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Im all confused now. I thought Ozij made a succinct point earlier, but now its obvious you guys dont know what you are talking about.

All I want to know is if I develop apneas on a Resmed Autoset Vantage APAP, with a minimum pressure setting of 10, will it be wipedout? Or will the machine say "whoa there, Silver, we dont want to start up or respond to central apneas."

I should just go ask Resmed themselves...thats what I usually do. Straight lines are best, get it from the horses mouth.

Eric

[quote="MrGrumpy"]Im all confused now. I thought Ozij made a succinct point earlier, but now its obvious you guys dont know what you are talking about.

All I want to know is if I develop apneas on a Resmed Autoset Vantage APAP, with a minimum pressure setting of 10, will it be wipedout? Or will the machine say "whoa there, Silver, we dont want to start up or respond to central apneas."

I should just go ask Resmed themselves...thats what I usually do. Straight lines are best, get it from the horses mouth.

Eric

viewtopic.php?p=37380#37380

WillSucceed wrote:Posted: Wed Sep 07, 2005 10:35 pm Post subject: ResMed S8 Vantage EPR

I called ResMed to see if they could give me some information regarding this new device but, as it is not yet launched, their answer was "nyet."

Specifically, I wanted to know:
1) Is the algorithm running this machine is the same as that which runs the Spirit?
2) Can the Expiratory Pressure Relief be disabled if the user finds it to be unhelpful?
3) Can the machine can be set to function in straight CPAP mode if desired?
4) Does the machine record/provide data for software analysis?

Two days later a reply was received:
viewtopic.php?p=37575#37575

dsm wrote:Posted: Fri Sep 09, 2005 12:55 am Post subject: ResMed replys

Following answers came to me from ResMed Worldwide HQ in Sydney.
*******************************************************

I would be most grateful if someone could answer these particular questions
for me ...

1) Is the algorithm running this machine is the same as that which runs the
Spirit?

>>Same. It's the hardware only that is different.<<

2) Does the S8 offer a feature called Expiratory Pressure Relief ?

>>YES<<

3) If yes, can the Expiratory Pressure Relief be disabled if the user finds
it to be unhelpful?

>>YES, ERP is only available in CPAP mode and can be disabled if not required.<<

4) Can the S8 Autoset machine can be set to function in straight CPAP mode
if desired?

>>YES<<

5) Does the S8 Autoset machine record/provide data for software analysis?
(I have seen that the S8s can use a datacard that appears slightly larger
than a memstick, what information is put on the datacard & can I buy that software and the required reader to analyse the data)

>>YES, up to 180 sessions of usage, pressure, leak and events data as well as 5 nights of detailed data (Night Profile). The software and datacard already can be purchased from ResMed.<<

Cheers

DSM

UPDATE# corrected typo in ans to Q5 (typo was in the reply as sent)

Eric, you can ask for John Simon, of Resmed. He surely knows what he is talking about.

-SWS wrote:
I don't think I agree with the statement that people having apneas resolved by CPAP higher than 10 cm are ill-served by A10. Specifically, it would be those people who atypically have no snore and no FL precursors and require apnea resolution at pressures higher than 10 cm who would be poorly served by A10. To simply meet that atypical failing requirement for just a small yet significant portion of the night still means that A10 is probably not your best choice. But as Bill correctly points out, IMHO, all the APAP algorithms have their respective little efficacy shortcomings that tend to be manufacturer-specific.

I ain't sayin' I'm right. I'm just sayin' that's my opinion. .

Ok, you have all thoroughly confused the noobie now...

I can kind of follow along, but how much of this stuff is really important?

Needsdecaf wrote:Ok, you have all thoroughly confused the noobie now...

I can kind of follow along, but how much of this stuff is really important?

The important stuff for a person who wants to decide what to buy:

1. An automatic (self adjusting machine) can function perfectly well as fixed pressure machine.
   
   A fixed pressure machine can never fuction as a self adjusting machine.
   
   All automatic machines have algorithms (rules) defining how they identify your breathing events and how they respond to them.
   
   The rules for the various machines are different.
   
   Some - Respironics's automatic machines have pressure relief on exhalation. The others do not.
   
