Publication

Abstract : As the diabetes mellitus is increasing day by day, a replacement for the conventional standard painful finger pricking technique is necessary. One of the main challenges for the accurate and precise non-invasive glucose monitoring is modeling the propagation effects when waves interact with the human tissues. As per literature, the infrared signals have the capability to detect glucose molecules more effectively than other signals in the electromagnetic spectrum. In this work, a phantom of the finger is created in ‘COMSOL — Multiphysics Simulator’ and the light tissue interactions in different spectroscopic ranges like near infrared (700−2500nm) and mid infrared (2500−25,000nm) are analyzed. The modeling of the finger is carried out by defining the different layers of finger which are stratum corneum, epidermis, papillary dermis, upper blood net dermis, reticular dermis, deep blood net dermis, fat, muscle and bone. The material properties like thickness, absorption coefficient, scattering coefficient and refractive index for each layer are analyzed separately. In both the mid-infrared and near-infrared ranges, the most glucose absorption was obviously noted in the upper blood net dermis. The second highest glucose absorption was observed in the deep blood net dermis followed by the papillary dermis. Interestingly, the stratum corneum had the largest scattering in the near-infrared and mid-infrared spectral ranges, followed by the papillary dermis. After completing the single layer analysis, the finger phantom as a whole, combining all the individual layers are analyzed. The results of absorption spectra and reflection spectra for both near infrared and mid infrared for the finger phantom are reported. Based on the modeling and results, it can be inferred that mid-infrared may exhibit the highest absorption.