Development and Evaluation of a Novel Four-Electrode Device System for Monitoring Skin Impedance

Abstract

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.

Investigation of the Electrical Impedance of Acupuncture Points and Non-Acupuncture Points before and after Acupuncture, using a Four-Electrode Device

“…By applying age limits and using control points on the other side of each person's body, the effects of some confounding factors such as age and race on impedance were minimised. 28 We used a fourelectrode device which was designed and tested for this study. This device had just 12 probes, so only six points on each side of the body could be chosen; this was a limitation of our research.…”

“…31 However, some studies have shown that the whole or part of skin impedance varies in different races, depending on factors such as age, environment and race. 32 33 In another study, we examined some confounding factors such as environment, moisture and pressure of the probe on the skin, and concluded that these factors had no impact on the results; 28 we omitted known confounding factors such as age by setting an age limit. However, in this study, we used a 5 mm diameter probe.…”

“…According to the specific study for device reliability, the results were found to be repeatable in several measurements during a specific period of time. 28 Each selected point was allocated an identification number. The computer screen was positioned out of sight of the researcher and operator and it was not possible to manipulate the results of electrical skin impedance.…”

Design and Performance Evaluation of a Home-Based Automatic Acupoint Identification and Treatment System

“…Other inventors have also claimed to identify health problems using similar devices [21], but this function has been questioned by the scientific community [22]. Shima et al developed a four-electrode device system that enables stable measurement of electrical skin impedance in acupuncture [23]. Yang et al designed an acupoint recognition device by improving the acupoint electric resistance detection technique of the two-electrode method in combination with mechanical structure design and embedded control techniques [24].…”