Pub Date : 2023-04-27DOI: 10.1109/JERM.2023.3267659
Gaetano Chirico;Claudio D'Elia;Nicola D'Ambrosio;Rita Massa
Seed priming is a physiological seed enhancement method for overcoming poor and erratic seed germination in many crop and flowering plants. Magnetopriming is a pre-sowing seed treatment with magnetic field that appears as a promising method to improve seed performances. This paper presents a cost-efficient design and optimization of an exposure system for magnetopriming treatments. The proposed static magnetic field applicator is modelled and designed with the aid of commercial software. The prototype is realized and tested based on the best set of geometry parameters for optimum performance, in terms of strength and high homogeneity of the magnetic flux density in the Region of Interest. Both analytical and measurement results are found to be in good agreement with the simulated results. The system is low cost, environmentally friendly and easy to operate. It allows seed treatments at different strengths with high homogeneity within the samples. In this way, the treatments can be carried out following good practice requirements strongly recommended for a high quality bioelectromagnetic research to assure reliability and reproducibility of the experiments.
{"title":"Design and Evaluation of an Applicator for Magnetopriming Treatments","authors":"Gaetano Chirico;Claudio D'Elia;Nicola D'Ambrosio;Rita Massa","doi":"10.1109/JERM.2023.3267659","DOIUrl":"https://doi.org/10.1109/JERM.2023.3267659","url":null,"abstract":"Seed priming is a physiological seed enhancement method for overcoming poor and erratic seed germination in many crop and flowering plants. Magnetopriming is a pre-sowing seed treatment with magnetic field that appears as a promising method to improve seed performances. This paper presents a cost-efficient design and optimization of an exposure system for magnetopriming treatments. The proposed static magnetic field applicator is modelled and designed with the aid of commercial software. The prototype is realized and tested based on the best set of geometry parameters for optimum performance, in terms of strength and high homogeneity of the magnetic flux density in the Region of Interest. Both analytical and measurement results are found to be in good agreement with the simulated results. The system is low cost, environmentally friendly and easy to operate. It allows seed treatments at different strengths with high homogeneity within the samples. In this way, the treatments can be carried out following good practice requirements strongly recommended for a high quality bioelectromagnetic research to assure reliability and reproducibility of the experiments.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 3","pages":"245-250"},"PeriodicalIF":3.2,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7397573/10226431/10109786.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50291932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-18DOI: 10.1109/JERM.2023.3265510
Jochen Moll;Teresa Slanina;Jonathan Stindl;Thomas Maetz;Duy Hai Nguyen;Viktor Krozer
Conventional approaches for microwave breast tumor detection are limited by the imaging resolution due to the low operating frequency. The objective of this work is to provide a proof of concept for radar-based detection of breast tumors in K-band using the temperature-dependent permittivity of the tissue for contrast enhancement. The innovation of this work is given by i) investigating higher microwave frequencies for breast cancer diagnostics and improved resolution; ii) exploiting variations in tissue temperature as a non-invasive approach for contrast-induced radar imaging eliminating the need for contrast agents such as nanoparticles; iii) using a well-defined setup with the breast compressed similar to mammography; iv) eliminating the need for coupling liquid through the usage of ultra-wideband bow-tie antennas operating from 16.55 to 40 GHz for a reflection coefficient lower than −10 dB; v) validating the experimental findings through numerical modelling. The experimental setup in this work consists of a single-pixel transmission setup with the antennas placed in a 3D printed container. Two different tissue mimicking phantoms have been studied that both model the temperature-dependent permittivity of biological tissue. The first phantom represents homogeneous fatty tissue properties and the second phantom simulates fatty tissue with a tumor inclusion. A uniform phantom warming is realized through a water bath combined with a continuous monitoring of the phantoms temperature. We show that a homogeneous phantom without tumor can be distinguished from a heterogeneous phantom with tumor in the temperature range of 28 $^circ$ C to 38 $^circ$ C.
