rss_2.0Sciendo RSS Feed for Journal of Electrical Bioimpedancehttps://sciendo.com/journal/JOEBhttps://www.sciendo.comhttps://sciendo-parsed.s3.eu-central-1.amazonaws.com/67971ede082aa65dea3db022/cover-image.jpghttps://sciendo.com/journal/JOEB140216https://sciendo.com/article/10.2478/joeb-2025-0005<abstract> <title style='display:none'>Abstract</title> <sec><title style='display:none'>Intro</title><p>Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common procedures that improve mobility but carry a risk of postoperative complications, particularly in patients with obesity. Body Mass Index (BMI) is traditionally used for risk assessment but does not account for muscle mass or fat distribution. Bioelectrical impedance analysis (BIA) provides a more detailed body composition evaluation. This study investigates the association between BIA-derived metrics and postoperative complications in TKA and THA, hypothesizing that these metrics are superior predictors compared to BMI.</p></sec> <sec><title style='display:none'>Methods</title><p>A retrospective cohort study was performed on 567 adult patients who underwent primary THA or TKA from January 2020 to December 2023. The data collected included demographic characteristics, comorbidities, preoperative laboratory values, preoperative BIA measurements and postoperative complications. Multivariate logistic regression models were developed to identify independent predictors of postoperative complications. Receiver operating characteristic (ROC) curves assessed the predictive accuracy of BIA-metrics models compared to BMI model.</p></sec> <sec><title style='display:none'>Results</title><p>In a cohort of 567 patients (55.7% female, median age 66), no significant difference in BMI was found between the complication and non-complication groups. However, the complication group had a higher ECW/TBW ratio (0.396 vs. 0.393, p = 0.011), higher ECW/ICW ratio (0.657 vs. 0.647, p = 0.012), and a lower phase angle (4.65 vs. 4.80, p = 0.039). Multivariate logistic regression analysis revealed that higher standardized ECW/TBW (OR 1.65, 95% CI 1.17–2.31, p = 0.004) and ECW/ICW z-scores (OR 1.61, 95% CI 1.15–2.23, p = 0.005) were associated with increased odds of postoperative complications, while a lower phase angle was protective (OR 0.58, 95% CI 0.37–0.91, p = 0.018). ROC analysis showed moderate predictive accuracy for ECW/TBW (AUC 0.71, 95% CI 0.62–0.79), ECW/ICW (AUC 0.70, 95% CI 0.62–0.79), and phase angle (AUC 0.69, 95% CI 0.60–0.79). In contrast, BMI was not significantly associated with complications, and BMI model demonstrated inferior predictive accuracy (AUC 0.61)</p></sec> <sec><title style='display:none'>Conclusion</title><p>ECW/TBW, ECW/ICW and phase angle are associated with postoperative complications in patients undergoing primary TKA or THA. These metrics provide better predictive accuracy than BMI enhancing preoperative risk stratification.</p></sec> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2025-00052025-03-25T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2025-0004<abstract> <title style='display:none'>Abstract</title> <p>In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI) are well-known fertility treatments that, due to resource-intensive, high degree of expertise required, and frequent subpar performances, often yield in high costs for treatment cycles. Microfluidic technology has enabled cost-effective egg-handling procedures towards new assistive reproductive devices: oocytes are subjected to microchannels with jagged surfaces to let shear stress remove undesirable cumulus cells, and microchannels with expansion units facilitate the transport of oocytes in chips. However, although the previous works have studied the influence of shear stress on oocyte denudation and the role of microchannel teeth in optimizing cell handling efficiency, the study of configurations of jagged surfaces and expansion units in microfluidic devices has remained elusive. Also, comprehensive analysis using both computational fluid dynamics (CFD) and real-world microfluidic devices has remained an unexplored area. To fill the abovementioned gap, this paper studies microfluidics chips with different expansion units to depict the behavior of oocytes when subjected to controlled input flows. The proposed chips were developed and fabricated using a direct engraving CO₂ laser machine on polymethyl methacrylate (PMMA) sheets and bonded in a natural ventilation lab oven, rendering the highly efficient and low-cost microfluidic chips for oocyte denudation. The effect of the expansion units has been investigated in CFD simulation and real lab experimentation with mature buffalo oocytes at a constant flow rate, and a chip with five expansion units arranged in two lines achieved 98.33% denudation efficiency, low-cost fabrication (about 1 USD), and quick fabrication time (about 20 minutes).