Physical basis of acupuncture

Popularity of acupuncture is boosted by a seemingly well-looking ancient Chinese medical system. However, what is behind a mysterious system of acupuncture points and meridians? Several decades ago, we were systematically searching for the most promising areas where alternative medicine and spiritual domains could meet hard science. Finally, acupuncture was chosen as one of the most promising topics. Thus, from 2006 to 2016 we have undertaken a discovering journey into physical bases of acupuncture. From our first hand experience by diverse measurements, as well as attendance of International congresses of medical acupuncture, I currently perceive acupuncture quite differently compared to the time when I was starting this research. I’ve found a number of inconsistencies together with new explanations, that changed my view on acupuncture dramatically.

It is a generally held belief within the acupuncture community that acupuncture points and meridians structures are special conduits for electrical signals. In a systematic review of the electrical properties of acupuncture points and meridians from 2008 it is stated that any consistent anatomical structure or function for either acupuncture points or meridians was not established. Examinations on humans to determine whether electrical conductivity was significantly different near meridians than other places in the body have been inconclusive so far. This was exactly our starting point, where we began our research. We could rely on the support and exploitation of the equipment and infrastructure of the Institute of Measurement Science of the Slovak Academy of Sciences.

Experiences from our research suggest that there need not necessarily exist any special structures like acupuncture points or meridian with a flow of mysterious qi energy. Instead of searching for physical, anatomical or physiological correlates, the search for the explanation of how acupuncture works should be at least partly redirected to the power of placebo effect, art of physiotherapy, and a sort of wholistic understanding of the body functioning.

We haven’t investigated the clinical effectiveness of acupuncture. In our region, there is rich anecdotal evidence of (at least short-term) successful treatments by acupuncture for a wide spectrum of conditions. However, many of them are chronic or having a psychosomatic nature.

In these cases, the placebo effect might be enhanced by a mix of long-lasting Chinese medicine tradition, a sort of impressive appearance of acupuncture needles, and their invasive intervention that is to be felt. Moreover, the professional appearance of the acupuncturist and his or her way of communicating with the patient seems to be another key factor for the beneficial outcome of the treatment. However, real physiological effects (besides those caused by placebo) are not ruled out: Penetration of the needles together with their manipulation causes irritation and starts a series of events within the central nervous system. Consequently, extended reactions might include the release of endorphins which can contribute to pain relief. The remaining hope to save acupuncture’s reputation is to explain acupuncture points as locations with a higher concentration of nerve endings, causing more effective brain stimulation, which in turn can release biochemical substances back to various parts of the body.

Our findings don’t directly falsify acupuncture treatment proficiency. However, thousands of papers had been published on the efficacy of acupuncture for the treatment of various adult health conditions, but there was no robust evidence it was beneficial for any conditions, except shoulder pain and fibromyalgia. For example, in Germany, public health insurers began to cover acupuncture for chronic low back pain and osteoarthritis of the knee, but not tension headache or migraine. Some modern practitioners support the use of acupuncture to treat pain, but have abandoned the use of qi, meridians, yinyang and other mystical terms as an explanatory framework.

Final verdict: It probably doesn’t take any revolutionary discoveries in physics, medicine, or physiology to explain how acupuncture does or doesn’t work.


In the next part we present a sample of our research work originating from a conference contribution in order to illustrate our research approach. At the end, there is a list of our papers and conference contributions.

During our attempt for the characterization of acupuncture points and meridians, we have applied a number of measurement settings (Figs. 1-3):

Figure 1: Integral measurement means a multichannel data acquisition with a signal from each acupuncture point. Use of adhesive disposable Ag/AgCl ECG electrodes.
Figure 2: Invasive measurement in kHz range by application of acupuncture needles.
Figure 3: Invasive measurement with needles. Left: using instrument measuring in the low radio frequency range. Right: Auricular acupunture with needles inserted into the earlobe (project with University of Greifswald, Germany)

Impedance maps of acupuncture points

Michal Teplan, Marek Kukučka, Alena Ondrejkovičová, Boris Ivanič


In acupuncture and related fields, it is assumed that there are special pathways in the body called meridians which are connected to main body systems, such as cardiovascular, respiratory, digestive, etc. In this concept, the pathways are exposed to the surface of the human body in so-called acupuncture points localized on the skin surface. Although the application of acupuncture is relatively well established in Western medicine as a complementary therapeutic tool, its physical and medical characterization is still largely unknown. Some of the previous studies showed that electrical characteristics like impedance and capacitance may show distinct values at acupuncture points in comparison to values obtained from surrounding non-acupuncture points. Acupuncture sites were found to possess lower impedance and higher electrical capacity. However, some studies found no distinction from surrounding tissues.


A systematic review by Ahn et al. stated that it is still impossible to determine whether acupuncture structures possess distinct electrical characteristics until better-quality studies are performed [1]. Colbert [2] calls for precise replication of the historical study by Becker et al. [3]. 


Several subjects participated in this initial part of our study.

