Functional near-infrared imaging

Jump to navigation Jump to search


fNIR stands for functional near-infrared imaging. fNIR is a spectroscopic neuro-imaging method for measuring the level of neuronal activity in the brain. The method is based on neuro-vascular coupling, that is, the relationship between metabolic activity and oxygen level (oxygenated hemoglobin) in feeding blood vessels.

There are three types of fNIR:

  • CW - continuous wave - In this method, infrared light shines at the same intensity level during the measurement period. The detected signal is lower intensity static signal (dc valued)
  • FD - frequency domain - In this method, input signal is modulated sinusoid at some frequency and detected output signal has changes in amplitude and phase.
  • TR - time resolved - In time resolve spectroscopy, a very short pulse is introduced to measured and the pulse length is usually on the order of picoseconds. The detected signal is usually a longer signal and has a decay time.

External links

See also

Template:WS