Electrocardiographic simulation on personalised heart-torso structures using coupled meshfree-BEM platform

Abstract

The foremost premise for the success of noninvasive volumetric myocardial Transmembrane (TMP) imaging from Body Surface Potential (BSP) recordings is a realistic yet efficient TMP-to-BSP mapping model that balances model accuracy with reconstruction feasibility. This papers presents a novel coupled meshfree-BEM platform to this forward electrocardiographic modelling. Its numerical accuracy and convergence is quantitatively assessed against analytical solutions on a synthetic geometry. Electrocardiographic simulations of various cardiac conditions

Noninvasive Transmural Electrophysiological Imaging Based on Minimization of Total-Variation Functional

“…In this study, (3) and (4) are solved with the coupled meshfree and boundary element methods [29], [30]. The value of anisotropic intracellular conductivity tensor , bulk conductivity , and torso conductivity are adopted from [31].…”

“…Therefore, we define an alternative approximation of the continuous form of TV as (10) where a numerical integration is performed over the 3-D myocardial field by (at the order of ) Gaussian quadrature points. Depending on the discretization method used (such as the finite element method or meshfree method [33] used in our study [29], [30]), on each Gauss point is approximated by a linear combination of its neighboring nodal points in the discrete field based on the spatial gradient of the shape function . Because each Gauss point has only a small set of support nodal points, and are sparse with a small number of nonzero values.…”

“…Fig. 2(a) and (b) give one example where the homogeneous torso model is represented with boundary-element mesh and the 3-D ventricular model is represented with meshfree nodes [29], [30]. We focus on the ability of the proposed reconstruction method to: 1) outline the steep gradient of action potential along the border of the infarcted or ischemic region that separates the region of necrotic/inactive and healthy/active tissue during the ST-segment of an ECG cycle, and 2) reconstruct the excitation wavefront in both normal and diseased hearts so as to reveal the underlying block (disease substrate) to the conduction path.…”

“…Ventricular models for both patients were built from their MRI as described in [30]. A homogenous torso model of each patient was obtained by deforming the standard Dalhousie torso model given by the 2007 PhysioNet/Computers in Cardiology Challenges to limited whole-body MR scans of each patient via host mesh customization method [5].…”

Electrophysiological imaging of volumetric infarct border using a spatio-temporal LP-norm constraint

“…The Laplace equation (2) describes, on the monodomain torso model, how the potential φ distributes within the torso volume Ω t/h external to the heart with conductivity σ. It has been previously shown that, using proper numerical methods such as mesh free and boundary element methods, one can numerically solve equation (1,2) on a subject heart-torso model, and obtain linear relationship: b = Hv [11].…”