Simulation and Analysis of Variable Antenna Designs for Effective Stroke Detection

Amor Smida

doi:10.14569/ijacsa.2020.0111230

Abstract

The variety of applications of patch antenna for portable applications has opened the avenues for the possibilities of having compact, cost-efficient, and life-saving devices. Considering the challenges of portability and cost in making it feasible for detecting strokes in the masses of developing countries where the demand is quite high, this study builds the groundwork for such device fabrication. In total five antenna designs were investigated for their assessment in identifying the stroke. Two main studies of electromagnetic wave interaction and bio-heating of the human head phantom had been accomplished and the results are compared. The main comparison and identification of the stroke location with the human head phantom are presented by the specific absorption rate (SAR), both visualized as volumetric plot and stacked contour slices for clarifying the shape and positioning of the stroke in vertical and horizontal dimensions. The results show that the SAR values for Antenna A & D are the lowest with the values of 1.44 x 10-5 W/kg and 1.96 x 10-5 W/kg, respectively. But the induced electric field and isothermal temperature achieved were highest by Antenna D, with values of 0.25 emw and 133.92 x 10-8 K, respectively; and, the 2-D far-field radiation patterns confirmed better performance by it amongst all others. Hence, making the Antenna D as the most preferred choice for the prototyping stage. The overall trade-off of key parameters is studied herein in this simulation study and based on that the most suitable antenna design is proposed for the experimental prototype testing. The results suggest that the simulation results give a clear insight into the feasibility of stroke detection with the proposed setup and presents high viability for portable, low-cost, and rapid stroke detection applications.

Highlights

In the past decade, the WHO declared cerebrovascular accidents as the first reason for neurological dysfunction in the western world and based on worldwide statistics second most critical reason for mortality and the third rising reason for disability [1]
The mean relative permittivity contour graphs for all antenna designs are shown in Fig. 2 and were recreated using imported magnetic resonance imaging (MRI) image data [31] from which permittivity values are determined
Based on the solutions derived from this analysis the temperature distribution plots are generated as shown by Fig. 3 and Fig. 4

Summary

INTRODUCTION

The WHO declared cerebrovascular accidents (stroke) as the first reason for neurological dysfunction in the western world and based on worldwide statistics second most critical reason for mortality and the third rising reason for disability [1]. Of which the Microwave Imaging (MWI) seems very promising due to its ease of setup and operation; with the capability to give a quick diagnosis as a complementary tool for the prehospital record on the type, size, shape, in some cases the number of blood blockages and as a harmless setup for continuous monitoring of the effect due to ongoing treatment since no harmful irradiations are involved [11,12,13,14]. MWI takes the concept of variable reflections from surfaces with different permittivity and conductivity and helps build a 3D mapping of the model under study This concept is explicitly applied for mapping the human head phantom with the idea to locate the stroke at early stages with clear visualization of its shape, size, and most importantly their numbers with each one’s. The antenna designs are simulated to observe the effect on the reflection parameter/gain and the changes of SAR value with different designs

Simulation Setup

Antenna Designs

RESULTS AND DISCUSSIONS

CONCLUSIONS