From: Rob Sacks (editor_at_realization.org)
Date: 2000-10-21 05:22:30
Hi Tom,
What a pleasure to get this message from you! It filled
me with encouragement and motivation to know that
somebody with so much experience and knowledge
is involved.
I'll just quickly answer the software questions
that relate to me personally. Then gotta go to bed and
get up early, driving to Synchronicity Foundation
tomorrow for eight days to play with high-tech
kundalini.
My committment to the project is to write the PC
program. This will be a commercial-quality
application written in Visual C++.
Actually, it's partly written already. The current
version does a brain mirror and phase coherence
based on FFT. It does not yet have digital filters for
fast threshholding, an interface for inputting protocols,
or any kind of sound or light production. In other
words, at the moment it's a profiling tool, not a
feedback tool.
If nobody else volunteers, I might be willing to write
microprocessor code, but I kinda hope somebody else
volunteers. :)
> As I work with consultants all the time, it is important
> for anyone contributing to a project like this to have
> comfort with the level of integrity of the participants...
I'm not sure exactly what you're thinking of, but this
comment reminds me to make sure everybody knows
that I am simultanenously involved in a separate, second
EEG project.
This other project is (at the moment) a hardware/software
development effort. The particpants plan to raise money
and start a company to market this device. The reason I
have software partly written to donate to the CheapEEG
project, is that I'm using the same code to test some ideas
for the other commercial project. At some point it may
turn out that I have to separate this code into two codebases,
one of which would be public domain for the CheapEEG,
and the other would be proprietary and sold by the startup
company.
I want to make sure everybody is comfortable with this
because I can imagine the following scenario taking place,
and it might seem sleazy. The scenario would be that I
donate free code to the CheapEEG; it will be a pretty good
program; but at the same time, a more powerful version of
the program would be on sale by an unrelated, for-profit
company. So in effect, the CheapEEG project woudl be sort
of marketing a for-profit product sold by a separate company.
On the other hand, wht might make it less sleazy would be
if I put the CheapEEG version entirely in the public domain
so anybody can make a derivative work from it. But I would
want to clear this with my partners in the other project.
If I drop out of this thread for the next week or so, it's only
because I left for Virginia before seeing replies. I don't
expect to have email there.
Regards,
Rob
----- Original Message -----
From: "Thomas Carr" <tomcarr_at_e...>
To: <buildcheapeeg_at_egroups.com>
Sent: Friday, October 20, 2000 12:22 PM
Subject: [buildcheapeeg] current issues
> Hi Yaniv, Joerg, Rob and everyone,
>
> I'm just emailing some basic questions I have at this stage, as I told
> Yaniv, I don't really have time this year to do R&D but am still interested
> in the project. As I have said, I have a manufacturing facility in Los
> Angeles which makes industrial computers and can do this if it is desired.
> My true interest is in the creation of a reasonable EEG, I think the time
> has come, and will be happy just to see the product available to all,
> regardless of my involvement in the creation. However, design and
> manufacture of a product like this is something I have experience at, so
> issues are easy for me to see. At this time, I see these issues that raise
> questions for me:
>
> 1. Investment by Joerg and Rob
> I commend the efforts and time dedication of Joerg and Rob and look forward
> to this project having postive results for all concerned. As I work with
> consultants all the time, it is important for anyone contributing to a
> project like this to have comfort with the level of integrity of the
> participants, so I would suggest that these issues are important for anyone
> doing work, it's an investment of your time, so be specific on these issues
> (ie, value your work), don't wait and expect everything will work out to
> your satisfaction. Increased communication is the key on this issue.
>
> 2. Amplifiers
> The amplifiers Joerg is designing don't appear to have any expensive
> components, I have accounts with most major electronics distributor and so
> can usually obtain parts at a significant savings to radio shack or even the
> broad based players like digikey. The parts on the amplifiers will probably
> be matched by the pcb 'real-estate' cost, and the assembly another equal
> part. I would guesstimate this at about $10+ per amplifier. I think that
> Joerg is correct in careful consideration of these amplifiers. Biosystems
> amplifier concepts are much more sophisticated than Brainmaster and I can
> say that I've worked with sensor interfaces to micro-processors for about a
> decade, and this is where systems always fail or perform poorly. It would
> be wise to understand that this part of the platform will require the most
> testing and fine tuning. If we succeed in a big way here, we will have an
> excellent product. But tweaking this can take a lot if time.
>
> 3. A/d
> Is there a current plan regarding the a/d? biosemi uses a 16 bit, I'm not
> sure that an 8 bit won't due, has anyone looked into this? as we are
> measuring brainwaves from 1-40hz, it would seem that 8 bit would easily give
> us .2 hz resolution, which should be adequate, is my thinking correct? A 16
> bit bus may increase costs.
