How Come? Auto Bipap seems to be fighting me.

So the doctor says go to 4/16....I went into the system and changed it down
to 4/16......lots of other info in there.

AbPAP
5.0
16.0
8.0
2
0:20
4.0 ramp start
0:00 start what is THIS?
0 Patient
1 Light
5 nights
AbPAP -------This completes the "circuit"

So, anyone understands the numbers...these are my settings
5.0 and 16.0 are my new IPAP settings...correct?
8.0 is my EPAP??

I was told the ....exhale setting was a "3" when I first got it. Is it really
an 8? I did NOT change the 8.0. The only change I made was the 25
down to 16.

Opinions?
Thanks........

dllfo wrote:5.0 and 16.0 are my new IPAP settings...correct? 8.0 is my EPAP??

5.0 is your minimum EPAP
16 is your maximum IPAP
8.0 is max PS (I think PS stands for pressure separation.)

You exhalation pressure will never be less than 5.0 cm. Your inhalation pressure will never be more than 16.0 cm. Conceivably your pressure differential could be 8.0 cm (i.e., 8/16, which seems like a lot, but I expect the BiPAP-auto will normally keep the differential to something more reasonable, like say, 4 or 5 cm.)

Regards,
Bill

OK Bill,

Thanks for the update. I hope this change works. More fine tuning.

dllfo, here are a couple of links to some interesting topics in the past about the Respironics BiPAP Auto. There was a man who used to post on the board, by the nickname of "-SWS". In my opinion, he's the most knowledgable person who has written posts about the technical aspects of any of these machines.

You might enjoy reading some of the speculative discussions from back when Respironics first announced the machine was being introduced.

Sep 18, 2005 subject: Respironics New BiPAP-Auto machine The discussion contained an email comment by -SWS, included with his permission.

Oct 29, 2005 subject: Respironics Bipap Auto First Night Impression
Topic started by Titrator. Includes several comments by a very knowledgeable (imho) "Guest" regarding how the machine works.

RG - thank you, I will read them. I like to download threads into MS Word, then I can highlight what I consider most important, etc. Plus I can take the
articles on the road. In June we are supposed to go up to the Anacortes, WA
area for a couple or three weeks...Hopefully I can breathe well up there.

I had my heated humidifier up and running last night. Slept great. 7 hours...
until the alarm went off. I did the reset to 4/16. This is the prescription my doctor sent out yesterday. I hope I save Tricare some money by doing it myself.

My wife says I was on my side this morning and it sounded like I had an
air leak. It may have been the exhaust....the "over flow" of air from the
nose mask. I will have to look at the software to see if it "saw" a leak.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): humidifier, Prescription

Just a comment about the algorithms used in the various machines (any brand). Their correct operation depends upon the input they receive from the sensors and upon the reliability of the hardware involved. Two identical machines running the exact same algorithms can and will give different results if one is having problems measuring the air flow for example. Or perhaps the motor speed regulation is a bit off on one. No machine is perfect, All operate within some tolerance.

That said, it seems to be a common problem for some people to be unable to breath in sync with some machines. I myself started with a bi-level device because I just could not breath out against my initial preaaure of 12. I had major problems with the sync issue and eventually kept moving IPAP & EPAP closer together untio I learned to breath with strait CPAP.

Was the problem with the machine, or with me? For me, it dosen't matter anymore. For others, you may have to experiment to find something that works for you. If you can try other equipment you may find one that works. It may be as simple as a different mask. If it is just a comfort issue and you can safely do so, eliminate the whole bi-level issue and work your way into strait CPAP. Simple is often better though autos are an exception.

Good luck. I hope everything works out for you.

Darth Vader Look wrote: You can all guess at what the problem is but until you hookup a logic analyzer, a multi-trace oscilloscope, computer with algorithm monitoring software (ie. the software used to produce the algorithm) and have the exact problem occur you are just guessing in the dark. [/url]

Passing through a few topics and I wanted to comment on this topic. I have not posted in this thread as any of the guests. It's a great thread with many great contrasting points by engineers and non-engineers. While I have a background as a development engineer unrelated to CPAP, the majority of what I have learned about sleep apnea and CPAP has probably come from non-engineers. I have learned a great deal from Rested Gal in the past and she even claims to have gleaned some of my knowledge in return. I have learned a great deal from many other non-engineers as well. My personal view is that an open forum is best thought of as a multidiscipline think tank, and no one should be excluded from participating in any of the threads. I also think that everyone benefits most in these discussions when contrasting views are very comfortably interleaved with respect for all members involved.

