Changes in transmission spectrum of human venous blood under action of low-intensity He-Ne laser

We report experimental evidence of light-induced changes in the transmission spectrum of human venous blood under the action of low-intensity radiation from He-Ne laser. The transmission spectra of diluted and nondiluted heparinized human blood have been analyzed before, after and in the course of irradiation. When irradiating diluted blood, no changes in the blood spectrum have been detected. However, irradiating nondiluted blood, the reproducible variations of the blood transmission spectrum in the range of 640-805 nm have been observed. These changes correlate with oxygen saturation. The decreased oxygen saturation in venous blood is stabilized at the level of about 70-80% from the initial one after 5-8 procedures of laser irradiation. The decrease of oxygen saturation in venous blood after the course of treatment means that irradiation of He-Ne laser permits an addition quantity of oxygen to be involved in exchange processes. The changes of oxygen saturation in venous blood after 1-3 procedures of irradiation can be used as a method to detect an individual sensitivity to intravein laser irradiation.