An improved back-projection algorithm for magnetic induction tomography based on magnetic field lines

2014 ◽  
Author(s):  
Li Ke ◽  
Fengqiu Cao ◽  
Qiang Du
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Projection Algorithm ◽  
Back Projection ◽  
Field Lines ◽  
Magnetic Induction Tomography

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.

Simulative Study of Two-Phase Homogenous and Isotropic Media Imaging using Magnetic Induction Tomography

2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Zulkarnay Zakaria ◽  
Ibrahim Balkhis ◽  
Lee Pick Yern ◽  
Nor Muzakkir Nor Ayob ◽  
Mohd Hafiz Fazalul Rahiman ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Magnetic Induction ◽  
Optical Tomography ◽  
Reconstruction Algorithm ◽  
Projection Algorithm ◽  
Back Projection ◽  
Two Phase ◽  
Excitation Coil ◽  
Magnetic Induction Tomography ◽  
Linear Back Projection

Magnetic induction tomography is a new non-invasive technology, based on eddy current discovery of electromagnetic induction by Michael Faraday. Through this technique, the passive electrical properties distribution of an object can be obtained by the use of image reconstruction algorithm implemented in this system. There are many types of image reconstruction that have been developed for this modality, however in this paper only two algorithms discussed, Linear Back Projection and Eminent Pixel Reconstruction. Linear Back Projection algorithm is the most basic type of image reconstruction. It is the simplest and fast algorithm out of all types of algorithms, whereas Eminent Pixel Reconstruction algorithm is an improved algorithm which provided better images and has been implemented in other modalities such as optical tomography. This paper has implemented Eminent Pixel Reconstruction in magnetic induction tomography applications and the performance is compared to Linear Back Projection based on the simulation of the fourteen types of simulated phantoms of homogenous and isotropic conductivity property. It was found that Eminent Pixel Reconstruction has produced better images relative to Linear Back Projection, however the images are still poor when the objects are located near to the excitation coil or sensor and it is worse when the distance between objects are near to each other.

Simulation Analysis of the Sensitivity in Magnetic Induction Tomography Based on Perturbation Theory

2013 ◽  
Vol 749 ◽  
pp. 371-376
Author(s):  
Yang Xuan ◽  
Xu Wang ◽  
Cheng An Liu ◽  
Dan Yang
Keyword(s):  
Perturbation Theory ◽  
Salt Solution ◽  
Magnetic Induction ◽  
Imaging Modality ◽  
Reconstruction Algorithm ◽  
Target Object ◽  
Back Projection ◽  
Filtered Back Projection ◽  
Projection Reconstruction ◽  
Magnetic Induction Tomography

Magnetic induction tomography (MIT) is a noninvasive and contactless imaging modality which aims at the reconstruction of the electrical conductivity in objects from alternating magnetic fields. Filtered back projection reconstruction algorithm is widely used in biomedical imaging field, and tried to use in MIT. Finite element analysis model has been established based on Scharfetter coil-coil model and perturbation theory, then simulated coaxial coil system by ANSYS software, the perturbation aroused by a target object moving on vertical coil axis. The sensitivity of a target object moves in vacuum and a salt solution were calculated respectively, the characteristics of the perturbation sensitivity in a salt solution were analyzed. The conditions of filtered back projection reconstruction algorithm in MIT were discussed.

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.

Effective Sputtering System for Deposition of Wear-Resistant and Anticorrosion Coatings

2015 ◽  
Vol 834 ◽  
pp. 61-70
Author(s):  
Aleksander Sergeevich Metel ◽  
Sergey Nikolaevich Grigoriev ◽  
Vasilii Petrovich Bolbukov ◽  
Yury Andreevich Melnik
Keyword(s):  
Magnetic Field ◽  
Glow Discharge ◽  
Hollow Cathode ◽  
Magnetic Induction ◽  
Anticorrosion Coatings ◽  
Field Lines ◽  
The Magnetic Field ◽  
Target Center ◽  
Cylindrical Hollow Cathode ◽  
Sputtering System

Results of a target sputtering investigation have been obtained, the target being positioned on the bottom of a cylindrical hollow cathode covered by a grid. It was shown that influence on the glow discharge of a nonuniform magnetic field with lines crossing the target center as well as the grid, the hollow cathode and the target periphery, where the field lines are arc-shaped, depends on the magnetic induction on the target edge. Due to ionization by electrons emitted by the cathode and forced by the magnetic field to approach to the target more frequently the plasma density near the target grows up and more than a half of all ions produced in the discharge quite uniformly sputter the target

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.

scholarly journals Magnetic Induction Tomography: Receiver Circuit and Its Design Criteria

2013 ◽  
Vol 64 (5) ◽  
Author(s):  
Zulkarnay Zakaria ◽  
Muhammad Saiful Badri Mansor ◽  
Ruzairi Abdul Rahim ◽  
Ibrahim Balkhis ◽  
Mohd Hafiz Fazalul Rahiman ◽  
...  
Keyword(s):  
Magnetic Induction ◽  
Imaging System ◽  
Frame Rate ◽  
Projection Algorithm ◽  
Industrial Processes ◽  
System Component ◽  
High Quality ◽  
Tomography System ◽  
Component Selection ◽  
Magnetic Induction Tomography

This paper discusses the receiver circuit and criteria for component selection towards the application of a real-time magnetic induction tomography system. Component selection plays an important role since image reconstruction of the object of interest with high quality and at a higher frame rate cannot be achieved without the right parameter criteria. The demands for a high quality imaging system have recently been increasing, especially in industrial processes involving dynamic movement, thus this paper may provide valuable information on better magnetic induction tomography system implementation for industrial processes and biomedical imaging through the use of a coil as a transmitter and also a receiver. The linear back projection algorithm has been employed in this system and has proven capable of identifying the location and size of the object based on the reconstructed images.

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