Key points: Researchers exploited modern electronics to develop a new, less painful and noninvasive way to estimate blood glucose levels. Using an NIR sensor from a smartwatch, researchers linked metabolic index with blood glucose levels for the first time. Clinical tests on diabetic individuals are pending to confirm the applicability of the metabolic index in a real-world context. Blood glucose measurements (BGL) measurements typically involve drawing blood through a finger prick, but researchers want to leverage modern electronics to develop less painful an...