Characteristics of electrical skin resistance at acupuncture points in healthy humans

Connecting the dots: alterations in bioelectric activity at acupuncture Ting (Jing-Well) points following CV4 cranial manipulation

CONTEXT

The mechanisms by which osteopathic cranial manipulative medicine (OCMM) promotes health and healing have yet to be fully elucidated. One commonly utilized OCMM technique, compression of the fourth ventricle (CV4), has been theorized to balance autonomic nervous system (ANS) activity. There is growing evidence that the ANS also plays a significant mechanistic role in acupuncture. Potential connections between OCMM and acupuncture meridian theory largely remain unknown.

OBJECTIVES

By measuring specific electrical parameters at acupuncture points that have been shown to correlate with ANS activity, the objectives of this study were to: 1) determine if CV4 has any influence on the bioelectric properties of the acupuncture meridian system; and 2) determine if CV4 affects the ANS.

METHODS

A total of 77 males and females ages 18-78 years, all volunteers recruited by local flyers and personal or phone contact, were randomized into CV4 (n=40) and Sham (n=37) groups. All CV4 participants were treated by the same physician utilizing standard CV4 protocol. The Sham treatment, performed by a different physician, consisted of the supine participant's occiput resting passively on the physician's finger pads for a similar duration as those in the CV4 group. Among several devices developed to assess ANS activity at acupuncture points, evidence suggests that the Apparatus for Meridian Identification (AMI) is the most accurate and valid. Utilizing the AMI, bioelectric skin parameters were measured immediately before and after CV4 or Sham treatments. Student's or Welch's t tests and Wilcoxon tests were utilized for analysis of normally and non-normally distributed data, respectively.

RESULTS

Statistical significance was determined with a p value less than 0.05. Sham treatments showed insignificant (p=0.754) before vs. after differences in ANS activity measured at acupuncture points, whereas CV4 treatment significantly (p=0.00015) affected ANS activity.

CONCLUSIONS

This research suggests that CV4 has demonstrable biophysical effects on the acupuncture meridian system occurring via the ANS, and that the underlying mechanisms of OCMM and acupuncture may be related. Further studies are needed to clarify this.

Spatial and Temporal Electrodynamics in Acuzones: Test-Induced Kinematics and Synchronous Structuring. Phenomenological Study

Background: So far there is no confidence in the basics of acupoint/meridian phenomena, specifically in spatial and temporal electrical manifestations in the skin.Methods: Using the skin electrodynamic introscopy, the skin areas of 32 × 64 mm² were monitored for spectral electrical impedance landscape with spatial resolution of 1 mm, at 2 kHz and 1 MHz frequencies. The detailed baseline and 2D test-induced 2 kHz-impedance phase dynamics and the 4-parameter time plots of dozens of individual points in the St32-34 regions were examined in a healthy participant and a patient with mild gastritis. Non-thermal stimuli were used: (1) (for the sick subject), microwaves and ultraviolet radiation applied alternately from opposite directions of the meridian; and (2) (for the healthy one) microwaves to St17, and cathodic/anodic stimulation of the outermost St45, alternately.Results: In both cases, the following phenomena have been observed: emergence of in-phase and/or antiphase coherent structures, exceeding the acupoint conditional size of 1 cm; collective movement along the meridian; reversible with a reversed stimulus; counter-directional dynamics of both whole structures and adjacent points; local abnormalities in sensitivity and dynamics of the 1 MHz and 2 kHz parameters indicating existence of different waveguide paths.Conclusion: It is assumed that these findings necessitate reconsideration of some basic methodological issues regarding neurogenic/acupuncture points as spatial and temporal phenomena; this requires development of an appropriate approach for identifying the acuzones patterns. These findings may be used for developing new approaches to personalized/controlled therapy/treatment.

