[Novalug] OT? : sleep apnea devices

shawn wilson ag4ve.us@gmail.com
Sun Aug 28 12:06:04 EDT 2011

On Aug 27, 2011 5:10 PM, "Beartooth" <beartooth@beartooth.info> wrote:
> On Sat, 27 Aug 2011, Fredrik Nyman wrote:
> > Pulse oximetry (SpO2) is an extremely common medical application for
> > microcontrollers, so you should be able to find reference designs from
> > most any of the big MCU vendors.  TI definitely has it.
> >
> > And no, a pulse oximeter doesn't necessarily need an OS.  You could
> > implement it as a simple data logger recording to flash or
> > transmitting the data wirelessly or just do some math on the measured
> > data and displaying the results on a LCD.
>        I can believe that; but how about the CPAP and APAP
> machines I linked to??

Short answer - no.

All of this can be done with microchips. Look at atmel for a hobbiest chip
and NXP, TI, microchip, etc as well. I think you're more interested in RE
than chip development though. So, chances are you'll be able to find the
chip sold and download specs for it. Past that, chances are, there's a bit
that has been flipped or other way of preventing you from looking at the

At this point you can either look at the signals going to the chip and
program your own processor. I don't think you want to go down this path at

Have you looked at the files / data on the sdcard? Have you opened anything
up in a hex editor? Is there a 'format card' option on the machine? If so,
give it simple one and five minute tests and see what changes. I would doubt
they went through the trouble of encrypting this stuff - obfuscation with
crc should ensure 'good enough' ip security and data integrity.

So, how much time do you have?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.firemountain.net/mailman/private/novalug/attachments/20110828/7c818a6d/attachment.html>

More information about the Novalug mailing list