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Amin Abbosh - One of the best experts on this subject based on the ideXlab platform.
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Wearable Electromagnetic Head Imaging Using Magnetic-based Antenna Arrays
2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, 2019Co-Authors: Abdulrahman Shueai Mohsen Alqadami, Konstanty S. Bialkowski, Anthony E. Stancombe, Nghia Nguyen-trong, Amin AbboshAbstract:A wearable electromagnetic Head Imaging system for brain bleeding detection using a flexible magnetic-based antenna array is presented. The antenna arrays in a wearable strap-like structure are designed on a polymer magnetic composite substrate with a dielectric permittivity of 5.5, and magnetic permeability of 4. The antenna consists of a conventional rectangular patch with row of shorting pins. The combination of the remarkable magnetic properties material and the shorting pins results in a compact, unidirectional and wideband (0.72 GHz- 1.58 GHz) antenna that satisfies the requirement of the electromagnetic Imaging system. A 24-array of antenna is embedded inside the substrate in the form of a wearable strap that can fit an average human Head. The antenna arrays are preliminarily evaluated on an average Head model using CST software. The simulation-based constructed images of bleeding emulating target using a confocal image algorithm indicate the possibility of using such approach as a wearable system to detect bleeding inside the brain.
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Portable Microwave Head Imaging System Using Software-Defined Radio and Switching Network
IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology, 2019Co-Authors: Anthony E. Stancombe, Konstanty S. Bialkowski, Amin AbboshAbstract:Head Imaging plays an imperative role in the detection and localization of conditions affecting the brain, such as strokes, cancerous tumors, and hemorrhages caused by trauma. Current systems require the patient to be transported to the Imaging device that increases the time taken to apply treatments, allowing the patient's condition to worsen. This paper proposes a portable microwave Head Imaging system that can easily be taken to the patient. The system utilizes a novel combination of a software-defined radio and solid-state switching network to collect the Imaging data and operates in the frequency band of 0.85–2 GHz. It can capture input signals over a range of approximately 106 dB, which is suitable for detecting realistic brain injuries. The concept has been validated through experimental data collection and confocal image generation and was capable of producing images in less than 1 min. A simplified Head phantom was developed for gathering the verification data and proved that the system was capable of locating targets with dielectric properties similar to brain tumors and bleeds. The presented design is highly accessible and achieved through being small, light, and inexpensive, which are key factors that could help save lives in time-critical medical emergencies.
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Fabrication and Characterization of Flexible Polymer Iron Oxide Composite Substrate for the Imaging Antennas of Wearable Head Imaging Systems
IEEE Antennas and Wireless Propagation Letters, 2018Co-Authors: Abdulrahman Shueai Mohsen Alqadami, B. J. Mohammed, Konstanty S. Bialkowski, Amin AbboshAbstract:Given the increased interest in wearable electromagnetic Imaging systems, developing a low-cost, lightweight, flexible, and conformal customized substrate to accommodate the Imaging antenna array is essential. The characterization and assessment of a custom-made composite substrate using a flexible polymer poly-di-methyl-siloxane (PDMS) and magnetite iron oxide ( ${\text{FeO.Fe}}_{2}{\text{O}}_{3}$ ) for wearable Head Imaging systems is presented. Micro-scale ${\text{FeO.Fe}}_{2}{\text{O}}_{3}$ particles are homogeneously combined with PDMS in different ratios to build the flexible engineered magneto-dielectric (MD) composite substrate. Besides the low cost, fabrication simplicity, and durability, the magnetite ${\text{FeO.Fe}}_{2}{\text{O}}_{3}$ particles can be used to control the relative permittivity and permeability over a wide range of values to suit the proposed application. The permittivity, permeability, and losses of the developed substrate are extracted using a custom-made two-port multilayer microstrip transmission line test fixture with the help of conformal mapping algorithms. The characterization is performed across the microwave frequency range 1.2–4 GHz, which is widely adopted for Head Imaging. The extracted permittivity is successfully verified by using a Keysight 85070E dielectric slim probe kit.
