is Cyton LSL stream typical EEG signal representation?

Prageethda

I am using cyton board with 8 channel and the open bci gui version in 5.0.2. when i read the lsl stream and plot the channel data it consist signal wave like periodic sign wave. I didn't enable filters given by GUI for get raw eeg signals(time series). I used python pylsl library for acquire data and below is my code.

the framerate is given as 250Hz and for each iteration get 8 channel data
when i plot my channel data it is plotted like below, and it does not feel like raw eeg data.

what can be the issue here?

wjcroft

Prageethda, hi.

Raw Cyton data has a DC offset. This is easily removed with your own high pass or bandpass filter.

https://openbci.com/forum/index.php?p=/discussion/201/large-millivolt-data-values-fbeeg-full-band-eeg

So if you had just pre-filtered with the GUI settings, that would be another way to go.

William

Prageethda

@wjcroft hi.

@wjcroft said:
Prageethda, hi.

Raw Cyton data has a DC offset. This is easily removed with your own high pass or bandpass filter.

https://openbci.com/forum/index.php?p=/discussion/201/large-millivolt-data-values-fbeeg-full-band-eeg

So if you had just pre-filtered with the GUI settings, that would be another way to go.

William

I applied filtered of GUI settings and turn on the filter on LSL settings. But still i got the same signal. What can be the reason.? Is it a bug in GUI?