[Goronmon]

...as a parent, that anxiety was already there for me, and I think it's there for most other parents too. I used to wake up and check my daughter in the middle of the night because she hadn't cried in a while. This would have brought me peace of mind.

This echoes my own experience in this area.

[AstralStorm]

And what would you do should this device mislead you? Sue the company making the nonmedical device?

Might as well just attach a sensor directly to the kid instead. Something tiny, like wireless EMG electrode or MEMS accelerometer. Much less likely to get a false positive. (The problem is batteries, as usual.) Heck, a pulseoximeter.