</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2025-00042025-03-20T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2025-0003<abstract> <title style='display:none'>Abstract</title> <p>Electrical Impedance Tomography (EIT) is a non-invasive method for imaging conductivity distributions within a target area. The inverse problem associated with EIT is nonlinear and ill-posed, leading to low spatial resolution reconstructions. Iterative algorithms are widely employed to address complex inverse problems. However, current iterative methods have notable limitations, such as the arbitrary and subjective selection of initial parameters, lengthy computational times due to numerous iterations, and the generation of reconstructions that suffer from shape blurring and a lack of higher-order detail. To address these issues, this study investigates the impact of using ISTA and FISTA iterative algorithms on the image reconstruction process in EIT. It focuses on enhancing the convergence and accuracy of EIT image reconstruction by evaluating the effectiveness of these optimization algorithms when applied to regularized inverse problems, using standard regularization techniques. ISTA and FISTA were compared to the NOSER and Newton-Raphson methods and validated through simulation and experimental results. The results show that ISTA and FISTA achieve better visualization and faster convergence than conventional methods in terms of computational efficiency when solving regularized problems, achieving conductivity reconstructions with an accuracy of above 80%. The paper concludes that while ISTA and FISTA significantly enhance EIT image reconstruction performance, the quality of the reconstructed images heavily depends on the choice of regularization methods and parameters, which are crucial to the reconstruction process.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2025-00032025-03-11T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2025-0002<abstract> <title style='display:none'>Abstract</title> <p>The Focused Impedance method (FIM), an innovation by Dhaka University, Bangladesh, is a new technique for focusing a region of interest of a volume conductor through a simple enhancement of the age-old Tetra-Polar Impedance Method (TPIM). This innovation has potential in the diagnosis of different kinds of physiological disorders.</p> <p>This paper presents the study of lung ventilation on different human subjects using the six-electrode version of the Focused Impedance Method (FIM-6) with the circuit indigenously designed in Nepal. The study was carried out for different quadrants of the lungs of three normal male subjects using both TPIM and FIM-6 configurations, measuring the percentage change in transfer impedance between full inspiration and full expiration. The percentage changes observed were in the range of 15% to 27%. However, errors are expected due to movement of the heart and other organs between inspiration and expiration, which may be difficult to eliminate.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2025-00022025-02-19T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2025-0001ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2025-00012025-01-15T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0020<abstract> <title style='display:none'>Abstract</title> <p>Wearable and portable devices are gaining significant popularity across consumer electronics as well as in medical and industrial fields. To ensure that these devices are both comfortable and appealing to users, they need to have low battery consumption and be compact in both size and weight. The EGluco project is focused on developing a wearable device for non-invasive blood glucose monitoring. This multi-sensor device incorporates electrical bioimpedance spectroscopy as one of its measurement techniques. One of the earlier versions of the device was deemed unsuitable as a wearable due to its large size and high power consumption. To make the device more suitable for wearability, the previous hardware was assessed, and a new design was proposed that simplified the system’s power supply and reduced the operating voltage. This article presents two of these designs: an improved Howland current source with a supply voltage of 3.3 V, an output current of 250 <italic>μA</italic>, and the ability to conduct bioimpedance analysis up to 1 MHz using pulsed DIBS (Discrete Interval Binary Sequence) signals, and an instrumentation amplifier with the same supply voltage as the current source, a voltage gain of four, and a slew rate of 150 <italic>V/μs</italic>. By simplifying the power supply and implementing other changes, the device’s size was reduced to a single 5 × 5 cm circuit board, compared to the previous configuration of four separate boards connected by cables.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00202025-01-04T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-1024-0019<abstract> <title style='display:none'>Abstract</title> <p>The conductive polymeric electrodes using 3D printing are an innovative material development with the advantage of the flexibility of integrating isolated polymers with a higher electrical conductivity of carbon-based materials, generating new possibilities in environmental, healthcare, and food monitoring. Based on the morphology, geometric arrangement, and dielectric properties of the composites, the performance of the electrodes is improved. Structural designs are optimized to enhance functionalities such as adhesion, catalytic activity, and the reduction of interface energy. With these concepts, a functionalized carbon-based polymeric electrode was fabricated using 3D printing. The Differential Impedance Spectrum (DIS) was employed to analyze the response of functionalized electrodes to solutions of acetic acid and calcium chloride (<italic>CaCl₂</italic>). DIS data extract the differential phase angle and indicate the interactions