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Only received raw EEG data

Posted: Wed Mar 24, 2021 3:16 pm
by darsool
Hello,

I am using mind monitor for a research project, and I noticed post-meditation that Mind Monitor recorded only raw EEG data, and did not apply the FTT to it. It received battery, gyro and accelerometer data as well, but it looks like there must have been a poor fit for the headband; horseshoe had only the black ring on it. Can these data be transformed easily into the the FTT?

Re: Only received raw EEG data

Posted: Wed Mar 24, 2021 3:37 pm
by James
You are correct, the HeadBandOn data column is all 0(False).
Interaxon's algorithm which calculates the Absolute values only does so once the headband has been detected on the head.

You can do your own FFT's on the data, but you would need full 256Hz EEG to do that by changing the "Recording Interval" in settings to "Constant". You can't do anything with the attached data set as it's 1Hz.

Looking at the data, your signal is terrible on TP9/TP10 and ok on AF7/AF8.
As the signal on AF7/AF8 is good, HeadBandOn should be 1(True), so it's likely that the grounding sensor pads were also not making contact. You need to have the ground signal from the center three pads for HeadBandOn to trigger. I'd give them a gentle scrub to clean them.

Re: Only received raw EEG data

Posted: Mon Mar 29, 2021 11:31 am
by darsool
Hi James,
Thanks for your reply. It looks like the headband has this issue on multiple people. I've tried scrubbing the sensors with a cloth and with alcohol wipes, which I was assured was acceptable to use on them, it seems to work half of the time. Is the Muse 2 this temperamental, or do I just have a temperamental device to begin with?

Re: Only received raw EEG data

Posted: Mon Mar 29, 2021 12:30 pm
by James
It's certainly a common issue, but I think it's just something to be expected, rather than a fault with the Muse.

Skin flakes off as new skin grows underneath. It's not pleasant to think about, but you're constantly shedding dust, and with sweat mixed in, that's going to stick to the Muse and get it dirty over time.

If you're still having issues after cleaning the Muse, try cleaning the other side of the connection; your forehead. A gentle exfoliating rub with a damp face cloth will remove any dead skin, improve the connection and make you feel fresh and clean ;-)