Polarized Optical System for Noncontact Imaging of Epidermal Microcirculation Activities

Abstract

This study demonstrates the use of a polarized optical system for localized imaging of superficial tissue while removing multiple scattered lights by means of polarization gating. This study performed co-circular and cross-linear polarization experiments on the palm of the hand of thirteen Asian volunteers at resting and during arterial blood occlusion condition for the demonstration work. These co-circular and cross-linear polarized images were mathematically subtracted to remove the deeper backscattered lights. The resultant images were then processed using an algorithm written in MATLAB to calculate changes in the ratio of the color information of the polarization maintaining images, βGB, with different experimental condition. The results revealed an overall lower unitless βGB value of 1.12 ± 0.35 calculated for blood occlusion case compared to 1.73 ± 0.48 for at rest condition. The paired student's t-test revealed a strong correlation between βGB and the employed experimental methods that were hypothesized to modify one's blood oxygen level. This work has concluded that the developed system can potentially be used as an alternative means for noncontact localized imaging of superficial skin microcirculatory activities and may be used for wound evaluation and skin condition assessment.