Journal of Electrical Bioimpedance Feed

Bioimpedance-based evaluation of relative leaf age in mango twigs using electrical impedance spectroscopy

Sat, 21 Mar 2026 00:00:00 GMT

This study proposes a non-destructive method for estimating the relative age of mango leaves using electrical impedance spectroscopy (EIS) and a modified double-shell equivalent circuit model. Impedance measurements were conducted on six mango varieties using five leaves per variety representing different positions along the twig. The Nyquist plots showed increasing circular arc diameters with leaf position, indicating higher charge transfer resistance in older leaves. Fitting results revealed that R1 increased while C1 decreased systematically with leaf age. Spearman correlation analysis confirmed a strong positive correlation between R1 and leaf position and a strong negative correlation for C1, whereas n1 showed no significant relationship. Linear regression yielded high coefficients of determination for most varieties. The selection of R1 and C1 as electrical indicators was supported by their low fitting errors, strong correlations, and consistent regression performance. These results demonstrate that EIS provides a rapid and reliable non-destructive approach for assessing the physiological age of mango leaves.

Feasibility of electrochemical impedance spectroscopy for in situ detection of water stress in plants

Tue, 17 Mar 2026 00:00:00 GMT

Electrochemical impedance spectroscopy (EIS) has been widely applied to bioimpedance measurements in human and animal systems; however, its potential for direct plant monitoring remains less explored. This study uses Komatsuna (Brassica rapa) to examine the feasibility of using EIS for in situ detection of plant water stress. Impedance spectra are measured noninvasively and analyzed using an equivalent circuit model designed to separate plant-related electrical properties from the electrode–plant interface. Changes in the low-frequency impedance region were observed under both irrigation and drying conditions, while the high-frequency response remained relatively stable. In particular, variations in the extracellular resistance parameter (Ro) preceded visible water-stress symptoms and continued even after visual changes became indistinguishable. Although the number of tested plants was limited, these results suggested the potential of EIS as a rapid and cost-effective tool for early, in situ assessment of plant water status. The present study provides a proof-of-concept for extending bioimpedance-based approaches to plant systems, with implications for precision agriculture and plant physiology research.

Finite element modeling of human thorax for electrical bioimpedance based monitoring of pulmonary fluid accumulation

Sun, 15 Mar 2026 00:00:00 GMT

Monitoring fluid accumulation in the lungs is critical in conditions such as pulmonary edema and pneumonia. Current diagnostic modalities, including auscultation, chest X-ray, computed tomography, magnetic resonance imaging, and ultrasonography, either involve ionizing radiation or are not suitable for continuous long-term monitoring. This study investigated the feasibility of a non-invasive, non-ionizing electrical impedance–based approach for continuous assessment of pulmonary fluid accumulation using computational modeling. Firstly, CT images of human subjects were used to build a simplified thorax model. Different parts of human thorax including airways, left and right lungs, and soft tissue were segmented using a segmentation software Materialise Mimics® and imported into COMSOL Multiphysics® for finite element analysis. Tetrapolar transfer impedance was computed at multiple vertical electrode positions under baseline (air-filled lung) and fluid-accumulation conditions. The results demonstrated a measurable reduction in impedance in the presence of fluid, particularly at electrode levels corresponding to the fluid-filled lower lobes. A linear relationship between impedance and fluid volume was observed (R2 = 0.9972 for the left lung and R2 = 0.9998 for the right lung), with sensitivities of −466.74 mΩ/100 mL and −754.75 mΩ/100 mL, respectively. For clinically relevant fluid accumulations (≥300 mL), the predicted impedance change exceeded 2 Ω, indicating practical detectability. Frequency-domain analysis (5–1000 kHz) further demonstrated consistent impedance contrast across the investigated range. These findings suggest that tetrapolar electrical impedance measurements have the potential for continuous monitoring of pulmonary fluid changes and provide a foundation for future experimental validation in human subjects.

When measurement outpaces meaning: Bioimpedance in Organ-on-Chip systems

Wed, 07 Jan 2026 00:00:00 GMT

Toe digit pulsation measurement by impedance plethysmography in miniaturized devices: An early feasibility test

Wed, 31 Dec 2025 00:00:00 GMT

This early feasibility test explores impedance plethysmography (IPG) for detecting toe pulse waves using a setup suited for miniaturized devices. Conventional tests often miss micro-circulatory impairment, which is critical for wound healing and limb survival. We designed a flexible 3D-printed clamp with Ag/AgCl electrodes positioned on the inner big toe to target the lateral plantar digital artery. 50 kHz impedance measurements were performed on a healthy volunteer using 3D-printed electrode clamp for a tetrapolar configuration. Custom designed flexible electrodes were tested with and without contact gel. Preliminary results suggest that IPG can capture distal pulsatile signals, motivating further exploration of the potential for early detection of peripheral vascular dysfunction.

