Dynamic Thermography Derived Perfusion as a Potential Tool for Evaluating Cutaneous Perfusion Changes in Response to Low-level-laser Irradiation

Abstract

The objective of this study is to develop method for extracting cutaneous perfusion information from dynamic thermography, using an improved bio-heat transfer model for the initial application to study the responses of cutaneous perfusion to low level laser irradiation. The bio-heat transfer model developed in this study for dynamic thermography-derived perfusion employs the contributions of heat transfer due to blood circulation, which has been implemented in previous models, and a spatial Laplacian term accounting for heat changes due to conduction, which has been neglected by previous models. The model is applied to dynamic thermography imagery obtained at 23Hz of frame rate from cutaneous tissues of turtle subjects and human volunteers subjected to the same laser irradiation protocol of 20 seconds of irradiation between 20 seconds of idle time prior to and after the laser irradiation. The proposed method yields stable results over all 6 sets of human data with a perfusion range similar to that estimated from other cited works whereas the other models falter for 3 or more sets of data. For turtle data the perfusion pattern is similar to that by the other models attributable to the low changes in heat conduction pertaining to their thermoregulation mechanism. The algorithm is being implemented in a Graphical-User-Interface (GUI) for the clinical testing by physicians.