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Improved estimation of left ventricular volume from electric field modeling Cover

Improved estimation of left ventricular volume from electric field modeling

Journal of Electrical Bioimpedance
Volume 12 (2021): Issue 1 (January 2021)
By: Leonie Korn,  Stephan Dahlmanns,  Steffen Leonhardt and  Marian Walter  
Open Access
|Dec 2021

Figures & Tables

Figure 1

Electric field distribution of to spheres with opposite charges Q (red) and -Q (blue). The measurement electrodes (green) are distanced by L. Background tissue (σba = 0) is assumed.
Electric field distribution of to spheres with opposite charges Q (red) and -Q (blue). The measurement electrodes (green) are distanced by L. Background tissue (σba = 0) is assumed.

Figure 2

Electric field distribution by applying the voltages -V0 (red) on a sphere and V0′=+V0 $V_{0}^{\prime }=+{{V}_{0}}$on a spare charge plate (blue). The measurement electrodes (green) are distanced by L. Muscle tissue (σm) with a thickness of b and background tissue (σba) are modeled.
Electric field distribution by applying the voltages -V0 (red) on a sphere and V0′=+V0 $V_{0}^{\prime }=+{{V}_{0}}$on a spare charge plate (blue). The measurement electrodes (green) are distanced by L. Muscle tissue (σm) with a thickness of b and background tissue (σba) are modeled.

Figure 3

Left: electric field distribution of the injection at the outer electrodes with distance d. Middle: electric field distribution of the injection at the inner electrodes with distance L. Right: electric field distribution considering both the injection and the measurement field according to lead field theory.
Left: electric field distribution of the injection at the outer electrodes with distance d. Middle: electric field distribution of the injection at the inner electrodes with distance L. Right: electric field distribution considering both the injection and the measurement field according to lead field theory.

Figure 4

Left: five cylindrical glass containers representing simplistic volumes to test the measurement system and calculation methods. 1: radius 13.3 mm, 2: radius 17.5 mm, 3: radius 32.8 mm, 4: radius 38.6 mm, 5: radius 50.4 mm. Right: close-up on the measurement catheter and a possible cascaded measurement configuration.
Left: five cylindrical glass containers representing simplistic volumes to test the measurement system and calculation methods. 1: radius 13.3 mm, 2: radius 17.5 mm, 3: radius 32.8 mm, 4: radius 38.6 mm, 5: radius 50.4 mm. Right: close-up on the measurement catheter and a possible cascaded measurement configuration.

Figure 5

a) Left ventricular in-vitro phantoms made from silicone (left: carbon, right: pure), b) C-arm with manual test bench to measure phantom dimension, c) Cross-sectional areas obtained from CT measurements at the center electrode pair, adapted from [32].
a) Left ventricular in-vitro phantoms made from silicone (left: carbon, right: pure), b) C-arm with manual test bench to measure phantom dimension, c) Cross-sectional areas obtained from CT measurements at the center electrode pair, adapted from [32].

Figure 6

Estimated radii using the classical Wei, the plate, and the lead ACM compared to the known radii of the cylinders (Data). Left: conductivity of saline solution σ1 = 1.69 S/m, right: conductivity of saline solution σ2 = 0.62 S/m.
Estimated radii using the classical Wei, the plate, and the lead ACM compared to the known radii of the cylinders (Data). Left: conductivity of saline solution σ1 = 1.69 S/m, right: conductivity of saline solution σ2 = 0.62 S/m.

Figure 7

Estimated radii by the ACMs (Wei, Plate, Lead) obtained from the conductances measured inside the in-vitro phantoms compared to reference radii (Data). Left: insulating phantom of pure silicone, right: silicone phantom enriched with carbon.
Estimated radii by the ACMs (Wei, Plate, Lead) obtained from the conductances measured inside the in-vitro phantoms compared to reference radii (Data). Left: insulating phantom of pure silicone, right: silicone phantom enriched with carbon.

Measured volumes inside the silicone ventricle from CT measurements_ Cross-sectional areas obtained between the center electrode pair_ Estimated equivalent center radius_

StepVolume (mL)Area (mm2)Radius (mm)
1117.901248.8419.94
2107.121022.5518.04
397.96855.5016.50
487.20683.1514.75
576.84506.8312.70
669.46401.1211.30
DOI: https://doi.org/10.2478/joeb-2021-0015 | Journal eISSN: 1891-5469
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Language: English
Page range: 125 - 134
Submitted on: Jun 16, 2021
Published on: Dec 27, 2021
Published by: University of Oslo
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year
Keywords:
Left ventricular volume,
Electric field distribution,
LVAD
Related subjects:
Engineering,
Bioengineering and biomedical engineering,
Biomedical electronics,
Life sciences,
Biophysics,
Medicine,
Biomedical engineering,
Physics,
Spectroscopy and metrology

© 2021 Leonie Korn, Stephan Dahlmanns, Steffen Leonhardt, Marian Walter, published by University of Oslo
This work is licensed under the Creative Commons Attribution 4.0 License.

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