Electrical Impedance of Acupuncture Meridians: The Relevance of Subcutaneous Collagenous Bands

Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America.
PLoS ONE (Impact Factor: 3.23). 07/2010; 5(7):e11907. DOI: 10.1371/journal.pone.0011907
Source: PubMed


The scientific basis for acupuncture meridians is unknown. Past studies have suggested that acupuncture meridians are physiologically characterized by low electrical impedance and anatomically associated with connective tissue planes. We are interested in seeing whether acupuncture meridians are associated with lower electrical impedance and whether ultrasound-derived measures--specifically echogenic collagenous bands--can account for these impedance differences.
In 28 healthy subjects, we assessed electrical impedance of skin and underlying subcutaneous connective tissue using a four needle-electrode approach. The impedances were obtained at 10 kHz and 100 kHz frequencies and at three body sites - upper arm (Large Intestine meridian), thigh (Liver), and lower leg (Bladder). Meridian locations were determined by acupuncturists. Ultrasound images were obtained to characterize the anatomical features at each measured site. We found significantly reduced electrical impedance at the Large Intestine meridian compared to adjacent control for both frequencies. No significant decrease in impedance was found at the Liver or Bladder meridian. Greater subcutaneous echogenic densities were significantly associated with reduced impedances in both within-site (meridian vs. adjacent control) and between-site (arm vs. thigh vs. lower leg) analyses. This relationship remained significant in multivariable analyses which also accounted for gender, needle penetration depth, subcutaneous layer thickness, and other ultrasound-derived measures.
Collagenous bands, represented by increased ultrasound echogenicity, are significantly associated with lower electrical impedance and may account for reduced impedances previously reported at acupuncture meridians. This finding may provide important insights into the nature of acupuncture meridians and the relevance of collagen in bioelectrical measurements.

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Available from: Andrew C Ahn, Jul 23, 2014
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    • "Both scientific definition and anatomical substrate of acupoint remains debatable [7-16]. The correspondence to a dermatome pattern [7], the presence of neurovascular bundles [8,9], different types of terminal nerves [9-11], and a reduced skin electric impedance [12,13] are amongst the most common characteristics attributed to acupoints [14,15]. The material basis of acupuncture is the nerves since the nervous system is the common factor between many scientific evidence on acupuncture’s efficacy [16]. "
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    ABSTRACT: Analysis of the relationship between the nervous system anatomy and the therapeutic characteristics of all acupuncture points in the channel network may provide new insights on the physiological mechanisms underlying acupuncture stimulation for prevention, treatment, and rehabilitation purposes. This study investigates the association between the similarity of acupoints' dermatomes, traditional actions, and contemporary indications. Channel acupoints had their characteristics annotated from a literature review of four topographic atlases of Chinese medicine and one atlas of human anatomy: initials of the channel's name (n = 14), sequential number in the channel (n = 67), acupoint's name (n = 361), dermatomes related to perpendicular needle insertion (n = 31), traditional actions (n = 848), and contemporary indications (n = 1143). Jaccard's similarity coefficient quantified the similarities between dual acupoints. All dual acupoints were evaluated to generate similarity matrices for each nominal variable. Cross-tables were generated by simultaneous classification of variables into levels of similarity with respect to: dermatomes versus traditional actions, dermatomes versus contemporary indications, and traditional actions versus contemporary indications. Goodman-Kruskal gamma and Rousson gamma*2 were calculated based on cross-tables, bootstrap and permutated samples to evaluate the association and determination coefficient between variables, respectively. Significant associations were observed between levels of similarities of dermatomes and traditional actions (gamma = 0.542; P < 0.001), dermatomes and contemporary indications (gamma = 0.657; P < 0.001), and traditional actions and contemporary indications (gamma = 0.716; P < 0.001). Similarities of dermatomes explained 16% of the variance of traditional actions and 25% of contemporary indications. Traditional actions explained 30% of the variance of contemporary indications. The association between traditional actions and contemporary indications was the highest one (gamma = 0.716, 95% confidence interval (95% CI) = [0.715; 0.719]), followed by the association between dermatomes and contemporary indications (gamma = 0.622, 95% CI = [0.621; 0.623]), and between dermatomes and traditional actions (gamma = 0.446, 95% CI = [0.444; 0.447]), all with P < 0.001. The similarity of dermatomes between dual acupoints partially determined the similarity of traditional actions and contemporary indications, therefore dermatomes partially determine the therapeutic efficacy of acupuncture.
    Chinese Medicine 12/2013; 8(1):24. DOI:10.1186/1749-8546-8-24 · 1.49 Impact Factor
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    • "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. "
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    ABSTRACT: Many studies have explored the relationship between skin microcirculation and meridian activation. However, few studies have examined blood perfusion coherence along the meridians, and other studies have suggested that the skin vasodilator response relates to age. This study investigated blood perfusion coherence characteristics along the meridian of the forearm in healthy volunteers. A total of 15 young subjects (25.53 +/- 2.20) and 15 middle-aged subjects (50.07 +/- 3.37) were recruited for this study. Before experiments, each subject was placed in a temperature-controlled room for 60 min. Skin blood perfusion from five points was recorded simultaneously using a full-field laser perfusion imager before and after inflatable occlusion. The five points comprised three points located on the pericardium meridian, and two points from different locations. Coherence analysis between these points was performed at different frequency intervals from 0.0095 to 2 Hz. In young subjects, the coherence value was unchanged before and after occlusion, and there was no significant difference in coherence value between meridian-meridian points (M-M) and meridian-parameridian points (M-P). In middle-aged subjects, the coherence value increased significantly in both M-M and M-P at frequency intervals of 0.14-0.4 Hz, 0.4-1.6 Hz, and 1.6-2 Hz. However, there was no significant difference in coherence values between M-M and M-P. Inflatable occlusion can increase middle-aged subjects' blood perfusion coherence value of the forearm. However, there is no specificity in meridian location.
    BMC Complementary and Alternative Medicine 11/2013; 13(1):327. DOI:10.1186/1472-6882-13-327 · 2.02 Impact Factor
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    • "Based on the results of the current study and our review of the literature, we suggest that the hydrodynamic of waveforms fluid flow and interstitial fluid concepts [70] of the meridians and acupuncture points explains the reported transmission of current [30, 32], acoustic responses [33, 71], thermal responses [34, 35], optical transmissions [34, 43], isotope passages [36, 37, 72], hydrodynamic analysis [40, 73], and PLB stimulation [13, 14] in meridians. The hypothesis that meridians are open channels of interstitial fluid seems to be accepted, based on evidence-based research. "
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    ABSTRACT: The mechanisms of acupuncture remain poorly understood, but it is generally assumed that measuring the electrical conductivity at various meridians provides data representing various meridian energies. In the past, noninvasive methods have been used to stimulate the acupuncture points at meridians, such as heat, electricity, magnets, and lasers. Photoluminescent bioceramic (PLB) material has been proven to weaken hydrogen bonds and alter the characteristics of liquid water. In this study, we applied the noninvasive PLB technique to acupuncture point irradiation, attempting to detect its effects by using electrical conductivity measurements. We reviewed relevant literature, searching for information on meridians including their wave-induced flow characteristics.
    Evidence-based Complementary and Alternative Medicine 11/2013; 2013:739293. DOI:10.1155/2013/739293 · 1.88 Impact Factor
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