A Study On Noninvasive Measurement Of Tissue Optical Properties Based On Support Vector Method

Accurate measurement of tissue optical parametersis a very important field in tissue optics.Researches on the biological tissue optical properties are the precondition of light applications in the foundation research and clinical applications in medical fields,which can ofer vital guidance to laser's clinic application such as laser surgery and laser dynamics. The main work of this dissertation includes choosing exact optical physical model of tissues, mathematics description and simulation analysis of photons propagation in tissue, exploiting a new algorithm support vector machine (SVM) to solve the inverse problem of estimating the tissue optical properties from the diffuse reflectance profiles, and experimental design and analysis to evaluating the validity of the inverse algorithm and measuring methods.The main content of the dissertation involves:1. Firstly, The theoretical framework of tissue optics was described completely and systematically. Then, the optical parameters describing the reciprocity between light and tissues are distinct explanated and deduced for definitions. Next, we introduced the theories of light transport in the tissues Monte Carlo simulations and diffusion approximation theory.2. A two-layer model was builted to simulate the distribution of light in the tissue and generate spatially resolved reflectance data by Monte Carlo method. By using the Monte Carlo modeling for multi-layered tissues (MCML), the influences of different tissue optical properties on the diffuse reflectance profiles were analyzed and the statistical error of Monte Carlo method was discussed.3. The utilization of support vector machine (SVM) is characterized as a supervised learning algorithm capable of solving linear and non-linear problems. In this paper, we introduced this method into Tissue Optics field for the first time. We implemented the support vector classification(SVC) and support vector regression (SVR) algorithm by programming in C++ language. Then, we analyzed the unique corresponding relationship between the MC simulated diffuse reflectance data and the tissue optical properties in the case of single- and two-layer tissue models.4. Support Vector Regression was used to retrieve the tissue absorption and reduced scattering coefficients in the single- and two-layer tissue models, and the top layer thickness in two-layer model, from the steady-state spatially resolved diffuse...