Effects of 1267 nm Illumination on Microcirculation Regulatory Mechanisms

This study explored the effects of 1267 nm laser irradiation on changes in blood flow parameters and activation of the regulatory mechanisms of the microcirculatory bed (MCB). Using laser Doppler flowmetry (LDF) technique and time-frequency analysis of perfusion signals, changes in the MCB of 16 healthy volunteers, targeting the distal phalanx of the third finger with 1267 nm laser irradiation were evaluated. Results indicated no significant differences in perfusion between control and target measurements, likely due to blood flow redistribution caused by vessel dilation/constriction. However, differences in oscillation amplitudes in endothelial and myogenic ranges were observed, suggesting microcirculation self-regulation. Detailed analysis revealed characteristic peaks in the endothelial range during and after irradiation, indicating endothelial mediator release. It is assumed that the identified effects may be related to the singlet oxygen generated by 1267 nm laser irradiation, which directly affects the MCB, manifesting as endothelium-dependent vascular activity.