   There are no hard and fast rules about whether you will do better on fixed pressure, or on pressure the varies in response to your breathing events. The fact the a majority respons one way or the other is meaningles if you belong to the minority. You need the treatment that is good for you.
   
   Because of the above, I would buy a self adjusting machine. You can always run it as fixed - should it turn out you don't do well on auto mode.
   
   There are no hard and fast rules about which treatment algorithm will be better for you if you need continous adjustment.
   
   If you have a chance to try different autos - jump on it.
   
   If you don't.... well, lets hope your first machine is good for you. If its auto mode is not good for you put it on straight pressure. If that is no good, you may have to try another company's auto.

I wish it were simpler....
O.

Yes, what ozij said.

Different manufacturers use different APAP algorithms and of course we all know people are also different. Some respond well to any algorithm, others only to specifc one(s), while others still to none at all and only to fixed CPAP.

The reason for getting an APAP is to arm yourself with the most options (platinum standard) ... and IMO, the Repironics AFLEX machine offers the most options. Some of the members posting to this thread have tried two or more of the different APAPs and of course one of em just likes to grumble.

How much is really important depends on how deep you want to get into the understanding of OSA treatment. So you can take the advice of the more experienced forum members (who do know what they are talking about and in many cases know more about this stuff than the sleep professionals), or you can put your engineering curiosity to work and start researching and experiment on your own by trialing them all yourself to see what works best for YOU.

ozij wrote:
The important stuff for a person who wants to decide what to buy:

1. An automatic (self adjusting machine) can function perfectly well as fixed pressure machine.
   
   A fixed pressure machine can never fuction as a self adjusting machine.
   
   All automatic machines have algorithms (rules) defining how they identify your breathing events and how they respond to them.
   
   The rules for the various machines are different.
   
   Some - Respironics's automatic machines have pressure relief on exhalation. The others do not.
   
   There are no hard and fast rules about whether you will do better on fixed pressure, or on pressure the varies in response to your breathing events. The fact the a majority respons one way or the other is meaningles if you belong to the minority. You need the treatment that is good for you.
   
   Because of the above, I would buy a self adjusting machine. You can always run it as fixed - should it turn out you don't do well on auto mode.
   
   There are no hard and fast rules about which treatment algorithm will be better for you if you need continous adjustment.
   
   If you have a chance to try different autos - jump on it.
   
   If you don't.... well, lets hope your first machine is good for you. If its auto mode is not good for you put it on straight pressure. If that is no good, you may have to try another company's auto.

I wish it were simpler....
O.

You read me wrong, sorry.

I can understand that what has been discussed distills down into what you posted above.

What I don't understand is how important IS all this "responding to low flow events", etc.? Seems to me that as you said, many people run straight CPAP and have great treatment so all of this adjusting to counter apneas is only useful for the way certain people respond. Or maybe it's all in their head.

Yes, I sure did misunderstand you.
I doubt its in people's heads. Bad treatment does so much harm all of you, that good treatment is noticeable....
Let us know what you decide, and how it works out for you!
O.

Needsdecaf wrote:

ozij wrote:
The important stuff for a person who wants to decide what to buy:

1. An automatic (self adjusting machine) can function perfectly well as fixed pressure machine.
   
   A fixed pressure machine can never fuction as a self adjusting machine.
   
   All automatic machines have algorithms (rules) defining how they identify your breathing events and how they respond to them.
   
   The rules for the various machines are different.
   
   Some - Respironics's automatic machines have pressure relief on exhalation. The others do not.
   
   There are no hard and fast rules about whether you will do better on fixed pressure, or on pressure the varies in response to your breathing events. The fact the a majority respons one way or the other is meaningles if you belong to the minority. You need the treatment that is good for you.
   
   Because of the above, I would buy a self adjusting machine. You can always run it as fixed - should it turn out you don't do well on auto mode.
   
   There are no hard and fast rules about which treatment algorithm will be better for you if you need continous adjustment.
   
   If you have a chance to try different autos - jump on it.
   
   If you don't.... well, lets hope your first machine is good for you. If its auto mode is not good for you put it on straight pressure. If that is no good, you may have to try another company's auto.

I wish it were simpler....
O.

