<title>Sampling volume produced by shallow optical probes in skin reflectance measurements</title>

Abstract

The absolute quantified measurement of hemoglobin skin blood saturation from collected reflectance spectra of the skin is complicated by the fact that the blood content of tissues can vary both in the spatial distribution and in the amount. These measurements require an understanding of which vascular bed is primarily responsible for the detected signal. Knowing the spatial detector depth sensitivity makes it possible to find the best range of different probe geometries for the measurements of signal from the required zones and group of vessels inside the skin. To facilitate this we have developed a Monte Carlo simulation to estimate the sampling volume offered by fiber-optic probes with a small source detector spacing, and by the confocal probe. The optical properties of the modeled medium were taken to be optical properties of the Caucasian type of skin tissues in the visible range of the spectrum. The authors propose this simple numerical methods as a tool for the probes examination to yield measurements which are preferentially sensitive to blood at different depths within the skin.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.