Muhammad Saiful Badri Mansor

Advancements in Transmitters and Sensors for Biological Tissue Imaging in Magnetic Induction Tomography

Magnetic Induction Tomography (MIT), which is also known as Electromagnetic Tomography (EMT) or Mutual Inductance Tomography, is among the imaging modalities of interest to many researchers around the world. This noninvasive modality applies an electromagnetic field and is sensitive to all three passive electromagnetic properties of a material that are conductivity, permittivity and permeability. MIT is categorized under the passive imaging family with an electrodeless technique through the use of excitation coils to induce an electromagnetic field in the material, which is then measured at the receiving side by sensors. The aim of this review is to discuss the challenges of the MIT technique and summarize the recent advancements in the transmitters and sensors, with a focus on applications in biological tissue imaging. It is hoped that this review will provide some valuable information on the MIT for those who have interest in this modality. The need of this knowledge may speed up the process of adopted of MIT as a medical imaging technology.

Evaluation on the Sensitivity of Tri-Coil Sensor Jig for 3D Image Reconstruction in Magnetic Induction Tomography

The needs of accurate information from tomography images has led to the exploration of 3D imaging which attracts both medical field and industrial process as 3D imaging technique provides additional info compared to 2D. The same thing goes to Magnetic Induction Tomography (MIT) even 3D is still new to this modality. The challenge of 3D scheme to MIT is that the sensitivity at the boundary is more pronounce compared the centre of region of interest (ROI). The introduction of tri-coil sensor jig offers solution to this issue as three layers of sensors are located in this design, with excitation coils arranged at the middle layer. This arrangement strengthened the sensitivity at the centre of the z-axis between upper and lower layer through the existing of middle layer. This paper would like to discuss on the sensitivity of the z-axis of tri-coil sensor jig from the scope of metal imaging application. The simulation result has found that all the three coils are sensitive to the metal object at different z-positions. This result provides additional info as it will be integrated in the 3D image reconstruction algorithm process for providing accurate location of the 3D reconstructed images.

Evaluation of square type electromagnetic field screen implementation on interference effects in magnetic induction tomography modality

This paper discusses and evaluates the implementation of square type electromagnetic screen on the excitation coil of Magnetic induction tomography (MIT) through real experiment. By using electromagnetic screen, interference phenomena due to scattered primary field can be reduced, hence reducing the sources of errors in the measurement data. In this experiment, two types of screen with different thickness of 2 mm and 25 mm had been evaluated. The measurements have shown that relative to without screen, 2 mm thickness screen reduces the field at about 84.31% at the back area while increased the field strength up to 19.45% in the front region. Excitation screen with 25 mm thickness provides better reduction of 98.43% at the back, however there is also reduction at about 9.82% of the field strength at the front region. The result from this experiment provides valuable information on the specification needed when applying electromagnetic screen to the individual excitation coil in the MIT system.

Initial results on magnetic induction tomography hardware measurement using hall effect sensor application

Magnetic induction tomography (MIT) is among the new technology that compliment other tomography methods such as ultrasonic, optical, capacitance and several others. This type of tomography applies the magnetic field to detect the existence of the object that is going to image. Several methods are possible in constructing the magnetic induction hardware. Most of the researchers used coils for both transmitter and receiver which are more complicated and need large space. The Hall Effect sensors (HES) have the potential of replacing the coil at the receiver side since it has the ability to measure the value of magnetic field strength and convert it to voltage value. This concept is same as the ultrasonic sensors used in ultrasonic tomography instrumentation hardware. The results have shown that the pattern of capture data by hall effect sensor are almost the same pattern for all 8 sensors for each material used. This have given positive sign that HES is capable to be applied in MIT measurement system.