From: sleeper75se_at_yahoo.se
Date: 2001-11-29 16:10:47
--- In buildcheapeeg_at_yahoogroups.com, "Moritz von Buttlar" <info_at_baltic-microsolutions.de> wrote:
>If you don't have IrDA already in your PC, chances are high that
>there's a jumper on your motherboard where you can directly attach
>a IrDA transceiver. There are several plans around how to upgrade
>your PC to IrDA if this jumper is available.
Yes, you are right. I went digging for the motherboard manual, and
apparently it does support IrDA!
>> Now, does communication with the EEG-device really need to be
>> bidirectional?
>I think it would be a nice feature to have. Also for later
>improvements and so on.
I suppose you can make a dirt cheap version, but without any upgrade
options, that will probably cost more in the long run if ones
requirements change.
>But then you have to due all kinds of things like glueing the LED
>to the fibre and so on which aren't perfect or professional :)
Hehe, well, but its FUN! :-)
>I'm thinking about IrDA because it might save us from conducting
>some difficult safety tests needed for medical devices otherwise.
>(In germany you'd have to test the whole system - eeg,
>computer,software to comply to some complicated norms).
It's possible to save on that part but theoretically you can injure
somone badly by hooking up a pair of low-impedance electrodes and
connecting a 9V battery directly to them. We'll have to make sure
that even if the head-stage amplifiers get shorted to ground and
power, the user is safe. I think the maximum allowed limit is 0.1mA
current through the human body. Above that, things get uncomfortable
fast. 1mA can be sensed and 5mA is painful.
>Also it's convenient and modern and interesting.
Yes, it is. Are you thinking about a battery operated device here? I
think I read in a data sheet that the LED in a IrDA transceiver can
consume 100mA on average, and that is quite a lot.
/Andreas
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:32 BST