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Title: ACES Journal June 2016 Cover
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
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Title: ACES Journal June 2016 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 129 KB

Title: ACES Journal June 2016 Full
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
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Title: A Single-Channel Non-Orthogonal I/Q RF Sensor for Non-Contact Monitoring of Vital Signs
Abstract: In order to remotely monitor the activities of heartbeat, respiration and body movement, this article designed and implemented a single-channel nonorthogonal in-phase/quadrature (I/Q) RF sensor, which works at the central frequency of 2.4 GHz. The designed RF sensor is based on a printed circuit board (PCB) antenna. Taking into account low cost, simple structure and easy fabrication, the antenna is designed and implemented with a special broad-band microstrip-tocoplanar strip line Balun structure by combining the transmitter with the receiver on a PCB to form one single antenna system. The gain of the sensor is 7.7 dB. The return loss is -22.7 dB at 2.4 GHz and the directionality of the antenna is satisfactory for monitoring vital signs. It has been validated that the designed sensor can detect the respiration, heartbeat and body movement accurately in comparison with the signals acquired by respiration sensor and pulse sensor.
Author(s): H. Bo, L. Xu, L. Hao, Y. Dou, L. Zhou, W. Yu
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
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Title: AMC Integrated Textile Monopole Antenna for Wearable Applications
Abstract: In this paper, performance of monopole textile antenna integrated with a flexible artificial magnetic conductor (AMC) surface is presented. The integrated antenna is designed for operating within the 2.45 GHz Industrial, Scientific and Medical (ISM) band. The addition of AMC is to reduce the backward radiation toward the human body and increase the antenna gain. Characteristics of the AMC antenna based on simulation and measurement results under different bending conditions have been studied and presented to validate the antenna for its usefulness in wearable applications. Besides, the causes that lead to the discrepancies between simulations and measurements are discussed.
Author(s): A. Alemaryeen, S. Noghanian
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 678 KB

Title: A Communication Link Analysis Based on Biological Implant Wireless Body Area Networks
Abstract: The rapid growth in remote healthcare services and biomedical demands has seen novel developments in wireless body area networks (WBANs). The WBAN can be seen as an integration of intelligent networks, which permits devices and sensors to work together to obtain a series of critical physiological parameters, such as blood flow velocity and heartbeat frequency. Analysis of WBAN radio frequency communication systems is the key factor and the critical research challenge that determines system performance, such as achievable transmission distance, data rate and so forth. The human head is an area of particular potential in WBAN design that is worthy of attracting more attention than its limited literature to date. This paper is primarily focused on the one of the most detailed comprehensive multi-modal imaging-based anatomical human head models. This is a multimodal imaging-based detailed anatomical model, denoted by the acronym MIDA, this features 153 structures at a high resolution of up to 500 ?m, including numerous distinct muscles, bones and skull layers in the license-free 2.4 GHz industrial, scientific, and medical (ISM) band. It presents and compares a set of advanced simulation methods and then proposes a path loss simulation flat phantom, semiempirical path loss models for typical homogeneous tissues and the anatomical human head MIDA model. The bit error rate (BER) performances of the MIDA model fading channel using binary phase shift keying (BPSK) and pulse-amplitude modulation (PAM) are obtained. Furthermore, achievable transmission distances for several data rates for predetermined acceptable BERs are accomplished. The results show that PAM promises longer transmission distances than BPSK when using both high and low data rates. The proposed communication systems can be applied to optimize implantation communication system scenarios and biotelemetry applications.
Author(s): Y. Liao, M. S. Leeson, M. D. Higgins
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
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Title: An Efficient Algorithm for SAR Evaluation from Anatomically Realistic Human Head Model Using DGTD with Hybrid Meshes
Abstract: In this paper, an efficient and fast algorithm is proposed to analyze the specific absorption rate (SAR) in the anatomically realistic human head model with voxel data format exposed a handset antenna. The algorithm is based on the discontinuous Galerkin timedomain (DGTD) method with conformal region division and hybrid meshes. The proposed algorithm is done by dividing the computational domain into a sub-region with head model and a sub-region with handset antenna. As the realistic head model is voxel data format, the voxel-based meshes are used to divide the sub-region with head model. The tetrahedral meshes are used to divide the antenna, and are suitable for antennas with curved features and thin objects. And the pyramid meshes are used to connect voxel-based mesh and tetrahedral mesh regions. The accuracy and efficiency of the proposed algorithm are verified by comparing numerical results with analytical solutions.
Author(s): L. Zhao, G. Chen, W. Yu
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 888 KB

