NON-INVASIVE BLOOD GLUCOSE MONITORING OF 95% CERTAINTY BY PRESSURE REGULATED MID-IR

Abstract

To fight against diabetes mellitus, a chronicle metabolic disease, from which more than 400 million people suffer in the world, the patients have to puncture their fingers 4-5 times a day when using a glucometer for the blood glucose level checks, causing invasive pain and the risk of infection. Therefore, the non-invasive method has been urged for blood glucose monitoring, among which the mid-infrared spectroscopy (Mid-IR) response of interstitial fluid was found to be promising. However, despite the prolonged effort, the accuracy still falls well below the FDA’s requirement. To break this barrier which lasted for almost three decades, we discovered the finger contact pressure playing a critical role during the measurement, where the Mid-IR reading could be affected significantly by a small change of the finger posture. In addition, the Mid-IR absorption level was also found to be highly associated with individuals, revealing the necessity of adjusting the calibration correlation for each patient. By imposing a certain contact pressure monitored by a pressure transducer, we were able to achieve over 95% certainty from the Mid-IR measurement of glucose concentration and 100% comparability to the “true” glucose concentration for the first time. This significant enhancement of the accuracy was found to be mainly attributed to the fact that, the finger tissue undergoes certain morphological change because of the pressure, where much more interstitial fluid becomes accessible by the Mid-IR detector.