A Numerical Analysis of Laser Surgery of Port Wine Stain Based on Computer Simulation

Cryogen spray cooling (CSC) was proved to be an effective method to avoid the hyper-thermal injury in epidermal layer during the treatment of Port Wine Stain. A numerical analysis was performed to show the thermal history during the cryogen spray process. The analysis reveals that CSC not only reduces the surface temperature and protects the skin surface from burning but also makes a high energy dose possible to improve the clinic effect. The impact of the heat transfer coefficient on the cooling effect of CSC was also examined. One finds that the surface temperature decreases as the heat transfer coefficient increases and a high initial temperature improves the clinical result by increasing the final temperature in the PWS layer.