On the choice of informative parameters of the spectrum of scattered radiation intensity fluctuations for evaluating the microhaemodynamics of human skin

The results are presented on investigations to determine the optimum and most sensitive to a change in the surface blood flow informative parameters of the spectrum of the dynamic speckle-field formed by the laser radiation scattered from the skin surface. It has been found that along with the value of change in the ratio of the spectral power density at high and low frequencies, the medium frequency of the spectrum, the spectrum asymmetry about the medium frequency and the ratio of the medium frequency to asymmetry strongly depend on the functional state of the skin and, consequently, on the state of luicrohaemodynamics in a given portion of the skin. Maps of the distribution of microcirculations in the investigated portion of the skin are given.