Search Results (773)

Accurate color classification plays a critical role across diverse fields, from textile manufacturing and environmental monitoring to biomedical diagnostics. This study introduces a machine-learning-driven approach to spectral color sensing using SENSIPATCH, a compact, wearable sensor system; while SENSIPATCH integrates multiple sensing modalities, including bioimpedance, electrochemical, thermal, humidity, and vibrational sensors, this work specifically utilizes its spectrometer module, which comprises multi-wavelength LEDs and photodiodes. Targeting the classification of 100 standardized PANTONE colors, the proposed framework is evaluated under controlled lighting conditions to ensure repeatable spectral acquisition. The experimental design includes both firm and loose contact scenarios to emulate variability in wearable placement. A structured data-preprocessing pipeline involving baseline correction, bootstrapping, and Z-score normalization was employed to enhance signal quality and improve model generalization. Five machine learning models were evaluated: Random Forest, SVM, MLP, CNN, and LSTM. The MLP demonstrated the strongest classification performance. Notably, the MLP achieved consistent accuracy across both contact conditions, indicating robustness against sensor placement variations. These results highlight the feasibility of compact LED-based wearable spectroscopy for reliable color classification under controlled measurement conditions, providing a baseline for future extensions to more diverse lighting conditions. Full article

In vitro cell barrier models have been increasingly integrated into pharmaceutical and academic research pipelines to evaluate drug safety and drug delivery due to a shift towards New Approach Methodologies (NAMs) in research and regulatory safety assessment. Such models require reliable and interpretable functional readouts. Bioimpedance-based monitoring, particularly transepithelial/endothelial electrical resistance (TEER), is a widely adopted readout due to its non-invasive and real-time capabilities. However, substantial variability arises from differences in measurement settings, frequency selection, electrode configuration, impedance measuring techniques, and data analysis strategies. In numerous studies, TEER is approximated from single-frequency impedance magnitude measurements, which do not isolate the resistive component associated with tight junction-mediated paracellular transport but instead reflect the combined response of a coupled electrochemical system. This review clarifies impedance measuring techniques and systematically analyzes impedance-based measurement and analysis strategies for in vitro biological cell barrier integrity. We compare mono-frequency and broadband acquisition approaches, examine the influence of electrode–electrolyte interfaces, electrode geometry, and culture configuration, and evaluate equivalent circuit modeling and phase-resolved electrical impedance spectroscopy (EIS). Based on this comparison, we propose a three-level analytical hierarchy adapted to experimental objectives and instrumentation constraints. We conclude that phase-informed impedance analysis and harmonized reporting are essential to improve measurement reproducibility, inter-platform comparability, and integration of impedance-derived cell barrier assessment within NAMs-oriented research workflows. Full article

Chronic kidney disease is defined as a progressive pathology that affects more than 10% of the world’s population, affecting waste filtration capacity. Sarcopenia, characterized by loss of muscle mass and strength, is a common complication in patients with chronic kidney disease undergoing hemodialysis. It is associated with inflammation, malnutrition and reduced quality of life. Hemodialysis is the fundamental treatment for people with chronic kidney disease, as it is key to the elimination of toxins from the body. Objective: The objective of this study was to determine the prevalence of probable sarcopenia in patients with chronic kidney disease in the Dialysis Unit of Extremadura (Spain). Material and Methods: This is a descriptive study in which 33 patients with chronic kidney disease receiving hemodialysis were selected as participants in the assessment of functional capacity and physical fitness. The procedure was performed prior to the dialysis session. Socio-demographic, clinical and physical variables were assessed. The assessment of probable sarcopenia was carried out using manual grip strength test (dynamometry), physical performance (4-meter walk test) and phase angle (PhA) (single frequency 50 Hz bioimpedance). The Charlson Comorbidity Index (CCI) was used to determine the severity of chronic disease and its impact, and analytical variables such as albumin, C-reactive protein (CRP), Neutrophil/Lymphocyte Index (NLI), Lymphocyte–Platelet Index (LPI) and total protein (TP), among others, were also included. Results: The prevalence of probable sarcopenia was 93.9% according to the criteria for muscle strength and physical performance (EWGSOP2). PhA showed statistically significant differences between the groups with and without sarcopenia (p = 0.039), suggesting its usefulness as a nutritional marker. No statistically significant differences were found between sarcopenia and age, albumin, Neutrophil/Lymphocyte Index or C-reactive protein (p > 0.05). Conclusions: There is a high prevalence of probable sarcopenia, associated with decreased handgrip strength and gait speed in patients with chronic kidney disease in hemodialysis. In addition, PhA stands out as an influential factor in the development of sarcopenia. Full article

