FIG. 5.

Diagram of structures present on coronal view at vertex of the skull, where one of the LED cluster heads was placed. When placed here, an acupuncture point located on the Governing Vessel (GV) meridian was treated (GV 20). See text for historical use of this point.⁵¹ Several other structures were also likely irradiated with the red/NIR LED cluster heads, including the valveless emissary veins that interconnect with veins in the superior sagittal sinus. Only 3% of NIR photons delivered at the surface of the skull are estimated to reach 1 cm deep (to cortex).³⁶ Suture lines, and the superior sagittal sinus, may be areas where red/NIR photons have better potential for penetration.