Institute of Biomaterials and Biomedical Engineering, University of Toronto, ON, Canada.
IEEE Trans Neural Syst Rehabil Eng. 2011 Apr;19(2):147-56. doi: 10.1109/TNSRE.2010.2091429. Epub 2010 Nov 11.
The task of discriminating the neural pathways responsible for the activity recorded using a multi-contact nerve cuff electrode has recently been approached as an inverse problem of source localization, similar to EEG source localization. A major drawback of this method is that it requires a model of the nerve, and that the localization performance is highly dependent on the accuracy of this model. Using recordings from a 56-contact "matrix" cuff electrode placed on a rat sciatic nerve, we investigated a method that eliminates the need for a model, and uses instead an "experimental" leadfield constructed from a training set of experimental recordings. The resulting pathway-identification task is solved using an inverse problem framework. The experimental leadfield approach was able to identify the correct branch in cases in which a single fascicle was active with a success rate of 94.2%, but was not able to reliably identify combinations of fascicles. Nevertheless, the proposed methodology provides a framework for the study of multi-pathway discrimination, within which methods to improve performance can be investigated. Specifically, the influence of nerve anatomy and electrode design should be examined, and regularization approaches better suited to this novel inverse problem should be sought.
最近，人们将使用多触点神经袖套电极记录的活动的神经通路区分任务作为源定位的逆问题来处理，类似于 EEG 源定位。这种方法的一个主要缺点是它需要一个神经模型，并且定位性能高度依赖于该模型的准确性。我们使用放置在大鼠坐骨神经上的 56 触点“矩阵”袖套电极的记录，研究了一种不需要模型的方法，而是使用来自实验记录的训练集构建“实验”引导场。使用逆问题框架解决由此产生的通路识别任务。实验引导场方法在单个纤维束活动的情况下能够以 94.2%的成功率识别正确的分支，但不能可靠地识别纤维束的组合。尽管如此，所提出的方法学为多通路辨别研究提供了一个框架，在这个框架内可以研究提高性能的方法。具体来说，应该检查神经解剖结构和电极设计的影响，并寻求更适合这种新逆问题的正则化方法。