{"title":"Temperature-Induced Contrast Enhancement for Radar-Based Breast Tumor Detection at K-Band Using Tissue Mimicking Phantoms","authors":"Jochen Moll;Teresa Slanina;Jonathan Stindl;Thomas Maetz;Duy Hai Nguyen;Viktor Krozer","doi":"10.1109/JERM.2023.3265510","DOIUrl":"https://doi.org/10.1109/JERM.2023.3265510","url":null,"abstract":"Conventional approaches for microwave breast tumor detection are limited by the imaging resolution due to the low operating frequency. The objective of this work is to provide a proof of concept for radar-based detection of breast tumors in K-band using the temperature-dependent permittivity of the tissue for contrast enhancement. The innovation of this work is given by i) investigating higher microwave frequencies for breast cancer diagnostics and improved resolution; ii) exploiting variations in tissue temperature as a non-invasive approach for contrast-induced radar imaging eliminating the need for contrast agents such as nanoparticles; iii) using a well-defined setup with the breast compressed similar to mammography; iv) eliminating the need for coupling liquid through the usage of ultra-wideband bow-tie antennas operating from 16.55 to 40 GHz for a reflection coefficient lower than −10 dB; v) validating the experimental findings through numerical modelling. The experimental setup in this work consists of a single-pixel transmission setup with the antennas placed in a 3D printed container. Two different tissue mimicking phantoms have been studied that both model the temperature-dependent permittivity of biological tissue. The first phantom represents homogeneous fatty tissue properties and the second phantom simulates fatty tissue with a tumor inclusion. A uniform phantom warming is realized through a water bath combined with a continuous monitoring of the phantoms temperature. We show that a homogeneous phantom without tumor can be distinguished from a heterogeneous phantom with tumor in the temperature range of 28 \u0000<inline-formula><tex-math>$^circ$</tex-math></inline-formula>\u0000C to 38 \u0000<inline-formula><tex-math>$^circ$</tex-math></inline-formula>\u0000C.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 3","pages":"251-257"},"PeriodicalIF":3.2,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50404731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-11DOI: 10.1109/JERM.2023.3264116
Prince M. Atsu;Zachary Nicolella;Maya Webb;Nicholas Brady;Eunice Nepomuceno;Connor Mowen;Gary L. Thompson
Measurement of molecular transport through tissues can be performed using gel electrophoresis techniques but is subject to substantial changes of temperature over the course of an experiment due to conversion of electrical to thermal energy. The objective of this study is to mitigate thermal generation and accumulation while determining the electrophoretic mobility of charged molecules within annulus fibrosus cartilage tissue. By using electrical pulses as compared to direct current (DC), less total energy is input and more heat can dissipate in a given amount of time. Temperature measurements confirm that use of DC leads to higher rates of temperature change during electrophoresis, with Joule heating responsible for the thermal rise. The measured electrophoretic mobilities of two small, charged dye molecules are found to be similar among DC, square and sawtooth pulsed electrophoresis. One significant difference occurs between square and sawtooth pulses for the dye that interacts less with the cartilage tissue. Results herein suggest that accurate measurements with reduced temperature changes of thermally-sensitive tissues can be made using pulsed electrophoresis, which can lead to a better understanding of molecular transport under physiological conditions.
