Pub Date : 2023-07-03DOI: 10.1109/JERM.2023.3285049
Jacob T. Pawlik;Nikolas D. Barrera;Eugene J. Yoon;James C. Booth;Christian J. Long;Nathan D. Orloff;Ellis Meng;Angela C. Stelson
Parylene C is a widely used dielectric barrier in implantable medical devices because it conforms well to surfaces and insulates against biological environments. However, multiple studies have shown that moisture can intrude into Parylene C films through defects and intrinsic diffusion, leading to delamination and device failure. While many studies have tested device integrity in vitro, few have isolated the influence of specific degradation mechanisms on device failure. Here, we use a broadband impedance technique called Microwave Microfluidic Spectroscopy (MMS) to measure fluid permeation in targeted regions of Parylene C films that are free of defects and have optimal adhesion to the substrate. We found no changes in the broadband S-parameters from 100 MHz–110 GHz for Parylene C coated coplanar waveguides soaked in water or phosphate buffered saline at 20 °C or 37 °C for two months. Furthermore, there was no delamination induced by fluid soaking. Our study helps to clear debate about the influence of water and ion diffusion on Parylene C device lifetime and inform better fabrication of Parylene C coatings for implantable devices.
{"title":"The Influence of Intrinsic Water and Ion Permeation on the Dielectric Properties of Parylene C Films","authors":"Jacob T. Pawlik;Nikolas D. Barrera;Eugene J. Yoon;James C. Booth;Christian J. Long;Nathan D. Orloff;Ellis Meng;Angela C. Stelson","doi":"10.1109/JERM.2023.3285049","DOIUrl":"10.1109/JERM.2023.3285049","url":null,"abstract":"Parylene C is a widely used dielectric barrier in implantable medical devices because it conforms well to surfaces and insulates against biological environments. However, multiple studies have shown that moisture can intrude into Parylene C films through defects and intrinsic diffusion, leading to delamination and device failure. While many studies have tested device integrity in vitro, few have isolated the influence of specific degradation mechanisms on device failure. Here, we use a broadband impedance technique called Microwave Microfluidic Spectroscopy (MMS) to measure fluid permeation in targeted regions of Parylene C films that are free of defects and have optimal adhesion to the substrate. We found no changes in the broadband S-parameters from 100 MHz–110 GHz for Parylene C coated coplanar waveguides soaked in water or phosphate buffered saline at 20 °C or 37 °C for two months. Furthermore, there was no delamination induced by fluid soaking. Our study helps to clear debate about the influence of water and ion diffusion on Parylene C device lifetime and inform better fabrication of Parylene C coatings for implantable devices.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 4","pages":"328-335"},"PeriodicalIF":3.2,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72592318","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 : 2023-06-30DOI: 10.1109/JERM.2023.3289155
Peter M. Asbeck;Sravya Alluri;Vincent Leung;Shaghayegh Abbasi;Milan T. Makale
Pulse stimulation of peripheral nerves (PNS) is extensively used in the diagnosis of nerve abnormalities and can be applied for pain mitigation and to promote nerve regrowth. Nerve stimulation via magnetic pulses can provide advantages over conventional electrical stimulation; it obviates the need for electrode contact with the skin and is typically less painful. This work contributes to the development of compact and portable systems for magnetic PNS (M-PNS). To date, M-PNS has largely employed pulse generation systems developed for repetitive transcranial magnetic stimulation (rTMS). A new circuit is demonstrated to generate pulsed magnetic fields that increases induced electric (E) field intensities over those attainable in conventional rTMS systems. The resultant E-field has a shortened duration. The required external voltage input is below 300 V. A compact circuit implementation produced peak E-fields of 280 V/m at 1.5 cm distance from the magnetic coil, in 23 μs pulses (while 70-280 μs pulses are typically used for rTMS). Although threshold E fields for neural excitation increase with shorter pulse widths, neural excitation is demonstrated in human subjects via ulnar nerve stimulation and electromyography. This circuit technique may facilitate greater feasibility and flexibility in the design of miniaturized and portable PNS medical devices.