Low Electrical Resistance Properties of Acupoints: Roles of NOergic Signaling Molecules and Neuropeptides in Skin Electrical Conductance

Early studies from several independent laboratories demonstrated that acupoints possess the characteristics of low electrical resistance. New devices are developing to increase the reliability of electrical skin impedance measurements for counteracting the factors including skin dryness, skin thickness, size of the sensing electrode, pressure applied on the electrode, interelectrode distance, room temperature, and humidity. Morphological studies have identified that blood vessels, hair follicles, and nervous components are enhanced in the meridians/acupoints, which represent areas of potentially high neuronal activity. Recent evidence shows that nitric oxide (NO) concentrations are enhanced in skin acupoints/meridians. L-arginine-derived NO synthesis modifies skin norepinephrine (NE) synthesis/release in acupoints/meridians, and NO-NE activations play an important role in mediating the skin conductance responses to electrical stimulation. NOergic signaling molecules interact with gap junction and transient receptor potential vanilloid type-1. Other studies reported that the high conductance at acupoints is a result of the release of the neuropeptides substance P and calcitonin gene-related peptide during neurogenic inflammation in the referred pain area. Pathological body conditions caused considerable changes in skin conductance or impedance at acupoints. Although systematic research with an improved equipment and research design to avoid the influencing factors are requested for a definite answer in this field, the results from anatomical and biochemical studies consistently show that acupoints exist higher levels of nervous components, and NOergic signaling molecules and neuropeptides involved in the skin low resistance at acupoints. The increased interest in the acupoints/meridians has led to an open-minded attitude towards understanding this system, which is fundamental important to establish the valid aspects of scientific basis of Chinese medicine mechanisms and therapies.

The difference in heat transport characteristics of the heart and lung meridians: A comparative study of COPD patients and healthy subjects

BACKGROUND

The vast majority of previous studies focused on the relationship between 1 meridian and 1 organ, and the comparison and specificity between 2 meridians is rarely explored. Thus, the aim of this study is to compare the heat transport characteristics between 2 different meridians and the specificity between them will also be investigated.

METHODS

The Lung and Heart meridians are chosen for comparison of 2 different meridians. We will enroll 120 subjects and divide them into the healthy control group, chronic obstructive pulmonary disease (COPD) group and healthy intervention group, in a 1:1:1 ratio. Infrared thermography (IRT) will be used to assess the heat transport characteristics of the Heart and Lung meridians. The specificity for the meridian-visceral association will be investigated by comparing the difference in heat transport characteristic between the Heart and Lung meridians in the healthy control group and COPD group. Meanwhile, moxibustion will be given to subjects in the Heart meridian and Lung meridian respectively in the healthy intervention group to verify the specificity for the surface-surface association.

RESULTS

The primary outcomes will be the temperature of corresponding sites along the Heart and Lung meridians.

CONCLUSION

This study will verify the specificity between different meridians by comparing the difference in heat transport characteristic. The findings will guide the selection of acupoints to optimize the therapeutic effect of acupuncture and help determine whether IRT could be used to assist in the diagnosis of COPD.

ETHICS AND DISSEMINATION

The study has been approved by the Third Affiliated Hospital of Zhejiang Chinese Medical University (Approval No. ZSLL-KY-2019-001G-01).

TRIAL REGISTRATION NUMBERS

NCT04046588.

Recent Approaches on Signal Transduction and Transmission in Acupuncture: A Biophysical Overview for Medical Sciences

Acupuncture is one of the areas among the alternative therapies that arise high curiosity in the biomedical scientific community. It is particularly popular for treatment of chronic diseases and addictions. However, contrasting with its evidence-based effectiveness, the lack of reasonable explanations for its mode of action divides that scientific community. Difficulties also arise to those responsible for providing information for clinicians and professionals who wish to acquire competencies leading to the acupuncture practice and have a background based on biochemistry and physiology. The classic theories of nerve conduction do not fully explain how information is read and transmitted during the acupuncture treatment. Other theories have been proposed, but they are based on concepts such as biophotonic waves and quantum biochemistry that are difficult to read and understand by those who do not have knowledge in physics. It is the main objective of this review to provide a summary of the main theories and explanatory approaches to the signal transduction and conduction in acupuncture and to describe them in terms of their explanatory hypotheses, limitations, and weaknesses. The most of the literature found support theories for neural conduction, including gate control. They explain the effects of acupuncture in pain relief; few studies have been conducted concerning the conduction based on biophotons. The primo vascular system has been referred as a possible anatomic support for conduction of information during an acupuncture treatment, which could be connected to biophoton transmission.

