Refractive Index Anisotropy and Diffusion Rate in Cartilage Tissue

The paper presents the results of experimental and theoretical studies of cartilage tissue optical characteristics after the immersion impact and without it. We have found that the immersion effect leads to structural changes in the cartilage tissue, in particular, to the increased size of the scattering elements. The refractive index anisotropy of the cartilage tissue is measured in the samples subjected to immersion impact and without it. We demonstrate theoretically that the diffusion kinetics of the immersion fluid in the biotissue strongly depends upon the anisotropy of the diffusion rate along the collagen fibres and in the perpendicular direction. Due to the diffusion anisotropy, the increase of the mean rate of the immersion fluid diffusion in the biotissue can lead to the fall of light transmission through the sample rather than to its expected increase.