Description of disease Bioelectric impedance analysis. Treatment Bioelectric impedance analysis. Symptoms and causes Bioelectric impedance analysis Prophylaxis Bioelectric impedance analysis
Purpose: To analyze the association between body fluid changes evaluated by bioelectrical impedance vector analysis and dilution techniques over a competitive season in athletes. Methods: A total of 58 athletes of both sexes (men: age 18.7 [4.0] y and women: age 19.2 [6.0] y) engaging in different sports were evaluated at the beginning (pre) and 6 months after (post) the competitive season. Deuterium dilution and bromide dilution were used as the criterion methods to assess total body water (TBW) and extracellular water (ECW), respectively; intracellular water (ICW) was calculated as TBW-ECW. Bioelectrical resistance and reactance were obtained with a phase-sensitive 50-kHz bioelectrical impedance analysis device; bioelectrical impedance vector analysis was applied. Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. The athletes were empirically classified considering TBW change (pre-post, increase or decrease) according to sex. Results: Significant mean vector ...
TY - JOUR. T1 - Bioelectrical impedance analysis. T2 - Implications for clinical practice. AU - Jacobs, Danny O.. PY - 1997/12/1. Y1 - 1997/12/1. N2 - Bioelectrical impedance analysis (BIA) has received significant attention as a means of studying body composition and the relationship of changes in the bodys conductive and other electrical properties to changes in body water or its distribution. The application of this technology to the care of patients with nutritional and metabolic disorders is presently under investigation. In this review, a broad overview of recent literature is provided, after the background and rationale for BIA and factors affecting the accuracy of measurements are reviewed.. AB - Bioelectrical impedance analysis (BIA) has received significant attention as a means of studying body composition and the relationship of changes in the bodys conductive and other electrical properties to changes in body water or its distribution. The application of this technology to the care ...
Drug and bioactive molecule screening based on a bioelectrical impedance cell culture platform Sakthivel Ramasamy,1 Devasier Bennet,1 Sanghyo Kim1,2 1Department of Bionanotechnology, Gachon University, Gyeonggi-Do, Republic of Korea; 2Graduate Gachon Medical Research Institute, Gil Medical Center, Incheon, Republic of Korea Abstract: This review will present a brief discussion on the recent advancements of bioelectrical impedance cell-based biosensors, especially the electric cell-substrate impedance sensing (ECIS) system for screening of various bioactive molecules. The different technical integrations of various chip types, working principles, measurement systems, and applications for drug targeting of molecules in cells are highlighted in this paper. Screening of bioactive molecules based on electric cell-substrate impedance sensing is a trial-and-error process toward the development of therapeutically active agents for drug discovery and therapeutics. In general, bioactive molecule
Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse. Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse.
Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse. Bioelectrical Impedance Analysis (BIA) and Body Composition Analyse.
BACKGROUND: Little information is available on the validity of simple and indirect body-composition methods in non-Western populations. Equations for predicting body composition are population-specific, and body composition differs between blacks and whites. OBJECTIVE: We tested the hypothesis that the validity of equations for predicting total body water (TBW) from bioelectrical impedance analysis measurements is likely to depend on the racial background of the group from which the equations were derived. DESIGN: The hypothesis was tested by comparing, in 36 African women, TBW values measured by deuterium dilution with those predicted by 23 equations developed in white, African American, or African subjects. These cross-validations in our African sample were also compared, whenever possible, with results from other studies in black subjects. RESULTS: Errors in predicting TBW showed acceptable values (1.3-1.9 kg) in all cases, whereas a large range of bias (0.2-6.1 kg) was observed ind
This thesis work covered the fabrication and characterisation of impedance sensors for biological applications aiming in particular to the cytotoxicity monitoring of cultured cells exposed to different kind of chemical compounds and drugs and to the identification of different types of biological tissue (fat, muscles, nerves) using a sensor fabricated on the tip of a commercially available needle during peripheral nerve block procedures. Gold impedance electrodes have been successfully fabricated for impedance measurement on cells cultured on the electrode surface which was modified with the fabrication of gold nanopillars. These nanostructures have a height of 60nm or 100nm and they have highly ordered layout as they are fabricated through the e-beam technique. The fabrication of the threedimensional structures on the interdigitated electrodes was supposed to improve the sensitivity of the ECIS (electric cell-substrate impedance sensing) measurement while monitoring the cytotoxicity effects of ...
