University of Electronic Science and Technology of China, Chengdu, China.
Biomedical Engineering Institute, Chinese Academy of Medical Science and Peking Union Medical College, Tianjin, China.
J Biophotonics. 2019 Feb;12(2):e201800173. doi: 10.1002/jbio.201800173. Epub 2018 Oct 1.
One of the challenges in transcranial low-level laser therapy (LLLT) is to optimally choose illumination parameters, such as wavelength. However, there is sparse study on the wavelengths comparison especially on human transcranial LLLT. Here, we employed Monte Carlo modeling and visible human phantom to compute the penetrated photon fluence distribution within cerebral cortex. By comparing the fluence distribution, penetration depth and the intensity of laser-tissue-interaction within brain among all candidate wavelengths, we found that 660, 810 nm performed much better than 980, 1064 nm with much stronger, deeper and wider photon penetration into cerebral tissue; 660 nm was shown to be the best and slightly better than 810 nm. Our computational finding was in a surprising accordance with previous LLLT-neurobehavioral studies on mice. This study not only offered quantitative comparison among wavelengths in the effect of LLLT light penetration effectiveness but also anticipated a delightful possibility of online, precise and visible optimization of LLLT illumination parameters.
经颅低水平激光疗法（LLLT）面临的挑战之一是优化选择光照参数，如波长。然而，关于人类经颅 LLLT 的波长比较研究甚少。在这里，我们采用蒙特卡罗建模和可视人体模型来计算大脑皮层内穿透光子的辐照量分布。通过比较所有候选波长的辐照量分布、穿透深度和激光-组织相互作用的强度，我们发现 660nm、810nm 比 980nm、1064nm 表现更好，具有更强、更深和更宽的光子穿透脑组织的能力；660nm 是最佳选择，略优于 810nm。我们的计算结果与之前关于小鼠的 LLLT-神经行为研究非常吻合。这项研究不仅提供了 LLLT 光穿透效果中波长的定量比较，而且还预测了在线、精确和可视的 LLLT 光照参数优化的可喜可能性。