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Fabrication and Characterization of Flexible Polymer Iron Oxide Composite Substrate for the Imaging Antennas of Wearable Head Imaging Systems
IEEE Antennas and Wireless Propagation Letters, 2018Co-Authors: Abdulrahman Shueai Mohsen Alqadami, B. J. Mohammed, Konstanty S. Bialkowski, Amin AbboshAbstract:Given the increased interest in wearable electromagnetic Imaging systems, developing a low-cost, lightweight, flexible, and conformal customized substrate to accommodate the Imaging antenna array is essential. The characterization and assessment of a custom-made composite substrate using a flexible polymer poly-di-methyl-siloxane (PDMS) and magnetite iron oxide ( ${\text{FeO.Fe}}_{2}{\text{O}}_{3}$ ) for wearable Head Imaging systems is presented. Micro-scale ${\text{FeO.Fe}}_{2}{\text{O}}_{3}$ particles are homogeneously combined with PDMS in different ratios to build the flexible engineered magneto-dielectric (MD) composite substrate. Besides the low cost, fabrication simplicity, and durability, the magnetite ${\text{FeO.Fe}}_{2}{\text{O}}_{3}$ particles can be used to control the relative permittivity and permeability over a wide range of values to suit the proposed application. The permittivity, permeability, and losses of the developed substrate are extracted using a custom-made two-port multilayer microstrip transmission line test fixture with the help of conformal mapping algorithms. The characterization is performed across the microwave frequency range 1.2–4 GHz, which is widely adopted for Head Imaging. The extracted permittivity is successfully verified by using a Keysight 85070E dielectric slim probe kit.
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Flexible Antenna on High Permeability Substrate for Electromagnetic Head Imaging Systems
2018 IEEE International Symposium on Antennas and Propagation & USNC URSI National Radio Science Meeting, 2018Co-Authors: Abdulrahman Shueai Mohsen Alqadami, Konstanty S. Bialkowski, Amin AbboshAbstract:The performance assessment and analysis of a wearable microstrip antenna based on high permeability material substrate in Head Imaging system is presented. The antenna is designed on polymer RTV6166-iron oxide substrate with relative permittivity and relative permeability of 3 and 5, respectively. The antenna consists of an inset-fed microstrip rectangular patch with dimensions of 44×72 mm, connected to 50 Ω feed. To evaluate the effect of the permeability in electromagnetic Head imagining, the antenna is benchmarked against another similarly geometrized polymer RTV6166 based with unity permeability. Numerical simulations using CST Microwave Studio for both antennas are performed in free space and on a 3D human Head model. The simulations results show that the antenna with high permeability exhibits better reflection coefficient (S 11 ) and electromagnetic penetration inside the human Head tissues which will result in improved detection and image resolution.
Ahmed Toaha Mobashsher - One of the best experts on this subject based on the ideXlab platform.
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wearable electromagnetic Head Imaging system using flexible wideband antenna array based on polymer technology for brain stroke diagnosis
IEEE Transactions on Biomedical Circuits and Systems, 2019Co-Authors: Abdulrahman S M Alqadami, Konstanty S. Bialkowski, Ahmed Toaha Mobashsher, A M AbboshAbstract:Given the increased interest in a fast, portable, and on-spot medical diagnostic tool that enables early diagnosis for patients with brain stroke, a new approach of a wearable electromagnetic Head Imaging system based on the polymer material is proposed. A flexible low-profile, wideband, and unidirectional antenna array with electromagnetic band gap (EBG) and metamaterial (MTM) unit cells reflector is utilized. The designed antenna consists of a 4 × 4 radiating patch loaded with symmetrical extended open-ended U-slots and fed by combination of series and corporate transmission lines. A mushroom-like 10-EBG unit cell arrays are arranged around the feeding network to reduce surface waves, whereas 4 × 4 MTM unit cells are placed on the back-side of the antenna to enable unidirectional radiation. The antenna is designed and embedded on a multilayer low cost, low loss, transparent, and robust polymer poly-di-methyl-siloxane (PDMS) substrate and optimized to operate in contact with the human Head. The simulated and measured results show that the antenna has a fractional bandwidth of 53.8% (1.16–1.94 GHz), more than 80% of radiation efficiency, and satisfactory field penetration in the Head tissues with a safe specific absorption rate. An eight-element array is then configured on 300 × 360 × 4.1 mm3 PDMS material covering an average human Head size and used as a worn part of the Imaging system. A realistic-shaped 3-D specific anthropomorphic mannequin (SAM) Head phantom is used to verify the performance of the designed array. The Imaging results indicate the possibility of using the designed conformal array to detect a bleeding inside the brain using a confocal image algorithm.
