抄録
We describe a light scattering methodology that could facilitate a non-invasive, in vivo measurement of the thickness of stratum corneum in skin, as well as other physical observables. Namely, the in vivo method could well be based on the detailed observations of the scattered photons emitted at the surface of skin, as a laser beam focused on the surface propagates within. Preliminary in vitro investigations using this methodology on pig skin indicate that it is possible to distinguish the boundary between the stratum corneum (SC) and the Malphigian layer (ML), via the measured intensity of photons emitted at the surface but along the expected trajectory of the laser beam within the skin. The thickness of the SC could then be calculated from the measured distance between the skin surface and the SC/ML boundary, if also the angle of trajectory of the transmitted light is known (Snell's law). Since this angle is dependent on the unknown refractive index of SC, further measurements at different incident angles were necessary to determine the SC thickness and refractive index. Based on the results of our preliminary studies, it is reasonable to predict that light scattering methodologies could be useful for cosmetic industry.
