From: Michal Wallace (sabren_at_manifestation.com)
Date: 2002-07-07 05:50:36
Hey all,
Sorry for disappearing. I spent a couple weeks reading up on
electronics and how to interpret schematics and whatnot, and
kind of decided building the modularEEG was just way more
than I wanted to take on...
On the software side, I'm still very happy with the way
python is working out, so if someone wants to move my cvs
repository over to sourceforge, let me know and I'll zip it
up. Basically, I've proved to myself that I can build a nice
display if I had the hardware, but until I can get some
physical hardware to work with, there's not much point in
going further.
But that's not the point of this message... :)
When I first found this group, I read through the entire
yahoo groups archive and took notes (mostly links to
interesting posts)... I was going to organize them a little
better, but I just don't have time right now, so I figured
I'd post it here in case someone wanted to put it on the
website or just get a refresher course in some of the
interesting threads that have come up over the years.
Cheers,
- Michal http://www.sabren.net/ sabren_at_manifestation.com
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* tasklist
http://groups.yahoo.com/group/buildcheapeeg/message/702?expand=1
jiva's hardware tasklist:
http://groups.yahoo.com/group/buildcheapeeg/message/724?expand=1
* thermal feedback
http://groups.yahoo.com/group/buildcheapeeg/message/1003?expand=1
more detail:
http://groups.yahoo.com/group/buildcheapeeg/message/1005?expand=1
temperature feedback circuit:
http://groups.yahoo.com/group/buildcheapeeg/message/2717?expand=1
* incorporating (as nonprofit)
jim peterson:
http://groups.yahoo.com/group/buildcheapeeg/message/745?expand=1
* glossary
** uart:
Universal Asynchronous Receiver Transmitter
This chip was one of the first really successful integrated
circuits. In your PC, the UART is the key component of the serial
communications port. Data is tranferred within the computer in units
of 1 to 8 bytes, with a separate wire for each bit within the
byte. The UART receives a byte and converts it to a sequence of
voltage changes to represent the 0s and 1s on a single wire. The modem
takes the signal on this wire and converts it into sound. At the other
end, a modem converts the sound back to voltages, and another UART
converts the stream of 0s and 1s back into bytes of data.
-- http://www.cnet.com/Resources/Info/Glossary/Terms/uart.html
** PCB
printed circuit board
** optocouplers
Well, an opto-coupler is an electronics device or IC that couples two
sides of the electrical world by a light beam.
It is generally a one way traffic unless you use two of them to make a
two way traffic. This way they avoid all chances of data or signal
accident, and even can de-couple high voltages from shocking
experiences.
-- http://www.eio.com/public/eoptics/0075.html
* Cheap Electrodes:
the machine needs numChannels +2 electrodes:
http://groups.yahoo.com/group/buildcheapeeg/message/741?expand=1
rob kall sez most people use one channel:
http://groups.yahoo.com/group/buildcheapeeg/message/783?expand=1
rob kall sells 4 for $50:
http://groups.yahoo.com/group/buildcheapeeg/message/704?expand=1
ear clips ($30 or so):
http://groups.yahoo.com/group/buildcheapeeg/message/703?expand=1
some catalogs:
http://groups.yahoo.com/group/buildcheapeeg/message/695?expand=1
---msg 116 on build cheep eeg yahoo groups
As my grandfather bought a PCE-Trainer (standalone biofeedback-device,measuring ultra slow (brain) potentials)with a
set of headband electrodes included,which I was told on request was also used for EEG-measurements, it showed up that these are very simple made: the set consists of a 5cm rubber band which can be adjusted to fit any headsize.There are four 4 polished steel (nirosta) electrodes attached which are made of simple PRYM Snap-Buttons.On the
outside the unshielded electrode cables which are bundled into a (bajonett-locked) 5 pin Din-Plug,can be clipped in. The set costs about 100 $ and can be easily rebuilt for about 5$. The electrode placement (for the purpose of ULP-measurement) is as follows 2 (GND)dorsal,distance about 10 cm at height of eyes, 2 ventral,same distance,at temple-height. I guess for the EEG-Amplifier the AGND electrodes would be attached to the ears (with clips). Contact to the skin is established by applying saltless electrode-gel.
