Clear Airway Apnea = Central Apnea?

[timbalionguy]

In reading this all through, it seems to me that a reasonably accurate means of determining if an apnea ia obstructive or central could be had by combining all of the techniques discussed. FOT, TDR, ballistocardiography, sonar, as well as short, medium and long term breathing trends could all be used together. Digital signal processors are cheap and common enough to do quite an accurate job of spectral analysis on the pressure and flow signals. There is sufficient processing power in even midline CPUs to do the computational part. Sensors for pressure and flow are improving all the time, and their cost is coming down. Produced in volume, I bet you could make a machine that outperformed the current crop of ASV's at the price of a decent autoadjust machine.

I don't think a 100 percent identification of all events is necessary. Just enough to ensure that adequate therapy is provided in each case. Enough smarts could be put into the machines to modify their 'score' mid-event if need be.

[SleepingUgly]

On the PR System One, do the clear airway tests (puffs of air) occur in CPAP mode or only Auto-Pap?

[-SWS]

On the PR System One, do the clear airway tests (puffs of air) occur in CPAP mode or only Auto-Pap?

Well, according to this Respironics capability chart, that same clear-airway apnea event detection also occurs in the PR System One fixed pressure model (the RemStar Pro): http://advancedeventdetection.respironi ... ities.aspx

So if Respironics detects a clear airway in the CPAP-only version of the PR System One product line, you can safely bet they'll do the same on their APAP model running at fixed pressure. Respironics markets that advanced event detection with this important objective:

...the real advancement is its ability to point out when the patient is experiencing symptoms beyond classic OSA.

http://advancedeventdetection.respironics.com/ (and toward that objective you don't need a high sensitivity score to reveal useful albeit basic trends)

So the above event detection is not purely for the sake of running the APAP algorithm. A primary purpose is to notify the person reading that data if there are problems besides ordinary OSA. Case-in-point: the algorithm will do absolutely nothing in response to detected periodic breathing (PB). PR System One's PB event detection is purely for informational purposes---even on the APAP model.

So I presume the answer is yes, the airway puffs occur in CPAP mode as well---since Respironics does not relinquish that same capability on the CPAP-only model.

[-SWS]

In reading this all through, it seems to me that a reasonably accurate means of determining if an apnea ia obstructive or central could be had by combining all of the techniques discussed. FOT, TDR, ballistocardiography, sonar, as well as short, medium and long term breathing trends could all be used together. Digital signal processors are cheap and common enough to do quite an accurate job of spectral analysis on the pressure and flow signals. There is sufficient processing power in even midline CPUs to do the computational part. Sensors for pressure and flow are improving all the time, and their cost is coming down. Produced in volume, I bet you could make a machine that outperformed the current crop of ASV's at the price of a decent autoadjust machine.

I don't think a 100 percent identification of all events is necessary. Just enough to ensure that adequate therapy is provided in each case. Enough smarts could be put into the machines to modify their 'score' mid-event if need be.

Good points. Specifically, real time constraints have been an issue in the past: event detection and event response must be closely coupled in real time. The early-model Weinmann FOT machine previously discussed in this thread, for instance, did not process traditional flow signals. The current Weinmann FOT machines now process those flow signals in addition to FOT-based resistance calculations.

[Muse-Inc]

In reading this all through, it seems to me that a reasonably accurate means of determining if an apnea ia obstructive or central could be had by combining all of the techniques discussed. FOT, TDR, ballistocardiography, sonar, as well as short, medium and long term breathing trends could all be used together. Digital signal processors are cheap and common enough to do quite an accurate job of spectral analysis on the pressure and flow signals. There is sufficient processing power in even midline CPUs to do the computational part. Sensors for pressure and flow are improving all the time, and their cost is coming down. Produced in volume, I bet you could make a machine that outperformed the current crop of ASV's at the price of a decent autoadjust machine.

I don't think a 100 percent identification of all events is necessary. Just enough to ensure that adequate therapy is provided in each case. Enough smarts could be put into the machines to modify their 'score' mid-event if need be.

