Why doesn't APAP respond to apneas?

Snoredog- thanks. Agreed that the templates are there to display autoSV-unique PB, multiple IPAP traces (min, max, peak), etc. I was wondering if there was supposed to be a newer Encore release that supersedes this "ASV buggy" release. So far my guess is that we're looking at two separate issues:

1) typical buggy Encore Pro reporting software (eg. that average IPAP peak of 15 cm while running at 14 cm CPAP), and
2) a firmware bug related to ramp and CPAP setup and/or BPM and CPAP setup (Bev probably found an acceptable workaround---albeit not a fix per say)

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Ozij- I think that's a pretty good theory. My hunch is that if the machine relied on longitudinal patient breathing variables, the clinician's manual should mention procedures to clear those longitudinal values. The machine will also be deployed in clinical environments where multiple patients will be either sequentially treated or studied using the same autoSV machine.

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Bev, have you decided on your preferred game plan for tonight? Detour or continue baselining? You are the boss. My strong hunch is that we are looking at items one and two above.

I'm going on with the baseline. I feel pretty good today, without the headache.

Ozij, I think you got it right. The machine is smarter than we think. I'm sure that there is an easier way to clear data for the next patient. Just zeroing it out isn't that hard, if you know that you need to do it.

Bev

ozij wrote:I think someone mentioned something similar before:
The machine learns breathing patterns
It may remember those breathing patterns from night to night - and eventually, but not immediately - FIFO - forgets older nights.
Maby the operational verification is a way of clearing the learned memory
And maybe that learning behavior is why dsm's machine was wacko after his experiments.

O.

#2 NOTE correction to BPM rate*******

The machine does appear to have some intricate algorithms - one very strange thing mine did during experiments is shown on this video that I didn't show previously because it was nothing like I expected & I wasn't confident I had set it up right.

This was with BPM=4 INSP set to 1.2 & epap at 10 ipapMin at 12 & ipapMax at 30

While trying to simulate a no flow central - power on - pressure goes to approx 10 (shown at mask) then on ipap pressure went immediately to 28 CMs then back down then seemed to reduce ipapCurr by 2 CMs then it stays at around 22 CMs (the other video test I linked to behaved more predicatbly, it shows it starting low & increasing by 2 CMs.

http://www.internetage.ws/cpapdata/dsm- ... ipapsv.wmv (pls excuse the quality )

DSM

OutaSync wrote:Ozij, I think you got it right. The machine is smarter than we think. I'm sure that there is an easier way to clear data for the next patient. Just zeroing it out isn't that hard, if you know that you need to do it.

A new or erased smart card sure makes sense to me---regarding how to clear out long term data from one patient to the next.

Although taking advantage of longitudinal data makes very good sense to me, I haven't seen any hints of it in the patent descriptions or marketing literature. I think it's an excellent idea. And who knows, maybe that feature is in there...

dsm wrote: While trying to simulate a no flow central - pressure went immediately to 28 CMs then back down then seemed to reduce ipapCurr by 2 CMs then it stays at around 22 CMs (the other video test I linked to behaved more predicatbly, it shows it starting low & increasing by 2 CMs.

http://www.internetage.ws/cpapdata/dsm- ... ipapsv.wmv (pls excuse the quality )

DSM

I think this is that other link you referred to:
http://www.internetage.ws/cpapdata/dsm- ... papsv2.wmv

Those gradual 2 cm steps are called "Parameter variation for proportional assist ventilation":
http://www.google.com/patents?vid=USPAT6532956 (see Fig. 3)

It allows for gradual 2 cm step-ups when more IPAP pressure is needed from breath to breath. It also allows for gradual 2 cm step-downs when less IPAP pressure is needed. Either of those gradual 2 cm stepped IPAP procedures can be very quickly outranked by single-step IPAP pressure increases/decreases, should algorithmic detection priority warrant.

