110 GHz broadband measurement of permittivity on human epidermis using 1 mm coaxial probe

Hwang, Hyeonseok; Yim, Jounghwa; Cho, Jeiwon; Cheon, Changyul; Kwon, Youngwoo

doi:10.1109/mwsym.2003.1210961

Cited by 23 publications

(10 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Free spaces measurements are sensitive to the position of the hand, so a change of a small angle when placing the hand would influence the absolute value of the reflection. The absolute value of the skin reflection was measured by others [29,30]. Therefore we decided to use the hand signal itself as a baseline, taken when the subject is resting between CWT sessions.…”

Section: The Skin Reflectancementioning

confidence: 99%

The unexplored avenues of human skin: electromagnetic properties in the sub-THz band

Feldman¹,

Safrai²,

Ishai³

et al. 2012

SPIE Proceedings

View full text Add to dashboard Cite

Recent studies of the minute morphology of the skin by optical coherence tomography showed that the sweat ducts in human skin become helically shaped tubes in the Epidermis and are filled with an aqueous solution. When considered as entities embedded in a dielectric media, they resemble helical antennas. The spectral response obtained by our computer simulations coincides with the analytical prediction of antenna theory and support this hypothesis, if a fast enough current mechanism exists in the duct. In particular the strongest spectral response of the simulation was noted around the predicted frequencies (240 GHz and 380 GHz) for the respective normal and axial modes of the helical structure. Furthermore, circular dichroism of the reflected electromagnetic field is a characteristic property of such helical antennas and it was shown that it is indeed a characteristic of the simulation model. Fast proton hopping is posited as the current mechanism.Consequently experimental evidence is presented that the spectral response of the skin in the sub-Terahertz region is governed by the level of activity of the perspiration system. This in turn is moderated by the Sympathetic Nerve Response and is demonstrated by the correlation to physiological stress as manifested by the pulse rate and the systolic blood pressure. These physical relaxations are tonic in nature (lasting more than a minute). Could the phasic characteristic of emotional excitation also be evident in the reflection coefficient? By applying techniques borrowed from psychiatric science we hope to answer this point in our paper.

show abstract

Section: The Skin Reflectancementioning

confidence: 99%

The unexplored avenues of human skin: electromagnetic properties in the sub-THz band

Feldman¹,

Safrai²,

Ishai³

et al. 2012

SPIE Proceedings

View full text Add to dashboard Cite

show abstract

“…Many researchers have investigated the use of open-ended coaxial probe techniques to measure the complex permittivity of dielectric materialsin particular, the permittivity of biological tissue [1,2]. The open-ended coaxial probe has been commonly used in order to measure the dielectric properties of biological tissue over a wide band of radio and microwave frequencies [3][4][5]. The coaxial probe technique presents significant advantages in that it does not require tissue manipulation or pre-treatment of the sample, and, using the coaxial probe, the dielectric properties obtained through measurements can be directly integrated 0960-1317/06/010173+07$30.00 © 2006 IOP Publishing Ltd Printed in the UK with surgical and pathology equipment, such as a needle.…”

Section: Introductionmentioning

confidence: 99%

“…For the detection of small biological tissue samples, a lowcost micro-coaxial probe with an extremely small diameter is required [4]. Until now, most dielectric measurement experiments have been performed using a 1 mm diameter coaxial probe [4,5]. Although the cost of a 1 mm diameter coaxial probe attached to an SMA connector is high compared with the conventional coaxial probe (2 or 3 mm diameter), many researchers have used the 1 mm diameter coaxial probe in order to obtain more precise dielectric information.…”

Section: Introductionmentioning

confidence: 99%

In vitromeasurement using a MEMS probe array with five-strip lines for permittivity measurement

Kim

Baek

et al. 2005

J. Micromech. Microeng.

View full text Add to dashboard Cite

This paper describes a single-aperture MEMS probe and a MEMS probe array for the measurement of biological properties. We designed and fabricated the single-aperture MEMS probe using surface micromachining and verified it by measuring the permittivity of a standard liquid before introducing the MEMS probe array. The actual aperture size of the single-aperture MEMS probe is only 390 µm × 80 µm, which is very small in comparison with the conventional laser-machined coaxial probe. In order to show the feasibility of the proposed single-aperture MEMS probe for permittivity measurements, we performed in vitro measurements of 0.9% saline. Once the single-aperture probe was verified, we proposed the concept of a probe array for biological measurements and experimentally showed the suitability of the MEMS probe array for biological applications through experiments using pork. The MEMS probe array consists of five microstrip feed lines, each of which is followed by open-ended strip lines, and the permittivity measurement of each port is separately performed through the use of a conventional multiport coaxial switch (Agilent, HP 87106 C), followed by a network analyzer (HP 8510 C). Through broadband measurements of 0.9% saline and pork using the MEMS probe array, we were able to discriminate the muscle and fat of pork through just one contact by placing the MEMS probe array on the boundary of muscle and fat. This newly proposed MEMS probe array has great potential in terms of disposability, low cost, integration with planar circuits and a short detection time for biological measurements.

show abstract

“…Other advancements in biological tissue characterization using open ended coaxial probes included broadband permittivity measurements of human epidermis (the epidermis: the outer skin layer) [28]. In this approach, a 1 mm diameter coaxial probe was used to help increase measurement bandwidth and to enhance the spatial resolution.…”

Section: Coaxial Probes For Biomedical Materials Characterizationmentioning

confidence: 99%

“…Additionally, when measuring the electrical properties of materials at high frequencies, the thickness of those being measured begin to influence the permittivity measurements if they are not chosen properly. In [28], it is recommended that the material under study be thicker (double) than the length of the probe to prevent it from influencing any permittivity measurements.…”

Section: Probe Integration Modeling With Unknown Materialsmentioning

confidence: 99%

Through Wafer 3D Vertical Micro-Coaxial Probe for High Frequency Material Characterization and Millimeter Wave Packaging Systems

Boone¹

View full text Add to dashboard Cite

110 GHz broadband measurement of permittivity on human epidermis using 1 mm coaxial probe

Cited by 23 publications

References 4 publications

The unexplored avenues of human skin: electromagnetic properties in the sub-THz band

The unexplored avenues of human skin: electromagnetic properties in the sub-THz band

In vitromeasurement using a MEMS probe array with five-strip lines for permittivity measurement

Through Wafer 3D Vertical Micro-Coaxial Probe for High Frequency Material Characterization and Millimeter Wave Packaging Systems

Contact Info

Product

Resources

About