Neuropeptides SP and CGRP Underlie the Electrical Properties of Acupoints

Electrical skin measurements at acupuncture points (acupoints) have been utilized as a diagnostic and therapeutic aid for more than 50 years. Although acupoints are described as having distinct electrical properties, such as high conductance and low impedance, the underlying mechanisms are currently unknown. The present study investigated in a rat model of hypertension whether the high conductance at acupoints is a result of the release of the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) during neurogenic inflammation in the referred pain area. When plasma extravasation from neurogenic inflammation was examined by exploring the leakage of intravenously injected Evans blue dye (EBD) to the skin, extravasated EBD was found most frequently in acupoints on the wrist. The increased conductance and temperature at these acupoints occurred during the development of hypertension. The increase in conductance and plasma extravasation at acupoints in hypertensive rats was ablated by cutting median and ulnar nerves, blocking small diameter afferent fibers with resiniferatoxin (RTX) injection into median and ulnar nerves, or antagonizing SP or CGRP receptors in acupoints. In turn, intradermal injection of SP or CGRP resulted in increased conductance and plasma extravasation in naïve rats. Elevated levels of SP and CGRP were found in the acupoints of hypertensive rats. These findings suggest that the high conductance at acupoints is due to vascular leakage following local release of SP and CGRP during neurogenic inflammation.

Reliability of skin impedance in subjects with chronic neck pain

BACKGROUND

Skin impedance is a biological signal that has been employed in the measurement of pain. However, there are few scientific data on skin impedance, with a great variety of assessment methods and controversial results.

OBJECTIVE

To examine the intra- and inter-rater reliability of skin impedance measurement in individuals with chronic neck pain.

METHODS

This is a blind cross-sectional study. Thirty individuals of both genders, aged between 18 and 45 years and with chronic neck pain were included in the study. Two examiners assessed skin impedance of the upper and lower limbs and torso at two intervals separated by one week. For statistical analysis, we used the intraclass correlation coefficient (ICC2,3) to determine the intra- and inter-rater reliability of skin impedance, with its respective confidence interval of 95%, standard error of measurement (SEM) and minimum detectable change (MDC).

RESULTS

The intra-rater reliability was considered substantial to excellent, with ICC values ranging between 0.843 and 0.978, SEM between 0.58 and 15.26 Ω, and MDC between 1.61 and 42.31 Ω. The inter-rater reliability was moderate to excellent, with ICC values ranging between 0.761 and 0.997, SEM ranging between 0.22 and 16.72 Ω, and MDC ranging between 0.63 and 46.35 Ω.

CONCLUSION

The measurement of skin impedance of the upper and lower limbs and torso in individuals with chronic neck pain has acceptable reliability values when considered at different times and by different examiners.

Acupuncture and Neural Mechanism in the Management of Low Back Pain-An Update

Within the last 10 years, the percentage of low back pain (LBP) prevalence increased by 18%. The management and high cost of LBP put a tremendous burden on the healthcare system. Many risk factors have been identified, such as lifestyle, trauma, degeneration, postural impairment, and occupational related factors; however, as high as 95% of the cases of LBP are non-specific. Currently, LBP is treated pharmacologically. Approximately 25 to 30% of the patients develop serious side effects, such as drowsiness and drug addiction. Spinal surgery often does not result in a massive improvement of pain relief. Therefore, complementary approaches are being integrated into the rehabilitation programs. These include chiropractic therapy, physiotherapy, massage, exercise, herbal medicine and acupuncture. Acupuncture for LBP is one of the most commonly used non-pharmacological pain-relieving techniques. This is due to its low adverse effects and cost-effectiveness. Currently, many randomized controlled trials and clinical research studies have produced promising results. In this article, the causes and incidence of LBP on global health care are reviewed. The importance of treatment by acupuncture is considered. The efforts to reveal the link between acupuncture points and anatomical features and the neurological mechanisms that lead to acupuncture-induced analgesic effect are reviewed.

Nonopioid Management of Neonatal Abstinence Syndrome

BACKGROUND

Current standard therapy for moderate to severe neonatal abstinence syndrome (NAS) includes opioid administration and often results in separation of mother and infant. Impaired maternal-infant bonding and extended neonatal opiate exposure may be associated with adverse developmental outcomes. Increased use of nonopioid adjunctive NAS therapies may decrease postnatal opioid exposure and length of stay (LOS), thereby promoting positive developmental outcomes for NAS-affected infants.

PURPOSE

To review the efficacy of rooming-in care and acupuncture as nonpharmacologic adjunctive agents to reduce the magnitude of postnatal opioid exposure and LOS.

METHODS

PubMed, Ovid Medline, Embase, and CINAHL databases were searched for primary studies on rooming-in care and acupuncture as adjunctive treatments for NAS; 8 are included in this review.

