Visualization Technique for Water Content Distribution of Skin Tissue by Dualband Polarization Imaging

The advanced imaging technique for visualizing two-dimensional water content distribution in the stratum corneum of human skin is proposed. The method involves two elemental principles of spectral filtering and imaging with polarization control. It is found in the in vivo experiment in the visible and the near-infrared range that the reflectance spectra of skin tissue in the wavelength range shorter than 600 nm are affected largely by water content. The polarization imaging technique is, on the other hand, introduced for emphasizing the subsurface reflection from skin tissue. The superficial reflection can be separated from the deeply penetrated light by controlling the orientations of the polarizer and the analyzing polarizer put in front of the light source and the imaging device, respectively. The combination of spectral bandpass filtering and polarization imaging enables us to acquire the water content distribution of the stratum corneum