Wearable brain-computer interfaces for everyday life based on ear-EEG

Abstract

A brain-computer interface (BCI) records and translates brain activity into digital commands. It works as a gateway between the human brain and external devices, enabling users to communicate or control environments solely with thoughts. Although it has been proven in many previous studies that BCIs can successfully interpret the users’ intentions from their neural activities acquired with electroencephalogram (EEG) with high accuracy in a wide range of applications, BCIs can be constrained by their paradigm and EEG acquisition methods which makes them unsuitable for daily life. Conventional EEG acquisition methods exhibit poor wearability, require long equipment preparation time, and can be a distraction in daily-life activities both physically and socially. This dissertation addresses the problem of the conventional EEG acquisition methods and BCI paradigms and proposes BCI systems for daily life that are based on ear-EEG, the EEG acquisition technique that measures EEG centered around the user’s ears, which is more discreet and has better wearability. We construct a wearable BCI device that utilizes ear-EEG and present ear-EEG as an alternative EEG acquisition method for two BCI paradigms that are suitable for daily life including speech imagery, an imagination of a speech or sound without actually speaking, and affective BCI that monitor a user’s emotional state. This dissertation validates the efficacy of the ear-EEG acquisition method by comparing its performance with the traditional EEG acquisition methods. We also construct an online BCI system for control using the combination of ear-EEG acquisition methods and speech imagery BCI paradigm. The results show that ear-EEG can be effectively used in the proposed BCI systems with its performance on par with the conventional method. We believe that the merits and feasibility of the ear-EEG in the proposed BCI frameworks will accelerate the development of the BCI system for daily-life use.