Bulk Tissue Optical Parameters of Porcine Skin Dermis at 8 Wavelengths from 325 to 1557nm

摘要

Investigation of tissue optics requires accurate values of the bulk optical parameters: the scattering coefficient μ_s, absorption coefficient μ_a, anisotropy factor g and the real refractive index n_r. We employed a coherent reflectance curve method to determine the refractive index of fresh porcine skin dermis at 8 wavelengths between 325 and 1557nm. The surface profiles of fresh dermis samples were measured with a non-contact method of confocal imaging and the roughness parameters were extracted. To determine tissue optical parameters, a single integrating sphere was used to measure the diffused reflectance and transmittance with slab samples of fresh porcine skin dermis. Collimated transmittance was measured with the samples in situ using a spatial filtering setup. Based on these results, a Monte Carlo code capable of handling surface roughness of the tissue sample has been developed and used to inversely determine the bulk values of μ_s, μ_a and g at the 8 wavelengths which are significantly different from the reported values.