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Design and Experimental Evaluation of a Non-Invasive Microwave Head Imaging System for Intracranial Haemorrhage Detection.
PloS one, 2016Co-Authors: Ahmed Toaha Mobashsher, Amin Abbosh, Konstanty S. Bialkowski, Stuart CrozierAbstract:An intracranial haemorrhage is a life threatening medical emergency, yet only a fraction of the patients receive treatment in time, primarily due to the transport delay in accessing diagnostic equipment in hospitals such as Magnetic Resonance Imaging or Computed Tomography. A mono-static microwave Head Imaging system that can be carried in an ambulance for the detection and localization of intracranial haemorrhage is presented. The system employs a single ultra-wideband antenna as sensing element to transmit signals in low microwave frequencies towards the Head and capture backscattered signals. The compact and low-profile antenna provides stable directional radiation patterns over the operating bandwidth in both near and far-fields. Numerical analysis of the Head Imaging system with a realistic Head model in various situations is performed to realize the scattering mechanism of haemorrhage. A modified delay-and-summation back-projection algorithm, which includes effects of surface waves and a distance-dependent effective permittivity model, is proposed for signal and image post-processing. The efficacy of the automated Head Imaging system is evaluated using a 3D-printed human Head phantom with frequency dispersive dielectric properties including emulated haemorrhages with different sizes located at different depths. Scattered signals are acquired with a compact transceiver in a mono-static circular scanning profile. The reconstructed images demonstrate that the system is capable of detecting haemorrhages as small as 1 cm3. While quantitative analyses reveal that the quality of images gradually degrades with the increase of the haemorrhage’s depth due to the reduction of signal penetration inside the Head; rigorous statistical analysis suggests that substantial improvement in image quality can be obtained by increasing the data samples collected around the Head. The proposed Head Imaging prototype along with the processing algorithm demonstrates its feasibility for potential use in ambulances as an effective and low cost diagnostic tool to assure timely triaging of intracranial hemorrhage patients.
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portable wideband microwave Imaging system for intracranial hemorrhage detection using improved back projection algorithm with model of effective Head permittivity
Scientific Reports, 2016Co-Authors: Ahmed Toaha Mobashsher, Ahmed Mahmoud, A M AbboshAbstract:Intracranial hemorrhage is a medical emergency that requires rapid detection and medication to restrict any brain damage to minimal. Here, an effective wideband microwave Head Imaging system for on-the-spot detection of intracranial hemorrhage is presented. The operation of the system relies on the dielectric contrast between healthy brain tissues and a hemorrhage that causes a strong microwave scattering. The system uses a compact sensing antenna, which has an ultra-wideband operation with directional radiation, and a portable, compact microwave transceiver for signal transmission and data acquisition. The collected data is processed to create a clear image of the brain using an improved back projection algorithm, which is based on a novel effective Head permittivity model. The system is verified in realistic simulation and experimental environments using anatomically and electrically realistic human Head phantoms. Quantitative and qualitative comparisons between the images from the proposed and existing algorithms demonstrate significant improvements in detection and localization accuracy. The radiation and thermal safety of the system are examined and verified. Initial human tests are conducted on healthy subjects with different Head sizes. The reconstructed images are statistically analyzed and absence of false positive results indicate the efficacy of the proposed system in future preclinical trials.
