A New Method of Haemorrhagic Stroke Detection Via Deep Magnetic Induction Tomography

Abstract

Hemorrhage imaging is one of the most common applications of magnetic induction tomography (MIT). Depth and the mass of stroke stimulated (MSS) are the most important issues that need to be solved for this application. Transcranial magnetic stimulation (TMS) is a technique belonging to the deep brain stimulation (DBS) field, which aims at overcoming human diseases such as depression. TMS coils, namely, circular, figure-8, and H-coils, play an important role in TMS. Among these, H-coils individually focus on the issues of achieving effective stimulation of deep region. MIT and TMS mechanisms are similar. Herein, for the first time, improved TMS coils, including figure-8 and H-coils, are applied as MIT excitation coils to study the possibility of achieving the mass of stroke stimulated and deep detection through MIT. In addition, the configurations of the detection coils are varied to analyze their influence and determine the optimal coils array. Finally, MIT is used to detect haemorrhagic stroke occurring in humans, and the application of deep MIT to the haemorrhagic stroke problem is computationally explored. Results show that among the various coils, the improved H-coils have MSS and depth characteristics that enable the detection of deep strokes through MIT. Although the detecting depth of the figure-8 coil is weaker, its surface signal is good. The deep MIT technique can be applied to haemorrhagic detection, providing a critical base for deeper research.

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

“…In addition to the attenuation and blurring of the induction field over distance, there is another effect that further reduces the sensitivity at the center of the body: the induced eddy currents run in closed loops within the body, and the current density thus tends to be strongest near the surface, but decreases toward the center region (and along the axis of the coils), where it vanishes and no longer provides any information [8]. Therefore, only simulations of biomedical 3D MIT have been successful in resolving weakly conductive inhomogeneities at the center of a test body to this point [8,24,25]. Yet, MIT simulations can be too optimistic, as they can be based on idealized prerequisites that are difficult to implement in practice.…”

A novel sensor system to detect cerebral hemorrhage in rabbits through MIPS

“…Moreover, the induced secondary magnetic field is only ≤1% of the primary magnetic field. 6 To improve the detection sensitivity, back-off coils, 6 gradiometers, 7 and normal sensors 8 are utilized for the primary field compensation; symmetric cancelation-type sensors 9 are utilized to counteract the effect of common magnetic field caused by all factors except the object; transcranial magnetic stimulation and coils are used for magnetic induction tomography with deep detection, 10 ferrite core shield 11 is used to concentrate the primary magnetic field. However, these efforts focus mostly on the compensation or enhancement of the primary magnetic field 12 and do not consider its distribution.…”