SAMPLING THEORY FOR NEUROMAGNETIC DETECTOR ARRAYS
SAMPLING THEORY FOR NEUROMAGNETIC DETECTOR ARRAYS
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DOI：
10.1109/10.245606
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发表时间：
1993-09-01
影响因子：
4.6
通讯作者：
VILKMAN, VA
中科院分区：
文献类型：
--
作者：
AHONEN, AI;HAMALAINEN, MS;VILKMAN, VA
本文将波数有限的多变量函数的采样定理应用于神经磁映射问题。估计了这些场的波数谱和其它有关性质。导出了一种用于从使用传感器阵列的测量中重建神经磁场的理论，所述传感器阵列对垂直于测量点的平面网格的场分量B（z）或其梯度在xy平面中的两个分量偏导数B（z）/偏导数x和偏导数B（z）/偏导数y进行采样。对于这两种情况，确定与唯一重建一致的最大传感器间距。它示出，当两个正交分量的梯度测量在每个站点的测量网格，这些传感器对单元的密度可以减少，没有混叠的风险，到一半的是什么是必要的单通道传感器在阵列采样B。一个人因此，平面和轴向梯度仪阵列在采样意义上是等效的，前提是每单位面积的独立测量次数相等。
The sampling theorem for wave-number-limited multivariable functions is applied to the problem of neuromagnetic field mapping. The wave-number spectrum and other relevant properties of these fields are estimated. A theory is derived for reconstructing neuromagnetic fields from measurements using sensor arrays which sample either the field component B(z) perpendicular to the planar grid of measurement points, or the two components partial derivative B(z)/partial derivative x and partial derivative B(z)/partial derivative y of its gradient in the xy plane. The maximum sensor spacing consistent with a unique reconstruction is determined for both cases. It is shown that, when two orthogonal components of the gradient are measured at every site of the measurement grid, the density of these sensor-pair units can be reduced, without risk of aliasing, to half of what is necessary for single-channel sensors in an array sampling B. alone. Thus the planar and axial gradiometer arrays are equivalent in the sampling sense provided that the number of independent measurements per unit area is equal.