Importing sEEG .edf Issues

[Raymundo.Cassani]

Hi @edavid,

@edavid

From what I've seen thus far, the only options are MEG/EEG or EEG import file formats; to import sEEG, I have been using the

SEEG: Deltamed/Micromed/NK/Nicolet/BrainVision/EDF

This is correct, this option will read the sEEG data with the correct format based on its extension. By using this SEEG option, Brainstorm will automatically treat the channels as sEEG, rather than EEG.

@edavid

When importing my raw edfs, I get a message from Brainstorm to convert these to continuous format.

This happens when the data is saved as EDF+D which means that the recoding is discontinuous with interruptions between consecutive data records. Is this the case with your data?

When this kind of data is imported in Brainstorm, all the data gets concatenated, and events called EDF+D Discontinuity are added to show where the data has not continuous.

@edavid

# Read .edf into raw MNE format
data = mne.io.read_raw_edf(input_file + '.edf', preload=True)

I tried the lines above with a EDF+D file that I had at hand, and similar to Brainstorm, the data is read in the continuous way. However, it seems in MNE-Python the timing of the events in discontinuous files is not properly handled.

@edavid

However, when I preprocess using MNE, the .edf files produces are obviously not continous, and no such popup window is given.

This is not what I see with my data at hand, the EDF+D is read as continuous EDF in MNE-Python, then after processed it is exported as EDF+C (continuous), and this is why once you import it in Brainstorm, it does not showed the message about being discontinuous, as it was changed in MNE-Python

@edavid

I'm wondering if there is a flag in the file that needs to be present for Brainstorm to know whether it is continuous or not? Or if there is an option to do this manually after import?

The EDF files have information in their headers to show if they are continuous or discontinuous. You can read the first 200 charcters of the file to check this. If in Linux, run in the terminal:

head -c 200 file.edf

It will show the identifier EDF+C or EDF+D

@edavid

Or, perhaps, there is another way to import the data that would be more appropriate?

Since the event timing seems better handled in Brainstorm. You could import your data and do the same pre-processing in Brainstorm without any trouble.

EDIT: Check this other post on the topic:

About EDF file read related problem

Hi Francois Do you give suggestion regarding the following message: " Warning: Interrupted EDF file ("EDF+D"): requires conversion to "EDF+C" In in_fopen_edf (line 172) In in_fopen (line 96) In import_raw (line 126) In bst_call (line 28) In tree_callbacks>@(h,ev)bst_call(@import_raw,,,iSubject) (line 596) " The above message is generated when I load .EDF file. But I see the waveform. My question is that, is above warning can show any change in my data. Best regards --Sheuli