Bioimpedance

Introduction:This review article shows the state of the art of different techniques for monitoring joint injuries. This work is the product of the research project "Viability of electrical impedance tomography for the monitoring of joint injuries", which took place at the University of Cauca during the period 2018-2019. Aim:Identify non-invasive bio-image methods that are used in the evaluation of joint diseases. Methodology: Selection and review of papers related to the evaluation of joint injuries using non-invasive bio-image technologies using systematic mapping.  Results: Magnetic resonance and computed tomography systems make up the non-invasive methods of greater reliability and application in the evaluation of joint injuries. Similarly, some studies show good results from other methods such as systems based on bio-impedance when monitoring the deterioration of joint cartilage. However, electrical impedance tomography (EIT) devices have not yet been widely studied in...

Objetivos: identificar a frequencia de complicacoes pos-extubacao em recem-nascidos em uso de ventilacao mecânica internados em unidade de terapia intensiva neonatal e conhecer fatores de risco associados as complicacoes identificadas. Metodos: estudo observacional, analitico, cujos dados foram colhidos no periodo de junho de 2017 a abril de 2018 em prontuarios de recem-nascidos em uma unidade de terapia intensiva neonatal desde o dia da extubacao ate sete dias apos a retirada da ventilacao mecânica. Resultados: A amostra foi constituida por 158 neonatos. A extubacao foi programada em 114 (72,15%) pacientes e nos demais aconteceu acidentalmente. As complicacoes ocorreram em 112 (70,89%) pacientes, sendo as mais frequentes: necessidade de reintubacao (35,44%), apneia (17,72%), queda de saturacao (17,72%), infeccao (16,46%), estridor laringeo (15,82) e lesao de vias aereas superiores (15,82%). Os fatores de risco encontrados foram: prematuridade, baixa idade gestacional, baixo peso ao...

Objective: the objective of this study was to evaluate lymphedema reduction in lower limbs using grosgrain socks (inelastic) as an isolated form of treatment. Method: 13 consecutive patients with lymphedema in the lower limbs treated with grosgrain socks were evaluated in prospective clinical assays for volumetry in the Godoy Clinic in 2012. There were five male and eight female patients, with ages ranging between 26 and 72 years and average of 49.0 years. The inclusion criterion was presenting grade II lymphedema in the lower limbs regardless of the cause; patients with a history of allergies and intolerance to containment mechanisms, infectious processes, joint immobility, and other causes that could interfere with the edema were excluded. The treatment used grosgrain socks, which are inelastic, custom made and closed through eyelets that allow adjustment by the patient. The volumetric technique was used to measure water-offset at the start and all follow-ups. The paired t-test was used for the statistical analysis considering a 5% alpha error. Results: the study was approved by the Research Ethics Committee. A significant reduction was detected in treated patients, two-tailed paired t-test with p.

Anotace: Příspěvek se zabývá využitím numerického modelování nehomogenních materiálových vzorků k ověření správnosti výsledků MRI. Pro účely studia deformací MR obrazů magnetického pole v okolí měřených dia-paramagnetických vzorků vlivem susceptibility heterogenních materiálů (objektů) vybrána jednoduchá konfigurace vzorku a byly porovnány numericky modelované řezy s experimentálním měřicím průběhem magnetického pole měřeného MR technikou gradientního echa.

Huntington's disease (HD) is a rare, incurable neurodegenerative disorder where fast and non-invasive diagnosis targeting patients' condition plays a crucial role. In modern medicine, various scientific areas are being combined, such as computing, medicine and biomedical engineering. This survey is focused on the most recent image processing methods applied not only for the purpose of diagnosing HD but also for the assessment of its progression severity, in order to contribute to the effort to prolong life of and to improve its quality.

It is hereby presented a new approach to monitor restenosis in arteries fitted with a stent during an angioplasty. The growth of neointimal tissue is followed up by measuring its bioimpedance with Electrical Impedance Spectroscopy (EIS). Besides, a mathematical model is derived to analytically describe the neointima’s histological composition from its bioimpedance. The model is validated by finite-element analysis (FEA) with COMSOL Multiphysics®. Satisfactory correlation between the analytical model and the FEA simulation is achieved for most of the characterization range, detecting some deviations introduced by the thin "double layer" that separates the neointima and the blood. It is shown how to apply conformal transformations to obtain bioimpedance models for stack-layered tissues over coplanar electrodes. Particularly, this is applied to characterize the neointima in real-time. This technique is either suitable as a main mechanism of restenosis follow-up or it can be c...

