Effect of polarized light irradiation around the stellate ganglion area on temperature and blood flow at hand and head

Controlled double blind trial in healthy adult volunteers

Abstract

Objective: The purpose of this study was to investigate the effects of polarized light irradiation around the stellate ganglion (SG) area on temperature and blood flow in the hand and head.
Methods: Twenty healthy adult volunteers (10 males, 10 females) were enrolled in a double- blind, crossover and placebo-controlled study after institutional approval and informed consent were obtained. Each volunteer received irradiation for 7 minutes at 80% and 0% (placebo) power on separate days in a randomized fashion. Room temperature, deep temperature of the hands, surface temperature of their middle fingers, blood flow in the thumbs, temperature of tympanums, blood flow in the middle brain artery, and oxygen saturation of the forehead were measured continuously from 15 minutes before to 30 minutes after irradiation. The values of parameters were collected for statistical analysis before, immediately after (7 minutes) and 30 minutes after the irradiation.
Results: No significant changes of measured parameter were observed by the irradiation.
Conclusion: Polarized light irradiation around the SG area had no effect on temperature or blood flow in the hand or head in healthy adults.