>
> 4. channels
> as well, how many input channels are we thinking of? brainmaster has 2
> channel, but if we create the amplifiers in a modular format, we could have
> up to 8 channels pretty easily, I don't know the performance value of this,
> but it would seem that more than 2 channels would increase value and
> application and a basic system could then be increased easily by adding more
> amplifier modules. Typically, then, within the chassis we might put 2
> amplifiers on the motherboard and then have headers for adding amplifier
> modules.
>
> 5.opto-isolation
> In the biosemi system, they multiplex the A/D through fiber optics and then
> use a pc card to interface the data, this is of course a very expensive way
> to go (not in general but within the $ parameters of this project). A key
> here is the opto-isolation. Bio-system is using fiber optics, when I asked
> Tom Collura, he suggested a "comercial opto-isolator", does anyone have any
> imput on this? The idea, as I've dealt with this before but in other
> circumstances, is that we have a small potential on the amplifier side for
> safety and use the opto-isolators to isolate from the pc side.
>
> 6.comm method
> It appears you are focused more towards rs232 and 485, rather than a pc card
> like the biosystem uses, in which case we can use the parrallel port on a pc
> to accept signal data. The maxims 232 (or233) chips are pretty standard, we
> can reduce to 3 wire interface if we take it down to 485 using a 75176. If
> we use the right micro-processor, we don't have to add a uart, there are
> uarts on board, so this saves $, too.
>
> 7. 3 parts to software
> Does Joerg have a micro-processor in mind and is he writing that software.
> Or is Rob writing the PC software and the micro-processor software? Then,
> there is the comm software itself, the micro-processor is usually
> self-sufficient and the PC is also, the comm process is the link.
> Which software is Rob using for the PC? I know comm functions on visual
> Basic are pretty straightforward, but you typically have to drop the data
> into a database that your user interface then accesses. Visual C++ is
> certainly infinitely more capable, but much more complex to write as well
> unless you already have some adaptable software. This is absolutely where
> the most time investment will take place, and I mean A LOT of time.
>
> 8. the pcb
> Does Joerg have CAD capability for schematic capture and PCB layout, though
> I don't have too much time, this is a very important aspect to a product's
> longterm reliability and robustness, as well as maintaining cost
> considerations. As stated before, while I don't have the time to do the R&D
> this year, I can probably do the board layout work for the project when it
> gets to that stage if no one else has capabilities and experience (and after
> doing several motherboards, I can say experience is key, probably why Tom
> Collura used a pre-made board). So, in this way, I can take the product
> from prototype to successful manufacture. I interject now as this is a very
> important step, good to have a tentative plan in advance.
>
> 9. major components cost estimate
> we have to have these components which are pricey: micro-processor($5),
> ram($3), rom ($3), 232 ($4), power supply transformer ($8), opto-isolation
> (?), a/d($5), pcb ($15), box ($7), LED's and switches ($5), assembly/tech
> ($30), misc parts ($5-10). If we go with a mpu that has ram and rom
> onboard, we may have to get a uart ($5) so the tradeoffs have to be
> considered. With 2 amplifiers, the cost is up to about $100. Typically in
> manufacturing, you'd figure at least a 2:1 ratio for other costs compared to
> COGS, so we're looking at about $300, this all depends on volume, which
> won't be large as we are starting from scratch with no resources. So, while
> this is much cheaper than $1000 for the 2 channel brainmaster, it's not
> $100. Basically, if you remember, Yaniv, this was what I suggested the sale
> price would be at the start of this project. I welcome correction in my
> estimate. What is the other $200 for? basically overhead, marketing,
> distribution and income for those who are investing their valued time- at
> this point, these are all theoretical. If you go through distribution, they
> mark up, which is figured as a discount off the list price (list price is
> $300, they get 40% off = $180 to the wholesaler). Typically, the
> manufacturer makes more than the wholesaler, so this would raise the sale
> price to $400. Welcome to the world of manufacturing :) As I said, good to
> look at this ahead of time, I value everyone and feel they deserve to be
> compensated accordingly. And it's good to take a look at these issues before
> they become issues :)
>
> even a prototype run of 25 will cost $3-4000 as you have to purchase parts
> in quantity and there are engineering start up charges, where is this budget
> coming from, which says nothing about promotional costs which will be just
> as much just to get started. underestimating it won't change the bottom
> line.
>
> best regards, tom carr
> tomcarr_at_p...
> www.piercingtheveil.com
>
>
>
>
>
>
> To unsubscribe from this group, send an email to:
> buildcheapeeg-unsubscribe_at_egroups.com
>
>
>
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:27 BST