This paper proposes a new yet efficient method allowing a significant improvement in the on-line analysis of biological cell growing and evolution. The procedure is based on an empirical-mathematical approach for calibration and fitting of any cell-electrode electrical model. It is valid and can be extrapolated for any type of cellular line used in electrical cell-substrate impedance spectroscopy (ECIS) tests. Parameters of the bioimpedance model, acquired from ECIS experiments, vary for each cell line, which makes obtaining results difficult and-to some extent-renders them inaccurate. We propose a fitting method based on the cell line initial characterization, and carry out subsequent experiments with the same line to approach the percentage of well filling and the cell density (or cell number in the well). To perform our calibration technique, the so-called oscillation-based test (OBT) approach is employed for each cell density. Calibration results are validated by performing othe...

A smart sensor system for cell culture real-time supervision is proposed, allowing for a significant reduction in human effort applied to this type of assay. The approach converts the cell culture under test into a suitable "biological" oscillator. The system enables the remote acquisition and management of the "biological" oscillation signals through a secure web interface. The indirectly observed biological properties are cell growth and cell number, which are straightforwardly related to the measured bio-oscillation signal parameters, i.e., frequency and amplitude. The sensor extracts the information without complex circuitry for acquisition and measurement, taking advantage of the microcontroller features. A discrete prototype for sensing and remote monitoring is presented along with the experimental results obtained from the performed measurements, achieving the expected performance and outcomes.

Objective: Bioimpedance spectroscopy (BIS) can be used to determine hypervolemia and malnutrition in chronic hemodialysis (HD) patients. In this prospective observational study, we investigated the survival predictability of impedance ratio (IR) calculated by BIS in HD patients (Clinical Trials Gov Identifier: NCT01468363). Materials and Methods: A total of 430 chronic HD patients, out of 500 prevalent chronic HD patients from the city of Zonguldak who met the inclusion criteria, were included in the study. With a mean follow-up of 32.2±14.4 months, BIS was performed in all patients. The IR percentage (IR%) was calculated by dividing the resistance values using the 200 kHz and 5 kHz impulses. Student's t-test, Cox regression analysis, and Kaplan-Meier survival analysis were performed, and a p<0.05 was accepted as statistically significant. Results: The mean age of 430 patients was 59±15 (10-92) years, and 54% of patients were male. By the end of the study, 125 (29%) patients died. Diabetes mellitus was observed in 46% of patients. Sixty-seven percent of patients used erythropoietin, and 41% used diuretics. The mean systolic blood pressure of patients before the dyalisis was 133±26 mmHg, and diastolic blood pressure was 79±12 mmHg. The IR values ranged between 73.2% and 94.1%. A multi-regression analysis that used the IR and included diabetes mellitus, age, gender, and albumin and hemoglobin levels showed that the mortality risk increased 16% (p<0.001). Evaluation using the quartiles showed decreased survival. Survival in the first quartile group was 42.8 months compared to 30.6 months in the last quartile group. Conclusion: The IR calculated using BIS data is a useful tool that can be employed to predict the survival in chronic HD patients. An early awareness of this increased mortality risk is important in terms of a close follow-up and appropriate treatment of these patients.

OBJECTIVE: Hypervolemia and malnutrition are often undiagnosed risk factors for hemodialysis (HD). Our aim was to investigate the long-term effects of hypervolemia and malnutrition evaluated by bioimpedance spectroscopy (BIS) on survival. (Clinical Trials. Gov Identifier: NCT01468363). MATERIAL and METHODS: A total of 431 Prevalent HD patients were followed for 32.2±14.4 months. The patients underwent BIS measurement, a medical history was obtained, and routine tests were analyzed at the baseline and at the end of the study. Hospitalizations and complications of HD were recorded. RESULTS: The mean age was 59.4±14.6 (10-92) years with a total of 431 (53.6% males) patients of which 125 died. The percentage of diabetics was 47%, erythropoietin use 67%, and diuretic use 40%. Predialysis systolic blood pressure (BP) was 133.4±25.8 and diastolic BP 79.2±12.4 mm Hg. The rate of diabetes, and the number of hospitalizations and blood transfusions were higher in the patients who died. Diastolic BP as a clinical hypervolemia finding, BIS hypervolemia indicator of over hydration (OH), and extracellular water (ECW) were all increased, and fat tissue index as a malnutrition finding was decreased in patients who died. There were significant rates of anemia and hypoalbuminemia in this group as well. The cumulative survival was lower in hypervolemic patients as assessed by relative hydration status OH/ECW. CONCLUSION: Hypervolemia and malnutrition are the long-term mortality indicators in hemodialysis. Early diagnosis and treatment is important. Clinical findings may not be sufficient and laboratory and BIS methods can be used for diagnosis.

