Small Scale Non-Invasive Imaging Using Magnetic Induction Tomography - Hardware Design

This study is conducted to preliminary image the conductivity profile through the development of small scale non-invasive Magnetic Induction Tomography (MIT) system.  It is proved that the Magnetic Induction Tomography interested in mapping the passive electrical properties of materials; conductivity (σ), permittivity (ε) and permeability (µ) in both process and medical tomography.  The system is realized by designing the functional ferrite-core coil sensors, electronic measurements circuits for excitation and receiving coil, data acquisition system for transferring the data to the PC and suitable image reconstruction algorithm for providing the conductivity distributions measurement. The important characteristic for excitation coil is the one that can maintain the stability the optimum sine wave frequency ranging from 400 kHz up to 10 MHz.  The sine waves are fed to the excitation coil through the application of high current amplifier component respectively. In the experiments, the copper phantom represent as high conductivity material were placed into the region of interest.  The initial 16 channel MIT consists of 8 excitation coil and 8 receiving coil stacked alternately.  On the receiving circuit, the major problem is the weak secondary signal perturbation sensed by the receiving coil has been improved by placing the variable amplifier on each receiver. The enhancement of conductivity profile imaging has been made by using a common Linear Back Projection (LBP) algorithm.  The measurement was done on single and dual arrangement of copper phantom aligns in random coordinate so that the sensitivity of the excitation and receiving coil sensor can be experimentally observed.  The imaging’s results show that the hardware’s and algorithm used was capable to process the data captured at the receiver.  The results obtained can be useful for further improvement and research towards magnetic induction tomography

A review of non-invasive imaging: the opportunity of magnetic induction tomography modality in agarwood industry

The needs for non-invasive technique in agarwood industry could enhance and preserve the future of this industry in Malaysia as well as in most of the Asia countries. Normally karas tree which produces agarwood needs at least more than ten years to yield a matured agarwood resin. Thus cutting down the immature trees without pre-assessment on the agarwood content would become a waste of resources. This paper discusses the NDE techniques in wood industry which has the potential to be applied in karas tree for pre-assessment of agarwood volume embedded inside the trees. Finally future research in agarwood imaging using Magnetic Induction Tomography modality is addressed

Magnetic induction tomography: a brief review

Magnetic Induction Tomography (MIT) is a contactless non-invasive imaging technique that interested in mapping the passive electrical properties of a material; conductivity, permittivity and permeability. This paper presents the criteria and previous functional specification involving the development of MIT, focusing in conductivity imaging. Various ways have been implemented from a simple electronic configuration of the front-end sensory circuit, data acquisition system, reconstruction algorithm and graphical user interfacing (GUI) tools. Induction sensors are paramount as it does provide the signal source for time varying magnetic field to the coils. The advantages and limitations of MIT are also presented. Many more advancement can be expected to enhance the lack of MIT especially in spatial resolution and dynamic response of the sensor

Simulation study on non-homogenous system of non-invasive ERT using comsol multiphysics

The non-invasive sensing technique is one of the favourite sensing techniques applied in the process tomography because it has not a direct contact with the medium of interest. The objective of this paper is to analyse the simulation of the non-homogenous system of the non-invasive ERT using finite element software; COMSOL Multiphysics. In this simulation, the liquid-air medium is chosen as the non-homogenous system. A different analysis of the non-homogenous system in term of the different position of the single air, different size of the single air and the multiple air inside the vessel were investigated in this paper. As a result, the location, size and multiple air inside the pipe will influence the output of the non-invasive ERT system. A liquid-gas medium of nonhomogenous ERT system will have a good response if the air is located near the source, the size of the air is large enough and it has multiple air locations inside the pipe

Initial study on optical tomographic instrumentation system based on CMOS area image sensors

This research investigates the use of complementary metal-oxide semiconductor (abbreviated as CMOS) area image sensors in optical tomography system. The system consists of a lighting system, a measurement section and a data acquisition system. Two area image sensors are configured around a square shaped measurement section for a two projections system. Each area image sensors consists of 1600 ´ 1400 pixels with a pixel size of 2.8 ´ 2.8 micron, hence producing a high resolution system. This paper explains the initial study on activating the CMOS area image sensor model MT9D1C12STC manufactured by Micron Technology

Magnetic induction tomography (MIT)

The method is used in nondestructive testing and geophysics, and has potential applications in medicine. It is also used to generate 3D images of passive electromagnetic properties, which has applications in brain imaging, cryosurgery monitoring in medical imaging, and metal flow visualization in metalworking processes