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Article
Publication date: 19 January 2015

C.L. Yang, A. Mohammed, Y Mohamadou, T. I. Oh and M. Soleimani

The aim of this paper is to introduce and to evaluate the performance of a multiple frequency complex impedance reconstruction for fabric-based EIT pressure sensor…

Abstract

Purpose

The aim of this paper is to introduce and to evaluate the performance of a multiple frequency complex impedance reconstruction for fabric-based EIT pressure sensor. Pressure mapping is an important and challenging area of modern sensing technology. It has many applications in areas such as artificial skins in Robotics and pressure monitoring on soft tissue in biomechanics. Fabric-based sensors are being developed in conjunction with electrical impedance tomography (EIT) for pressure mapping imaging. This is potentially a very cost-effective pressure mapping imaging solution in particular for imaging large areas. Fabric-based EIT pressure sensors aim to provide a pressure mapping image using current carrying and voltage sensing electrodes attached on the boundary of the fabric patch.

Design/methodology/approach

Recently, promising results are being achieved in conductivity imaging for these sensors. However, the fabric structure presents capacitive behaviour that could also be exploited for pressure mapping imaging. Complex impedance reconstructions with multiple frequencies are implemented to observe both conductivity and permittivity changes due to the pressure applied to the fabric sensor.

Findings

Experimental studies on detecting changes of complex impedance on fabric-based sensor are performed. First, electrical impedance spectroscopy on a fabric-based sensor is performed. Secondly, the complex impedance tomography is carried out on fabric and compared with traditional EIT tank phantoms. Quantitative image quality measures are used to evaluate the performance of a fabric-based sensor at various frequencies and against the tank phantom.

Originality/value

The paper demonstrates for the first time the useful information on pressure mapping imaging from the permittivity component of fabric EIT. Multiple frequency EIT reconstruction reveals spectral behaviour of the fabric-based EIT, which opens up new opportunities in exploration of these sensors.

Details

Sensor Review, vol. 35 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 7 September 2012

A. Yao and M. Soleimani

Electrical impedance measurement and imaging are techniques that are widely used in a range of applications. Electro‐conductive knitted structure is a major new…

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1045

Abstract

Purpose

Electrical impedance measurement and imaging are techniques that are widely used in a range of applications. Electro‐conductive knitted structure is a major new development in wearable computing. The purpose of this paper is to carry out a preliminary investigation of applying electrical impedance analysis to predict the behavior of electro‐conductive knitted structure. This can potentially pave the way for a low‐cost solution for pressure mapping imaging.

Design/methodology/approach

Electrical impedance tomography (EIT) has been used as a mapping technique for deformation imaging in conductive knitted fabric. EIT is an imaging system used to generate a map of electrical conductivity. Pressure and deformation mapping scanner is being developed based on electrical conductivity imaging of the conductive area generated in a fabric. The results are presented using these new sensors with various deformations.

Findings

Experimental results show the feasibility of qualitative deformation imaging. In particular, it is promising that multiple deformations can be mapped using the proposed technique. The paper also demonstrates preliminary results regarding quantitative pressure and deformation mapping using EIT technique.

Research limitations/implications

The results presented in the paper are laboratory‐based experiments for proof of principle and will be evaluated in specific application areas in future.

Originality/value

The paper shows, for the first time, detection of multiple pressure points as well as quantifying the pressure map using the new imaging sensor. The sensor proposed here can be used for robotic touch sensing application, as well as some biomechanical observations.

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Article
Publication date: 9 November 2012

J. Hoła, Z. Matkowski, K. Schabowicz, J. Sikora, K. Nita and S. Wójtowicz

This paper aims to present a new non‐destructive method of brick wall dampness testing in real building structures. The electrical impedance tomography (EIT) method makes…

Abstract

Purpose

This paper aims to present a new non‐destructive method of brick wall dampness testing in real building structures. The electrical impedance tomography (EIT) method makes it possible to obtain a distribution of wall dampness. The paper aims to give basic information about the measuring system, including prototype equipment. The setup was used to determine the dampness of test brick walls on a specially built laboratory test rig. The paper seeks to compare test results obtained by the non‐destructive impedance tomography method with the results obtained by the conventional destructive dry‐weight method.