Fluid overload is associated with adverse outcomes in hemodialysis (HD) patients. Two bedside methods are increasingly utilized to evaluate objectively fluid status-bioimpedance and lung ultrasonography, but there is no available direct, head-to-head comparison of their prognostic significance. Importantly, their predictive abilities have never been tested in a HD population, alongside those of a classic model that also incorporates established echocardiographic parameters of increased mortality risk. Between 26 May 2011 and 26 October 2012, we included in the study 173 patients undergoing chronic HD treatment for at least 3 months in a single dialysis unit. Relative fluid overload (RFO) and B-lines score (BLS) were used as candidate predictors. From Cox survival analysis we evaluated the increase in the predictive abilities for allcause mortality of adding continuous RFO or BLS to a model including conventional predictors. 31 patients (17.9 %) died during a median follow-up of 21.3 (interquartile range 19.9-30.3) months. All Cox models showed good calibration. The C statistic for the all-cause mortality prediction increased significantly when the RFO was included into the baseline model (DC statistics 0.058 95 %CI = 0.003-0.114), but not when the BLS was included into the baseline model. Only the model that incorporated RFO showed significantly better risk reclassification abilities than the baseline model (IDI = 3.6 % and continuous NRI = 24.8 %). Fluid overload, as assessed by bioimpedance, and not by lung ultrasonography, improves risk prediction for death, beyond classical and echocardiographic-based risk prediction scores/parameters.

Recent advancements in bioimpedance technology have demonstrated significant promise in the application of cardiac health monitoring. This research explores the design and development of a forearm-based wearable bioimpedance device for non-invasive measurement of heart rate and respiratory rate at an accuracy level comparable to medical-grade monitors. It utilizes a tetrapolar electrode configuration to analyze bioimpedance changes in the radial artery due to blood flow.

An ongoing aspect of this work involves the preliminary development of an embedded framework intended to integrate signal generation, acquisition, and processing within the device to achieve compact and efficient system design, anticipated to contribute to its overall performance. However, current efforts focus on addressing the technical challenges inherent in such integration, including its impact on improving signal fidelity and device usability.

Bioimpedance-based wearables have further potential in correlating the resulting signals to several complex cardiac diseases such as COPD, Asthma and CHF. Unlike photoplethysmography (PPG) based systems, bioimpedance can directly measure multidimensional physiological data relevant to cardiac health including fluid balance, tissue composition and thoracic fluid content. These measurements are less susceptible to external factors like motion artifacts and skin pigmentation, offering a consistent and reliable method for long-term monitoring in diverse populations and non-clinical settings. This capability to correlate changes in bioimpedance with cardiac functions presents avenues for early detection and nuanced monitoring of complex cardiac conditions, potentially offering a more comprehensive understanding of the patient's cardiovascular health. Additionally, the integration of advanced bioimpedance monitoring into wearable devices also allows for personalized healthcare and remote patient monitoring, thus promising enhanced diagnostic accuracy and patient convenience.

This research exemplifies the commitment to pushing the boundaries of wearable health technology, while acknowledging the complexity of developing a fully integrated, miniaturized solution. It also reviews the evolution and theoretical basis of bioimpedance technology in cardiology, underscoring the innovative potential of the four-electrode forearm wearable system in transforming cardiac health monitoring.

A smart sensor system for cell culture real-time supervision is proposed, allowing for a significant reduction in human effort applied to this type of assay. The approach converts the cell culture under test into a suitable &quot;biological&quot; oscillator. The system enables the remote acquisition and management of the &quot;biological&quot; oscillation signals through a secure web interface. The indirectly observed biological properties are cell growth and cell number, which are straightforwardly related to the measured bio-oscillation signal parameters, i.e., frequency and amplitude. The sensor extracts the information without complex circuitry for acquisition and measurement, taking advantage of the microcontroller features. A discrete prototype for sensing and remote monitoring is presented along with the experimental results obtained from the performed measurements, achieving the expected performance and outcomes.

