From: psytrix_v_at_yahoo.com
Date: 2001-06-29 12:48:35
Hi,
The general idea seems good - there are some questions about it .
The muscles are spread out the body and only one reference maybe
would not be enough. Neck's muscles may cause so EEG noise as
eyes' muscles (eg masseter x rect. externalis) .
Therefore in professional equipment the ground electrodes are
located at the lowest places of skull like that between FP1 and FP2
( but here also the noisy frontal muscle activity remains ).
The usual lowpass cut points are 15,30,50,60,75 or 100 Hz and
would be good to have one in the openeeg -
( like an extra for the BASIC openEEG model ? ) Not all filtering
processes can be done by SW without causing relevant distortion in
the background information ,
Regards to all
Waldemar
> Hi,
>
> An idea has crossed my mind: what if using a rate of 256
samples/sec and a
> freq band DC to 100 Hz (lowpass point here) and also using a
reference
> channel for detecting noises (like muscle impulses, radio freq,
50/60 Hz
> buzz, etc.) and subtract it in the amplifier section.
> Lovass Laszlo
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