Arias L.R., Carla A.P., Yang L.: Real-Time Electrical Impedance Detection of Cellular Activities of Oral Cancer Cells. Biosensors and Bioelectronics 25(10), 2010, 2225-2231. DOI: https://doi.org/10.1016/j.bios.2010.02.029 Arndt S., Seebach J., Psathaki K., Galla H.J., Wegener J.: Bioelectrical Impedance Assay to Monitor Changes in Cell Shape during Apoptosis. Biosensors and Bioelectronics 19(6), 2004, 583-594. DOI: https://doi.org/10.1016/S0956-5663(03)00269-0 Bagnaninchi P.O., Drummond N.: Real-Time Label-Free Monitoring of Adipose-Derived Stem Cell Differentiation with Electric Cell-Substrate Impedance Sensing. Proceedings of the National Academy of Sciences of the United States of America 108(16), 2011, 6462-6467. DOI: https://doi.org/10.1073/pnas.1018260108 Giaever I., Keese C.R.: A Morphological Biosensor for Mammalian Cells. Nature 366(6455), 1993, 591-592. Hong J., Kandasamy K., Marimuthu M., Choi M.S., Kim S.: Electrical Cell-Substrate Impedance Sensing as a Non-Invasive Tool for Cancer ...
Background: Appendicular skeletal muscle (or lean) mass (ALM) estimated by dual-energy X-ray absorptiometry (DXA) is considered to be a preferred method for sarcopenia studies. However, DXA is expensive, has limited portability, and requires radiation exposure. Bioelectrical impedance analysis (BIA) is inexpensive, easy to use, and portable; thus BIA might be useful in sarcopenia investigations. However, a large variety of models have been commercially supplied by different companies, and for most consumer products, the equations estimating ALM are not disclosed. It is therefore difficult to use these equations for research purposes. In particular, the BIA equation is often age-dependent, which leads to fundamental difficulty in examining age-related ALM loss. The aims of the current study were: 1) to develop and validate an equation to estimate ALM using multi-frequency BIA (MF-BIA) using theoretical models, and 2) to establish sarcopenia cutoff values using the equation for the Japanese
Electric impedance tomography market is expected to gain market growth in the forecast period of 2020 to 2027. Data Bridge Market Research analyses the market to growing at a CAGR of 8.8% in the above-mentioned forecast period. Technological advancements and the rising prevalence of breast cancer are acting as the o...
TY - JOUR. T1 - Body composition in renal transplant patients: bioimpedance analysis compared to isotope dilution, dual energy X-ray absorptiometry, and anthropometry.. AU - van den Ham, E.C.H.. AU - Kooman, J.P.. AU - Christiaans, M.H.. AU - Nieman, F.H.M.. AU - van Kreel, B.K.. AU - Heidendal, G.A.K.. AU - van Hooff, J.P.. PY - 1999/1/1. Y1 - 1999/1/1. N2 - Department of Internal Medicine, University Hospital Maastricht, The Netherlands. [email protected] multifrequency bioelectrical impedance analysis (MF-BIA), a relatively new method for measuring body composition, is also applicable for accurate body composition measurements in renal transplant (RTx) patients is not known. Therefore, the use of MF-BIA is validated in 77 RTx patients with a stable renal function at least 2 yr posttransplantation. MF-BIA is compared to isotope dilution techniques for measurement of body water compartments, and to dual energy x-ray absorptiometry (DEXA) and anthropometry for measurement of ...
Bioelectrical impedance analysis (BIA) is a commonly used method for estimating body composition, and in particular body fat. Since the advent of the first commercially available devices in the mid-1980s the method has become popular owing to its ease of use, portability of the equipment. It is familiar in the consumer market as a simple instrument for estimating body fat. BIA actually determines the electrical impedance, or opposition to the flow of an electric current through body tissues which can then be used to estimate total body water (TBW), which can be used to estimate fat-free body mass and, by difference with body weight, body fat. Many of the early research studies showed that BIA was quite variable and it was not regarded by many as providing an accurate measure of body composition. In recent years technological improvements have made BIA a more reliable and therefore more acceptable way of measuring body composition. Nevertheless, it is not a gold standard or reference method. ...