Adiunkt w Zakładzie Metrologii Wielkości Geometrycznych Instytutu Zaawansowanych Technologii Wytwarzania (dawniej IOS) w Krakowie. Studia wyższe ukończyła na Wydziale Inżynierii Mechanicznej i Robotyki AGH w Krakowie. Stopień doktorski uzyskała na Wydziale Automatyki, Elektroniki i Informatyki Politechniki Śląskiej w Gliwicach. Interesuje się głównie współrzędnościową techniką pomiarową i zagadnieniami oceny wyników pomiarów.

Resumo-O objetivo do presente estudo foi comparar medidas antropométricas (massa corporal, estatura e percentual de gordura) e a amplitude de movimento (ADM) de dorsiflexão e plantiflexão entre três diferentes grupos: bailarinas clássicas (n=14), jogadoras de voleibol (n=22) e mulheres fisicamente ativas (n=13). Assumiuse que diferentes demandas funcionais deveriam produzir alterações nas medidas antropométricas e de ADM entre os três grupos. A massa corporal e a estatura foram maiores nas atletas de voleibol (66,42 ± 5,8 kg; 174,77 ± 5,6 cm), seguidas das mulheres fisicamente ativas (59,93 ± 10,3 kg; 164 ± 7,5 cm) e das bailarinas clássicas (49,25 ± 4,5 kg; 157,03 ± 3,6 cm), respectivamente (p<0,05). O percentual de gordura foi maior nas mulheres ativas (30,67 ± 4,6%) quando comparadas aos outros dois grupos, que foram semelhantes entre si (jogadoras de voleibol = 24,93 ± 4,1%; bailarinas = 21,94 ± 4,3%, respectivamente). Os três grupos apresentaram semelhante ADM entre os lados direito e esquerdo e para a amplitude de movimento ativa de dorsiflexão. Entretanto, para a plantiflexão a amplitude de movimento ativa foi maior nas bailarinas (~83°), seguidas das mulheres fisicamente ativas (~68°) e, por fim, pelas jogadoras de voleibol que apresentaram a menor amplitude de flexão plantar (~60°). As diferentes demandas impostas pelas três distintas atividades parecem ser responsáveis pelas mudanças em algumas variáveis antropométricas e na ADM da articulação do tornozelo. Palavras-chave: Bailarinas; Jogadoras de voleibol; Bioimpedância; Variáveis antropométricas.

Streszczenie. W pracy zawarto opis problemu weryfikacji czasowych protokołów zabezpieczających przy uwzględnieniu opóźnień w sieci. Za pomocą specjalnie skonstruowanego modelu formalnego, który stał się podstawą do implementacji narzędzia, możliwe jest obliczanie czasu poprawnego wykonania protokołu. Narzędzie umożliwia przeprowadzenie badań czasowych protokołów zabezpieczających, w tym przeprowadzenie symulacji. Słowa kluczowe: analiza czasów, protokoły zabezpieczające, symulacje ANALYSIS AND SIMULATIONS OF TIMED SECURITY PROTOCOLS Summary. This paper contains a description of the problem of timed security protocols verification, taking into account delays in the network. Using a specially constructed formal model, which became the basis for the implementation of the special tool, it is possible to calculate the correct time of execution protocol. The tool enables testing timed security protocols, including simulations.

Evaluation of wound status is typically based on means which require the removal of dressings. These procedures are often also subjective and prone to inter-observer bias. To overcome aforementioned issues a bioimpedance measurement-based method and measurement system has been developed to evaluate the state of wound healing. The measurement system incorporated a purpose-built bioimpedance device, a measurement software and a screen-printed electrode array. The feasibility and the performance of the system and method were assessed in an open non-randomized follow-up study of seven venous ulcers. Healing of ulcers was monitored until the complete re-epithelialization was achieved. The duration of follow-up was from 19 to 106 days (mean 55.8 ± 25.2 days). A variable designated as the Wound Status Index (WSI), derived from the bioimpedance data, was used for describing the state of wound healing. The wound surface area was measured using acetate tracing for the reference. A strong correlation was found between the WSI and the acetate tracing data, r(93) =-0.84, p < 0.001. The results indicate that the bioimpedance measurement-based method is a promising quantitative tool for the evaluation of the status of venous ulcers.

