An SSVEP-Based BCI Using High Duty-Cycle Visual Flicker

NCUIR > College of Electrical Engineering & Computer Science > Department of Electrical Engineering > journal & Dissertation > Item 987654321/52033

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/52033

Title:	An SSVEP-Based BCI Using High Duty-Cycle Visual Flicker
Authors:	Lee,PL;Yeh,CL;Cheng,JYS;Yang,CY;Lan,GY
Contributors:	電機工程學系
Keywords:	BRAIN-COMPUTER INTERFACE;FREQUENCY;COMMUNICATION;STIMULATION;TOPOGRAPHY
Date:	2011
Issue Date:	2012-03-28 10:13:46 (UTC+8)
Publisher:	國立中央大學
Abstract:	Steady-state visual-evoked potential (SSVEP)-based brain-computer interfaces (BCIs) have generated significant interest due to their high information transfer rate (ITR). Due to the amplitude-frequency characteristic of the SSVEP, the flickering frequency of an SSVEP-based BCI is typically lower than 20 Hz to achieve a high SNR. However, a visual flicker with a flashing frequency below the critical flicker-fusion frequency often makes subjects feel flicker jerky and causes visual discomfort. This study presents a novel technique using high duty-cycle visual flicker to decrease user's visual discomfort. The proposed design uses LEDs flashing at 13.16 Hz, driven by flickering sequences consisting of repetitive stimulus cycles with a duration T (T = 76 ms). Each stimulus cycle included an ON state with a duration T(ON) and an OFF state with a duration T(OFF) (T = T(ON) + T(OFF)), and the duty cycle, defined as T(ON)/T, varied from 10.5% to 89.5%. This study also includes a questionnaire survey and analyzes the SSVEPs induced by different duty-cycle flickers. An 89.5% duty-cycle flicker, reported as a comfortable flicker, was adopted in a phase-tagged SSVEP system. Six subjects were asked to sequentially input a sequence of cursor commands with the 25.08-bits/min ITR.
Relation:	IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
Appears in Collections:	[Department of Electrical Engineering] journal & Dissertation

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	651	View/Open

社群 sharing

Loading...