Temperature distributions in laser-heated biological tissue with application to birthmark removal

The time-dependent temperature distributions produced within thermally homogeneous media heated by a moving laser beam with Gaussian and uniform power density profiles are examined using a time-domain method based on Green's functions. Regions of finite length, width, and depth within the medium having exponential power absorption are considered. The temperature distribution is written as a single integral with respect to time of simple functions and the resulting expressions have been used to model the heating of blood vessels for birthmark (port-wine stain) removal. The temperature distributions obtained are in good agreement with those produced using Monte Carlo optical and finite difference thermal models.