Breathing parameter extraction from localized thoracic bioz 148 Cardiac anomalies diagnosis using bioimpedance method 149 high frequency sensors in single use culture technology 150 Impedance measurements to determine hairy root biomass 151 EIS characterisation of hydrodynamics in porous bilayers 153 Characterization of graphene oxide coated gold electrodes 155 Can impedance cardiography detect pulmonary edema? 156 The Russian Bioimpedance Megabase: current state and results 157 Bioimpedance-in-vivo vs in-vitro ischemic small intestine 158 In-cycle detection of acute myocardial ischemia by fast EIS 159 System for local bioimpedance measurements in heart failure 160 MIS-phase shift vs uS-elastography in breast cancer 162 Bioimpedance phase angle: the Russian reference data 164 Cardiac and respiration signals recording by an MIT system 165 Effects of in vivo muscle injury on muscle impedance in mice 166 Bio impedance system for wearable vital sign monitoring 167 Real-time microcontroller-based mit phase measurement system 168 Mutual capacitance sensors for tissue diagnostics 169 Impedance value differences between knees in female athletes 170 System for nerve stimulation and bioimpedance measurements 171 Comparison between AC & DC exosomatic EDA measuring methods 172 Adaptive algorithm for cardiac period normalization in time 173 Difference sampling in bio-impedance measurement 174 Limitation of signal amplitudes in bioimpedance spectroscopy 175 Stable and precise real-time MIT phase measurement system 176 Resistive component of meat electrical bioimpedance 177 Neural tissue discrimination with machine learning methods 178 Chirp signals in impedance spectroscopy 179 using pacemaker leads for bioimpedance and electromyography 181 EIT-derived stroke volume is impaired by belt displacement 182 Research on heat and cold of resistance by EIS in rose 183 Impedimetric sensing of microbial growth in droplets 184 Tracing of left ventricular DP/DT using icg and bp signals 185 Monitoring of stratum corneum moisture by skin admittance

W artykule autorzy przedstawiają modele szacowania czasow wykonywania sie petli programowych zgodnych z modelem FAN nieposiadającym zalezności lub posiadającym zalezności, ale tylko w ciele petli, ktore wykonywane mogą byc przez centralne jednostki obliczeniowe CPU jak i multiprocesory strumieniowe zwane rdzeniami kart graficznych GPU. Zaprezentowane w niniejszym artykule modele szacowania czasow wykonywania tych petli pozwolą na określanie tego, czy obliczenia w zastanym środowisku obliczeniowym warto wykonywac z uzyciem posiadanego procesora CPU czy korzystniejsze bedzie wykorzystanie do obliczen posiadanej, czesto nowoczesnej, karty graficznej z wydajną jednostką GPU i bardzo szybką pamiecią stosowaną we wspolczesnych kartach graficznych. Wraz z zaprezentowanymi modelami przedstawiono takze testy potwierdzające poprawnośc opracowanych modeli szacowania czasu. Celem powstania tych modeli jest dostarczenie metod przyspieszania dzialania aplikacji realizujących rozne zadania, w tym ...

The rate is assessed as per the body fat percentages (%BF) estimated through anthropometric measurements and manual bioimpedance, according to gender and adiposity rate within the paediatric population. The %BF is assessed by anthropometry using the Slaughter equation for cutaneous skinfolds and manual bioimpedance (Omron model HBF-306INTTM) to 321 students (160 females and 161 males) between 10-18 years. The association degree among the methods was measured using the Pearson correlation coefficient (r). The consistency among methods was analysed through the intra-class correlation coefficient (ICC) and the consistency correlation coefficient of Lin (CCC), grouping the population by gender and adiposity rate. The reference method was the cutaneous skinfolds assessed by the Slaughter equation. Optimum and high adiposity rates were recorded for the studied sample. The r between the bioimpedance and the anthropometry was 0.689, which corresponds to moderate. However, it decreased according to the gender and adiposity rate (females: optimum 0.409 and high 0.610; males: optimum 0.335 and high 0.507). The ICC was 0.668, which also decreased by gender and adiposity rate (females: optimum 0.323 and high 0.578; males: optimum 0.229 and high 0.506). CCC was poor (<0.90) by gender and adiposity rate. The study shows differences for both methods in this age range, which is accentuated by gender and adiposity rate. Therefore, the use of manual bioimpedance as an interchangeable method with the anthropometric measurements in children and adolescents is not suggested as it underestimates the %BF.

