Daniel Voss, Clara Wemmer, Steffen Leonhardt, Marian Walter
{"title":"Time-variant left ventricle models for intracardiac impedance analysis.","authors":"Daniel Voss, Clara Wemmer, Steffen Leonhardt, Marian Walter","doi":"10.2478/joeb-2024-0015","DOIUrl":"10.2478/joeb-2024-0015","url":null,"abstract":"<p><p>Cardiovascular diseases are a leading cause of mortality worldwide. Thus, critically ill patients require continuous monitoring of cardiovascular indicators, such as the left ventricular volume (LVV). Although continuous hemodynamic monitoring of patients is desirable, due to technical limitations, current measurement technologies either require manual intervention of the physician or only provide inaccurate results. Intracardiac impedance measurements are a promising approach for continuous assessment of cardiac function. However, developing and evaluating these methods requires a simulation model of the left ventricle with cardiac motion during an entire cardiac cycle. While many models exist for a fixed ventricle size, to date, no freely available models incorporate time and represent the cardiac motion during a complete cardiac cycle. Therefore, we developed four cardiacmechanical left ventricular models with varying ventricle sizes and complexities. Each model focuses on a different aspect of the geometric shape, thus allowing an isolated analysis of the different influences. This paper presents the development of the models and initial results of the impedance analysis. All measured admittances exhibit a high resemblance for all models and a strong, non-linear correlation with the LVV. A comparison between the models shows how the different geometries affect the impedance. The models, thus, provide a useful basis for the development of LVV estimation algorithms.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"130-136"},"PeriodicalIF":0.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11452780/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381892","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}
Sisay Mebre Abie, Alejandro Ortega de Román, Jie Hou
{"title":"Effect of body orientation and joint movement on local bioimpedance measurements.","authors":"Sisay Mebre Abie, Alejandro Ortega de Román, Jie Hou","doi":"10.2478/joeb-2024-0016","DOIUrl":"10.2478/joeb-2024-0016","url":null,"abstract":"<p><p>The purpose of this pilot study was to determine if body orientation, skin treatment, joint angle, and shoulder arch movements affect localized bioimpedance spectroscopy (BIS) measurement. Nowadays, there are various wearable and portable impedance measurement tools in different shapes and sizes. Therefore, the body position and orientation of the subject during measurement may be of great importance for the comparability of the results. Ultrasound machine was used to measure the thickness of the skin layers and then bioimpedance measurements were performed for ten young men (age=23 ± 5) at room temperature (22°C) for different body orientations, skin treatments, joint angle, and shoulder arch movements. The results were analyzed using statistical methods and graphical presentation using Python and MatLab. Our observations indicate that there is a significant difference between standing straight up, supine and sitting positions. The results show that there is a significant difference between the two skin treatments (alcohol vs tape stripping). Moreover, joint angle and shoulder arch movements also have an impact on the impedance data. Therefore, to be able to control these factors can potentially improve the quality and comparability of the measured impedance data.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"137-144"},"PeriodicalIF":0.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11452779/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381890","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}
Safia Aktar Dipa, Muralee Monohara Pramanik, Mamun Rabbani, Muhammad Abdul Kadir
{"title":"Effects of temperature on electrical impedance of biological tissues: ex-vivo measurements.","authors":"Safia Aktar Dipa, Muralee Monohara Pramanik, Mamun Rabbani, Muhammad Abdul Kadir","doi":"10.2478/joeb-2024-0013","DOIUrl":"10.2478/joeb-2024-0013","url":null,"abstract":"<p><p>Bioelectrical impedance techniques have been useful in various applications, including body composition analysis, impedance plethysmography, impedance cardiography, lung ventilation, perfusion, and tissue characterization. Electrical impedance methods have also been useful in characterizing different foods like meat, fruits, and beverages. However, the temperature of tissue samples can change their dielectric properties, affecting their