title: A DAQ-device-based continuous wave near-infrared spectroscopy system for measuring human functional brain activity.
abstract: In the last two decades, functional near-infrared spectroscopy (fNIRS) is getting more and more popular as a neuroimaging technique. The fNIRS instrument can be used to measure local hemodynamic response, which indirectly reflects the functional neural activities in human brain. In this study, an easily implemented way to establish DAQ-device-based fNIRS system was proposed. Basic instrumentation components (light sources driving, signal conditioning, sensors, and optical fiber) of the fNIRS system were described. The digital in-phase and quadrature demodulation method was applied in LabVIEW software to distinguish light sources from different emitters. The effectiveness of the custom-made system was verified by simultaneous measurement with a commercial instrument ETG-4000 during Valsalva maneuver experiment. The light intensity data acquired from two systems were highly correlated for lower wavelength (Pearson's correlation coefficient r = 0.92, P < 0.01) and higher wavelength (r = 0.84, P < 0.01). Further, another mental arithmetic experiment was implemented to detect neural activation in the prefrontal cortex. For 9 participants, significant cerebral activation was detected in 6 subjects (P < 0.05) for oxyhemoglobin and in 8 subjects (P < 0.01) for deoxyhemoglobin.
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China ; Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China.
authors.forename: Gang
authors.identifier: 0000-0003-3408-0558
authors.initials: G
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China ; Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Information Science and Engineering, Yanshan University, Qinhuangdao 066004, China.
authors.forename: Duan
authors.identifier: 0000-0001-9102-0741
authors.initials: D
authors.lastname: Li
authors.affiliation: School of Electronic Information and Control Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Liu
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D059906:Neuroimaging / Q000295:instrumentation / Q000379:methods*; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation / Q000379:methods*; D018709:Statistics, Nonparametric; D014636:Valsalva Maneuver / Q000502:physiology
chemical_list: D006454:Hemoglobins; C100003:deoxyhemoglobin