The aims of this study were to analyze the usefulness of raw bioelectrical impedance (BI) parameters in assessing water compartments and fluid distribution in athletes. A total of 202 men and 71 female athletes were analyzed. Total body water (TBW) and extracellular water (ECW) were determined by dilution techniques, while intracellular water (ICW) was calculated. Fluid distribution was calculated as the ECW/ICW ratio (E:I). Phase angle (PhA), resistance (R) and reactance (Xc) were obtained through BI spectroscopy using frequency 50kHz. Fat (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry. After adjusting for height, FM, FFM, age and sports category we observed that: PhA predicted ICW (females: β = 1.62, p &lt; 0.01; males: β = 2.70, p &lt; 0.01) and E:I (males and females: β = −0.08; p &lt; 0.01); R explained TBW (females: β = −0.03; p &lt; 0.01; males: β = −0.06; p &lt; 0.01) and ECW (females: β = –0.02, p &lt; 0.01; males: β = −0.03, p &lt; 0.01) and...

It is important for highly active individuals to accurately assess their hydration level. Bioelectrical impedance (BIA) can potentially meet these needs but its validity in active individuals is not well established. We compared whole-body bioimpedance measurements obtained from multi-frequency bioelectrical impedance spectroscopy (BIS, Xitron 4200) at a 50 kHz frequency with those determined by a phase-sensitive single-frequency device (SF-BIA, BIA-101, RJL/Akern Systems) in two populations: active adults and elite athletes. One hundred twenty-six participants, including active males involved in recreational sports (N = 25, 20-39 yr) and elite athletes (females: N = 26, 18-35 yr; males: N = 75, 18-38 yr) participated in this study. Reactance (Xc), Resistance (R), Impedance (Z), and phase angle (PhA) were obtained by BIS and SF-BIA. Small but significant differences (R: -9.91 ± 15.09 Ω; Xc: -0.97 ± 2.56 Ω; Z: -9.96 ± 15.18 Ω; PhA: 0.12 ± 0.2°) were observed between the bioimpedance ...

A novel method for embedded hardware-based parameter estimation of the Cole model of bioimpedance is developed and presented. The model parameters R∞, R1 and C are estimated using the derived set of equations based on measured values of real (R) and imaginary part (X) of bioimpedance, as well as the numerical approximation of the first derivative of quotient R/X with respect to angular frequency. The optimal value for parameter α is estimated using a brute force method. The estimation accuracy of the proposed method is very similar with the relevant work from the existing literature. Moreover, performance evaluation was performed using the MATLAB software installed on a laptop, as well as on the three embedded-hardware platforms (Arduino Mega2560, Raspberry Pi Pico and XIAO SAMD21). Obtained results showed that the used platforms can perform reliable bioimpedance processing with the same accuracy, while Raspberry Pi Pico is the fastest solution with the smallest energy consumption.

objective: To evaluate the clinical outcome of very low birth weight newborns, submitted to high frequency oscillatory ventilation with a strategy of early lung volume optimization. Methods: Descriptive prospective study in a nine-year period, between 1999 January 1st to 2008 January 1st. All the very low birth weight newborns were born in Dr. Alfredo da Costa Maternity, Lisbon, Portugal, were

Accurate predictive tools are key factors for cancer care. Phase angle (PhA) has been proposed as a marker of cellular health, particularly of cell-membrane integrity. Cutoff values have been proposed, including for cancer survivors. This study aimed to assess the usefulness of the proposed PhA cutoff, as a marker of bioelectrical impedance analysis (BIA) assessed health-status, and functional capacity in breast cancer (BC) survivors. This cross-sectional study included 25 women (50.6 ± 8.6 yrs) survivors of BC, divided into two groups according to the PhA reference value of 5.6 • (group 1 [G1]: PhA ≤ 5.6 • [n=13]; group 2 [G2]: PhA > 5.6 • [n=12]) (Gupta et al. 2008). BIA-assessed health status parameters included: extracellular water (ECW), intracellular water (ICW), total body water (TBW), PhA, body mass, fat-free mass, muscle mass, body cell mass (BCM). Four functional tests were performed: 30 s chair-stand test, timed up and go test, ball throw test and 6-minute walking test. Results showed G2 had lower ECW/ICW ratio (p=0.001; ES=1.2), ECW/BCM ratio (p=0.001; ES=3.2) and ECW/TBW ratio (p=0.001; ES=4.8). There was no difference in functional capacity between groups. The results of the present study show that patients with higher PhA values have a higher ICW values and preservation in the ECW/ICW ratio, suggesting it's a better cell membrane quality and integrity. Relation of both PhA and cell membrane integrity with functional capacity warrants further research.

