Re EEG

[Dr. Jörg Schmitz]

Please, be careful with DIY-EEG (and ECG and EMG too) !!!!!!!!!!!

I worked on this topic years ago on the university.
(We recorded EEG and correlated the signals to other biological
signals, like heart rate, breathing and so on.)
Recording a normal EEG is not so complicated. 
The problem is, every movement you do, will influence the 
EEG significantly, because your brain produces microvolts, 
but your muscles millivolts.
The other problem : you have to filter special frequencies, produced
from the brain. The most important frequencies are on a very low
band, so you will also get a lot of artifacts.
Building a system used by the NASA and AirForce, to fly an aircraft
only by thinking will cost you a lot lot lot of money. Then it will
work.

It would be much easier, to record EMG (myography). This is 
not possible with the upper extremities, while you are playing 
other instruments. But for example, if you use 2 electrodes
on the lower leg, the contracting the muscle will give you
a signal. You have to use an envelope follower, to transform
the high frequency signal into a CV.
With a little training, the contraction force will produce a good
CV for you.

j.s.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/ms-tnef
Size: 2527 bytes
Desc: not available
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/19980910/ae2b303d/attachment.bin>