Fast Perturbation Monte Carlo simulation for heterogeneous medium and its utilization in functional near-infrared spectroscopy

Introduction: Functional near-infrared spectroscopy (fNIRS) has been broadly applied for optical brain imaging. This method is hemodynamic-based functional brain imaging relying on the measurement of the neurovascular coupling to detect changes in cerebral neuronal activities. The extra-cerebral hemodynamic changes are important contaminating factors in fNIRS measurements. This error signal can be misinterpreted as cerebral activities during fNIRS studies. Recently, it was assumed that temporal changes in deoxygenated hemoglobin concentration [HHb] was hardly affected by superficial blood flow, and it was proposed that the activation maps could be determined from [HHb] at large source-detector separation. Methods: In the current study, we measured the temporal changes in [HHb] using a continueswave fNIRS device at large source-detector separation, while superficial blood flow was stimulated by infrared lasers. A mesh-based Monte Carlo code was applied to estimate fNIRS sensitivity to superficial hemodynamic changes in a realistic 3D MRI-based brain phantom. Results: First, we simulated photon migration in a four-layered human-head slab model to calculate PPLs and fNIRS sensitivity. Then, the localization of the infrared laser inside a realistic brain model was studied using the Monte Carlo method. Finally, the changes in [HHb] over the prefrontal cortex of six adult males were measured by fNIRS at a source-detector separation of 3 cm. The results demonstrated that the relation between fNIRS sensitivity and an increase in S-D separation was nonlinear and a correlation between shallow and deep signals was observed. Conclusion: The presented results demonstrated that the temporal changes in the superficial blood flow could strongly affect HHb measurement at large source-detector separation. Hence, the cerebral activity map extracted from the [HHb] signal was mainly contaminated by superficial blood flow.

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A Study of Frontal Signals in Brain Computer Interfaces: Interpretation of EEG & FNIRS

International Journal of Scientific Research in Science Engineering and Technology ◽

10.32628/ijsrset207622 ◽

2020 ◽

pp. 136-142

Author(s):

S. Srilekha ◽

B. Vanathi

Keyword(s):

Infrared Spectroscopy ◽

Healthy Subject ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Economic Conditions ◽

Brain Computer Interfaces ◽

Functional Near Infrared Spectroscopy ◽

Computer Interfaces ◽

Rehabilitation Devices

This paper focuses on electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) comparison to help the rehabilitation patients. Both methods have unique techniques and placement of electrodes. Usage of signals are different in application based on the economic conditions. This study helps in choosing the signal for the betterment of analysis. Ten healthy subject datasets of EEG & FNIRS are taken and applied to plot topography separately. Accuracy, Sensitivity, peaks, integral areas, etc are compared and plotted. The main advantages of this study are to prompt their necessities in the analysis of rehabilitation devices to manage their life as a typical individual.

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61-LB: Use of Functional Near-Infrared Spectroscopy (fNIRS) to Assess Cognitive Effort in KATP-Related Neonatal Diabetes (KATP-NDM)

Diabetes ◽

10.2337/db20-61-lb ◽

2020 ◽

Vol 69 (Supplement 1) ◽

pp. 61-LB

Author(s):

LISA R. LETOURNEAU-FREIBERG ◽

KIMBERLY L. MEIDENBAUER ◽

ANNA M. DENSON ◽

PERSEPHONE TIAN ◽

KYOUNG WHAN CHOE ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Neonatal Diabetes ◽

Cognitive Effort ◽

Functional Near Infrared Spectroscopy

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The Use of fNIRS for Unique Contributions to Social and Affective Neuroscience

10.31234/osf.io/kygbm ◽

2019 ◽

Author(s):

Shannon Burns ◽

Matthew D. Lieberman

Keyword(s):

Infrared Spectroscopy ◽

Social Interaction ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Affective Neuroscience ◽

Functional Near Infrared Spectroscopy ◽

Psychological Experience ◽

The World ◽

And Behavior ◽

Meaningful Interaction

Social and affective neuroscience studies the neurophysiological underpinnings of psychological experience and behavior as it relates to the world around us. Yet, most neuroimaging methods require the removal of participants from their rich environment and the restriction of meaningful interaction with stimuli. In this Tools of the Trade article, we explain functional near infrared spectroscopy (fNIRS) as a neuroimaging method that can address these concerns. First, we provide an overview of how fNIRS works and how it compares to other neuroimaging methods common in social and affective neuroscience. Next, we describe fNIRS research that highlights its usefulness to the field – when rich stimuli engagement or environment embedding is needed, studies of social interaction, and examples of how it can help the field become more diverse and generalizable across participant populations. Lastly, this article describes how to use fNIRS for neuroimaging research with points of advice that are particularly relevant to social and affective neuroscience studies.

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