ASV SleepyHead Data definition question

[palerider]

and mask type. ...plus (maybe) mask type.

I don't believe there's a mask type setting on the prs1...

there's certainly no mask type setting in sleepyhead (that's used)

I know you REALLY want the mask type to be critical to leak calculations...

[archangle]

and mask type. ...plus (maybe) mask type.

I don't believe there's a mask type setting on the prs1...

There's a mask resistance setting, that might be used to infer something about mask type.

I didn't remember whether Encore had a field for mask type, but I guess it doesn't.

I know you REALLY want the mask type to be critical to leak calculations...

I don't really care that much.

It's one of the inputs that could be used if the machine or software had that information available.

I suspect the actual PRS1 calculation is some variation of "find the minimum leak seen at that pressure and assume that's the intentional leak" or "use this intentional leak vs. pressure curve for all masks."

I seem to recall my S9 AutoSet does use the mask type in its intentional leak calculation, but am not sufficiently motivated to look that up right now.

[palerider]

I seem to recall my S9 AutoSet does use the mask type in its intentional leak calculation, but am not sufficiently motivated to look that up right now.

you keep saying that, but the evidence says otherwise (eg, wildly different leak rates for various pillows that are all under the 'nasal pillow' setting.)

the thread you linked earlier had jedimark relaying information that a respironics person told him " I asked her how Encore calculates unintentional leaks.. She said it's calculated using set values for each pressure, regardless of mask type.."

[archangle]

I seem to recall my S9 AutoSet does use the mask type in its intentional leak calculation, but am not sufficiently motivated to look that up right now.

you keep saying that, but the evidence says otherwise (eg, wildly different leak rates for various pillows that are all under the 'nasal pillow' setting.)

Well, luckily, convincing you isn't really that high on my list of priorities.

[palerider]

Well, luckily, convincing you isn't really that high on my list of priorities.

I have to admire how you never let facts get in the way of your opinions

[bwexler]

You must realize by now we each have our oppinions, and they are vastly supperior to facts.

Even Columbus ignored the FACT that the earth was FLAT as everyone but him knew.

[Pugsy]

Regarding Encore and unintentional leaks.....it has to pull it's computations from the machine...the machine supplies what it needs to figure it out. Encore can't make up figures without something to base the figures on. Think about it. Encore doesn't use the magic eight ball to pull a leak number out of its butt.

Again....a Respironics software tech told me that the machine pulls a leak baseline of sorts from when the machine is started up and we would assume excess leaks are minimal and uses that to have a starting point.

Mask Resistance has nothing at all to do with leak calculations. Mask Resistance is the amount of Resistance that each mask has in its inherent structure.

Palerider...I will try to find some suitable comparisons for Encore leak .....both intentional and unintentional leak reports and how they compare with SleepyHead reports. May take me a bit as I am going to have to dig into some old reports unless I have good examples with my camping trip to the mountains last month when I used my PR S1.

Edit.....PR do you think maybe we need to do a new thread with my examples so as to not hijack this thread anymore than we have and maybe some of the leak explanations might help newbies???
I have some images but not all ...almost ready to upload to Photobucket.

[palerider]

Edit.....PR do you think maybe we need to do a new thread with my examples so as to not hijack this thread anymore than we have and maybe some of the leak explanations might help newbies???
I have some images but not all ...almost ready to upload to Photobucket.

yeah... it's more of an unrelated research project

[archangle]

Again....a Respironics software tech told me that the machine pulls a leak baseline of sorts from when the machine is started up and we would assume excess leaks are minimal and uses that to have a starting point.

Are you sure the tech was talking about an intentional leak detection function? The machine has to keep a running calculation of total leak at all times in order to make the flow rate waveform be centered around zero. Could the tech have been talking about how they start this calculation up? Long term, this is a running average of the hose flow rate, but you need to figure out how to set the initial value when you start the machine up.

If they do calculate an intentional leak, why is there no unintentional or intentional leak data recorded on the SD card? Apparently, Jedimark couldn't find it. Check this thread: viewtopic.php?f=1&t=73250

Maybe it calculates some sort of intentional leak rate and uses it in some of its internal calculations like apnea detection, and central detection.

Regarding Encore and unintentional leaks.....it has to pull it's computations from the machine...the machine supplies what it needs to figure it out. Encore can't make up figures without something to base the figures on. Think about it. Encore doesn't use the magic eight ball to pull a leak number out of its butt.

Once again, the only sensors the CPAP machine has is a flow rate sensor and a pressure sensor. (There's also a humidity sensor, but I doubt that figures in here.) All the data the CPAP or Encore has is calculated comes from analyzing those two sensor readings. Some of the calculations are done inside the CPAP machine, some are done in Encore.

In this thread, viewtopic.php?f=1&t=73250, Jedimark says he talked to a PR representative who told him that Encore calculates intentional leaks from the pressure, not that it gets the data from the CPAP machine.

"I asked her how Encore calculates unintentional leaks.. She said it's calculated using set values for each pressure, regardless of mask type.. (Yay.. No voodoo magic involved!)"

Note it's Encore calculating unintentional leaks, not the CPAP machine.

I believe it works this way. The PRS1 machine calculates total leaks and records it. Encore calculates an intentional leak based on the pressure, and subtracts that from the total leak to get unintentional leak. Encore gets no information about unintentional or intentional leak rates from the machine.

In the thread linked above, it sounds like SleepyHead calculates unintentional leak by finding the minimum leak at each pressure. (actually a 10th percentile.) I don't know if he still does it that way. I know he's been tinkering with the PRS1 unintentional leak calculation for a while.

[Pugsy]

Are you sure the tech was talking about an intentional leak detection function? [/quote]

Yes....