From: e_e_ling_at_h...
Date: 2001-04-01 23:25:51
Moritz
Thanks for your detailed reply, I am now using your information for
the news page.
Does IrDA mean the eeg can only be used with a notebook pc? If that
is the case, I think it would really restrict public interest in the
system as most people have desktop PCs. The brainmaster works on a
desktop so for most desktop owners it would be cheaper to buy a
brainmaster for their existing pc ($1000) than to buy our system and a
new notebook ($2000?). Did I understand you correctly or can IrDA be
used with desktops?
I agree that we need to fulfil some kind of safety criteria, but maybe
it doesn't have to be done immediately. As long as the eeg is safe,
i.e. won't blow up/electrocute us, it should be ok for us each to own
a test version for a few weeks; then we can make further improvements
to the design and research safety standards before releasing it to the
public... what do people think?
As for the manufacturers of expensive EEG and the pharmaceutical
companies... of course they won't like our cheapeeg! So yes, we have
to be careful, but we have to remember one thing: an EEG provides
information. It measures brainwaves. That's it. It has no effect on
the user at all, unless that user actively engages in biofeedback
training. I don't believe biofeedback can have any harmful
consequences but in any case it is the user's choice, so I really
don't think we should be worried about this.
What are "mignon NiMH" batteries? I did a web search and all the
matching sites were in Germany - is it a german battery? Will this be
a problem for the rest of us?
Finally, you mentioned you were in discussion with an electrode
supplier. What kind of electrodes are you thinking of using? Is it
possible to use flextrodes (from Brainmaster) which require no gel?
Regards
Eric
> There are also people who might not like our
> cheapeeg. (The manufacturers of expensive EEG maybe or the pharam
industry as
> well)
--- In buildcheapeeg_at_yahoogroups.com, Moritz v. Buttlar <info_at_baltic-microsolutions.de> wrote:
>
> Hi !
>
> Iīm sending you now the current status of the hardware (the part Iīm
working on)
> Joerg will probably do the same.
>
> Iīm trying now to implement IrDA. Itīs quite difficult and Iīm not
sure yet if
> it will work and whether itīs a good idea in the first place.
> The alternative would be to use very good optocouplers and connect
the EEG by
> cable to the computer. This is a safety issue. If we use IrDA nobody
can make
> serious mistakes by connecting something wrongly. Many small
notebook computers
> are equipped with IrDA connectors, but many desktop PCīs arenīt.
> We have to find out what the people want :)
> And also what kind of safety norm we have to fulfill if the eeg
should ever be
> manufactured and sold. We really should try to find somebody who has
knowledge
> about all the legal issues we face with our project.
>
> What do we have to write on the website in order to make sure that
we donīt
> get into trouble if somebody gets hurt when trying to build the
cheapeeg from
> our plans ? Or if somebody claims that he got schizophrenia by using
our device
> ?
> I donīt think itīll ever happen but there are quite ignorant people
> on this planet....
> There are also people who might not like our
> cheapeeg. (The manufacturers of expensive EEG maybe or the pharam
industry as
> well)
>
> Iīm also trying to add a very good AD converter featuring 20bit /
25kHz
> (ADS1250). This allows a better dynamic range. The ADC also includes
a digitally
> programmable amplifier stage. Therefore we can control the
amplification by
> software (no more manual adjustment necessary). It costs only 6$ and
is one of
> the best ADC available. I know that 20bit arenīt really necessary.
But the
> additional bits can be used for amplification as well (just shift
the result to
> the left and you get an amplification by 2). Our design probably
wonīt be good
> enough to get 20bit resolution, but maybe 18bit-16bit.
>
> Further changes to the current design:
>
> - battery supply (4 mignon NiMH batteries), no more DC/DC converter
that brings
> noise and is expensive and has only 1000V isolation. This will allow
about 8hrs
> continual operation.
>
> - New microcontroller: Ubicom (former Scenix) 50Mips
microcontroller. Costs the
> same as the Atmel and IrDA stack is available for download from
Ubicom. Thatīs
> why Iīm quite sure the IrDA part will work sometime :). Itīs 5 times
faster than
> the Atmel microcontroller.
>
> Right now Iīm working on a CNC (computer numerical control) machine
which can
> automaticly manufacture printed circuit boards. Itīs controlled by
my PC.
> Therefore Iīll be able to design the board on my PC and then
manufacture it
> automatically.
>
> Software: IMHO all the software designed for the EEG should be
> Gnu-public-licensed. Only if we have a complete open software source
code,
> people will start writing their own improvements for the software.
> It would be good if we had something like the Gnu-license for the
hardware part
> as well.
>
> The prototype by Joerg thatīs already working features:
>
> - RS232 connection using opto-isolation
> - 2 channels / 10 bit (using the ĩC-internal ADC)
> - works with PC-Software by Rob Sacks
> - Power supply with DC/DC converter
> - it works :) !!!
>
> The new philosophy is:
>
> We want to separate the analog and digital part. This will allow
enhancement of
> the analog/digital parts separately without the need to redesign
the whole
> system.
>
> Joerg developed the state machine for EEG/PC communication. This
protocol
> should also be published on the website. It allows programmers to
communicate
> with our device.
>
> If you want me to, I can buy the website. You can send me some bucks
by post
> if you want to chip in. Regarding the name: letīs start a new vote.
Is it
> possible to allow 2 votes for everybody ?
>
> Maybe Joerg can send some photographs of his design. Maybe we could
include
> a to-do list on the website to recruit people ? And a list of the
people
> already involoved with email-addresses and a description of what
they are doing
> ?
>
> Write me if you want more information about the hardware design.
>
> Moritz
>
>
> --
>
----------------------------------------------------------------------
---- > Baltic Microsolutions / Flash Microcontroller Custom-Development > http://www.baltic-microsolutions.de
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