Has anyone got any experience of these things?
When family members have been stuck in hospital they have been hooked up to professional monitors for pulse rate and oxygen concentration. When we go to see the GP the first thing they use is a little clip on meter that goes on the end of a finger.
A quick search on the internet brings up lots of choice with prices starting at £20.
When we have been worried we have gone and got help - that will not change - but there have been occasions when we haven't been worried but probably should have been. If these little monitors actually work reasonably accurately it might be worth having one next to the inhalers