That's not to confuse the above 2 cm stepped IPAP approach with those quick 2 cm puffs that are used to very quickly calculate pressure/flow fixes relative to instantaneous airway resistance (not quite differentiating central from obstructive events, but close).

SWS: I could be wrong but there was a 1.9 version but my understanding the only difference in that one was it was for Europe.

Snoredog wrote:SWS: I could be wrong but there was a 1.9 version but my understanding the only difference in that one was it was for Europe.

It sure sounds to me like Bev deserves a European vacation then.... Besides, she already has a Navigon 5100 that works in Europe.

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The last time I went to Europe, I slept 17 straight hours when I got there. Jet lag and untreated apnea don't mix well. I don't want to go again until I can get my sleep straight.

Version 1.9 would be newer or older?

Bev

OutaSync wrote:The last time I went to Europe, I slept 17 straight hours when I got there. Jet lag and untreated apnea don't mix well. I don't want to go again until I can get my sleep straight.

I don't blame you one bit, Bev. You'll get there!

OutaSync wrote:Version 1.9 would be newer or older?

That would be newer. But Snoredog thinks the changes may be nothing more than additionally accommodating the European version of this machine. That sounds plausible.

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-SWS wrote:Those gradual 2 cm steps are called "Parameter variation for proportional assist ventilation":
http://www.google.com/patents?vid=USPAT6532956 (see Fig. 3)

It allows for gradual 2 cm step-ups when more IPAP pressure is needed from breath to breath. It also allows for gradual 2 cm step-downs when less IPAP pressure is needed. Either of those gradual 2 cm stepped IPAP procedures can be very quickly outranked by single-step IPAP pressure increases/decreases, should algorithmic detection priority warrant.

I probably should have pointed out that the patent description covers more parameter variations than were implemented in the autoSV. Specifically the D1, D2, and D3 implementations ended up in the autoSV as 2 cm increments. However, the EPAP levels 66, 68, and 70 did not receive parameter variation in the current autoSV design. The patent description still legally protects the currently employed D1, D2, and D3 part of that description---which really isn't a proprietary low-level design document anyway.

-SWS wrote:

Snoredog wrote:SWS: I could be wrong but there was a 1.9 version but my understanding the only difference in that one was it was for Europe.

It sure sounds to me like Bev deserves a European vacation then.... Besides, she already has a Navigon 5100 that works in Europe.

I have 3 or 4 Garmins, I got the Nuvi 360, has bluetooth speakerphone, built-in MP3 player, I used it once
to go to Mexico, I was driving at night, buddy had only given me vague directions, I knew I needed to head
down the toll road Hwy 1, its dark, no big deal, Sir Farts-a-lot was co-navigating in the front seat, no big
deal I got GPS,

As soon as I drove across the boarder into Mexico, the screen on the GPS goes blank. Yep it works alright,
knows exactly where you are and knows you didn't buy the maps for Mexico

I still made it there, buddy said when you see the do not litter sign at km mile marker 21=1/2 turn right, I did and there he was. 5 minutes later Sir-farts-a-lot was hiking his leg on his bushes and I was having a corona on the patio watching the waves crash in.

That reminds me, I still need to purchase the Mexico maps for the Nuvi, Mexico is apparently NOT part of North America.

Since you were nice enough to study up for my brain surgery (meaning three quick video reviews), I figured the least I could do was garner three quick Mexico map links:
http://www8.garmin.com/cartography/ontheRoad/
http://www.amazon.com/s/ref=nb_ss_gw?ur ... co&x=0&y=0
http://shop.ebay.com/items/_W0QQ_nkwZga ... R40QQ_mdoZ

Do you have any history of pulmonary disease? Do you smoke? Ever have a Pulmonary Function Test or an Arterial Blood Gas? Shortness of breath with even mild exertion? Do you have blood work that lists -HCO3 or Total CO2?

SAG

I'm certainly no medical pro or guru, but it sounds like SAG is wondering about the possibility of hypercapnia. One of the symptoms associated with hypercapnia is headaches.

