Nihon Kohden .EEG to .EDF channel name change

1

Hello,

I imported NK Stereo-EEG files (.EEG) in Brainstorm, and exported them to EDF for a 3rd party toolbox. When opening the EDF there, the channel names have an "EEG " prefix, so AC1 in the original EEG file (also in Brainstorm channel files) ends up labeled as "EEG AC1" in the EDF as read by the 3rd party, which messes up downstream operations (if importing the EDF back to Brainstorm, the channel names are correct- AC1). This does not happen with the EDF+ output from EDF browser (Theunissen), but I would prefer Brainstorm output. What m file contains the code writing out to EDF files the channel name data? Why the change in name? Thank you, Oct

2

Hi Octavian,

The EDF standard suggests to indicate the channel type at the beginning of the channel label, eg. "EEG Fpz". Most acquisition software that save EDF files add the type at the beginning of the label.
Why don't you use the NK software to export to EDF?

The channel labels are defined here: https://github.com/brainstorm-tools/brainstorm3/blob/master/toolbox/io/out_fopen_edf.m#L197
Since what you want to do is not standard, I don't recommend you edit the EDF export function, you would create EDF files that might not be interpreted correctly by other programs.

Francois

3

Thank you, Francois. The problem with that NK exports its data as EDF+D, which then has to be converted to EDF+C in a 3rd party soft to be able to be read in my downstream pipeline, so I am back to square one (edf browser or other readers). If you have a suggestion how to get NK to provide EDF+C files, please let me know. Many thanks, Octavian