Skip to content

Optode separations

Jump to bottom
Thomas Vincent edited this page Jul 24, 2018 · 1 revision

Distances between sources and detectors involved in the same channels can be used to:

  • evaluate a montage while planning an experiment
  • filter channels where separation is too long or too close
  • inform MBLL

Main process

This process is available in NIRS > Compute separations. It takes NIRS data as input and compute all channels separations based on the channel definition. It takes no additional parameters.

The output is a map of separation distances in centimeters.

Here are the separations for the finger tapping data set:

separation_tapping

Compute function

The core function can be called via:

separations = process_nst_separations('Compute', ChannelDefs);

where:

  • ChannelDefs is the channel descriptions as loaded by brainstorm (cf db_template('channeldesc'))
  • separations is a column vector (nb_channels x 1)

Important: output unit of the Compute function is the same as in the channel definition (meters). This is different from the output of the process which is in centimeters (better for display of NIRS channels)

Clone this wiki locally