You read me wrong, sorry.

I can understand that what has been discussed distills down into what you posted above.

What I don't understand is how important IS all this "responding to low flow events", etc.? Seems to me that as you said, many people run straight CPAP and have great treatment so all of this adjusting to counter apneas is only useful for the way certain people respond. Or maybe it's all in their head.

It's about options ... not what's in your head.

If you feel lucky that you will only need CPAP and your titration was right on the bull's eye, and your OSA pressure needs will never again change, and your apnea is the same whether you sleep on your side or your back, and you don't take and nerver will take medications or drink alcohol, and you won't suffer from aerophagia, and you know you will always tolerate the needed pressure and will never need any other kind of optional pressure comforts ... then do as grumpy does and use the gold standard CPAP.

Think of buying an APAP as a kind of like buying an insurance policy.

Snoredog wrote:

-SWS wrote: ...I'm still of the opinion this can happen two ways: 1) passive relaxation of muscle mass (remiss active airway maintenance), and 2) reflexive partial airway closures (neurological control gates activated toward closure).

I think gravity predominately drives scenario one and defensive/reflexive neurology drives scenario two. And I think scenario two is more prominent in OSA than medicine has recently suspected. Now that's wild man speculation!

Scenario one is an easy job for CPAP but sometimes scenario two can be "reflexively challenging" for ordinary PAP to resolve. I suspect cyclic alternating pattern (CAP) may even be characteristically hyperactive during reflexive scenario two. Again, pure wild speculation.

I'm seeing those FL's at higher pressure as residual by nature...

but my question is too complicated for me to ask in order to obtain an answer, so I'll ask it later

I agree about the likelihood of many/some flow limitations being "residual" at higher pressures. But here's where I personally get to wondering about scenario two: tissue mass is a constant (not variable) for Wally and others when obstructive A, H, and FL happen to nicely resolve at lower pressures throughout the sleep session.

The mass to be stented via pressure never changes throughout the night. Rather neuromuscular activity itself is what continuously changes throughout the night. The status quo diagnostic assumption has always been that this neuromuscular airway change is almost always a result of passive blocking, shifting, or simply a lack of neuromuscular vigilance regarding the maintenance of the airway. I agree that in these cases especially partially stinted apneas can manifest as "residual flow limitations".

However, when you start to see episodic short bursts of flow limitation, unaccompanied by typical obstructive tell-tale precursor events (let alone in deeper stages of sleep), then you have to start wondering if defensive neurological control gates aren't firing in at least some of these cases. And you have to start wondering why maladaptive neurology might be orchestrating what is likely a reflexive response.




Mr. Grumpy, I wonder if your medication-induced AI spikes caused some fairly atypical airway closures that A10 was simply not designed to cope with. By fairly atypical I'm wondering about algorithm-stumping factors such as: 1) the suddenness of those airway closures, 2) the neuromuscular persistence or "steadfast heaviness" of those airway closures, 3) whether they were proceeded by typical snore or FL precursors that the A10 algorithm relies on to effectively preempt apneas requiring "reactive resolution-pressures" above 10 cm.

If you call Resmed to get our thinking squared away, please tell them that -SWS says hello!!





[on edit: "stented" versus "stinted" typo corrected much thanks to a very kind PM from Ozij!]

Needsdecaf,

You started this thread off with asking a simple question about which machine had the most "bells & whistles"........and ended up with the additional information of knowing what all those "bells & whistles" sound like.

My answer still remains the Respironics M Series Auto w/A-Flex. You can turn on or off whatever features you do or do not want to use. And, the software is easy to understand.

Best wishes,

Den

[quote="Wulfman"]Needsdecaf,

You started this thread off with asking a simple question about which machine had the most "bells & whistles"........and ended up with the additional information of knowing what all those "bells & whistles" sound like.

My answer still remains the Respironics M Series Auto w/A-Flex. You can turn on or off whatever features you do or do not want to use. And, the software is easy to understand.

Best wishes,

Den

First of all, we were all in your shoes at one time......this was all new and overwhelming to us. If you'll notice, a great many of us have backgrounds in computers and other sciences. If you ask us what time it is, there's a better-than-average chance that you'll also find out how the clock was made, too. I guess that's just our nature......I used to have a boss that would tease me about doing that......giving him more information than he needed.

