<title>Modeling and numerical simulation of the infrared photoablation process</title>

Abstract

Photoablative tissue processing at the wavelength (lambda) approximately equals 3 micrometer is of great interest in many medical applications but not yet really understood. A mathematical model of the photoablation process using a free- running infrared laser has been developed. It includes evaporation and thermoelastic pressure generation and was solved using the finite-element-method. Simulated thermoelastic pressure transients are in good agreement with the experiment. It has been shown, that the temperature dependence of the absorption and the volumetric expansion cannot be neglected. With higher laser intensities strong recoil pressure transients (greater than or equal to 100 bar) and strong thermoelastic pressure transients due to a partially evaporation are given. For this reason a new model including large tissue expansions, tissue overheating and recoil induced pressure transients has been developed and presented.