impedance. This research investigated the effects of temperature on the impedance of various biological tissues over the frequency range of 10 Hz to 5 MHz. Freshly excised animal tissues (lamb, cow, chicken), fish, fruits, and plants were considered as biological samples. The samples were placed in a test cell and submerged in a water bath heated by a hot plate to vary the temperature. Impedance measurements were conducted using a bioimpedance spectrometer in 2 °C steps within the temperature range of 20 °C to 50 °C. Impedance values decreased with increased temperature across all measurement frequencies for all biological samples. Curve fitting indicated that impedance decreased linearly with temperature, with a mean correlation coefficient of 0.972 for all samples. For all biological samples under investigation, the relative impedance change ranged from -0.58% to -2.27% per °C, with a mean and standard deviation of (-1.42±0.34) %/°C. On average, animal samples exhibited a higher relative temperature coefficient of -1.56% per °C (±0.41) across the frequency range, compared to -1.31% per °C (±0.26) for fruit and vegetable samples. Additionally, the relative temperature coefficient values were generally higher at lower frequencies than at higher frequencies. The findings of this research can be valuable for studies or biomedical applications involving variable tissue temperatures.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"116-124"},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11406437/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142297531","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":"Improving sensitivity in the deep regions of a volume conductor using electrical focused impedance methods.","authors":"Mahjabin Mobarak, K Siddique-E Rabbani","doi":"10.2478/joeb-2024-0012","DOIUrl":"https://doi.org/10.2478/joeb-2024-0012","url":null,"abstract":"<p><p>Bioimpedance measurements are becoming important in probing the human body for diagnosis and monitoring. An age old 4-electrode technique called tetrapolar impedance measurement (TPIM), giving transfer impedance, cannot localize a specific zone besides having large zones of negative sensitivity. A new technique named the focused impedance method (FIM) from Dhaka University (DU), Bangladesh used the algebraic average of two concentric and orthogonal TPIMs, localizing a zone of interest and having reduced magnitudes of negative sensitivity. Earlier, this was implemented with electrodes applied from one side of the human body giving information to shallow depths only. To get information from deeper regions, specifically, of the thorax, the same DU group placed two electrodes of a 4-electrode version of FIM at the front and two at the back in a horizontal plane of the thorax, using physics-based visualization. This was followed by a few quantitative studies using point sensitivity, which supported the concept. However, more quantitative studies still need to be performed, particularly using objects of finite sizes, in order to establish the technique on a stronger footing. The present study was taken up with this objective. A simplified approach was used in which the volume conductor was a rectangular non-conducting container filled with saline of uniform conductivity with an embedded spherical object - first an insulator and then a conductor. Electrodes were placed at specific chosen positions following the above visualization. Percentage change in transfer impedance with the object placed at different internal positions, compared to that without the object was obtained first using COMSOL simulation and then through experimental measurements. These were performed for both TPIM and FIM. The new configuration of 4-electrode FIM gave good depth sensitivity supporting the effectiveness of the new placement of electrodes.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"107-115"},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11381942/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142297532","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}
Galih Setyawan, Prima Asmara Sejati, Kiagus Aufa Ibrahim, Masahiro Takei
