A calculation scheme and an algorithm to simultaneously diagnose several structural and biophysical parameters of skin
by reflected light are constructed in the paper. The procedure is based the fact that, after absorption and scattering, light
reflected by tissue contains information on its optically active chromophores and structure. The problem on isolating the
desired parameters is a spectroscopic one under multiple scattering conditions. The latter considerably complicates the
solution of the problem and requires the elaboration of an approach that is specific to the object studied. The procedure
presented in the paper is based on spectral tissue model properties proposed earlier and engineering methods for solving
the radiative transfer equation. The desired parameters are melanin and blood volume fractions, f and c, epidermis
thickness d, mean diameter D of capillaries, and blood oxygenation degree S. Spectral diffuse reflectance R(λ) of skin
over the range of 400 to 850 nm was calculated as a first stage. Then the sensitivity of R(λ) to the above parameters was
studied to optimize the algorithm by wavelengths and to propose an experimental scheme for diagnostics. It is shown
that blood volume fraction and f*d product can be rather surely determined by the reflected green -- red light. One can
find f and d separately as well as D by the blue reflectance. The last stage is the derivation of S at about 600 nm.
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