From: Jim Peters (jim_at_uazu.net)
Date: 2002-03-02 21:04:10
Jim Meissner wrote:
> Please compare your bwview display with the FFT waterfall and let me
> know "what you think" and which provides better data. This is not
> meant as a "mine is better than yours" discussion. At this point in
> the development of your bwview program, I believe the FFT waterfall
> works better. I hope you will incorporate it into your program as
> an option.
I have something working already. It is a 'sideways waterfall' at the
moment, but it gives similar benefits. I'm not sure whether you will
like it, but we will see. I plan to allow reorientation of the
display so that it is the conventional way around:
This is in fact just the colour 'voice print' display sliced up and
given some height. You can also look at it from the left (meaning the
peaks go left instead of right), letting you see into any areas hidden
by tall peaks.
Once I have it going up/down it will probably make more visual sense,
though.
> I really like the idea of the voice print display, and after you add
> color it will show a lot more.
> I would also like to see the FFT waterfall display with a log
> frequency scale that you suggested a while ago.
Yes, fine.
> The oscilloscope display is very important. Without looking at the
> brain wave display you cannot know what the FFT or voice print
> frequencies mean. A clipped waveform will produce a large number of
> "false" frequencies. It is also important to see the right and left
> hemisphere coherence.
Yes, this is the next thing for me to do. I have to re-jig everything
so that I can display multiple channels simultaneously.
> If you look at the Downey file, you will see a series of low
> frequency pulses that look like eye blinks but are not. These have
> a Delta frequency component, but are half sine pulses that might be
> REM or sync pulses. Very interesting? I wish that I had 12 or 16
> bit resolution while making this recording.
At this stage, with no practical experience, I have no idea how to
tell apart blinks and electrode movement and all the other stuff that
could get into the recording. You mean the bit between (roughly) 100
and 170 seconds on chan 1/2 ? (That is shown in the GIF above?)
Jim
-- Jim Peters (_)/=\~/_(_) jim_at_uazu.net (_) /=\ ~/_ (_) Uazú (_) /=\ ~/_ (_) http:// B'ham, UK (_) ____ /=\ ____ ~/_ ____ (_) uazu.net
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