do research , page-46

True the spirometer requires marginal effort in blowing/exhailing but is far supirior in what data/information you receive from doing so.

Its a bit like you get out what you put in. If you want more accurate and detailed information which im sure all Asthma sufferes want you would go a spirometer as why settle for second best information when for a little effort you can get much better information that just may save your life.

I highly doubt the little effort needed to blow into a spirometer will negativily effect it and give ISN an adge as the information gathered through blowing into a spirmoeter is far greather then that of the wheezometer.