Title: Assessment of the Electric Field Induced by Deep Transcranial Magnetic Stimulation in the Elderly Using H-Coil
Abstract: The recent advancements in the design of TMS coils to reach specific cortical and subcortical regions have allowed the treatment of various neuropsychiatric disorders, whose prevalence increases with age. This could be also due to the anatomical and morphological changes with age of the brain tissues, such as the atrophy that characterizes the elderly cortex. This study provides a description of the electric field, the main engine of the stimulation, distribution induced in specific cerebral tissues. That was performed by comparing, making use of computational electromagnetic techniques, the E distributions in two human models of different ages (34 and 84 years-old males), the older one showing cortical atrophy in the prefrontal lobe. The analysis of the parameters describing the spread of the electric field distribution shows that the H1 coil is able to induce in the prefrontal cortex an E amplitude higher than the neural threshold and with a widespread distribution in both models, with a slight prevalence on the younger one. On the contrary, the maximum E penetration depth and the consequent capability to reach deeper targets in the brain, is slightly higher for the elderly model.
Author(s): S. Fiocchi, Y. Roth, A. Zangen, P. Ravazzani, M. Parazzini
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 674 KB

Title: Stochastic Sensitivity in Homogeneous Electromagnetic-Thermal Dosimetry Model of Human Brain
Abstract: In this work we examined how the variability in the brain morphology and the tissue properties affect the assessment of the homogeneous human brain exposed to high frequency electromagnetic (EM) field. Using the deterministic EM-thermal modeling and the stochastic theoretical basis we have studied the effects of these uncertainties on the maximum induced electric field, maximum local Specific Absorption Rate (SAR), average SAR, maximum temperature and the maximum temperature increase, respectively. The results show a good convergence of stochastic technique and an assessment of mean and variance of outputs for the incident plane wave of 900 MHz.
Author(s): M. Cvetkovic, S. Lallechere, K. El Khamlichi Drissi, P. Bonnet, D. Poljak
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 1118 KB

Title: Sensitivity Analysis and Tipping Calibration of A W-band Radiometer for Radiometric Measurements
Abstract: This paper deals with the sensitivity analysis and tipping calibration of a developed W-band radiometer system for radiometric measurements. Initially the equivalent integration time of the cascaded hardware and software integrators is derived and the radiometer sensitivity is then analyzed based on the established system measurement equation. Secondly, the applicable tipping calibration of the W-band radiometer is investigated and optimized to reduce calibration errors according to the system parameters. Sensitivity measurement and tipping calibration experiments of the developed W-band radiometer are conducted. The preliminary results show that the radiometer sensitivity is 0.51 K with an integration time of 1 s, and the tipping calibration has a better accuracy than the liquid nitrogen calibration, with a maximum difference of 2.5 K between both of the calibration methods.
Author(s): L. Wu, S. Peng, Z. Xiao, J. Xu
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 585 KB

Title: Scalable GPU-Parallelized FDTD Method for Analysis of Large-Scale Electromagnetic Dosimetry Problems
Abstract: A massively parallel finite-difference timedomain (FDTD) method using a GPU cluster of TSUBAME system has been developed for numerical exposure of a human body to electromagnetic fields. We have also developed and implemented a novel approach for tracing total energy absorbed into a human body in our parallel FDTD code. Our developed FDTD code has shown a strong scalability using 216 nodes and 648 GPUs in total with a high capability to calculate over ten billion cells per second. Whole-body specific absorption rate (SAR) at 200 MHz, as well as its distribution, of a human body with a 0.5 mm resolution with 40000 time steps was found in less than approximately three hours, showing the availability of the method for large-scale EM dosimetry problems.
Author(s): J. C. K. Wake, S. Watanabe
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 937 KB