I seriously doubt that you'll have problems with the Respironics machine.....they've also recently re-designed the humidifier, too. With regard to the ResMed machines, there's the lack of exhale relief in Auto mode and from the comments I've seen on the forum, they don't seem to put out as much humidity as the Respironics machines do. People have commented that they really have to crank them up to feel any humidity. I don't use heated humidity with my setup......just cool pass-over, which keeps my nasal passages open.

Personally, I like the Legacy (Pre-M) models, but unfortunately they aren't that easy to find anymore, in "new" condition. And, I found that fixed pressure (CPAP) mode works best for me. I've tried Auto mode, but it has a tendency to disturb my sleep with the changing pressures and I end up with a higher AHI. But, I do like the C-Flex exhale relief.
So, it's a matter of preferences and trying different things to see what works best.....but you have to have a machine that has enough options. In my opinion, data capabilities are of primary importance before all else. "You can't tell where you're goin' if you don't know where you've been".


Den

-SWS wrote:You just piqued my curiosity with that quote, Bill. Smile Actually, that section does not describe the machine's response to an apnea. Rather that section describes the algorithm's premptive search for optimum versus critical pressure. That little pre-emptive search toward an optimum "pressure holding pattern" occurs when the algorithm is not otherwise preoccupied responding to a sleep event, NR, variable breathing, etc. (all different parts of the algorithm).

OK, -SWS, I'll start at the top, if I may, rather than simply quoting the summary section info.

Patent 5,645,053, column 16, line 27, titled: System Operation

Patent 5,645,053 wrote:A more detailed discussion of overall system operation and in particular, implementation of a preferred testing protocol, will now be provided. Figure 7 shows a general flow diagram of an exemplary system operation. In block 50, the system is powered for use. In block 52, the system is initialized.

Figure 7, the basis for comments in my earlier post, describes the "overall system". Figure 7 has two main branches; a test branch and a non-test branch as can be seen in the figure below. Test, as used by Respironics, means testing to see if pressure changes are needed (i.e., the heart of the APAP algorithm).

Patent 5,645,053 wrote:Following start-up and initialization, the adaptive control system operator enters a non-testing mode as indicated by block 54. While in the non-testing mode, the operator continuously evaluates whether a testing mode can be entered to update Pcrit and Pcrit. (sic)

Note: There appears to be a typo in the patent here. I believe the second Pcrit should have been Popt.

It appears that updates to Pcrit and Popt only occur when the system is operating in the test branch (left hand side of Figure 7).

Patent 5,645,053 wrote:In a preferred embodiment, a test mode can be entered only after a predetermined number of breaths have occurred without the detection of breathing instabilities (e.g., apnea, hypoventilation or variable breathing).

Seems clear enough so far. No testing allowed when an apnea is present. Except that ...

Patent 5,645,053 wrote:After five counts (i.e., 50 breaths), a decision is automatically made to enter a testing mode even though breathing instabilities may exist (block 56 ).

The time period corresponding to 50 breaths is very long, on the order of minutes, and certainly not the quick response to apnea that some would like to believe.

Block 58 is where many of the details are buried, but it is summarized succinctly ...

Patent 5,645,053 wrote:After two intervals (i.e., 20 breaths), if all rules are satisfied (i.e., no breathing instabilities) the testing protocol of block 58 is initiated. However, if all rules are not satisfied (i.e., apnea, hypoventilation and/or variable breathing is detected by decision blocks 60, 62 and 64 ), testing is delayed by increasing the maximal interval limit up to three times (block 66 ) and the non-test interval count is incremented (block 68 ). The system then remains in the non-testing mode for 10 more breaths.

Still seems clear ... Testing for pressure changes is not allowed when an apnea is present, except after a very long delay. This is elaborated on in the following (added emphasis mine).

