Selective Photothermolysis Of Intense Pulsed Light (IPL) In Biotissue And Experiment Study

Selective photothermolysis is the theoretic foundation of photorejuvenation. The key factor affecting selective results in intense pulsed light (IPL) treatment is the irradiation parameters. In this dissertation, combining numerical analysis and thermal damage experiment in rat skin, we present the elementary results of the study of selective effects induced by several parameters, including wavelength, energy density, pulse duration and number of pulses.At first, a short introduction to the history and actuality of the study of photorejuvenation were briefly reviewed and the problems in present were pointed out. Then the purpose of our study and the main study contents were also presented.Secondly, selective photothemolysis, the mechanism of photorejuvenation was introduced. Then combining IPL characteristic, the influence of different wavelength, pulse duration and energy density on photo-thermal effects was discussed.Thirdly, the numerical analysis of photo-thermal response between IPL and skin tissue was given. Using Monte Carlo simulation method, distribution of light fluence and energy deposition which used as thermal source were obtained. Then the temperature profile in skin under contact cooling condition was given using 1-D finite difference method. Simulation results with different parameters were analysed.Finally, thermal damage experiment in vivo rat skin irradiated by IPL with different parameter was studied. The thermal damage depth deduced by different wavelength, energy density and number of pulses were presented and compared.