(08-14-2016 04:45 PM)FFOGHORN Wrote: My original post was about perception - and I stand by it.
You decided to chime in with a series of responding posts which are filled with assumptions and that you have yet to support with fact. I don't feel it does anyone a service to suggest one knows more about Resmed algorithms than he/she can document. I'm well aware of what Trigger and Cycle do, however, under VAuto mode they are interacting with multiple other functions to maintain airway patency on-the-fly.
And incidentally, contrary to your emphatic statement above, Rise time is unrelated to Easy Breathe. I'm certain you will try to educate me on why I'm mistaken, but Easy Breathe isn't a function AVAILABLE under VAuto mode only S mode. Further, one enables or disables Easy Breathe in S mode, so a reader might infer from your statement that there would be no rise time if Easy Breathe were disabled? You did say: "Rise time in Vauto is controlled by Easy Breathe." And the Rise/Decay slope you keep referencing is actually Patient Flow; it doesn't directly represent a timing of Rise.
Lets take this in some sort of order. First, Easy Breathe is selectable in the S mode and is the default in the Vauto mode. To prove that this is a correct statement, set your Aircurve 10 to S mode and go into the the menu and ensure that Easy Breathe is turned off. Also make sure that your IPAP and EPAP are reasonable with a reasonable separation. Mask up, turn the machine on, and breathe with the machine for 5 minutes then turn Easy Breathe on and breathe with it for 5 more minutes. Look at the mask pressure in Sleepyhead for the little test you just ran. Expand the X axis so that there is about a 1/2”-3/4” EPAP pressure line between each IPAP pressure line. Compare the mask pressure graph for a normal night's sleep in Vauto mode with the two you just created. Which does it look like??
There is an easier way to do this but it depends on trust. Look at the mask pressure graph at the following link: http://i.imgur.com/GcI9IZd.png
. There is a section with Easy Breathe off and one with it on and they are marked. Compare against similarly expanded mask pressure chart from normal Vauto mode
What is done to increase the pressure in the VPAP system? Answer: The flow is increased at a constant resistance. The Patient flow graphs that you are talking about are time based and we have just covered the direct relation between flow and pressure. With an accurate and highly sensitive time based flow rate graph one can actually measure the rise time.
(08-14-2016 04:45 PM)FFOGHORN Wrote: I submit to you for the last time that the VAuto is a fairly sophisticated piece of equipment. When one scrutinizes Resmed's documentation, however, it becomes fairly obvious that Rise time, which cannot be set in VAuto mode, relies on various algorithms to function and must MUST BE ELASTIC. I cannot prove that - and you can't or won't prove otherwise.
If you look at your normal mask pressure graphs while in Vauto and expand the X axis so that reasonable distance between each peak you will see that the shape of the curve leading up to the peak is the same every time. It will stay that way day in and day out. This is because Easy Breathe is controlling it and it is not being controlled elastically. It is also not a straight line but a curve...thanks to easy breathe.
(08-14-2016 04:45 PM)FFOGHORN Wrote: One thing is for certain: if Resmed states that a prolonged Rise time inhibits pressurization and should not exceed Ti Max, then there is an implied correlation between Rise time, Ti Max and perception of comfort. And comfort is what everyone is seeking on this forum.
It appears that you have a mis-perception of what Ti max does. Ti max only kicks in if you have failed to switch from inspiration to expiration spontaneously before the Ti max time is reached. If you are still breathing in when the Ti max interval is reached, Ti max will switch the machine to EPAP pressure at the same speed as normal.
The rise time should not be long enough for the inspiration time to exceed Ti max because that will cause the machine to mess up its ability to synchronize with your breathing.
Also the link that you posted for your back-up goes to an area that has nothing to do with your supposed quotes.