A technique for real-time monitoring of bioimpedances using a Voltage Oscillation (VO) methodology is proposed. The main idea relies on connecting the bio-system in such a way that a suitable electrical oscillator, which only uses a DC power source, is built. Thanks to the employed electrical models, the oscillation parameters can be directly related to the biological test. System simulations show that the impedance values of a tissue, called herein Zx, can be determined by measuring the actual frequency and amplitude of the proposed VO system, being possible to select the frequency range to optimize the system sensitivity.

A sinusoidal voltage wave generator is proposed based on the use of microprocessor digital signals with programmable duty-cycles, with application to real-time Electrical Cell-substrate Impedance Spectroscopy (ECIS) assays in cell cultures. The working principle relies on the time convolution of the programmed microcontroller (µC) digital signals. The expected frequency is easily tuned on the bio-impedance spectroscopy range [100 Hz, 1 MHz] thanks to the µC clock frequency selection. This system has been simulated and tested on the 8 bits µC Arduino™ Uno with ATmega328 version. Results obtained prove that only three digital signals are required to fit the general specification in ECIS experiments, below 1% THD accuracy, and show the appropriateness of the system for the real-time monitoring of this type of biological experiments.

The aim of this work is to present a new circuit for the real-time monitoring the processes of cellular growth and differentiation of skeletal myoblast cell cultures. An impedance spectroscopy Oscillation-Based technique is proposed for the test circuit, converting the biological system into a voltage oscillator, and avoiding the use of very high performance circuitry or equipment. This technique proved to be successful in the monitoring of cell cultures growth levels and could be useful for determining the degree of differentiation achieved, of practical implications in tissue engineering.

As is known, bioimpedance is a measurement method that can be used in medicine to know the volume of a person's urinary bladder. However, this method is not entirely reliable due to the multiple factors that influence its measurement, such as the weight of the person, body fat and even the different skin type of each person. Therefore, this paper proposes a method that combines bioimpedance, hypogastric region temperature and an artificial feedforward neural network, sufficiently capable of determining when to empty the bladder, so that this muscle is not affected by the time exceeded of urine continence, this work is aimed to people who have suffered injuries to their spine, who do not have the ability of feeling when their bladder needs to be emptied. It is also aimed to older adults who begin to have problems with their bladder control, allowing them to improve their quality of life.

El siguiente trabajo presenta una revisión de las propiedades eléctricas de los tejidos biológicos. Los tópicos incluidos en el trabajo son el estudio, caracterización y técnicas de medición. Se aborda el tema de las propiedades de conductividad (σ) y permitividad (ε) eléctrica de los tejidos y los modelos creados para su estimación y aproximación. Se presentan las características de los elementos de medición, ventajas y desventajas de los diferentes métodos creados y sus aplicaciones. Se mencionan algunos de los tipos de señales más utilizadas en cuanto a corriente y frecuencia de aplicación. Finalmente se presentan algunas recomendaciones a tener en cuenta al momento de realizar mediciones in vivo, para disminuir los errores debido a las múltiples fuentes fisiológicas. Esta revisión permitió obtener los lineamientos y condiciones de un trabajo de medición de impedancia de fémur que se encuentra en desarrollo.

profesor Instytutu Informatyki i Elektroniki. Zainteresowania to elektronika, projektowanie i produkcja urządzeń elektronicznych-kalibratory napięć, prądów i mocy, mierniki parametrów sieci, analizatory jakości energii, testery liczników energii i zabezpieczeń oraz automatyzacja pomiarów.

This paper covers a brief review of both the advantages and disadvantages of the implementation of various smoothing filters in the analysis of electroencephalography (EEG) data for the purpose of potential medical diagnostics. The EEG data are very prone to the occurrence of various internal and external artifacts and signal distortions. In this paper, three types of smoothing filters were compared: smooth filter, median filter and Savitzky–Golay filter. The authors of this paper compared those filters and proved their usefulness, as they made the analyzed data more legible for diagnostic purposes. The obtained results were promising, however, the studies on finding perfect filtering methods are still in progress.

