scholarly journals Simultaneous Imaging of Bio- and Non-Conductive Targets by Combining Frequency and Time Difference Imaging Methods in Electrical Impedance Tomography

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 176
Author(s):  
Xue Bai ◽  
Dun Liu ◽  
Jinzhao Wei ◽  
Xu Bai ◽  
Shijie Sun ◽  
...  
Keyword(s):  
Image Fusion ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Imaging Modality ◽  
Time Difference ◽  
Frequency Difference ◽  
Electrical Measurements ◽  
Impedance Tomography ◽  
Imaging Methods ◽  
Difference Imaging

As a promising medical imaging modality, electrical impedance tomography (EIT) can image the electrical properties within a region of interest using electrical measurements applied at electrodes on the region boundary. This paper proposes to combine frequency and time difference imaging methods in EIT to simultaneously image bio- and non-conductive targets, where the image fusion is accomplished by applying a wavelet-based technique. To enable image fusion, both time and frequency difference imaging methods are investigated regarding the reconstruction of bio- or non-conductive inclusions in the target region at varied excitation frequencies, indicating that none of those two methods can tackle with the scenarios where both bio- and non-conductive inclusions exist. This dilemma can be resolved by fusing the time difference (td) and appropriate frequency difference (fd) EIT images since they are complementary to each other. Through simulation and in vitro experiment, it is demonstrated that the proposed fusion method can reasonably reconstruct both the bio- and non-conductive inclusions within the lung models established to simulate the ventilation process, which is expected to be beneficial for the diagnosis of lung-tissue related diseases by EIT.

AN EXPERIMENTAL ANALYSIS AND VALIDATION OF ELECTRICAL IMPEDANCE TOMOGRAPHY TECHNIQUE FOR MEDICAL OR INDUSTRIAL APPLICATION

2019 ◽  
Vol 31 (02) ◽  
pp. 1950010 ◽  
Author(s):  
Ramesh Kumar ◽  
Sharvan Kumar ◽  
A. Sengupta
Keyword(s):  
Current Pulse ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Imaging Modality ◽  
Current Source ◽  
Control Unit ◽  
Tikhonov Regularization Method ◽  
Impedance Tomography ◽  
Cross Sectional ◽  
On Chip

Electrical impedance tomography is a recently established technique by which impedance of an object (medical or nonmedical applications) is measured data from the surface of the object, and a numerically simulated reconstruction of the object internal shape of the image can be obtained. This imaging technique based on boundary or surface voltage is measured when the different current pattern is injected into it. For current pulse, we are creating a voltage controlled current source, which is based on the different RC circuits, according to current amplitude and frequency values. The current source used in inject the current pulse of the various phantoms. The current position and measuring voltage is controlled by the created control unit or programmable system on chip (PSOC) of the proposed EIT system. After that image reconstruction of the cross-sectional image of resistivity requires sufficient data collection from used phantoms, which is based on finite element method (FEM) method and Tikhonov regularization method with helps of graphical user interface (GUI) on MatLab. The objective of the GUI was to produce an image (2D/3D), impedance distribution graph, and the FEM mesh model according to used electrode combinations from the various phantoms. EIT system has a great potential for imaging modality, is non-invasive, radiation-free, and inexpensive for medical applications.

scholarly journals Frequency-difference electrical impedance tomography: Phantom imaging experiments

2010 ◽  
Vol 224 ◽  
pp. 012152 ◽  
Author(s):  
Sujin Ahn ◽  
Sung Chan Jun ◽  
Jin Keun Seo ◽  
Jeehyun Lee ◽  
Eung Je Woo ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Frequency Difference ◽  
Impedance Tomography ◽  
Phantom Imaging

An Experimental Measurement and Control of Human Body Stomach Using Electrical Impedance Tomography

2020 ◽  
pp. 2150103
Author(s):  
Ramesh Kumar ◽  
Rajesh Mahadeva
Keyword(s):  
Electrical Impedance Tomography ◽  
Human Body ◽  
Electrical Impedance ◽  
Imaging Modality ◽  
Current Source ◽  
Voltage Measurement ◽  
Impedance Tomography ◽  
Cross Sectional ◽  
Non Invasive ◽  
The Cross

A newly proven technique is non-invasive bio-impedance, and also known as Electrical Impedance Tomography (EIT), which is used for medical or non-medical applications. EIT images are based on the internal distributions of the conductivity or resistivity from the boundary data, which depend on the voltage measurement of the stomach attached electrodes of the human body. An experimental study of the EIT system presented here has been used 8/16 surface electrodes configurations for the human body’s stomach. Then, according to the data acquisition methods of the EIT, the surface potentials of the stomach through the current injection were measured. For current pulses, a voltage-controlled current source has been created, and the created current source is a combination of voltage to current converter and current signal generator. Current positions and measuring voltages have been calculated using the designed control unit. However, the imaging algorithm requires sufficient data through the experimental work, which defines the cross-sectional image of resistivity. The cross-sectional image has been based on the Finite Element Method (FEM). It produces 2D/3D images, impedance distribution graphs and Mesh models. The proposed EIT system has been used for non-medical and industrial applications, which have non-invasive, inexpensive, radiation-free and a high potential for imaging modality.

scholarly journals Spatially-Adaptive Variational Reconstructions for Linear Inverse Electrical Impedance Tomography

2020 ◽  
Vol 84 (3) ◽  
Author(s):  
M. Huska ◽  
D. Lazzaro ◽  
S. Morigi ◽  
A. Samorè ◽  
G. Scrivanti
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Mathematical Formulation ◽  
Variational Model ◽  
Electrical Measurements ◽  
Impedance Tomography ◽  
Engineering Technology ◽  
Spatially Adaptive ◽  
Spatially Variant ◽  
Spatially Varying

Abstract The inverse electrical impedance tomography (EIT) problem involves collecting electrical measurements on the smooth boundary of a region to determine the spatially varying electrical conductivity distribution within the bounded region. Effective applications of EIT technology emerged in different areas of engineering, technology, and applied sciences. However, the mathematical formulation of EIT is well known to suffer from a high degree of nonlinearity and severe ill-posedness. Therefore, regularization is required to produce reasonable electrical impedance images. Using difference imaging, we propose a spatially-variant variational method which couples sparsity regularization and smoothness regularization for improved EIT linear reconstructions. The EIT variational model can benefit from structural prior information in the form of an edge detection map coming either from an auxiliary image of the same object being reconstructed or automatically detected. We propose an efficient algorithm for minimizing the (non-convex) function based on the alternating direction method of multipliers. Experiments are presented which strongly indicate that using non-convex versus convex variational EIT models holds the potential for more accurate reconstructions.

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