Assessment of the Spatial Distribution of Moisture Content in Granular Material Using Electrical Impedance Tomography

This paper presents a method for the online determination of the spatial distribution of the moisture content in granular material. It might be essential for the monitoring and optimal control of, for example, drying processes. The proposed method utilizes Electrical Impedance Tomography (EIT). As an exemplary material for experimental research, the black chokeberry (Aronia melanocarpa) was used. The relationship between the electrical impedance of the chokeberry and its moisture content was determined for a wide range of frequencies (20 Hz–200 kHz). The EIT research consisted of both simulation and experimental investigation. Experimental studies of the spatial distribution of the moisture content were performed in a cylindrical vessel equipped with 8 electrodes circumferentially arranged. The voltage signal from the electrodes was acquired simultaneously using the data acquisition module. Due to the high impedance of the chokeberries, exceeding 109 Ω for the dried matter, extraordinary instrumentation was necessary to be applied. On the other hand, raw chokeberry was characterized by a several orders of magnitude lower impedance (103–104 Ω), especially for high frequencies. The wide range of the observed impedance was able to be measured owing to its use of the voltage stimulation instead of the current stimulation (which is most common for EIT). The image reconstruction problem was solved using an iterative Gauss–Newton algorithm and the EIDORS (Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software) package. The obtained results showed a satisfactory ability to localize an insufficiently dried part of the material. Prospective ways to improve the imaging quality are also discussed.

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Designing a bench for testing medically and technically an information and measuring system for multi-frequency electrical impedance tomography of human lungs

Eastern-European Journal of Enterprise Technologies ◽

10.15587/1729-4061.2021.237529 ◽

2021 ◽

Vol 4 (5(112)) ◽

pp. 27-40

Author(s):

Grayr Aleksanyan

Keyword(s):

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Experimental Studies ◽

Measuring System ◽

Dynamic Visualization ◽

Impedance Tomography ◽

Written Information ◽

Human Lungs ◽

Wide Range ◽

Conducting Research

This paper solves the problem of developing and creating multifunctional tools for conducting research into systems of multi-frequency electrical impedance tomography of human lungs. A test bench consisting of modern medical equipment, simulating pre-and postoperative environments to create conditions that are most similar to clinical ones, under which it is planned to operate multi-frequency electrical impedance tomography systems, was proposed and manufactured. This makes it possible to reduce significantly the time for approbation, testing, and elimination of practical inaccuracies and problems of clinical application of the developed medical and technical facilities. A positive result is achieved due to the possibility of forming new test plans with specified conditions and different levels of complexity. This enables enhancing the effectiveness of subsequent clinical tests on patients who are treated in a resuscitation unit or an intensive care unit. The operability of the bench is proved by the repeatability of obtained results of monitoring ventilation and perfusion for each examined person, the continuity of dynamic visualization of the breathing process, as well as a high degree of correlation of obtained values of differences of potentials with the readings of a bedside monitor of a patient. An information and measuring system of multi-frequency electric impedance tomography of human lungs, developed by the author earlier, was used as the EIT device. The EIT tests were performed for the frequency range of 50 kHz – 400 kHz at a current of 5 mA. All experimental studies involved volunteers who gave written information consent to participate in the tests. The results of the research show that the proposed bench can be used in practice to solve a wide range of scientific and applied problems in the field of electrical impedance tomography

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A MATLAB-Based Boundary Data Simulator for Studying the Resistivity Reconstruction Using Neighbouring Current Pattern

Journal of Medical Engineering ◽

10.1155/2013/193578 ◽

2013 ◽

Vol 2013 ◽

pp. 1-15 ◽

Cited By ~ 16

Author(s):

Tushar Kanti Bera ◽

J. Nagaraju

Keyword(s):

Electrical Impedance Tomography ◽

Boundary Data ◽

Electrical Impedance ◽

Optical Tomography ◽

Current Pattern ◽

Impedance Tomography ◽

Reconstruction Software ◽

Tomography Reconstruction ◽

Input Variables ◽

Solver Performance

Phantoms are essentially required to generate boundary data for studying the inverse solver performance in electrical impedance tomography (EIT). A MATLAB-based boundary data simulator (BDS) is developed to generate accurate boundary data using neighbouring current pattern for assessing the EIT inverse solvers. Domain diameter, inhomogeneity number, inhomogeneity geometry (shape, size, and position), background conductivity, and inhomogeneity conductivity are all set as BDS input variables. Different sets of boundary data are generated by changing the input variables of the BDS, and resistivity images are reconstructed using electrical impedance tomography and diffuse optical tomography reconstruction software (EIDORS). Results show that the BDS generates accurate boundary data for different types of single or multiple objects which are efficient enough to reconstruct the resistivity images for assessing the inverse solver. It is noticed that for the BDS with 2048 elements, the boundary data for all inhomogeneities with a diameter larger than 13.3% of that of the phantom are accurate enough to reconstruct the resistivity images in EIDORS-2D. By comparing the reconstructed image with an original geometry made in BDS, it would be easier to study the inverse solver performance and the origin of the boundary data error can be identified.