Good points. Specifically, real time constraints have been an issue in the past: event detection and event response must be closely coupled in real time. The early-model Weinmann FOT machine previously discussed in this thread, for instance, did not process traditional flow signals. The current Weinmann FOT machines now process those flow signals in addition to FOT-based resistance calculations.

Ya know, this makes me wonder if my emWave trainer and the equivalent PC version might add useful info re the heart rhythm. These are designed to help a person learn to entrain the other electrical generators in the body to the heart. Based on biofeedback from an ear or finger sensor, they show the heart rate variability and rhythm, pulse, entrainment %. I use it for relaxation as it does a great job of helping switch attention, focus, breathe rhythmically & slower (at least my portable one does), but now I wonder if the science behind that could be used to identify when electrical generators get out of sync as I'm sure they must during events. Not so idle musings from Muse, who needs to logoff and get her butt in bed to get up and go somewhere early tomorrow .

[rested gal]

The only time I ever PERSONALLY saw Muffy upset was when Volvo decided to put ballistocardiography inside their vehicles... without asking his or her opinion of upgrading all the seat belts to respiratory effort belts... <Vaudeville drum roll>
---
Did I mention there was automotive mayhem to pay after Volvo stuck to their guns with the ordinary seat belts...?

Of course, the tragic incident involving Cousin Claire was also very upsetting...
---
Cousin Jebidiah had a similar end, but he didn't seem to mind as much:

Crazy people .... ... I'm on a message board with CRAZY people!! And lovin' it.

[rested gal]

cotech50 posted on page 8 in a recent thread that has quite a mixture of "serious", "banter", and...ummm...more:
"Clear Airway Apnea = Central Apnea?"

I didn't see a question in his post there...
viewtopic.php?p=436476#p436476

I just ran a report and looked at my worst night ahi 4.1 but was seeing a trend where the CA numbere were going up from the summary. In looking at the graphs they clearly show the CA issues and some transitioning to higher pressure is occuring at the end of my sleep period. I sometime lie in bed for a s much as 45min b4 I get up and not sure if I am starting to drowse off again or what but this helped explain my higher numbers.

... so am not sure if that thread in general was what bothered him.

[Muffy]

Maybe Muffy was so upset he...

"She."

No wonder people are confused.

going start reading again ans see where that leads me.

I forgot the to put "apnea" in this post:

viewtopic.php?f=1&t=47953&p=437109&hilit=fot#p437109

so it made no sense. I also added some more explanation to try to clarify that point.

In http://chestjournal.chestpubs.org/conte ... 60.full#T3

Central apneas most often occurred at sleep onset or followed arousal with a big breath.

Venous return is aided immensely by "big breaths". There is often a consequent increase in stroke volume (as well as increase in heart rate) to manage this increased preload. I would submit that the COs seen in post-arousal centrals are due to/aided by this phenomenon.

Muffy

[Muffy]

cotech50 posted on page 8 in a recent thread that has quite a mixture of "serious", "banter", and...ummm...more:
"Clear Airway Apnea = Central Apnea?"

I didn't see a question in his post there...
viewtopic.php?p=436476#p436476

I just ran a report and looked at my worst night ahi 4.1 but was seeing a trend where the CA numbere were going up from the summary. In looking at the graphs they clearly show the CA issues and some transitioning to higher pressure is occuring at the end of my sleep period. I sometime lie in bed for a s much as 45min b4 I get up and not sure if I am starting to drowse off again or what but this helped explain my higher numbers.

... so am not sure if that thread in general was what bothered him.

I believe he took offense by getting "mooned" by the woodpecker:



Muffy

[Muffy]

Ya know, this makes me wonder if my emWave trainer and the equivalent PC version might add useful info re the heart rhythm. These are designed to help a person learn to entrain the other electrical generators in the body to the heart. Based on biofeedback from an ear or finger sensor, they show the heart rate variability and rhythm, pulse, entrainment %. I use it for relaxation as it does a great job of helping switch attention, focus, breathe rhythmically & slower (at least my portable one does), but now I wonder if the science behind that could be used to identify when electrical generators get out of sync as I'm sure they must during events.

