A Synchronized Hybrid Brain-Computer Interface System for Simultaneous Detection and Classification of Fusion EEG Signals

Dalin Yang,Trung-Hau Nguyen,Wan-Young Chung

doi:10.1155/2020/4137283

Abstract

Brain-computer interface (BCI) technology represents a fast-growing field of research and applications for disabled and healthy people, which is a direct communication pathway to translate the neural information into an active command. Owing to the complicated headset structure, low accuracies, extended training periods, and nonstationary noises, BCI still has many challenges that should be dealt with for further facilitation of BCI technology use in daily life. In this study, a simplified synchronized hybrid BCI system is proposed for multiple command control by the electroencephalograph (EEG) signals in the motor cortex. This system can detect the single motor imagery (MI) task, single steady-state visually evoked potential (SSVEP) task, and hybrid MI + SSVEP tasks simultaneously (total ten mental tasks) via 2 EEG channels with high accuracy. The fast independent component analysis algorithm is employed to hybrid signals for obtaining clear EEG signals resulting from denoising. Feature extraction is performed by the wavelet transform, which is extracted by the features in the frequency and time domains. Furthermore, a four-layer convolutional neural network (CNN) is used as a classifier to distinguish different mental tasks. Finally, the hybrid MI + SSVEP system with a simple structure achieves a high accuracy of 95.56%. Additionally, the single MI-based and the SSVEP-based BCI system obtain the classification accuracy of 90.16% and 93.21%, respectively. Experimental results indicate that the synchronized hybrid BCI system could achieve multiple command control with a simple structure. In comparison with the single MI-based and the SSVEP-based BCI system, the hybrid MI + SSVEP BCI system shows a stable performance and higher efficiency. The proposed investigation provides a new method for the multiple command control by a hybrid BCI system. Also, the proposed BCI system offers the possibility of friendly utilization for disabled people because of its reliability, ease of use, and simplified headset structure.

Highlights

Brain-computer interface (BCI) provides a communication pathway to access and understand the neural activity in which the user’s intent is translated for control of the external device, such as computer, assistive applications, and neural prosthetics [1]
For the state visually evoked potential (SSVEP) case, the least absolute shrinkage selection operator (LASSO) and the canonical correlation analysis (CCA) algorithms are the popular classifiers to be used in BCI areas
In order to verify the advantage of the convolutional neural network (CNN) for the classification, we employ the same dataset which has been processed by FastICA. e results exhibit that the classifier’s performance directly influences the accuracy of the system

Summary

Introduction

Brain-computer interface (BCI) provides a communication pathway to access and understand the neural activity in which the user’s intent is translated for control of the external device, such as computer, assistive applications, and neural prosthetics [1]. In the case of the hybrid BCI with multiple types, different types could provide the brain information in various aspects, in which fNIRS offers the information for hemodynamic metabolism, and EEG delivers the message of the neuron spike. E hybrid BCI system of multiple brain signals with a single BCI type shows superiority due to its same sample rate and device [9, 10]. In this case, the typical brain activities for a single EEG type include motor imagery (MI) [11, 12], steady-state visually evoked

Methods

Results

Conclusion