Determination of optical properties of human tissues obtained from parotidectomy in the spectral range of 250 to 800 nm

Abstract

The absorption coefficient μa and scattering coefficient μ´s of different tissue types obtained during parotidectomy are determined in the wavelength range of 250 nm to 800 nm. These values are obtained by high precision integrating sphere measurements in combination with an optimized inverse Monte Carlo simulation (iMCS). To conserve the optical behavior of living tissues, the optical spectroscopy measurements are performed directly after tissue removal. This study includes fresh samples of the ear, nose and throat (ENT) region, as muscle tissue, nervous tissue, white adipose tissue, stromal tissue and parotid gland of five patients. The measured behavior of adipose corresponds well to the literature, which sustains the applied method. It is shown, that muscle is well supplied with blood as it features the same characteristic peaks at 430 nm and 555 nm in the absorption curve. The parameter μ´s decreases for all tissues type above 570 nm. The accuracy is adequate for the purposes of providing μa and μ´s of different human tissue types as muscle, fat or gland tissue, which are embedded in large complex structures such as in the ENT area. It is therefore possible for the first time to present reasonable results for the optical behavior of human soft tissue located in the ENT area and in the near-UV, visual and near-IR areas.