Bioelectrical Impedance Analysis
Bioelectrical Impedance Analysis - Related Videos
07:17
Evaluation of Fluid Overload by Bioelectrical Impedance Vectorial Analysis
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Cited by 1 •
2022
In this study, we demonstrate how to evaluate the presence of fluid overload through bioelectrical impedance vectorial analysis (BIVA) and the impedance ratio measured using tetrapolar multi-frequency equipment in patients admitted to the emergency department. BIVA and impedance ratio are reliable and useful tools to predict poor outcomes.
05:16
Cutoff Value of Phase Angle by Bioelectrical Impedance Analysis at Admission as a Prognostic Factor in Patients with Acute Heart Failure
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Cited by 1 •
2025
This protocol presents R codes for performing restricted cubic spline multivariable Cox regression analysis to determine the cutoff value of the phase angle for prognosis in acute heart failure as well as codes for calculating statistics that measure the discriminatory ability of each model and evaluate its goodness of fit.
07:44
Evaluation of Changes in Hydration and Body Cell Mass with Bioelectrical Impedance Analysis after Exercise Program for Rheumatoid Arthritis Patients
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Cited by 1 •
2023
This protocol assesses alterations in hydration and body cell mass status using bioelectrical impedance vectorial analysis following a dynamic exercise program designed for patients with rheumatoid arthritis. The dynamic exercise program itself is detailed, highlighting its components focused on cardiovascular capacity, strength, and coordination. The protocol details steps, instruments, and limitations.
10:21
Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test
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2023
Hydration status imbalances can have a short-term effect on direct and indirect determinants of oxygen uptake and pulse, and morbidity and mortality prognostic factors in ischemic heart disease. This protocol describes the technique for assessment of hydration status through bioelectrical impedance vector analysis and cardiopulmonary response during exercise stress test.
07:28
Measurement of Bioelectric Current with a Vibrating Probe
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Cited by 15 •
2011
The manufacture, calibration and use of non-invasive vibrating probes to measure bioelectric current in various biological systems is described.
FAQs
Measurement frequency is a key control variable because BIA results depend on it. The measured impedance reflects resistance from tissue fluids and reactance associated with cell membranes, and changing frequency can alter how those electrical properties contribute to the reading. Researchers therefore interpret composition estimates alongside the selected frequency rather than treating impedance as frequency-independent.
Resistance and reactance represent different electrical properties within the measured tissue. Resistance is associated with the opposition produced by tissue fluids, whereas reactance is linked to cell membranes. Considering both components gives BIA more information than a single resistance value and supports algorithms that relate electrical measurements to total body water, fat-free mass, and body fat.
These factors can change the measured electrical pathway and therefore influence impedance. Hydration status affects the tissue-fluid contribution to resistance, while body geometry and electrode placement affect how the current and voltage measurement relate to the body. Consequently, changes in a BIA result may reflect measurement conditions as well as actual changes in body composition.
A BIA measurement introduces a small alternating electrical current through electrodes and measures the resulting voltage. The instrument uses these electrical values to calculate impedance, including resistance and reactance. Algorithms then relate the impedance measurement to estimates such as total body water, fat-free mass, and body fat, while interpretation considers frequency, electrode placement, geometry, and hydration.
Researchers use BIA when they need a practical, noninvasive way to assess electrical properties of biological tissues or monitor changes in hydration and body composition. Its measurement approach can support biomedical research without requiring an invasive procedure. The resulting estimates remain dependent on measurement conditions, so researchers must consider hydration status, frequency, geometry, and electrode placement.
BIA can provide impedance measurements that describe how tissue responds electrically, along with algorithm-based estimates of total body water, fat-free mass, and body fat. In physics, these measurements connect electrical behavior with tissue properties. In biomedical research, repeated assessments can help monitor changes in hydration or composition, provided the relevant measurement conditions are considered.