Effects of Electroacupuncture Stimulation at Frequencies Near the Heart Rate on the Microcirculatory Blood Flow

Motivation: The frequency of electroacupuncture (EA) could substantially influence the induced response. We compared the effects of EA at frequencies at around the heart rate (HR) and 50%-higher-than-HR frequency on the microcirculatory blood flow (MBF). Methods: Skin-surface laser Doppler measurements were performed in healthy volunteers in three groups: (1) Group A (n=14), premeasurement-HR-frequency EA was applied; and (2) Group B (n=13), 50%-higher-than-HR-frequency EA. (3) Group C (n=16), no EA was applied. Each experiment involved recording a 20-min baseline-data sequence followed by an effect-data sequence obtained at 0–20 min after stopping 20 min of 0.08-mA EA. Results: Beat-to-beat time-domain waveform analysis (including the pulse width, flow rise time, and microcirculatory blood-flow variability) revealed that following EA, the MBF supply at the stimulated site was improved in both groups, and that the MBF perfusion through arteriolar openings appeared to be more efficient in Group A than in Group B. Conclusion: The obtained data may help to establish a new noninvasive method for studying the mechanisms underlying the MBF response induced by EA.