oh i meant to reply to the other one...b ut didn't! lol
ds was monitored overnight a while ago (he was about 3 months then)
we went in in the evening and we had to get him asleep before they fixed up all the equipment.
basically he had this thing taped on his top lip which was just like a thin, flexible bit of plastic with little metal probes which went in each nostril (not very far) and one which went down to his mouth.
that measured how much he was breathing in and out.
he also had a thing taped onto his toe to measure his oxygen levels.
it was ok except for when he woke in the night for a feed and managed to yank the thing off his face and i couldn't get it stuck back on properly!!!
from the equipment they had though we could see that they could also video him, and they can measure the chest movement and stuff as well... but didn't do any of that with him!