Localized regulatory frequencies of human skin temperature derived from the analysis of series of infrared images

The physiological function of human skin in body temperature regulation is reviewed, and methods for measuring skin temperature are described. Different ways to extract diagnostic data from thermal images, focusing on dynamic studies that provide valuable information on the physiological and pathological functions of the autonomous nervous system, are presented. Using fast-Fourier-transform analysis, the frequencies of the different regulatory processes and their relative contributions to the overall temperature oscillations can be determined and used to assess the physiology and pathophysiology of the sympathetic nervous system. Preliminary studies have shown that one can distinguish between local and central processes by the spatial distribution of regulatory frequencies over a region of interest, such as the human back, by mild local cooling or by the effect of sleep on local thermal regulation