In 20 mechanically ventilated patients who routinely undergo bronchoscopy Electrical Impedance Tomography (EIT) measurements whereby, evaluable data of 10 patients are needed, of about 1-2 minutes are performed directly before, directly after and 10, 30, and 60 minutes after bronchoscopy parallel to the following routine measurements: tidal volume, resistance, compliance, heart rate, blood pressure, SpO2 and blood gas values. Prior to the examination a rubber belt with 16 integrated electrocardiographic electrodes is placed around the thorax connected with an EIT- device. EIT data are generated by application of a small alternating current of 5mA and 50kHz and are stored and analyzed offline on a personal computer. The EIT provides a mapping of the distribution of the lung´s electrical impedance and exhibits a far temporal resolution of up to 40 tomograms per second. Because of electrical impedance of the pulmonal tissue is dependant to the air content, the air distribution within the lung over ...
Background: Roux-en-Y gastric bypass (RYGB) result in a marked reduction of body fat and also visceral fat (VF) decrease up to 36 % in 16 weeks. This leads to positive effects on cardiometabolic risks, which are known to be correlated with the occurrence of VF. This study analyzed the validity of bioelectrical impedance analysis (BIA) for determining VF in the postoperative course. In addition, magnetic resonance imaging (MRI) was performed for prediction of whole VF in bariatric patients on the basis of a single slice. Methods: Eighteen patients, who underwent RYGB (18), were included in this study. MRI and BIA measurements were performed 1 day before surgery, as well as 6, 12, and 24 weeks after surgery. Results: During the postoperative observation period, we found a significant decrease of both subcutaneous fat (SF) and VF. SF measured by MRI was highly correlated with the level of body fat shown by BIA. In contrast, the VF volume, as determined by MRI, showed no correlation with the body ...
Electrical bioimpedance measurement is widely used today for monitoring body condition. The applications include and go beyond, body composition assessment, nutritional status evaluation, and cancer detection. The modalities for interpreting the impedance information have also developed quickly over the recent decades from single frequency bioimpedance analysis to spectrum and to images.. Bioimpedance is measured by computing the relationship between voltage and current. In a current based bioimpedance measurement system, the stability of current source has a large influence on the performance of the system. This thesis compared three different voltage controlled current sources: enhanced Howland circuit, load-in-the-loop circuit driven by a current conveyor and double operational amplifiers circuit. These circuits were simulated in Multisim and manufactured into prototypes and tested in lab.. Effort has also been made to generate and collect signals with digital-to-analog convertor and ...
VAL104. Belarmino G,Gonzalez MC,Torrinhas RS,Sala P,Andraus W,Carneiro DAlbuquerque LA,Pereira RMR,Caparbo VF,Ravacci GR,Damiani L,Heymsfield SB,Waitzberg DL. World J Hepatol 2017 March 8; 9(7): 401-408. Background: To evaluate the prognostic value of the phase angle (PA) obtained from bioelectrical impedance analysis (BIA) for mortality prediction in patients with cirrhosis.. Subjects /Methods: In total, 134 male cirrhotic patients prospectively completed clinical evaluations and nutritional assessment by BIA to obtain PAs during a 36-mo follow-up period. Mortality risk was analyzed by applying the PA cutoff point recently proposed as a malnutrition marker (PA≤ 4.9°) in Kaplan-Meier curves and multivariate Cox regression models.. Results: The patients were divided into two groups according to the PA cutoff value (PA , 4.9°, n = 73; PA ≤ 4.9°, n = 61). Weight, height, and body mass index were similar in both groups, but patients with PAs , 4.9° were younger and had higher mid-arm muscle ...
