Re: Using modularEEG to acquire ERG data

Hi Ian

I know of EOG but have not come across ERG.
So you have a professional amplifier with limited software capability?

I know that the EOG has DC components and one therefore would like a DC
amplifier for EOG applications.  EOG also has a higher bandwidth
requirement than EEG.  How does ERG compare?  Basically one needs to know
this:

1. What is your bandwidth requirement (do you need to work from 0Hz i.e.
DC?)
2. How many channels do you need?
3. Do you need concurrent sampling with zero sampling skew ( a lot of EMG
work has this requirement)

You could modify the openEEG amp quite easily for slightly lower gain.  You
could also increase the sampling rate and the bandwidth if you
only need/use 2 channels.  OpenEEG as well as many other cheap amplifiers
use multiplexed ADCs which produce lots of sampling skew... so concurrent
sampling is not possible on those.

If you had a 16-bit EEG amp that would be good.  OpenEEG's 10-bit
resolution is a bit low, so you would need to adjust the latter's gain, so
as to obtain optimum dynamic range for your application.  But that should
is easy.

Rather than to dump your current amplifier, I would suggest trying to use
it with different software.  There are 4 possibilities I could think off.

1. Larry Janow is hopeless with BioExplorer support, so asking him to
develop a driver for your amplifier is useless.  Instead, you or someone
else could write a protocol translator, a program that runs on your PC to
intercept your current amplifier's protocol, translates and parses it, into
a different protocol that BE understands.  Many years ago I wrote such a
bridge program to allow data from the Wild Divine "Stone" (SCL and HRV
data) to be read by BioExplorer.   It is messy and far from ideal.  I would
not really recommend this route, but I do mention this as a possibility.

2. You could supply the protocol definition to Jarek Foltynski who would
most likely agree to write a driver for BioEra.  BioEra is more powerful
than BioExplorer, but much more difficult to use.   You would also have to
buy BioEra for about $300USD.  Jarek would prefer to get an amplifier for
testing purposes, but I don't think that is a strict necessity.

3. You could develop your own driver (or ask someone else to do so) for
openVibe (open source).

4. You could perhaps use Chris Veigl's BrainBay which is also open source.
Again you would need to develop a driver, or get someone else to help with
that.  I don't really know BrainBay, not sure if it had sufficient
capability for your application.

You can normally place a snooper onto RS232 lines or, if your amplifier is
USB interfaced, run a software snooper, capture some raw data and reverse
engineer the protocol.  I reverse engineered the QDS 8-channel protocol
(which is supported by BE) without ever laying a hand (or eye) on QDS
hardware.  A friend simply connected his QDS to BioExplorer and send me a
PrintScreen of the comms debug window within BioExplorer.  From that raw
data it was very quick and easy to figure out what was going on.  It really
only took me a couple of minutes.  But I was lucky.  It could be more
difficult, depending on the complexity of the protocol, what sort of
hardware layer is used, etc., etc.  I implemented the QDS protocol on my
own EEG amplifiers, so in effect I did the inverse of what you should try
and do.

The other option would be to rewrite your current bio-amplifier's embedded
firmware.  That's what I would do - LOL.  It depends how good your amp is,
how expensive, what sort of micro it uses, etc., etc.  Basically you would
"teach" your amplifier a new language, for instance that QDS-protocol.
Then you could connect it to BE, Bioera and I would hope, to openVibe.  I
am pretty sure that Chris Veigl also has QDS support for BrainBay, due to
my publishing and implementing it on some of my hardware.

Good luck.

Regards
Stefan

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