dry electrodes: (Super-Input) http://groups.yahoo.com/group/buildcheapeeg/message/1501?expand=1
john morrison's pincushion electrode idea: http://groups.yahoo.com/group/buildcheapeeg/message/2035?expand=1 and: http://groups.yahoo.com/group/buildcheapeeg/message/2088?expand=1 jim meissner responds: http://groups.yahoo.com/group/buildcheapeeg/message/2090?expand=1
jim m explains his headband: http://groups.yahoo.com/group/buildcheapeeg/message/2229?expand=1
* irDA adapter supposed to be "Easy": http://groups.yahoo.com/group/buildcheapeeg/message/493?expand=1
* electrode images http://groups.yahoo.com/group/buildcheapeeg/message/305?expand=1
"better" version, according to rob sacks: http://east3.com/technology_sensors.html
* using a sound card to cut costs http://groups.yahoo.com/group/buildcheapeeg/message/346?expand=1
a sound card schematic (for another project): http://groups.yahoo.com/group/buildcheapeeg/message/365?expand=1
how to read the sound card: http://groups.yahoo.com/group/buildcheapeeg/message/460?expand=1
Here's an article about using soundcards for data acquisition:
http://www.tmworld.com/articles/2000/03_sound.htm
problems with sound card: (joerg agrees several messages later): http://groups.yahoo.com/group/buildcheapeeg/message/545?expand=1
jim peters later talks about pitch shifting: http://groups.yahoo.com/group/buildcheapeeg/message/1617?expand=1 oh, but he meant not through a sound card: http://groups.yahoo.com/group/buildcheapeeg/message/1623?expand=1
fil laborde shows up and also says sound cards make it easier. (he also picks up on the need to frequency-shift): http://groups.yahoo.com/group/buildcheapeeg/message/1882?expand=1 jim m ressponds: http://groups.yahoo.com/group/buildcheapeeg/message/1884?expand=1 jim p clarifies: http://groups.yahoo.com/group/buildcheapeeg/message/1886?expand=1 but fil doesn't listen: http://groups.yahoo.com/group/buildcheapeeg/message/1892?expand=1 jim m points out the software required: http://groups.yahoo.com/group/buildcheapeeg/message/1921?expand=1
* software spec - including telepathy note http://groups.yahoo.com/group/buildcheapeeg/message/369?expand=1
what if you could hook these things up over the net?
* legal help (pro bono)
http://groups.yahoo.com/group/buildcheapeeg/message/151?expand=1
* software he sez it sucks: http://groups.yahoo.com/group/buildcheapeeg/message/436?expand=1
much later, he says how it works: http://groups.yahoo.com/group/buildcheapeeg/message/1868?expand=1
john morrison's diagram of how it should work: http://groups.yahoo.com/group/buildcheapeeg/message/1873?expand=1
* circuit board printer
Right now I´m working on a CNC (computer numerical control) machine which can automaticly manufacture printed circuit boards. It´s controlled by my PC. Therefore I´ll be able to design the board on my PC and then manufacture it automatically.
http://groups.yahoo.com/group/buildcheapeeg/message/216?expand=1
* working systems brainmaster has online plans for free? (should cost $200)
doug says biosemi is simple, and about $60 + electrodes: http://groups.yahoo.com/group/buildcheapeeg/message/1536?expand=1
* book the high performance mind by anna wise (uses mindmaster displays)
* map of the skull
If you're not familiar with the international 10-20 EEG reference system "O" stands for Occipital lobe. All odd numbers are on the left, all even numbers are on the right, so to locate O1 you find your inion, which is the bump at the very back of your skull, near the bottom where your neck joins your head. Then from the inion you move up about 3 cm and then to the left 3 cm so you are now maybe 4 cm due "northwest" of the inion. That is O1. If you were to find the symmetrically matching point on the right side of the head, that would be O2. The point directly between them is Oz. Everything on the centerline is designated with a "z", so Cz is the point at the very top of the head, Pz (parietal-z) is halfway back from there to the inion. Fz (frontal-z) is halfway from Cz to the nasion (the bump above your nose and getween your eyebrows), etc. You have to learn all that stuff for your BCIA EEG certification, and then you forget everything except the particular sites you use a lot on clients.
http://groups.yahoo.com/group/buildcheapeeg/message/292?expand=1
* development methodology / project management rob sacks: http://groups.yahoo.com/group/buildcheapeeg/message/514?expand=1
he mentions unit testing.. this would be easy with a sound card based architecture.
later, rob talks about lead developer/architect's role: http://groups.yahoo.com/group/buildcheapeeg/message/1071?expand=1
john morrison posts a project plan: http://groups.yahoo.com/group/buildcheapeeg/message/2234?expand=1
* questions ** what is a "channel"?
