Followed Journals
Journal you Follow: 0
 
Sign Up to follow journals, search in your chosen journals and, optionally, receive Email Alerts when new issues of your Followed Journals are published.
Already have an account? Sign In to see the journals you follow.
Similar Journals
Journal Cover
IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology
Number of Followers: 1  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2469-7249 - ISSN (Online) 2469-7257
Published by IEEE Homepage  [228 journals]
  • [Front cover]
    • Abstract: Presents the front cover for this issue of the publication.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • [Front inside cover]
    • Abstract: Provides a listing of current staff, committee members and society officers.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • [Back inside cover]
    • Abstract: Presents the back inside cover of this issue of the periodical.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Passive Impedance Matching for Implanted Brain–Electrode Interfaces
    • Authors: Wei-Chuan Chen;Katrina Guido;Asimina Kiourti;
      Pages: 233 - 239
      Abstract: We propose a new technique for matching the high impedance of sub-cranial electrodes to wireless brain implants that is passive, highly tolerant of the dc offset voltage caused by the electrochemical reaction in the recording electrode, and complemented by an improved external interrogator design that exhibits reduced phase noise. As compared to previous wireless and batteryless brain implants, the proposed approach offers a remarkable improvement in sensitivity by 25 times. The proposed system consists of an external interrogator and a neuro-recorder implanted under the scalp. For operation, the interrogator sends a 2.4-GHz carrier signal to turn on the implant. This carrier self-biases a PNP Bipolar Junction Transistor (BJT) that enables matching to the recording electrode at frequency fneuro in a batteryless manner. Concurrently, the recorded neuropotentials (at frequency fneuro) pass through a Schottky diode that allows them to mix with the carrier and generate a 4.8 GHz ± fneuro modulated signal. The latter is then transmitted back to the interrogator for demodulation. To verify the implant's operation, in-vitro measurements are presented. Measurement results demonstrate that emulated neuropotentials as low as 200 μVpp can be detected at a 33-kΩ electrode impedance. As such, the proposed system presents a game-changing capability for a wide range of applications.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Selecting the Optimal Subset of Antennas in Hyperthermia Treatment
           Planning
    • Authors: Gennaro G. Bellizzi;Margarethus M. Paulides;Tomas Drizdal;Gerard C. van Rhoon;Lorenzo Crocco;Tommaso Isernia;
      Pages: 240 - 246
      Abstract: Hyperthermia treatment planning is a deeply patient-specific task which includes the optimal determination of the excitations of an array applicator. To enhance flexibility, various solutions exploiting different frequencies, antenna element, number, and applicator geometries have been proposed in the literature. Amongst them, increasing the frequency and the number of radiating elements have been effective for achieving more conformal heating. However, as each radiating element requires a power amplifier to control it, increasing the number of antennas considerably impacts the overall cost and complexity of the system. Accordingly, a procedure capable of selecting an optimal patient-specific subset of antennas from an oversized phased array applicator (with more antenna elements than available amplifiers) could help improve cost-effectiveness. In this study, we present an original approach, which allows improving performance by adaptively selecting the optimal subset of antennas to be activated for a given (redundant) applicator and a given patient. The proposed approach takes inspiration from the compressive sensing theory by embedding the sparsity promotion paradigm into a treatment planning procedure, which casts power deposition as a constrained convex optimization. Performances were demonstrated for the case of head and neck hyperthermia and benchmarked against the antenna selection procedure presently used in clinical practice.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Impact of Electrode Structure on RF-Induced Heating for an AIMD Implanted
           Lead in a 1.5-Tesla MRI System
    • Authors: Rui Yang;Jianfeng Zheng;Yu Wang;Ran Guo;Wolfgang Kainz;Ji Chen;
      Pages: 247 - 253
      Abstract: In this paper, the impact of the electrode structure on radio-frequency (RF) induced heating near an active implantable medical device implanted lead under magnetic resonance imaging exposure is investigated. The specific absorption rate (SAR) distributions and the temperature rises of the leads with different electrodes were assessed. It is shown that increasing the size of the lead electrode reduces the SAR distribution and temperature rise near the electrode. Our results indicate that a larger electrode size will reduce the magnitudes of the lead transfer function, subsequently reducing the heating effect near the electrode. Both numerical simulations and experimental measurements were performed to verify the effectiveness of a large electrode in mitigating the RF-induced heating.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Detection of Simulated Brain Strokes Using Microwave Tomography
