Resmed vs. Respironics - Help

Wulfman wrote:You might want to read these two links about the different "TYCO" companies:

http://en.wikipedia.org/wiki/Tyco_Toys

http://en.wikipedia.org/wiki/Tyco_International

Thanks much, Den! Interesting links for sure. Despite my attempt at humor I already knew that several Tyco companies existed. As a side note, though, I still have my Tyco train set from way back when I was a tyke. Little did I know back then that I would some day have a Tyco 420e.

Maybe I should put those two together to make a little HO-scale train with Tyco air brakes... .

Hose_Head wrote:I guess my question wasn't clear. To re-phrase it, for the Respironics M Series, how easy, or difficult, is it to changeover from use of the built in heated humidifier to use of an external Fisher Paykel or similar heater humidifier. My understanding is that the entire HH assembly must be removed. Is this true?

Oh, that was my fault for not understanding. You were clear now that I reread your original question more closely.

Right...it's true that the M machine must be completely removed from the entire integrated humidifier (humidifier platform and all) ... AND... you have to put a "cap" thingy on the machine, where the main air hose would attach to the machine. The cap thingy should come with the humidifier.

The cap is NOT used when the integrated humidifier is being used.

The cap IS used when the machine is being used with either no humidifier at all, or with a stand-alone humidifier like the F&P HC 150. If using the F&P humidifier, the connector hose that comes with the F&P will attach the F&P to the cap thingy on the M machine. The main air hose will be attached to a second port on the F&P.

Sounds like hooking up a DVD player, doesn't it? LOL!!

It's easy, once you get the knack of the first-time-surprising (feels like you're going to break something) amount of force it takes to lift the front of the machine up to make it kind'a pop upward. Then you can easily pull the machine forward to remove it from the humidifier platform.

Just don't lose the cap thingy. Think of it as a car gas tank cap. Remember where you left it.

-SWS wrote:

Wulfman wrote:You might want to read these two links about the different "TYCO" companies:

http://en.wikipedia.org/wiki/Tyco_Toys

http://en.wikipedia.org/wiki/Tyco_International

Thanks much, Den! Interesting links for sure. Despite my attempt at humor I already knew that several Tyco companies existed. As a side note, though, I still have my Tyco train set from way back when I was a tyke. Little did I know back then that I would some day have a Tyco 420e.

Maybe I should put those two together to make a little HO-scale train with Tyco air brakes... .

HA! I wish I still had some of the stuff I had when I was a kid.

It even got more complicated when Tyco HEALTHCARE became Covidien. SHEESH!

Den

-SWS wrote:As a side note, though, I still have my Tyco train set from way back when I was a tyke. Little did I know back then that I would some day have a Tyco 420e.

Maybe I should put those two together to make a little HO-scale train with Tyco air brakes...

Keep IFL1 turned on, so the little train can climb steep hills faster! Or, do I mean pick up speed on the plateaus? Well...whatever!! What the heck, try it both ways.

-SWS wrote:Bill, I think you just missed the correct patent description. That's all.

OK. Moving on to the next Respironics patent ... Perusing patent 7,168,429 B2 has been an interesting exercise so far. Especially noteworthy is that this patent includes a listing of all 14 other APAP patents (prior art) and makes a blanket statement that all the other algorithms are reactive to events rather than pre-emptively warding off events. That is, all other patents except for one, patent 5,645,053, the one I reviewed yesterday.

Patent 7,168,429 B2 wrote:All of these conventional pressure support systems, with the possible exception of U.S. Pat. No. 5,645,053 to Remmers et al., are reactive to the patient's monitored condition. That is, once a condition occurs that indicates abnormal breathing, the system alters the pressure support system to treat this condition.

The list was intended to be all-encompassing and includes patents for ResCare, ResMed, Puritan-Bennett, Respironics and Universal Technologies. (I don't know who they are now.)

The only patent stated to exhibit pre-emptive operation (albeit in a qualified manner) is the one I reviewed yesterday. If this statement can be trusted at face value, it would seem to be a serious indictment of shortcomings with the other APAP algorithms. (I'm not sure whether a patent examiner would care much about the accuracy of such posturing though.)

The point I was trying to make yesterday about APAP machines not attempting to clear apneas as soon as they have occurred has its origin in simple physics. Like a cork in a bottle, the tongue falling into the back of the throat is likely to be pushed more tightly into the throat by a pressure increase.

According to the description provided in Patent 7,168,429 B2, the new Respironics algorithm, like its predecessor, also still does not respond instantly to apneas. The relevant details are from column 19, line 48

Patent 7,168,429 B2 wrote:In a presently preferred embodiment of the invention, A/H monitor 166 will issue a request for control to request processor 106 if two apnea events or if two hypopnea events, as determined in the manner discussed above by A/H detector 164, occur within a predetermined period of time. In a presently preferred embodiment, this period of time is a three minute moving window.

