On Wed, 14 Jan 2009 17:56:23 -0500, axolotl
wrote:

Don Foreman wrote:
The
key spec is probably 60Hz B field at 1 gauss (0.1 millitesla).
Finally, something I can get some traction with.

What I would worry about is the fast rise time stuff from the arc
getting into the defib sense wires and having the induced noise
interpreted by the processor as the erratic spikes of a heart in
trouble. A 60 Hz sine wave is probably tolerable.

I used to use a lot of this stuff when I was chasing EMI fields:

http://www.chomerics.com//products/documents/emicat/pg190shieldwrap.pdf


If you want to try it in your test setup, send your address and I will
send out a couple of feet.

Thanks, Kevin!

The leads they now implant are shielded and differential/bipolar, and
I strongly doubt that they are inclined to experiment on live
patients.

The devices employ both low-level analog filtering and digital signal
processing. A V-tach heartrate of 300 bpm is still only 5 Hz.