Macpage wrote:palerider wrote:pressure *VARIES* as you breath in and out due to different amounts of FLOW, and the RESISTANCE of the various parts of the circuit (humidifier, hose, and, yes, mask) affect the flow, and thus, the pressure.
Would this be why there can be a "perceived" flow difference by the user with different masks of the same type at the same pressures?
it's hard to say, perception is a fickle thing, and when you're talking subtle things, it's anybodies guess whether it's an actual or imagined difference. sometimes actual differences are missed and other times there are differences felt that don't exist... witness the many reports of wine 'experts' declaring one wine better than another,
decisively, when it's actually the same wine in both bottles...
or an experiment I performed with some fig bars that came in "three flavors" fig, raspberry, and blueberry... I couldn't tell any difference in the taste, but my housemates said they could... so I set up a test, and fed them bits of different flavors... and marked down what they thought.... they were surprised, sometimes saying the same bar was definitely different flavors, or saying getting the flavors wrong,... it was conclusive, they all taste like fig, and there's not enough other flavor to matter. they're still tasty though.
Macpage wrote:
I certainly thought that I could tell the difference between two nasal masks. Thus, would Phillips be trying to make an adjustment that while not critical might smooth out any perceived difference between any of their masks and more accurately deliver the prescribed pressure at the "fine lines" (allowing for the marketing play).
well, I don't think that it has anything to do with perception, I think it, and the resmed mask selections is just taking advantage of increased computing power to model the flow dynamics of the breathing circuit in order to get more accurately delivered pressures at your face.
the old resmed ASV machines had a sensing tube that ran back from the mask to the machine so that the machine could read the pressure at the mask and compensate. with the hugely greater computing power available today, they can calculate the effects of the humidifier, hose diameter and length, and yes, the mask openings, make adjustments of the pressure at the machine to better deliver the desired pressure at your face. (at least, that's my theory until I hear something better )
Macpage wrote:
I notice that Resmed says select pillows for the Nano nasal mask. I have assumed this would apply to the Wisp and Eson nasal masks as well as they have similar specs. What exactly would we look for to make sure of the proper selection
the resistance specs in the back of the manual. I sat down and looked up resistance of a bunch of resmed masks, made a little spreadsheet, and sorted it by resistance.... and with just a couple of exceptions, the masks fell neatly into the pillow/nasal/full face lineup, even though their vent rates varied more.