Title: Suppression of Surface Currents at Microwave Frequency Using Graphene- Application to Microwave Cancer Treatment
Abstract: In this work we consider the problem of surface currents suppression using graphene in the context of microwave cancer treatment. Most of the research on graphene has been focused on its applications at terahertz frequencies, and not at microwave frequencies. The use of microwave cancer ablation technique using a coaxial slot antenna is being limited because of the existence of surface currents which lead to the heating of the healthy tissues along its outer surface. In this work we propose to use graphene which is a single-atom sheet of carbon, as a solution to prevent the propagation of surface currents on the outer conductor of the coaxial antenna. We show that by properly designing and tuning the conductivity of the graphene layer, we can not only suppress the surface currents, but also control the amount of energy deposited in the surrounding tissue.
Author(s): H. Acikgoz, R. Mittra
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
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Title: Joint L1 and Total Variation Regularization for Magnetic Detection Electrical Impedance Tomography
Abstract: Magnetic detection electrical impedance tomography (MDEIT) is an imaging modality that aims to compute the cross-sectional distribution of the conductivity of a volume from the magnetic flux density surrounding the object. Owing to the Biot-Savart law, the MDEIT inverse problem is inherently ill-conditioned making image reconstruction highly susceptible to the effects of noise and numerical errors. Appropriate priors or penalties are needed to facilitate reconstruction and to restrict the search space to a specific solution set. The images have the sparsity property and sharp variations. Consequently, this paper presents an approach involving a combination of the L1 and total variation norm penalties, the former to suppress spurious background signals and enforce sparsity and the latter to preserve local smoothness and piecewise constancy in the MDEIT reconstructed images. The primal dual-interior point method (PD-IPM) for minimizing the joint L1–TV penalty was used in the paper. The method was validated by using MDEIT simulated data and experimental data in comparison with the performances of the L2, L1 and total variation norm penalty-based approaches. The results show that the joint L1–TV regularized algorithm preserves sparsity property, local smoothness and piecewise constancy, leading to improvements in the localization of the reconstructed images in MDEIT.
Author(s): L. Hao, L. Xu
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 741 KB

Title: Membrane Conductance Analysis on Single-cell Electroporation with Electrolyte-filled Capillary
Abstract: Single-cell electroporation with electrolytefilled capillary is a selective technique that affects the target cell without any consequences for the neighbouring cells. Inhomogeneous electric field caused by interaction of capillary, cell and environment in the experiment make the optimization setup difficult for DNA transfection efficiency. A electroporation model of membrane conductivity with experimental parameters was used to analyze the influence of cell-to-tip distance, cell-capillary dimensions relation, electrolyte and cytoplasm conductivity, and strength of the pulses on electroporation. Simulation results demonstrate that the nonlinear electric field distribution on cell membrane depends on tip-to-cell distance and may be the cause of cell survival. The electroporation with capillary are affected by the external medium, relation between the cell and capillary radius, tip-to-cell distance, and strength of the applied potential.
Author(s): J. Anselmo, L. C. Ramos, J. L. B. Marques, F. R. M. B. Silva, D. O. H. Suzuki
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 736 KB

Title: A Practical UWB Microwave Imaging System Using Time-Domain DORT for Tumor Detection
Abstract: In this paper Time Reversal (TR) and Decomposition of Time Reversal operator (DORT) methods are employed in an Ultra-WideBand (UWB) microwave imaging system. The possibility of multiple tumor detection in using selective focusing DORT is investigated and a number of improvements are proposed in DORT algorithm. A practical UWB imaging system for tumor-like object detection consisting of just two revolving UWB antennas is then introduced. The proposed system does not need costly switches or network analyzers as it just uses a UWB transceiver to acquire the required time domain signals. Challenging problems of this system are addressed and their solutions are proposed and vindicated through both simulations and measurements carried out on a simple model by using an experimental setup. The proposed system is suitable for different applications such as breast cancer and tumor detection where high accuracy and resolution is necessary.
Author(s): S. Sadeghi, R. Faraji-Dana
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 4599 KB

