Inspirometers also require that the breath be taken in as slowly as possible. This device: https://lamusainstrumentos.es/en/smile-plus.html https://lamusainstr

Inspirometers also require that the breath be taken in as slowly as possible. This device: https://lamusainstrumentos.es/en/smile-plus.html https://lamusainstrumentos.es/en/smile-plus.html Has a little yellow flowmeter on the left side that has to stay within a particular range. On this version, it is a smiley face, but on other models there are three ranges, the slowest intake being the best.