TY - JOUR. T1 - Changes in biphasic electrode impedance with protein adsorption and cell growth. AU - Newbold, Carrie. AU - Richardson, Rachael. AU - Millard, Rodney. AU - Huang, Christie. AU - Milojevic, Dusan. AU - Shepherd, Robert. AU - Cowan, Robert. PY - 2010/10. Y1 - 2010/10. N2 - This study was undertaken to assess the contribution of protein adsorption and cell growth to increases in electrode impedance that occur immediately following implantation of cochlear implant electrodes and other neural stimulation devices. An in vitro model of the electrode-tissue interface was used. Radiolabelled albumin in phosphate buffered saline was added to planar gold electrodes and electrode impedance measured using a charge-balanced biphasic current pulse. The polarization impedance component increased with protein adsorption, while no change to access resistance was observed. The maximum level of protein adsorbed was measured at 0.5 μg cm-2, indicating a tightly packed monolayer of albumin molecules ...
Accurate measurement of body fat mass (BFM) is critical in assessing overweight and obesity that pause health implications of other non-communicable diseases (NCDs). The traditional commonly used method, body mass index (BMI) is not adequate to measure BFM because it does not account for body composition. Hence the study measured BFM and free fat mass (FFM) using bioelectrical impedance analysis (BIA) in relation to BMI. This allowed for better estimation of human nutritional status and determination of misclassification when BMI method is used alone. A total of 247 participants, comprising 54% females and 46%males aged 18-55 years were selected from University of Zambia (UNZA), Chalimbana University (CHAU), Natural Resources Development College (NRDC) and Chongwe College of Education (CCE). Participants were further categorized into young adults aged 18-39 years (77%) and old adults aged 40-55 years (23%). Both measurements of BMI and BIA were taken in the morning following overnight fasting ...
The assessment of body composition has important applications in the evaluation of nutritional status and estimating potential health risks. Bioelectrical impedance analysis (BIA) is a valid method for the assessment of body composition. BIA is an alternative to more invasive and expensive methods l …
Application of bioelectrical impedance analysis and anthropometry as interchangeable methods to assess body composition of sportspersons.
0073]1A, 1B, 1C, 1D body fat measurement device [0074]10 control unit [0075]11 calculation processing section [0076]12 impedance measuring portion [0077]13 body fat mass calculating portion [0078]14 total fat mass calculating part [0079]15 site type fat mass calculating part [0080]16 visceral fat mass calculating part [0081]17 subcutaneous fat mass calculating part [0082]18 breathing state detecting portion [0083]21 constant current generation unit [0084]22 terminal switching unit [0085]23 potential difference detection unit [0086]24 physical information measurement unit [0087]25 subject information input unit [0088]26 display unit [0089]27 operation unit [0090]28 power supply unit [0091]29 memory [0092]30 body peripheral length measurement unit [0093]100A, 100A1, 100A2, 100B, 100C, 100D, 100D1 impedance measurement abdomen attachment unit [0094]101 device main body [0095]110A, 110A1, 110D, 110D1 abdomen rear surface side base portion [0096]112 support base [0097]112a one end [0098]112b other ...
Quantifying cell growth is essential for many applications in cell biology and biotechnology. It is required for optimizing cell culture conditions, for studying substances that inhibit or promote cell growth, for studying cancer progression, cytotoxicity assessment, biocompatibility characterization, etc. Traditional cell proliferation assays are label-based endpoint assays that require sample preparation and sophisticated lab equipment. An example of an alternative, label-free technique that is being currently employed for automating cell proliferation studies is electric cell-substrate impedance sending (ECIS). However, ECIS still requires external measurement instruments such as lock-in amplifiers and impedance analyzers. Researchers at the University of Maryland have developed a novel miniaturized technique in which CMOS capacitance sensors are employed to measure the capacitive coupling between on-chip sensing electrodes and the cellular matrix cultured on them, as a means of tracking cell ...
