Biological Optical Models And Monte Carlo Simulations For Prostate And Its Tumor

Being different from the traditional ultrasonic imaging and optical imaging, photoacoustic imaging combines the advantages of these two traditional imaging. It can use these advantages to overcome the defects of the two kinds of imaging, which is a promising imaging technology. This thesis is concerned with the preliminary study of the prostate and its tumor by photoacoustic imaging and photothermal therapy. Some progress has been made. There are the several points of innovations as follows.Firstly, this thesis created the optical model of prostate and its tumor, and finished the simulation of a light through the complex tissue by Monte Carlo method, the light energy distribution of tissue when the light is continue wave, and the various factors affecting the light energy distribution are discussed, such as absorption coefficient and scattering coefficient of prostate, absorption coefficient of its tumor, and completed the simulation of the optical transmission in the complex structure of tissue.Secondly, we use the optical model of prostate which is constructed into Monte Carlo simulation, and the light source is pulsed and cylindrical, then we can obtained the light energy distribution of prostate and tumor at different time, then using the relationship between photoacoustic signal and time domain light energy distribution, and simulate the relative value of photoacoustic signal. The simulation of photoacoustic signal can be used to predict the effects of the experiment, and then evaluate the feasibility of the experimental scheme.Thirdly, we use the prostate photoacoustic scanning system established by our lab to image of prostate sample by photoacoustic imaging, and verify the feasibility of prostate and tumor imaging using cylinder optical fiber, and some factors which influence the tumor of photoacoustic signal are discussed and researched.Fourth, we use the finite element analysis method to simulate the photothermal therapy of tumor, then get the tumor hyperthermia region at the different time. In addition, we discuss the hyperthermia effect by the influence of tissue size and initial temperature, and the cooling effect in the process of tumor hyperthermia were also discussed.