FINDINGS

Rooming-in care may decrease postnatal opioid exposure and LOS in NAS-affected infants. Acupuncture is safe in NAS patients; however, its definitive effect on narcotic use and length of hospitalization are inconclusive.

IMPLICATIONS FOR PRACTICE

Rooming-in care should be offered to NAS patients. Strong evidence does not exist to recommend acupuncture as a routine NAS treatment.

IMPLICATIONS FOR RESEARCH

Additional randomized clinical trials are necessary to assess the efficacy of acupuncture and to confirm the effect of rooming-in care on NAS outcomes, and delineate optimal elements of a rooming-in care model.

Altered Impedance of Ear Acupuncture Point MT2 in Breast Cancer Patients: A Preliminary Observation

Skin impedance at acupuncture points (APs) has been used as a diagnostic aid for more than 50 years. In this study, we have a diagnostic tool (JXT-2008) to measure the skin impedance of ear APs of 30 breast cancer patients and the corresponding skin impedance of ear APs of 30 healthy humans, and then we compared these changes in ear AP impedance in breast cancer patients and healthy individuals.

What is the Acupoint? A preliminary review of Acupoints

BACKGROUND

According to traditional Chinese medicine (TCM) theory, acupoints are specifically chosen sites of acupuncture manipulation, and also the basis for studying the mechanism of acupuncture. Stimulating different acupoints on the body surface could provide various therapeutic benefits. However, what is the acupoint? This question is not clear.

REVIEW SUMMARY

We focuse on examining the function of acupoints from different perspectives, including the local and the systemic effects of stimulating acupoints. For example, acupoints may release certain substances or incur some changes, which could adjust the function of organs, maintain homeostasis. Furthermore, the therapeutic effects of verum acupoints versus sham acupoints were discussed. However, due to insufficience in evidence and in current methodologies, research into mechanisms of acupuncture is still incomplete.

CONCLUSION

This review might explain, to some extent, what an acupoint is. Further research into the identity of acupoints is warranted, and multidisciplinary methods using novel technologies may yield significant advances over existing knowledge.

Do changes in electrical skin resistance of acupuncture points reflect menstrual pain? A comparative study in healthy volunteers and primary dysmenorrhea patients

Electrical skin resistance (ESR) measurements were performed with a four-electrode impedance detector at 10 points bilaterally on the first day of and the third day after menstruation in 48 healthy volunteers and 46 primary dysmenorrhea (PD) patients, to assess whether ESR changes of acupuncture points can reflect menstrual pain or not. The results showed statistical reductions in ESR imbalance ratio between left and right side that were detected at SP8 (Diji) and GB39 (Xuanzhong) (P < 0.05), and a statistical increase was detected at SP6 (Sanyinjiao) (P = 0.05) on the first day of menstruation compared with those values on the third day after menstruation in dysmenorrhea group. No significant differences were detected at other points within and between two groups (P > 0.05). This study showed that the imbalance of ESR at uterine-relevant points in PD patients is not significantly different from those of healthy women on both the 1st day of and the 3rd day after menstruation. The ESR imbalance ratio of certain points can either be lower or higher during menstruation in PD patients. The ESR property of acupuncture points needs to be investigated in further clinical trials with appropriate points, diseases, larger sample sizes, and optimal device.

Does changes in the electrical resistance of an acupuncture meridian predict pain intensity following orthopedic surgery?

Background

Several methods for assessment of severity of pain have been proposed but all of them are subjective.

Objectives

This study evaluated the association concerning changes in electrical resistance (ER) between two acupuncture points and severity of postoperative pain in order to define an objective measurement of pain.

Patients and Methods

In a cross-sectional study, 50 patients undergoing lower extremity orthopedic surgery with postoperative moderate to severe pain (VAS > 4,) were consecutively enrolled. In the recovery room, the patients' pain scores were assessed and in patients with VAS > 4, the electrical resistance between Li4 and Li11 acupuncture points as well as pain scores was measured prior and following analgesic administration.

Results

Following meperidine use, the mean VAS significantly decreased and the ER between the two acupoints was significantly increased. However, Pearson correlation analysis did not reveal any association between the trends of pain intensity and ER (P > 0.05). The ER change in patients operated under epidural anesthesia was significantly less than those who experienced general or spinal anesthesia.

