LASER-TISSUE INTERACTION MODELING WITH LATIS

The role of modeling in designing new treatment protocols and instrume nts is discussed. A computer program for modeling laser-tissue interac tion named LATIS is described. Interactions are divided into the proce sses of laser propagation, thermal effects, material effects, and hydr odynamics. Full coupling of the processes is taken into consideration. Applications in photothermal and photomechanical laser-tissue interac tions are briefly discussed. A detailed description is given of a part icular application of LATIS to study the effects of dynamic optical pr operties on dosimetry in photothermal therapy. Optical properties are functions of tissue damage, as determined by previous measurements. Re sults are presented for the time variation of the light distribution a nd damage within the tissue as the optical properties of the tissue ar e altered. It is found that proper accounting of dynamical optical pro perties is important for accurate dosimetry modeling. (C) 1997 Optical Society of America.