Background: Breast cancer-related lymphedema (BCRL) is one of the most debilitating long-term morbidities after axillary lymph node dissection (ALND), severely impairing quality of life through reduced mobility, independence, and chronic burden, especially in older women. Axillary reverse mapping (ARM) aims to preserve upper extremity lymphatics while maintaining oncologic safety. Evidence in older adult populations with long-term follow-up remains limited. Methods: This retrospective cohort study included 138 female patients (median age 72.5 years) undergoing ALND for invasive breast cancer between January 2018 and January 2024. Patients were divided into ARM (n = 72) and non-ARM (n = 66) groups. BCRL was graded 0–3 according to adapted International Society of Lymphology (ISL) criteria (2013 consensus document). Assessments were performed preoperatively and at 3, 6, 12, 24, 36, 48, and 60 months using blinded circumference measurements and bioimpedance spectroscopy. Results: Baseline characteristics were comparable. Mean follow-up was 46.5 ± 8.8 months. Clinically relevant BCRL (Grades 2–3) was dramatically lower in the ARM group (18.1% vs. 60.6%, p < 0.0001), while subclinical changes (Grade 1) were similar (31.9% vs. 27.3%, p = 0.55). Kaplan–Meier analysis showed significantly better clinically relevant lymphedema-free survival with ARM (log-rank p = 0.00019), with curve separation after 30–40 months—indicating a sustained long-term benefit for quality of life in this frail population. Recurrence rates were comparable (8.3% vs. 10.6%, p = 0.776). Multivariable Cox regression confirmed ARM as an independent protective factor (adjusted HR 0.22, 95% CI 0.11–0.44, p < 0.0001). Conclusions: In older women with breast cancer, ARM significantly reduces clinically relevant lymphedema—a major determinant of long-term quality of life—without compromising oncologic safety. These findings support the routine consideration of ARM during ALND to preserve upper-extremity function, mobility, and independence in this vulnerable population, thereby balancing aggressive oncologic treatment with enhanced long-term quality of life and reduced treatment-related morbidity. Full article

Background and Objectives: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and is frequently associated with multiple comorbidities. Bioelectrical impedance analysis (BIA) provides additional information on body composition and may contribute to the multidimensional assessment of patients with COPD. This study aimed to explore the relationship between BIA-derived parameters and clinical characteristics in hospitalized patients with COPD. Materials and Methods: A cross-sectional analysis of baseline data from a prospective cohort was conducted. A total of 72 hospitalized patients with COPD were included, according to predefined inclusion and exclusion criteria. All patients underwent multifrequency BIA using the InBody 380 device. Sociodemographic, clinical, and paraclinical data were collected and analyzed in relation to BIA-derived parameters. Results: Among the bioimpedance-derived parameters, phase angle (PhA) showed a significant correlation with clinical indices of disease severity, including the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index and the modified Medical Research Council (mMRC) dyspnea scale. Hydration-related parameters reflecting extracellular fluid distribution were associated with the presence of heart failure as a comorbidity. In addition, the evaluation of body fat using bioimpedance identified a higher number of patients with excess body fat compared with obesity defined according to the classical body mass index–based criteria. Conclusions: BIA may provide clinically relevant information on body composition and fluid distribution in patients with COPD. These findings support the potential role of BIA as a complementary tool in the multidimensional evaluation of multimorbid patients with COPD, although further studies are needed to clarify its prognostic value and clinical applicability. Full article

Background and Objectives: Burnout syndrome is a major challenge among healthcare workers, affecting both mental and physical health. Although stress may influence physiological systems, this study does not directly assess biological mechanisms, and interpretations should remain associative. Stress-related associations may be reflected in body composition, but objective data are limited. This study aims to assess the associations between burnout, body composition, and quality of life in medical staff, using bioimpedance as the main tool. Material and methods: The cross-sectional study included 95 medical staff (36 resident doctors, 13 specialists/consultants, 31 nurses, 15 nursing assistants), 75.8% women, mean age 38 ± 10 years, conducted in the medical and surgical departments of Dr. C.I. Parhon Clinical Hospital, Iași, between January and March 2024. Burnout was assessed using the Maslach Burnout Inventory; quality of life was evaluated with SF-12; body composition was measured by bioimpedance (BMI, muscle mass, fat mass, bone mass, hydration, basal metabolism, metabolic age). Statistical analyses included ANOVA, Kruskal–Wallis, and Spearman correlations. Results: Resident physicians had higher muscle, bone mass and basal metabolism, with lower adipose tissue compared to other categories (p < 0.05). Total burnout and exhaustion were positively correlated with muscle mass (r = 0.247, p = 0.016), bone mass (r = 0.219, p = 0.033), basal metabolism (r = 0.219, p = 0.033) and negatively with QoLM (r = −0.315, p = 0.002). Other body variables, including BMI, total adipose tissue, and water level, showed no significant correlations. These associations may be influenced by age, sex, and professional category and do not imply causality. Conclusions: Age, profession, and work seniority are associated with burnout and specific changes in body composition. However, these findings are correlational, and bioimpedance-derived parameters do not reflect direct biological stress mechanisms. Full article