TY - JOUR. T1 - Application of ECIS to assess FCCP-induced changes of MSC micromotion and wound healing migration. AU - Chiu, Sheng Po. AU - Lee, Yu Wei. AU - Wu, Ling Yi. AU - Tung, Tse Hua. AU - Gomez, Sofia. AU - Lo, Chun Min. AU - Wang, Jia Yi. N1 - Funding Information: This work was partially supported by grants from the Tri-Service General Hospital Songshan Branch (grant number 10808) and from the Ministry of Science and Technology of the Republic of China, Taiwan (grant number MOST-102-2628-B-010-010-MY3). Funding Information: Funding: This work was partially supported by grants from the Tri-Service General Hospital Songshan Branch (grant number 10808) and from the Ministry of Science and Technology of the Republic of China, Taiwan (grant number MOST-102-2628-B-010-010-MY3). Publisher Copyright: © 2019 by the authors. Licensee MDPI, Basel, Switzerland.. PY - 2019/7/2. Y1 - 2019/7/2. N2 - Electric cell-substrate impedance sensing (ECIS) is an emerging technique for sensitively monitoring ...
Linköping University, Department of Clinical and Experimental Medicine, Burn Center. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of Plastic Surgery, Hand surgery UHL. Östergötlands Läns Landsting, Sinnescentrum, Department of Anaesthesiology and Surgery UHL. ...
TY - JOUR. T1 - Bioelectrical impedance analysis-derived phase angle at admission as a predictor of 90-day mortality in intensive care patients. AU - Stapel, Sandra N. AU - Looijaard, Wilhelmus G P M. AU - Dekker, Ingeborg M. AU - Girbes, Armand R J. AU - Weijs, Peter J M. AU - Oudemans-van Straaten, Heleen M. PY - 2018/7. Y1 - 2018/7. N2 - BACKGROUND/OBJECTIVES: A low bioelectrical impedance analysis (BIA)-derived phase angle (PA) predicts morbidity and mortality in different patient groups. An association between PA and long-term mortality in ICU patients has not been demonstrated before. The purpose of the present study was to determine whether PA on ICU admission independently predicts 90-day mortality.SUBJECTS/ METHODS: This prospective observational study was performed in a mixed university ICU. BIA was performed in 196 patients within 24 h of ICU admission. To test the independent association between PA and 90-day mortality, logistic regression analysis was performed using the APACHE IV ...
The analysis of electrical signals originating from biological cells and tissues have yielded a large amount of useful information over the past years. Technologies have been developed, wherein we can monitor the health of the biological material of interest using these electrical signals. Instruments for the study of living cells have historically been of significant importance for such things as basic neuroscience, cell biology, pharmaceutical screening, environmental monitoring, and toxin detection. One of the practical realizations of these methods was successfully implemented by Giaver and Keese with their Electric Cell-Substrate Impedance Sensing (ECIS) system. The purpose of this Masters Thesis is to showcase the use of a Cellular Impedance Biosensor setup based on the ECIS system in real-time monitoring of endothelial barrier function and quantify the dynamic changes of the cytoskeleton filaments induced by different drugs. The filaments of the endothelial cell cytoskeleton play a ...
A simple and very accurate method for measuring the viscosity of liquids is presented. A vibrating lead zirconate titanate (PZT) ceramic polycrystalline resonator is totally immersed in a liquid and the oscillation behavior is studied both analytically and experimentally. The vibrating ceramic generates a shear wave traveling in the surrounding fluid normal to the surface of the resonator with heavy damping. The PZT is modeled as a vibrating thin plate. The resulting one-dimensional governing equation of motion, which includes the effect of damping, is solved with the appropriate damped boundary conditions using impedance methods. The resonance frequency of a PZT immersed in a fluid is shown to be a function of the PZT parameters and the product of the fluid density and viscosity. Fluid loading is shown to lower the resonance frequency of the ceramic and both diminish and broaden the impedance plot near resonance. Unlike previous methods utilizing crystal shear-mode resonators, this method is ...
More soldiers become ill or injured from disease and non-battle injuries than from combat, and providing good quality water supplies to the warfighter is a key element in preventing such injuries. Basic field water tests can detect only a few high priority threat chemicals, and comprehensive testing for additional chemicals can takes days or weeks. The ESB provides rapid toxicity identification for many industrial and agricultural chemicals in water. Rather than evaluating individual chemical constituents, the ESB system uses two individual biological-based sensors to identify toxic responses associated with the presence of chemicals: an electric cell-substrate impedance sensing (ECIS) device that measures changes electrical characteristics of a layer of vertebrate cells grown on fluidic biochips, and a pesticide sensor (also known as the ACE™ Rapid Test for Acetylcholinesterase Inhibitors, or ACE™ sensor) that measures enzyme inhibition caused primarily by carbamate and organophosphorus ...
