Evaluation of Transcranial NIR Light Propagation for Photo-biomodulation of Neurons Using Mesh-Based Monte Carlo Modeling

Abstract

Research has shown that photo-biomodulation of neurons with near-infrared (NIR) light can stimulate their regeneration, and thus various research groups have developed devices that emit NIR light transcranially (through the skull) to stimulate neural growth in the brain in an effort to treat neurological diseases such as Multiple Sclerosis (MS) and Alzheimer’s. However, it is not clear that clinical device designs illuminate cells in the brain with similar parameters as those shown effective for neuro-regeneration in pre-clinical work. This project employed computational modeling and simulations to assess the effect of device design parameters on transcranial light propagation, in order to optimize illumination of brain tissue and cells and thus ultimately improve clinical results of transcranial NIR-emitting devices for neuro-regeneration. Specifically, this project consisted of the development of two computational models for transcranial NIR-emitting devices and the evaluation of three device parameters: wavelength, photon number, and power density, on transcranial NIR light propagation.