Title
An adaptive CSP filter to investigate user independence in a 3-class MI-BCI paradigm.
Abstract
This paper describes the implementation of a Brain Computer Interface (BCI) scheme using a common spatial patterns (CSP) filter in combination with a Recursive Least Squares (RLS) approach to iteratively update the coefficients of the CSP filter. The proposed adaptive CSP (ACSP) algorithm is made more robust by introducing regularization using Diagonal Loading (DL), and thus will be able to significantly reduce the length of training sessions when introducing new patients to the BCI system. The system is tested on a 4-class multi-limb motor imagery (MI) data set from the BCI competition IV (2a), and a more complex single limb 3-class MI dataset recorded in-house. The latter dataset is produced to mimic an upper limb rehabilitation session, e.g., after stroke. The findings indicate that when extensive calibration data is available, the ACSP performs comparably to the CSP (kappa value of 0.523 and 0.502, respectively, for the 4-class problem); for reduced calibration sessions, the ACSP significantly improved the performance of the system (up to 4-fold). The proposed paradigm proved feasible and the ACSP algorithm seems to enable a user or semi user independent scenario, where the need for long system calibration sessions without feedback is eliminated.
Year
DOI
Venue
2018
10.1016/j.compbiomed.2018.09.021
Computers in Biology and Medicine
Keywords
Field
DocType
Electroencephalography(EEG),Common spatial patterns (CSP),Brain-computer interface (BCI),Motor imagery (MI),Diagonal loading (DL) CSP (DLCSP),Recursive least squares (RLS),Stroke rehabilitation
Diagonal,Pattern recognition,Computer science,Brain–computer interface,Regularization (mathematics),Artificial intelligence,Recursive least squares filter,Motor imagery
Journal
Volume
ISSN
Citations 
103
0010-4825
3
PageRank 
References 
Authors
0.41
18
4
Name
Order
Citations
PageRank
Ana. P. Costa130.41
Jakob S. Møller2171.73
Helle K Iversen3183.56
Sadasivan Puthusserypady418127.49