Journal of Electrical Bioimpedance最新文献

{"title":"Low Error Kramers-Kronig Estimations Using Symmetric Extrapolation Method.","authors":"G A Ruiz,&nbsp;C J Felice","doi":"10.2478/joeb-2021-0017","DOIUrl":"https://doi.org/10.2478/joeb-2021-0017","url":null,"abstract":"<p><p>Kramers-Kronig (KK) equations allow us to obtain the real or imaginary part of linear, causal and time constant functions, starting from the imaginary or real part respectively. They are normally applied on different practical applications as a control method. A common problem in measurements is the lack of data in a wide-range frequency, due to some of the inherent limitations of experiments or practical limitations of the used technology. Different solutions to this problem were proved, such as several methods for extrapolation, some of which based on piecewise polynomial fit or the approach based on the expected asymptotical behavior. In this work, we propose an approach based on the symmetric extrapolation method to generate data in missing frequency ranges, to minimize the estimated error of the KK equations. The results show that with data from impedance measurements of an electrode-electrolyte interface, the adjustment error of the transformed functions can be drastically reduced to below 1%.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"147-152"},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8713384/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39729221","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}

{"title":"Cervical Cancer Prognosis and Diagnosis Using Electrical Impedance Spectroscopy.","authors":"Ping Li,&nbsp;Peter E Highfield,&nbsp;Zi-Qiang Lang,&nbsp;Darren Kell","doi":"10.2478/joeb-2021-0018","DOIUrl":"10.2478/joeb-2021-0018","url":null,"abstract":"<p><p>Electrical impedance spectroscopy (EIS) has been used as an adjunct to colposcopy for cervical cancer diagnosis for many years, Currently, the template match method is employed for EIS measurements analysis, where the measured EIS spectra are compared with the templates generated from three-dimensional finite element (FE) models of cancerous and non-cancerous cervical tissue, and the matches between the measured EIS spectra and the templates are then used to derive a score that indicates the association strength of the measured EIS to the High-Grade Cervical Intraepithelial Neoplasia (HG CIN). These FE models can be viewed as the computational versions of the associated physical tissue models. In this paper, the problem is revisited with an objective to develop a new method for EIS data analysis that might reveal the relationship between the change in the tissue structure due to disease and the change in the measured spectrum. This could provide us with important information to understand the histopathological mechanism that underpins the EIS-based HG CIN diagnostic decision making and the prognostic value of EIS for cervical cancer diagnosis. A further objective is to develop an alternative EIS data processing method for HG CIN detection that does not rely on physical models of tissues so as to facilitate extending the EIS technique to new medical diagnostic applications where the template spectra are not available. An EIS data-driven method was developed in this paper to achieve the above objectives, where the EIS data analysis for cervical cancer diagnosis and prognosis were formulated as the classification problems and a Cole model-based spectrum curve fitting approach was proposed to extract features from EIS readings for classification. Machine learning techniques were then used to build classification models with the selected features for cervical cancer diagnosis and evaluation of the prognostic value of the measured EIS. The interpretable classification models were developed with real EIS data sets, which enable us to associate the changes in the observed EIS and the risk of being HG CIN or developing HG CIN with the changes in tissue structure due to disease. The developed classification models were used for HG CIN detection and evaluation of the prognostic value of EIS and the results demonstrated the effectiveness of the developed method. The method developed is of long-term benefit for EIS-based cervical cancer diagnosis and, in conjunction with standard colposcopy, there is the potential for the developed method to provide a more effective and efficient patient management strategy for clinic practice.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"153-162"},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8713385/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39729222","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}

{"title":"Bandwidth and Common Mode Optimization for Current and Voltage Sources in Bioimpedance Spectroscopy.","authors":"Tobias Menden,&nbsp;Jascha Matuszczyk,&nbsp;Steffen Leonhardt,&nbsp;Marian Walter","doi":"10.2478/joeb-2021-0016","DOIUrl":"https://doi.org/10.2478/joeb-2021-0016","url":null,"abstract":"<p><p>Bioimpedance measurements use current or voltage sources to inject an excitation signal into the body. These sources require a high bandwidth, typically from 1 kHz to 1 MHz. Besides a low common mode, current limitation is necessary for patient safety. In this paper, we compare a symmetric enhanced Howland current source (EHCS) and a symmetric voltage source (VS) based on a non-inverting amplifier between 1 kHz and 1 MHz. A common mode reduction circuit has been implemented in both sources. The bandwidth of each source was optimized in simulations and achieved a stable output impedance over the whole frequency range. In laboratory measurements, the output impedance of the EHCS had its -3 dB point at 400 kHz. In contrast, the VS reached the +3 dB point at 600 kHz. On average over the observed frequency range, the active common mode compensation achieved a common mode rejection of -57.7 dB and -71.8 dB for the EHCS and VS, respectively. Our modifications to classical EHCS and VS circuits achieved a low common mode signal between 1 kHz and 1 MHz without the addition of complex circuitry, like general impedance converters. As a conclusion we found VSs to be superior to EHCSs for bioimpedance spectroscopy due to the higher bandwidth performance. However, this only applies if the injected current of the VS can be measured.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"135-146"},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8713387/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39729220","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}