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Electrical Impedance Tomography (EIT)

Research Developments in Computer Vision and Image Processing - Advances in Computational Intelligence and Robotics ◽

10.4018/978-1-4666-4558-5.ch013 ◽

2014 ◽

pp. 235-273 ◽

Cited By ~ 5

Author(s):

Tushar Kanti Bera ◽

J. Nagaraju

Keyword(s):

Medical Imaging ◽

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Optical Tomography ◽

Body Part ◽

Imaging Modalities ◽

X Rays ◽

Science And Engineering ◽

Impedance Tomography ◽

Anatomy And Physiology

Looking into the human body is very essential not only for studying the anatomy and physiology, but also for diagnosing a disease or illness. Doctors always try to visualize an organ or body part in order to study its physiological and anatomical status for understanding and/or treating its illness. This necessity introduced the diagnostic tool called medical imaging. The era of medical imaging started in 1895, when Roentgen discovered the magical powerful invisible rays called X-rays. Gradually the medical imaging introduced X-Ray CT, Gamma Camera, PET, SPECT, MRI, USG. Recently medical imaging field is enriched with comparatively newer tomographic imaging modalities like Electrical Impedance Tomography (EIT), Diffuse Optical Tomography (DOT), Optical Coherence Tomography (OCT), and Photoacaustic Tomography (PAT). The EIT has been extensively researched in different fields of science and engineering due to its several advantages. This chapter will present a brief review on the available medical imaging modalities and focus on the need of an alternating method. EIT will be discussed with its physical and mathematical aspects, potentials, and challenges.

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Design and Validation of a New Programmable Current Source for Electrical Impedance Tomography Applications

Sensor Letters ◽

10.1166/sl.2019.4135 ◽

2019 ◽

Vol 17 (9) ◽

pp. 688-695

Author(s):

Ramesh Kumar ◽

Sharvan Kumar ◽

A. Sengupta

Keyword(s):

Image Reconstruction ◽

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Current Source ◽

Reconstruction Algorithm ◽

Simulation Software ◽

Constant Current ◽

Impedance Tomography ◽

Constant Current Source ◽

Wide Range

This paper proposed an advanced digital voltage-controlled multi-frequency based constant current source, which is a wide range of loads and high SNR ratio for Electrical Impedance Tomography (EIT) application. In EIT a constant current source is required for injecting a sinusoidal current pulse to the phantom boundary. The boundary potentials are measured by inserting content current from the phantom boundary according to the variation in frequency and current levels. For studying the wide range of tissue conductivity among different type of subjects (the multi-frequency scanning) is desired in medical Electrical impedance tomography. The proposed Current source, which shows that the simulation has good performance at multi-frequency range with accuracy and stability. In proteus simulation software, the results show that the proposed circuit presents a more stable impedance output and the obtained boundary data at multi-frequency for the validation of the obtained data has been shown using suitable image reconstruction algorithm and is found suitable for image reconstruction much easier.

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Electrical Impedance Tomography (EIT)

Medical Imaging ◽

10.4018/978-1-5225-0571-6.ch004 ◽

2017 ◽

pp. 71-114 ◽

Cited By ~ 1

Author(s):

Tushar Kanti Bera ◽

J. Nagaraju

Keyword(s):

Medical Imaging ◽

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Optical Tomography ◽

Body Part ◽

Imaging Modalities ◽

X Rays ◽

Science And Engineering ◽

Impedance Tomography ◽

Anatomy And Physiology

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Survey on Medical Imaging of Electrical Impedance Tomography (EIT) by Variable Current Pattern Methods

Journal of ISMAC - June 2019 ◽

10.36548/jismac.2021.2.002 ◽

2021 ◽

Vol 2 (2) ◽

pp. 82-95

Author(s):

Edriss Eisa Babikir Adam ◽

Sathesh

Keyword(s):