{"title":"Breast cancer recognition by electrical impedance tomography implemented with Gaussian relaxation-time distribution (EIT-GRTD).","authors":"Galih Setyawan, Prima Asmara Sejati, Kiagus Aufa Ibrahim, Masahiro Takei","doi":"10.2478/joeb-2024-0011","DOIUrl":"10.2478/joeb-2024-0011","url":null,"abstract":"<p><p>The comparison between breast cancer recognition by electrical impedance tomography implemented with Gaussian relaxation time distribution (EIT-GRTD) and conventional EIT has been conducted to evaluate the optimal frequency for cancer detection <i>f</i> <sup>cancer</sup>. The EIT-GRTD has two steps, which are 1) the determination of the <i>f</i> <sup>cancer</sup> and 2) the refinement of breast reconstruction through time-constant enhancement. This paper employs two-dimensional numerical simulations by a finite element method (FEM) software to replicate the process of breast cancer recognition. The simulation is constructed based on two distinct electrical properties, which are conductivity <i>σ</i> and permitivitty <i>ε</i>, inherent to two major breast tissues: adipose tissues, and breast cancer tissues. In this case, the <i>σ</i> and <i>ε</i> of breast cancer <i>σ</i> <sup>cancer</sup>, <i>ε</i> <sup>cancer</sup> are higher than adipose tissues <i>σ</i> <sup>adipose</sup>, <i>ε</i> <sup>adipose</sup>. The simulation results indicate that the most effective frequency for breast cancer detection based on EIT-GRTD is <i>f</i> <sup>cancer</sup> = 56,234 Hz. Meanwhile, conventional EIT requires more processing to determine the <i>f</i> <sup>cancer</sup> based on image results or spatial conductivity analysis. Quantitatively, both EIT-GRTD and conventional EIT can clearly show the position of the cancer in layers 1 and 2 for EIT-GRTD and only layer 1 for conventional EIT.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"99-106"},"PeriodicalIF":0.0,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11387985/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142297530","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}
Anabelle Vallecillo-Bustos, Abby T Compton, Sydney H Swafford, Megan E Renna, Tanner Thorsen, Jon Stavres, Austin J Graybeal
{"title":"The effect of postural orientation on body composition and total body water estimates produced by smartwatch bioelectrical impedance analysis: an intra- and inter-device evaluation.","authors":"Anabelle Vallecillo-Bustos, Abby T Compton, Sydney H Swafford, Megan E Renna, Tanner Thorsen, Jon Stavres, Austin J Graybeal","doi":"10.2478/joeb-2024-0010","DOIUrl":"10.2478/joeb-2024-0010","url":null,"abstract":"<p><p>Advances in wearable technologies now allow modern smartwatches to collect body composition estimates through bioelectrical impedance techniques embedded within their design. However, this technique is susceptible to increased measurement error when postural changes alter body fluid distribution. The purpose of this study was to evaluate the effects of postural orientation on body composition and total body water (TBW) estimates produced by smartwatch bioelectrical impedance analysis (SWBIA) and determine its agreement with criterion measures. For this cross-sectional evaluation, 117 (age: 21.4±3.0 y; BMI: 25.3±5.7 kg/m<sup>2</sup>) participants (F:69, M:48) completed SWBIA measurements while in the seated, standing, and supine positions, then underwent criterion dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance spectroscopy (BIS) assessments. In the combined sample and females, body fat percent, fat mass, and fat-free mass using SWBIA were significantly different between the supine and standing positions (all p<0.001), though group level agreement with DXA was similar across positions. Supine SWBIA TBW estimates were significantly different between seated and standing estimates (all p≤0.026), but further analyses revealed that this was driven by the supine and seated differences observed in females (p=0.003). SWBIA TBW demonstrated similar group and individual level agreement with BIS across body positions with slight improvements observed during seated and supine assessments for females and males, respectively. SWBIA may demonstrate slight intra- and inter-device differences in body composition and TBW when measured across postural orientations, though further evaluations in external/clinical samples are necessary. While sex/position-specific guidelines may improve precision, these findings highlight the importance of standardized body positioning when using SWBIA.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"89-98"},"PeriodicalIF":0.