Simultaneous reconstruction of permittivity and conductivity using multi-frequency admittance measurement in electrical capacitance tomography

Zhang, Maomao; Soleimani, Masoud

doi:10.1088/0957-0233/27/2/025405

Cited by 47 publications

(34 citation statements)

References 19 publications

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“…Here, an 8-electrode CCERT mesh model according to the real data-acquired system is created with 456546 tetrahedrons. This simulation work was carried out by the in-house MATLAB based software adapted from our 3D ECT model [17]. The sensitivity matrix which links the change of boundary measurements and the conductivity change of each voxel can be then introduced.…”

Section: Methodology a Forward Problemmentioning

confidence: 99%

“…In the sensing region , based on the theory of complex-valued admittance measurement, the integral relation between the complex capacitance of one electrode-pair and the distribution of conductivity and permittivity can be demonstrated as [17]:…”

Section: Methodology a Forward Problemmentioning

confidence: 99%

“…Came up in 2013, capacitively coupled electrical resistivity tomography (CCERT) was developed as an alternative to the traditional electrical resistivity tomography (ERT) with the theory of capacitively coupled contactless conductivity detection (C 4 D) [16]. CCERT can also be regarded as an adaptation of electrical capacitance tomography (ECT) and ERT, where the reactance part of the complex-valued ECT is analyzed [17] , [18]. Driven by the time-harmonic exciting voltage, CCERT can image the conductivity distribution without direct contact between electrodes and conductive medium [19], [20].…”

Section: Introductionmentioning

confidence: 99%

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Spectral Capacitively Coupled Electrical Resistivity Tomography for Breast Cancer Detection

2020

IEEE Access

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Early detection of breast cancer is key for a better survival rate, so there are huge demands for a safe and reliable breast cancer screening method, which currently is not available. Earlier studies are showing that the impedance spectroscopy can be an effective discriminator for breast tumor against healthy tissues. Traditional electrical impedance tomography (EIT) has progressed well into clinical stages for such an application with some promising results. But EIT generally operates at low frequencies, ranging typically lower than 1 MHz. Previous research work has suggested that the important information on the tumor impedance spectra exists in the higher frequency domain. Thus, this work focuses on the introduction and the evaluation of a spectral capacitively-coupled electrical resistivity tomography (CCERT) for breast cancer diagnosis. Compared to the traditional EIT, CCERT can reach a much higher frequency domain producing the spectroscopic images in a broader range. This in turns offers improved discrimination of tumors against normal tissues via frequency difference imaging or spectral imaging as it is shown in this paper. Additionally, direct contact between the EIT electrodes and the surface of the body, which causes significant challenges and uncertainties in measured data, is avoided in CCERT inherently a contactless method. In this paper, a 3D in-silico model of the CCERT system is created and solved using the finite element method (FEM) to simulate the forward model for each frequency. The feasibility simulation analysis is conducted based on the existing clinical breast cancer data and a CCERT reconstruction. For the experimental verification, an 8-electrode laboratory phantom was tested with the excitation frequency ranging from 200 kHz to 13 MHz. The simulation and experimental results show the promising potential of this method for breast cancer imaging. The wide-range spectroscopic images provide better discrimination of tumors against healthy tissues through their spectral conductivity profile as well as the rate of changes in spectral conductivity images. INDEX TERMS Breast cancer diagnosis, capacitively coupled electrical resistivity tomography (CCERT), conductivity spectrum of bio-samples, multi-frequency tomography.

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Section: Methodology a Forward Problemmentioning

confidence: 99%

Section: Methodology a Forward Problemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Spectral Capacitively Coupled Electrical Resistivity Tomography for Breast Cancer Detection

2020

IEEE Access

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“…For special cases where the conductive fluid is regarded as an equivalent resistance/conductance and only the real part of the impedance is used, it is termed capacitively coupled electrical resistance tomography (CCERT) [ 1 ]. Compared with the conventional electrical resistance tomography (ERT) technique [ 5 , 6 ], the new CCEIT technique can not only avoid the drawbacks of contact measurement (such as electrochemical erosion, polarization and contamination of the electrodes), but also make use of the total impedance information of the gas–liquid two-phase flow [ 1 , 2 , 7 , 8 ]. So, it has received wide attention from researchers in the research field of industrial process tomography [ 1 , 2 , 3 , 4 , 8 , 9 , 10 , 11 ].…”