between the functionalized surface with acetic acid and <italic>CaCl₂</italic> solutions, showing noticeable peaks in three zones: at lower frequencies (&lt; 10 kHz), medium frequencies range of 10 kHz to 100 kHz, and higher frequencies (&gt; 100 kHz). In the three cases analyzed, the <italic>CaCl₂</italic> solution presented the highest frequency compared with acetic acid. When the sensor was doubled functionalized, the peaks were shifted between the range of 220 kHz to 280 kHz. A conclusion is that the carbon-based polymer electrode not only reduces manufacturing costs but also enables faster functionalization to detect specific chemical compounds in liquids quickly and portable without the need for higher-level equipment. These electrodes could be applied to make measurements in aqueous media such as ponds, pools, lakes, rivers, and oceans to detect contaminants, as well as in human fluids to recognize metabolites in sweat, urine, saliva, and blood.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-1024-00192024-12-23T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0018<abstract> <title style='display:none'>Abstract</title> <p>Electrical bioimpedance is based on the opposition exerted by body tissues to the passage of an electrical current. This characteristic allows the assessment of the individual's body composition, nutritional status, and hydration status. Electrical bioimpedance can be used to estimate body composition, health-related markers, general health status, diagnosis and prognostic of diseases, evaluation of treatment progress, and others. The aim of this study is to propose a methodology that allows us to integrate two methods of electrical bioimpedance analysis: bioelectrical impedance vector analysis, and bioelectrical impedance spectroscopy to evaluate the health of individuals.</p> <p>For methodology validation a retrospective clinical investigation was carried out where the data of healthy individuals and cancer patients included in the Database of the characterization of bioelectrical parameters by electrical Bioimpedance methods were analyzed.</p> <p>The values of electrical resistance and electrical reactance are higher in cancer patients compared to healthy individuals. However, the phase angle is lower in these patients. In the advanced stages of the disease, patients are located outside the tolerance ellipses. All these results are obtained at the characteristic frequency.</p> <p>The integration of bioelectrical impedance vector analysis, and bioelectrical impedance spectroscopy can be a sensitive complementary tool, capable of establishing differences between healthy individuals and cancer patients. Enrichment could be achieved by including the analysis of different physiological parameters through estimation equations validated by BIS parameters.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00182024-12-17T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0015<abstract> <title style='display:none'>Abstract</title> <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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00152024-10-05T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0016<abstract> <title style='display:none'>Abstract</title> <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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00162024-10-05T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0017<abstract> <title style='display:none'>Abstract</title> <p>Bio-impedance Spectroscopy (BIS) is a technique that allows tissue analysis to diagnose a variety of diseases, such as medical imaging, cancer diagnosis, muscle fatigue detection, glucose measurement, and others under research. The development of CMOS integrated circuit front-ends for bioimpedance analysis is required by the increasing use of wearable devices in the healthcare field, as they offer key features for battery-powered wearable devices. These features include high miniaturization, low power consumption, and low voltage power supply. A key circuit in BIS systems is the current source, and one of the most common topology is the Enhanced Howland Current Source (EHCS). EHCS is also used when the current driver is driven by a pseudo-random signal like discrete interval binary sequences (DIBS), which, due to its broadband nature, requires high performance operational amplifiers. These facts lead to the need for a current source more compatible with DIBS signals, ultra-low power supply, standard CMOS integrated circuit, output current amplitude independent of input voltage amplitude, high output impedance, high load capability, high output voltage swing, and the possibility of tetra-polar BIS analysis, that is a pseudotetra-polar in the case of EHCS. The objective of this work is to evaluate the performance of the Switching CMOS Current Source (SCMOSCS) over EHCS using a Cole-skin model as a load using SPICE simulations (DC and AC sweeps and transient analysis). The SCMOSCS demonstrated an output impedance of more than 20 <italic>M</italic>Ω, a ± 2.5 <italic>V</italic> output voltage swing from a +3.3 V supply, a 275 <italic>μA</italic> current consumption, and a 10 <italic>k</italic>Ω load capacity. These results contrast with the + 1.5 V output voltage swing, the 3 <italic>k</italic>Ω load capacity, and the 4.9 <italic>mA</italic> current of the EHCS case.