Characterisation of Human Skin Impedance at Acupuncture Point Pc4 Ximen and pericardium meridian using the four-electrode method

Abstract

Introduction Traditional Chinese medicine offers several theories to explain the mechanism of acupuncture. One of these theories proposes that acupuncture points and meridians have unique electrical properties and their electrical skin impedance is lower than surrounding areas. The aim of this study was to evaluate the differences in electrical skin impedance between PC4 and the pericardium meridian compared with the surrounding areas. Methods Eighteen healthy subjects (10 women) were recruited to participate in the study. An impedance meter based on the four-electrode technique was designed specifi cally for the study. Twenty-fi ve points were marked on the skin: one on the point PC4, four others on the pericardium meridian and 20 points around it. The electrical impedance of each point was measured with the four-electrode device. Results The mean electrical skin impedance at PC4 was signifi cantly different from the 20 of the surrounding points but not signifi cantly different from the four adjacent points. The mean skin impedance of the fi ve points over the pericardium meridian was signifi cantly different from that of parallel rows of points using repeated measures analysis of variance (p<0.001) Conclusion Within the possible limits of this measurement technique, skin impedance along the pericardium meridian is lower than surrounding areas, supporting the idea of different properties of the pericardium meridian compared with the control areas. Evidence on skin impedance at PC4 is inconclusive and further studies are needed. INTRODUCTIONAn important concept in traditional Chinese medicine is Qi which is believed to fl ow through channels called meridians. Acupuncture points are located along these meridians. Stimulating these points is believed to affect the quality and quantity of Qi fl ow and thus affect body systems. Although acupuncture points and meridians are basic issues of Chinese medicine, there is not yet a complete explanation for this system.Characterisation of human skin impedance at acupuncture point PC4 Ximen and pericardium meridian using the four-electrode method Traditional Chinese medicine offers several theories to explain the mechanism of acupuncture. One of these theories proposes that acupuncture points and meridians have unique electrical properties and their electrical skin impedance is lower than surrounding areas.1-4 Many devices have been developed to locate the right acupuncture points and to diagnose the diseases based upon this theory.This phenomenon was reported independently by different scientists in the 1950s. 5-7Although many investigators have tried to fi nd the relationship between acupuncture and electrical properties of the skin, a review article by Ahn et al in 2008 showed that, among 320 articles referring to electrical resistant and acupuncture points, only 18 met the criteria for further evaluation. These authors concluded that there is not enough evidence to prove conclusively that acupuncture points or meridians are electrically distinguishable and more r...

Is An Acupuncture Point Identifiable with Skin Electrical Resistance Measurement?

“…[1][2][3][4][5][6] The AP is reported to be located intramuscularly; if it is within the dermal and subcutaneous tissues, cutaneous wounds and liposuction could extensively destroy the AP. By placing the bipolar electrodes on top of the skin over a purported AP, the current would flow superficially between the electrodes and would probably bypass the area of interest ( figure 1B).…”

“…Some researchers have found that the electrical resistance of the skin over an AP is lower than that over a non-AP, and proposed the finding as indirect evidence of the existence of APs. [1][2][3][4][5][6] However, the precision of skin electrical resistance measurement can be influenced by numerous factors such as dryness of skin, skin thickness, size of the sensing electrode, pressure applied on the electrode, interelectrode distance, room temperature and humidity. 7 Most of the previous studies on AP identification were done with the sensing electrode being stabilised by hand [1][2][3][4][5] ; however, it is likely that small motions of the hand-held electrode could alter the reading of skin resistance and even bias the measurement.…”

Acupoint Activation: Response in Microcirculation and the Role of Mast Cells

“…Thus, more and more attention has been focused on the relationship of acupuncture and circulation [ 11 , 12 , 13 ]. In the meridian study area, the broad consensus in meridian study is a lower impedance along the meridians [ 14 , 15 ]. Usually, the impedance of the skin is proportional to the interstitial fluid volume which comes from microcirculation, so microcirculation might be an index for meridian activation [ 16 ].…”

Pilot study of blood perfusion coherence along the meridian in forearm

“…However, it is difficult to evaluate the activation of meridians. Until now, the broad consensus in meridian studies has been the lower impedance along the meridians [2,3]. Usually, the impedance of the skin is proportional to the interstitial fluid volume arising from microcirculation; thus, microcirculation may be an index for meridian activation.…”