Towards Non-Invasive Diagnosis of Skin Cancer: Sensing Depth Investigation of Open-Ended Coaxial Probes

Cemanur Aydinalp; Sulayman Joof; Tuba Yilmaz

doi:10.3390/s21041319

Towards Non-Invasive Diagnosis of Skin Cancer: Sensing Depth Investigation of Open-Ended Coaxial Probes

Sensors ◽

10.3390/s21041319 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1319

Author(s):

Cemanur Aydinalp ◽

Sulayman Joof ◽

Tuba Yilmaz

Keyword(s):

Dielectric Properties ◽

Dielectric Property ◽

Measurement Error ◽

Skin Cancer ◽

Rapid Change ◽

Biological Tissues ◽

Tissue Heterogeneity ◽

Low Contrast ◽

Practical Applications ◽

Coaxial Probes

Dielectric properties of biological tissues are traditionally measured with open-ended coaxial probes. Despite being commercially available for laboratory use, the technique suffers from high measurement error. This prevents the practical applications of the open-ended coaxial probes. One such application is the utilization of the technique for skin cancer detection. To enable a diagnostic tool, there is a need to address the error sources. Among others, tissue heterogeneity is a major contributor to measurement error. The effect of tissue heterogeneity on measurement accuracy can be decreased by quantifying the probe sensing depth. To this end, this work (1) investigates the sensing depth of the 2.2 mm-diameter open-ended coaxial probe for skin mimicking material and (2) offers a simple experimental setup and protocol for sensing depth characterization of open-ended coaxial probes. The sensing depth characterized through simulation and experiments using two double-layered configurations composed to mimic the skin tissue heterogeneity. Three thresholds in percent increase of dielectric property measurements were chosen to determine the sensing depth. Based on the experiment results, it was concluded that the sensing depth was effected by the dielectric property contrast between the layers. That is, high contrast results in rapid change whereas low contrast results in a slower change in measured dielectric properties. It was also concluded that the sensing depth was independent of frequency between 0.5 to 6 GHz and was mostly determined by the material located immediately at the aperture of the probe.

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Towards Accurate Microwave Characterization of Tissues: Sensing Depth Analysis of Open-Ended Coaxial Probes with Ex Vivo Rat Breast and Skin Tissues

Diagnostics ◽

10.3390/diagnostics11020338 ◽

2021 ◽

Vol 11 (2) ◽

pp. 338

Author(s):

Cemanur Aydinalp ◽

Sulayman Joof ◽

Tuba Yilmaz

Keyword(s):

Dielectric Properties ◽

Dielectric Property ◽

Classification Accuracy ◽

Ex Vivo ◽

Error Source ◽

Aperture Diameter ◽

Depth Analysis ◽

Coaxial Probes ◽

Measurement Results ◽

Destructive Measurement

Dielectric properties of biological materials are commonly characterized with open-ended coaxial probes due to the broadband and non-destructive measurement capabilities. Recently, potential diagnostics applications of the technique have been investigated. Although the technique can successfully classify the tissues with different dielectric properties, the classification accuracy can be improved for tissues with similar dielectric properties. Increase in classification accuracy can be achieved by addressing the error sources. One well-known error source contributing to low measurement accuracy is tissue heterogeneity. To mitigate this error source, there is a need define the probe sensing depth. Such knowledge can enable application-specific probe selection or design. The sensing depth can also be used as an input to the classification algorithms which can potentially improve the tissue classification accuracy. Towards this goal, this work investigates the sensing depth of a commercially available 2.2 mm aperture diameter probe with double-layered configurations using ex vivo rat breast and skin tissues. It was concluded that the dielectric property contrast between the heterogeneous tissue components has an effect on the sensing depth. Also, a membrane layer (between 0.4–0.8 mm thickness) on the rat wet skin tissue and breast tissue will potentially affect the dielectric property measurement results by 52% to 84%.

