cpvyb / openrespirator Goto Github PK

Hi,

Looking at slide 3 on the flow meter description file I noticed the smallest orifice in the airway is 2.5mm diameter (the one indicated as "2.5mm orifice with chamfered edge..") .

This is way too small at an inhalation/exhalation rate of 0.5l/sec (and it can be higher at high BPM) it creates a 62cm pressure drop (6250 Pa).
Beware patient's pressure ranges between 0cm-15cm peep and up to 40cm pip (peak inhalation pressure) levels.

It not only alters pressure readings but also impedes respiration itself. Try to breathe through a 2.5mm pipe.

In order to not alter breathing measurements by sensors themselves, they should create significantly less than ~1cm (100 Pa) pressure difference with their presence.