{"title":"Estimation of Heart Rate Variability from Finger Photoplethysmography During Rest, Mild Exercise and Mild Mental Stress.","authors":"Bjørn-Jostein Singstad,&nbsp;Naomi Azulay,&nbsp;Andreas Bjurstedt,&nbsp;Simen S Bjørndal,&nbsp;Magnus F Drageseth,&nbsp;Peter Engeset,&nbsp;Kari Eriksen,&nbsp;Muluberhan Y Gidey,&nbsp;Espen O Granum,&nbsp;Matias G Greaker,&nbsp;Amund Grorud,&nbsp;Sebastian O Hewes,&nbsp;Jie Hou,&nbsp;Adrián M Llop Recha,&nbsp;Christoffer Matre,&nbsp;Arnoldas Seputis,&nbsp;Simen E Sørensen,&nbsp;Vegard Thøgersen,&nbsp;Vegard Munkeby Joten,&nbsp;Christian Tronstad,&nbsp;Ørjan G Martinsen","doi":"10.2478/joeb-2021-0012","DOIUrl":"https://doi.org/10.2478/joeb-2021-0012","url":null,"abstract":"<p><p>Due to the possibilities in miniaturization and wearability, photoplethysmography (PPG) has recently gained a large interest not only for heart rate measurement, but also for estimating heart rate variability, which is derived from ECG by convention. The agreement between PPG and ECG-based HRV has been assessed in several studies, but the feasibility of PPG-based HRV estimation is still largely unknown for many conditions. In this study, we assess the feasibility of HRV estimation based on finger PPG during rest, mild physical exercise and mild mental stress. In addition, we compare different variants of signal processing methods including selection of fiducial point and outlier correction. Based on five minutes synchronous recordings of PPG and ECG from 15 healthy participants during each of these three conditions, the PPG-based HRV estimation was assessed for the SDNN and RMSSD parameters, calculated based on two different fiducial points (foot point and maximum slope), with and without outlier correction. The results show that HRV estimation based on finger PPG is feasible during rest and mild mental stress, but can give large errors during mild physical exercise. A good estimation is very dependent on outlier correction and fiducial point selection, and SDNN seems to be a more robust parameter compared to RMSSD for PPG-based HRV estimation.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"89-102"},"PeriodicalIF":0.0,"publicationDate":"2021-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8713388/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39714421","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}

{"title":"Storing Information Electrically in Human Skin.","authors":"Oliver Pabst,&nbsp;Øystein Magnus Sørebø,&nbsp;Karoline Sjøen Andersen,&nbsp;Erlend Lemva Ousdal,&nbsp;Sean William Bråthen,&nbsp;Badi Ur Rehman,&nbsp;Haiatullah Gholami,&nbsp;Zhijian Zhou,&nbsp;Koki Takahashi,&nbsp;Diriba Tasfaye Dumesso,&nbsp;Mellie Merete Livingston,&nbsp;Wesley Julian Lodewijk,&nbsp;Stian Sæther,&nbsp;Alireza Eskandari Turk,&nbsp;Peter Louis Uller","doi":"10.2478/joeb-2021-0010","DOIUrl":"https://doi.org/10.2478/joeb-2021-0010","url":null,"abstract":"<p><p>Human skin has been classified as a non-volatile memristor and it is shown that information can be stored within for at least three minutes. Here we investigate whether it is possible to store information up to 20 minutes. Furthermore, we investigate whether the information can be based on four different states, not just two (binary). We stored the information into the skin of the forehead of the test subjects under three different electrodes, which allows in principle for 64 different combinations (3 electrodes, 4 states) and one can think of numbers on the base of four. For this experiment, we decided on the numbers 123₄ and 302₄ (that correspond to numbers 27 and 50 in the decimal system). Writing of the different states was done by the application of DC voltage pulses that cause electro-osmosis in the sweat ducts (nonlinear electrical measurements). Based on our results, we were not able to distinguish between four different states. However, we can show that binary information storage in human skin is possible for up to 20 minutes.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"73-81"},"PeriodicalIF":0.0,"publicationDate":"2021-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667810/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39714420","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}

