Discussion on Resmed Autoset Patents

After some discussion in another thread I have done some research on Resmed's patents.

Wulfman kindly supplied me with a link to one patent but that turned out to be for a machine never released by Resmed & called the Auotoset Plus. It used a probing technique based on FOT - Forced Oscillation Technique). SWS has pointed out (and clearly knows this issue well) that most companies who tried FOT have either never released commercial products using it, or in the case of Weinmann, appear to have dropped it from their product lines).

I then listed all the US patents applying to the S8 Autoset II as listed in the Clinical manual for the s8 Autoset II.

Then starting with the 1st one am working my way through them. The 1st Patent listed for an Autoset algorithm and filed by Berthon-Jones (Resmed designer) is 5704345. The date of filing being Nov 04 1994. The title being =
"Detection of apnea and obstruction of the airway in the respiratory system"

In this patent they say the following which seems to me that Resmed were always using a technique to look for cardiac oscillations to help determine if an APNEA was obstructive or central.

I guess my question here & hopefully SWS may know, is does Resmed do the below in the S8 Autoset or is it patent data that was filed but not used & If it isn't used how would we know it isn't ?

I am still working my way through the entire list (20 odd patents) but this early description suggests they were always looking for "presence of cardiogenic air flow" way back in the early 1990s ?

DSM

#2 Just also came across the 1st patent for the A10 algorithm = 6367474 Dated Jan 19 1998

**********************************************************************************

5704345 Is described as the original Autoset patent (this came from the following statement in patent 6029665) ...
"More sophisticated forms of CPAP, such as bi-level CPAP and autosetting CPAP, are described in U.S. Pat. Nos. 5,148,802 and 5,245,995 respectively. "

(a) an apnea is occurring, determined by the steps of: measuring respiratory air flow from the patient as a function of time; and determining the variance of said measured air flow as an indication of an apnea occurring;
or
(b) there is partial obstruction of the airway, determined by the steps of:
measuring respiratory air flow from the patient:
detecting the inspiratory part of said air flow:
normalising said inspiratory part; and
determining an index value of a mid-portion of said normalised inspiratory part as a measure of partial obstruction.
or
(c) there is patency of the airway, determined by the steps of:
(i) applying an oscillatory pressure waveform of known frequency to the patient's airway;
measuring respiratory air flow from the patient; and
determining that the airway is patent if there is a component of said air flow at said known frequency induced by said oscillatory pressure waveform:
or
(ii) measuring respiratory air flow from the patient; and
analysing said measured air flow to detect the presence of cardiogenic air flow, and if so then the airway is declared patent.
The invention vet further discloses apparatus for determining the occurrence of an apnea in a patient, the apparatus comprising:
means for measuring respiratory air flow from the patient as a function of time;
means for determining the variance of said measured air flow, and
means for determining from said variance that an apnea is occurring.

****************************************************************************

#3 Corrected ref from 'S8 Autoset II Plus' to 'Autoset II Plus'

dsm wrote:.......that turned out to be for a machine never released by Resmed & called the S8 Auotoset Plus.

You sure about that? Maybe they released it as the S8 Autoset II.

I have no idea. I even missed the word "Plus" in there, but I was hurriedly scanning it for the functions and the 10 cm. limitation. Maybe they decided against using the word "Plus" because Respironics was already using it with a non-data-capable machine.

There's got to be a "conspiracy theory" here somewhere......

Den

Wulfman,

SWS provided this link that identified the Autoset II Plus that was covered by that patent you kindly supplied ...

http://scholar.google.com/scholar?q=%22 ... tnG=Search

Cheers

DSM

#2 The refs to that model go way back to 2002/2003. Resmed applied for their 1st FOT patent back in the mid 1990s - as SWS said, the technique has been quietly dropped by even Weinmann who used to have it in their SOMNOsmart 2 Auto cpap machine but no longer mention it in their literature.

Now this is getting confusing. The patent numbered 6367474 refers to a FOT technique using a 4HZ burst. That is what the patent
adds.

