I just had a loooong discussion with jedimark about this very subject, so it's fresh in my mind it resulted in the new estimated excess leak trace for respironics in the beta sleepyhead.Jay Aitchsee wrote:Thanks PR, apparently I read my sources wrong. I thought the Amara vent rate was about 10 L/min greater than the N10, but from your references, I see that's not the case. And I agree, most masks are pretty close.
previously, he was calculating the excess leaks for respironics by doing the same kind of math that the resmeds do, looking at flow, watching the inspiration,expiration and calculating a baseline flow... only there was no sanity check... it worked fine for most people, but now and then you'd have someone who *never* got a good mask seal, so the baseline would be skewed. this would, in a few cases, result in someone having flagged large leaks and a really good looking 'excess leak' line.
the machines themselves have access to more data than they record, so they can compensate for this.
in the latest beta, he's gone with a flat 20-50lpm vent rate (at 4-20cm pressure) default which can be adjusted by the user if desired. it's all a bit of an approximation anyway, because all the mask specs say "depending on manufacturing tolerances" and such...
