Accurate Post-Calibration Predictions for Noninvasive Glucose Measurements in People Using Confocal Raman Spectroscopy

In diabetes prevention and care, invasiveness ofglucose measurement impedes efficient therapy and hampers theidentification of people at risk. Lack of calibration stability in noninvasive technology has confined the field to short-term proof ofprinciple. Addressing this challenge, we demonstrate the firstpractical use of a Raman-based and portable non-invasive glucosemonitoring device used for at least 15 days following calibration. Ina home-based clinical study involving 160 subjects with diabetes,the largest of its kind to our knowledge, we find that themeasurement accuracy is insensitive to age, sex, and skin color. Asubset of subjects with type 2 diabetes highlights promising real-liferesults with 99.8% of measurements within A + B zones in theconsensus error grid and a mean absolute relative difference of14.3%. By overcoming the problem of calibration stability, we remove the lingering uncertainty about the practical use of noninvasive glucose monitoring, boding a new, non-invasive era in diabetes monitoring.