Yanmei Tie and Mesut Sahin 2005 J. Neural Eng. 2 90 doi:10.1088/1741-2560/2/4/004
Yanmei Tie and Mesut Sahin
Show affiliationsEvoked motor signals descending down the corticospinal tract can be recorded selectively with multi-contact electrodes from the spinal cord surface. This method of extracting motor signals from the spinal cord may provide a means of communication for people with spinal cord injury. The information rate obtained with such an interface will improve if the separation of neural channels can be increased. In this study, the feasibility of increasing the channel separation was investigated using the blind source separation (BSS) technique. Neural signals recorded with multi-contact surface electrodes were treated as a linear mixture of independent neural sources located inside the spinal cord. Principal component analysis (PCA) was applied to estimate the dimensionality of the raw signals, and then the fixed-point FastICA algorithm was used to separate the primary neural sources from the secondary (smaller) ones. In all trials but one, the separation between the neural channels has increased by eliminating the secondary sources. These results suggest that the information rate of a spinal cord interface can be improved by separating the neural recordings into their independent components and selecting the ones with the largest distance between them. Comparison of independent component analysis (ICA) and PCA reveals that ICA performs better in this application.
87.80.-y Biophysical techniques (research methods)
02.50.-r Probability theory, stochastic processes, and statistics
87.19.R- Mechanical and electrical properties of tissues and organs
Issue 4 (December 2005)
Received 29 July 2005, accepted for publication 12 August 2005
Published 30 September 2005
Yanmei Tie and Mesut Sahin 2005 J. Neural Eng. 2 90
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