This foregoing section describes the apnea/hypopnea monitoring layer. Any response to apneas and hypopneas cannot be initiated until this layer takes control. It is clear in the description that this layer doesn't take control until after two apnea events or two hypopnea events have been detected.

The length of time required for this layer to take control appears to be relatively long. Apnea detection time is elsewhere defined as 10 seconds, but no default apnea event time-out is listed. Conceivably then a single apnea event could be well over a minute in duration. A single apnea, however, would not be sufficient to prompt an increased pressure response by the APAP though, at least according to the foregoing patent description. Consequently, it seems unlikely that any apnea response would be likely to occur in less than a minute or so, more likely a couple of minutes. By that time most apneas would have been cleared by the patient himself (or herself) awakening somewhat.

So, if the A/H layer doesn't take control to raise pressure immediately when an apnea occurs, just what is the machine doing? The basic answer appears to be maintaining relatively constant pressure, although there are a number of seemingly minor caveats associated with that.

So that's how I see things stacking up after looking at this patent for a few hours. Comments, -SWS?

Regards,
Bill

NightHawkeye wrote:The point I was trying to make yesterday about APAP machines not attempting to clear apneas as soon as they have occurred has its origin in simple physics. Like a cork in a bottle, the tongue falling into the back of the throat is likely to be pushed more tightly into the throat by a pressure increase.

There is soft tissue in the back of the throat too. Nasal cpap air at the right pressure (think: "minimum pressure being set reasonably high enough in the first place") can push the soft tissue of the back of the throat out of the way. As well as push the soft tissue of the back of the tongue forward toward the mouth.

I don't think a "cork in a bottle" analogy applies very well to what would happen with a relaxed, fallen back tongue during nasal cpap treatment (or even oral cpap treatment when breathing through the mouth with a FF mask) given the softness of the tissues involved with the tongue and back of throat. Perhaps my idea (which could be wrong) has its origin in the physics involved with simple anatomy and soft tissue?

If a "cork in a bottle" thing was happening, I'd think that would be popping up (pun intended) in sleep study titrations all over the place, when apneas are still happening at lower pressures and the sleep techs are increasing the pressure to clear them. Titrations going on with the patients preferably sleeping on their backs in order to see worst case scenario...allowing the tongue to loll back well and truly.

I'd think sleep techs would be commenting on their message boards (like over at binary) about "Watch out for that cork in a bottle problem!" when they increased pressure in the presence of an obstructive apnea.

rested gal wrote:
<snip>

f a "cork in a bottle" thing was happening, I'd think that would be popping up (pun intended) in sleep study titrations all over the place, when apneas are still happening at lower pressures and the sleep techs are increasing the pressure to clear them. Titrations going on with the patients preferably sleeping on their backs in order to see worst case scenario...allowing the tongue to loll back well and truly.

<snip>

Hi RG,

I just came on this thread after catching up from a nice long holiday break. Re the point about 'sleep techs increasing pressure to clear them' I just wanted to add some thoughts ...

The quoted statement can create an impression for apnea newcomers that a sleep tech (and also an auto cpap) can actually 'clear them' in real time. By this I am saying one could think you are meaning a sleep tech can clear an apnea block as it happens, when in fact the sleep tech is merely raising the pressure to better hold the airway open (splint it) to 'preempt' future blocks. I am not aware of sleep techs ever attempting to 'clear them' in a way that involves instantaneous increase of pressure to open the sleeper's throat when an apnea is actually happening.

Bill's point is that pressure applied while someone is having an OSA event, could for some people, compound the block (reinforce it). I am sure this is covered in some studies done on the issue of applying pressure while a full OSA event is in progress.

So the reason I raise this is that I believe that some people, did and still do, believe that APAP units clear individual apneas as they actually occur rather than slowly raising pressure to try to stop subsequent ones. Raising pressure to eliminate OSA events is a reactive process that seeks to preempt future OSA events. I believe this applies to sleep techs as well as APAPs.

Cheers

DSM







I think the comment

According to this, DSM, no apneas are ever cleared by pressure and the shorter apneas, experienced when the pressure is right are only the result of the airway being properly, preemptively stented by the fixed pressure.

SAG - we need you input on this one: Do sleep techs try to resolve apneas they see, or do they only raise pressure to pre-empt the next onea?

And what about the "cork in the bottle" analogy? I am more convinced by Rested Gal, who pointed out that the bottle is as soft as (maybe even softer) than the cork. But I'm sure we'd all love to hear from one who knows.


O.

I didn't mean to give the impression that I thought sleep techs during a titration go flipping the pressure up instantly at the very moment they see each and every single apnea occur.

If they were presented with a block of apneas happening, I'd think they'd move the pressure up during those apneas, but maybe not...maybe they'd wait until those subsided before proceeding to the next pressure up.