Title: Image Reconstruction Based on the Anatomical Information for Magnetic Resonance Electrical Impedance Tomography
Abstract: Magnetic resonance electrical impedance tomography (MREIT) is a noninvasive modality to visualize the internal electrical conductivity distribution of an electrically conductive object using a magnetic resonance imaging (MRI) scanner. The impedance tomography step may provide valuable additional information that cannot be recovered from the MR reconstruction. Previous research has been mostly performed on the reconstruction algorithms and the measurement system. However, the anatomical information provided by the MR images is not in full use. This paper proposes an image reconstruction method based on anatomical information which provides the prior knowledge. The sensitivity algorithm with generalized minimum residual (GMRES) is proposed to reconstruct conductivity image. Simulations of a realistic geometry leg model are performed to show that our approach is not only capable of achieving high accuracy, but also able to improve the speed of the image reconstruction. At the end, a preliminary phantom experiment is presented, illustrating the feasibility of this proposed method.
Author(s): L. Hao, L. Xu, B. Yang, G. Li
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 607 KB

Title: Internal Homogenization of Biological Tissues for Electromagnetic Dosimetry
Abstract: In this paper, the internal homogenization method is introduced to determine the effective physical properties (permittivity and conductivity) of biological tissues. This method is performed on a 2D child head model obtained from MRI data. An original procedure where the complex 2D head model is represented as a multilayered circular structure is employed to retrieve the effective medium parameters. Results obtained with the proposed internal homogenization concept are compared with those obtained from the original heterogeneous model (with 4 tissues) and effective medium theories such as Maxwell-Garnett and Polder van Santen.
Author(s): H. Acikgoz
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 1058 KB

Title: Compact Implantable Rectenna with Light-Emitting Diode for Implantable Wireless Optogenetics
Abstract: In this paper, a compact rectenna which is capable to operate at 2.45 GHz for wireless implanted optogenetic stimulation is proposed. The rectenna consists of a monopole antenna and a rectifier circuit which drives the on-board blue light-emitting diode (LED). The presented rectenna is fabricated on 50 ?m liquid crystalline polymer (LCP) substrate and has a dimension of 7 mm × 7.2 mm. The measured results of the rectenna embedded in the pork shows that the integrated LED can be lit wirelessly under the maximum permissible human exposure limit in controlled environments.
Author(s): Y. Xu, Y. Lan, Y. Qiu, R. Xu
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 665 KB

Title: Multimodal Medical Image Fusion Using Dual-Tree Complex Wavelet Transform (DTCWT) with Modified Lion Optimization Technique (mLOT) and Intensity Co-Variance Verification (ICV)
Abstract: Image fusion is place as a key role in medical image investigation and preparation of treatments for bio-medical research and clinical diagnosis. The most incentive is fuse to capture a large amount of vital information from the input images to have its output image. In this paper, a well-organized multimodal medical image fusion approach is obtainable to fuse computer tomography (CT) and magnetic resonance image (MRI). The significant co-efficient of source images are line up through the dual-tree complex wavelet transform (DTCWT), followed by unit of low and high frequency components. Two completely different proposed fusion rules based on weighted fusion rule, the weights are optimized by modified lion optimization technique (mLOT) and intensity co-variance verification (ICV) are used to fuse the low and high frequency coefficient. The fused image is reconstructed by inverse DTCWT with all amalgamate co-efficient. To prove the potency of the new approach is greater than the wellknown standard algorithm, experiments are conducted. Based on experimental comparison and proposed approach, the better results are fused image quality are obtained. The studies of qualitative and quantitative metrics are clearly demonstrated that the new approach is to display the high superior than the present.
Author(s): C. G. Ravichandran, R. Selvakumar
File Type: Journal Paper
Issue:Volume: 31      Number: 6      Year: 2016
Download Link:Click here to download PDF     File Size: 1383 KB