Using neuromorphic computing in prediction of GABA concentration – a pilot study

Mon, 29 Dec 2025 00:00:00 GMT

Neuromorphic computing has the potential to facilitate detection of GABA concentration levels in the brain, and offers energy-efficient, real-time machine learning processing possibilities. To study whether neuromorphic computing can be used for GABA concentration detection, dielectric relaxation spectroscopy was used to acquire permittivity data of different concentrations of GABA solution. Thereafter, two different machine learning models were compared (Feedforward neural network (FFNN) and convolutional neural network (CNN)) for accuracy in prediction of GABA concentration from dielectric properties. The CNN model was then converted to spiking Neural Networks (SNNs), which showed promising results for energy efficiency and real-time processing capabilities. The system incorporates Tkinter, a Python interface to the Tcl/Tk GUI toolkit for seamless data transfer between the neuromorphic chip and the measurement system, ensuring flexibility and scalability in a user-friendly system.

Changes in bioelectrical and non-bioelectrical variables associated with overweight after a weight-loss program based on intestinal microbiota modulation

Wed, 17 Dec 2025 00:00:00 GMT

Objective To assess changes in clinical and bioelectrical impedance analysis (BIA) variables associated with overweight, after a 6-day weight-loss protocol based on intestinal microbiota modulation. Methods A group of 12 young overweight women (OG) were randomly assigned to either a control subgroup (COG, n=6) or an experimental subgroup (EOG, n=6), while, for comparison, eight lean healthy women served as reference (LG). The intervention combined a liquid diet, probiotics, psyllium, bentonite, and a daily open-system trans-anal irrigation. 23 clinical variables not involving BIA (type BIA-0: 12 physical, 9 chemical and 2 biological), and 21 variables obtained by BIA were measured at 4 time points (T1-T4), in a time lapse of 10 weeks. 11 BIA variables were designed as BIA-1, i.e., proper bioimpedance variables, and 10 as BIA-2, i.e., those calculated by a combination of BIA-0 and BIA-1 variables. Intestinal microbiota (IMB) modulation was explored via two biological variables: Firmicutes/Bacteroidota ratio and Akkermansia muciniphila relative prevalence. All variables (except age and height) were also divided in two subtypes: “+”, those usually higher in overweight people, whose median values were expected to decrease after the intervention (a total of 26), and “−”, those usually lower in overweight people, whose medians values were expected to increase with the intervention (a total of 16). Results all 42 variables susceptible to changes with the intervention changed in a favorable direction (their median values moved towards those of the LG), with 32 of the changes showing statistical significance. Conclusions In this pilot study, a multimodal microbiota-oriented protocol was associated with consistent and, mostly, clinically meaningful improvements of bioelectrical and physiological markers in overweight young women. Changes in BIA parameters seem to mirror the physiological changes detected in BIA-0 variables. Larger and longer trials are warranted to confirm these findings.

Cycling exercise efficiency and economy: Exploring the role of phase angle

Fri, 12 Dec 2025 00:00:00 GMT

BackgroundPhase angle (PhA), derived from bioelectrical impedance analysis (BIA), is considered a non-invasive marker of cellular health and membrane integrity. Whether PhA relates to muscular efficiency during exercise remains unclear. MethodsThis pilot study investigated the association between PhA and delta efficiency (DE), gross efficiency (GE), and exercise economy (EC) during submaximal cycling in 30 healthy young adults (15 females, mean age 21.4 ± 3.8 years). Whole-body and lower-body PhA were assessed using multifrequency BIA. Participants completed a graded cycling test (20–80 W) with energy expenditure determined via indirect calorimetry. DE, GE, and EC were calculated using standard procedures, and associations with PhA were examined using Pearson correlations, median-split group comparisons, and multivariable linear regression models adjusting for sex and fat-free mass. ResultsNeither whole-body nor lower-body PhA was significantly correlated with DE, GE, or EC (all p > 0.05). Group comparisons based on PhA medians showed no significant differences in performance indicators. The largest observed correlation was between whole-body PhA and GE (r = −0.32, p = 0.081). Regression models adjusting for sex and fat-free mass confirmed that PhA did not independently predict DE, GE, or EC. ConclusionsPhA did not predict submaximal cycling efficiency or economy in healthy young adults. These findings suggest that cellular health, as reflected by PhA, may not directly influence muscular energetics under steady-state conditions. Future studies with larger samples and mechanistic measurements are warranted to clarify this relationship.

