Step 1-Calibration: During this step we plan to collect paired measurements of capillary blood glucose using reference method and data generated by the non invasive study device. Samples will be obtained at specific time points during 4 hours: at fasting, and after consuming standard liquid meal at 60, 120, 180 and 240 minutes. At each time point capillary blood glucose will be measured using the invasive reference method. The paired reference and study device data will be analyzed using multivariate regression model to formulate a calibration algorithm model. This model will convert the acetone values measured by study device to blood glucose values.