Effects of electrical acupuncture on acupoint BL15 evaluated in terms of heart rate variability, pulse rate variability and skin conductance response.

In this research, heart rate variability (HRV), pulse rate variability (PRV) and human skin conductance (SC) of all acupoints on Heart Meridian were used to evaluate the effects of electrical acupuncture (EA) on acupoint BL15 (Bladder Meridian). Ten healthy volunteers (aged 23 +/- 6) were selected as the control group on the first day, and then used again as the experimental group on the second day. The control group received sham EA during the study, while subjects of the experimental group were stimulated by 2 Hz EA on acupoint BL15 for 10 minutes. Electrocardiogram (ECG), wrist blood pressure pulse meter and skin conductance response (SCR) device were used to measure and analyze HRV, PRV and SCR for the two groups before and after stimulation. From the spectrum analysis of ECG and pulse pressure graph, we found that the EA applied on BL15 could induce a significant increase in the normalized high frequency power (nHFP) component of HRV and PRV, as well as a significant decrease in the normalized low frequency power (nLFP) part (p < 0.05). Moreover, both the heart rate and pulse rate were reduced in the analysis of the time domain of ECG and PRV. Furthermore, most of the SCR values at acupoints were decreased after stimulation. These results also indicate that the stimulation of BL15 by EA could cause relaxation, calmness and reduce feeling of tension or distress.