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LOW-FREQUENCY DIELECTRIC PROPERTIES OF BIOLOGICAL TISSUES: A REVIEWWITH SOME NEW INSIGHTS

Transactions of the ASAE ◽

10.13031/2013.17142 ◽

1998 ◽

Vol 41 (1) ◽

pp. 173-184 ◽

Cited By ~ 97

Author(s):

W. Kuang ◽

S. O. Nelson

Keyword(s):

Dielectric Properties ◽

Low Frequency ◽

Biological Tissues

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Measurement error analysis in the determination of microwave dielectric properties using cavity reflection method

Ferroelectrics ◽

10.1080/00150199608223608 ◽

1996 ◽

Vol 176 (1) ◽

pp. 167-177 ◽

Cited By ~ 7

Author(s):

Matjaž Valant ◽

Danilo Suvorov ◽

SrečO Maček

Keyword(s):

Dielectric Properties ◽

Measurement Error ◽

Error Analysis ◽

Microwave Dielectric Properties ◽

Reflection Method ◽

Microwave Dielectric

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Patch resonator for non-invasive detection of dielectric property changes in biological tissues

Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation ◽

10.1109/aps.2012.6348800 ◽

2012 ◽

Cited By ~ 4

Author(s):

Tuba Yilmaz ◽

Robert Foster ◽

Yang Hao

Keyword(s):

Dielectric Property ◽

Biological Tissues ◽

Non Invasive ◽

Property Changes

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Mechanical and Dielectric Properties of Aligned Electrospun Fibers

Fibers ◽

10.3390/fib9010004 ◽

2021 ◽

Vol 9 (1) ◽

pp. 4

Author(s):

Blesson Isaac ◽

Robert M. Taylor ◽

Kenneth Reifsnider

Keyword(s):

Dielectric Properties ◽

Dielectric Property ◽

Electrospun Nanofibers ◽

Cold Drawing ◽

General Interest ◽

Electrospun Fibers ◽

Energy Storage Devices ◽

Electrospinning Technique ◽

Specific Strength ◽

Aligned Nanofibers

This review paper examines the current state-of-the-art in fabrication of aligned fibers via electrospinning techniques and the effects of these techniques on the mechanical and dielectric properties of electrospun fibers. Molecular orientation, system configuration to align fibers, and post-drawing treatment, like hot/cold drawing process, contribute to better specific strength and specific stiffness properties of nanofibers. The authors suggest that these improved, aligned nanofibers, when applied in composites, have better mechanical and dielectric properties for many structural and multifunctional applications, including advanced aerospace applications and energy storage devices. For these applications, most fiber alignment electrospinning research has focused on either mechanical property improvement or dielectric property improvement alone, but not both simultaneously. Relative to many other nanofiber formation techniques, the electrospinning technique exhibits superior nanofiber formation when considering cost and manufacturing complexity for many situations. Even though the dielectric property of pure nanofiber mat may not be of general interest, the analysis of the combined effect of mechanical and dielectric properties is relevant to the present analysis of improved and aligned nanofibers. A plethora of nanofibers, in particular, polyacrylonitrile (PAN) electrospun nanofibers, are discussed for their mechanical and dielectric properties. In addition, other types of electrospun nanofibers are explored for their mechanical and dielectric properties. An exploratory study by the author demonstrates the relationship between mechanical and dielectric properties for specimens obtained from a rotating mandrel horizontal setup.

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Polytetrafluoroethylene Films in Rigid Polyurethane Foams’ Dielectric Permittivity Measurements with a One-Side Access Capacitive Sensor

Polymers ◽

10.3390/polym13071173 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1173

Author(s):

Ilze Beverte ◽

Ugis Cabulis ◽

Sergejs Gaidukovs

Keyword(s):

Dielectric Properties ◽

Dielectric Permittivity ◽

Low Frequency ◽

Capacitive Sensor ◽

Polyurethane Foams ◽

Active Area ◽

Ptfe Film ◽

Practical Applications ◽

Permittivity Measurements ◽

The Impact

As a non-metallic composite material, widely applied in industry, rigid polyurethane (PUR) foams require knowledge of their dielectric properties. In experimental determination of PUR foams’ dielectric properties protection of one-side capacitive sensor’s active area from adverse effects caused by the PUR foams’ test objects has to be ensured. In the given study, the impact of polytetrafluoroethylene (PTFE) films, thickness 0.20 mm and 0.04 mm, in covering or simulated coating the active area of one-side access capacitive sensor’ electrodes on the experimentally determined true dielectric permittivity spectra of rigid PUR foams is estimated. Penetration depth of the low frequency excitation field into PTFE and PUR foams is determined experimentally. Experiments are made in order to evaluate the difference between measurements on single PUR foams’ samples and on complex samples “PUR foams + PTFE film” with two calibration modes. A modification factor and a small modification criterion are defined and values of modifications are estimated in numerical calculations. Conclusions about possible practical applications of PTFE films in dielectric permittivity measurements of rigid PUR foams with one-side access capacitive sensor are made.

