Light Transport for Medical Laser Treatments

摘要

The subject of the thesis is theoretical dosimetry of laser light in biological tissues. The predicted light doses are evaluated to optimize the parameters of the laser beam for a specific treatment, or to investigate the feasibility of a new diagnostic method. Only stationary problems are treated. The sources are continuous wave laser beams (or long pulses). The aim of the research described in the thesis is to calculate stationary light doses in laser/tissue geometries that are two or three dimensional. In chapter 2 the basic equation of tissue optics is discussed: the equation of transfer. Boundary conditions to that equation are derived for the different interfaces that occur. In section 2.4 an overview is given of the main methods to approximate the solution to the equation of transfer in a two- or three-dimensional geometry. Chapters 3 and 4 concern two of these solution methods: the Monte Carlo method and the diffusion approximation. In Chapter 5 the authors give the results of an application of the last method.