{"title":"Electrophoretic Transport Through Fibrocartilage Driven by Square and Sawtooth Pulses With Decreased Joule Heating","authors":"Prince M. Atsu;Zachary Nicolella;Maya Webb;Nicholas Brady;Eunice Nepomuceno;Connor Mowen;Gary L. Thompson","doi":"10.1109/JERM.2023.3264116","DOIUrl":"https://doi.org/10.1109/JERM.2023.3264116","url":null,"abstract":"Measurement of molecular transport through tissues can be performed using gel electrophoresis techniques but is subject to substantial changes of temperature over the course of an experiment due to conversion of electrical to thermal energy. The objective of this study is to mitigate thermal generation and accumulation while determining the electrophoretic mobility of charged molecules within annulus fibrosus cartilage tissue. By using electrical pulses as compared to direct current (DC), less total energy is input and more heat can dissipate in a given amount of time. Temperature measurements confirm that use of DC leads to higher rates of temperature change during electrophoresis, with Joule heating responsible for the thermal rise. The measured electrophoretic mobilities of two small, charged dye molecules are found to be similar among DC, square and sawtooth pulsed electrophoresis. One significant difference occurs between square and sawtooth pulses for the dye that interacts less with the cartilage tissue. Results herein suggest that accurate measurements with reduced temperature changes of thermally-sensitive tissues can be made using pulsed electrophoresis, which can lead to a better understanding of molecular transport under physiological conditions.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 3","pages":"210-215"},"PeriodicalIF":3.2,"publicationDate":"2023-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50291938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.1109/JERM.2023.3278151
{"title":"IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology Publication Information","authors":"","doi":"10.1109/JERM.2023.3278151","DOIUrl":"https://doi.org/10.1109/JERM.2023.3278151","url":null,"abstract":"","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 2","pages":"C2-C2"},"PeriodicalIF":3.2,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7397573/10138047/10138073.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50382708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.1109/JERM.2023.3278155
{"title":"IEEE Journal of Electromagnetics, RF, and Microwaves in Medicine and Biology About this Journal","authors":"","doi":"10.1109/JERM.2023.3278155","DOIUrl":"https://doi.org/10.1109/JERM.2023.3278155","url":null,"abstract":"","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 2","pages":"C3-C3"},"PeriodicalIF":3.2,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7397573/10138047/10138048.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50238624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-27DOI: 10.1109/JERM.2023.3256705
Dipon K. Biswas;Nabanita Saha;Arnav Kaul;Ifana Mahbub
Miniaturization of the neuromodulation system is important for non-invasive or sub-invasive optogenetic application. This work presents an optimized wireless power transfer (WPT) system integrated with an on-chip rectification circuitry and an off-chip stimulation circuitry for optogenetic stimulation of freely moving rodents. The proposed WPT system is built using parallel transmitter (TX) coils on printed circuit board (PCB) and wire-wound based receiver (RX) coil followed by a seven-stage voltage doubler and a low dropout regulator (LDO) circuit designed in 180 nm standard Complementary Metal Oxide Semiconductor (CMOS) process. A pulse stimulation is used to stimulate the neurons which is generated using a commercially available off-the-shelf (COTS) components based oscillator circuit. The intensity of the stimulation is controlled by using a COTS based LED driver circuit which controls the current through the $mu$ LED. The total dimension of the RX coil is 8 mm × 3.4 mm. The maximum power transfer efficiency (PTE) of the proposed WPT system is $sim$ 35% and the power conversion efficiency (PCE) of the rectifier is 52%. The proposed system with reconfigurable stimulation frequency is suitable for exciting different brain areas for long-term health monitoring.