* games/control systems pac man: http://groups.yahoo.com/group/buildcheapeeg/message/1159?expand=1
skyflyer points out some games: http://www.altered-states.co.nz/mind/minddriv.htm
Joerg on response times: In my EEG-feedback sessions I have the impression, that changes can occur in fractions of a second. http://groups.yahoo.com/group/buildcheapeeg/message/1171?expand=1
virtual keeboard? http://groups.yahoo.com/group/buildcheapeeg/message/1294?expand=1
this company lets you control all kinds of stuff: (mindOS) http://groups.yahoo.com/group/buildcheapeeg/message/1365?expand=1
biofeedback sdk: http://groups.yahoo.com/group/buildcheapeeg/message/1210?expand=1
all sorts of links: http://groups.yahoo.com/group/buildcheapeeg/message/2706?expand=1
* interesting events / ideas: jim peters (sbagen) shows up: http://groups.yahoo.com/group/buildcheapeeg/message/1194?expand=1
joerg starts using it: http://groups.yahoo.com/group/buildcheapeeg/message/1177?expand=1
vladimir k gets schocked: http://groups.yahoo.com/group/buildcheapeeg/message/1213?expand=1
openeegbusiness list: http://groups.yahoo.com/group/buildcheapeeg/message/1220?expand=1
doug southerland posts a zillion links: http://groups.yahoo.com/group/buildcheapeeg/message/1264?expand=1
doug on EEG-enhacned google: http://groups.yahoo.com/group/buildcheapeeg/message/1481?expand=1 http://groups.yahoo.com/group/buildcheapeeg/message/1484?expand=1
doug places an order for the parts: http://groups.yahoo.com/group/buildcheapeeg/message/1510?expand=1 moritz points out how to make a parts list from eagle: http://groups.yahoo.com/group/buildcheapeeg/message/1515?expand=1
andreas suggests finding a kit manufacturer: http://groups.yahoo.com/group/buildcheapeeg/message/1580?expand=1
Andreas creates TinyEEG: http://groups.yahoo.com/group/buildcheapeeg/message/1678?expand=1
joerg's first results with sdl: http://groups.yahoo.com/group/buildcheapeeg/message/1722?expand=1
* manufacturing pcb's doug sez this: but he really wants a breadboard. http://groups.yahoo.com/group/buildcheapeeg/message/1290?expand=1
laurie points out the build-it-yourselfer angle: http://groups.yahoo.com/group/buildcheapeeg/message/1322?expand=1
how to gang up and buy 20 pcb's: http://groups.yahoo.com/group/buildcheapeeg/message/1442?expand=1
doug's cost analysis for rs232eeg: http://groups.yahoo.com/group/buildcheapeeg/message/1444?expand=1
but andreas points out you can put both circuits on one board: http://groups.yahoo.com/group/buildcheapeeg/message/1447?expand=1
more EEG pricing stuff: http://groups.yahoo.com/group/buildcheapeeg/message/1453?expand=1
joerg corrects the price on modularEEG: http://groups.yahoo.com/group/buildcheapeeg/message/1458?expand=1
reyelent will manufacture the whole prototype: http://groups.yahoo.com/group/buildcheapeeg/message/1460?expand=1
andreas says using "surface mount parts" can cut the costs: http://groups.yahoo.com/group/buildcheapeeg/message/1496?expand=1 ..but moritz says SMD's are scary for beginners: http://groups.yahoo.com/group/buildcheapeeg/message/1500?expand=1
* doug southerland on the different designs: http://groups.yahoo.com/group/buildcheapeeg/message/1325?expand=1
* building one simply:
jim p asks for what I want: http://groups.yahoo.com/group/buildcheapeeg/message/1969?expand=1
andreas posts the old brainmaster input stage: http://groups.yahoo.com/group/buildcheapeeg/message/1972?expand=1
another guy points out the standalone eeg, and how to make half of it: http://groups.yahoo.com/group/buildcheapeeg/message/1980?expand=1
jim p restates the case for building it: http://groups.yahoo.com/group/buildcheapeeg/message/1982?expand=1
Jim Meissener points out his own site with old radio shack parts: http://groups.yahoo.com/group/buildcheapeeg/message/1984?expand=1
jan 31: jim p finally builds it (no signal though): http://groups.yahoo.com/group/buildcheapeeg/message/2045?expand=1
tinyEEG.. as of may 20, it seems to be the final release: http://groups.yahoo.com/group/buildcheapeeg/message/2778?expand=1
he's now working on CheapEEG: http://groups.yahoo.com/group/buildcheapeeg/message/2780?expand=1
