Tutorial not working with real accuisition server

Working with OpenViBE signal processing scenarios and doing scenario/BCI design
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neuropacabra
Posts: 2
Joined: Fri Sep 02, 2016 4:26 pm

Tutorial not working with real accuisition server

Post by neuropacabra »

Hello, what I am trying is to change generic accuisition server to Biosemi ActiveTwo server and keep the rest of tutorial neurofeedback paradigms - voxel visualization. I don't know why it doesnt work since I can plot signal in real time and see channel labels. I simply switch these and it doesn't work. Even in other paradigm for 2D a 3D topography.

Can you please tell what I am doing wrong? Is it sometnig like channel localization? I haven't found any useful infomration on web.

Best regards,
Michael

jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: Tutorial not working with real accuisition server

Post by jtlindgren »

Hi, does it print any warnings or errors? Generally you need to have the channel localization information exactly matching the channels you get from your device. The channel localization file is just a text file, you can make a copy of the file used in the tutorial scenarios' channel localization reader box and modify it: in the file, you specify name of each channel and its x,y,z coordinates. Next, make the channel localization reader box use your new file.


Cheers,
Jussi

neuropacabra
Posts: 2
Joined: Fri Sep 02, 2016 4:26 pm

Re: Tutorial not working with real accuisition server

Post by neuropacabra »

Hi, thank you for you kind help!

It doen't give any errors. I am pretty desperate with it (I try to get this thing working for months now).

I have Biosemi ActiveTwo 64 channel EEG (for OpenVibe I use only 32 channels) with Fs = 2048 Hz, without any EOG and ECG channels. I have official channel localization file from Biosemi (see attachement) so I changed values of OpenVibes cartezian file to this one to fit.

Then I build regular paradigm for raw and filtered signal inspection in OpenVibe and everything is fine (channels have names and signal is more or less ok). But using 2D topogrpahy still doesn't work at all. I put my modified file in channel localization box. See my files in attachement. I guess it could be some problem with CMS and DRL channels which are reference in Biosemi.

Biosemi official coordinates of channels: http://www.biosemi.com/download/Cap_coords_all.xls
Attachments
biosemi_channel_localization.txt
Biosemi localization files (modified OpenVibes original file)
(5.53 KiB) Downloaded 294 times
biosemi_2d_topography.xml
This is my 2d topography file
(21.57 KiB) Downloaded 329 times

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