Periodic noise

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Joined: Wed Aug 03, 2022 2:37 pm

Periodic noise

Post by joseluisblues »

Hello community,

We are using the Biosemi ActiveTwo 64 channel system.
Since a while ago we detected a strange periodic noise (~0.5 Hz) infiltrating the signal (for external and EEG channels).
See a picture of the noise below.
EEG_noise_0.5_Hertz.jpeg (48.06 KiB) Viewed 67 times
We performed the bucket test and we didn't find any malfunctioning electrode.
The noise is also reflected in the blinking of a blue light in the front of the AD-box (labeled "CM in range") next to the power light. We noticed that by moving and stretching the wires we can briefly eliminate the noise. However, the noise reappears very easily when leaving the wires in a slightly different configuration (see noise in the image attached).

Can anyone advise us on what might be the source of this noise and how we might go about correcting it?
Any pointers would be really appreciated.


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Re: Periodic noise

Post by Coen »

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