Dielectric properties of human skin at an acupuncture point in the 50-75 GHz frequency range: A pilot study

Abstract

The reason for using acupuncture points as exposure sites in some applications of millimeter wave therapy has been unclear. Acupuncture points have been suspected to exhibit particular direct current (DC), low-frequency electrical and optical properties compared to surrounding skin. To assess if such a biophysical correlation could exist at millimeter wave frequencies used in the therapy, we investigated the dielectric properties of an acupuncture point on the forearm skin within the 50 -75 GHz range. These properties were compared with those of a neighboring ipsilateral control area and a corresponding contralateral control area. The complex reflection coefficient at the end of an open-ended rectangular waveguide loaded with a Teflon plug was measured with a vector network analyzer. A suitable model of the aperture admittance was used to calculate the dielectric properties of the skin at the measured spots. Statistical analyses were conducted with an ANOVA to compare the three sites. From these analyses, the dielectric properties of the acupuncture site were found to be somewhat different from those of surrounding non-acupuncture sites from 50 to about 61 GHz, in the case of the real part of the complex permittivity.

Electromagnetic Signatures of Human Skin in the Millimeter Wave Band 80-100 GHZ

“…The levels of emissivity and reflectivity are determined by the relative complex permittivity of a medium, and these have been measured for human skin in the microwave and MMW frequency bands at specific frequencies and over limited number of participants and measurement locations by using an open ended coaxial probe in contact with the human body [22,30,[41][42][43]. Due to the limited measured data, different theoretical models are often used to predict the relative complex permittivity of the skin, such as the Cole-Cole model and Debye model [43][44][45].…”

Millimeter‐wave emissivity as a metric for the non‐contact diagnosis of human skin conditions

“…A half‐space electromagnetic model of the human skin was therefore developed to determine the emissivity of healthy skin and skin having a variety of medical conditions. The reflection coefficients for healthy skin and skin with second degree burns over the band 26.5–40 GHz were taken from Gao and Zoughi [] with open‐ended coaxial probe data from Alekseev and Ziskin [], Egot‐Lemaire and Ziskin [], and Smulders []. Permittivity data were used from the parametric models such as the Cole‐Cole model and Debye model [Gabriel et al, ,; Wallace et al, ].…”

What is the Acupoint? A preliminary review of Acupoints

“…In addition to the skin resistance, other electrical properties at acupoints were also discussed. For example, unilateral manual stimulation of acupoints LU7 and Zhaohai ( KD6 ) triggers the increase of skin potential amplitude than no acupuncture group ; volt‐ampere (V‐A) characteristic of acupoints has the characteristics of both nonlinear and inertia, and changes obviously in the patients of heart disease or stomach diseases ; the skin dielectric property of PC4 is different from surrounding nonacupuncture sites in the 50–61 GHz range ; the electrical conductance of most acupoints on Heart Meridian were decreased after EA stimulation in 10 healthy volunteers and varied with pathogenesis . However, a recent review showed that the electrical properties of acupoints were in a condition of imbalance even they have the same name on the affected meridians located symmetrically on bilateral sides of the body .…”