A Brain-Computer Interface Based on Bilateral Transcranial Doppler Ultrasound

Andrew J B Myrden,Tom Chau,Azadeh Kushki,Ervin Sejdić,Anne-Marie Guerguerian

doi:10.1371/journal.pone.0024170

Abstract

In this study, we investigate the feasibility of a BCI based on transcranial Doppler ultrasound (TCD), a medical imaging technique used to monitor cerebral blood flow velocity. We classified the cerebral blood flow velocity changes associated with two mental tasks - a word generation task, and a mental rotation task. Cerebral blood flow velocity was measured simultaneously within the left and right middle cerebral arteries while nine able-bodied adults alternated between mental activity (i.e. word generation or mental rotation) and relaxation. Using linear discriminant analysis and a set of time-domain features, word generation and mental rotation were classified with respective average accuracies of 82.9%10.5 and 85.7%10.0 across all participants. Accuracies for all participants significantly exceeded chance. These results indicate that TCD is a promising measurement modality for BCI research.

Highlights

Brain-computer interfaces (BCIs) translate mental activity into control signals for external devices, thereby providing their users with movement-free communication and control channels [1]
Feasibility of a transcranial Doppler ultrasound (TCD)-based BCI This study investigated the potential of TCD as the measurement modality for a BCI
We demonstrated that two types of mental activity can be classified with greater than 80% accuracy on the basis of changes in cerebral blood flow velocity

Summary

Introduction

Brain-computer interfaces (BCIs) translate mental activity into control signals for external devices, thereby providing their users with movement-free communication and control channels [1]. There has been a great deal of research into the usage of BCIs as means of communication and control for individuals with severe and multiple disabilities [5,6]. BCI systems offer these individuals the potential to achieve some degree of independence and control over their environments. BCI control bypasses the muscular system entirely and may allow communication even for those who are completely locked-in due to conditions such as stroke or amyotrophic lateral sclerosis (ALS) [7]. BCIs have been used to generate text communication based on measuring brain responses to visually presented letters on a computer screen [8]

Methods

Results

Conclusion