Introduction to Near-Infrared Spectroscopy
Absorption & scattering contrast
Physiological contrasts
Functional contrasts
fNIRS history
Light propagation in biological tissue
Quantifying hemoglobin changes:
Modified Beer-Lambert law
NIRS modalities
Cerebral Oximetry
CW-, FD-, & TD- NIRS
Broadband
DCS
Imaging
2D mapping = topography
3D reconstruction = tomography
Atlas head model
Challenges
Sensitivity to brain
Systemic physiology contamination
Motion artifacts
More Challenges
Differential path-length & partial volume error
Potential for hemoglobin crosstalk
Focal changes, spatial resolution
Additional consideration
Use in clinical applications
Use in neuroscience applications
Devices choices
SNR & Dynamic range
Short separation channels
High density
Safety
ANSI standards
