Development of an electrooculogram-based human-computer interface using involuntary eye movement by spatially rotating sound for communication of locked-in patients

Do Yeon Kim,Chang-Hwan Im,Chang-Hee Han

doi:10.1038/s41598-018-27865-5

Do Yeon Kim, Chang-Hwan Im + Show 1 more

Open Access

https://doi.org/10.1038/s41598-018-27865-5

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Journal: Scientific Reports	Publication Date: Jun 22, 2018
Citations: 8	License type: open-access

Affiliation: Hanyang University

Abstract

Individuals who have lost normal pathways for communication need augmentative and alternative communication (AAC) devices. In this study, we propose a new electrooculogram (EOG)-based human-computer interface (HCI) paradigm for AAC that does not require a user’s voluntary eye movement for binary yes/no communication by patients in locked-in state (LIS). The proposed HCI uses a horizontal EOG elicited by involuntary auditory oculogyric reflex, in response to a rotating sound source. In the proposed HCI paradigm, a user was asked to selectively attend to one of two sound sources rotating in directions opposite to each other, based on the user’s intention. The user’s intentions could then be recognised by quantifying EOGs. To validate its performance, a series of experiments was conducted with ten healthy subjects, and two patients with amyotrophic lateral sclerosis (ALS). The online experimental results exhibited high-classification accuracies of 94% in both healthy subjects and ALS patients in cases where decisions were made every six seconds. The ALS patients also participated in a practical yes/no communication experiment with 26 or 30 questions with known answers. The accuracy of the experiments with questionnaires was 94%, demonstrating that our paradigm could constitute an auxiliary AAC system for some LIS patients.

Highlights

There are many individuals who lose normal pathways for communication
Another case study was that of a female amyotrophic lateral sclerosis (ALS) patient who had a sutured left eye to avoid double vision and was only able to move her eye vertically, who reported that the performance of a visual-based brain-computer interface (BCI) system was not as high as those of other BCI systems, based on auditory and tactile stimuli[27]
We propose a new EOG-based humancomputer interface (HCI) paradigm for the binary yes/no communication in ALS patients, which has several strengths: 1) user’s voluntary eye movement is not required, 2) high accuracy is achievable without any training session, and 3) no calibration is needed

Summary

Introduction

There are many individuals who lose normal pathways for communication. Patients with amyotrophic lateral sclerosis (ALS) are representative examples of the so-called ‘locked-in state (LIS)’ patients. P300 event-related potentials (ERP)[12,13,14,15], and steady-state visual evoked potentials (SSVEP)[12,16,17] are two of the most extensively studied electroencephalography (EEG) signals for non-muscular communications in patients with ALS12,18,19 Both BCI paradigms use visual stimuli to elicit specific brain electrical responses. Another case study was that of a female ALS patient who had a sutured left eye to avoid double vision and was only able to move her eye vertically, who reported that the performance of a visual-based BCI system was not as high as those of other BCI systems, based on auditory and tactile stimuli[27] These examples suggest that a variety of AAC systems still need to be developed to provide a specific ALS patient with the most appropriate communication options

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Conclusion