Clinical validation of noninvasive blood glucose measurements by midinfrared spectroscopy

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. 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. 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. 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. Kaluza et al. present a clinical evaluation of a noninvasive glucose measuring system based on infrared excitation of glucose in skin and photothermal detection at the skin surface. The results demonstrate an accuracy comparable to early minimally invasive glucometers and could improve diabetes management. People with diabetes cannot regulate the amount of a sugar called glucose in their blood. They need to regularly check the amount of glucose in their blood so they can take treatments that adjust the levels. This procedure is painful and uncomfortable as it involves pricking the skin to make it bleed. We used an infrared laser that enables a painless determination of the amount of glucose present in skin. Our device was tested in 36 people with and without diabetes and showed an accuracy similar to other glucose monitors approved by the US food and drug administration (FDA). Our method could make blood glucose checks easier and more comfortable in the future and improve diabetes management.