From: Jim P. <ji...@ua...> - 2002-07-13 12:31:50
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David Horner wrote: > I have been trying to get a Bio-Feedback system together myself. I > am happy to hear there are other people working on a free and open > system! I am a software engineer and have just purchased a > expensive PCMCIA data aq. card from NI. I would like to help in the > efforts for the free Bio-Feedback software. > > I need to get my self a test system up and running. Right now I > just have the data aq. card. > (http://sine.ni.com/apps/we/nioc.vp?cid=4371&lang=US) I am looking > for a good place to aquire electrodes and whatever else I might > need. I am also looking for good books (can you suggest some)? Can > someone point me in the right direction? Is there an FAQ for this > group? I'm not the right person to answer most of these questions, but I thought someone should answer. At the moment, we are moving everyone off an old eGroups list to this new SF list, so not everyone is here yet to answer your questions. There are a few hardware guys who have been working on several designs for the circuitry, based on feeding the data in through the serial port. The big problem is isolation -- there should be no current path between your body and ground via the electrodes, otherwise touching an accidentally live case would cause discharge to ground through the worst possible path -- i.e. hand -> brain -> electrodes -> PC -> ground. They are using an optical coupling to achieve this. However, if you are doing things in your own way, using a PCMCIA card, and you are willing to take a risk, or run the laptop off batteries and make sure there are no other connections to anything grounded, you could perhaps use the signal amplifier stages of the circuits that they have been working on. One of the circuits (ModularEEG) is in the trial-production stage. Andreas is the one to talk to about this. On books, Jim Meissner suggested "The Awakened Mind" by Max Cade, but that appears to be unavailable, and I have not yet looked on the second hand sites for a copy. On software, so far we have had quite a bit of discussion, and Dave Fisher is working on a C++ framework, which he has working at a basic level with his ProComp hardware. I did some work on the signal analysis a while back, and ended up with BWView, designed to quickly get a visual understanding of brain-wave files. The analysis is much much better than the normal FFT approach, but takes more processing power, and is only really suited for analysis after the data has been recorded. http://uazu.net/bwview/ On electrodes, someone else will have to answer. It really depends on where you are based. In the UK people seemed to almost assume I was a terrorist or something, asking for electrodes without a medical background. I may have another go soon. In the US and Germany I think there are sites to get hold of them much more easily. I hope this will do until we get some more people over to this list. Jim -- Jim Peters (_)/=\~/_(_) ji...@ua... (_) /=\ ~/_ (_) Uazú (_) /=\ ~/_ (_) http:// B'ham, UK (_) ____ /=\ ____ ~/_ ____ (_) uazu.net |