Research On The Computer Simulation Of Photodynamic Therapy

Photodynamic therapy (PDT) is the developing medical treatment technique which kills and wounds tumour and another hyperplasia tissue to achieve treatment aim via photoconductive action of biology. Experiment studying has discovered that in the premise of certain concentration of the photosensitizer absorbed by tissue, the higher radiation intensity, the more powerful photosensitizer formed oxidation capacity, and the area will have a stronger anti-organizational effectiveness. So understanding and mastering the action rules of laser and myocardium tissues, looking for a effective approach to increase radiation intensity at all parts of the tumour have significant meaning to the clinical applicationof PDT. Otherwise, in PDT process, the laser exposure for the tissue will also have a certain heat treatment effect, so researching and mastering the connection between temperature damage and tissue parameter have significant meaning to enhance effect of ancillary heat treatment, and have certain reference value for biomedical and tissue optical research.The paper has established the theoretical model according to the principle of PDE and ancillary heat treatment, and it has studied the action rule between laser and tumour utilizing finite element means. Firstly, the principles and rules of finite element means are explained detailedly. This paper has also studied and discussed the infection of laser photons transmission and distribution in tumour made by absorption coefficient μ_a and scattering coefficient μ_s, the infection of temperature distribution in tumor made by tissue heat parameter, the infection of photon and temperature distribution made by the place and amount of light fibre using MATLAB as the platform, and has done the relevant quantitative calculation to sphaeroid tumor organization. At the base of thses,it has developed the tumor model and done the relevant quantitative calculation to light distribution measurement and the temperature distributed value of ellipsoid tumor organization under different conditions. It has made a conclusion that in order to guaranteed simultaneously the actinic effect and the thermotherapy effect,we should lay aside two optical fibers symmetrily to illuminate in its major axis regarding the center for a ellipsoid tumor organization of which major axis is 2.0cm and minor axis is the 1.2cm, and the distance of two optical fibers should control be 0.8 ~ 1.0cm. The expansion oftumour models makes finite element means can simulate the photochemical effect and heat effect in treatments of different shape tumours, so it makes the simulation work be more significant.We have made some attempts on PDT with computer simulation technology. These attempts will have some theory significance to the research on digital virtual human and laser biology medicine and provide some referenced values to clinical practice in tumor treatments.