Design/methodology/approach

The paper adopts a tomography approach to control humidity inside of the brick walls. In case of brick walls other nondestructive methods fields, for example, the ultrasonic tomography is useless. On the other hand the most popular dry‐weight method is strictly forbidden for historical buildings. As a forward solver, functionally graded material boundary element method was used.

Findings

The paper proves that diffuse tomography could provide reliable results with respect of humidity content inside the brick walls. This method could provide 3D humidity distribution inside of the brick walls.

Research limitations/implications

It is expected that the technique's impact will be limited to site inspection of building following floods or to evaluate older damp buildings.

Practical implications

The presented technique can eventually lead to much simpler, cheaper and more efficient evaluation of the moisture content in walls. This can revolutionize some procedures in civil engineering.

Social implications

The application has commercial potential and could result in more cost‐effective repair of old buildings, which has an economic impact on society.

Originality/value

The authors propose application of the diffuse tomography for nondestructive investigation of brick walls. According to the authors' best knowledge this is a novel approach.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 19 September 2016

Ziqiang Cui, Qi Wang, Qian Xue, Wenru Fan, Lingling Zhang, Zhang Cao, Benyuan Sun, Huaxiang Wang and Wuqiang Yang

Electrical capacitance tomography (ECT) and electrical resistance tomography (ERT) are promising techniques for multiphase flow measurement due to their high speed, low…

Abstract

Purpose

Electrical capacitance tomography (ECT) and electrical resistance tomography (ERT) are promising techniques for multiphase flow measurement due to their high speed, low cost, non-invasive and visualization features. There are two major difficulties in image reconstruction for ECT and ERT: the “soft-field”effect, and the ill-posedness of the inverse problem, which includes two problems: under-determined problem and the solution is not stable, i.e. is very sensitive to measurement errors and noise. This paper aims to summarize and evaluate various reconstruction algorithms which have been studied and developed in the word for many years and to provide reference for further research and application.

Design/methodology/approach

In the past 10 years, various image reconstruction algorithms have been developed to deal with these problems, including in the field of industrial multi-phase flow measurement and biological medical diagnosis.

Findings

This paper reviews existing image reconstruction algorithms and the new algorithms proposed by the authors for electrical capacitance tomography and electrical resistance tomography in multi-phase flow measurement and biological medical diagnosis.

Originality/value

The authors systematically summarize and evaluate various reconstruction algorithms which have been studied and developed in the word for many years and to provide valuable reference for practical applications.

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Article
Publication date: 8 October 2018

Tomasz Rymarczyk, Jan Sikora and Paweł Tchórzewski

The paper aims to present an innovative solution for evaluation study of the dampness level of walls and historical buildings.

Abstract

Purpose

The paper aims to present an innovative solution for evaluation study of the dampness level of walls and historical buildings.

Design/methodology/approach

Electrical tomography enables one to obtain a distribution pattern of wall dampness. The application of modern tomographic techniques in conjunction with topological algorithms will allow one to perform very accurate spatial assessment of the dampness levels of buildings. The proposed application uses the total variation, Gauss–Newton and level set method to solve the inverse problem in electrical tomography.

Findings

Research shows that electrical tomography can provide effective results in damp buildings. This method can provide 2D/3D moisture distribution pattern.

Research limitations/implications

The impact of this technique will be limited to inspection of the facility after floods or assessment of historical buildings.

Practical implications

The presented method could eventually lead to a much more effective evaluation of moisture in the walls.

Social implications

The solution has commercial potential and could result in more cost-effective monitoring of historical buildings, which have an economic impact on society.

