Method for measuring the optical properties of bio-materials utilizing the polarized light system for diagnosis and monitoring of diabetes

Abstract

Recently, the study of optical parameters on biological samples has attracted more and more attention from researchers because of the great potential in noninvasive practical applications. In this study, an analytical technique based on the Stokes polarization and the Mueller matrix decomposition method was used to extract the optical properties of human plasma samples (i.e. linear birefringence (LB), linear dichroism (LD), circular birefringence (CB), circular dichroism (CD), linear depolarization (LDep), and circular depolarization (CDep)). The optical experimental system was set up to measure and analyze the optical parameters of human blood plasma samples containing dissolved D-glucose with concentrations ranging from 0~1 M. The results showed that there was a good agreement between CB property and D-glucose concentration in human blood plasma samples and in phantom tissue samples containing a 1.4 μm polystyrene microsphere. For the human blood plasma, CB property increased linearly with the concentration of D-glucose whereas the depolarization index decreased slightly as the concentration of D-glucose increased. The proposed optical method has the advantages of not only extracting the optical parameters of the biological samples but also maintaining the accuracy by decoupling method for the optical parameters of the samples, thereby reducing the effect on measurement results. Therefore, this approach has promising applications in non-invasive diabetic diagnosis and monitoring by the optical method.