{"title":"Semi-Implantable Wireless Power Transfer (WPT) System Integrated With On-Chip Power Management Unit (PMU) for Neuromodulation Application","authors":"Dipon K. Biswas;Nabanita Saha;Arnav Kaul;Ifana Mahbub","doi":"10.1109/JERM.2023.3256705","DOIUrl":"https://doi.org/10.1109/JERM.2023.3256705","url":null,"abstract":"Miniaturization of the neuromodulation system is important for non-invasive or sub-invasive optogenetic application. This work presents an optimized wireless power transfer (WPT) system integrated with an on-chip rectification circuitry and an off-chip stimulation circuitry for optogenetic stimulation of freely moving rodents. The proposed WPT system is built using parallel transmitter (TX) coils on printed circuit board (PCB) and wire-wound based receiver (RX) coil followed by a seven-stage voltage doubler and a low dropout regulator (LDO) circuit designed in 180 nm standard Complementary Metal Oxide Semiconductor (CMOS) process. A pulse stimulation is used to stimulate the neurons which is generated using a commercially available off-the-shelf (COTS) components based oscillator circuit. The intensity of the stimulation is controlled by using a COTS based LED driver circuit which controls the current through the \u0000<inline-formula><tex-math>$mu$</tex-math></inline-formula>\u0000LED. The total dimension of the RX coil is 8 mm × 3.4 mm. The maximum power transfer efficiency (PTE) of the proposed WPT system is \u0000<inline-formula><tex-math>$sim$</tex-math></inline-formula>\u000035% and the power conversion efficiency (PCE) of the rectifier is 52%. The proposed system with reconfigurable stimulation frequency is suitable for exciting different brain areas for long-term health monitoring.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 2","pages":"193-200"},"PeriodicalIF":3.2,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50238623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.1109/JERM.2023.3278473
Marco Mercuri;Ping Jack Soh;Pouya Mehrjouseresht;Felice Crupi;Dominique Schreurs
Fall incidents represent a major public health problem among elderly people. This resulted in a significant increase of the number of investigated systems aiming at detecting falls promptly. In this respect, in this work, a biomedical radar system is proposed for remote real-time fall detection and indoor localization. The system, consisting of a sensor and a base station, combines radar and wireless communication techniques, and uses a data processing technique to distinguish between fall events and normal movements. The classification, based on a Least-Square Support Vector Machine (LS -SVM), combined with the sliding window principle allows to perform fall detection in real-time. Moreover, it is capable to localize the subjects when the fall incident has been detected. The in-vivo validation showed a high success rate in detecting fall events, with a maximum delay of 340 ms. Moreover, a maximum mean absolute errors (MAE) of 3.8 cm and a maximum root-mean-square error (RMSE) of 7.5 cm were reported in measuring the subject's absolute distance.
{"title":"Biomedical Radar System for Real-Time Contactless Fall Detection and Indoor Localization","authors":"Marco Mercuri;Ping Jack Soh;Pouya Mehrjouseresht;Felice Crupi;Dominique Schreurs","doi":"10.1109/JERM.2023.3278473","DOIUrl":"10.1109/JERM.2023.3278473","url":null,"abstract":"Fall incidents represent a major public health problem among elderly people. This resulted in a significant increase of the number of investigated systems aiming at detecting falls promptly. In this respect, in this work, a biomedical radar system is proposed for remote real-time fall detection and indoor localization. The system, consisting of a sensor and a base station, combines radar and wireless communication techniques, and uses a data processing technique to distinguish between fall events and normal movements. The classification, based on a Least-Square Support Vector Machine (LS -SVM), combined with the sliding window principle allows to perform fall detection in real-time. Moreover, it is capable to localize the subjects when the fall incident has been detected. The in-vivo validation showed a high success rate in detecting fall events, with a maximum delay of 340 ms. Moreover, a maximum mean absolute errors (MAE) of 3.8 cm and a maximum root-mean-square error (RMSE) of 7.5 cm were reported in measuring the subject's absolute distance.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 4","pages":"303-312"},"PeriodicalIF":3.2,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86969732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-23DOI: 10.1109/JERM.2023.3257480
Aleksandar Savić;Fabian Freiberger;Ralf Pörtner;Arne F. Jacob
The article deals with broadband microwave measurements performed on single dead and living biological cells from CHO and HepG2 cell lines. It reports results obtained with coplanar waveguide reflection and transmission type sensors, respectively. A straight-forward single liquid calibration procedure allows to extract the complex cell permittivity and compare it to that of the surrounding medium. The contrast is analyzed through $p$ -value tests and in terms of the usual Cole-Cole parameters. The results demonstrate the distinguishability of the cell lines based on the permittivity.