Originality/value

The authors propose a system for imaging spatial moistness of walls and historic buildings based on electrical tomography and consisting of a measuring device, sensors and image reconstruction algorithms.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 January 1993

S.‐Y. HAHN, I.‐H. PARK, H.‐K. JUNG and J. SIKORA

In the shadow of X‐ray tomography and nuclear magnetic resonance tomography a new tomographic technique based on low‐frequency electric currents has been successfully…

Abstract

In the shadow of X‐ray tomography and nuclear magnetic resonance tomography a new tomographic technique based on low‐frequency electric currents has been successfully developed in the past decade. Impedance computed tomography (ICT), although it gives poor spatial resolution images, is unmatched in certain cases. Two different approaches to the sensitivity analysis are presented in this paper. The direct differentiation method has been applied, but the adjoint variable method has not been used in ICT reconstruction algorithms until now. Some problems associated with the adjoint variable method of sensitivity analysis are discussed. The new algorithm is compared with the direct differentiation approach.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 June 2000

A. Savini

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic…

Abstract

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Content available
Article
Publication date: 25 July 2019

Juliana Padilha Leitzke and Hubert Zangl

This paper aims to present an approach based on electrical impedance tomography spectroscopy (EITS) for the determination of water and ice fraction in low-power…

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608

Abstract

Purpose

This paper aims to present an approach based on electrical impedance tomography spectroscopy (EITS) for the determination of water and ice fraction in low-power applications such as autarkic wireless sensors, which require a low computational complexity reconstruction approach and a low number of electrodes. This paper also investigates how the electrode design can affect the reconstruction results in tomography.

Design/methodology/approach

EITS is performed by using a non-iterative method called optimal first order approximation. In addition to that, a planar electrode geometry is used instead of the traditional circular electrode geometry. Such a structure allows the system to identify materials placed on the region above the sensor, which do not need to be confined in a pipe. For the optimization, the mean squared error (MSE) between the reference images and the obtained reconstructed images was calculated.

Findings

The authors demonstrate that even with a low number of four electrodes and a low complexity reconstruction algorithm, a reasonable reconstruction of water and ice fractions is possible. Furthermore, it is shown that an optimal distribution of the sensor electrodes can help to reduce the MSE without any costs in terms of computational complexity or power consumption.

Originality/value

This paper shows through simulations that the reconstruction of ice and water mixtures is possible and that the electrode design is a topic of great importance, as they can significantly affect the reconstruction results.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 38 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 20 June 2016

Chiew Loon Goh, Ruzairi Abdul Rahim and Mohd Hafiz Fazalul Rahiman

The purpose of this paper is to conduct a review of types of tomographic systems that have been widely researched within the past 10 years. Decades of research on…

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432

Abstract

Purpose

The purpose of this paper is to conduct a review of types of tomographic systems that have been widely researched within the past 10 years. Decades of research on non-invasively and non-intrusively visualizing and monitoring gas-liquid multi-phase flow in process plants in making sure that the industrial system has high quality control. Process tomography is a developing measurement technology for industrial flow visualization.

Design/methodology/approach

A review of types of tomographic systems that have been widely researched especially in the application of gas-liquid flow within the past 10 years was conducted. The sensor system operating fundamentals and assessment of each tomography technology are discussed and explained in detail.

Findings

Potential future research on gas-liquid flow in a conducting vessel using ultrasonic tomography sensor system is addressed.

Originality/value

The authors would like to undertake that the above-mentioned manuscript is original, has not been published elsewhere, accepted for publication elsewhere or under editorial review for publication elsewhere and that my Institute’s Universiti Teknologi Malaysia representative is fully aware of this submission.

Details

Sensor Review, vol. 36 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 1 November 2000

Jaroslav Mackerle

Gives a bibliographical review of the finite element methods (FEMs) applied in biomedicine from the theoretical as well as practical points of view. The bibliography at…

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1334

Abstract

Gives a bibliographical review of the finite element methods (FEMs) applied in biomedicine from the theoretical as well as practical points of view. The bibliography at the end of the paper contains 748 references to papers, conference proceedings and theses/dissertations dealing with the finite element analyses and simulations in biomedicine that were published between 1985 and 1999.

Details

Engineering Computations, vol. 17 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

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