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performance of directional and omnidirectional antennas in wideband Head Imaging
IEEE Antennas and Wireless Propagation Letters, 2016Co-Authors: Ahmed Toaha Mobashsher, Amin AbboshAbstract:Researchers have proposed numerous wideband antennas with directional or omnidirectional radiations to meet the requirements of microwave-based Head Imaging systems. This letter aims to study the effect of directionality on image quality of those systems. Hence, both directional and omnidirectional wideband antennas are designed and prototyped. Both antennas cover a wide bandwidth (1.25–2.4 GHz) that is typically used in microwave Head Imaging and attain a boresight average gain of 3.5 dBi. The antennas’ near-field radiation patterns are measured and analyzed. The antennas’ transient pulse performance in the near-field region along boresight direction is also studied. It is observed that without the effects of multipath inside the Head, the directional antenna provides 20% higher impulse fidelity and 4 dB more peak transient response than the omnidirectional antenna. An experimental verification is examined by Imaging a realistic artificial Head phantom with an emulated brain injury. Quantitative analysis of the reconstructed images demonstrates that directional antenna yields more focused images with low artifacts than omnidirectional antenna.
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Performance comparison of directional and omnidirectional ultra-wideband antennas in near-field microwave Head Imaging systems
2016 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2016Co-Authors: Ahmed Toaha Mobashsher, Amin AbboshAbstract:The objective of this paper is to study the effect and suitability of directionality in near-field microwave Head Imaging system. To that end, the near-field performances of directional and omnidirectional antennas are compared. The Imaging performance comparison is carried out through experimental validation of a realistic artificial Head phantom with an emulated brain injury. The results conclude that the directional antenna yields more focused images with low artifacts than the omnidirectional antenna.
Amin Abbosh - One of the best experts on this subject based on the ideXlab platform.
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Compact Unidirectional Conformal Antenna Based on Flexible High-Permittivity Custom-Made Substrate for Wearable Wideband Electromagnetic Head Imaging System
IEEE Transactions on Antennas and Propagation, 2020Co-Authors: Abdulrahman Shueai Mohsen Alqadami, Beadaa Mohammed, Anthony E. Stancombe, Nghia Nguyen-trong, Michael T. Heitzmann, Amin AbboshAbstract:An approach toward designing and building of a compact, low-profile, wideband, unidirectional, and conformal Imaging antenna for electromagnetic (EM) Head Imaging systems is presented. The approach includes the realization of a custom-made flexible high-permittivity dielectric substrate to achieve a compact sensing antenna. The developed composite substrate is built using silicon-based poly-di-methyl-siloxane (PDMS) matrix and microscale of aluminium oxide (Al2O3) and graphite (G) powders. Al2O3 and G powders are used as fillers with different weight-ratio to manipulate and control the dielectric properties of the substrate for attaining better matched with the human Head and reducing antenna’s physical size while keeping the PDMS flexibility feature. Using the custom-made substrate, a compact, wideband, and unidirectional on-body matched antenna for wearable EM Head Imaging system is realized. The antenna is configured as a multi-slot planar structure with four shorting pins, working as electric and magnetic dipoles at different frequency bands. The measured reflection coefficient (S11) shows an operating frequency band of 1–4.3 GHz. The time-average power density and the amplitude of the received signal inside the MRI-based realistic Head phantom demonstrate a unidirectional propagation and high-fidelity factor (FF) of more than 90%. An array of 13 antennas are fabricated and tested on a realistic 3-D Head phantom to verify the Imaging capability of the proposed antenna. The reconstructed images of different targets inside the Head phantom demonstrate the possibility of utilizing the conformal antenna arrays to detect and locate abnormality inside the brain using multistatic delay-multiply-and-sum beamforming algorithm.
