Takuma Kogawa;Yousuke Nakamura;Soma Taniguchi;Hisashi Nakajima;Junnosuke Okajima;Atsuki Komiya;Shigenao Maruyama;Atsushi Sakurai
Recently, selective heating techniques by laser therapy have been proposed. Among them, laser therapy adopting metallic nanoparticles has garnered attention. By injecting metallic nanoparticles inside a tissue, high absorption can be achieved by the local surface plasmonic resonance at the surface of the nanoparticle. In particular, gold nanorods exhibit significantly high resonance against laser and their effectiveness has been investigated experimentally. However, the modeling of laser therapy by gold nanorods is limited, and a quantitative numerical simulation is required to further investigate the possibility of effective heating by gold nanorods. To investigate the effectiveness of selective heating by laser therapy with gold nanorods, a three-dimensional calculation of laser therapy is performed in this study. To model the thermal conduction and propagation of laser inside a tissue, the Pennes bio-heat transfer equation is applied. The radiative heat transfer is calculated using the radiation element method. The dispersion effect of gold nanorod injection is considered. Comparing the thermal damage between gold nanorod injection and noninjection cases, the performance of selective heating by gold nanorods is evaluated. Furthermore, the effect of gold nanorod injection location on the thermal damage is discussed. Numerical calculation results indicate that gold nanorod injection enables selective heating against the target as well as noninvasive heating on the tissue surface. Furthermore, the heating depth can be controlled by changing the injection location appropriately.