Conclusions

There is a coincidence of pain relief and change in the ER of acupuncture meridians without significant association. The diagnostic value of ER for pain, stress response or any other physiologic outcome needs to be investigated in clinical trials with a well-defined control group, with more accurate instruments and probably in different acupuncture meridians.

Biophysical characteristics of meridians and acupoints: a systematic review

As an integral part of traditional Chinese medicine (TCM), acupuncture is a convenient and effective therapy with fewer adverse effects. Recently, researches on meridian essence have become core issues of modern TCM. Numerous experiments have demonstrated the objective existence of meridians by different technologies since 1950s, such as biophysics, biochemistry, and molecular biology. In this paper, we review biophysical studies on electric, acoustic, thermal, optical, magnetic, isotopic, and myoelectric aspects of meridians and acupoints. These studies suggest that meridians/acupoints have biophysical characteristics which are different from nonacupuncture points. Owing to the limitations of previous studies, future research using high-throughput technologies such as omics and multicenter randomized controlled trials should be performed to explore the acupuncture's mechanisms of action and demonstration of efficacy.

Research on nonlinear feature of electrical resistance of acupuncture points

A highly sensitive volt-ampere characteristics detecting system was applied to measure the volt-ampere curves of nine acupuncture points, LU9, HT7, LI4, PC6, ST36, SP6, KI3, LR3, and SP3, and corresponding nonacupuncture points bilaterally from 42 healthy volunteers. Electric currents intensity was increased from 0 μA to 20 μA and then returned to 0 μA again. The results showed that the volt-ampere curves of acupuncture points had nonlinear property and magnetic hysteresis-like feature. On all acupuncture point spots, the volt-ampere areas of the increasing phase were significantly larger than that of the decreasing phase (P < 0.01). The volt-ampere areas of ten acupuncture point spots were significantly smaller than those of the corresponding nonacupuncture point spots when intensity was increase (P < 0.05 ~ P < 0.001). And when intensity was decrease, eleven acupuncture point spots showed the same property as above (P < 0.05 ~ P < 0.001), while two acupuncture point spots showed opposite phenomenon in which the areas of two acupuncture point spots were larger than those of the corresponding nonacupuncture point spots (P < 0.05 ~ P < 0.01). These results show that the phenomenon of low skin resistance does not exist to all acupuncture points.

Development and evaluation of a novel four-electrode device system for monitoring skin impedance

Qi, meridians, and acupoints are important issues in Chinese medicine. One of the theories claims that acupuncture points and meridians have unique electrical properties. The associations between acupuncture points or meridians and special electrical properties are still under debate. In the current study, we introduced and explained a device for this kind of research and evaluated the reliability of this device as well as effects of pressure, cleaning the skin by alcohol and exfoliation on electrical skin measurements. Fifteen subjects (10 female, 5 male) were recruited to participate in the study. An impedance meter based on the four-electrode technique was designed and fabricated specifically for this study. The effects of pressure, cleaning of the skin by alcohol, and exfoliation on electrical skin impedance were evaluated separately. The device repeatability was also evaluated 30 times in a 30 minutes period. Scale weight up to 200 grams, cleaning the skin with alcohol, and exfoliation didn't affect the performance of this device. The device performance didn't change significantly during the 30 minutes measurement either. The new system we evaluated can be a reliable tool for researches on electrical skin impedance in acupuncture, as its performance is fairly stable even in the presence of various confounding factors such as various pressures on the probe, cleaning the skin with alcohol and exfoliation.

Role of neuropeptide Y in regulating hypothalamus-pituitary-gonad axis in the rats treated with electro-acupuncture

Neuropeptide Y (NPY) is an important regulator of reproductive axis, which mainly plays some roles in regulating secretion of gonadotropin-releasing hormone (GnRH) in hypothalamus. In previous studies, we found that the repeated low frequency electro-acupuncture (EA) down-regulated hypothalamus-pituitary-gonad (HPG) axis of common rats and rabbits during puberty. In this study, we investigated the role of NPY in regulating the reproductive axis of common rats at different developmental stages and rats treated with the repeated EA. Low frequency EA (3 Hz) was performed at acupoints (treatment groups) or non-acupoints (control groups) for 20 min daily for 10 days in Sprague-Dawley (SD) rats at four developmental stages, which were juvenile stage, early puberty stage, later puberty stage and adult stage. NPY expression in the hypothalamus were determined using RT-PCR and real-time quantitative PCR (qPCR) after 10 days-treatments. The results showed that NPY expression in the early pubertal group (EPG) was significantly depressed after repeated EA (P<0.05). Compared with the results of GnRH expression and body weights, the change of NPY expression was similar with the fluctuation of GnRH expression after EA and the increase of body weights of rats was not influenced by the depression of NPY expression after EA during early puberty. The results demonstrated that repeated low frequency EA was an effective method on down-regulating not only the GnRH expression but also the NPY expression in the hypothalamus without reducing body weights of rats during early puberty.

