| Laser has high monochromaticity, high directivity, high brightness and goodcoherence characteristics. Once Laser comes out, it has been widely applied in clinicaltreatment. Most of the applications are related to thermal effects, such as high feverlaser therapy, condensation and laser surgery. In order to ensure treatment safety andimprove efficiency, it is important to put the photo thermal effect of the biologicaltissue and thermal damage into research. An accurate analysis of heat transfer andthermal damage is particularly crucial.Firstly, this project based on the dual-phase lag model, according to the actualsituation of the laser in the thermal conductivity of biological tissues by usingnumerical simulation method, showed a simulation of under laser irradiation ofbiological tissues non-Fourier heat transfer phenomenon.Secondly, this project illustrated an experimentally study to the regular pattern ofcontinuous He-Ne laser irradiation of rat skin tissue temperature changing. Theexperiment used a thermocouple inserted from the opposite side of the laser irradiationsurface. By changing the parameters of the laser irradiation time and power, the data ofthe location of tissue temperature change every signal acquisition in accordance withthe sampling rate had been put into record.This paper built a numerical simulation of the finite difference method (FDM),and simulated the numerical of the dual phase lag model. Change the values ofτTandτ_q,the dual phase lag model,the Fourier model and the hyperbolic thermal wavemodel,numerical simulation results are compared and analyzed.The simulation resultsshow that:whenτ_Tandτ_qare equal and small,numerical simulation results of thedual phase lag model and the Fourier model are equal.Otherwise even ifτ_T=τq,thedual phase lag model to decribe the thermal conductivity is also different from thetraditional Fourier model.The pre-laser irradiation of biological tissue,theτ_qimpact on the temperature was even greater.When laser stopped,theτ_Timpact on the temperaturewas even greater.Whenτ_qfixed in the16s,τ_Tchanges,after the abolition of the laserirradiation of biological tissue temperature changes as the value ofτ_Tincreases withincreasing.When the value ofτ_Tfixed in the0.05s,τ_qchanges,the value ofτqbecame bigger,the tissue temperature was higher.The experimental study of the law of a continuous He-Ne laser irradiation of ratskin tissue temperature change over time, using He-Ne laser, infrared radiationthermometer and a thermocouple probe experimental tool, by changing the laserirradiation time and power, the surface of rat tissues and subcutaneous tissue1mmtemperature changes over time. The experimental results show that, when the laserexposure, the surface of rat tissues and subcutaneous tissue1mm area at thetemperature during the irradiation with increasing irradiation time increased rapidlywhen the laser irradiation is stopped, the surface temperature of the rat tissues rapiddecline, while The rat subcutaneous tissue1mm at the temperature of slow decline.When the surface of rat tissues used the same laser energy irradiation with increasingpower, the temperature of the tissue surface correspondingly increased in tissuesurface temperature fluctuations phenomenon. In the25s after the surface temperaturehas stabilized. The tissue surface temperature decreases with the increase of the radialdistance of the laser center. |
