Skin optical clearing is the method providing the increase of the depth and the contrast of non-invasive optical techniques. Dehydration is one of the possible mechanisms of optical clearing that may lead to reduce in both skin thickness and backscattering. However, the contribution of dehydration of skin to the collimated transmittance spectra is not studied in details. This paper presents the results of such study with rat skin ex vivo. Dehydration of skin sample was provided using a fan with a heater. Throughout the experiment, a warm air flux (~ 36 °C) was directed to the dermal side of each sample. Transmittance spectra were obtained using a system of two optical fibers equipped with collimators in the wavelength range of 400-800 nm. The thickness was measured during dehydration using a micrometer. As a result, it was found that a decrease in the thickness of the skin sample during dehydration led to an increased light transmission through the skin (an 11-fold increase at λ= 700 nm), and, at the same time, to an increase in the light attenuation coefficient μt due to an increase in the concentration of scatterers in the skin per unit volume.
|