Quote: (Originally Posted by
AD_ward9)
In EN14143:2003 it states clearly in Section 6.3.2 that WOB and respiratory pressure has to be measured against the displaced volume, i.e. the piston in the breathing machine. That is one point is in the mouthpiece and the other the end of the piston volume inside the breathing machine. This correlates completely with the EN14143 calibration Lissajou, which gives 25mbar positive pressure under those circumstances, when the dimensions of the breathing machine match a human (dead volume, internal resistance etc).
Alex, that sounds weard to me..
I have been interpreting that WOB and respiratory pressure has to be 'plotted' against displaced volume, and not measured: exactly the graph from wich we can mesure the WOB
as far as I have seen a breathing machine like the ANSTI does in no means mach a human body in dead volume.. already the connection hoses from the piston to the mouthpiece, length minimum 3/4 meter, diameter 50/60mm
I have always interpreted the calibration orifice beiing used just to check volume displacement against pressurediff..
am I completely wrong, or do we express ourself wrongly??
paul