A Portable Electromagnetic Head Imaging System Using Metamaterial Loaded Compact Directional 3D Antenna

Mohammad Shahidul Islam,Mohammad Tariqul Islam,Ahasanul Hoque,Nowshad Amin,Md Tarikul Islam,Muhammad E H Chowdhury

doi:10.1109/access.2021.3069712

Abstract

A non-invasive, low-powered, and portable electromagnetic (EM) head imaging system is presented using metamaterial (MTM) loaded compact directional 3D antenna. The antenna consists of two slotted dipole elements with $2\times 3$ and $3\times 3$ finite MTM array elements in top and ground, respectively, and folded parasitic elements that operate within the frequency range of 1.12 GHz to 2.5 GHz. The MTM array elements are optimized to enhance the overall performance regarding antenna bandwidth, realized gain, efficiency, and directionality in both free space and proximity to the head model. The mathematical modelling is also analyzed to justify the integration of MTM unit cells to the top and ground side of the antenna. The impact of MTM on SAR analysis is also performed. A tissue-mimicking 3D head phantom is fabricated and measured to validate the antenna performance. A nine-antenna portable setup is used with the fabricated phantom to measure and collect the scattering parameters that are later analyzed to detect and reconstruct the haemorrhage images by applying the updated IC-CF-DMAS algorithm. The overall performance demonstrates the feasibility of the proposed system as a portable platform to successfully detect, locate and monitor the haemorrhages inside the head in EM imaging system.

Highlights

Brain injury is a major cause of mortality and disability worldwide, categorized into traumatic and non-traumatic injuries
The most common brain injury is intracranial haemorrhage (ICH), which refers to blood accumulation inside the human head
This paper presents a portable EM head imaging system with the MTM loaded compact directional 3D antenna

Summary

INTRODUCTION

Brain injury is a major cause of mortality and disability worldwide, categorized into traumatic and non-traumatic injuries. There is no analysis regarding radiation efficiency, realized gain, and SAR performance when placed near the head model. This paper presents a portable EM head imaging system with the MTM loaded compact directional 3D antenna. The finite MTM array elements optimize the antenna performance by increasing the bandwidth, realized gain, and efficiency. The MTM structures enhance radiation efficiency and gain and decrease SAR value when placed near the head model. The MTM loaded antenna increases the radiation efficiency, realized gain, and directionality when placed near the head model. For the mathematical modeling of MTM array elements, a simplified equivalent circuit based on lumped element transmission line principle [39] is presented in Figure 5(b) for the proposed MTM loaded 3D antenna. Reference X-axis is taken with differential length (dx) and voltage relation between terminal 1 to terminal 2 as follows-

Cs i1dt

DISCUSSION

CONCLUSION