首页|High-frequency SSVEP-BCI system for detecting intermodulation frequency components using task-discriminant component analysis

High-frequency SSVEP-BCI system for detecting intermodulation frequency components using task-discriminant component analysis

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© 2024 Elsevier LtdRecently, steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) has significantly progressed and is moving from the laboratory to practical application. However, the system performance and comfort of SSVEP-BCIs still need to be improved. In this study, five flicker frequencies (i.e., 30–34 Hz with an interval of 1 Hz) and eight scaling frequencies (i.e., 0.4–1.8 Hz with an interval of 0.2 Hz) were adopted to jointly encode forty visual stimulus targets using evoked intermodulation (IM) frequency components. Both luminance and shape changes are implemented by sinusoidal sampling stimulus coding methods. High-frequency flicker frequencies and green visual stimuli were chosen to improve the comfort of the proposed system. An extended version of a training algorithm named task-discriminant component analysis (TDCA) was proposed to detect the IM components of SSVEP signals. The average recognition accuracy of eleven subjects is 96.82 ± 0.01 % in the offline experiments for a data length of 5 s. Online validation experiments was constructed from the optimized parameters of offline analysis, and the average accuracy and ITR were 94.37 ± 1.17 % and 113.47 ± 2.60 bits/min, respectively. Furthermore, ten subjects who participated in the validation part also completed the online free-spell task successfully. These results showed that it is feasible to expand the number of stimulus targets by using IM frequency components of SSVEP signals for target coding, and that the system performance is superior.

Brain-computer interfaceHigh frequency steady-state visual evoked potentialIntermodulation frequenciesTask-discriminant component analysis

Cui H.、Li M.、Chen X.、Ma X.

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Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical College||Tianjin Key Laboratory of Neuromodulation and Neurorepair Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical College

Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical College

People's Hospital of Ningxia Hui Autonomous Region||Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical College

2025

Biomedical signal processing and control

Biomedical signal processing and control

SCI
ISSN:1746-8094
年,卷(期):2025.99(Jan.)
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