Effects of acute essential amino acid intake on post-prandial raw bioimpedance and fluid shifts between healthy young and older adults: An exploratory pilot study

Fri, 28 Nov 2025 00:00:00 GMT

Introduction Age-related anabolic resistance can lead to reduced muscle mass but can be costly and timely to diagnose. Multi-frequency bioelectrical impedance analysis could potentially be used as a non-invasive tool for the assessment of anabolic resistance as changes in frequency-dependent impedance values may reflect fluid shifts occurring with nutrient uptake. This exploratory pilot study evaluated the effects of acute essential amino acid (EAA) intake on raw bioimpedance and fluid shifts in healthy young adults (YA, n=5) and older adults (OA, n=7). Methods Participants completed a five-hour protocol with multifrequency bioelectrical impedance analysis (MF-BIA) at baseline and every 30 minutes post-consumption of a 10 g EAA beverage. Whole-body and segmental values for impedance (Z), resistance (R), reactance (Xc), phase angle (PhA), and body water compartments were assessed. Results YA demonstrated significantly higher Z, R, Xc, and PhA values compared to OA (p<0.05), particularly in the leg segments and at 50 kHz. Time effects revealed declines in R (p=0.013) and Xc (p=0.002) following EAA ingestion, consistent with postprandial fluid shifts. Fluid analysis showed significant group differences only for ECW/ICW ratio (p=0.001–0.004) with OA > YA and increases in TBW, ICW, and ECW over time. Conclusion Raw bioimpedance values distinguished between age groups and reflected acute responses to nutrient intake. These findings suggest MF-BIA may be sensitive to short-term physiological changes and, with further validation, could support assessments of muscle quality and nutritional responsiveness.

Cell membrane capacitance relationship to reference-measured body composition parameters in young adult athletes

Tue, 14 Oct 2025 00:00:00 GMT

Cell membrane capacitance (Cm) is considered a measure of cellular health. This study evaluated the relationship between bioimpedance spectroscopy-measured Cm and multicomponent model reference-measured body composition variables from air displacement plethysmography and dual-energy x-ray absorptiometry in a sample of 226 young adult athletes. Men (3.00 ± 0.62 nF) had greater (p < 0.001) Cm than women (1.90 ± 0.36 nF). Variables indicative of lean mass, such as fat-free mass index, had a strong (r > .70) direct relationship with Cm. The Cm relationship was moderate for measures related to body mass and bone health (r = .30 to .60) and weak (r < .20) for fat mass. The relationship between Cm and body composition variables is strongest for the fat-free components.

Electrical impedance myography as a marker of muscle mass in rats with simulated Anorexia Nervosa

Wed, 06 Aug 2025 00:00:00 GMT

Motivation Anorexia Nervosa (AN) is characterized by a severe reduction in caloric intake resulting in substantial weight loss. Methods to evaluate muscle loss specifically during AN or following a weight recovery intervention are difficult to administer and expensive. Purpose To evaluate the utility of electrical impedance myography (EIM) to assess changes to muscle mass during simulated AN and different durations of weight recovery in rats. Methods Female Sprague-Dawley rats (n=11/group, total of 66 rats, 8 weeks old) were divided into simulated AN or healthy control conditions. Simulated AN included 30 days of 50–60% food restriction. Following AN intervention, rats were further subdivided into recovery cohorts which included five, fifteen, or thirty days of ab libitum food consumption to elicit weight gain. EIM was assessed at various stages of weight loss and recovery and correlated to metrics of muscle mass. Results Various EIM parameters detected changes in muscle mass both during simulated AN and following weight restoration. The resistance parameter produced the most consistent results during simulated AN and following various stages of weight recovery. Moreover, the resistance parameter had the highest correlation with gastrocnemius mass (r = ~0.50, p<0.05). Maximal tetanic plantar flexion was also analyzed but did not correlate with any EIM parameters. Conclusion EIM can non-invasively detect changes to muscle mass during AN and following various states of weight recovery.

Predictive classification and regression models for bioimpedance vector analysis: Insights from a southern Cuban cohort

Mon, 04 Aug 2025 00:00:00 GMT

This study used predictive models to explore the link between bioparameters at characteristic frequency and their positions within tolerance ellipses in a southern Cuban cohort. The database includes 367 individuals (235 females, 132 males) aged 18–86. Among them, 61 had cancer, while 306 were healthy. After balancing the data, the analysis used 16 bioimpedance-based characteristics along with other anthropometric and location factors. The results showed that characteristic frequency bioparameters (Zc, θc, Xcc, and Rc) are key for assessing health and location. There was a strong agreement between experimental and predicted values for Zc, θc, Xcc, and Rc across various categories. Cancer patients showed higher Zc and slightly lower θc and Xcc values, attributed to unbalanced body composition and cell membrane deterioration. Females exhibited higher Zc and Xcc values, indicating better cell membrane integrity. Predictions are consistent across quartiles and percentiles, with lower θc observed in higher quartiles and centiles where more cancer patients are located. Variations in Rc values across different BIVA statuses demonstrated the model's robustness in estimating impedance parameters in diverse physiological conditions. These predictive models are significant for assigning locations without developing BIVA methods, enhancing clinical assessments and health monitoring.

