Accurate Non-Invasive Glucose Monitoring Based on Ph-Calibration

This work reports an accurate non-invasive glucose monitoring method based on pH-calibration. A pH-calibrated epidermal glucose monitoring device, which includes a pair of reverse iontophoresis (RI) electrodes, a glucose sensor and a pH sensor, is proposed. The RI electrodes are utilized to extract glucose from the interstitial fluid (ISF) by applying a mild current on the skin, facilitating subsequent glucose monitoring by the glucose sensor. The pH sensor is used to detect the real-time pH values of the extracted ISF. The changed pH indicates the variations of glucose extraction flux; therefore, a pH-calibration method is used to accordingly adjust the coefficient between the response current of the glucose sensor and blood glucose levels. Such pH-calibrated method and device could address the interference caused by pH fluctuations of the extracted ISF with the extraction time, the epidermal variations in different individuals and different areas of the same individual, making accurate non-invasive glucose monitoring.