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Flexible Quasi-Yagi antenna arrays for wearable electromagnetic Head Imaging based on polymer technology
2018 Australian Microwave Symposium (AMS), 2018Co-Authors: Abdulrahman Shueai Mohsen Alqadami, Konstanty S. Bialkowski, Amin AbboshAbstract:A flexible, low profile, compact and wideband planar quasi-Yagi antenna array is proposed for a wearable electromagnetic Head Imaging system. The array is designed on a low cost, high-flexibility, and robustness polymer polydimethylsiloxane (PDMS) substrate and is optimized to operate in a low microwave frequency band of 1.63 GHz–2.66 GHz. An array of 12 antennas is configured and embedded in a polymer-based 3D elliptical structure which is wearable. Numerical simulations using CST Microwave Studio are performed in free space, on a realistic (Hugo) human Head model, and under folded conditions. The simulations results show that the proposed antennas exhibit 51% impedance bandwidth, a maximum gain of 3 dB, more than 83% of radiating efficiency and > −14 dB mutual coupling between neighboring antennas.
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Compact 3-D Slot-Loaded Folded Dipole Antenna With Unidirectional Radiation and Low Impulse Distortion for Head Imaging Applications
IEEE Transactions on Antennas and Propagation, 2016Co-Authors: Ahmed Toaha Mobashsher, Amin AbboshAbstract:A compact 3-D antenna for microwave-based Head Imaging systems is presented. The antenna, which is fed by a coplanar waveguide, consists of a slot-loaded folded dipole structure with four furled sides. Because of the presence of stronger currents on the top layer and reflections from the slightly extended bottom layer, the antenna exhibits directional radiation in the frequency domain in both near and far fields. The transient response of the antenna is also analyzed. Despite the existence of multiple slot loading and folding in the proposed antenna, the investigation of the time domain responses reveals a directional low-distorted radiation (impulse fidelity factor of more than 80%) toward the boresight direction in both near and far fields. The antenna has the compact size and low profile, with respect to the lowest operating wavelength, of $0.29 \,\, \times \,\, 0.08$ , and 0.04, respectively, and 67% fractional bandwidth over 1.1–2.2 GHz. Since the antenna is designed to operate within an array for Head Imaging, a 16-element array of the antenna is tested in a realistic simulation environment to confirm a safe radiation exposure level. Finally, the array is employed on a realistic human Head model to successfully detect and locate a hemorrhagic brain injury.
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Hybrid Clutter Rejection Technique for Improved Microwave Head Imaging
IEEE Transactions on Antennas and Propagation, 2015Co-Authors: Ali Zamani, Amin AbboshAbstract:The accuracy of microwave Head Imaging is adversely affected by strong clutters that can completely mask the target response. To that end, different clutter removal techniques are modified for multistatic frequency-based Imaging. It is shown that some deficiencies of those methods in time domain, such as time overlapping, can be alleviated when they are modified for use in frequency domain. Based on the explored performance of different methods in the frequency domain, a hybrid technique, which combines the benefits of average subtraction and entropy-based filtering methods, is proposed. In this method, the average value of the multistatic scattered signals is subtracted from them at each frequency sample to remove late-stage clutters, whereas an entropy-based method is applied to mitigate early-stage strong clutters. The proposed technique is verified in realistic environments using simulations and experiments. The utilized system for verification is 1.1–3.2 GHz frequency-domain multistatic with an eight-element antenna array, and compact microwave transceiver. The simulations are performed on MRI-derived Head model, whereas the experiments are done on realistic artificial Head phantom. The obtained results from different locations and sizes of emulated brain injuries confirm the effectiveness of the proposed method in producing high quality images of the Head after mitigating the clutter.