Impact of Surgical Intervention and Postoperative Pain on Electrical Skin Resistance at Acupuncture Points: An Exploratory Study

Objectives

One theory about acupuncture suggests that pathological processes can cause measurable changes in electrical skin resistance (ESR) at acupuncture points (APs). Although the theory has yet to be proven, ESR measurements (ESRMs) form a frequently used part of contemporary acupuncture. The aim of this study was to test the so-called ‘electrical responsiveness’ of APs in the setting of a defined operative trauma.

Methods

ESRMs (n=424) were performed at the APs and surrounding skin of GB34 and ST38 in 163 participants using an impedance meter array developed for the purpose of ESRMs. For each group the percentage of measurements with a significantly different ESR between the APs and the surrounding skin was calculated and compared with each other. Measurements of four groups were compared: healthy control subjects (n=30) and patients after ophthalmic (n=29), hip (n=42) and shoulder (n=30) surgery. The influence of postoperative pain intensity was also assessed.

Results

Group comparison showed no significant differences for ST38. The ESRMs at GB34 had a significantly higher percentage of measurements with an increased ESR after ophthalmic (23.2%) and hip (22.2%) surgery, but not after shoulder surgery (7.5%). Subgroup analysis showed that an increase in pain intensity tended to lead to a decrease in the number of APs with ESR changes.

Conclusion

These results suggest that reactive changes in ESR at APs might exist. Pain and alertness seem to have an impact on ESR at APs. However, the current data do not allow for conclusions to be drawn concerning the clinical use of ESRMs.

A comparison of the hypoalgesic effects of transcutaneous electrical nerve stimulation (TENS) and non-invasive interactive neurostimulation (InterX(®)) on experimentally induced blunt pressure pain using healthy human volunteers

OBJECTIVES

Non-invasive interactive neurostimulation (InterX(®)) delivers high amplitude electrical pulsed currents at points of low impedance on the skin. This study compared the hypoalgesic effect of non-invasive interactive neurostimulation with transcutaneous electrical nerve stimulation (TENS).

MATERIALS AND METHODS

A repeated measures parallel group study on healthy human volunteers randomized to receive strong non-painful TENS or non-invasive interactive neurostimulation for 21 min on the forearm (N= 10/group). Pressure algometry was used to determine blunt pressure pain threshold at baseline, 10, and 20 min during stimulation, and 5 min post stimulation.

RESULTS

Low impedance sites were found in half of the participants receiving non-invasive interactive neurostimulation. ANOVA found no effects for intervention (p= 0.923), time × intervention interaction (p= 0.21), or time (p= 0.094).

CONCLUSIONS

Given the limited power of this study, we show that there were no significant differences in hypoalgesia between non-invasive interactive neurostimulation and TENS. Unlike our previous studies we also failed to detect a change pain threshold during TENS. Nevertheless, our findings can be used to inform the design of an appropriately powered study on pain patients.

Reliability of AcuGraph system for measuring skin conductance at acupoints

OBJECTIVE

There are many commercially available instruments for measuring electrical conductance, but there is little information about their reliability. The aim of this study was to quantify measurement variability and assess reliability of the AcuGraph system-a commonly used electrodermal screening device.

METHODS

Four experiments were conducted to measure variability in electrical conductance readings obtained by the AcuGraph system. The first involved measuring known resistors. The second measured non-human organic matter. The third was a test-retest assessment of the Yuan-Source and Jing-Well points in 30 healthy volunteers who were measured by a single operator. The fourth was an interoperator reliability evaluation of seven acupuncturists at the Yuan-Source and Jing-Well acupoints on four individuals at two time points.

RESULTS

Against known resistors, the AcuGraph had an average coefficient of variability (CV) of 1.8% between operators and test-retests. On non-human organic material the AcuGraph had an average CV of 0.9% and 2.8%. When a single operator tested 30 participants, the average reliability for the Yuan-Source points was 0.86 and 0.76 for Jing-Well points with a CV of 23.2% and 25.9% respectively. The average CV for the seven acupuncturists was 24.5% on Yuan-Source points and 23.7% on Jing-Well points.