{"title":"An Efficient Circuit for Pulsed Magnetic Neural Stimulation","authors":"Peter M. Asbeck;Sravya Alluri;Vincent Leung;Shaghayegh Abbasi;Milan T. Makale","doi":"10.1109/JERM.2023.3289155","DOIUrl":"https://doi.org/10.1109/JERM.2023.3289155","url":null,"abstract":"Pulse stimulation of peripheral nerves (PNS) is extensively used in the diagnosis of nerve abnormalities and can be applied for pain mitigation and to promote nerve regrowth. Nerve stimulation via magnetic pulses can provide advantages over conventional electrical stimulation; it obviates the need for electrode contact with the skin and is typically less painful. This work contributes to the development of compact and portable systems for magnetic PNS (M-PNS). To date, M-PNS has largely employed pulse generation systems developed for repetitive transcranial magnetic stimulation (rTMS). A new circuit is demonstrated to generate pulsed magnetic fields that increases induced electric (E) field intensities over those attainable in conventional rTMS systems. The resultant E-field has a shortened duration. The required external voltage input is below 300 V. A compact circuit implementation produced peak E-fields of 280 V/m at 1.5 cm distance from the magnetic coil, in 23 μs pulses (while 70-280 μs pulses are typically used for rTMS). Although threshold E fields for neural excitation increase with shorter pulse widths, neural excitation is demonstrated in human subjects via ulnar nerve stimulation and electromyography. This circuit technique may facilitate greater feasibility and flexibility in the design of miniaturized and portable PNS medical devices.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 3","pages":"258-265"},"PeriodicalIF":3.2,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50404732","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}
In recent years, cerebrovascular disease has become one of the leading causes of death among Chinese residents. Early detection of brain disease is, therefore, of great significance in reducing the risks to life and health. Thermoacoustic imaging has emerged as a promising technique for detecting brain disease, which meets the requirements of high penetration depth and real-time imaging in transcranial imaging. However, the acoustic characteristics of the skull can significantly impact the propagation of thermoacoustic signals, leading to attenuation and apparent phase difference, resulting in poor quality of reconstructed image and location deviation of symptom points. In this study, a skull phase compensated method combined full waveform inversion for transcranial thermoacoustic imaging is proposed. The adaptive positioning of skull is realized firstly by improving the W-AIC algorithm in thermoacoustic imaging to solve the phase difference problem and FWI technology is applied for reconstructing the intracranial SoS distribution. Numerical simulation of a human brain model and actual human skull experiments further verify the feasibility of this method in improving the quality of thermoacoustic images, thereby providing a reliable theoretical basis for the clinical application of transcranial thermoacoustic imaging.
{"title":"Skull Phase Compensation Combined Full Waveform Inversion for Transcranial Thermoacoustic Imaging With a Real Human Skull Validated","authors":"Shuang-Li Liu;Xin Shang;Wan-Ting Peng;Wei-Jia Wan;Jin-Bao Zhang","doi":"10.1109/JERM.2023.3281057","DOIUrl":"10.1109/JERM.2023.3281057","url":null,"abstract":"In recent years, cerebrovascular disease has become one of the leading causes of death among Chinese residents. Early detection of brain disease is, therefore, of great significance in reducing the risks to life and health. Thermoacoustic imaging has emerged as a promising technique for detecting brain disease, which meets the requirements of high penetration depth and real-time imaging in transcranial imaging. However, the acoustic characteristics of the skull can significantly impact the propagation of thermoacoustic signals, leading to attenuation and apparent phase difference, resulting in poor quality of reconstructed image and location deviation of symptom points. In this study, a skull phase compensated method combined full waveform inversion for transcranial thermoacoustic imaging is proposed. The adaptive positioning of skull is realized firstly by improving the W-AIC algorithm in thermoacoustic imaging to solve the phase difference problem and FWI technology is applied for reconstructing the intracranial SoS distribution. Numerical simulation of a human brain model and actual human skull experiments further verify the feasibility of this method in improving the quality of thermoacoustic images, thereby providing a reliable theoretical basis for the clinical application of transcranial thermoacoustic imaging.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 4","pages":"313-319"},"PeriodicalIF":3.2,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75290361","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 : 2023-06-07DOI: 10.1109/JERM.2023.3281726
Sen Bing;Khengdauliu Chawang;J.-C. Chiao
In this work, a planar microwave sensor based on a flexible polyimide substrate has been developed to distinguish if a skin lesion is malignant or benign. The sensor is a tuned loop resonator operating in the industrial, scientific, and medical (ISM) band at 2.465 GHz, providing a localized high-intensity electric field that penetrates into tissues with sufficient spatial and spectral resolutions. The loop resonator with a radius of 5.4 mm was tuned by a concentric metal pad to the desired resonant frequency with a sufficiently high quality factor of 98.7 and a reflection coefficient of $-$ 63.98 dB. The sensor is based on the detection of electromagnetic resonance change and sequential frequency shift that is susceptible to the dielectric property difference between cancerous and benign tissues. Basal Cell Carcinoma (BCC) and Seborrheic Keratosis (SK), the most commonly found malignant and benign skin lesions with close visual similarities, were selected to demonstrate the sensing concept. Tissue-mimicking materials were fabricated to have similar dielectric properties to those of healthy skin, SK, and BCC tissues in the literature. Simulations and measurements were conducted. Significant frequency shifts of 759 MHz and 415 MHz were observed between BCC and SK phantoms in simulations and measurements, respectively, when the size of the tumor phantom was a cuboid of 12 mm × 12 mm × 4 mm underneath and among healthy skin. Simulations were conducted for different cuboid side lengths from 2 to 16 mm while the thickness remained at 4 mm. Malignant lesions could be distinguished with a cuboid side length as small as 2 mm. Corresponding measurements for cuboid side lengths of 6, 8, 10, and 12 mm were conducted and matched the trend well with the simulation results. The promising results in simulations and measurements validate the sensing principle, showing great potential for skin cancer detection in a noninvasive, efficient, and lower-cost way.
