Filtering EMG data from GUI recording sessions
BCIStudent
UK
So, I've recorded EMG data using the OpenBCI GUI. I understand that the recorded data is in the raw form. I wanted to know what recommendations for filtering were, as I'm going to import and use the data within Matlab?
When I look at the signal from the recording session it appears noisy, but the activity is still noticeable, at the very least (see picture).
NB: I have been using the Cyton board for the recording sessions, if that helps.
Comments
Hi BCI,
Filtering is easily done within Brainflow, in various languages, including Matlab, Python, etc.
https://brainflow.readthedocs.io/en/stable/Examples.html#matlab-signal-filtering
https://brainflow.readthedocs.io/en/stable/Examples.html#python-signal-filtering
Regards, William
Your photo shows that your notch filter is off, did you try turning that on? So you in doing your own filtering of the raw recording, you will want to use BOTH a notch and bandpass.
There wasn't a noticeable difference having the notch applied or not. That's why it's off in the screenshot.
Thanks for the link to the Matlab section, what are the "DigitalFilter" settings (cutt off frequency, order etc) for the BUTTERWORTH in the 'signal filtering' example? And what is the "DigitalFilter" settings used in the 'denoising' example?
Thanks.
https://brainflow.readthedocs.io/en/stable/UserAPI.html#matlab-api-reference
Best place to ask Brainflow questions, is on their Slack. Sign up here,
https://brainflow.org/