However, if sleep techs do wait it out even when a solid block of apneas are happening, I just don't think it would be because they feared causing "cork in a bottle."

ozij wrote:According to this, DSM, no apneas are ever cleared by pressure and the shorter apneas, experienced when the pressure is right are only the result of the airway being properly, preemptively stented by the fixed pressure.

SAG - we need you input on this one: Do sleep techs try to resolve apneas they see, or do they only raise pressure to pre-empt the next onea?

And what about the "cork in the bottle" analogy? I am more convinced by Rested Gal, who pointed out that the bottle is as soft as (maybe even softer) than the cork. But I'm sure we'd all love to hear from one who knows.


O.

Ozij,

'no apneas are ever cleared by pressure '


This is again ambiguous and a confusing point & I am not clear what reasoning leads to it

An actual gag or block where the sleeper's lungs are attempting to suck in air but can't get any due to the throat closing shut (with a vacuum created in the downside of the airway) is not usually cleared by a sleep tech or an Auto - both will normally allow the sleeper to work through such a block but will bump up pressure a little and see if another occurs. When no more appear to occur within a normal time frame (and sleeping pattern) they will under normal circumstances set the pressure as the minimum splinting needed to prevent actual blocks. I believe there are docs about the potential harm of increasing pressure immediately when a sleeper is in the middle of a full OSA block.

This is how I understand the process works.

Cheers

DSM

rested gal wrote:I didn't mean to give the impression that I thought sleep techs during a titration go flipping the pressure up instantly at the very moment they see each and every single apnea occur.

If they were presented with a block of apneas happening, I'd think they'd move the pressure up during those apneas, but maybe not...maybe they'd wait until those subsided before proceeding to the next pressure up.

However, if sleep techs do wait it out even when a solid block of apneas are happening, I just don't think it would be because they feared causing "cork in a bottle."

RG,

Agree - I was sure you meant a pattern of OSA events

Re sleep techs waiting out real time events - perhaps the better words to describe 'block of apneas' is 'pattern of OSA events' - 'block' really does have a specific meaning as in 'blockage' vs using 'block' meaning a 'group'.

Cheers

DSM

rested gal wrote:I don't think a "cork in a bottle" analogy applies very well to what would happen with a relaxed, fallen back tongue during nasal cpap treatment (or even oral cpap treatment when breathing through the mouth with a FF mask) given the softness of the tissues involved with the tongue and back of throat. Perhaps my idea (which could be wrong) has its origin in the physics involved with simple anatomy and soft tissue?

I agree with you, RG. The analogy is far from perfect, and I struggled whether to even state it. The cork-in-a-bottle analogy is so simple, however, that it conveys the essence of the potential problem clearly. For that reason I did include it, knowing full well that you would likely challenge its validity. And, I'll also add, I believe you are correct to do so.

At any rate, however, the analogy serves merely to introduce the concern. The main question to be answered was: "How does the Respironics APAP algorithm respond to apneas?" I formulated a preliminary conclusion in my prior post, based entirely on specific information contained in the Respironics patent I was directed to by -SWS.

I won't even say that my conclusion is correct at this point. I'm certainly no expert on the subject matter. I have, however, in the interest of transparency, documented how I reached the conclusion I did, so that others can modify it as appropriate, hopefully providing a similar level of transparency if they choose to do so.

Regards,
Bill

Hi DSM,

Good to hear from you.

dsm wrote:Bill's point is that pressure applied while someone is having an OSA event, could for some people, compound the block (reinforce it). I am sure this is covered in some studies done on the issue of applying pressure while a full OSA event is in progress.

I recall you bringing up the subject a couple of years ago, DSM, although I also recall that universal agreement was never achieved among the discussion participants. I would like to credit you, DSM, for bringing the matter to my attention back then.

Attempting to avoid acrimony, I opted not to reference the earlier discussions, however. Instead, a fresh start on the subject seemed appropriate, letting the patents themselves spell out exactly how the machines respond.

Regards,
Bill

DSM, how was the car show? And welcome back!

NightHawkeye wrote: Especially noteworthy is that this patent includes a listing of all 14 other APAP patents (prior art) and makes a blanket statement that all the other algorithms are reactive to events rather than pre-emptively warding off events. That is, all other patents except for one, patent 5,645,053, the one I reviewed yesterday.

Bill I'm no expert in patent writing either. But I have noticed most of the xPAP patents cite the background of the invention as well as examples of the "prior art". I think this is typically done by the companies to facilitate assignment into the correct patent division. I bet it subsequently helps the reviewing patent officer(s) with their own comparative research toward final case disposition as well. My hunch is the companies simply want to make the patent approval process move along as efficiently as possible.

