measure respiration rate

Other Hardware Science and Measurement
1

What's the smartest and simplest way to measure respiration rate? Preferably, non invasively.

It's for an art project, where a person sits in a spot. Their breath will control lights and sounds. I want the lights and sounds to match the breath.

I can control exactly where they sit. I can also control in what position they sit. I can make them wear stuff. But for best effect it should be something where they just need to sit. Then a functionary doesn't need to be present.

Will an IR camera work? Or doesn't the breath change the body temperature enough?

I've also thought about a stretchy band around the chest, and then measure tension/stress. But I don't know which sensor that is.

Please help? Any ideas would be valuable. Not sure which route to go

2

how you want to measure it, by detecting pressure or temperature? there are ways by using temp sensor, using pressure gauge, u can also use microphone.

3

EJLED:
how you want to measure it, by detecting pressure or temperature? there are ways by using temp sensor, using pressure gauge, u can also use microphone.

Any method that works is good. As long as it gets the job done, I have no opinion on method.

There might be background noise. So I think a microphone might not be reliable.