[Comparative study of reflectance spectroscopy of human laogong acupoint and non-acupoint tissues irradiated by near-infrared laser].

Characteristics and differences of reflectance spectroscopy of human Laogong acupoint and non-acupoint tissues before and after irradiation by different power of laser were studied in the spectral range from 400 to 1 000 nm. A wavelength 808 nm semiconductor laser was used for irradiation at the power of 20, 50 and 100 mW for ten minutes. Reflectance spectra of human Laogong acupoint and non-acupoint tissues were measured by using an AvaSpec-2048 optical fiber spectroscopy with an integrating sphere attachment. The result shows that before irradiation the shape of the reflectance spectra of Laogong acupoint and non-acupoint is similar, they have the same troughs at 423, 544, 577 and 980 nm, and the reflectance for Laogong acupoint and non-acupoint at these wavelengths is 17.1%, 26.1%, 25.9% and 35.0%, and 17.1%, 27.6%, 28.1% and 36.5% respectively. But from 475 to 1 000 nm, the reflectance of Laogong acupoint is smaller than that of non-acupoint. After being irradiated by semiconductor laser at the power of 20, 50 and 100 mW, there is a very significant decrease in the reflectance of Laogong acupoint compared to that before irradiation, and the higher the power, the lower the reflectance. But there is just a small decrease in the reflectance for non-acupoint compared to that before irradiation. From the above results, it is clearly seen that Laogong acupoint is different from non-acupoint on reflectance spectroscopy, and Laogong acupoint is more sensitive to laser irradiation than non-acupoint tissue.