Accurate dry weight assessment is crucial for hemodialysis (HD) fluid management, yet traditional clinical methods often lack precision. A significant scientific gap exists in the availability of a standardized multimodal framework for integrating objective tools, leaving clinicians without clear guidance on combining results from multiple devices. To address this gap, this narrative review provides a qualitative clinical synthesis of bioimpedance spectroscopy (BIS), lung ultrasound (LUS), and inferior vena cava diameter (IVCD). A structured literature search was conducted across PubMed, Scopus, and CINAHL for English-language studies published between 2012 and 2024. Studies focusing on dry weight assessment using these tools in adult HD patients were included, and findings from 22 core studies were synthesized narratively. BIS and LUS are valuable tools for identifying fluid overload. BIS assesses systemic fluid distribution across compartments, whereas LUS allows non-invasive detection of extravascular lung water. In contrast, IVCD primarily reflects intravascular volume status. While the integrated use of these tools shows potential clinical utility, individual methods, particularly IVCD, require further validation owing to interpatient variability. A multimodal approach that integrates these objective methods with clinical judgment offers a comprehensive evaluation of dry weight. Integrating these assessment strategies may improve outcomes and decision-making in nephrology care. Full article

Background: Changes in body composition, such as decreased muscle mass and increased adipose tissue, are significant in older adults, impacting health, functional capacity, and increasing the risk of metabolic diseases, functional decline, and frailty. Bioelectrical Impedance Analysis (BIA) is a non-invasive tool for assessing body composition, including fat-free mass (FFM), skeletal muscle mass (SMM), and fluid distribution (e.g., ECW/TBW ratio). Complementing BIA, the Mini Nutritional Assessment (MNA) serves as a validated tool for identifying malnutrition risk in the elderly. This study aimed to understand the correlation between BIA-derived parameters, MNA scores and clinical outcomes. Methods: This cross-sectional study involved 195 older adults (mean age 72.8 ± 5.4 years), divided into two groups based on body composition profiles determined by cluster analysis. Data collected included demographics, comprehensive BIA parameters (BMI, fat mass, FFM, SMM, ECW/TBW, phase angle), MNA scores, self-assessed health, chronic disease prevalence, frailty index (TFI), and functional limitations (EQ-5D). Statistical analyses included descriptive statistics, t-tests/ANOVA, chi-square tests, Pearson’s/Spearman’s correlations, point-biserial correlations, regression analyses, and ROC curve analysis to compare groups, explore variable relationships, and assess predictive abilities for malnutrition risk. Results: The first group had significantly higher BMI, AFM (AFM), FFM, and SMM, but a lower ECW/TBW ratio compared to Group 2 (N = 115), which was predominantly female and had higher frailty scores. MNA scores showed significant positive correlations with FFM (rho = 0.165, p = 0.021) and SMM (rho = 0.182, p = 0.011), and a negative correlation with ECW/TBW (rho = −0.188, p = 0.008). Higher adiposity (BMI, fat mass) correlated positively with arterial hypertension and obesity. Lower FFM and SMM were negatively correlated with gastroesophageal reflux disease. Skeletal muscle mass (AUC = 0.634, cut-off ≤ 17.3 kg) and ECW/TBW ratio (AUC = 0.626, cut-off ≥ 49.7%) showed modest discriminatory capacity to identify malnutrition risk. Individuals at risk of malnutrition reported greater functional limitations and lower self-assessed health. Numerous BIA parameters, including segmental muscle mass, total body water, phase angle, and impedance values, significantly correlated with MNA scores. Conclusions: The study highlights the importance of body composition analysis, particularly BIA, in correlation with MNA, for assessing nutritional status, functional limitations, and chronic disease associations in older adults. Integrating BIA and MNA into geriatric assessments provides a complementary profile of nutritional and functional vulnerability. Full article