CONCLUSIONS

The AcuGraph measures known resistors and organic matter accurately and reliably. Skin conductance at acupoints recorded by one operator was also reliable. There was less consistency in electrodermal recordings obtained by seven different operators. Operator training and technical improvements to the AcuGraph may improve consistency among operators.

Biomedical engineering meets acupuncture--development of a miniaturized 48-channel skin impedance measurement system for needle and laser acupuncture

Background

Due to controversially discussed results in scientific literature concerning changes of electrical skin impedance before and during acupuncture a new measurement system has been developed.

Methods

The prototype measures and analyzes the electrical skin impedance computer-based and simultaneously in 48 channels within a 2.5×3.5 cm matrix. Preliminary measurements in one person were performed using metal needle and violet laser (405 nm) acupuncture at the acupoint Kongzui (LU6). The new system is an improvement on devices previously developed by other researchers for this purpose.

Results

Skin impedance in the immediate surroundings of the acupoint was lowered reproducibly following needle stimulation and also violet laser stimulation.

Conclusions

A new instrumentation for skin impedance measurements is presented. The following hypotheses suggested by our results will have to be tested in further studies: Needle acupuncture causes significant, specific local changes of electrical skin impedance parameters. Optical stimulation (violet laser) at an acupoint causes direct electrical biosignal changes.

A multichannel system for continuous measurements of skin resistance and capacitance at acupuncture points

Electrodermal screening (EDS) is based on three commonly held assumptions: acupuncture points (APs) have lower electrical resistance than non-APs; resistance at APs varies with health and disease; and effective acupuncture treatments are associated with normalization of resistance at APs. Although evidence confirming these assumptions is limited, EDS is frequently practiced worldwide. Researchers are also beginning to assess EDS' utility as an outcome measure in acupuncture trials. Fundamental in developing EDS as a research tool is the need for an accurate and reliable measurement. We developed an automated multichannel prototype system, the Octopus, and recorded electrical resistance and capacitance at eight skin sites in 33 healthy participants over 2 hours. The Octopus accurately measured against known resistors (within 2.5% of the mean value) and capacitors (within 10% of the mean value), and yielded repeatable readings at all eight skin sites: LR 1 (r=0.79), SP 1 (r=0.79), toe non-AP (r=0.77), LU 9 (r=0.97), PC 6 (r=0.96), wrist non-APs (r=0.97), SP 6 (r=0.96), and leg non-APs (r=0.97). Resistance at APs was significantly lower than the nearby non-APs in one out of three comparisons.

Immediate effect of electric point stimulation (TENS) in treating latent upper trapezius trigger points: a double blind randomised placebo-controlled trial

OBJECTIVE

The purpose of this study was to investigate the immediate effect of electric point stimulation in treating latent upper trapezius trigger points compared to placebo.

DESIGN

Double blind randomised placebo-controlled trial.

SETTING

Anglo-European College of Chiropractic.

PARTICIPANTS

Sixty participants with latent upper trapezius trigger points.

INTERVENTIONS

Electric point stimulator type of TENS, or detuned (inactive) electric point stimulator type of TENS.

MAIN OUTCOME MEASURES

The three outcome measures were pressure pain threshold at the trigger point, a numerical rating scale for pain elicited over the trigger point, and lateral cervical flexion to the side opposite the trigger point.

RESULTS

On the outcome of pressure pain threshold the electric point stimulator group had a mean change of 0.49 (0.99) kg/cm(2), while the placebo group had a mean change of 0.45 (0.98) kg/cm(2) (t = 0.16, df = 58, p = 0.88). For change in pain over the trigger point, the electric point stimulator group had a mean decrease of 0.93 (0.87) points, while the placebo group had a mean decrease of 0.23 (0.97) points (t = 0.70, df = 58, p = 0.005). On the outcome of change in lateral cervical flexion the electric point stimulator group had a mean increase of 2.87 (4.55) degrees, while the placebo group had a mean increase of 1.99 (2.49) degrees (t = 0.92, df = 58, p = 0.36).

CONCLUSION

Electric point stimulator type of TENS is superior to placebo only in reduction of pain for treating latent upper trapezius trigger points.