NEUROMAGNETIC SOURCE IMAGING WITH FOCUSS - A RECURSIVE WEIGHTED MINIMUM NORM ALGORITHM
NEUROMAGNETIC SOURCE IMAGING WITH FOCUSS - A RECURSIVE WEIGHTED MINIMUM NORM ALGORITHM
复制标题
DOI：
10.1016/0013-4694(95)00107-a
复制
发表时间：
1995-10-01
期刊：
影响因子：
--
通讯作者：
RAO, BD
中科院分区：
文献类型：
--
作者：
GORODNITSKY, IF;GEORGE, JS;RAO, BD
提出了一种新的神经电磁场逆问题层析成像源重建算法。这种算法被称为FOCUSS(焦点欠确定系统解)，它结合了两种主要电磁逆程序方法的理想特性。与当前的多种偶极子建模方法一样，FOCUSS可以为电磁成像中经常遇到的高度局域化的源提供高分辨率的解决方案。与线性估计方法一样，FOCUSS允许电流源呈现任意形状，并保留了这组方法的通用性和易用性。它不同于标准的信号处理技术，因为作为一种依赖于初始化的算法，它适应了由于神经电源限制而产生的非唯一可行解集合。FOCUSS基于递归加权范数最小化。重复加权过程的结果实际上是将溶液集中在对准确重现测量结果至关重要的最小有效区域。介绍了FOCUSS算法，并在大量仿真的背景下说明了它的性质，首先在2-D和3-D问题中使用精确的测量，然后在存在噪声和建模误差的情况下。结果表明，FOCUSS是一种强大的层析电流估计算法，具有一定的实用价值。
The paper describes a new algorithm for tomographic source reconstruction in neural electromagnetic inverse problems. Termed FOCUSS (FOCal Underdetermined System Solution), this algorithm combines the desired features of the two major approaches to electromagnetic inverse procedures. Like multiple current dipole modeling methods, FOCUSS produces high resolution solutions appropriate for the highly localized sources often encountered in electromagnetic imaging. Like linear estimation methods, FOCUSS allows current sources to assume arbitrary shapes and it preserves the generality and ease of application characteristic of this group of methods. It stands apart from standard signal processing techniques because, as an initialization-dependent algorithm, it accommodates the non-unique set of feasible solutions that arise from the neuroelectric source constraints. FOCUSS is based on recursive, weighted norm minimization. The consequence of the repeated weighting procedure is, in effect, to concentrate the solution in the minimal active regions that are essential for accurately reproducing the measurements. The FOCUSS algorithm is introduced and its properties are illustrated in the context of a number of simulations, first using exact measurements in 2- and 3-D problems, and then in the presence of noise and modeling errors. The results suggest that FOCUSS is a powerful algorithm with considerable utility for tomographic current estimation.