Measurements Of Optical Parameters Of Tissue Phantom

Accurate measurement of tissue optical parameters is a very important field in tissue optics, a basis for further research of light propagation within tissues, which can offer vital guidance to laser's clinic application such as laser surgery and laser dynamics. Measurement of tissue optical parameters being its key issue, the main work of this dissertation includes establishing of optical physical model of tissues, mathematics description of interaction between photons and biologic tissues, acquirement of optical parameters that are characteristic of tissues, emulation research on interaction between light and tissues, experimental design and analysis under lab conditions, and design principle and evaluation standard of measuring methods. To state specifically, the main content of this thesis contains as follows. 1) Diffuse reflectance approximation of photons within tissues is studied theoretically. 2) Monte Carlo Methods are introduced in details and applying this method research on interaction between photons and tissues is performed. 3) Single wavelength collimation transmittance experiment is designed and conducted, with total effective attenuation coefficient of tissue phantoms being obtained. 4) Also spatial resolved experiment used for measurement of light distribution of back-scattering light is designed and performed, which results in the acquirement of effective attenuation coefficient of tissue phantoms. Through combination of measured total attenuation coefficient and effective attenuation coefficient, we get optical parameters of measured samples. By contrast to according parameters calculated by MC methods and those in some literatures as well, it shows our results for optical parameters are creditable. The above work can establish a good basis for simulation measurement of multi-layer tissues and measurement of in-vivo and in-vitro tissues both theoretically and materially. 4) Due to the difference between experimental conditions and diffuse theory, in order to obtain a better result for optical parameters, preliminary research on inverse MC methods is done. Genetic algorithm is used to optimize our program and some certain effect is obtained, which can provide a favorable basis for further research.