{"title":"CHO and HepG2 Single-Cell Characterization With Planar Microchip Sensors up to 40 GHz","authors":"Aleksandar Savić;Fabian Freiberger;Ralf Pörtner;Arne F. Jacob","doi":"10.1109/JERM.2023.3257480","DOIUrl":"https://doi.org/10.1109/JERM.2023.3257480","url":null,"abstract":"The article deals with broadband microwave measurements performed on single dead and living biological cells from CHO and HepG2 cell lines. It reports results obtained with coplanar waveguide reflection and transmission type sensors, respectively. A straight-forward single liquid calibration procedure allows to extract the complex cell permittivity and compare it to that of the surrounding medium. The contrast is analyzed through \u0000<inline-formula><tex-math>$p$</tex-math></inline-formula>\u0000-value tests and in terms of the usual Cole-Cole parameters. The results demonstrate the distinguishability of the cell lines based on the permittivity.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 3","pages":"236-244"},"PeriodicalIF":3.2,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50291931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-17DOI: 10.1109/JERM.2023.3274742
Wenjun Wang;Juan Diego Sánchez-Heredia;Tom Maurouard;Vitaliy Zhurbenko;Jan Henrik Ardenkjær-Larsen
Objective: Double-loop H-field probes are often used to measure current on loop antennae for magnetic resonance imaging (MRI). Loop crosstalk limits the dynamic range of direct measurements with such probes. The crosstalk can be removed by simple calibration. This work analyses the quantitative relation of a probe's calibrated ${S}_{21}$ with the RF coil current. Method: The analytical relation between RF coil current and calibrated ${S}_{21}$ measurements of a probe is established with the multi-port network theory, and verified by full-wave simulation and benchtop measurements. The effect of calibration is demonstrated by measuring the 1 H trap frequency, the active detuning, and the preamplifier decoupling. Results: The calibration removes the effect of crosstalk in a probe and improves the lower bound of $| {{S}_{21}} |$ . The calibrated ${S}_{21}$ is proportional to coil current. In the lower frequency range, the ratio of calibrated ${S}_{21}$ to coil current changes almost linearly with frequency. Impact : The calibration method improves the sensitivity of probe measurements and facilitates fine-tuning current-suppressing circuits like active detuning circuits, traps, preamplifier decoupling. The linear frequency dependency between ${S}_{21}$ measurements and coil current allows easy, fair comparison of coil current up to 128 MHz, and in some cases 298 MHz, helping build multi-nucleus coils.
{"title":"Calibrating Double-Loop H-Field Probe Measurements of RF Coil Current for MRI","authors":"Wenjun Wang;Juan Diego Sánchez-Heredia;Tom Maurouard;Vitaliy Zhurbenko;Jan Henrik Ardenkjær-Larsen","doi":"10.1109/JERM.2023.3274742","DOIUrl":"https://doi.org/10.1109/JERM.2023.3274742","url":null,"abstract":"<bold>Objective:</b>\u0000 Double-loop H-field probes are often used to measure current on loop antennae for magnetic resonance imaging (MRI). Loop crosstalk limits the dynamic range of direct measurements with such probes. The crosstalk can be removed by simple calibration. This work analyses the quantitative relation of a probe's calibrated \u0000<inline-formula><tex-math>${S}_{21}$</tex-math></inline-formula>\u0000 with the RF coil current. \u0000<bold>Method:</b>\u0000 The analytical relation between RF coil current and calibrated \u0000<inline-formula><tex-math>${S}_{21}$</tex-math></inline-formula>\u0000 measurements of a probe is established with the multi-port network theory, and verified by full-wave simulation and benchtop measurements. The effect of calibration is demonstrated by measuring the \u0000<sup>1</sup>\u0000H trap frequency, the active detuning, and the preamplifier decoupling. \u0000<bold>Results:</b>\u0000 The calibration removes the effect of crosstalk in a probe and improves the lower bound of \u0000<inline-formula><tex-math>$| {{S}_{21}} |$</tex-math></inline-formula>\u0000. The calibrated \u0000<inline-formula><tex-math>${S}_{21}$</tex-math></inline-formula>\u0000 is proportional to coil current. In the lower frequency range, the ratio of calibrated \u0000<inline-formula><tex-math>${S}_{21}$</tex-math></inline-formula>\u0000 to coil current changes almost linearly with frequency. \u0000<bold>Impact</b>\u0000: The calibration method improves the sensitivity of probe measurements and facilitates fine-tuning current-suppressing circuits like active detuning circuits, traps, preamplifier decoupling. The linear frequency dependency between \u0000<inline-formula><tex-math>${S}_{21}$</tex-math></inline-formula>\u0000 measurements and coil current allows easy, fair comparison of coil current up to 128 MHz, and in some cases 298 MHz, helping build multi-nucleus coils.