A Dry Electrode Cap and Its Application in a Steady-State Visual Evoked Potential-Based Brain–Computer Interface

Miao Yuan,Lu Jiang,Lihua Xing,Yamin Li,Chunrong Wei,Yijun Wang,Hongda Chen,Xiaoshan Huang,Yuanyuan Liu,Xiaowei Yang,Li Zheng,Xiaoting Wu,Weihua Pei,Zhiduo Liu,Xiao Xing

doi:10.3390/electronics8101080

Abstract

The wearable electroencephalogram (EEG) dry electrode acquisition system has shown great application prospects in mental state monitoring, the brain–computer interface (BCI), and other fields due to advantages such as being small in volume, light weight, and a ready-to-use facility. This study demonstrates a novel EEG cap with concise structure, easy adjustment size, as well as independently adjustable electrodes. The cap can be rapidly worn and adjusted in both horizontal and vertical dimensions. The dry electrodes on it can be adjusted independently to fit the scalp as quickly as possible. The accuracy of the BCI test employing this device is higher than when employing a headband. The proposed EEG cap makes adjustment easier and the contact impedance of the dry electrodes more uniform.

Highlights

The brain–computer interface (BCI), especially the electroencephalogram (EEG)-based non-invasive BCI, is a promising human–computer interaction technology [1]
The statistical significance test of the accuracy between classification accuracy with a 2 s data length can reach to 0.9753 with the proposed EEG cap, higher the EEG cap and the headband indicated that the cap and the headband have a significance difference than 0.9575 with the headband for 12 subjects
The statistical significance test of the accuracy between (p = 0.00028), namely, the EEG quality, or signal-to-noise ratio of EEG of the proposed cap was better the EEG cap and the headband indicated that the cap and the headband have a significance difference than that of the headband

Summary

Introduction

The brain–computer interface (BCI), especially the electroencephalogram (EEG)-based non-invasive BCI, is a promising human–computer interaction technology [1]. The EEG signal acquisition system plays a significant role in BCI technology. The EEG acquisition system is composed of electrodes, a cap or headset, amplification circuits, and a wire or wireless transmission module. A ready-to-use EEG cap is a decisive technology if BCI will be extended from the laboratory to practical applications. Dry electrodes need no gel nor cleaning after use. It might be an ideal EEG sensor device if it had electrical characteristic as good as a wet electrode [2,3,4]. Many methods are used to improve the convenience and the electrical characteristics of dry electrode systems. Few dry EEG caps can behave like their wet opponent [5,6].

Methods

Results

Conclusion