Interelectrode impedance or electric field potential measurements are used to determine the relative orientation of one lead to other leads in the spinal column or other body/tissue location. Interelectrode impedance is determined by measuring impedance vectors. The value of the impedance vector is due primarily to the electrode-electrolyte interface, and the bulk impedance between the electrodes. The bulk impedance between the electrodes is, in turn, made up of (1) the impedance of the tissue adjacent to the electrodes, and (2) the impedance of the tissue between the electrodes. In one embodiment, the present invention makes both monopolar and bipolar impedance measurements, and then corrects the bipolar impedance measurements using the monopolar measurements to eliminate the effect of the impedance of the tissue adjacent the electrodes. The orientation and position of the leads may be inferred from the relative minima of the corrected bipolar impedance values. These corrected impedance values may also
Using a recombinant mini-laminin-332, we showed that truncation of the three C-terminal amino acids of the gamma 2 chain, but not of the C-terminal amino acid of the 133 chain, completely abolished alpha 3 beta 1 integrin binding and its cellular functions, such as attachment and spreading. However, a synthetic peptide mimicking the gamma 2 chain C-terminus did not interfere with 0 l integrin binding or cell adhesion and spreading on laminin-332 as measured by protein interaction assays and electric cell-substrate impedance sensing. Nor was the soluble peptide able to restore the loss of integrin-mediated cell adhesiveness to mini-laminin-332 after deletion of the gamma 2 chain C-terminus. These findings spoke against the hypothesis that the gamma 2 chain C-terminus of laminin-332 is a part of the 0[ l integrin interaction site. in addition, structural studies with electron microscopy showed that truncation of the gamma 2 chain C-terminus opened up the compact supradomain structure of LG1-3 ...
In this study, the bioelectrical impedance analysis (BIA), skinfold thickness measurement (STM) and dual-energy X-ray absorptiometry (DXA), as a reference method, were compared with each other in the assessment of body composition in elderly (62-72-year-old) Finnish women (n=93). BIA had better agreement with DXA in the assessment of fat free mass (FFM, R2=0.70, Sres=2.1) and fat mass (FM, R2=0.93, Sres=2.3) than the STM (FFM, R2=0.62, Sres=2.4; FM, R2=0.89,Sres=2.8). There was quite a large variation in the estimates when different BIA prediction equations were used. The equation developed in this study, FFM (kg)=-128.06 + 1.85 x BMI-0.63 x weight + 1.07 x height - 0.03 x resistance +10.0 x waist-hip ratio, yielded a small and unbiased error (0.5 +/- 1.6 kg), with a small residual standard deviation (R2=0.83, Sres=1.6). However, error associated with the estimate of FM was positively related to the degree of FM. BIA(Heitmann) equation yielded unbiased estimates of both FFM and FM (FFM, R2=0.77, ...
Use of multifrequency bioelectrical impedance analysis for estimation of total body water and extracellular and intracellular fluid volumes in horses ...
SUNNYVALE, CA - November 17, 2008 - MDS Analytical Technologies, a leader in innovative solutions for drug-discovery and life-sciences research, today announced the delivery of the first three CellKeyTM384 Systems, the worlds first impedance-based, label-free, high-throughput instrument for use in drug-discovery research. Additional systems are scheduled to be delivered before the close of the calendar year.
TY - JOUR. T1 - Total body fat and the risk of Barretts oesophagus - A bioelectrical impedance study. AU - Kendall, Bradley J. AU - Macdonald, Graeme. AU - Prins, Johannes. AU - OBrien, Suzanne. AU - Whiteman, David. AU - Green, Adele. AU - Hayward, Nicholas. AU - Parsons, Peter. AU - Pavey, Sandra. AU - Purdie, David. AU - Webb, Penelope. AU - Gotley, David. AU - Smithers, B. AU - Jamieson, Glyn. AU - Drew, Paul. AU - Watson, David. AU - Clouston, Andrew. PY - 2014. Y1 - 2014. N2 - Background: Body mass index is associated with the risk of Barretts oesophagus (BO). It is uncertain whether this is related to total body fat or other factors that correlate with body mass index. We aimed to quantify the association between total body fat (measured by bioelectrical impedance) and risk of BO and examine if this association was modified by gastro-oesophageal reflux (GOR) and abdominal obesity. Methods: In 2007-2009, we surveyed 235 cases (69% Males, Mean age 62.1 years) and 244 age and sex matched ...