This patent is listed as being part of the S8 Autoset II ! - so that seems to agree that FOT is indeed used in the S8 Autoset II, else why
list the patent for it as part of the S8 Autoset II product.

So there is a 'little mystery' here. Has FOT been dropped by Resmed after their trials with the Autsoet II Plus back in 2002/2003 or have Resmed now reintroduced FOT into the new S8 Autoset II ?

I believe FOT was leak intolerant. Maybe with the newer improved masks they have brought it back. Also that gets back to is FOT in the Vpap Adapt SV. It could well be.

DSM

Well, the interesting thing about that part of the patent, Doug, is that it's not a new Resmed "embodiment" exactly as you said. These are seven Resmed patent descriptions beyween the years 1994 and 2004 that use that same phraseology to describe their patented version of FOT:
Google Patent Search Yielding identical 1994 through 2004 Search Text in Resmed Patent Descriptions

So it's not a new thing Resmed put in their patent description just before their latest AutoSet model came out. But in these Resmed patent descriptions, you can see they claim FOT has some serious shortcomings:
FOT for Naught According to These Expressed Resmed Opinions

above Resmed patent descriptions each wrote:This ‘forced oscillation method’ requires the ability to modulate the mask pressure at 4 Hz, which increases the cost of the device. Furthermore, the method does not work in the presence of high leak, and can falsely report that the airway is closed if the subject has a high nasal or intrapulmonary resistance.

In short, none of us have ever been able to find Resmed's implementation of FOT in any model except the experimental AutoSet II Plus (and thanks to ozij for finding that a while back). I would also speculate that the word "Plus" in that model name refers to the additional embodiment of Resmed's FOT. I would additionally speculate that Resmed would have updated their 2008 Clinician manual to include FOT exactly as they updated their 2008 text to describe their updated version of expiratory pressure relief.

I honestly don't think there's a solid hint that FOT technology has finally been employed in Resmed's latest mass-produced AutoSet, Doug. At least I can't find the slightest hint yet.

dsm wrote:so that seems to agree that FOT is indeed used in the S8 Autoset II, else why list the patent for it as part of the S8 Autoset II product.

Even a tiny aspect of the novelty embodied in an earlier patent that is relied up on by a later patent by the same applicant will generally cause the prior work patent to be shown in the later patent.

So there is no automatic grounds for assuming that FOT as a complete technology approach is the novelty from the earlier patent which has been incorporated in the later patent. It could be something quite minor

Cheers,

Bill

Also there is never a one-to-one correlation between all embodiments in a Resmed patent description and all embodiments in a Resmed manufactured product.

Any one Resmed patent description can have a combination of: 1) embodiments that were never manufactured or mass-produced, 2) embodiments in a single product, and/or 3) embodiments employed in multiple products. Additionally, any one Resmed product will always draw embodiments from several patent descriptions.

So it really doesn't make sense to view any Resmed patent description as if it were the equivalent of a comprehensive design document for a single product. Patents are essentially legal protection----they are never cohesive design documents in Resmed's case.

SWS Bill,

Makes sense.

I did just find this in a Berthon-Jones patent # 6988498 dated Oct 05 2004

"Some open airway apneas can occur at low pressure. By combining the forced oscillation method with the present invention, with the additional requirement that there be no increase in pressure if the forced oscillation method detects an open airway, false increases in pressure in response to open airway apneas at low pressure will be largely avoided."

That seemed fairly strong wording & did make me wonder. This patent was granted in Jan 24 2006 well after the Plus trials.

But all in all the points being made that despite these patents being listed for the S8 Autoset II, they don't mention it in the manuals.

Still have about 4 more to work through.

DSM

Corrected granting date to 2006

billbolton wrote:It could be something quite minor

Agreed. The other tricky yet supposedly legal thing about patent listings is when the word "may" is used preceding a list of patent numbers. That means some of the patents may not even have contributing embodiments.

