Related Experiment Video
Updated: Feb 3, 2026

Evaluation of Fluid Overload by Bioelectrical Impedance Vectorial Analysis
Published on: August 17, 2022
Intrathoracic fluid changes from preconception to postpartum as measured by bio-impedance monitoring
Dorien Lanssens1,2, Christophe J P Smeets2,3, Pieter Vandervoort2,3
1Department of Gynaecology, Ziekenhuis Oost-Limburg, Genk, Belgium.
Intrathoracic impedance was remotely monitored from preconception to postpartum in a woman with an implantable cardioverter defibrillator. At 6 and 20 weeks, two significant changes were recorded, suggestive for thoracic fluid accumulation. After normal outcome, postpartum intrathoracic impedance returned to preconception values. The obtained results from this case report show that these measurements can be obtained with an implanted device. Current devices for measuring cardiac output by impedance technique allow evaluating thoracic fluid changes non-invasively. As such, non-invasive impedance monitoring may be a potential new method for continuous monitoring of maternal vascular changes during any time window between preconception and postpartum, to be assessed in a large cross sectional observational study.
Intrathoracic impedance was remotely monitored from preconception to postpartum in a woman with an implantable cardioverter defibrillator. At 6 and 20 weeks, two significant changes were recorded, suggestive for thoracic fluid accumulation. After normal outcome, postpartum intrathoracic impedance returned to preconception values. The obtained results from this case report show that these measurements can be obtained with an implanted device. Current devices for measuring cardiac output by impedance technique allow evaluating thoracic fluid changes non-invasively. As such, non-invasive impedance monitoring may be a potential new method for continuous monitoring of maternal vascular changes during any time window between preconception and postpartum, to be assessed in a large cross sectional observational study.
Related Concept Videos
Measurement of Fluid Pressure
A basic form of manometer is the piezometer, a vertical tube open at the top and filled with the same...
Impedance Combination
Impedances and Admittance
Impedance is a measure of resistance to sinusoidal current flow in an AC circuit. Unlike their behavior in DC circuits, where inductors appear as short circuits and capacitors as open circuits, the behavior of these components in AC...
Series Impedances: Three-Phase Line
Using Kirchhoff's laws, an integro-differential equation for the network is derived. This equation accounts for unbalanced phase currents, which may induce return currents through neutral wires and the earth, seeking the least impedance path. Earth return conductors can replace the...
Bus Impedance Matrix
In the first circuit, all machine voltage sources are short-circuited, leaving only the prefault voltage source at the fault location. The positive-sequence bus impedance matrix can be determined by solving the nodal equations,...
Line Protection with Impedance Relays
Under normal conditions, low load currents keep the measured...