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Realistic numerical Head model with tissues modeled using fourth-order Debye to test microwave systems for Head Imaging
2013 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2013Co-Authors: Phong Thanh Nguyen, S. Mustafa, Amin AbboshAbstract:Anatomically realistic numerical brain phantom is built using MRI images. The phantom considers the frequency dispersive properties of the Head biological tissues. To that end, a fourth-order Debye model is derived and included in the numerical model over the band from 0.5 GHz to 2.5 GHz, which is widely used in microwave-based Head Imaging as a reasonable compromise between penetration and resolution. The model is created using a combination of Matlab and CST Microwave Studio from MRI slices of a real patient. The Head phantom is comprised of a three-dimensional grid of 256×256×128 cubic voxels where the size of each voxel is 1.1 mm× 1.1 mm× 1.1 mm.
Tom Hayton - One of the best experts on this subject based on the ideXlab platform.
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po027 spontaneous cervical epidural haematoma presenting as thunderclap Headache case presentation
Journal of Neurology Neurosurgery and Psychiatry, 2017Co-Authors: Barbara Wysota, A. C. Williams, Tom HaytonAbstract:Thunderclap Headache is most commonly associated with subarachnoid haemorrhage or other acute intracranial pathology. It’s typically investigated with Head Imaging and lumbar puncture. We are presenting here the case of spontaneous cervical epidural haematoma manifesting as thunderclap Headache. This pathology could be missed by following standard investigations of thunderclap Headache and highlighting importance of through clinical history. 86 year old man presented to Emergency Department with thunderclap Headache and loss of consciousness. Patient developed severe occipital Headache while leaving the bath than lost consciousness. After waking up he was unable to stand up, his lower legs felt numb and weak. Headache gradually improved within 30 min. His CT Head after arrival to A and E didn’t show any acute intracranial pathology. CSF was normal, xantochromia was negative. Within 48 hours patient recovered almost completely. Was able to mobilise independently and was considered fit for discharge by medical team. After neurology review MRI scan of cervical spine was organised revealing spontaneous cervical epidural haematoma.
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PO027 Spontaneous cervical epidural haematoma presenting as thunderclap Headache – case presentation
Journal of Neurology Neurosurgery and Psychiatry, 2017Co-Authors: Barbara Wysota, A. C. Williams, Tom HaytonAbstract:Thunderclap Headache is most commonly associated with subarachnoid haemorrhage or other acute intracranial pathology. It’s typically investigated with Head Imaging and lumbar puncture. We are presenting here the case of spontaneous cervical epidural haematoma manifesting as thunderclap Headache. This pathology could be missed by following standard investigations of thunderclap Headache and highlighting importance of through clinical history. 86 year old man presented to Emergency Department with thunderclap Headache and loss of consciousness. Patient developed severe occipital Headache while leaving the bath than lost consciousness. After waking up he was unable to stand up, his lower legs felt numb and weak. Headache gradually improved within 30 min. His CT Head after arrival to A and E didn’t show any acute intracranial pathology. CSF was normal, xantochromia was negative. Within 48 hours patient recovered almost completely. Was able to mobilise independently and was considered fit for discharge by medical team. After neurology review MRI scan of cervical spine was organised revealing spontaneous cervical epidural haematoma.
A M Abbosh - One of the best experts on this subject based on the ideXlab platform.
