Influence Of Oxygen Pdt Effects

Photodynamic therapy is a new therapeutics to diagnose and cure aliment by photodynamic action. During the curing process, photosensitizer,light,oxygen,these three factors should combine together to produce the active oxygen needed for the curing. There are many parameters in the process, and uncertainty factors of the three factors is outstanding, so it is important to study the connections between the three factors and every parameters. While, it is the II mechanism that plays the main role in the therapy, that is the producing of cytotoxin singlet oxygen affected by the oxygen. The thesis mainly study the effect on PDT of oxygen, and contains the following parts:Firstly, the basic principle of PDT is illustrated, some main factors during the process are analyzed, and the characteristics of PDT are introduced simpleness.Secondly, the oxygen distribution in normal structure and neoplastic tissue are shown; Tumor oxygenation in different situations are discussed, together with the factors which limit the oxygen content in cancer structure.Thirdly, by the mathematical simulation of phootobleaching, the effect the three factors have in velocity of photobleaching is analyzed: under different fluence rate, photosensitizer concentration,oxygen concentration the relations between photobleaching velocity and depth of structure.Flnally.based on the light energy distribution in structure, and on the foudation of the relation equations of every factor and singlet oxygen producing velocity, we do research on the effect the optical power density, oxygen concentration have on the singlet oxygen velocity, and get the singlet oxygen distribution chart in different optical power density and oxygen concentration.