Fig. 1.

Number of published articles using different tPBM wavelengths and light sources for brain disease treatment in pre-clinical studies and clinical trials from 2002 to 2023. (a) The number of published articles using different tPBM wavelengths in pre-clinical studies. (b) The number of published articles using different tPBM wavelengths in clinical trials. (c) The number of published articles using different tPBM sources in pre-clinical studies. (d) The number of published articles using different tPBM sources in clinical trials. Notes: the data are summarized from Refs. ^20–23 and ^51–70, (ischemic stroke), ^71–73 (HI), ⁷⁴ (intracerebral hemorrhage), ^{25–28, 75–83} (AD), ^{29–34, 84–96} (PD), ^97–99 (multiple sclerosis), ^{35–40, 100–116} (TBI), ¹¹⁷ (possible chronic traumatic encephalopathy), ^{41–44, 118–126} (depression), ^{45–50, 127–136} (aging), and ^137–141 (epilepsy).