Assessing the consistency between the anthropometric method and bioelectrical impedance analysis when calculating the Heath-Carter somatotype in people without obesity: a cross-sectional study

Mon, 04 Aug 2025 00:00:00 GMT

Body physique assessment is important for various fields of science and practice, including anthropology, medicine, sports nutrition and pedagogy. The classic Heath-Carter method is complex and multi-step, while bioelectrical impedance analysis makes it easier and faster to evaluate this parameter. The purpose of this study is a comparative analysis of the anthropometric method and bio-electrical impedance analysis in assessing the somatotype. Differences and a low degree of agreement were found between these methods in determining the somatotype. Study designStudies were carried out at the Department of Anatomy and Biological Anthropology of the Russian University of Sports “SCOLIPE” (Russia) and the morphological departments of the medical faculties of Osh State University (OshSU) of the Kyrgyz Republic from February to April 2024. ResultsBioelectrical impedance analysis quickly and more significantly speeds up the process of assessing a person's body type. ConclusionBioimpe-dance analysis shows an increased level of mesomorphy scores in both males and females, and the difference in males is more pronounced. On the other hand, endomorphy scores were lower when assessing the somatotype using the anthropometric method.

Early thrombus detection in ECMO with optimized impedance measurements: A simulative study

Tue, 01 Jul 2025 00:00:00 GMT

Extracorporeal oxygenation supports patients with severe cardiac or respiratory failure, with the oxygenator providing critical gas exchange. Thrombus formation in the oxygenator can impair efficiency and increase risks such as hemolysis and embolism, but existing detection methods are limited in accuracy and timeliness. This study introduces a computational bioimpedance approach for early thrombus detection that integrates advanced modeling and machine learning techniques while preserving the oxygenator’s functionality. We developed a finite element model of an oxygenator to simulate bioimpedance measurements using varied electrode configurations. Neural networks optimized electrode placement and injection-measurement patterns, enhancing sensitivity to conductivity changes. A second neural network was trained on simulated data to distinguish between normal and thrombus-affected conditions, achieving an F1-score exceeding 94% in classification tasks. Simulations demonstrated the feasibility of this method, with optimized configurations significantly improving detection accuracy. The findings suggest that computational bioimpedance, combined with neural network optimization, provides a robust framework for automated thrombus detection inside an oxygenator.

Wireless power system for left ventricular assist device: Influence of coil design and tissue behavior on efficiency

Mon, 16 Jun 2025 00:00:00 GMT

This paper proposes a compact wireless power transfer (WPT) system designed to energize an implanted heart pump. The design integrates several power converters: a buck-boost converter supplied by a 14-volt battery, an H-bridge inverter, a low-pass filter, and a resonant inductive coupling WPT unit. A resistive load of 40 ohms is used to simulate the equivalent pump's operation. To improve efficiency and limit power losses caused by high-frequency skin effects, a Litz wire is utilized. Consequently, a multi-layer transmission coil structure is employed to strengthen coupling and ensure deeper field penetration. The system operates in an open-loop configuration with manual adjustment of the DC-DC converter's duty cycle. A frequency of 6.78 MHz is selected based on the Industrial, Scientific, and Medical band due to its recognized safety and its ability to achieve deeper penetration into biological tissues. To optimize the design, precise mathematical modeling of both the WPT system and the tissue layers is conducted, simulating their impact on electromagnetic field behavior. Simulation results demonstrate an impressive power transfer efficiency of 91% across a separation of 60 mm. It is worth noting that most existing studies focus on low-power wireless energy delivery for internal medical devices; this research advances the field by targeting higher power demands, positioning it as a practical solution for critical applications like heart assist pumps.