* new agey stuff jim p on his astral self and quantum physics: http://groups.yahoo.com/group/buildcheapeeg/message/2238?expand=1 jim m responds with his notes on mr downey: http://groups.yahoo.com/group/buildcheapeeg/message/2240?expand=1
* software dave points out the cross platform commonc++ stuff: http://groups.yahoo.com/group/buildcheapeeg/message/2244?expand=1 http://sourceforge.net/projects/cplusplus
dave seems to be working on something: http://groups.yahoo.com/group/buildcheapeeg/message/2768?expand=1
* python prototype:
audiogram for windows: [sdl real time sound program] http://kermit.fesb.hr/~kreso/
snack for messing around with sound files: http://www.speech.kth.se/snack/
pylab for FFT's, including FFTW wrapper: http://pylab.sourceforge.net/
serial ports: http://pyserial.sourceforge.net/ also: http://balder.prohosting.com/ibarona/en/python/uspp/uspp_en.html
http://www.meissnerresearch.com/Upload/download.htm
keeping the comport and software in sync: http://groups.yahoo.com/group/EEGS/message/74?expand=1
jim peters talks about binaurals: http://groups.yahoo.com/group/EEGS/message/92?expand=1 http://groups.yahoo.com/group/EEGS/message/94?expand=1
python signal processing with numpy!!! : http://www.onlamp.com/pub/a/python/2001/01/31/numerically.html
my code: http://cvs.sabren.com/sixthdev/cvsweb.cgi/openeeg/
* ffts fft intro (from numerical recipes book) http://www.ulib.org/webRoot/Books/Numerical_Recipes/bookcpdf/c12-0.pdf http://www.ulib.org/webRoot/Books/Numerical_Recipes/bookcpdf/c12-1.pdf http://www.ulib.org/webRoot/Books/Numerical_Recipes/bookcpdf/c12-2.pdf (etc.. just keep incrementing the last number)
a nice example that explains the concept of sound: http://www.intersrv.com/~dcross/fft.html#section1
neat interactive fourier transformation applet: http://sepwww.stanford.edu/oldsep/hale/FftLab.html
seems like a nice overview: http://astronomy.swin.edu.au/~pbourke/analysis/dft/
here's code that does an audio spectrum using FFT: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/osalp/src/aflib/aflibAudioSpectrum.cc?rev=1.10&content-type=text/vnd.viewcvs-markup
a frequency analyzer with source code: http://www.relisoft.com/freeware/freq.html
charlie has an oscilliscope and spectrogram: (no source code though) http://www.mississippi.net/~charlie/Downloads/Downloads.html
part of a winamp LCD plugin: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/lcdplugin/source/spec_anaylser/
a simple VB spectrum analysis program: (very easy to understand!) http://www.fullspectrum.com/deeth/programming/vb.html#Spect the author says in readme that you need ftp://ftp.microsoft.com/Softlib/MSLFILES/VBRUN60.EXE but it still required OCX files after that.
rob sacks says he uses about 1 second's worth of data: http://groups.yahoo.com/group/EEGS/message/31?expand=1
fast gabor transformation might be better: http://groups.yahoo.com/group/EEGS/message/50?expand=1 or not: http://groups.yahoo.com/group/EEGS/message/61?expand=1
* audiostrobe goggles I think that protocol is quite simple. When you want to LED goggle turn on you generate 19200 Hz tone to headphone. And goggles are detecting this signal.
http://groups.yahoo.com/group/EEGS/message/37?expand=1
* finding old books: advance book exchange
Oh wait -- before I get to the scientific papers, there is C. Maxwell Cade, the psychologist who invented the Mind Mirror, the NFB machine which is now emulated by practically every NFB program in existence. His book "The Awakened Mind" goes into detail about states of enlightenment (he numbers them from 5 to 8) and about the corresponding EEGs. Cade's book is out of print but you can easily find a copy on the website of Advanced Book Exchange (I buy a lot of used books, I've found that exchange to be best because it seems to be the biggest and the vendors don't seem to pass along a higher fee to you for using it).
C. Maxwell Cade has a sort of protege, Anna Wise, who wrote a book called "The High Performance Mind."
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:44 BST