Box regarding to baseline correction

[Hojun Jeong]

Hello, all

I'm a novice user of this software, OpenViBE.

Now, I'm in trouble with the baseline correction after the 'stimulation-based epoching' box.

For general EEG processing, in my knowledge, It seems to be familiar to proceed with the baseline correction after epoching.

However, I cannot find the boxes related to baseline correction.

I tried to divide into two-way epoching and subtract baseline values from streamed epoch data.

BUT, I cannot find a way to subtract streamed value to constant value.

Is there any way to solve this problem?

If possible, please let me know how I can solve it.

Thank you!

[Thibaut]

HI,
There is no box who make directly a "baseline correction". It depends what you call a "baseline correction".
I'm not sure to understand but to subtract a value from a stream, you have the simple dsp box.
Thibaut

[Hojun Jeong]

Hi,

Thank you for your reply.

I'm not sure to understand but to subtract a value from a stream, you have the simple dsp box.

Actually, I try to use a simple DSP box, but I can't.

For my cases, I want to subtract baseline (power from -4 to -2 seconds from the cue) from the streamed power.

To achieve this goal, I designed the openViBE boxes as shown in an attachment.

Baseline was calculated by 'signal average' after 'stimulation based epoching'.
It makes baseline value after the stimulation time but only appears at that time.

How can I keep my baseline value and subtract them from the streamed data?

If you know about this matter, please let me know how can I deal with this problem.

Thank you

[Thibaut]

HI,
If I understood correctly. You are looking to subtract the average from a previous signal portion (which potentially is updated with each new stim) and not all the time but just on another specific portion.
In any case, if you are looking to keep an average that will be updated sometimes. There is no box that will do this to you automatically. You can create a new one for that or use a python script that takes care of keeping and updating this average.
Thibaut