator and decreases the fluorescence of the glucose indicator. A MARD of 9.9% against fingerstick with one calibration per week was observed through 90 days.
Conclusions: Early data suggests the multiple-analyte system should allow the next generation of long-term, implanted CGM systems to maintain accuracy with significantly reduced calibration requirements.
V.N.Velvadapu: None. J.M.Masciotti: Employee; Senseonics. A.D.Dehennis: Employee; Senseonics. P.Sanchez: Employee; Senseonics. K.S.Tweden: Employee; Senseonics. F.R.Kaufman: Consultant; Twin Health, Employee; Senseonics. S.Ioacara: Research Support; Senseonics.