Problem importing EDF file from Somnomedics PSG system

[neurodjami]

Hello everyone,
I have an issue importing an EDF file recorded with a Somnomedics polysomnography system.

The problem
When I try to import this EDF file into Brainstorm (via “Import MEG/EEG: EDF, BDF, GDF, SET”), the imported file appears empty in Brainstorm:
• no visible channels,
• no data,
• no time series.
There is no error message — just an empty dataset.

What I can do
• The EDF file opens correctly in the Somnomedics software (Domino) and external software for EEG Data (Polyman).
• I can see all channels and the full recording.
• A colleague successfully loaded the same EDF using MNE-Python (mne.io.read_raw_edf()),
and was able to plot all channel time courses without problems.
→ So the file itself is valid and not corrupted.

My questions
1 Does Brainstorm fully support EDF files exported by Somnomedics PSG systems?
2 Are there known issues with channel names, channel types, or EDF header structure from this manufacturer?
3 Is there a recommended way to preprocess or convert such EDF files so Brainstorm can read them?
4 Would it help if I provide a short EDF snippet for testing?
Additional info
My colleague suggested that Brainstorm might not recognize certain EDF header fields used by Somnomedics.
He proposed a workaround (loading with MNE, redefining channel types, exporting as FieldTrip format), but before doing that I wanted to check whether Brainstorm has built-in support or an existing solution.

Thank you very much in advance!
Dzhamilia

[Raymundo.Cassani]

@neurodjami

1 Does Brainstorm fully support EDF files exported by Somnomedics PSG systems?

Brainstorm does support EDF regardless the manufactures. Indeed, it could be that Somnomedics adds some data that interferes in the way the file is parsed in Brainstorm (as your coworkers suggested)

@neurodjami

2 Are there known issues with channel names, channel types, or EDF header structure from this manufacturer?

No as far as we are aware

@neurodjami

3 Is there a recommended way to preprocess or convert such EDF files so Brainstorm can read them?

Ideally, Brainstorm should be able to read it as EDF.

@neurodjami

4 Would it help if I provide a short EDF snippet for testing?

Yes, this will help us to identify the issue and be able to read these files directly in Brainstorm.
Can you read them without troubles nor warnings in EDFbrowser?

[edelaire]

@neurodjami

When I try to import this EDF file into Brainstorm (via “Import MEG/EEG: EDF, BDF, GDF, SET”), the imported file appears empty in Brainstorm:

We had a similar issue in our lab. The solution was to import using the format ‘EEG EDF / EDF+ FieldTrip reader (*.rec;*.edf)’ instead of ‘EEG: EDF / EDF+ (*.rec;*.edf)’.

The issue was because of the different sampling frequency of the signals inside the edf file. Also, somno tends to add space in the channel name, which was causing some issues.

Edouard