On the interesting topic of whether a premature EPAP "flip" is a defect or a design limitation. My hunch is this is one of those topics where semantics play a more important role to some posters than others. Reading between the lines I get the impression that DSM just may view design limitations and flaws as one undesirable category. And that Guest thinks there is a subtle albeit important underlying difference between the two. Bill highlights a product improvement mindset that I am very familiar with, that correctly strives to improve a product whether those shortcomings happen to be design limitations or flaws (design oversights). The bottom line is that all xPAP machines very likely contain both design limitations and design oversights.

So, when exactly is a "flip" a "flop" and when is a "flip" a "flub"? DSM observes a premature EPAP "flip" and knows fully well that it is a big "flop" regarding his sleep cycle. Therefore as an engineer he correctly marks it for improvement. Guest reads about the EPAP "flip" and correctly wonders if the "flip" is a genuine design "flub" or merely a design limitation relative to certain breathing patterns. I highlighted DVL's comment above because I think he's correct. I think all premature "flips" are "flops" that need to be improved upon, but not all "flips" are truly design "flubs". Rather some are equally disappointing design limitations.

A high level and likely very common example of an xPAP machine's design limitations have to do with the mathematical interpretation of a patient's airflow signal. Any patient's breathing pattern is actually a resultant composite of airway architecture, neurologically based autonomic respiratory nuances, sleep cycle disturbance, and consequently intervening breath control that is voluntary versus autonomic. Any one of these subcomponents that influence breathing patterns, in turn, are comprised of their own composite factors. In other words, breathing patterns across the human population can be quite diverse. Therein lies the xPAP designer's challenge. The very technical proposition of correctly interpreting all possible failing (physiologic) airway mechanisms from a composite airflow signal is wrought with inevitable statistical anomalies and other air flow signal interpretation challenges. For better or worse, today's xPAP algorithms suffer the shortcomings of airflow signals being "probability lumped" into categories relative to various airway closure and obstruction conditions.

That's where the concept of design limitation versus design flaw come back into the discussion. If an airflow signal is both characteristic and incorrectly probability lumped into the wrong category, then it is a design flaw. However, is an airflow signal is simply uncharacteristic for any reason whatsoever, then it will be misinterpreted as part of a design's limitation. Is there an important distinction between those two cases? Regarding the types of improvements Bill mentioned, no there is not. Both cases should ideally be improved throughout the development cycle. In the case of Guest's point, I have to agree there can potentially be an important distinction between the two. In the case of an engineer-based user committee interfacing with the manufacturers, I think the distinction is important as a matter of professional practice. In the case of consumer confidence being potentially misplaced in a product that is flawed versus suffering technical limitations, Guest thinks there is an important distinction. I respect that view whether I happen to agree with it or not. And after all, that is the essence of learning in its ideal form: respectfully considering new and even contrasting ideas.

In the case of DSM's premature EPAP flip. Is it a design flaw or is it a design limitation? I honestly don't know since I haven't been able to trace through the code in relation to those signals DVL pointed out. However, I will speculate that a near-zero-flow triggering threshold can be fooled by DSM's slow, controlled breathing from years of meditation coupled with the UltraMirage FFM's entrainment leak characteristics. My hunch is that Respironics would probably say they designed and tested their AutoBiPAP machine to be used with Respironics masks.

It sure is wonderful to see you back, -SWS, my friend!

-SWS wrote:It's a great thread with many great contrasting points by engineers and non-engineers. While I have a background as a development engineer unrelated to CPAP, the majority of what I have learned about sleep apnea and CPAP has probably come from non-engineers. I have learned a great deal from Rested Gal in the past and she even claims to have gleaned some of my knowledge in return. I have learned a great deal from many other non-engineers as well. My personal view is that an open forum is best thought of as a multidiscipline think tank, and no one should be excluded from participating in any of the threads. I also think that everyone benefits most in these discussions when contrasting views are very comfortably interleaved with respect for all members involved.

