Detection and analysis of temperature-sensitive dermal blood perfusion dynamics and distribution by a hybrid camera system

In this paper we present an application of two optical imaging modalities for non-invasive assessment of dermal perfusion. This hybrid setup consists of a photo-plethysmographic camera sensing in the visible spectrum and a thermal camera sensing in the infrared-C-band. This allows to combine the information of both sources complementarily: The extracted perfusion index as well as the skin surface temperature. The feasibility of the presented system is tested in two studies with local temperature stress on the forehead of a subject. In the first, a local cooling on the subject´s forehead is monitored and further analyzed. In the second, skin perfusion reactions to heat are considered. For both experiments the results are compared to baseline measurements and non-affected areas in the field of view of the cameras. As results, the dependencies between temperature and perfusion change are presented. Further, influences of the stressor can be visualized in functional mappings of calculated perfusion indices. For the performed test, a linear correlation between temperature and perfusion change is obtained.