Magnetic induction tomography: comparison of the image quality using different types of receivers

High speed magneto-optical imaging system to investigate motion characteristics of arc plasma in enclosed chamber

Arc plasmas are common and important phenomena, which have been widely used in scientific research and industrial fields. It is a non-intrusive way to understand the dynamic characteristics of arc plasma by measuring magnetic field distribution and applying inverse method. Aiming to investigate the motion characteristics of arc plasma, a high-speed magneto-optical imaging system was developed, which mainly consists of a laser-driven light source, achromatic collimator, beam expander, polarized beam splitter, analyzer and high-speed camera. The calibration experiment of the system, which was conducted using a Faraday indicator with a Verdet constant of -96 rad/(T·m)@632.8 nm and Helmholtz coils, shows its magnetic sensitivity reaches 1 mT, spatial resolution is about 500μm, temporal resolution is 100μs as for a circular measuring area of 42 mm in diameter. The arcing experimental results also demonstrate that the developed system can obtain the 2D magnetic field distribution in real time with relatively high spatial and temporal resolution and reasonable magnetic sensitivity. It also provides an effective method to study the motion characteristics of arc plasma inside of an enclosed chamber.

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.