Re: [buildcheapeeg] Re: I published current design at SourceForge

From: Jim Meissner (jpmeissner_at_mindspring.com)
Date: 2001-12-01 17:51:55


Dear Jim Peters and group:

Could someone guide me as to how to find the published design? I went to SourceForge and could not figure out how to get it? Jim Peters found the file but could not read it. I am not a software guru! I am good at low noise analog stuff though.

As I mentioned before, in 1996 I had a complete working EEG system. Since conversing with Doug, I am looking to find the pieces and put it together and get it running again. The bad new is that I moved since then and you know what that means.

I have found the majority of the hardware, and yesterday I found the software for both the HC11 and the Borland C++ program for the PC.

I also found many Mega bytes of REAL EEG data. The data is about several different people and one of them is a very gifted Medium from England (very interesting data). I would be happy to make that data available if someone(a computer guru) could tell me how to do it. I could put this data on mywebsite to be downloaded?

Switching away from HC11 to Amtel. The code to make the HC11 play is not complicated, (less that 1/2 page of code), but I had to hire a consultant toteach me how to. I hope that after 5 years I still remember how! Is there someone on this list who can program the Amtel in assembly language? Doyou have the software tools and debuggers? Can an old dog learn new tricks?

The discussion about fancy filtering should be shelved until you guys look at REAL data. In my opinion, any filter, especially a sharp (high Q) filter will create artifacts and completely mislead you. The Mind Mirror is a perfect example. That is designed with very sharp multiple pole filters theoutput of which is averaged before being sent to the LED display driver. Those of you who have read Anna Wise have seen those strange frequency spectrum displays. When you look at that data with a good FFT you get quite a different picture. What most people don't realize is the mind does not put out coherent steady state frequencies! I have created a test file where I amplitude modulate a tone with a sine wave and you will see the sidebandson the FFT. When I pulsed the frequency you will see three frequencies show up that look real. An eye blink (impulse) has a wide frequency spectrumand if that were run through a filter you would think there were real frequencies there.

If you want to build stuff, I can give you a schematic of what I have. What format should that be in? I could do a paper sketch and scan it. For professional work I use Orcad, but that has been a few years.

Juergen P. (Jim) Meissner
Check out my Website at www.MeissnerResearch.com
Read about the benefits of the Brain State Synchronizer sounds for improving your life and health.
----- Original Message -----
From: Jim Peters
To: buildcheapeeg_at_yahoogroups.com
Sent: Saturday, December 01, 2001 6:00 AM
Subject: Re: [buildcheapeeg] Re: I published current design at SourceForge

Answering a couple of posts in one go ...

Jim Meissner wrote:
> Mr. Nyquist was not violated. Doug combined two statements. I
> built a system that transmitted 3 bytes at 9600 Baud, that is two
> channels with a reference byte. With that configuration I was able
> to run at a 200 to 300 Hz rate. The other version transmits 5
> bytes, or 4 channels. On that version I set the sampling rate so
> that I see about 65 to 70 Hz. That avoids the 60 Hz causing
> aliases.

Oops -- I didn't connect Doug's comments with your previous posting.
Sorry about that.

sleeper75se_at_yahoo.se wrote:
> > This is where most of thee hard work lies. I am a
> > software guy. How can I get myself up and running with
> > the current design? Can it be breadboarded? Is there
> > any software for the PC side yet?
>
> If we design a simulator first, then we wouldn't need the hardware.
> Here's a proposal: A program that allows the user to draw (using the
> mouse) a frequency curve, then transforms it into a FIR-filter by
> using the inverse fourier transform. Apply white noise to the FIR-
> filter and we have a simulated EEG-signal.

Yes, that could be done, but where's the fun in that ? It doesn't
really get interesting until you have some real live data to play
with. Having never played with an EEG device, I'm not going to know
how I want to approach it until I see how the data behaves.

I've had a read through the PDF on the web-site now:

http://openeeg.sf.net/design_challenge/design_challenge.pdf

This is all excellent stuff. If there is a microcontroller compiler
available for this processor for Linux, I'll certainly be up for doing
some coding of modules to download. And, like my SBaGen tool,
(sbagen.sf.net), I'm very happy to use the GPL and open-source
everything.

I also downloaded the schematics from the project page:

http://sf.net/projects/openeeg/

But I obviously don't have the correct software to view these.

As soon as this design gets to the stage where I can build the thing
using a soldering iron and a simple multimeter (no fancy test gear),
I'd very much like to try it out.

Jim

-- 
Jim Peters (_)/=\~/_(_) Uazú
(_) /=\ ~/_ (_)
jim@ (_) /=\ ~/_ (_) www.
uazu.net (_) ____ /=\ ____ ~/_ ____ (_) uazu.net

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