The very technical proposition of correctly interpreting all possible failing (physiologic) airway mechanisms from a composite airflow signal is wrought with inevitable statistical anomalies and other air flow signal interpretation challenges. For better or worse, today's xPAP algorithms suffer the shortcomings of airflow signals being "probability lumped" into categories relative to various airway closure and obstruction conditions.

That's where the concept of design limitation versus design flaw come back into the discussion. If an airflow signal is both characteristic and incorrectly probability lumped into the wrong category, then it is a design flaw. However, is an airflow signal is simply uncharacteristic for any reason whatsoever, then it will be misinterpreted as part of a design's limitation. Is there an important distinction between those two cases? Regarding the types of improvements Bill mentioned, no there is not. Both cases should ideally be improved throughout the development cycle. In the case of Guest's point, I have to agree there can potentially be an important distinction between the two. In the case of an engineer-based user committee interfacing with the manufacturers, I think the distinction is important as a matter of professional practice. In the case of consumer confidence being potentially misplaced in a product that is flawed versus suffering technical limitations, Guest thinks there is an important distinction. I respect that view whether I happen to agree with it or not. And after all, that is the essence of learning in its ideal form: respectfully considering new and even contrasting ideas.

-SWS,

Thank you for coming back, if only for a short while. As you can see, we needed you. I am not an engineer, but I appreciate being welcomed back into this thread (instead of being advised to keep out of it) by someone who is.

You summed it up so well. I think there is an important distinction between an issue being defined as a "flaw" vs. a "limitation." I think we should wield our terminology carefully, particularly as it pertains to newcomers. Imagine how disheartening it is to hear, as a brand new cpap-user trying to adapt to this therapy, "Your machine's algorithms are screwed up and this is a design flaw." (Not only disheartening, but factually incorrect.)

I like your suggestion of the word "limitation". Algorithms can't be all things to all people. That is a limitation.

Thank you, and may cooler heads prevail.

Guest wrote:You summed it up so well. I think there is an important distinction between an issue being defined as a "flaw" vs. a "limitation." I think we should wield our terminology carefully, particularly as it pertains to newcomers. Imagine how disheartening it is to hear, as a brand new cpap-user trying to adapt to this therapy, "Your machine's algorithms are screwed up and this is a design flaw." (Not only disheartening, but factually incorrect.)

I like your suggestion of the word "limitation". Algorithms can't be all things to all people. That is a limitation.

Thank you, and may cooler heads prevail.

Since my use of the word flaw is credited with starting this, I'll comment.

I'm quite comfortable with using the word limitation rather than flaw, and also with the categories outlined by DSM, but I will respectfully point out that this semantic subtlety is likely of little concern to a new BiPAP-auto user who, when starting therapy, finds that his new machine doesn't work for him. You'll have to trust me on this, since I am one of the 50% of new users who has discovered this "limitation" when starting my therapy. Regardless of what semantics are used to describe the issue, it also won't surprise me if more folks bring this issue up as more new BiPAP-auto users find their way to this forum. (Hopefully, those folks will have cooperative DME's which will swap their machines out for a different brand more in tune with their unique personal breathing styles.)

We can argue endlessly about whether or not this "limitation" is a fundamental limitation of the technique used, and therefore uncorrectable, or whether it lends itself to algorithmic adjustment, and is therefore easily correctable. (Personally, my guess is the latter.) The BiPAP-auto is after all a new machine using an entirely new airflow detection algorithm. As with automobile models the very first products off the production line tend to exhibit certain "limitations" that the users of the products have issues with. Some limitations are minor, some are major. Many are corrected early in the product cycle, but many are not corrected until the next model year, and a few, unfortunately, end up being fundamental limitations in a particular design and are uncorrectable.

As for the comment about cooler heads prevailing, Guest, I certainly hope so. It does seem to me though that the only emotional arguments being put forth here have been made anonymously. Perhaps that subtle semantic distinction is not entirely evident to our "guest(s)" though, who appear(s) unable to detach emotionally from the issues under discussion.

Regards,
Bill

NightHawkeye wrote:As for the comment about cooler heads prevailing, Guest, I certainly hope so. It does seem to me though that the only emotional arguments being put forth here have been made anonymously.

NightHawkeye.You must have missed the emotional arguments and personal attacks put forth by dsm. They are well-documented on page one of this thread.

