Aspects of laser light scattering from skin tissue with application to laser Doppler blood flow measurement

Abstract

Studies of both intensity and Doppler shifted linewidths of light scattered from skin [human] tissue were made using photon correlation spectroscopy and optical fiber techniques. Measurements as a function of the separation of input and detecting fiber positions show characteristic features. These features are interpreted in terms of the positions of the scattering red blood cells and the tissue structure. Evidence is given for an interpretation of the differences in the scattered light for scattering from superficial vessels including capillary loops and from deeper lying larger vessels and shunts. Measurements using various laser wavelengths are discussed. The results of this study are important in the development of laser light scattering instruments for the measurement of peripheral blood flow and microcirculation.