From: Joerg Hansmann (jhansmann_at_g...)
Date: 2000-11-28 19:41:24
Hi yaniv,
----- Original Message -----
From: <yaniv_vi_at_yahoo.com>
To: <buildcheapeeg_at_egroups.com>
Sent: Tuesday, November 28, 2000 10:52 AM
Subject: [buildcheapeeg] hi folks
> great job people ,
> you ar awesome !!!
:-) thanks.
> got a machine working and
> first software version in such a short time - it's cool .
>
> about lawyers and stuff - i think you could find a person on the
> net via allexperts.com or similar site that would give us some
> advice .
>
> but my opnion is :
> 1. if we build the device safetly (e.g. infrared interface
Recently I have seen a schematic for RS232<->irda conversion.
The problem is that you will not get irda by simply connecting
a (modulated) IR-Transmitter to TxD and an IR-receiver to RxD,
because irda has shorter pulse lengths compared to RS232 at the
same baud rate. What is needed, is an IC that performs stretching
and compression of the pulses. Doing this in pure software on the
AT90S4433 could be possible but very tricky and could not make
use of the built in UART-hardware.
> ) and
> with right box ( plastik with metal foil) we'll be safe enough
The FDA probably wont think so before they have approved the device.
> 2. i think an assembled kit manufacturer have much experience in
> allot of this issues , and it'll maybe also be wise at this
> to start a connecting with such , to get some feedback ,
> and some connection .
> i think somewhere in the list there's a name of such a person .
>
> 3. about the patents : jeorg - you don't have the schematics of
> the brainmaster so how could you have stolen something from it ?
A patent would also be viloated, if I invented the same item protected by
the patent by pure chance.
BTW: Meanwhile I have found the schematics of the brainmaster on the net.
The overall priciple is identical to the RS232EEG (Instrumentation amplifier,
2nd amplifier stage, AD-conversion with microcontroller, bidirectional
opto-isolated RS232, AGND-generation, Feedback software on PC), but in
detail there are differences (e.g. way of DC-suppression, processor type,
communication protocol and speed, power-supply , etc.)
> if you suspect some part of you design wil be specificly liable
> to patent suit - please tell me .
The overall principle is the same.
> 4. i know that in circuit cellar they have sold a kit of eeg for $300
> but not an assembled on so you still need electronics knowldge .
> our point is getting a complete device - so maybe we can
> sell the electronic assemlbed board diffrently and the enclosure
> diffently - so it would be a kit .
The lawyer in the brainwaves-egroup has told me months ago, that
even an assembled pcb without casing would be critical.
> and we could take off any liability .
> and let's just keep to points again with this idea :
> very simple assembly & very very safe design !
>
...
> and jeorg for info about noise in eeg machines - loook at
> www.futurehealth.com there they also have some sp[ecs of some
> machgines in the market .
> and the noise in the b.m. is nasicly the noise in the input amp ad620E
> so check it .
...
I have done some noise measurements on the RS232EEG with Rob's
program and got about 1uVpp noise (RTI) with the old design.
That is better or equal to the BM.
If the new design works, it will have even less noise.
Regards,
Joerg
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