    • Authors: Vanna Lisa Coli;Pierre-Henri Tournier;Victorita Dolean;Ibtissam El Kanfoud;Christian Pichot;Claire Migliaccio;Laure Blanc-Féraud;
      Pages: 254 - 260
      Abstract: Brain strokes are one of the leading causes of disability and mortality in adults in developed countries. Ischemic stroke (85% of total cases) and hemorrhagic stroke (15%) must be treated with opposing therapies, and thus, the nature of the stroke must be determined quickly in order to apply the appropriate treatment. Recent studies in biomedical imaging have shown that strokes produce variations in the complex electric permittivity of brain tissues, which can be detected by means of microwave tomography. Here, we present some synthetic results obtained with an experimental microwave tomography-based portable system for the early detection and monitoring of brain strokes. The determination of electric permittivity first requires the solution of a coupled forward-inverse problem. We make use of massive parallel computation from domain decomposition method and regularization techniques for optimization methods. Synthetic data are obtained with electromagnetic simulations corrupted by noise, which have been derived from measurements errors of the experimental imaging system. Results demonstrate the possibility to detect hemorrhagic strokes with microwave systems when applying the proposed reconstruction algorithm with edge preserving regularization.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Low-Cost Inkjet-Printed RFID Tag Antenna Design for Remote
           Healthcare Applications
    • Authors: Abubakar Sharif;Jun Ouyang;Yi Yan;Ali Raza;Muhammad Ali Imran;Qammer H. Abbasi;
      Pages: 261 - 268
      Abstract: This paper presents a low-cost, inkjet printed radio frequency identification (RFID) tag antenna for remote healthcare applications. The electrically small tag consists of nested-slot configuration and parallel strips. The tag antenna is exploited as a sensor by modifying its equivalent circuit to mitigate the effects of water, blood sample phantom, and the human body. As a result, the proposed RFID tag antenna with compact dimensions of 40 × 14 mm2, features a conjugate match with Impinj R6 RFID chip ranging from 890 to 937 MHz. Moreover, this tag has a read range of 3 m, 2.5 m, and 1.5 m on the water bottle, intravenous (IV) solution and blood bag, respectively. However, the read range of RFID tag on an empty water bottle or IV solution bag is 0.5 m. By comparing the read range of tag on empty and solution filled IV bags, the proposed tag was used as a water proximity sensor. Experimental testing of the tag is performed for sensing the level of the IV solution. Also, this tag is tested after mounting on the liquid mixture (a mixture of salt and sugar is used as a phantom to mimic the blood) filled plastic bags, which leads to a low-cost solution for blood storage management. Experimental results show a good agreement of the proposed tag toward its use in healthcare applications, which leads to better healthcare facilitation regarding cost, time, and care.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Effects of Coaxial-Lateral and Coaxial-Angular Displacements on Link
           Efficiency of a Wirelessly Powered Optogenetic Implant: Design, Modeling,
           and Experimental Validation
    • Authors: Dipon K. Biswas;Nishat T. Tasneem;Ifana Mahbub;
      Pages: 269 - 275
      Abstract: In recent years, the wireless power transfer (WPT) system has evolved tremendously as a means to deliver power to miniaturized implantable sensors. Efficiently delivering power to implants is a challenge due to the loose coupling between the transmitter and receiver coils because of the various displacements (coaxial, lateral, and angular). The coupling coefficient deteriorates significantly due to the displacements, thus decreasing the overall power transfer efficiency of the system. In this paper, we present an analysis and modeling of the effects of various displacements on the efficiency and the overall performance of a miniaturized WPT system designed for an optogenetic implant. To emulate the tissue media inside a human head, skin, skull, and gray matter layers are theoretically modeled using dielectric properties, and simulation models are developed using Ansys high-frequency structure simulator (HFSS) software. The propagation loss and the link efficiency are modeled and simulated as a function of various displacement combinations. To validate the theoretical and simulation models, the WPT system is characterized in various displacement conditions using chicken breast as the tissue media. The measurement results also show a good agreement with the simulation results, thus providing estimation for the misalignment tolerance range for given specifications. The efficiency performance analysis of the proposed WPT system for various worst-case scenarios also provides a preliminary model for designing a closed-loop wireless power delivery regulation scheme in the future.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Numerical Study to Probe Effects of Strain Energy on Pore Formation and
