G. Fischer et al., ANALYTICAL VALIDATION OF THE BEM - APPLICATION OF THE BEM TO THE ELECTROCARDIOGRAPHIC FORWARD AND INVERSE PROBLEM, Computer methods and programs in biomedicine, 55(2), 1998, pp. 99-106
The objective of this study is to analytically validate a boundary ele
ment (BE) formulation for the relationship between the transmembrane p
otential on the heart's surface and the potential on the body surface
applying a concentric spherical test geometry. The relative difference
(reldif) between the potential on the outer sphere of the test geomet
ry computed analytically and numerically is determined by 3.59% for th
e coarse discretization (48 BEs) and by 0.46% in the case of the finer
subdivision (192 BEs). In the inverse problem, the transmembrane pote
ntial on the inner sphere is estimated numerically from the electric p
otential on the outer sphere by using a minimum-norm least-square appr
oach. The relative differences found are 20.2% when no measurement noi
se is added and 26.4% in the presence of 2% additional Gaussian noise.
The BE formulation is also applied to real world data for solving the
electrocardiographic inverse problem. A normal volunteer's inhomogene
ous thorax (outer thorax surface, surfaces of the lungs, epicardial he
art surface) is modelled by 424 BEs. The same inverse method is then a
pplied in order to reconstruct the transmembrane potential on the epic
ardium from the measured body surface potential (BSP) data during norm
al ventricular depolarisation. (C) 1998 Elsevier Science Ireland Ltd.
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