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00172024-10-05T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0014<abstract> <title style='display:none'>Abstract</title> <p>The current stage of development of medical science is characterized by growing interest in constitutional typology and clinical anthropology. The anatomical-anthropological approach is an integrative technique of biology and medicine that allows us to determine the criteria for normality and pathology of a person. <italic>Purpose of the study:</italic> comparative bioimpedance assessment of somatic types of body component composition among the first mature age period people residing in highland. <italic>Study design:</italic> a comparative bioimpedance assessment of body types according to the Heath and Carter’s scheme was performed to identify somatic types and body weight composition in healthy men of the 1^st adulthood period living in high mountains (2469–3325 m above sea level). Somatotypical features of body composition have been established. An intertype and correlation analysis of body composition was conducted in individuals with different body types. <italic>Results:</italic> comparative bioimpedance and correlation analyses revealed differences in body composition indicators depending on population, age, body types and living conditions. <italic>Conclusion:</italic> mesoectomorphy, balanced ectomorphic, central and meso-endo types prevailed among the somatotype subgroups.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00142024-10-05T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0013<abstract> <title style='display:none'>Abstract</title> <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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00132024-09-17T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0012<abstract> <title style='display:none'>Abstract</title> <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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00122024-09-06T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0011<abstract> <title style='display:none'>Abstract</title> <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 <italic>f</italic>^cancer. The EIT-GRTD has two steps, which are 1) the determination of the <italic>f</italic>^cancer 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 <italic>σ</italic> and permitivitty <italic>ε</italic>, inherent to two major breast tissues: adipose tissues, and breast cancer tissues. In this case, the <italic>σ</italic> and <italic>ε</italic> of breast cancer <italic>σ</italic>^cancer, <italic>ε</italic>^cancer are higher than adipose tissues <italic>σ</italic>^adipose, <italic>ε</italic>^adipose. The simulation results indicate that the most effective frequency for breast cancer detection based on EIT-GRTD is <italic>f</italic>^cancer = 56,234 Hz. Meanwhile, conventional EIT requires more processing to determine the <italic>f</italic>^cancer 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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00112024-08-12T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0010<abstract> <title style='display:none'>Abstract</title> <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/m²) 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&lt;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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00102024-08-05T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0009<abstract> <title style='display:none'>Abstract</title> <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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00092024-07-03T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0008<abstract> <title style='display:none'>Abstract</title> <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 (<italic>P_y</italic>, r = −0.46, R² = 21%), followed by pH_u (r = 0.44, R² = 19%). When using all five quality measures, i.e., <italic>P_y</italic>, pH_u, and CIELAB <italic>L</italic>^* <italic>a</italic>^* <italic>b</italic>^*, 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, <italic>P_y</italic> 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 <italic>P_y</italic> with pH and/or <italic>L</italic>*<italic>a</italic>*<italic>b</italic>* would improve the prediction of PSE-like quality defects.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00082024-06-28T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0007<abstract> <title style='display:none'>Abstract</title> <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> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00072024-06-11T00:00:00.000+00:00https://sciendo.com/article/10.2478/joeb-2024-0006<abstract> <title style='display:none'>Abstract</title> <sec> <title style='display:none'>Objective</title> <p>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> </sec> <sec> <title style='display:none'>Methods</title> <p>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.</p> <p>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> </sec> <sec> <title style='display:none'>Results</title> <p>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> </sec> <sec> <title style='display:none'>Conclusion</title> <p>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, but readers are advised to update and adapt the procedure to experimental needs.</p> </sec> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/joeb-2024-00062024-05-31T00:00:00.000+00:00en-us-1