Detailed calculations of the thermal

Detailed calculations of the thermal response and ablation of biological tissue exposed to 10// laser radiation are presented. For most of the calculations shown, tissue response was modeled using generalized computer codes that were originally developed to model the laser-induced response of a variety of non-biological materials. The models are applicable at any wavelength for which the absorption cross section in the tissue is large compared to the scattering cross section. In this initial study, soft tissue has been modeled as a single component material with thermal and optical properties very similar to that of water. The predominant phenomena treated are in-depth laser absorption, thermal conduction, and surface vaporization. In-depth thermal damage of tissue is calculated by incorporating into the codes a reaction for the thermal denaturation of tissue protein. Model calculations are presented for exposures ranging from low power CW exposures of a few watts per cm2 and exposure times of tens of seconds to single-pulse exposures with peak irradiances of several megawatts per cm2 and microsecond exposure durations. Where pos­ sible, model predictions are compared to available experimental data and the implications of the comparisons are discussed. Recommendations for future modeling improvements are also presented.