Two hundred and fifty seven male Caucasian ultra endurance athletes were recruited, pre-race, before different swimming, cycling, running and triathlon races. Fat mass and skeletal muscle mass were estimated using bioelectrical impedance analysis (BIA) and anthropometric methods in order to investigate whether the use of BIA or anthropometry would be useful under field conditions. Total body fat estimated using BIA was significantly high (P , 0.001) compared with anthropometry. When the results between BIA and anthropometry were compared, moderate to low levels of agreement were found. These results were in accordance with the differences found in the Bland-Altman analysis, indicating that the anthropometric equation of Ball et al. had the highest level of agreement (Bias = -3.0 ± 5.8 kg) with BIA, using Stewart et al. (Bias = -6.4 ± 6.3 kg), Faulkner (Bias = -4.7 ± 5.8 kg)and Wilmore-Siri (Bias = -4.8 ± 6.2 kg). The estimation of skeletal muscle mass using BIA was significantly (P , 0.001) ...
RFS5005A is a development platform for Electrical Impedance Tomography systems. It allows to use single RCL bridge or Impedance analyzer and switch its terminals between up to 16 electrodes. The design ensures low crosstalk and fast switching times. The RFS5005A contains: RFS5003B T-switch multiplexer board, linear- regulated power supply (+5V; -5V; +15V; -15V) and a universal metal rack 19
TY - JOUR. T1 - Identification of the human electrical impedance indifferent point. T2 - A surrogate for the volume indifferent point?. AU - Jarvis, Sara S.. AU - Pawelczyk, James A.. PY - 2009/8/12. Y1 - 2009/8/12. N2 - Head-up tilt (HUT) redistributes ∼700 mL of blood to the dependent regions. In a gravitational field, hydrostatic pressure is balanced against vascular compliance, resulting in a hydrostatic indifferent point (HIP) whose location should be coincident with an indifferent point for volume (VIP). Cardiac filling is determined by the hydrostatic gradient between the HIP/VIP and right atrium. We employed segmental impedance to examine blood volume redistribution during HUT and estimate the location of the VIP. During HUT, impedance increased in the chest and decreased in the lower abdomen, presumably due to blood volume shifts. Using a non-linear model to relate blood volume shifts to the hydrostatic gradient, we estimated the location of the electrical impedance indifferent point ...
Non-invasive single cell analyses are increasingly required for the medicaldiagnostics of test substances or the development of drugs and therapies on the single celllevel. For the non-invasive characterisation of cells, impedance spectroscopy whichprovides the frequency dependent electrical properties has been used. Recently,microfludic systems have been investigated to manipulate the single cells and tocharacterise the electrical properties of embedded cells. In this article, the impedance ofpartially embedded single cells dependent on the cellular behaviour was investigated byusing the microcapillary. An analytical equation was derived to relate the impedance ofembedded cells with respect to the morphological and physiological change ofextracellular interface. The capillary system with impedance measurement showed afeasibility to monitor the impedance change of embedded single cells caused bymorphological and physiological change of cell during the addition of DMSO. By fittingthe derived equation to
The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near
La tunisie medicale : Article medicale COPD patients body composition and its impact on lung function par Meriem Mjid , Houda Snène , Abir Hedhli , Sana Cheikh Rouhou , Sonia Toujani , Besma Dhahri
Experimental setup. (a) Interface impedance measurement (schematic of impedance measurement (left), fabricated MEA on PCB (right)); (b) Charge injection limit m
A portable bioelectric impedance monitor for monitoring extracellular fluid levels includes a tetrapolar electrode array lead with four electrodes arranged sequentially and axially along the lead, and circuitry coupled with the at least four electrodes configured to measure bioelectric impedance extracellular fluid in a human subject at a frequency of less than 15 kHz. The electrodes are adhered to a human subject/patient on the patients torso or one of the patients limbs. One embodiment includes a Tetrapolar Analog Front End Patient Interface circuit configured to convert two electrode operation of a commercial Impedance Converter, Network Analyzer into a tetrapolar operation for excitation and impedance measurement of the human subject.