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 3","pages":"266-272"},"PeriodicalIF":3.2,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50291933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wearable assistive devices are essential for performance monitoring and inferring the tongue gestures of disabled individuals in medical rehabilitation. In this paper, a flexible and wearable differential extraoral antenna is proposed with dual resonances (915 MHz and 2.4 GHz) in the Industrial, Scientific, and Medical (ISM) band for extraoral tongue drive system (eTDS) applications. The size of the fabricated prototype of the extraoral differential antenna is (0.135 ${{bm{lambda }}}_{bm{g}} , times, $ 0.065 ${{bm{lambda }}}_{bm{g}} , times , $ 0.002 ${{bm{lambda }}}_{bm{g}}$ ). The performance of the differential extraoral antenna is analysed using a realistic human head model. Further, the extraoral antenna is fabricated and experimentally validated its performance in the close vicinity of the artificial head model. The measured impedance bandwidth (≤ −10 dB) and peak gain values are 90 MHz and $ -$ 20.00 dBi, respectively, at 0.915 GHz; and 180 MHz and $ -!$ 12.87 dBi, respectively, at 2.4 GHz. The specific absorption rate (SAR) parameter values have also been analyzed for both the resonating frequencies over 1 g and 10 g of mass tissue through simulations. Further, the link budget was theoretically calculated based on these acceptable SAR values. The proposed antenna could communicate effectively by eliminating balun's additional impedance mismatch loss due to direct interfacing. Thus, the proposed extraoral differential antenna can establish an effective communication link for data and power transfer in the eTDS technology-based applications.
{"title":"Flexible and Wearable Dual-Band Differential Extraoral Antenna for eTDS Applications","authors":"Sarita Ahlawat;Binod Kumar Kanaujia;Karumudi Rambabu","doi":"10.1109/JERM.2023.3271459","DOIUrl":"https://doi.org/10.1109/JERM.2023.3271459","url":null,"abstract":"Wearable assistive devices are essential for performance monitoring and inferring the tongue gestures of disabled individuals in medical rehabilitation. In this paper, a flexible and wearable differential extraoral antenna is proposed with dual resonances (915 MHz and 2.4 GHz) in the Industrial, Scientific, and Medical (ISM) band for extraoral tongue drive system (eTDS) applications. The size of the fabricated prototype of the extraoral differential antenna is (0.135\u0000<inline-formula><tex-math>${{bm{lambda }}}_{bm{g}} , times, $</tex-math></inline-formula>\u00000.065\u0000<inline-formula><tex-math>${{bm{lambda }}}_{bm{g}} , times , $</tex-math></inline-formula>\u00000.002\u0000<inline-formula><tex-math>${{bm{lambda }}}_{bm{g}}$</tex-math></inline-formula>\u0000). The performance of the differential extraoral antenna is analysed using a realistic human head model. Further, the extraoral antenna is fabricated and experimentally validated its performance in the close vicinity of the artificial head model. The measured impedance bandwidth (≤ −10 dB) and peak gain values are 90 MHz and \u0000<inline-formula><tex-math>$ -$</tex-math></inline-formula>\u000020.00 dBi, respectively, at 0.915 GHz; and 180 MHz and \u0000<inline-formula><tex-math>$ -!$</tex-math></inline-formula>\u0000 12.87 dBi, respectively, at 2.4 GHz. The specific absorption rate (SAR) parameter values have also been analyzed for both the resonating frequencies over 1 g and 10 g of mass tissue through simulations. Further, the link budget was theoretically calculated based on these acceptable SAR values. The proposed antenna could communicate effectively by eliminating balun's additional impedance mismatch loss due to direct interfacing. Thus, the proposed extraoral differential antenna can establish an effective communication link for data and power transfer in the eTDS technology-based applications.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 3","pages":"229-235"},"PeriodicalIF":3.2,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50404734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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