The article presents a method of diagnosing the technical conditions of a power amplifier which is used in a sound warning system (SWS). Fire Alarm Systems (FAS) and SWSs are electronic safety systems designed to protect life and health. The FAS is used for effective fire detection, while life-threatening SWSs provide efficient communication of emergency information and evacuation routes via voice. The article presents the problem of diagnosing the technical condition of power amplifiers, which are the essential elements of SWSs. Power amplifiers provide a certain level of undistorted audio (alarm messages) to the speaker set that is arranged in a building supervised by FAS. Keywords: amplifier, audible warning system, working parameters

Background. Technique failure in peritoneal dialysis (PD) can be due to patient-and procedure-related factors. With this analysis, we investigated the association of volume overload at the start and during the early phase of PD and technique failure. Methods. In this observational, international cohort study with longitudinal follow-up of incident PD patients, technique failure was defined as either transfer to haemodialysis or death, and transplantation was considered as a competing risk. We explored parameters at baseline or within the first 6 months and the association with technique failure between 6 and 18 months, using a competing risk model. Results. Out of 1092 patients of the complete cohort, 719 met specific inclusion and exclusion criteria for this analysis. Being volume overloaded, either at baseline or Month 6, or at both time points, was associated with an increased risk of technique failure compared with the patient group that was euvolaemic at both time points. Undergoing treatment at a centre with a high proportion of PD patients was associated with a lower risk of technique failure.

The required frequency range of electrical bioimpedance (EBI) measurements depends on the dielectric properties of the object and covers about three to four decades typically within the kHz to MHz range. The accuracy of fitting of the equivalent circuit-based impedance model with the measurement results depends on the number of frequency components used. In general, the use of more frequencies improves the fitting accuracy but complicates the measurements. However, the fitting accuracy also depends on the signal-to-noise ratio (SNR) of measurement signals. If covering the frequency range with a simultaneous multifrequency excitation, the root mean square values of its frequency components are decreasing when their number increases. It follows that the number of used frequency components has two contradictory effects on the accuracy of estimation of parameters of the equivalent circuit model. This chapter deals with the analysis of typical EBI model-fitting situations and shows how the number of frequency components influences the fitting error. Our research shows that in the case of multifrequency excitation the accuracy of fitting of the typical equivalent circuit-based EBI model may not increase when the number of frequencies is increasing. The results described here could be useful in other implementations of impedance spectroscopy.

Electrical Resistance Tomography (ERT) is a technique employed in the industrial environment that reconstructs images formed by the impedance distributions inside a vessel. The method relies on measures from a data acquisition system, responsible to inject a current inside the vessel and measures the voltage on the boundaries, and sequentially an inverse problem solution. This paper introduces a low-cost design of an acquisition system that can obtain 30 images/s with a signal-to-noise ratio of 57.47 dB and a maximum error of 3.79%. It utilizes a simple RMS-to-DC converter demodulation scheme to provide good accessibility to researchers aimed at investigating flow patterns of multiphase flow applications.

A maioria das técnicas de diagnóstico por imagem para detecção de fraturas ósseas utiliza equipamentos que emitem radiação, que pode ser prejudicial à saúde humana, mesmo em pequenas doses. Sem dúvida, estudos são necessários e novas técnicas que busquem a redução dessas exposições ao raio-x. O objetivo deste artigo é desenvolver um fantoma biológico 3D e investigar a sensibilidade de detecção de ossos, inteiro e fraturado, por meio da espectroscopia de impedância elétrica. Além disso, são investigados os efeitos das diferentes posições dos eletrodos na sensibilidade da técnica de medição. As medições foram realizadas por um espectroscópio de impedância comercial da Zurich Instruments (modelo HF2IS) na faixa de frequência de 1 kHz a 1 MHz. Quatro eletrodos circulares (modelo MELCTEC) foram usados ​​para conectar o fantoma ao HF2IS. O HF2IS foi inicialmente calibrado medindo um resistor de 100 Ω e 1% de precisão. Vetores de calibração de magnitude e fase foram calculados e então usad...

Extensive bioelectrical impedance analysis (BIA) data have the potential of health monitoring and the assessment of health risks at the population level. The importance of BIA data lies in their availability and abundance for many countries. In Russia, mass BIA data are generated by the national network of health centers (HCs). Our aim was to describe the structure and capabilities of the updated HCs’ BIA database. Upon several requests between 2012 and 2020, 369 HCs representing all Federal districts of Russia and 60 out of 85 Federal subjects in them, submitted raw bioimpedance data which were obtained using the same type of BIA instrument, namely ABC-01 ‘Medas’ (SRC Medas, Russia). After application of strict selection criteria, 2,429,977 BIA measurement records were selected that formed the updated 2010-2019 HCs’ database. Various slices of the BIA data are described according to spatiotemporal, demographic and other characteristics. Reference curves of the bioimpedance phase an...