           Their Density Distribution
    • Authors: Hao Qiu;Xianping Wang;Ravindra Prabhakar Joshi;Wenbing Zhao;
      Pages: 276 - 283
      Abstract: Electroporation is an important pathway to transport material such as drugs, genes, and ions into biological cells. Here, we perform simulations to predict the pore density and transmembrane potential due to high-intensity, ultra-short duration electrical pulses. Explicit account is taken of the strain energy. Our continuum model results demonstrate that pore density increases rapidly and nonlinearly with respect to the transmembrane potential. The numerical calculations also show that average strain energy can work towards membrane stabilization and that the energy needed to form a two-pore system would be smaller than a one pore system. This differential between the oneand two-pore scenarios is predicted to increase monotonically with pore radius. It is also predicted that the membrane would likely produce multiple nanopores of high density, as hypothesized in the literature. The potential for pore formation and transient leak-out would both likely reduce the membrane tension, favoring smaller multiple nanopores.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Portable Microwave Head Imaging System Using Software-Defined Radio and
           Switching Network
    • Authors: Anthony Edgar Stancombe;Konstanty S. Bialkowski;Amin M. Abbosh;
      Pages: 284 - 291
      Abstract: 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.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Feasibility Study of Hydration Monitoring Using Microwaves–Part 1: A
           Model of Microwave Property Changes With Dehydration
    • Authors: David C. Garrett;Elise C. Fear;
      Pages: 292 - 299
      Abstract: Dehydration is a prevalent condition that can have profound health consequences. If detected early, it can often be treated by oral fluid replacement (drinking or eating). However, existing assessment techniques lack the accuracy and/or convenience for ongoing monitoring, motivating the development of novel methods. We propose using low-power microwave measurements (2-12 GHz) at the extremities to monitor human hydration, relying on the strong relationship between dielectric properties of tissues and water content. Electromagnetic simulations of realistic models are used to explore changes in microwave signals transmitted through the forearm to changes in hydration. Tissue properties are adjusted according to expected changes in water content, and average dielectric properties are estimated from signals transmitted through the arm by ultrawideband antennas placed in contact with the tissues. A causal relationship between weight loss due to water loss and dielectric permittivity is found in human simulation models. Little relationship is found with conductivity. The theoretical groundwork for hydration assessment with microwaves is developed through a model which relates changes in total body water content with changes in microwave properties at the extremities. This model could be useful for monitoring hydration in at-risk populations such as older adults and athletes.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • Feasibility Study of Hydration Monitoring Using Microwaves–Part 2:
           Measurements of Athletes
    • Authors: David Christopher Garrett;Jared R. Fletcher;David B. Hogan;Tak Shing Fung;Elise C. Fear;
      Pages: 300 - 307
      Abstract: Hydration is a key consideration for athletes, where even mild levels of dehydration may negatively impact performance. Existing methods of assessment are either inaccurate or impractical for use in field settings, motivating the search for new approaches. Extremity microwave measurement is a promising method for ongoing hydration monitoring, owing to the inherent differences in dielectric properties with varying tissue water content. This paper reports on a feasibility study of in vivo hydration assessment using microwave measurements in athletes undergoing acute water loss during exercise. We developed and then tested a system for performing reliable microwave property estimation at the forearm. This system was used to measure hydration status in varsity wrestlers before and after a training session. A relationship between estimated permittivity and body weight change due to water loss was found, showing promise for the use of microwaves to assess hydration status. No significant relationship with attenuation was found. A novel method of assessing changes in hydration status is described, which may be of practical use for athletes in guiding fluid replacement during and after exercise.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
  • 2019 Index IEEE Journal of Electromagnetics, RF and Microwaves in Medicine
           and Biology Vol. 3
    • Pages: 308 - 317
      Abstract: This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's name. The primary entry includes the co-authors' names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author's name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index.
      PubDate: Dec. 2019
      Issue No: Vol. 3, No. 4 (2019)
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 3.229.118.253
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-