Nurse call system

About R

R. is an alliterate child. When he needs something (such as changing position), he calls the nurses. He used to bang on his mattress to do this, but has lost his mobility and can no longer do so. Nowadays, he breathes more quickly to trigger an alarm on his respirator and call the nurses. This system is not adapted to the nurses, who don't always know whether R. needs something or has respiratory problems. The challenge is to find another system so that R. can call the nurses when he wants to.