BioSemi.nl

Hi all

I got a question concerning the file size of bdf-files:
Or files turn out to be really big (~650 MB) due to the nature of our experiment there is no way to avoid that. Unfortunately, the algorithm we use to analyse our data relies on EEGLAB which runs out of memory - even on our strongest machine. I thought that it would help to manually cut out out the epochs and downloaded the EDF browser, but I as far as I can see, you can't cut out something in the middle of a file. Does anybody know I program which is capable of doing that or has another solution how to solve this problem?

Thanks in advance!

You can split up BDF files in smaller pieces with the FILE CROPPER utility from http://www.biosemi.com/download/Cropper.zip

You can also save the data in smaller files during recording. In the right sidebar of ActiView, select:

- File Limit in MB, set the control to the preferred size of the file parts
- Check the box: new file on limit

ActiView will now start a new file each time that the running file reaches the set limit. The number of files is indicated in the right sidebar (bottom). The files match seamlessly, no data points can be lost.

Best regards, Coen (BioSemi)

"I thought that it would help to manually cut out out the epochs and downloaded the EDF browser,
but I as far as I can see, you can't cut out something in the middle of a file."

Yes, you can. In EDFbrowser, go to Tools -> Reduce signals and or/duration.

Anotherway is File -> Print -> to BDF. This creates a new BDF file which will contain what you
see on the screen i.e. "what you see is what you get".

Read the manual for the details.