A new excitation field for magnetic induction tomography based on the focusing magnetic field

2014 ◽  
Author(s):  
Lv Yi ◽  
Wang Xu ◽  
Jin Jingjing ◽  
Liu Jianhui ◽  
Han Changjun ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Excitation Field ◽  
Magnetic Induction Tomography

scholarly journals A Simulation Magnetic Induction Tomography (MIT) for Agarwood using COMSOL Multiphysics

2021 ◽  
Vol 10 (3) ◽  
pp. 67-71
Author(s):  
Nurfarahin Ishak ◽  
Chua King Lee ◽  
Siti Zarina Mohd Muji
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Electromagnetic Properties ◽  
Induced Current ◽  
Solenoid Coil ◽  
Agriculture Industry ◽  
Eddy Current Effect ◽  
Coil Diameter ◽  
Great Performance ◽  
Magnetic Induction Tomography

Magnetic induction tomography is an imaging technique used to image electromagnetic properties of an object by using the eddy current effect. (MIT) is a non-destructive method that greatly is used in the agriculture industry. This method provided an opportunity to improve the quality of agricultural products. MIT simulation was used for agarwood existence detection. This paper presented for the simulation system contains 7 channel coils receiver and a channel transmitter which is a sensing detector. This experiment aims to demonstrate the reaction of induced current density and magnetic field at 10 MHz frequency. Then, it also determines the optimal solenoid coil to be used for a better outcome for the magnetic induction system. The simulation result shows that coil diameter, coil length, and coil layer have a crucial role in the great performance of the induced current and magnetic field. The more coil turns, the greater the strength of the permanent magnetic field around the solenoid coil. The result of the simulation is important and needs to be considered to verify the effectiveness of the system for developing the magnetic induction circuit design.

scholarly journals Three-Dimensional Magnetic Induction Tomography: Practical Implementation for Imaging throughout the Depth of a Low Conductive and Voluminous Body

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7725
Author(s):  
Martin Klein ◽  
Daniel Erni ◽  
Dirk Rueter
Keyword(s):  
Magnetic Induction ◽  
3D Imaging ◽  
Three Dimensional ◽  
Practical Implementation ◽  
Excitation Field ◽  
Technical Performance ◽  
Central Regions ◽  
Entire Depth ◽  
Magnetic Induction Tomography ◽  
Practical Demonstration

Magnetic induction tomography (MIT) is a contactless, low-energy method used to visualize the conductivity distribution inside a body under examination. A particularly demanding task is the three-dimensional (3D) imaging of voluminous bodies in the biomedical impedance regime. While successful MIT simulations have been reported for this regime, practical demonstration over the entire depth of weakly conductive bodies is technically difficult and has not yet been reported, particularly in terms of more realistic requirements. Poor sensitivity in the central regions critically affects the measurements. However, a recently simulated MIT scanner with a sinusoidal excitation field topology promises improved sensitivity (>20 dB) from the interior. On this basis, a large and fast 3D MIT scanner was practically realized in this study. Close agreement between theoretical forward calculations and experimental measurements underline the technical performance of the sensor system, and the previously only simulated progress is hereby confirmed. This allows 3D reconstructions from practical measurements to be presented over the entire depth of a voluminous body phantom with tissue-like conductivity and dimensions similar to a human torso. This feasibility demonstration takes MIT a step further toward the quick 3D mapping of a low conductive and voluminous object, for example, for rapid, harmless and contactless thorax or lung diagnostics.

scholarly journals NUMERICAL ASPECTS OF THE SECONDARY MAGNETIC FIELD MAPPING IN MAGNETIC INDUCTION TOMOGRAPHY

2017 ◽  
Vol 7 (3) ◽  
pp. 11-14
Author(s):  
Beata Szuflitowska ◽  
Marcin Ziolkowski ◽  
Krzysztof Stawicki
Keyword(s):  
Magnetic Field ◽  
Cell Volume ◽  
Eddy Current ◽  
Magnetic Induction ◽  
Imaging Techniques ◽  
Magnetic Field Mapping ◽  
Electrical Conductivities ◽  
Eddy Current Density ◽  
Magnetic Induction Tomography