Background/Objectives: Malnutrition and altered body composition are frequent in chronic heart failure (HF) and are associated with worse functional status and prognosis. Bioelectrical impedance analysis (BIA) is increasingly used in nutritional assessment, although its interpretation may be confounded by fluid overload. This study aimed to evaluate the association between BIA-derived parameters and clinical and biochemical markers of disease severity in ambulatory patients with chronic heart failure. Methods: This cross-sectional study included adult outpatients with chronic HF consecutively assessed in a specialised HF unit. Nutritional evaluation comprised anthropometry, handgrip strength, rectus femoris muscle ultrasound and BIA. Phase angle (PA) and hydration-related parameters were analysed in relation to New York Heart Association (NYHA) functional class and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. Multivariable regression models adjusted for relevant clinical and BIA variables were applied. Results: A total of 115 patients were included (mean age 68.2 ± 12.6 years; 71.3% men). Mean PA was 4.6 ± 1.1°. Lower PA was independently associated with greater dyspnoea severity (p = 0.026) and higher NT-proBNP concentrations (p = 0.014). Higher total body water was positively associated with symptom burden (p = 0.013) and NT-proBNP levels (p < 0.001) and showed good discriminatory performance for identifying patients in the highest NT-proBNP quartile. Conclusions: In ambulatory patients with chronic HF, BIA-derived parameters reflecting cellular integrity and hydration status are independently associated with clinical and biochemical markers of disease severity. BIA may provide complementary information in nutritional assessment, although hydration-related confounding should be carefully considered. Future longitudinal studies should determine whether these bioimpedance-derived parameters can improve risk stratification and nutritional assessment in chronic heart failure. Full article

Peripheral nerve injuries pose a significant clinical challenge due to the limited self-repair capacity and the complexity of neural tissue architecture. Tissue engineering strategies applied to the peripheral nerve system aim to restore functional nerve constructs by combining scaffolds, cells, and biochemical cues to recreate the native microenvironment. This work aimed to propose the electrical conductivity as a functional readout of structural and biological remodeling in engineered peripheral nerve scaffolds, along with functional and molecular evaluations. To this end, bioimpedance measurements were combined with equivalent circuit modeling to track state-dependent changes across different levels of tissue organization. Murine sciatic nerves were decellularized and recellularized with neural populations to generate engineered constructs, and their electrical properties were assessed using broadband bioimpedance spectroscopy. Distinct impedance profiles were observed across control, decellularized, and recellularized samples, reflecting structural and functional changes associated with cell removal and repopulation. Furthermore, a multilayer series RC circuit model was implemented to accurately reproduce the measured spectra, enabling the extraction of layer-specific electrical parameters. Analysis of these parameters revealed that decellularization reduces compartmental resistances and increases inter-layer coupling, whereas recellularization restores outer-layer resistances and reduces coupling, consistent with functional tissue organization. Overall, the results demonstrate that bioimpedance provides a readout of the scaffold biological state and cellular integration, and that equivalent circuit modeling offers a quantitative framework to link structural remodeling to electrical function in engineered peripheral nerve tissues. Full article

Electrical Impedance Tomography (EIT) represents a promising and non-invasive technique for the characterisation of biological tissues, but its diagnostic performance strongly depends on the electrode configuration, system geometry, and electronic acquisition strategies. In this work, a three-dimensional model based on the Finite Element Method (FEM) is developed to investigate the detectability of epithelial neoplasms through optimised electrode excitation schemes. The adjacent and opposite configurations are systematically compared in terms of impedance contrast, spatial sensitivity, and neoplastic inclusion localisation capability. The simulations were implemented using an open-source finite element solver with heterogeneous multilayer tissue models. The results show that the configuration with opposite electrodes significantly improves impedance contrast and sensitivity in three-dimensional models, allowing for better detection of localised conductivity anomalies. The proposed approach contributes to the design of optimised EIT electronic systems for early and non-invasive screening applications of epithelial cancer. Full article

