Wischmann H A, Fuchs M, Dössel O
Philips GmbH Forschungslaboratorien, Forschungsabteilung Technische Systeme Hamburg, Germany.
Brain Topogr. 1992 Winter;5(2):189-94. doi: 10.1007/BF01129049.
Currently, linear estimation reconstruction is the only feasible method for extracting information about spatially distributed current sources from measurements of neural magnetic fields. We present the results of a systematic study of the effect of the signal-to-noise ratio on the imaging quality of one such algorithm in over-as well as undetermined circumstances. In particular, we will discuss the necessary trade-off between the contradictory goals of a minimum norm of the reconstructed current density distribution and of a minimal deviation of the reconstructed fields from the measured fields. As an example, we show the reconstruction of a simple arrangement of two nearly parallel dipoles in two different depths inside a spherical volume conductor, discussing the differences between the computer simulation without noise and simulation with a realistic noise level.
目前，线性估计重建是从神经磁场测量中提取关于空间分布电流源信息的唯一可行方法。我们展示了一项系统研究的结果，该研究考察了信噪比在超定和欠定情况下对一种此类算法成像质量的影响。特别是，我们将讨论在重建电流密度分布的最小范数与重建场与测量场的最小偏差这两个相互矛盾的目标之间进行必要权衡的问题。作为一个例子，我们展示了在球形体积导体内部两个不同深度处两个近乎平行偶极子的简单排列的重建情况，并讨论了无噪声计算机模拟与具有实际噪声水平模拟之间的差异。