{"title":"Assessing Ischemic Injury in Human Intestine Ex Vivo with Electrical Impedance Spectroscopy.","authors":"Jie Hou,&nbsp;Runar Strand-Amundsen,&nbsp;Stina Hødnebø,&nbsp;Tor Inge Tønnessen,&nbsp;Jan Olav Høgetveit","doi":"10.2478/joeb-2021-0011","DOIUrl":"https://doi.org/10.2478/joeb-2021-0011","url":null,"abstract":"<p><p>Electrical impedance spectroscopy is a well-established tool for monitoring changes in the electrical properties of tissue. Most tissue and organ types have been investigated in various studies. As for the small intestine, there are several published studies conducted on pig and rat models. This study investigates the changes in passive electrical properties of the complete wall of the human intestine non-invasively during ischemia. We aim to use the passive electrical properties to assess intestinal viability. The bioimpedance measurements were performed using a two-electrode set-up with a Solartron 1260 Impedance/gain-phase analyser. The small intestinal samples were resected from patients who underwent pancreaticoduodenectomy. Impedance measurements were conducted following resection by placing the electrodes on the surface of the intestine. A voltage was applied across the intestinal sample and the measured electrical impedance was obtained in the ZPlot software. Impedance data were further fitted into a Cole model to obtain the Cole parameters. The <i>P_y</i> value was calculated from the extracted Cole parameters and used to assess the cell membrane integrity, thus evaluate the intestinal viability. Eight small intestinal segments from different patients were used in this study and impedance measurements were performed once an hour for a ten-hour period. One hour after resection, the impedance decreased, then increased the next two hours, before decreasing until the end of the experiment. For all the intestinal segments, the <i>P_y</i> values first increased and reached a plateau which lasted for 1 - 2 hours, before it decreased irreversibly. The time interval where <i>P_y</i> value reached the maximum is consistent with reported viable/non-viable limits from histological analysis.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"82-88"},"PeriodicalIF":0.0,"publicationDate":"2021-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667813/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39771376","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}

{"title":"Impedance-based Real-time Monitoring of Neural Stem Cell Differentiation.","authors":"F J Shah,&nbsp;C Caviglia,&nbsp;K Zór,&nbsp;M Carminati,&nbsp;G Ferrari,&nbsp;M Sampietro,&nbsp;A Martínez-Serrano,&nbsp;J K Emnéus,&nbsp;A R Heiskanen","doi":"10.2478/joeb-2021-0006","DOIUrl":"https://doi.org/10.2478/joeb-2021-0006","url":null,"abstract":"<p><p>We present here the first impedance-based characterization of the differentiation process of two human mesencephalic fetal neural stem lines. The two dopaminergic neural stem cell lines used in this study, Lund human mesencephalic (LUHMES) and human ventral mesencephalic (hVM1 Bcl-X_L), have been developed for the study of Parkinsonian pathogenesis and its treatment using cell replacement therapy. We show that if only relying on impedance magnitude analysis, which is by far the most usual approach in, e.g., cytotoxicity evaluation and drug screening applications, one may not be able to distinguish whether the neural stem cells in a population are proliferating or differentiating. However, the presented results highlight that equivalent circuit analysis can provide detailed information on cellular behavior, e.g. simultaneous changes in cell morphology, cell-cell contacts, and cell adhesion during formation of neural projections, which are the fundamental behavioral differences between proliferating and differentiating neural stem cells. Moreover, our work also demonstrates the sensitivity of impedance-based monitoring with capability to provide information on changes in cellular behavior in relation to proliferation and differentiation. For both of the studied cell lines, in already two days (one day after induction of differentiation) equivalent circuit analysis was able to show distinction between proliferation and differentiation conditions, which is significantly earlier than by microscopic imaging. This study demonstrates the potential of impedance-based monitoring as a technique of choice in the study of stem cell behavior, laying the foundation for screening assays to characterize stem cell lines and testing the efficacy epigenetic control.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"34-49"},"PeriodicalIF":0.0,"publicationDate":"2021-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667812/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39860497","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}

