Geselowitz D B, Ferrara J E
Bioengineering Program, Pennsylvania State University, University Park 16801, USA.
IEEE Trans Biomed Eng. 1999 Apr;46(4):377-81. doi: 10.1109/10.752934.
Experimental and model studies were performed to measure the electrocardiographic surface Laplacian using a rectangular finite difference approximation. The experimental approach used ten normal subjects with two sites on the torso. Electrode spacing was 2 cm. The surface Laplacian is theoretically independent of rotation of the electrode array. The data showed considerable variation with rotation. Model studies employed a realistic 23-dipole source. A spherical volume conductor showed invariance with rotation, as anticipated theoretically. A realistic torso, however, showed variation with rotation, although not as severe as that measured. A separate experimental study considered the signal-to-noise ratio (SNR) for the surface Laplacian. The average SNR was 3.3 and 2.5 at the two sites. These results raise serious questions about the practical ability to measure the surface Laplacian on the torso.
进行了实验研究和模型研究，以使用矩形有限差分近似法测量心电图表面拉普拉斯算子。实验方法是选取十名正常受试者，在其躯干上设置两个部位。电极间距为2厘米。理论上，表面拉普拉斯算子与电极阵列的旋转无关。但数据显示，随着旋转会有相当大的变化。模型研究采用了一个逼真的23偶极子源。如理论预期，球形容积导体随旋转保持不变。然而，一个逼真的躯干模型随旋转出现了变化，尽管不如实测的那么严重。另一项实验研究考虑了表面拉普拉斯算子的信噪比（SNR）。两个部位的平均信噪比分别为3.3和2.5。这些结果对在躯干上测量表面拉普拉斯算子的实际能力提出了严重质疑。
