Has anyone here built a heart beat logger? I'm wanting to log each beat,
not the average rate.

It would be worn by the user while sleeping. Wireless would be ideal,
but tethered is not out of the question.

I've looked at some of the exercise watches, but they seem to log
activity (average / min / max rate), which is not what I'm after.

Hospitals have them but I would think they're not in the "buy for
yourself" price range.

A medical one I've seen has 4 posts (~ 80mm x 120mm pattern) on the case
that you press against your bare chest. You can hear a tone (~ 2KHz ?)
modulated with each heart beat coming from an internal piezo. It records
for 60 seconds, then you upload to the hospital via a phone, just like
an old acoustically coupled modem! (except it's one way)

One thing I've seen is the chest straps with micro transmitters.
Normally a watch picks up the signal, but Polar do make an OEM receiver
module. The straps are easy to buy, but I've not found any where local
that sells the modules yet.
David...

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___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: www.audiovisualdevices.com.au
___________________________________________

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