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Low Resistivity Pay Carbonates: A Practical Approach to Quantify Water Saturation Using a Modified Archie's Model

10.2118/206096-ms ◽

2021 ◽

Author(s):

Ramsin Eyvazzadeh ◽

Abdullatif Al-Omair ◽

Majed Kanfar ◽

Achong Christon

Keyword(s):

Machine Learning ◽

Water Saturation ◽

Pore Space ◽

Learning Algorithms ◽

Machine Learning Algorithms ◽

Theoretical Research ◽

Low Contrast ◽

Practical Applications ◽

Low Resistivity ◽

New Models

Abstract A detailed description of a modified Archie's equation is proposed to accurately quantify water saturation within low resistivity/low contrast pay carbonates. The majority of previous work on low resistivity/low contrast reservoirs focused on clastics, namely, thin beds and/or clay effects on resistivity measurements. Recent publications have highlighted a "non-Archie" behavior in carbonates with complex pore structures. Several theoretical models were introduced, but new practical applications were not derived to solve this issue. Built upon previous theoretical research in a holistic approach, new models and workflows have been developed. Specifically, utilizing a combination of machine learning algorithms, nuclear magnetic resonance (NMR), core and geological data, field specific calibrated equations to compute water saturation (Sw) in complex carbonate formations are presented. Essentially, these new models partition the porosity into pore spaces and calculate their relative contribution to water saturation in each pore space. These calibrated equations robustly produce results that have proven invaluable in pay identification, well placement, and have greatly enhanced the ability to manage these types of reservoirs. This paper initially explains the theory behind the development of the analysis illustrating workflows and validation techniques used to qualify this methodology. A key benefit performing this research is the utilization of machine-learning algorithms to predict NMR derived values in wells that do not have NMR data. Several examples explore where results of this analysis are compared to dynamic testing, formation testing and laboratory measured samples to validate and demonstrate the utility of this new analysis.

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Bone permittivity and its effect on using ground-penetrating radar

Geophysics ◽

10.1190/geo2017-0128.1 ◽

2018 ◽

Vol 83 (1) ◽

pp. H1-H11

Author(s):

Blair B. Schneider ◽

Georgios Tsoflias ◽

Don W. Steeples ◽

Rolfe Mandel ◽

Jack Hofman

Keyword(s):

Dielectric Properties ◽

Dielectric Property ◽

Ground Penetrating Radar ◽

Relative Permittivity ◽

Water Saturation ◽

Mixing Models ◽

Bone Properties ◽

Animal Bone ◽

Bone Minerals ◽

Ground Penetrating

Ground-penetrating radar (GPR) is a powerful tool that is still being developed for archaeological investigations. We investigated the dielectric properties of mammoth bone and bone from modern bison, cow, deer, and elk as a proxy for applying GPR for detecting prehistoric animal remains. Sample dielectric properties (relative permittivity, loss factor, and loss-tangent values) were measured with an impedance analyzer over frequencies ranging from 10 MHz to 1 GHz. Bone-sample porosity, bulk density, water saturation, and volumetric water content of the specimens were also measured. The measured sample-relative permittivity values were then compared with modeled relative permittivity values using common dielectric-mixing models to determine which parameters control the best-fit predictions of relative permittivity of animal bone. We observe statistically significant dielectric-property differences among different animal fauna, as well as variation as a function of frequency. In addition, we determine that the relative permittivity values of 8–9 for similar minerals, such as apatite, are not suitable as a proxy for predicting animal bone properties. We estimate new relative permittivity values of 3–5 for dry animal bone minerals in the frequency range of 100–1000 MHz using these common dielectric-mixing models. We postulate that differences in bone microstructure contribute to dielectric-property variability.

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