Patent 5,645,053 wrote:During a testing mode, a search is first made for Pcrit. Once Pcrit has been determined, a search is made for Popt. In testing mode, the system continuously checks for apnea, hypoventilation and/or variable breathing (blocks 70, 72 and 74 ). If any of these instabilities are detected (or any changes in these values are detected in the case where the test mode was entered after 50 breaths), testing is stopped (block 76 ). The non-test interval count is reset to zero (block 78 ) and the system returns to a non-test mode.
At this point, because neither Pcrit and Popt (sic) have been determined, the system uses the last, accurately determined Popt during the non-test mode (block 76 ). Alternately, the system can be set up such that block 76 represents use of a Popt determined as an average of prior (e.g., two) accurately determined Popt. In yet another embodiment, an experimentally determined Popt previously specified by a sleep lab specialist can be used.

It appears that the patent description of operation for Pcrit and Popt is not in agreement with your summary, -SWS.

-SWS wrote: You just piqued my curiosity with that quote, Bill. Actually, that section does not describe the machine's response to an apnea. Rather that section describes the algorithm's premptive search for optimum versus critical pressure. That little pre-emptive search toward an optimum "pressure holding pattern" occurs when the algorithm is not otherwise preoccupied responding to a sleep event, NR, variable breathing, etc. (all different parts of the algorithm).

Specifically, the Remstar Auto periodically performs little pressure-delta tests, searching for tell-tale variations in the flow signal. All toward differentiating an "optimum" holding pressure versus understanding a "critical" pressure threshold below which subtle hints of adverse flow variations are detected. The idea is for the algorithm to detect those subtle flow variations and to not cross below that threshold---rather to keep the "pressure holding pattern" at just a slightly higher "optimum". This part of the algorithm speaks of achieving the lowest and presumably most comfortable holding pressure that is safely afforded.

I think Rested Gal is right about that three-pressure-increment limit in direct response to an apnea. After that limit of three pressure increments in response to an apnea, it is either resolved (in three or fewer pressure attempts) or it is labeled as non-responsive (NR).

Note: The preceding quote was expanded in a later edit to avoid potential misunderstanding.

Assuming that by "optimum" you mean Popt and by "critical" you mean Pcrit, the patent description for determining Pcrit and Popt is not nearly so rosy (i.e., responsive) as your description, -SWS. When an apnea occurs, testing simply ceases and no further pressure changes are allowed until a very long delay has passed.

No argument that the algorithm is pre-emptive, but the point being debated was what happens when an apnea occurs.

The other algorithm flowcharts, Fig 8a-c, simply provide more details of the testing algorithm in Figure 7, block 58:

Patent 5,645,053 wrote:FIGS. 8a-c show a more specific flow chart of an exemplary testing protocol represented by block 58 in FIG. 7. The steps of the FIG. 8 flow chart are first executed to determine Pcrit. Afterwards, the FIG. 8 steps are repeated to identify Popt.

I don't see that Pcrit and Popt are determined anywhere else in the Respironics algorithm, -SWS. Is there another reason to think the Respironics algorithm responds more quickly to apnea events than as described above in the Respironics APAP patent?

Did I miss something?

Regards,
Bill

[quote="Wulfman"]First of all, we were all in your shoes at one time......this was all new and overwhelming to us. If you'll notice, a great many of us have backgrounds in computers and other sciences. If you ask us what time it is, there's a better-than-average chance that you'll also find out how the clock was made, too. I guess that's just our nature......I used to have a boss that would tease me about doing that......giving him more information than he needed.

I seriously doubt that you'll have problems with the Respironics machine.....they've also recently re-designed the humidifier, too. With regard to the ResMed machines, there's the lack of exhale relief in Auto mode and from the comments I've seen on the forum, they don't seem to put out as much humidity as the Respironics machines do. People have commented that they really have to crank them up to feel any humidity. I don't use heated humidity with my setup......just cool pass-over, which keeps my nasal passages open.

Personally, I like the Legacy (Pre-M) models, but unfortunately they aren't that easy to find anymore, in "new" condition. And, I found that fixed pressure (CPAP) mode works best for me. I've tried Auto mode, but it has a tendency to disturb my sleep with the changing pressures and I end up with a higher AHI. But, I do like the C-Flex exhale relief.
So, it's a matter of preferences and trying different things to see what works best.....but you have to have a machine that has enough options. In my opinion, data capabilities are of primary importance before all else. "You can't tell where you're goin' if you don't know where you've been".


Den