Methods and analysis

The first point was to replicate the experiment of Becker et al. [3] with improved measurement technology. Impedance maps were measured with a grid of 64 brass needle electrodes (Fig. 4). Their telescopic tips maintain balanced pressure across a measured area covering 17.5 mm x 17.5 mm. Distances between neighbouring tips are 2.5 mm. The monopolar arrangement was applied with a clamp reference electrode placed on the opposite arm (surface 6 cm2). Frequency 1 kHz was used for probing current. The unique recording system is controlled from a Matlab environment via a USB port. The device measures the voltage difference between active and reference electrodes based on spike detectors.

Figure 4: Brass needle electrodes with telescopic tips serving for mapping areas around acupuncture points.

Our second goal was to develop a new procedure that would be able to enhance the visualization of acupoints. We introduced the concept of differential maps: The experimental protocol includes impedance map measurements before, during, and after stimulation of the acupuncture system. Then subtraction of maps obtained during stimulation and that one obtained before stimulation is realized and differential maps are produced (Fig. 5, lower raw). Electro-acupuncture stimulation is used. Different frequencies for stimulation are chosen, according to desired excitation or inhibition.


Impedance maps from several subjects and 10 different acupoint locations from upper limbs did not consistently support the expected map structure with any typical characteristics. In most of the cases, distinctive minima surrounded by circular patterns were not found. Most of the maps comprised no strictly isolated depression in impedance modulus, however, in some cases there was an indication of it (Fig. 5, upper raw)[4]. Control maps taken from neighbouring sites showed irregular extremities spread across the measured skin surface as well. In several samples, acupoint was found as a region with increased impedance values. Samples of differential maps appear to show an improved distinction of impedance structures in the areas of acupuncture points (Fig. 5, lower raw).

Figure 5: Impedance maps of successfully localized acupuncture points PC-6, LU-5, and LI-4 (upper row). Procedure for enhanced visualization by means of electrical stimulation (lower row).


Our preliminary results show inconsistency in the localization of acupoints as surface structures with spatially distinct values of electrical impedance. The development of a new visualization procedure may enhance the detection of acupuncture points.


[1]: Ahn AC et al.: Electrical properties of acupuncture points and meridians: a systematic review. Bioelectromagnetics 29: 245-256, 2008.

[2]: Colbert A: The Ongoing Debate: Do Acupuncture Points Have Lower Skin Resistance Than Nonacupuncture Sites? The Journal of Alternative and Complementary Medicine 15 (10): 1059-1059, 2009.

[3]: Becker R et al.: Electrophysiological correlates of acupuncture points and meridians. Psychoenergetic Systems 1: 195-212, 1976.

[4] Teplan M, Kukučka M, Ondrejkovičová A: Impedance analysis of acupuncture points and pathways. Journal of Physics: Conference Series, vol. 329, 2011.

Our papers and conference contributions:

Teplan, M. – Kukučka, M. – Ivanič, B. – Ondrejkovičová, A.: Impedance maps of acupuncture points. ICMART 2013 – Conference of International Council of Medical Acupuncture and Related Techniques, Vienna, Austria, 2013 (poster). 

Usichenko, T. – Gogola, D. – Dermek, T. – Teplan, M.: Method for continuous multichannel measurement of impedance at the auricular sites innervated by various cranial nerves, In: Book of abstracts, 6th International Conference on Transcranial Brain Stimulation, Göttingen, Germany, p. 135, 2016 (poster).

Kukučka, M – Kozák, Š. – Weisze, A. – Ďuračková, D. – Stopjaková, V. – Krajčušková Z. – Teplan M.: Mechanical vs. Pneumatic Model of Measuring Probe in Voltage Acupuncture Skin Mapping, International Review of Automatic Control, Vol. 8, N. 6, 2015 .

Teplan, M. – Kukučka, M. – Ivanič, B. – Ondrejkovičová, A.: Impedančná analýza akupunktúrnych bodov. XXVII. Congressus acupuncturae Bohemiae et Slovaciae, Česká lékařská akupunkturistická společnost České lékařské společnosti J. E. Purkyně, Slovenská spoločnosť akupunktúry Slovenskej lekárskej spoločnosti, Znojmo, 2013.

Teplan, M. – Kukučka, M. – Ivanič, B. – Ondrejkovičová, A.: Impedance maps of acupuncture points. Invited lecture for “International academic salon Energetic medicine – natural therapy“, Beijing, China, 2013.  

Teplan, M. – Kukučka, M. – Ondrejkovičová, A.: Bioelectrical properties of human body, impedance analysis of acupuncture points. Mapping Time, Mind and Space – joint meeting between SMN and SSE, Termonfechin, Ireland, 2012 (presentation).

Teplan, M. – Kukučka, M. – Ondrejkovičová, A.: Impedance analysis of acupuncture points and pathways, Journal of Physics: Conference Series, vol. 329, 2011.

Teplan, M.: Akupunktúra: princípy, prístupy a perspektívy výskumu, 2009 (presentation in Slovak).