Novel bioparameters derived from bioimpedance measurements for accurate prediction of weight status in infant–juvenile individuals: A regression analysis

Mon, 26 May 2025 00:00:00 GMT

In this study, a linear support vector machine regression model was used to explore the correlation between weight status and two novel bioparameters, specific resistance and reactance, in an infant-juvenile cohort from eastern Cuba. The model was trained using various characteristics, including bioimpedance measurements, to predict phase angle, specific resistance, and reactance with high accuracy. The results showed that the variation of these characteristics with weight status and sex is consistent with previous literature. Additionally, two robust bioparameters derived from bioimpedance measurements and anthropometric-physiological parameters were identified for predicting weight status. The predictive models developed in this study are essential for accurately assessing weight status and disease risks in infants and juveniles in the eastern Cuban region. These findings highlight the potential applications of bioimpedance measurements and bioparameters in health and disease risk assessment, contributing to the growing body of literature on this topic.

Comparative analysis of body composition results of university students obtained using two bioimpedance analyzers

Tue, 06 May 2025 00:00:00 GMT

Body composition is a key health indicator that distinguishes between fat mass and lean mass, factors associated with the risk of metabolic and cardiovascular diseases. Among measurement methods, bioelectrical impedance analysis (BIA) is widely used, with single- and multi-frequency devices showing differences in performance. Objective To compare the accuracy of the OMRON® HBF-514C (single-frequency) and BIODY XPERT ZM II® (multi-frequency) bioimpedance analyzers in measuring body composition in university students. Materials and Methods An observational, cross-sectional, and comparative study was con-ducted with 40 students (20 men, 20 women) from the University of Caldas, without a history of metabolic diseases. Body fat, muscle mass, basal metabolic rate (BMR), and BMI were measured using both devices. Data normality was assessed, and means were compared using the student’s t-test (p < 0.05). Results In women, Biody showed significantly higher values for body fat, muscle mass, and basal metabolic rate compared to Omron (p < 0.05), with no differences in BMI. In men, only muscle mass and basal metabolic rate were significantly higher with Biody (p < 0.05), with no differences in body fat or BMI. Conclusions Biody showed significantly higher values than Omron for muscle mass and basal metabolic rate. In women, the differences exceeded the acceptable 5% variability, suggesting that multifrequency devices may offer greater consistency. Although no gold standard was used, Omron could be a valid alternative in men.

Bioimpedance spectroscopy of breast phantoms

Fri, 18 Apr 2025 00:00:00 GMT

This article is devoted to the study of the possibility of detecting breast tumors, which can be used for early diagnostics of breast cancer, by the dielectric impedance spectroscopy method. Dielectric impedance spectroscopy is a version of the bioimpedance spectroscopy method, based on the concept of breast tissue as a heterogeneous dielectric, the electrical and mathematical models of which are based on the Havriliak-Negami model. This opens the possibility of getting rid of direct mechanical and electrical contacts between the electrical impedance sensors of the mammograph and the skin. To determine the sensitivity of the dielectric impedance spectroscopy (DIS) method, a series of experiments was performed with phantoms with and without inclusion based on physiological solution (isotonic saline solution) and agar-agar. Using a special capacitive sensor and an LCR meter, the frequency response of the phantoms was determined. Analysis of the statistical characteristics of the differences in the frequency response curves showed significant differences (up to 8% for active R and 4% for reactive X components). The results confirmed the operability of the dielectric impedance spectroscopy method. An important direction for further research is to determine the most informative frequency range.

Phase angle and extracellular edema predict risk of postoperative complications in total joint arthroplasties

Tue, 25 Mar 2025 00:00:00 GMT

IntroTotal 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. MethodsA 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. ResultsIn 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) ConclusionECW/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.

Gender differences in the effects of skin hydration on electrodermal activity measurements

Mon, 24 Mar 2025 00:00:00 GMT

Electrodermal activity (EDA) is defined as a general term for all electrical behaviors in the skin, encompassing all active and passive electrical properties that can be traced back to the skin and its appendages. EDA measurements can be impacted by various factors and conditions. A factor of effect on EDA recordings, which has not been investigated before is the gender-related differences in the effects of skin hydration on EDA signals. Hence, this study aimed to study gender-related differences in the EDA parameters under conditions of skin hydration. 30 males and 30 females participated in this study under two different conditional (normal and hydration) experiments. Three EDA parameters (tonic and phasic components) were recorded from both groups. In the hydration experiment, 0.2 gram of 0.5% KCI in a 2% agar jelly was applied to the skin of all participants to moisturize their skin. The data from both experiments were analyzed to investigate gender-related differences in the effects of skin hydration on EDA measurements. It was found that EDA measurements, in particular the tonic component were not influenced by gender-related differences under hydration conditions. However, some significant (p<0.05) differences were observed between males and females in certain phasic parameters in response to specific stimuli. This study suggests that skin hydration does not contribute to gender-related differences in EDA recordings. These results are probably important in EDA investigations and applications.