title: Estimation of Skin Blood Flow Artefacts in NIRS Signals During a Verbal Fluency Task.
abstract: The aim of this study was to clarify effects of skin (scalp) blood flow on functional near infrared spectroscopy (fNIRS) during a verbal fluency task. In the present study, to estimate the influence of skin blood flow on fNIRS signals, we conducted examinations on 19 healthy volunteers (39.9±13.1 years, 11 male and 8 female subjects). We simultaneously measured the fNIRS signals, skin blood flow (i.e., flow, velocity, and number of red blood cells [RBC]), and pulse wave rates using a multimodal fNIRS system. We found that the effects of skin blood flow, measured by the degree of interference of the flow, velocity, and number of RBCs, and pulse wave rates, on NIRS signals varied considerably across subjects. Further, by using the above physiological parameters, we evaluated application of the independent component analysis algorithm proposed by Molgedey and Schuster (MS-ICA) to remove skin blood flow artefacts from fNIRS signals.
authors.affiliation: Division of Medical Devices for Diagnoses, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan. aseiyama@hs.med.kyoto-u.ac.jp.
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Seiyama
authors.affiliation: Division of Medical Devices for Diagnoses, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.|Laboratory of Clinical Examination, Takayama Medical Clinic, Medical Corporation Taihoukai, Takayama, Japan.
authors.forename: Kotona
authors.initials: K
authors.lastname: Higaki
authors.affiliation: Division of Medical Devices for Diagnoses, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.|Laboratory of Clinical Examination, Takayama Medical Clinic, Medical Corporation Taihoukai, Takayama, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Takeuchi
authors.affiliation: Division of Medical Devices for Diagnoses, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Uehara
authors.affiliation: Laboratory of Clinical Examination, Takayama Medical Clinic, Medical Corporation Taihoukai, Takayama, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Takayama
mesh_terms: D000328:Adult; D016477:Artifacts; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
keywords: Coefficient of spatial uniformity; Functional near infrared spectroscopy; Independent component analysis; Pearson’s correlation coefficient; Verbal fluency task