BioSemi.nl

EDFbrowser, a new free opensource multiplatform viewer.

- supported fileformats: EDF, EDF+, BDF, Nihon Kohden*

- supports montages

- annotations

- precise measurements by using crosshairs

- zoomfunction by drawing a rectangle with the mouse

- shows signals from different files at the same time

- built in EDF/EDF+/BDF to ASCII converter

- built in Nihon Kohden to EDF+ converter (including annotations)

- built in EDF/EDF+/BDF compatibility checker

- available for Linux and Windows

You can download it here:

http://www.teuniz.net/edfbrowser

version 1.03 changes:

- improved printing resolution

- solved an issue with printermargins and fonts thanks to new printerframework in Qt 4.4.x

- added option to "print" to an EDF or BDF file
now you can extract one or more signals and write it to a new EDF file
or you can combine signals from several files into one new EDF file
printing to a BDF file is supported as well
read the manual for the details

- added option user defined displaytime (pagetime)

- added option jump to end of recording

- dropped the maximum datarecordblocksize of 61440 bytes
requirement for EDF+ files
from now on EDFbrowser will accept EDF+ files with
larger blocksizes

http://www.teuniz.net/edfbrowser/

Best regards,

Teunis van Beelen

Hi Teunis,

nice program, I like it a lot. However, the combination of the status signal and skin response signal is currently not possible as they do not have the same physical dimension (as your program says). Skin response is recorded in nS by the Biosemi system, now it would be quite great if I could export it into text or even csv together with my decimal trigger values, so that I could do further calculations in excel or some other package. I know it is open source and time is valuable, so please do not see these questions as requests but rather general inquiries of interest:

Do you think that it would be possible

1) to change status values to decimal?
2) to export GSR and status together?

Thanks for your great work!

I'm glad to hear that you like the program.

Can you send me a (small) example-file so that I can have a look at it?

Generally, changing the physical dimension of a signal in EDF/BDF is very tricky because then you need to adjust the
physical maximum and minimum as well.
You can use a hex-editor to change these items in the header of the file but you will need a very good understanding
of the EDF/BDF fileformat.

EDFbrowser has a multi-channel, multifrequency EDF/BDF to ASCII export function.
You can find it in the tools menu. There is a description about this function in the manual.

I hope this will help.

Hi,

First, thank you for all of the time and work that went into developing edfbrowser.

I am probably making a very basic mistake or misinterpretation, but have been unsuccessful in loading any of my .bdf files.
1. I did use your "check EDF/BDF compatibility" function and the files are being listed as compatible.
2. File > Open >select all (of the 32 electrodes) > add signals
a) If I then click "close", none of the electrodes are selected
b) If I click "display combination", I get one of two responses:
1. the list of channels scroll across the middle of the screen
(Fp1 + AF3 + ....) and I get one EEG signal across the
screen that appears to be all of the electrode data
combined into one signal OR
2. the list of channels appear down the left side of the screen
and I get one EEG signal across the screen that appears to
be all of the electrode data combined into one signal
c) at this point the program freezes ("not responding").

Any suggestions would be greatly appreciated!

Sincerely,
P. Sorensen

[quote="watermaze"]
I am probably making a very basic mistake or misinterpretation, but have been unsuccessful in loading any of my .bdf files.
1. I did use your "check EDF/BDF compatibility" function and the files are being listed as compatible.
2. File > Open >select all (of the 32 electrodes) > add signals
a) If I then click "close", none of the electrodes are selected
[/quote]

Probably, your signals have a large DC-offset. Try the following procedure:

File->Open->select all->add signals->close

then adjust the amplitude and DC-offset:

Amplitude->Fit to pane

Now you should see the signals on your screen.

Let me now the results.

Regards,

Teunis

Hi Teunis,

You were right - I followed your instructions and can view all of the electrode channels.

I tried to then export to ASCII but get the error message:

Error when writing to outputfile curing conversion

The program does create the files (i.e., JohnApr2208_annotations; JohnApr2208_data; JohnApr2208_header; JohnApr2208_signals) but the files are empty.

I get the same error message when I attempted to print to bdf (as I removed some channels from the files)

Error while writing to outputfile.

Sorry to keep bothering you - I really appreciate your help.

Sincerely,
P. Sorensen

[quote]Error when writing to outputfile curing conversion[/quote]

Normally, this happens when there is no disk-access or when the disk is full.
Because there are some files generated, disk-access looks ok. So, it looks like there's not enough space left on the harddisk.
Keep in mind that ascii-files can be 10 times bigger than the source-file.

Which operating-system do you use? The windows-version of EDFbrowser is designed for windows 2000 and XP. Win95, 98, ME are not supported and will probably fail.
It's not tested with Vista yet.

If the problem persists, can you send me a (small) file which causes this problem so that I can investigate it?

version 1.04 changes:

- added an ASCII to EDF format converter


http://www.teuniz.net/edfbrowser/


Best regards,

Teunis van Beelen

Hi Teunis,

I have download EDFbrowser, is it can be used for analyzing GSR data from preprocessing to statistics?
I'm new in GSR data analysis and confused about it, could you tell me some information about it? Thanks in advance!

Qian

Hello Qian,

EDFbrowser is more a general viewer. It has some filters, tools and converters but nothing particular for GSR.

Regards,

Teunis