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11299788/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141894554","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":"Cell growth monitoring in a tetrapolar electrode configuration.","authors":"Jagbir Singh, Niranjan D Khambete","doi":"10.2478/joeb-2024-0009","DOIUrl":"10.2478/joeb-2024-0009","url":null,"abstract":"<p><p>There are various methods for cell growth monitoring. However, most of these methods have drawbacks, such as being invasive, not providing real-time results, or being costly. In this study, we present an alternate method of cell growth monitoring, which is low-cost, non-invasive, real-time, and uses Electrical Impedance Spectro-scopy (EIS). In this work, commercially available culture plates were fitted with custom tetrapolar electrodes, and mouse cells were cultured on them. The variation of culture media impedance, resulting from cell growth, proliferation and other metabolic activities, was recorded over a period of seven days. The results demonstrated an initial increase in impedance corresponding with the cell growth phase, followed by a decrease during the cell death (apoptosis) phase, as confirmed by microscope images. Overall, the results show that our method to monitor cell growth using tetrapolar electrodes is promising and can be further refined for related applications.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"85-88"},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11220369/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141500155","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}
Sisay Mebre Abie, Paweł Suliga, Bjørg Egelandsdal, Daniel Münch
{"title":"Bioimpedance as an alternative tool for subjective, visual scoring of a prevalent ham quality defect.","authors":"Sisay Mebre Abie, Paweł Suliga, Bjørg Egelandsdal, Daniel Münch","doi":"10.2478/joeb-2024-0008","DOIUrl":"10.2478/joeb-2024-0008","url":null,"abstract":"<p><p>The detection of meat quality defects can involve both subjective and objective methods. PSE-like meat is linked to a common pork defect and can be caused by rapid post-mortem damage of muscle fibers. This damage can again be linked to various factors, such as a low ultimate pH or a higher slaughter weight. PSE-like defects are characterized by discoloration, structural damage, and excessive moisture loss. However, the lack of suitable instrument-based methods makes the detection of PSE-like defects difficult, and subjective methods typically suffer from poorer reproducibility. The objective of this study was to establish how subjective visual evaluation correlates with electrical impedance spectroscopy and with traditional quality parameters. To do so, visual scoring was performed together with measurements of bioimpedance, color, and pH in two ham muscles (Adductor, Semimembranosus) for 136 animals 24-hours post-mortem. When comparing with visual scoring, Pearson correlation analysis shows the strongest correlation for bioimpedance (<i>P<sub>y</sub></i> , r = -0.46, R<sup>2</sup> = 21%), followed by pH<sub>u</sub> (r = 0.44, R<sup>2</sup> = 19%). When using all five quality measures, i.e., <i>P<sub>y</sub></i> , pH<sub>u</sub>, and CIELAB <i>L</i> <sup>*</sup> <i>a</i> <sup>*</sup> <i>b</i> <sup>*</sup>, the multivariate regression model had a prediction error of 0.76 for the visual scores. This was close to the error describing the subjective bias of visual scoring, more specifically the prediction error between the two observers (0.85). In all, <i>P<sub>y</sub></i> showed the strongest correlation among instrument-based quality tests and alone may be used for predicting pork ham structural defects, i.e., as an instrument-based alternative for subjective, visual scoring. However, an instrument that combines <i>P<sub>y</sub></i> with pH and/or <i>L</i>*<i>a</i>*<i>b</i>* would improve the prediction of PSE-like quality defects.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"75-84"},"PeriodicalIF":0.0,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11213458/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141471315","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}
Hoang Nhut Huynh, Quoc Tuan Nguyen Diep, Minh Quan Cao Dinh, Anh Tu Tran, Nguyen Chau Dang, Thien Luan Phan, Trung Nghia Tran, Congo Tak Shing Ching
{"title":"Machine learning-enhanced gesture recognition through impedance signal analysis.","authors":"Hoang Nhut Huynh, Quoc Tuan Nguyen Diep, Minh Quan Cao Dinh, Anh Tu Tran, Nguyen Chau Dang, Thien Luan Phan, Trung Nghia Tran, Congo Tak Shing Ching","doi":"10.2478/joeb-2024-0007","DOIUrl":"10.2478/joeb-2024-0007","url":null,"abstract":"<p><p>Gesture recognition is a crucial aspect in the advancement of virtual reality, healthcare, and human-computer interaction, and requires innovative methodologies to meet the increasing demands for precision. This paper presents a novel approach that combines Impedance Signal Spectrum Analysis (ISSA) with machine learning to improve gesture recognition precision. A diverse dataset that included participants from various demographic backgrounds (five individuals) who were each executing a range of predefined gestures. The predefined gestures were designed to encompass a broad spectrum of hand movements, including intricate and subtle variations, to challenge the robustness of the proposed methodology. The machine learning model using the K-Nearest Neighbors (KNN), Gradient Boosting Machine (GBM), Naive Bayes (NB), Logistic Regression (LR), Random Forest (RF), and Support Vector Machine (SVM) algorithms demonstrated notable precision in performance evaluations. The individual accuracy values for each algorithm are as follows: KNN, 86%; GBM, 86%; NB, 84%; LR, 89%; RF, 87%; and SVM, 87%. These results emphasize the importance of impedance features in the refinement of gesture recognition. The adaptability of the model was confirmed under different conditions, highlighting its broad applicability.