Cerebral Vascular Effects of Non-invasive Laserneedles Measured by Transorbital and Transtemporal Doppler Sonography

Abstract

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Laserneedles represent a new non-invasive optical stimulation method which is described for the first time in this paper. We investigated 27 healthy volunteers (mean age±SD: 25.15±4.12 years; range: 21–38 years; 14 female, 13 male) in a randomised cross-over trial to study differences between laserneedle acupuncture and manual needle acupuncture in specific cerebral parameters. Mean blood flow velocity (v _m) showed specific and significant increases in the ophthalmic artery during laserneedle stimulation (p=0.01) and during manual needle stimulation (p<0.001) at vision-related acupoints. At the same time insignificant alterations in v _m were found in the middle cerebral artery for both acupuncture methods. The eight laserneedles used in this study were arranged at the end of the optical fibres. Each fibre was connected to a semiconductor laser diode emitting at 685 nm with a primary output power of about 55 mW. Optical stimulation using properly adjusted laserneedles has the advantage that the stimulation can hardly be felt by the patient and the operator may also be unaware of whether the laserneedle system is active, and therefore true double blind studies in acupuncture research can be performed.