Networking real-time EEG data

From: Dave (dfisher_at_pophost.com)
Date: 2002-02-26 16:23:51


On Tue, 05 Feb 2002 12:12:35 -0600, Doug Sutherland wrote:

Hi Doug--here is one of those messages I bit my tongue on earlier this month.
I was just back-tracking some because I wanted to refresh my mind on what you
wrote concerning the use of Java and this project. Then I read this:

>John, I actually do want to "send EEG over the net"
>too, because I'm a networking nut, but let's be honest
>and say that this is of little practical value. Why
>would someone really want to do this in real-time?
>It does make sense that data can be sent around, but
>we could just record a session in a file and then
>transport the file after the session. Me being able
>to watch your waves rolling in as they happen would
>be one of those "cool!" things, but what is the real
>value of it? Anyone? Anyone? Bueller? Bueller? <g>

This is most definitely in my plans, albeit further down the line. But I need
to design the system now in such a way as to easily accomodate this. I want to
do some group work where several people are united in common purpose. It could
certainly make a pretty incredible "couples retreat" for people who wanted to
work on their relationship and bring about a true "meeting of the minds." Or
perhaps people want to explore healing or paranormal phenomena together. The
uses for such a tool that could reflect back to each other our "group state"
using biofeedback modalities (EEG, skin conductance, etc.) are vast, as well as
exciting!

And the "kewl factor" would just be a side benefit. :)

>I have actually tested RMI over 10,000 miles and
>it works great, but again ONLY within a certain
>problem space. With EEG we are talking about a
>lot of data, and a stream of data. So for remote
>sending, assuming there really is a need for this
>in real time (and I doubt there is), RMI may not
>work well, my gut fell is that it won't. A better
>approach would probably be plain ole TCP sockets.

TCP might even hold more overhead than is useful for real-time EEG data. It
might depend on the latency of the various connecting sites, but even locally
we are talking a lot of overhead for a reliable byte-stream connection. My
initial thoughts are to use real-time streaming methods (UDP datagrams) such as
are used with video and sound. While this approach does not guarantee the
transmission of all the data, it is much faster with less overhead. And, on a
local network (which is what I would consider a more realistic use), I don't
think data loss is going to be an issue.

But first things first... we need a foundation to build upon.

Dave.



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