Magnetic Induction Tomography (MIT) belongs to the noncontact electromagnetic imaging techniques. This paper focuses on determination of a secondary magnetic field map calculated with the help of the Biot-Savart law around the low-conductivity object. The inclusions of various shapes and different electrical conductivities values and two measurement planes are considered. In each case the objects’ single maximal cell volume with assumed uniform eddy current density has been determined. In order to keep the relative error below 1% the object should be divided in most cases into elements with maximal cell volume equal to 0.244 mm3 for yz − plane, and 0.03 mm3 for xy − plane.

An Improved Back-Projection Algorithm for Magnetic Induction Tomography Image Reconstruction

2013 ◽  
Vol 647 ◽  
pp. 630-635 ◽  
Author(s):  
Li Ke ◽  
Xiao Lin ◽  
Qiang Du
Keyword(s):  
Magnetic Field ◽  
Image Reconstruction ◽  
Magnetic Induction ◽  
Projection Algorithm ◽  
Projection Area ◽  
Homogeneous Field ◽  
Back Projection ◽  
Field Lines ◽  
Magnetic Induction Tomography ◽  
The Magnetic Field

Magnetic induction tomography (MIT) acted as a contactless and non-invasive medical imaging technology has aroused wide concern, while a large amount of calculation and a series of convergence problems in the solution of the inverse problem become technical difficulties for MIT. In order to solve these problems, an improved back-projection image reconstruction algorithm based on the magnetic field lines distribution is presented in this paper. Firstly, the eddy current problem of MIT was solved by the finite element method to obtain the magnetic field distribution. Secondly, the back-projection areas were divided according to the magnetic field lines distribution in the homogeneous field. Finally, image reconstruction was realized by projecting the phase shifts back along the corresponding projection area. The reconstruction results for perturbations with different conductivities appearing at different locations reveal that the improved back-projection algorithm for MIT owning the character of high speed performs well in reflecting location and shape information of the perturbation.

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

Inspection of defects in CFRP by improved magnetic induction tomography

2019 ◽  
Vol 61 (3) ◽  
pp. 255-259
Author(s):  
Lipan Zhang ◽  
Qifeng Meng ◽  
Kai Song ◽  
Ming Gao ◽  
Zhiyuan Cheng
Keyword(s):  
Magnetic Induction ◽  
Magnetic Induction Tomography

Image Reconstruction with the Fourier Coefficients for Magnetic Induction Tomography

2020 ◽  
Vol 16 (2) ◽  
pp. 156-163
Author(s):  
Jingwen Wang ◽  
Xu Wang ◽  
Dan Yang ◽  
Kaiyang Wang
Keyword(s):  
Inverse Problem ◽  
Image Reconstruction ◽  
Magnetic Induction ◽  
Fourier Coefficients ◽  
Signal Reconstruction ◽  
Reconstruction Algorithm ◽  
Reconstruction Method ◽  
Measurement Equation ◽  
Image Reconstruction Method ◽  
Magnetic Induction Tomography

Background: Image reconstruction of magnetic induction tomography (MIT) is a typical ill-posed inverse problem, which means that the measurements are always far from enough. Thus, MIT image reconstruction results using conventional algorithms such as linear back projection and Landweber often suffer from limitations such as low resolution and blurred edges. Methods: In this paper, based on the recent finite rate of innovation (FRI) framework, a novel image reconstruction method with MIT system is presented. Results: This is achieved through modeling and sampling the MIT signals in FRI framework, resulting in a few new measurements, namely, fourier coefficients. Because each new measurement contains all the pixel position and conductivity information of the dense phase medium, the illposed inverse problem can be improved, by rebuilding the MIT measurement equation with the measurement voltage and the new measurements. Finally, a sparsity-based signal reconstruction algorithm is presented to reconstruct the original MIT image signal, by solving this new measurement equation. Conclusion: Experiments show that the proposed method has better indicators such as image error and correlation coefficient. Therefore, it is a kind of MIT image reconstruction method with high accuracy.

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