Toward a reliable PWM-based light-emitting diode visual stimulus for improved SSVEP response with minimal visual fatigue

The Journal of Engineering

Surej Mouli¹  Ramaswamy Palaniappan¹ 

[1] Data Science (E-Health) Research Group, School of Computing, University of Kent, Medway, Chatham, Kent, UK

关键词: flashing visual stimulus;    high information transfer rate;    minimal visual fatigue;    steady-state visual evoked response;    visual-based diagnosis;    brain–computer interfacing;    reliable PWM-based light-emitting diode;    eye fatigue;    improved SSVEP response;    electroencephalogram data;    gaze control;    precise pulse-width modulation;   

DOI  :  10.1049/joe.2016.0314

学科分类：工程和技术（综合）

来源: IET

【 摘 要 】

Steady-state visual evoked response (SSVEP) is widely used in visual-based diagnosis and applications such as brain–computer interfacing due to its high information transfer rate and the capability to activate commands through simple gaze control. However, one major impediment in using flashing visual stimulus to obtain SSVEP is eye fatigue that prevents continued long-term use preventing practical deployment. This combined with the difficulty in establishing precise pulse-width modulation (PWM) that results in poorer accuracy warrants the development of appropriate approach to solve these issues. Various studies have suggested the usage of high frequencies of visual stimulus to reduce the visual fatigue for the user but this results in poor response performance. Here, the authors study the use of extremely high duty-cycles in the stimulus in the hope of solving these constraints. Electroencephalogram data was recorded with PWM duty-cycles of 50–95% generated by a precise custom-made light-emitting diode hardware and tested ten subjects responded that increasing duty-cycles had less visual strain for all the frequency values and the SSVEP exhibited a subject-independent peak response for duty-cycle of 85%. This could pave the way for increased usage of SSVEP for practical applications.

【 授权许可】

CC BY