An analysis of the kinetics of thermal damage and movement of damage front in laser irradiated egg white

Abstract

Some of the major applications of laser surgery involve the photocoagulation of diseased tissue, with minimal or no damage to the surrounding healthy tissue. There is a growing need for a model for the quantification of thermal damage. The models presently available in the literature assume biological tissue to be composed of a single component having a single rate of damage. But recent studies have shown that a distribution of rate parameters rather than a single rate parameter, best describes the process of thermal coagulation. This study assumes tissue to be composed of two or more components, having different rates of damage. The results of this model are then used to find an effective rate of damage for a single rate model which would yield the same end concentrations as the multi rate model. Results indicate that the difference between the single rate and the multi rate predictions is highly predominant for relatively lower power settings, for the biokinetic coefficient values used in this research. As the power is increased, a single rate model effectively describes a multi rate model, in the prediction of damage and movement of damage front. The movement of damage front was also studied experimentally using Digital Image Processing techniques. The damage model predicted by this study qualitatively follows the theoretical models available in the literature.