title: Classification of functional near-infrared spectroscopy signals corresponding to the right- and left-wrist motor imagery for development of a brain-computer interface.
abstract: This paper presents a study on functional near-infrared spectroscopy (fNIRS) indicating that the hemodynamic responses of the right- and left-wrist motor imageries have distinct patterns that can be classified using a linear classifier for the purpose of developing a brain-computer interface (BCI). Ten healthy participants were instructed to imagine kinesthetically the right- or left-wrist flexion indicated on a computer screen. Signals from the right and left primary motor cortices were acquired simultaneously using a multi-channel continuous-wave fNIRS system. Using two distinct features (the mean and the slope of change in the oxygenated hemoglobin concentration), the linear discriminant analysis classifier was used to classify the right- and left-wrist motor imageries resulting in average classification accuracies of 73.35% and 83.0%, respectively, during the 10s task period. Moreover, when the analysis time was confined to the 2-7s span within the overall 10s task period, the average classification accuracies were improved to 77.56% and 87.28%, respectively. These results demonstrate the feasibility of an fNIRS-based BCI and the enhanced performance of the classifier by removing the initial 2s span and/or the time span after the peak value.
authors: Department of Cogno-Mechatronics Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735, Republic of Korea. Electronic address: noman@pusan.ac.kr.
authors: Noman
authors: N
authors: Naseer
authors: Keum-Shik
authors: KS
authors: Hong
mesh_terms: D000328:Adult; D062207:Brain-Computer Interfaces; D016002:Discriminant Analysis; D007839:Functional Laterality; D006801:Humans; D007092:Imagination; D008297:Male; D009068:Movement; D019265:Spectroscopy, Near-Infrared / Q000706:statistics & numerical data*; D013997:Time Factors; D014953:Wrist / Q000098:blood supply / Q000502:physiology*; D055815:Young Adult
keywords: Brain–computer interface (BCI); Functional near-infrared spectroscopy (fNIRS); Wrist motor imagery