From: Rob Sacks (editor_at_realization.org)
Date: 2000-10-10 17:47:31
Hi Yaniv,
Hmm, I took a look at that, but I'm not sure
it helps. He says it's for filters that aren't
bandpass, lowpass, etc., but my filters need
to be just plain bandpass filters.
Also, if I understand him (maybe I don't), he's
describing a long FIR filter. I'd rather use IIR
filters because they have a lot fewer taps for
the same accuracy, so they run a lot faster.
The way Tom did it looks good, but I can't
find anything that describes how to implement
it. (I understand the general idea of making
quadrature-phase and in-phase streams, but I don't
know how to select the sine/cosine frequency or
how to recombine the reference signals with the
filtered signals after they come out of the lowpass
filter.)
The other way that looks possible is to make
individual IIR filters on the fly for each desired
frequency band. The trouble with that is, I don't
know how to calculate the phase of the result,
and I need phase.
Rob
----- Original Message -----
From: "yaniv vilnai" <yaniv_vi_at_yahoo.com>
To: <buildcheapeeg_at_egroups.com>
Sent: Tuesday, October 10, 2000 6:45 AM
Subject: Re: [buildcheapeeg] hi .
> hi rob
> about the filters , i remembered in somethin :
> here's one of the best education about dsp
> http://www.dspguide.com/pdfbook.htm
> look at chapter 17 , i think there's youre solution .
> but another thing
> if you get a impulse response of a filter
> with a lot of very small values in the start
> (near zero etc ) , that would be long delay , so
> consider taking them out to get fatser response .
>
> but i think the best way is what tom did in b.m.
>
> bye
> --- Rob Sacks <editor_at_realization.org> wrote:
> > Hi Yaniv,
> >
> > Thanks for telling me about the Brainwaves list.
> > I just joined it, but my German is pretty rusty, so
> > I didn't understand much.
> >
> > > rob will you agree to put your software for free ,
> >
> > > that he may use with his machine ?
> >
> > I think probably, yes, but first I want to know more
> > about their project.
> >
> > > doing serious research on the value of eeg to
> > meditation , writing an
> > > article on the proven
> > > qualities of eeg as meditation help aid ,
> > > and with this knowldge raising the awareness of
> > the meditation
> > > community .
> >
> > I think this is a good idea, and I've begun to do
> > this
> > on my website. For example, I (re)published this
> > article
> > at the beginning of the summer:
> >
> > http://www.realization.org/page/doc0/doc0073.htm
> >
> > Rob
> >
> >
> > ----- Original Message -----
> > From: <yaniv_vi_at_yahoo.com>
> > To: <buildcheapeeg_at_egroups.com>
> > Sent: Monday, October 09, 2000 5:28 PM
> > Subject: [buildcheapeeg] hi .
> >
> >
> > > hi group .
> > > 1. eeg hadrware status -
> > > i found a german guy in the brainwaves group at
> > egroups
> > > that made a design of low cost eeg 2 channel
> > machine .
> > > he put the design on the site there - for
> > anybody to use.
> > > he thinks to sell it at about $177 per machine
> > .
> > > he's currently in beta testing of the device .
> > > for start i'm trying to communicate with him ,
> > and see if he needs
> > > help , and if he wants to cooperate with us .
> > > rob will you agree to put your software for
> > free , that he may use
> > > with his machine ?
> > > i don't know what's the guy's hardware status .
> > >
> > > 2. another subject that could help making a low
> > cost
> > > eeg is :
> > > doing serious research on the value of eeg to
> > meditation , writing an
> > > article on the proven
> > > qualities of eeg as meditation help aid ,
> > > and with this knowldge raising the awareness of
> > the meditation
> > > community .
> > >
> > > would anybody like to do this reasearch / or know
> > somebody who like
> > > to do it ?
> > > i don't think it's such a big deal to do the
> > article because alot of
> > > the stuff is found in books like "megabrain"
> > "awakend mind - anna
> > > wise" and after you got premission you make an
> > article and start to
> > > putting it inside popular meditation sites .and
> > maybe other things of
> > > public relations ?
> > >
> > >
> > >
> > > sincerly yaniv v.
> > >
> > >
> > >
> > > To unsubscribe from this group, send an email to:
> > > buildcheapeeg-unsubscribe_at_egroups.com
> > >
> > >
> > >
> >
> >
>
>
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