<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Tetra-polar electrical impedance measurement (TPIM) with a square geometry of electrodes is useful in the characterization of epithelial tissues, especially in the detection of cervical cancer at precancerous stages. However, in TPIM, the peak planar sensitivity just below the electrode surface is almost zero and increases to a peak value at a depth of about one third to one half of the electrode separation. To get high sensitivity for the epithelial layer, having thicknesses of 200 μm to 300 μm, the electrode separation needed is less than 1 mm, which is difficult to achieve in practical probes. This work proposes a conical conducting layer in front of a pencil like probe with a square geometry of TPIM electrodes to create virtual electrodes with much smaller separation at the body surface, thus increasing the sensitivity of the epithelial tissues. To understand the improvements, if any, 3D sensitivity distribution and transfer impedance were simulated using COMSOL Multiphysics software for a simplified body tissue model containing a 300 μm epithelial layer. It has been shown that fractional contribution of an epithelial layer can be increased several times placing a cylindrical conducting layer in between the tissue surface and the electrodes, which can further be enhanced using a conical conducting layer. The results presented in this paper can be used to choose an appropriate electrode separation, conducting layer height and cone parameters for enhanced sensitivity in the epithelial layer.</p></abstract>

Tetra-polar electrical impedance measurement (TPIM) with a square geometry of electrodes is useful in the characterization of epithelial tissues, especially in the detection of cervical cancer at precancerous stages. However, in TPIM, the peak planar sensitivity just below the electrode surface is almost zero and increases to a peak value at a depth of about one third to one half of the electrode separation. To get high sensitivity for the epithelial layer, having thicknesses of 200 μm to 300 μm, the electrode separation needed is less than 1 mm, which is difficult to achieve in practical probes. This work proposes a conical conducting layer in front of a pencil like probe with a square geometry of TPIM electrodes to create virtual electrodes with much smaller separation at the body surface, thus increasing the sensitivity of the epithelial tissues. To understand the improvements, if any, 3D sensitivity distribution and transfer impedance were simulated using COMSOL Multiphysics software for a simplified body tissue model containing a 300 μm epithelial layer. It has been shown that fractional contribution of an epithelial layer can be increased several times placing a cylindrical conducting layer in between the tissue surface and the electrodes, which can further be enhanced using a conical conducting layer. The results presented in this paper can be used to choose an appropriate electrode separation, conducting layer height and cone parameters for enhanced sensitivity in the epithelial layer.

Use of a conical conducting layer with an electrical impedance probe to enhance sensitivity in epithelial tissues

Journal of Electrical Bioimpedance

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Tetra-polar electrical impedance measurement (TPIM) with a square geometry of electrodes is useful in the characterization of epithelial tissues, especially in...

Use of a conical conducting layer with an electrical impedance probe to enhance sensitivity in epithelial tissues

Published Online: Dec 31, 2018

Page range: 176 - 183

Received: Dec 18, 2018

DOI: https://doi.org/10.2478/joeb-2018-0022

Keywords
Bioimpedance, Sensitivity, Epithelial tissue, virtual electrode, EIS, Impedance probe, conducting layer

© 2018 M.A. Kadir, K.S. Rabbani published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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Use of a conical conducting layer with an electrical impedance probe to enhance sensitivity in epithelial tissues

Published Online: Dec 31, 2018

Page range: 176 - 183

Received: Dec 18, 2018

DOI: https://doi.org/10.2478/joeb-2018-0022

KeywordsBioimpedance, Sensitivity, Epithelial tissue, virtual electrode, EIS, Impedance probe, conducting layer

© 2018 M.A. Kadir, K.S. Rabbani published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig.1

Fig. 2

Fig.3

Fig.4

Fig.5

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Fig.8

Fig.9

Fig.10

Keywords
Bioimpedance, Sensitivity, Epithelial tissue, virtual electrode, EIS, Impedance probe, conducting layer