SWS,

Welcome to the discussion. Your input is without doubt a great boost to the usefulness of the topic.

On the issue of terminology in describing 'situations', I tried to address this with some suggestions in the Cpap Users Group thread.

Let me paint a hypothetical...

On the one hand we can have a user who purchases a machine and seeks to use it. The user has heard good comments about this machine from people here on cpaptalk.

However, the user finds that with their mixed brands of mask, humidifier & machine, they are not getting what they expect from the way the machine works, in fact they begin to think that the good reports on the machine just don't match their observations...

At this point we can deduce the following ...

- User appears to have a problem (user certainly thinks so)
- The machine could be faulty
- The user could be faulty
- The use could be faulty
- So the 'perceived problem' can be from a number of possibilities
--o User not using the machine as it was designed
--o User has a unique combination of mask, hose, h/h, machine & breathing
--o and the machine was never tested with this particular combination before
--o Manufacturer's algorithms may be incompatible with the combination
--o Machine may be a defective unit

Lets say that the user in this case decides the machine must be defective & it is just bad luck. The user then obtains another new one of these machines & finds the same pattern. If the user already knows that a couple of other brands of machines do work well allowing that all else remains equal, , then the user may well begin to look at the 1st brand of machine and say, it may be 'deficient' or have some 'limitations' compared to the other brands in the similar configuration.

The conclusions that the user can come to include
--o Brand x has a limitation when working with this combination
--o Brands y & z work as expected
--o People should be made aware of this

The user goes onto a discussion forum & states they think they have found a problem with brand x but rather than find an interactive discussion on what might be possible causes of the perceived 'issue', 'problem', 'defect', 'situation' (chose your own term), the user merely gets told by some other posters that they never experienced this machine problem, but more to the point, get asked to not be making apparently disparaging remarks about brand x.

The user still has a 'problem' but is being asked not to talk about it as being a problem. The user may then wonder just what is going on.

How does one broach the subject of possible problems without talking about them.

It is a given, and perfectly reasonable that the user be advised to engage in trials & tests to see if all parties can better understand if in fact it is a design issue or a usage issue.

So in this discussion I am now asking how does a user even get to talk about the possibilities if the topic is sidelined or squashed before it gets started ?

Saying there can never be a problem makes no sense at all.
Saying that manufacturers never make mistakes is not viable
Saying that the user must prove the problem before discussing it is a catch-22 (an in my opinion is what is being argued by some people in this thread).

However, I do agree that we could adopt a code of discussion that defines 'issues', 'problems', defects', etc: - it seems to me that a common language for talking about such issues may help.

DSM

Yet again we have a courageous poster slipping a hood over their head to post a distortion ...

>>
NightHawkeye.You must have missed the emotional arguments and personal attacks put forth by dsm. They are well-documented on page one of this thread.
<<

Your courage in doing this is to be admired by all

D

Guest wrote:As for the comment about cooler heads prevailing, Guest, I certainly hope so. It does seem to me though that the only emotional arguments being put forth here have been made anonymously....You must have missed the emotional arguments and personal attacks put forth by dsm. They are well-documented on page one of this thread.

Are you referring to the lighthearted jib-jab offered by our well respected friend from the southern hemisphere? It's hard for me to condemn any comments offered in good faith by a signed poster. It's those that obscure their identity to make a comment for which the motivation should be questioned. How can one defend the appropriateness of their comments if they are not willing to stand behind them with their reputation?

wading thru the muck wrote:Are you referring to the lighthearted jib-jab offered by our well respected friend from the southern hemisphere?

Linda3032 wrote:Wow DSM,

I'm not really sure who your "Pollyana" is, but I sure hope you are NOT referring to RG. Because she is one of the most helpful, most knowledgeable, posters on this board. Plus, she is also the MOST polite. Her post was very respectful to Nighthawkeye in offering her "take" on the situation.

RG is the first to admit she is not an "engineer", nor has the most technical information here. But she is very knowledgeable about the causes and affects of cpap problems. The military has a saying KISS - keep it simple stupid. And my guess would be that the majority of the problems that newbies experience are "grass root" problems that can be solved by "the basics". Why worry about rocket science when you are trying to fix a lawn mower?

DSM, you talk about "stupid exchanges"? I don't think our "Pollyana" would ever have written such insulting words.