That legal loophole allows the product to be updated, by the way of changing/adding/dropping which embodiments happen to be implemented at any given point in production. But it also conveniently serves as the equivalent of "Three Shell" guessing game to throw off competitors----with plenty more than three mystery shells/patent-numbers in the guessing mix.

But I think if Resmed honestly thought that FOT was a superior technology---then they would showcase that FOT technology somewhere in their explanatory text, rather than describe A10 as they currently do. I don't think Resmed views FOT as worthwhile based on described shortcomings.

Here is a list of all the patents plus when filed & under whose name plus the summary line & I have added some points related to the details therein.

It gives us the info on what may have gone into the S8 Autoset II.

http://www.internetage.ws/cpapdata/pate ... atents.txt
Happy reading

I guess the real issue is that no matter what is read, there is no certainty that the inventions described, even in the most recent patent that applies to the S8 Autoset II, is necessarily used.

The only thing I know for certain is that the quality of the sensors and the quietness of the blowers, the size of the machines & the effectiveness of the masks has improved markedly in the past 10 years.

DSM

-SWS wrote:Also there is never a one-to-one correlation between all embodiments in a Resmed patent description and all embodiments in a Resmed manufactured product.

Any one Resmed patent description can have a combination of: 1) embodiments that were never manufactured or mass-produced, 2) embodiments in a single product, and/or 3) embodiments employed in multiple products. Additionally, any one Resmed product will always draw embodiments from several patent descriptions.

So it really doesn't make sense to view any Resmed patent description as if it were the equivalent of a comprehensive design document for a single product. Patents are essentially legal protection----they are never cohesive design documents in Resmed's case.

Wording that has shown up that I take to mean is a used feature is when they say 'the preferred embodiment yadda yadda yadda' & describe a feature.

That last FOT reference was new wording in that late 2004 application (granted in 2006). I know it doesn't prove anything but why resubmit a new patent that is essentially similar to prior ones but adds different words for FOT & do this 2-3 years after trialling an earlier machine that tried a variant of FOT but never went to market. So whilst I agree that if they had included FOT why wouldn't they say so, but then, if Weinmann was able to use FOT was it a sub license off a Resmed patent or can any one add FOT & if anyone can then perhaps the vendor who chooses to use it may want to say nothing.

It is in the back of my mind how much effort Resmed recently put into redesigning their masks. I know the Vpap Adapt SV would not work with many masks when it came out BUT interestingly, when the 1st Autoset-T came out in 1999/2000 there was only 1 mask they would recommend that worked with it. By 2001/2 that had changed & they were recommending a wider range - plus they dropped use of the proximal sensing line by providing an attachment that ended the proximal sensing line at the air exit.

The patent numbered 6138675 also provides insights into why Resmed 1st used one. I recall a debate we had here some many months back where SAG SWS & I were discussing why it was there. IIRC SAG voted for it being to sense mask presence & leaks. SWS voted for it being used to take the many sample points the Vpap Adapt SV uses to monitor one breath. I also believed it was for the sampling but in particular because of the speed the machine ramps up its pressure, it could only reliably do so by sampling pressure at the mask while it did so. In hindsight I thing all three points were probably valid.

DSM

dsm wrote:I recall a debate we had here some many months back where SAG SWS & I were discussing why it was there. IIRC SAG voted for it being to sense mask presence & leaks. SWS voted for it being used to take the many sample points the Vpap Adapt SV uses to monitor one breath. I also believed it was for the sampling but in particular because of the speed the machine ramps up its pressure, it could only reliably do so by sampling pressure at the mask while it did so. In hindsight I thing all three points were probably valid.

Think that was us trying to figure out what Resmed's most compelling incentive might have been for using a proximal sensor line. My final conclusion was that there were multiple good reasons as well.

But speaking of FOT, did you take a look yet at the diagrams in that II Plus bench study I mentioned earlier? You can see the bottom line---the pulse oscillation carrier wave----reflect/fluctuate according to the various SDB events versus normal low-impedance breathing.