Potential Thermal Effect of Stimulating Brain Tissue during Low Level Laser Therapy

Abstract

Low level laser therapy (LLLT) is a promising and noninvasive technique in treating a multitude of medical conditions by activating healing and cell regeneration. It is also used to stimulate the brain function. The aim of this study is to investigate the Potential Thermal Effect of LLLT during stimulation. LLLT is characterized by low-intensity treatment. However, what is the dose of intensity required to stimulate the brain without a possible thermal effect. To address this, a simulation model was proposed and implemented using Finite Element Analysis within the COMSOL Multiphysics software package. This approach aims to determine the optimal combination of energy density and irradiation time that would yield the most effective enhancement of cell activity in the brain. The best power density is 166 mW/cm 2 (joule density 20 J/cm 2 ) and 2 min exposure is enough to stimulate the brain when applying 808 nm with optic cap that gives a laser spot size of 3 cm 2 . The determination of optimal parameters is imperative in the context of brain activation. It is crucial to ensure that the tissue temperature does not exceed 0.5 °C, which is the permissible temperature limit for effective stimulation. The findings will provide valuable insights into the optimization of LLLT protocols, thereby establishing a foundation for its safe and effective application in therapeutic settings.