Clinical validation of noninvasive blood glucose measurements by midinfrared spectroscopy.

BACKGROUND: Non-invasive glucose monitoring (NIGM) is considered the holy grail of diabetes technology. Currently, diabetes is predominantly managed based on finger pricking and analysis of a drop of blood with test strips fitting into a glucometer. This invasive, painful and uncomfortable procedure is one of the reasons for insufficient diabetes management. Sensors for continuous glucose monitoring (CGM) in interstitial fluid (ISF) using a subcutaneous microscopic filament present a minimally invasive alternative. Worldwide, there is intense research and development for a true non-invasive glucose measurement. METHODS: DiaMonTech has demonstrated a NIGM technology that targets glucose in ISF. An infrared beam from a quantum cascade laser excites glucose molecules at wavelengths between 8 and 12 µm, where glucose has specific fingerprint absorbance. Absorption results in a small amount of heat in the skin, which can be detected on the surface using a photothermal deflection technique. This procedure is painless, harmless, and does not require consumables. RESULTS: We report here a single-center clinical test with 36 individuals (clinicaltrials.gov ID: NCT06088615). The accuracy of the NIGM device was evaluated in two subsequent sessions per individual, with different amounts of calibration data. Four different algorithms were tested for data analysis. The accuracy for the best algorithm, expressed as Mean Absolute Relative Difference was 20.7 % and 19.6 % for the two sessions. CONCLUSIONS: This is equivalent to the performance of early CGM systems cleared by the FDA for adjunctive use by people with diabetes. It demonstrates that glucose can be reliably measured with this non-invasive technology and opens new perspectives for a better management of diabetes.