Changes in skin impedance and heart rate variability with application of Acu-TENS to BL 13 (Feishu)

Objectives: To investigate the change of skin impedance of acupoints along the Lung meridian in response to transcutaneous electrical nervous stimulation over an acupoint (Acu-TENS) over BL13 (Feishu). Design: This was a double-blinded, randomized, controlled crossover study. Settings/location: The study was conducted in a laboratory. Subjects: Eighteen (18) healthy individuals comprised the study subjects. Interventions: The intervention was a session of 45-minute Acu-TENS (application of TENS on BL13, Feishu) or placebo-TENS (similar to Acu-TENS but without electrical output). Outcome measures: Skin impedance at 10 acupoints on the Lung meridian was recorded before and after the 45-minute intervention period. Heart rate variability during the intervention was analyzed from continuous heart rate monitoring. Results: Skin impedance at all acupoints along the lung meridian decreased significantly after Acu-TENS, when compared to placebo-TENS (p<0.05). A significant reduction in sympathetic activity was also observed after Acu-TENS (p=0.012). Conclusions: Acu-TENS appears to modify skin impedance of acupoints along a related meridian and possibly modulates sympathovagal balance.