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wearable electromagnetic Head Imaging system using flexible wideband antenna array based on polymer technology for brain stroke diagnosis
IEEE Transactions on Biomedical Circuits and Systems, 2019Co-Authors: Abdulrahman S M Alqadami, Konstanty S. Bialkowski, Ahmed Toaha Mobashsher, A M AbboshAbstract:Given the increased interest in a fast, portable, and on-spot medical diagnostic tool that enables early diagnosis for patients with brain stroke, a new approach of a wearable electromagnetic Head Imaging system based on the polymer material is proposed. A flexible low-profile, wideband, and unidirectional antenna array with electromagnetic band gap (EBG) and metamaterial (MTM) unit cells reflector is utilized. The designed antenna consists of a 4 × 4 radiating patch loaded with symmetrical extended open-ended U-slots and fed by combination of series and corporate transmission lines. A mushroom-like 10-EBG unit cell arrays are arranged around the feeding network to reduce surface waves, whereas 4 × 4 MTM unit cells are placed on the back-side of the antenna to enable unidirectional radiation. The antenna is designed and embedded on a multilayer low cost, low loss, transparent, and robust polymer poly-di-methyl-siloxane (PDMS) substrate and optimized to operate in contact with the human Head. The simulated and measured results show that the antenna has a fractional bandwidth of 53.8% (1.16–1.94 GHz), more than 80% of radiation efficiency, and satisfactory field penetration in the Head tissues with a safe specific absorption rate. An eight-element array is then configured on 300 × 360 × 4.1 mm3 PDMS material covering an average human Head size and used as a worn part of the Imaging system. A realistic-shaped 3-D specific anthropomorphic mannequin (SAM) Head phantom is used to verify the performance of the designed array. The Imaging results indicate the possibility of using the designed conformal array to detect a bleeding inside the brain using a confocal image algorithm.
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portable wideband microwave Imaging system for intracranial hemorrhage detection using improved back projection algorithm with model of effective Head permittivity
Scientific Reports, 2016Co-Authors: Ahmed Toaha Mobashsher, Ahmed Mahmoud, A M AbboshAbstract:Intracranial hemorrhage is a medical emergency that requires rapid detection and medication to restrict any brain damage to minimal. Here, an effective wideband microwave Head Imaging system for on-the-spot detection of intracranial hemorrhage is presented. The operation of the system relies on the dielectric contrast between healthy brain tissues and a hemorrhage that causes a strong microwave scattering. The system uses a compact sensing antenna, which has an ultra-wideband operation with directional radiation, and a portable, compact microwave transceiver for signal transmission and data acquisition. The collected data is processed to create a clear image of the brain using an improved back projection algorithm, which is based on a novel effective Head permittivity model. The system is verified in realistic simulation and experimental environments using anatomically and electrically realistic human Head phantoms. Quantitative and qualitative comparisons between the images from the proposed and existing algorithms demonstrate significant improvements in detection and localization accuracy. The radiation and thermal safety of the system are examined and verified. Initial human tests are conducted on healthy subjects with different Head sizes. The reconstructed images are statistically analyzed and absence of false positive results indicate the efficacy of the proposed system in future preclinical trials.
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3 d wideband antenna for Head Imaging system with performance verification in brain tumor detection
IEEE Antennas and Wireless Propagation Letters, 2015Co-Authors: Ahdi S Rezaeieh, Ali Zamani, A M AbboshAbstract:A 3-D slot-rotated antenna for a microwave Head- Imaging system is presented. The antenna is designed to have a wideband and unidirectional performance at the low microwave frequency band that are the requirements of the specified Imaging system. Starting from a traditional wide-slot antenna, several conventional techniques are applied to enhance its bandwidth and directivity while miniaturizing its size. In that regard, four series of staircase-shaped slots are applied to lower the operating frequency, whereas a folding process is used to enhance the directivity and reduce the overall size. In addition, two parasitic patches are connected to the slot area to increase the operating bandwidth. The final design has the dimensions of ${\hbox {0.11}} \lambda \times {\hbox {0.23}} \lambda \times {\hbox {0.05}} \lambda $ . ( $\lambda $ is the wavelength of the lowest measured operating frequency.) It has a measured VSWR fractional bandwidth of 87% (1.41–3.57 GHz) and a peak front-to-back ratio of 9 dB. To verify the suitability of the antenna in Head Imaging, it is connected to a wideband microwave transceiver and used to circularly scan an artificial Head phantom in $20^\circ$ angle steps in a monostatic mode. The collected backscattered data are then processed and used to generate an image that successfully shows brain tumors. The compact size, wide operating bandwidth, unidirectional radiation, and detection viability are merits of the presented antenna and the subsequent system.
