Violet laser acupuncture--part 1: Effects on brain circulation.

Violet laser acupuncture using a wavelength of 405 nm has been investigated in only a few scientific studies. The aim of this study was to provide selective evidence of a specific effect of violet laser acupuncture on mean cerebral blood flow velocity using a Doppler ultrasound technique. A transcranial Doppler sonography construction was developed especially for this study to monitor blood flow profiles in the basilar and middle cerebral arteries simultaneously and continuously. The acupuncture point Dazhui on the upper back was tested in a controlled study with 10 healthy volunteers (24.9 ± 3.3 years, mean age ± SD; 5 females, 5 males). In addition to an on/off-effect, violet laser stimulation increased the blood flow velocity in the basilar artery significantly (p < 0.001) compared with the reference interval before laser acupuncture. In the middle cerebral artery, only minimal, nonsignificant changes in blood flow velocity were seen. Metal needle acupuncture at the same point intensified the effects; however, blood flow profiles did not change significantly during and after stimulation with a deactivated violet laser.