NightHawkeye wrote:The list was intended to be all-encompassing and includes patents for ResCare, ResMed, Puritan-Bennett, Respironics and Universal Technologies. (I don't know who they are now.)

Didn't that last company have something to do with the movie studios... or universally appealing shavers or something like that?

NightHawkeye wrote:The only patent stated to exhibit pre-emptive operation (albeit in a qualified manner) is the one I reviewed yesterday. If this statement can be trusted at face value, it would seem to be a serious indictment of shortcomings with the other APAP algorithms. (I'm not sure whether a patent examiner would care much about the accuracy of such posturing though.)

That one surprises me too. It really sounds more like posturing to me as well. It's definitely not an accurate assessment IMO.


Before going any further, I'd like to mention that the "Auto-CPAP Control Layer" contains that borrowed and significantly modified functionality from the old HealthDyne patent you cited, Bill. Interesting that in 1993 it was the heart of an APAP algorithm. Here it's the lowest-priority control layer toward determining an effective yet lowest possible "pressure holding pattern". Going from "heart of the algorithm" to eighth place on the priority list speaks of some very significant algorithmic evolution over the years IMHO.

NightHawkeye wrote:The point I was trying to make yesterday about APAP machines not attempting to clear apneas as soon as they have occurred has its origin in simple physics. Like a cork in a bottle, the tongue falling into the back of the throat is likely to be pushed more tightly into the throat by a pressure increase.

Well, I personally think/hope the days of acrimony in our APAP discussion groups are long gone. I know for certain those days are long gone regarding the good folks who are in this discussion now.

Because we now can compare our views without getting frustrated, I couldn't wait for you to discover that paired A+A or H+H requirement. I was chuckling like a mischievous child as I was waiting for you to read that part.

Using some of the old colloquialisms from past discussions, I think we all agree (and have agreed for some time) that an APAP doesn't just "pop up and readily shoot an apnea blockage down". Presently I don't want to fall into the trap of debating semantics either, when I think everybody is viewing and conceptualizing pretty much the same thing. I think the APAP is directly responding to apneas, but very slowly and cautiously for good reason. Respironics very clearly calls that "responding to apneas" as well. But I'm not so sure I agree with the pressurized-cork theory when we're talking about avoiding a comparatively quick 1 cm or 2 cm low-magnitude pressure increase.

The reason the discussion gets interesting for me at this point is because: 1) I don't think algorithmic or mechanical technology limitations ever prevented quicker pressure increases in response to detected apneas, 2) I don't think the cork blockage analogy truly factors in here (could be wrong), but 3) I genuinely think we're seeing that the APAP companies have always had to wrestle with that approximately 15% of the SDB population who have pressure-related homeostatic transition problems.

Bill, that Healthdyne patent description work that you interpreted and shared with us wasn't wasted work by any stretch of the imagination. Aside from doing an excellent job of interpreting it, you shared a very important and relevant piece of APAP history with us, IMHO.

You'll note the Healthdyne machine had the capabilites to both detect apneas and quickly increase pressures. But it always waited every apnea out instead, for lack of knowing when it was coping with an obstructive, central, or mixed apnea---and for fear of inducing successions of central apneas. The approximately 15% of the SDB population now suspected of having a complex response to static pressure variation has always been hiding in the human population. And the APAP manufacturers have always been forced to cope with those epidemiological realities by somehow minimizing or avoiding the homeostatic effects of pressure swings.

So what's one of the hottest topics up to bat in SDB medicine right now? That approximately 15% of the SDB population who exhibit complex homeostatic difficulties in relation to pressure changes. And which xPAP modality did Gilmartin, et al cite as being most problematic for those with complex sleep apnea? The research of Gilmartin, et al clearly cited APAP modality as being the most problematic modality for CSDB/CompSA.

That's only my opinion, guys. So please be kind or entertaining or both as you disagree with me! But I honestly don't think that typically cautious APAP pressure-response algorithms relate to pressurized-cork theory. Rather, I think the caution relates to pressure-related homeostatic issues that have always been present in a very significant portion of the SDB population. The patent descriptions thus all cite significant concerns about: 1) central apnea induction and 2) inadequate means of central apnea differentiation.

But I have yet to see a single patent description cite any concerns whatsoever about cork-style tongue blockages. .

-SWS wrote:But I have yet to see a single patent description cite any concerns whatsoever about cork-style tongue blockages.

That's a relief!

I sure didn't want to start digging into the patents myself -- not that I'd have understood them. I'd rather bake cookies. (And I don't even like to cook!)

I do like seeing you dig into the patents and discuss them, though.

SWS wrote:Rather, I think the caution relates to pressure-related homeostatic issues that have always been present in a very significant portion of the SDB population. The patent descriptions thus all cite significant concerns about: 1) central apnea induction and 2) inadequate means of central apnea differentiation.

Very good point.