Background and Objectives: Weight gain during winter holidays has been reported in several studies, but most of them focus on short-term changes and rely primarily on body weight or BMI. This study investigates if body composition alterations associated with winter holiday period persist over a one-year follow-up in a Romanian adult population. Materials and Methods: This prospective longitudinal observational study included three assessment points: before the winter holidays (T1), immediately after the holidays (T2), and one year later (T3). Bioelectrical impedance analysis was used to obtain body composition parameters. A total of 120 participants completed all three assessments and were included in the longitudinal analysis. Results: Body weight and visceral fat area increased modestly yet significantly between T1 and T2. At the one-year follow-up, values remained similar to those observed immediately after the holiday period, suggesting persistence at group level (body weight: 68.25 → 69.40 → 69.45 kg and visceral fat area: 98.49 → 100.54 → 101.42 cm²). The net change observed during the holiday period was similar in magnitude to the overall annual difference. Changes in body weight were significantly associated with changes in visceral fat both during the holiday period and across the entire follow-up. Conclusions: Modest increases in body weight and visceral fat observed during the winter holidays were still present at one year. These findings suggest that short seasonal periods may contribute to overall annual changes in body weight and fat distribution. Full article

Sarcopenia is characterized by the progressive loss of muscle mass and function, and it represents a significant and prevalent condition in patients undergoing peritoneal dialysis (PD). However, limited research has been conducted to document techniques for the early detection of sarcopenia in adult PD patients. This review addresses the pathophysiology, prognostic implications, and various assessment techniques for sarcopenia, including creatinine kinetics, anthropometry, imaging techniques (computed tomography, magnetic resonance imaging, and ultrasound sonography), bioimpedance spectrometry, and the modified creatinine index. Each of these techniques presents unique strengths and limitations, necessitating careful consideration of the most appropriate assessment method based on specific clinical conditions. By synthesizing current knowledge, this review aims to evaluate the strengths and limitations of available muscle-assessment techniques and assist in the development of improved diagnostic strategies for sarcopenic adult PD patients. Full article

The export of Hass avocado (Persea americana Mill.) from Colombia requires accurate determination of harvest maturity, currently assessed through destructive dry matter (DM) measurements that are wasteful and limited in throughput. The objective of the article is to propose a low-cost, non-destructive approach to determine the maturity of the Hass avocado crop based on machine learning techniques. The approach consists of a low-cost, non-invasive bioimpedance spectroscopy system operating in the 1–10 kHz range, featuring a custom Analog Front End (AFE) and a tetrapolar surface probe to mitigate skin contact resistance, which collects data for predictive models of avocado maturity. To evaluate the quality of the approach, a longitudinal field study (n = 100) was conducted in a commercial orchard in Cundinamarca, Colombia, tracking complex impedance features—Magnitude, Phase Angle, Resistance, and Reactance—of tagged fruits over 8 weeks across four measurement timepoints. The predictive performance of a classical chemometric model (PLS-DA), non-linear classifiers (SVM, Random Forest), and a temporal Deep Learning (LSTM) architecture was compared using a Stratified Group K-Fold Cross-Validation scheme to prevent data leakage across fruits from the same tree. The 4-electrode configuration successfully isolated mesocarp impedance, identifying the 5–7.2 kHz band as the most sensitive to physiological maturation. In turn, the LSTM model achieved a mean accuracy of 92.0% and an AUC of 0.94, outperforming the other models by 4.0% in mean accuracy. The results demonstrate that modeling the temporal trajectory of impedance, rather than single-point measurements, improves harvest maturity classification in Hass avocados, providing a scalable, low-cost alternative to destructive testing. Full article

Background/Objectives: It is often reported in the literature that the prevalence of obesity is high in individuals with Down Syndrome (DS). This study aims to assess how lifestyle factors—diet quality, nutrient intake or physical activity—contribute to weight gain. Methods: 230 males/females with DS, aged 12–45 years, were recruited across three geographically independent sites. A total of 185 participants were considered for this analysis and classified into normal-weight, overweight, and obese categories. Diet quality and nutrient intake were calculated using country-specific FFQs. Physical activity was assessed with the Minnesota Leisure Time Activity Questionnaire. Body composition measures were obtained with a bioimpedance scale. Results: The study corroborates a higher prevalence (%) of overweight/obesity in our DS cohort compared to the general population. Higher BMIs were significantly correlated with older age (p < 0.001), lower physical activity (p < 0.05), higher parental BMIs (p < 0.001, mother’s BMI; p < 0.05, father’s BMI), and increased adiposity indicators. Excess body weight showed an inverse association only with protein intake (p < 0.001). No significant differences emerged in total caloric or other macronutrients intake across BMI categories. However, notable differences in dietary patterns were observed among the three countries, reflecting cultural influences. A smaller exploratory sub-study suggested a potential relationship between higher IQ scores and better diet quality (p < 0.05). Conclusions: These findings provide new insights into contributors to overweight/obesity in DS people, indicating an influence of age, physical activity, familial factors, and body composition. Higher protein intake and culturally adapted lifestyle interventions may contribute to improving weight-related outcomes. Full article