The aim of this study was to investigate the traditional meridian theory using speckle laser blood flow scanning technology to observe microcirculation of the Hegu acupoint area after acupuncture stimulation on distant points. An observational study was conducted to observe the microvascular perfusion of Hegu (LI4) and control points after acupuncturing Quchi (LI11). Thirty healthy volunteers (mean age
In accordance with traditional chinese medicine (TCM), effective acupuncture could enhance people’s health by clearing main and collateral channels, thus allowing the body’s Yin and Yang to achieve a state of dynamic equilibrium. Usually, effective acupuncture is also called deqi acupuncture (arrival of Qi). Deqi/Qi arrival (with its uniquely human characteristics like Qigong and Yin-yang) is accepted by parts of the international academic community [
The physiological changes caused by acupuncture are multifaceted, they occur on different levels and are aimed at different targets. In previous studies, our group observed changes of microcirculation in Hegu (LI4), Neiguan (PC6), and Weizhong (UB40) areas after deqi acupuncture stimulation using laser Doppler perfusion imaging, and we found that there are 3 kinds of effects: on the acupoint areas, on meridians, and on the whole body [
In order to further test the results described above, an experiment was conducted at the Institute of Acupuncture and Moxibustion (China Academy of Chinese Medical Sciences), to observe the blood flow changes on the Hegu (LI4) acupoint after acupuncturing Quchi (LI11) using speckle laser blood flow scanning technology.
All participants gave informed consent. The experimental procedure was approved by the Ethics Committee of the Institute of Acupuncture and Moxibustion of China Academy of Chinese Medical Sciences. To avoid discrepancies in manipulation, all the acupuncture operations were performed by the same medical practitioner.
Thirty healthy volunteers (14 female, 16 male; mean age
Acupuncture stimulation was done manually, using single-use acupuncture needles (
Flow diagram of acupuncture and scanning.
The temperature of the lab was kept at 26°C, and the volunteers were asked to come into the room 5–10 mins ahead of schedule to adapt to the temperature. Then we marked point 1 (Sanjian, LI3), point 2 (Hegu, LI4), point 3 (Yangxi, LI5), point 4 (control point, located on the Large Intestine channel/meridian), and point 5 (control point, not located on the Large Intestine channel/meridian); see Figure
Marked points to be investigated.
The principle of speckle laser blood flow scanning technology is that the speckle (basically the spot of light emitted by the instrument) is formatted at the tissue surface, and the speckle will change with the moving particles (such as red blood cells). Then the information about perfusion distribution can be obtained by assessing the intensity of fluctuations. The instrument we used was a multi-point synchronization scanner Moor FLPI (Moor Instruments Ltd., Millwey, UK). Measurement parameters: scanning distance about 11 cm; sample interval 40 ms; flux time constant 0.5 s; total scanning time 20 min. For the exact procedure of the experiment, see Figure
Thirty sets of average data of the skin microvascular perfusion (Flux, in arbitrary units) were analyzed by Moor Full-field Laser Perfusion Single Point Review 2.1 (provided by Moor Instruments Ltd.), comparing the average values of the different periods (before, during, and after acupuncture).
Further, according to our past research results and to eliminate the systemic effects of acupuncture, we processed the first 4 groups of original data referenced with point 5 as a control point. The correction formula was as follows.
During acupuncture-before acupuncture of point 1–4/during acupuncture of point 5.
After acupuncture-during acupuncture of point 1–4/after acupuncture of point 5.
Paired
When analyzing the average of original skin microvascular perfusion, it was noted that the blood flow of the observation points was different, with a large data standard deviation. The highest level of skin blood flow area was on Sanjian (LI3) which is situated foremost on the finger, and the lowest was on Hegu (LI4).
The blood flow of the observed points was influenced by needling Quchi (LI11), however, the changes did not reach the level of statistical significance (see Table
Changing of skin microvascular perfusion (in arbitrary units) of different points before, during, and after needling homolateral Quchi (LI11) in experiment 1 (
Mean | Before | During | After |
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acupuncture | acupuncture | acupuncture | |
Sanjian (LI3) |
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Hegu (LI4) |
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Yangxi (LI5) |
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Point 4 |
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Point 5 |
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From the past research results we know that every kind of acupuncture stimulation—including shallow acupuncture, but also deqi acupuncture—can bring about systemic reactions and changes of microvascular perfusion. To eliminate this influence, the original data was processed using the correction method described above [
The ratio of skin microvascular perfusion of Points 1–4 referenced to Point 5 before acupuncture in the experiment.
Sanjian (LI3) | Hegu (LI4) | Yangxi (LI5) | Point 4 | Point 5 | |
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During acupuncture | 0.02 | 0.04 | 0.03 |
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After acupuncture | 0.04 | 0.56 | 0.03 |
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Comparing the ratio of microvascular perfusion of points 1–4, it showed that there was no significant difference (
This group of experiments focuses on the role of acupuncture on microvascular function.
Microvessels provide the environment for cell growth, thus having direct impact on the function of cells and tissues. The microcirculation directly participates in the flow present in tissue (cell, blood, lymph, and tissue fluid) and is considered as a breakthrough for researching meridian phenomenon and acupuncture mechanism. In 1988, Xiu et al. reported that after acupuncturing Chize (Lu5), the skin microvascular self-discipline movement frequency of Shaoshang (Lu11) remained unchanged while the amplitude increased by more than 60%. They concluded that acupuncture could regulate microcirculation such as the microvascular vasomotion [
For revealing the difference between acupoints and non-acupoints with regard to microcirculation, our group did a series of studies on skin microvascular perfusion after acupuncture stimulation using laser Doppler flowmetry, laser Doppler imaging, and laser speckle scanning technology [
In previous studies at our laboratory, all experiments were conducted by stimulating acupoints in the extremities to observe the blood flow of acupoints in the proximal end on the same channel/meridian. The current experiment was conducted by stimulating the proximal end point Quchi (LI11) to observe the blood flow on the lower end of the same extremity, at Hegu (LI4), Sanjian (LI3), Yangxi (LI5), and the control points. In the current experiment and past experiments, only one point was stimulated at a time. The results showed that the increase of blood flow in 3 related meridian acupoints after needling Quchi (LI11) was statistically significant compared with that in the control points. Especially the blood flow of the Hegu (LI4) acupoint obviously changed after acupuncturing the point Quchi (LI11).
These investigations are part of the project The influence of acupoints’ physical and chemical properties caused by acupuncture stimulation supported by the National Natural Science Foundation of China, Beijing and the Chinese Ministry of Science and Technology. The investigations are supported by Stronach Medical Group and the Department of Science of the City of Graz. The authors would like to thank Ingrid Gaischek, M.S., from the Medical University of Graz, for the valuable help in preparing the paper.