TY - JOUR. T1 - Myocardial electrical impedance responds to ischemia and reperfusion in humans. AU - Dzwonczyk, Roger. AU - Del Rio, C.. AU - Brown, D. A.. AU - Michler, R. E.. AU - Wolf, R. K.. AU - Howie, M. B.. PY - 2002/12/1. Y1 - 2002/12/1. N2 - Myocardial electrical impedance (MEI) is correlated to ischemia and reperfusion of the heart muscle. The entire body of work with MEI to this point has been carried out in nonhuman animal subjects and excised tissue samples. In this study we measured MEI clinically for the first time in human patients who were undergoing off-pump coronary artery bypass (OPCAB) surgery. Our patient population had a 70-100% stenosis of the coronary artery targeted for bypass. We measured MEI continuously during surgery and at 3, 6, 24 and 72hrs postop from two temporary pacing electrodes attached to heart. MEI increased with occlusion of the diseased artery prior to bypass. The percent increase from baseline was correlated to the percent stenosis of the artery. MEI ...
Electrical properties of food materials can give information about the inner structure and physiological state of biological tissues. Generally, the process of drying of fruits and vegetables is followed by weight loss. The aim of this study was to measure the impedance spectra of carrot slices during drying and to correlate impedance parameters to moisture content in different drying periods. Cylindrical slices were cut out from the carrot root along the axis. The slices were dried in a Venticell 111 air oven at 50°C. The weight of the slices was measured with a DenverSI-603 electronic analytical and precision balance. The weighing of the samples was performed every 30 min at the beginning of drying and every 60 min after the process. The moisture content of the samples was calculated on wet basis. The magnitude and phase angle of electrical impedance of the slices were mea-sured with HP 4284A and 4285A precision LCR meters in thefrequency range from 30 Hz to 1 MHz and from 75 kHz to 30 ...
BIOPAC Biopotential Amplifiers are specialized differential amplifiers designed to amplify the uV and mV level biopotentials that are generated by living organisms. Biopotentials are electrical signals (voltages) that are generated by physiological processes occurring within the body. Biopotentials are produced by the electrochemical activity of a type of cell, called an excitable cell. Excitable cells are found in the nervous, muscular and glandular systems in the body. When an excitable cell is stimulated, it generates an action potential, which is the essential source of biopotentials in the body. The body sources other biopotentials that are not directly related to action potentials. Examples include the corneal-retinal (corneoretinal) potential, skin potential and the electromechanical behavior of bone. In addition, many physiological processes in the body contribute to measurable impedance changes. Impedance changes are sensed by applying external excitation signals that convert impedance ...
In children 8-12 years old, BMI gives a good estimation of the total body fat as measured on MRI. The estimation will be improved when both BEI and BMI are used in the prediction. Bioelectrical impedance has a low correlation with total body fat and its use alone in estimating total body fat is not …
High-frequency digital sign processors suffer from electro-magnetic disturbance, because of its ever-increasing integration procedure and level acceleration. can be proportional to range can be inversely proportional to range and C inversely. Therefore, simplified equivalence, as well as the impedance can be depicted in Fig.?3. Fig.?3 Comparative circuit magic size As is demonstrated in Fig.?4, to be able to determine guidelines from the circuit, means the exterior impedance from the source, for the same internal current way to obtain the LSI/IC under measurement, as well as for the same internal impedance of these devices under measured. These devices internal impedance could be assessed by an impedance analyser, as can be proven in Fig.?5. The resonance frequency could be observed through the impedance diagram then. The resulting guidelines (and with an impedance analyser The exterior circuit current could KW-2449 be assessed by a range analyser as well as the particular sketch can be ...
Measuring and Managing Healthy Living The US spends more on healthcare per capita ($8668) and more on healthcare as a percentage of GDP (17.2%) than any other nation. From 2011 data
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