Re: number of electrodes

What applications did you have in mind?

Medically, 256+ channel EEG systems may aid in detection of seizure focal
points, though this could also be argued as being overkill. The spatial
accuracy of an EEG recording is limited by many factors, not in the least
smearing of the signal by the skull, CSF, and other obstacles between the
electrode and actual neurons in the brain. You should also look into the
inverse problem.

QEEG (and very occasionally BCI) can use up to 256 channels. I have never
seen nor heard of a 512 channel EEG system or greater ­ I would imagine
these would be rare, if they do exist.

Cheers,
John

From:  Raj Mellacheruvu <[email protected]>
Reply-To:  "Discussion of EEG hardware, software, training protocols, NFB
theory - for developers and users." <[email protected]>
Date:  Wed, 25 Feb 2015 22:38:52 +0000
To:  John Ruelas <[email protected]>, "[email protected]"
<[email protected]>
Subject:  Re: [Openeeg-list] number of electrodes

 
Thanks John.
 
Appreciate the response.
 
If price were a non-issue, do you think there is value in having more
electrodes? Arbitrarily picking a number here, say a thousand? (assuming we
are able to physically place that many electrodes on the cranium). I'm
wondering if the real limitation is our brain mapping knowledge. i.e., brain
mapping granularity is very coarse at this point and we haven't mapped it to
that many regions yet?
 
Thanks,
Raj
 
 

From: John Ruelas [mailto:[email protected]]
Sent: Wednesday, February 25, 2015 4:25 PM
To: Raj Mellacheruvu
Subject: RE: [Openeeg-list] number of electrodes
 
Price. Price will increase in an almost linear correlation with channel
count.

 

Also, certain projects may only require, say, 24 channels, making the need
for a 48 or 64 channel system overkill. For this reason, also, some EEG
systems are stackable - i.e. one 24 channel system stacks on top of another
and both systems integrate to form a 48 channel system. This way a
researcher with the need for only 24 channels may purchase one board, those
with a need for 48 channels can purchase two, etc...

 

Cheers,

John

 

P.S. There are many EEG systems that support more than 24 channels, they may
be more difficult to find, and the price may be significantly higher than
smaller systems.
 

-------- Original message --------

From: Raj Mellacheruvu

Date:02/25/2015 3:22 PM (GMT-06:00)

To: [email protected]

Subject: [Openeeg-list] number of electrodes

 

Hello There,
 
I am new to this mailing list and not sure if my question is appropriate
here. 
 
Does anyone know why EEG systems have up to 24 electrodes and not more? what
is the real limitation? Is it electronics?
 
Thanks,
Raj
 
----------------------------------------------------------------------------
-- Dive into the World of Parallel Programming The Go Parallel Website,
sponsored by Intel and developed in partnership with Slashdot Media, is your
hub for all things parallel software development, from weekly thought
leadership blogs to news, videos, case studies, tutorials and more. Take a
look and join the conversation now.
http://goparallel.sourceforge.net/__________________________________________
_____ Openeeg-list mailing list [email protected]
https://lists.sourceforge.net/lists/listinfo/openeeg-list Go to the above
address to change your subscription options, e.g unsubscribe.

------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the 
conversation now. http://goparallel.sourceforge.net/