On the algorithm for computing body surface Laplacians in an inhomogeneous volume conductor of arbitrary shape

Area of Science:

• Biomedical Engineering
• Computational Electrophysiology
• Medical Physics

Background:

• Calculating the body surface Laplacian (BSL) is crucial for interpreting electrophysiological signals.
• Previous algorithms for BSL calculation in inhomogeneous media faced accuracy limitations.
• Understanding the influence of internal conductivity variations, like lungs, on BSL is important for source localization.

Purpose of the Study:

• To present a corrected algorithm for accurate BSL calculation in arbitrarily shaped, inhomogeneous volume conductors.
• To evaluate the impact of lung inhomogeneity on BSL using a realistic torso model.
• To assess the effect of lung conductivity on the topology and magnitude of body surface Laplacian maps (BSLM).

Main Methods:

• Development and validation of a corrected numerical algorithm for BSL computation.
• Computer simulations employing a realistically shaped torso model with inhomogeneous lung regions.
• Analysis of BSLM for a single dipole source under varying lung conductivity conditions.

Main Results:

• The corrected algorithm provides an accurate numerical solution for BSL calculation.
• Simulation results demonstrate that low-conductivity lungs have a negligible effect on BSLM topology.
• The presence of lungs minimally influences the magnitudes of BSLM for a single dipole source.

Conclusions:

• The corrected BSL algorithm is reliable for complex anatomical models.
• Lung inhomogeneity does not significantly alter BSLM characteristics for dipole sources.
• This finding simplifies the interpretation of body surface potential data in the presence of lung variations.