Already been done:

http://www.freepatentsonline.com/20080119747.pdf

But I'll bet you won't find this software online:



Muffy

[dsm]

The only time I ever PERSONALLY saw Muffy upset was when Volvo decided to put ballistocardiography inside their vehicles... without asking his or her opinion of upgrading all the seat belts to respiratory effort belts... <Vaudeville drum roll>
---
Did I mention there was automotive mayhem to pay after Volvo stuck to their guns with the ordinary seat belts...?

Of course, the tragic incident involving Cousin Claire was also very upsetting...
---
Cousin Jebidiah had a similar end, but he didn't seem to mind as much:

Crazy people .... ... I'm on a message board with CRAZY people!! And lovin' it.

RestedGal,

Yes, that craziness appears to be quite entertaining to some - lets just hope it doesn't end in a meltdown

Cheers DSM

[-SWS]

Yes, that craziness appears to be quite entertaining to some - lets just hope it doesn't end in a meltdown

That warm smile makes me feel all fuzzy inside... And those anti-meltdown hopes---openly shared with obvious benevolence for all to see---somehow amazingly manage to sit there like a retaliatory "verbal bomb" just waiting to be detonated...

So is there an official word or term for that? ...You know, when someone drops a potentially inflammatory comment that is completely disguised in smileys and gestures of warm benevolence? Somehow that little "verbal bomb" nicely sitting up there, just waiting to go off, doesn't quite match the writing or advertising on the outside of that volatile little package. Eh, dsm? That said, I think I'm done with this thread. It's been nice.

Cheers.

[timbalionguy]

Ya know, this makes me wonder if my emWave trainer and the equivalent PC version might add useful info re the heart rhythm. These are designed to help a person learn to entrain the other electrical generators in the body to the heart. Based on biofeedback from an ear or finger sensor, they show the heart rate variability and rhythm, pulse, entrainment %. I use it for relaxation as it does a great job of helping switch attention, focus, breathe rhythmically & slower (at least my portable one does), but now I wonder if the science behind that could be used to identify when electrical generators get out of sync as I'm sure they must during events. Not so idle musings from Muse, who needs to logoff and get her butt in bed to get up and go somewhere early tomorrow .

Interesting. I know of an interesting example of such 'training', but it could be a lot of things besides electrical. A co-worker at the zoo had a very close bond with a lion she had raised (Yes, I have to drag lions into EVERYTHING!). She would take naps with him, at a spot in the caging where they could touch each other while they napped (lions LOVE touching their friends while sleeping!). When she would wake up, she would often find that they had synchronized their breathing with each other. Maybe the real fix to central apneas is to sleep with a lion. He/she will train you to breathe properly while sleeping!

Muffy, those spectral graphs have some interesting data on them. Will have to read the entire paper (and see the entire graphs), but they show a means of long-term 'training' a machine to recognize centrals. The 'real time adaption capability of xPAP machines will come with increased data like this, and more powerful computers in smaller packages.

-SWS, sorry to see you leave this thread. Every time you post, I learn.

[dsm]

Yes, that craziness appears to be quite entertaining to some - lets just hope it doesn't end in a meltdown

That warm smile makes me feel all fuzzy inside... And those anti-meltdown hopes---openly shared with obvious benevolence for all to see---somehow amazingly manage to sit there like a retaliatory "verbal bomb" just waiting to be detonated...

So is there an official word or term for that? ...You know, when someone drops a potentially inflammatory comment that is completely disguised in smileys and gestures of warm benevolence? Somehow that little "verbal bomb" nicely sitting up there, just waiting to go off, doesn't quite match the writing or advertising on the outside of that volatile little package. Eh, dsm? That said, I think I'm done with this thread. It's been nice.

Cheers.

Steve,

Nothing so esoteric (great imagination ).
When simply crazy behavior becomes bizarre, it can be seen as a possible prelude to an emotional meltdown & that to me is a genuine concern.

DSM

[-SWS]

Well, that was very kind of you to recognize our behavior as "simply crazy", "bizarre", and "a possible prelude to an emotional meltdown". And it was even kinder of you to so warmly warn the public.

Silly thing is, with my formal training in deviant social behavior I didn't even manage to spot all that. Here, let me give you some warm smileys for recognizing all that, and then performing that kind public service announcement:


All better! Thank you! We are lucky to have you here explaining these things to us...