</p>","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"63-74"},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11165689/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141306950","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}
Steffen Maude Fagerland, Henrik Røsholm Berntsen, Mats Fredriksen, Tor Endestad, Stavros Skouras, Mona Elisabeth Rootwelt-Revheim, Ragnhild Marie Undseth
{"title":"Exploring protocol development: Implementing systematic contextual memory to enhance real-time fMRI neurofeedback.","authors":"Steffen Maude Fagerland, Henrik Røsholm Berntsen, Mats Fredriksen, Tor Endestad, Stavros Skouras, Mona Elisabeth Rootwelt-Revheim, Ragnhild Marie Undseth","doi":"10.2478/joeb-2024-0006","DOIUrl":"10.2478/joeb-2024-0006","url":null,"abstract":"<p><strong>Objective: </strong>The goal of this study was to explore the development and implementation of a protocol for real-time fMRI neurofeedback (rtfMRI-nf) and to assess the potential for enhancing the selective brain activation using stimuli from Virtual Reality (VR). In this study we focused on two specific brain regions, supplementary motor area (SMA) and right inferior frontal gyrus (rIFG). Publications by other study groups have suggested impaired function in these specific brain regions in patients with the diagnoses Attention Deficit Hyperactivity Disorder (ADHD) and Tourette's Syndrome (TS). This study explored the development of a protocol to investigate if attention and contextual memory may be used to systematically strengthen the procedure of rtfMRI-nf.</p><p><strong>Methods: </strong>We used open-science software and platforms for rtfMRI-nf and for developing a simulated repetition of the rtfMRI-nf brain training in VR. We conducted seven exploratory tests in which we updated the protocol at each step. During rtfMRI-nf, MRI images are analyzed live while a person is undergoing an MRI scan, and the results are simultaneously shown to the person in the MRI-scanner. By focusing the analysis on specific regions of the brain, this procedure can be used to help the person strengthen conscious control of these regions. The VR simulation of the same experience involved a walk through the hospital toward the MRI scanner where the training sessions were conducted, as well as a subsequent simulated repetition of the MRI training. The VR simulation was a 2D projection of the experience.The seven exploratory tests involved 19 volunteers. Through this exploration, methods for aiming within the brain (e.g. masks/algorithms for coordinate-system control) and calculations for the analyses (e.g. calculations based on connectivity versus activity) were updated by the project team throughout the project. The final procedure involved three initial rounds of rtfMRI-nf for learning brain strategies. Then, the volunteers were provided with VR headsets and given instructions for one week of use. Afterward, a new session with three rounds of rtfMRI-nf was conducted.</p><p><strong>Results: </strong>Through our exploration of the indirect effect parameters - brain region activity (directed oxygenated blood flow), connectivity (degree of correlated activity in different regions), and neurofeedback score - the volunteers tended to increase activity in the reinforced brain regions through our seven tests. Updates of procedures and analyses were always conducted between pilots, and never within. The VR simulated repetition was tested in pilot 7, but the role of the VR contribution in this setting is unclear due to underpowered testing.</p><p><strong>Conclusion: </strong>This proof-of-concept protocol implies how rtfMRI-nf may be used to selectively train two brain regions (SMA and rIFG). The method may likely be adapted to train any given region in the brain","PeriodicalId":38125,"journal":{"name":"Journal of Electrical Bioimpedance","volume":"15 1","pages":"41-62"},"PeriodicalIF":0.0,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11141335/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141200537","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}