{"title":"Comparison of Electrical Impedance Tomography and Ultrasonography for Determination of Solid and Cystic Lesion Resembling Breast Tumor Embedded in Chicken Phantom.","authors":"L Choridah,&nbsp;D Kurniadi,&nbsp;K Ain,&nbsp;M F Ulum,&nbsp;U Mukhaiyar,&nbsp;A D Garnadi,&nbsp;N H Setyawan","doi":"10.2478/joeb-2021-0008","DOIUrl":"https://doi.org/10.2478/joeb-2021-0008","url":null,"abstract":"<p><p>Ultrasonography (US) and Electrical Impedance Tomography (EIT) can be used to detect breast cancer. Ultrasonography is based on non-ionizing radiations without adverse biological effects. A set of electrodes was placed around the torso and a small alternating current (AC) was injected via two of the electrodes into the object. This study aimed to acquire preliminary data to evaluate the EIT method for differentiation of artificial solid and cystic tumors in comparison to standard US. This study used a phantom made from chicken meat. In order to obtain the image of the solid tumor, an olive with carrot insertion was done, and the cystic tumor was created by filling a small balloon with water. GE Logic C5 ultrasound was performed with a 12 MHz linear transducer. For EIT measurement, 16 ECG electrodes and 32 ECG electrodes were placed. Data processing was done using the Graz consensus Reconstruction algorithm for EIT (GREIT) and Newton's One Step Error Reconstructor (NOSER) methods. The artificial solid tumor produced an ultrasound image of an oval, inhomogeneous lesions. The GREIT method with 16 electrodes of artificial solid tumor did not show a match between the reconstructed image and the original object containing 2 anomalies, but a match was found with 32 electrodes. In the NOSER method, both 16 and 32 electrodes showed a match. Ultrasound of the artificial cystic tumor showed an oval, circumscribed, anechoic with posterior enhancement. Both the GREIT and NOSER methods using the artificial cystic tumor showed a match between the reconstructed image and the original object containing two anomalies. EIT has a lower imaging resolution in comparison to ultrasonography, but is progressively maturing as a tool for monitoring and imaging. The solid and cystic anomalies on the phantoms were visualized by the GREIT and NOSER methods except for the solid anomaly with the GREIT 16 electrodes.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"63-68"},"PeriodicalIF":0.0,"publicationDate":"2021-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667814/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39860498","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}

{"title":"Bioimpedance to Assess the Body Composition of High-performance Karate Athletes: Applications, Advantages and Perspectives.","authors":"Luciana Rossi","doi":"10.2478/joeb-2021-0009","DOIUrl":"https://doi.org/10.2478/joeb-2021-0009","url":null,"abstract":"<p><p>Karate, a millennial martial art, was recently inserted among traditional Olympic combat sports for the Olympic Games in Japan. The aim of the present study is to determine, through bioimpedance analysis, the body composition of high-performance athletes participating in the São Paulo Olympic Karate Project. Participants were 22 athletes of both sexes, average age of 23.6 (6.0) years old, body mass of 66.6 (13.5) kg and fat percentage of 16.6 (5.5)%. Bioimpedance test indicated significant differences between sexes related to sexual dysmorphia, which had an impact on bioelectrical variables. Through comparative evaluation between male and female athletes, this study contributes to body composition analysis, indicating that, in the future, related bioimpedance tests should be used beyond their classical application, including phase angle, muscle function and other attributes.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"69-72"},"PeriodicalIF":0.0,"publicationDate":"2021-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667809/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39714419","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}

{"title":"Electrical Impedance Tomography - Recent Applications and Developments.","authors":"Sofiene Mansouri,&nbsp;Yousef Alharbi,&nbsp;Fatma Haddad,&nbsp;Souhir Chabcoub,&nbsp;Anwar Alshrouf,&nbsp;Amr A Abd-Elghany","doi":"10.2478/joeb-2021-0007","DOIUrl":"https://doi.org/10.2478/joeb-2021-0007","url":null,"abstract":"<p><p>Electrical impedance tomography (EIT) is a low-cost noninvasive imaging method. The main purpose of this paper is to highlight the main aspects of the EIT method and to review the recent advances and developments. The advances in instrumentation and in the different image reconstruction methods and systems are demonstrated in this review. The main applications of the EIT are presented and a special attention made to the papers published during the last years (from 2015 until 2020). The advantages and limitations of EIT are also presented. In conclusion, EIT is a promising imaging approach with a strong potential that has a large margin of progression before reaching the maturity phase.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"12 1","pages":"50-62"},"PeriodicalIF":0.0,"publicationDate":"2021-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8667811/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39714418","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}