Along that same line of thought Snoredog has been wondering about hypoventilation at night because of what just may be low apparent volumes. Sleep related hypoventilation is one possible cause of hypercapnia.

-SWS wrote:

dsm wrote: While trying to simulate a no flow central - pressure went immediately to 28 CMs then back down then seemed to reduce ipapCurr by 2 CMs then it stays at around 22 CMs (the other video test I linked to behaved more predicatbly, it shows it starting low & increasing by 2 CMs.

http://www.internetage.ws/cpapdata/dsm- ... ipapsv.wmv (pls excuse the quality )

DSM

I think this is that other link you referred to:
http://www.internetage.ws/cpapdata/dsm- ... papsv2.wmv

Those gradual 2 cm steps are called "Parameter variation for proportional assist ventilation":
http://www.google.com/patents?vid=USPAT6532956 (see Fig. 3)

It allows for gradual 2 cm step-ups when more IPAP pressure is needed from breath to breath. It also allows for gradual 2 cm step-downs when less IPAP pressure is needed. Either of those gradual 2 cm stepped IPAP procedures can be very quickly outranked by single-step IPAP pressure increases/decreases, should algorithmic detection priority warrant.

That's not to confuse the above 2 cm stepped IPAP approach with those quick 2 cm puffs that are used to very quickly calculate pressure/flow fixes relative to instantaneous airway resistance (not quite differentiating central from obstructive events, but close).

In looking at both the videos again, it seems the SV starts off (in what ever direction is applicable) doing 2 CM steps the after approx 3-4 at 2 CMs it seems to switch to 1 CM steps.

Also, I keep wondering what the machine does if it decides someones breathing rate is too high (say sleeper's av is 13 bpm & they drift above target perhaps to 16 bpm, I can see the machine using rate cycling to try to nudge the breather's rate down but I can't see that the machine would try to use pressure support (inceasing pressure) as well to achieve its goal of slowing the sleepers rate down. BUT on the other hand, I can see it (and my tests show it does) use cycling AND PS when trying to increase someone's bpm rate.

I agree that the short 'puffs' are a separate mechanism used for probing. They are very mild and not really disturbing - it seems to do them if volume is fluctuating along with rate. Any time I think I am aware of a hypopnea (i.e. just rolled over from side to side) I am aware of the PS repeating at increasing 2 CMs intervals. From the charts, it seems that any time an 'apnea' is detected it uses that same 2 CMs increases approach to bring av peak flow back inline.

Bev, am hoping you are able to get it configured in a way that you feel comfortable with and can grow its use on that comfort.

DSM

OutaSync wrote:I'm going on with the baseline. I feel pretty good today, without the headache.

Yay!!!

-SWS wrote:A new or erased smart card sure makes sense to me---regarding how to clear out long term data from one patient to the next.

It does to me too. So, which smartcard were you using in the machine, Bev? Did you set yourself up as new patient? Did you use a
smartcard the SV had? Insert your own from the Auto without erasing it?

On the other hand, on other machines, they don't got through the following "operational verification" rigamarole, resetting all parameters , between patients.

5. Set the parameters to the following:

• 0 EPAP=4crnH2O
  • IPAP Mm = 30 cm H20
  • IPAPMax=30cmH2O
  • Rate = Auto
  o RiseTime = 1
  • Ramp=O(Off)
  • Patient Disconnect = 0 (Off)
  • Apnea = 0 (Off)
  • Low Minute Ventilation = 0 (Off)

Exit to the Monitoring screen.
6. Press the (5 button to turn the airflow on and put the device in the Operate state.
7. Occlude the outlet of the device for 4 seconds, and then open the outlet for 4 seconds. Do this several times while observing the manometer reading and the device display.

There are so many "if" relationships between the EPAP IPAP Rate and Rise time parameters (see the setup instructions) that maybe all the parapmeters have to be set to something that clears all those intedependecies...

O.