在这项工作中，基于柔性聚酰亚胺衬底的平面微波传感器已经开发出来，以区分皮肤病变是恶性还是良性。该传感器是一个调谐环路谐振器，工作在2.465 GHz的工业、科学和医疗(ISM)频段，提供局部高强度电场，穿透组织，具有足够的空间和光谱分辨率。环形谐振器的半径为5.4 mm，通过同心金属衬垫调谐到所需的谐振频率，质量因子为98.7，反射系数为$-$63.98 dB。该传感器是基于检测易受癌组织和良性组织介电特性差异影响的电磁共振变化和顺序频移。基底细胞癌(BCC)和脂溢性角化病(SK)是最常见的恶性和良性皮肤病变，具有密切的视觉相似性，被选择来证明感知概念。在文献中，组织模拟材料被制造成具有与健康皮肤、SK和BCC组织相似的介电特性。进行了模拟和测量。在模拟和测量中，当肿瘤幻影在健康皮肤下为12 mm × 12 mm × 4 mm的长方体时，在BCC和SK幻影之间分别观察到759 MHz和415 MHz的显著频移。在厚度保持在4 mm的情况下，对2 ~ 16 mm的不同长方体边长进行了模拟。恶性病变可以通过长至2mm的长方体边长来区分。对长方体边长6、8、10和12 mm进行了相应的测量，结果与仿真结果吻合较好。仿真和测量结果验证了传感原理，显示出以无创、高效和低成本的方式进行皮肤癌检测的巨大潜力。
{"title":"A Tuned Microwave Resonant Sensor for Skin Cancerous Tumor Diagnosis","authors":"Sen Bing;Khengdauliu Chawang;J.-C. Chiao","doi":"10.1109/JERM.2023.3281726","DOIUrl":"10.1109/JERM.2023.3281726","url":null,"abstract":"In this work, a planar microwave sensor based on a flexible polyimide substrate has been developed to distinguish if a skin lesion is malignant or benign. The sensor is a tuned loop resonator operating in the industrial, scientific, and medical (ISM) band at 2.465 GHz, providing a localized high-intensity electric field that penetrates into tissues with sufficient spatial and spectral resolutions. The loop resonator with a radius of 5.4 mm was tuned by a concentric metal pad to the desired resonant frequency with a sufficiently high quality factor of 98.7 and a reflection coefficient of \u0000<inline-formula><tex-math>$-$</tex-math></inline-formula>\u000063.98 dB. The sensor is based on the detection of electromagnetic resonance change and sequential frequency shift that is susceptible to the dielectric property difference between cancerous and benign tissues. Basal Cell Carcinoma (BCC) and Seborrheic Keratosis (SK), the most commonly found malignant and benign skin lesions with close visual similarities, were selected to demonstrate the sensing concept. Tissue-mimicking materials were fabricated to have similar dielectric properties to those of healthy skin, SK, and BCC tissues in the literature. Simulations and measurements were conducted. Significant frequency shifts of 759 MHz and 415 MHz were observed between BCC and SK phantoms in simulations and measurements, respectively, when the size of the tumor phantom was a cuboid of 12 mm × 12 mm × 4 mm underneath and among healthy skin. Simulations were conducted for different cuboid side lengths from 2 to 16 mm while the thickness remained at 4 mm. Malignant lesions could be distinguished with a cuboid side length as small as 2 mm. Corresponding measurements for cuboid side lengths of 6, 8, 10, and 12 mm were conducted and matched the trend well with the simulation results. The promising results in simulations and measurements validate the sensing principle, showing great potential for skin cancer detection in a noninvasive, efficient, and lower-cost way.","PeriodicalId":29955,"journal":{"name":"IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology","volume":"7 4","pages":"320-327"},"PeriodicalIF":3.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79343105","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 : 2023-04-27DOI: 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.
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