Chapter 10 - Modeling and Experimental Analysis of Thermal Therapy during Short Pulse Laser Irradiation

Abstract

Pulsed lasers are widely used for therapeutic medical applications. It is helpful to perform numerical modeling and analysis prior to treatment in order to better predict the optimal thermal dose delivered to tissues and reduce unwanted damage to surrounding healthy tissue through heat diffusion. In response to the many challenges inherent to performing laboratory experiments to characterize laser–tissue interactions, a novel temperature controlled synthetic tissue phantom with countercurrent synthetic blood flow was designed and developed. The phantoms were irradiated with a short pulse Nd:YAG laser for cases both with and without blood flow. A finite element model was developed to analyze the effects of blood flow on temperature rise in the tissue phantoms and was validated by the experimental measurements. Both the numerical modeling results and the experimental measurements indicated that subsurface countercurrent blood flow decreased peak surface temperature rises that result from short pulse laser irradiation. The novel temperature controlled vascularized synthetic tissue phantom design could be adapted for use in the experimental optimization of various thermal treatments. These phantoms present a viable alternative to live animals for use in analyzing the thermal effects of a given laser therapy.