The fluctuating nature of microvascular blood flow in the forehead skin determines the level of the biological signal recorded by optical methods for analyzing the body’s vital signs.

OBJECTIVE

To study the functional state at rest and the constrictor activity of the microcirculation of the forehead skin using laser Doppler flowmetry in males, depending on the position of the body (lying on the back and sitting).

MATERIALS AND METHODS

The study included 15 males (mean age 44.6±10.1 years). Physical examination, history assessment, anthropometry with body mass index calculation, and laser Doppler flowmetry with wavelet analysis of the forehead skin on both sides were performed using portable laser analyzers. These procedures were conducted at rest and during a constrictor breathing test in both supine and sitting positions.

RESULTS

The results indicate an increase in the amplitude and perfusion efficiency of the endothelial, myogenic, neurogenic, and venular mechanisms of microcirculatory blood flow modulation, as well as variability in the sitting position (p<0.05), in the skin of the forehead on both sides. In the skin of the left side of the forehead, an increase in tissue perfusion and a decrease in the perfusion efficiency of pulse vibrations were found.

CONCLUSIONS

The data obtained suggest the effect of body position on the level and characteristics of the biological signal recorded by laser and optical research methods, which is especially relevant when the left side of the forehead is a region of interest. Further research is required to study the changes in indicators recorded from the skin surface using optical methods at different body positions. Additionally, a direct analysis of the relationship between the oscillatory nature of blood flow, the level of the recorded signal, and the obtained indicators of the state of the body is needed.