Section: Introductionmentioning

confidence: 99%

On the Performance of a Capacitively Coupled Electrical Impedance Tomography Sensor with Different Configurations

Jiang

Wang

et al. 2020

Sensors

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Capacitively coupled electrical impedance tomography (CCEIT) is a new kind of electrical resistance tomography (ERT) which realizes contactless measurement by capacitive coupling and extends traditional resistance measurement to total impedance measurement. This work investigates the performance of a CCEIT sensor with three different configurations, including the unshielded configuration, the shielded configuration A (the CCEIT sensor with the external shield) and the shielded configuration B (the CCEIT sensor with both the external shield and the radial screens). The equivalent circuit models of the measurement electrode pair of the CCEIT sensor with different configurations were developed. Additionally, three CCEIT prototypes corresponding to the three configurations were developed. Both the simulation work and experiments were carried out to compare various aspects of the three CCEIT prototypes, including the sensitivity distribution, the impedance measurement and the practical imaging performance. Simulation results show that shielded configurations improve the overall average sensitivity of the sensitivity distributions. Shielded configuration A contributes to improve the uniformity of the sensitivity distributions, while shielded configuration B reduces the uniformity in most cases. Experimental results show that the shielded configurations have no significant influence on the imaging quality of the real part of impedance measurement, but do make sense in improving the imaging performance of the imaginary part and the amplitude of impedance measurement. However, configuration B (with radial screens) has no significant advantage over configuration A (without radial screens). This work provides an insight into how shielding measures influence the performance of the CCEIT sensor, in addition to playing an important role in shielding unwanted noise and disturbances. The research results can provide a useful reference for further development of CCEIT sensors.

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“…To overcome the drawbacks resulted from the contact measurement principle of EIT, such as electrochemical erosion effect, polarization effect and contamination of the electrodes in industrial applications and electrode-skin contact impedance in medical applications, a lot of efforts have been made by researchers 5 , 6 . In 2013, the capacitively coupled contactless conductivity detection (C 4 D) technique was introduced to the EIT field and a capacitively coupled electrical resistance tomography was proposed 7 , 8 .…”

Section: Introductionmentioning

confidence: 99%

Capacitively Coupled Phase-based Dielectric Spectroscopy Tomography

Jiang

Soleimani

2018

Sci Rep

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Impedance imaging is an effective approach for non-intrusively reconstruct the distribution of dielectric parameters inside the region of interest. Most common form of impedance imaging is electrical impedance tomography (EIT), which requires direct contact with the medium via electrodes. In this work we present a novel impedance imaging using capacitive coupling which provides a contactless method, totally non-invasive and non-intrusive, by measuring the phase. There are less attentions in many prior works to the phase information of the voltage/current measurements. This work studies for the first time the capacitively coupled electrical phase spectroscopy for contactless dielectric parameter imaging. A 12-electrode capacitively coupled test phantom and a measurement system were used to obtain the phase measurements within a wideband frequency range from 200 kHz to 15 MHz. Background data with different conductivity levels were investigated in the experiments to show a broad application possibility. The forward modelling was implemented by simulation and the image reconstruction based on phase measurements was implemented with the total variation algorithm. The potentials, possibilities and challenges of such capacitively coupled dielectric spectroscopy tomography with phase data are discussed in this work.

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Simultaneous reconstruction of permittivity and conductivity using multi-frequency admittance measurement in electrical capacitance tomography

Cited by 47 publications

References 19 publications

Spectral Capacitively Coupled Electrical Resistivity Tomography for Breast Cancer Detection

Spectral Capacitively Coupled Electrical Resistivity Tomography for Breast Cancer Detection

On the Performance of a Capacitively Coupled Electrical Impedance Tomography Sensor with Different Configurations

Capacitively Coupled Phase-based Dielectric Spectroscopy Tomography

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