Hosaka H, Cohen D, Cuffin B N, Horacek B M
J Electrocardiol. 1976;9(4):418-25. doi: 10.1016/s0022-0736(76)80042-8.
The magnetic field produced by a current dipole is made up of two parts: the field from the dipole element, and from the current generated by the dipole in the volume conductor. It was previously shown for the semi-infinite volume conductor, infinite slab, and the sphere that the volume-current contribution is zero to the component of magnetic field which is normal to the boundary. The volume conductor in the form of the human torso is here investigated by computer simulation. Three different heart-torso models are used. The contribution to the normal field component (Bn) by the volume current (via the boundaries) and by the heart dipoles are computed. For comparison, the boundary contribution to the surface potential (V) is also computed. For Bn the three models yield a ratio of boundary to dipole contribution in the same range, with 0.28 as the average. Simple subtractions can make this ratio negligible. For V the equivalent ratio is somewhat greater. The arrow map, developed previously to display Bn over special surfaces, is shown to be valid for the human torso, for visually estimating the heart dipoles.
偶极子元件产生的场，以及偶极子在容积导体中产生的电流产生的场。先前已针对半无限容积导体、无限平板和球体表明，容积电流对垂直于边界的磁场分量的贡献为零。本文通过计算机模拟研究人体躯干形式的容积导体。使用了三种不同的心脏-躯干模型。计算了容积电流（通过边界）和心脏偶极子对法向场分量（Bn）的贡献。为作比较，还计算了边界对表面电位（V）的贡献。对于Bn，三种模型产生的边界与偶极子贡献的比率在相同范围内，平均值为0.28。简单相减可使该比率忽略不计。对于V，等效比率稍大一些。先前开发的用于在特殊表面上显示Bn的箭头图被证明对人体躯干有效，可用于直观估计心脏偶极子。