Image Reconstruction ◽

Medical Imaging ◽

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Optical Tomography ◽

Assessment Process ◽

Current Direction ◽

Impedance Tomography ◽

Research Article ◽

Reconstruction Methods

Recently, the image reconstruction study on EIT plays a vital role in the medical application field for validation and calibration purpose. This research article analyzes the different types of reconstruction algorithms of EIT in medical imaging applications. Besides, it reviews many methods involved in constructing the electrical impedance tomography. The spatial distribution and resolution with different sensitivity has been discussed here. The electrode arrangement of various methods involved in the EIT system is discussed here. This research article comprises of adjacent drive method, cross method, and alternative opposite current direction method based on the voltage driven pattern. The assessment process of biomedical EIT has been discussed and investigated through the impedance imaging of the existent substances. The locality of the electrodes can be calculated and fixed for appropriate methods. More specifically, this research article discusses about the EIT image reconstruction methods and the significance of the alternative opposite current direction approach in the biomedical system. The change in conductivity test is further investigated based on the injection of current flow in the system. It has been established by the use of Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EDITORS) software, which is open-source software.

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‘Phantom Virtual’ Penampang Melintang Buah Manggis (Garcinia mangostana L.) Berbasis Konsep Rangkaian Resistor pada Tomografi Elektrik untuk Non Destructive Imaging Buah Tropik

10.31227/osf.io/hmpab ◽

2017 ◽

Author(s):

Agah D. Garnadi ◽

Amanatulhay Pribadi ◽

mn indro ◽

Mochamad Tito Julianto

Keyword(s):

Electrical Impedance Tomography ◽

Boundary Data ◽

Electrical Impedance ◽

Optical Tomography ◽

Diffuse Optical Tomography ◽

Garcinia Mangostana ◽

Impedance Tomography ◽

Data Set ◽

Non Destructive

Tomografi elektrik berguna untuk mencitrakan distribusi impedansi pada suatu benda. Tomografi dapat diaplikasikan ke berbagai bidang, salah satunya untuk bidang pasca panen maupun kwalitas penjaminan mutu sebagai peranti pencitraan bagian dalam buah secara utuh tanpa merusak. Buah manggis sebagai salah satu jenis buah tropis yang eksotis memiliki resistansi yang beragam bergantung pada material jaringan yang menyusunnya. Penampang buah manggis dimodelkan dalam bentuk phantom resistor model yang merepresentasikan tiga objek dengan resistansi berbeda, yaitu kulit luar, daging buah, dan biji. Dengan menggunakan boundary data simulator (BDS) berbasis rangkaian listrik dengan menggunakan pola arus tetanggan, dibangkitkan data set untuk phantom yang merepresentasikan jaringan melintang buah manggis. Data set yang dibangkitkan akan menjadi input inversi untuk memperoleh citra Non Destructive Imaging dengan menggunakan software rekonstruksi semisal EIDORS (electrical impedance tomography and diffuse optical tomography recosntrustion software), sebagai kalibrasi rekonstruksi.

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Extraction of cardiac and respiration signals in electrical impedance tomography based on independent component analysis

Journal of Electrical Bioimpedance ◽

10.5617/jeb.553 ◽

2019 ◽

Vol 4 (1) ◽

pp. 38-44 ◽

Cited By ~ 3

Author(s):

T. Rahman ◽

M.M Hasan ◽

A. Farooq ◽

M. Z. Uddin

Keyword(s):

Independent Component Analysis ◽

Electrical Impedance Tomography ◽

Spontaneous Breathing ◽

Electrical Impedance ◽

Random Noise ◽

Principal Component ◽

Component Analysis ◽

Independent Component ◽

Impedance Tomography ◽

Wide Range

Abstract Electrical Impedance Tomography (EIT) has successive wide range in impedance imaging, but still it is difficult to extract cardiac-related conductivity changes and respiratory-related conductivity changes in spontaneous breathing subjects. Quite a few methods are attempted to extract these two signals such as electrocardiogram gated averaging, frequency domain filtering and principal component analysis. However, such methods are not able to take apart these components properly or put some effort in real time imaging and have their own limitations. The purpose of this paper is to introduce a new method in the EIT clinical application field, Independent Component Analysis (ICA) to extract cardiac and respiratory related signals in electrical impedance tomography. Independent component analysis has been introduced to use in electrical impedance tomography but this is the first attempt ever to implement this method to separate these two signals and image those independent conductivity distribution of respiration and cardiac changes independently. Data has been collected from a spontaneous breathing subject. Filtration technique has been used to remove random noise and multi level spatial ICA has been applied to obtain independent component signals which has been later used in reconstruction algorithm for imaging.

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