Marc,
Thanks for getting back to me.
There's another product here :
**broken link removed**
I'm not sure it has any accelerometers though.
It does have to be wireless and send back live data regarding a person's heart rate and movement. I need the data as it happens so there is no requirement to log and download.
Initially I just wanted one unit so I could sit there and write some software \ experiment with what I want to do.
If, as you suggest however, this would be a difficult and costly exercise, then I shall just leave it as a pipe dream....! I think the link to 'DIY' project in my initial post fooled me into thinking how simple this might be.
Someone on another forum suggested I write to to Alive Tech and ask If I could use their product and write my software. But a) I can't get hold of them b) I cant find where to buy the product in Europe.
If the Zephyr had movement detectors I would the ask them the same.
thanks for your advice.