.....someone here is sure to know the answer.

I had a brief incarceration very recently (not at Her Majesty's
Pleasure !) in the local hospital to have knee keyhole surgery. This
is why this is not DIY!. I got round to having a bath this morning
and one of those sticky sensors they slap on just before they knock
you out, came off my back.

Anybody know what these are for as I seem to remember a number being
stuck on me. Electrical connection is just one way via a pop
connector - and actually I now realise when I went to say the
connector is like an antistatic strap, that these must measure
resistance for some reason. the sensor looks like a thin metal plate
with some film on it.

Who's the medical guru round here ?

Rob