ResScan UnderReporting or SmartLink OverReporting or ?

Insofar as what appears to be a more aggressive response by the S9, I notice that I am sensitive to fairly small increases in pressure. Likely it is because I try to keep my mask as loose as possible for a comfortable fit while still maintaining a good seal with minimal leaks. A 2 cmH2O increase definitely affects the sealing of the mask, and with leaks comes frequent 'arousals' to fix the mask and I do not sleep well. I seem to recall the DeVilbiss materials stating their algorithm makes no more than 1.0 cmH2O/minute increase in pressure, and no more than 0.1 cmH2O/minute decrease in pressure. I am not aware of the corresponding ResMed rate of change limitations - if any.

Referring to rate of change and its limits: read viewtopic.php?p=416814#p416814

It is a discussion of a study comparing the response of autoadjusting machines to various breathing patterns fed to them artificially http://www.sleepreviewmag.com/issues/ar ... -09_02.asp . Please, do read the study to the very end, and the whole thread.

When you look at the charts, you can see, the Respironics really zoom when encountering flow limitations.

ozij wrote:

Insofar as what appears to be a more aggressive response by the S9, I notice that I am sensitive to fairly small increases in pressure. Likely it is because I try to keep my mask as loose as possible for a comfortable fit while still maintaining a good seal with minimal leaks. A 2 cmH2O increase definitely affects the sealing of the mask, and with leaks comes frequent 'arousals' to fix the mask and I do not sleep well. I seem to recall the DeVilbiss materials stating their algorithm makes no more than 1.0 cmH2O/minute increase in pressure, and no more than 0.1 cmH2O/minute decrease in pressure. I am not aware of the corresponding ResMed rate of change limitations - if any.

Referring to rate of change and its limits: read viewtopic.php?p=416814#p416814

It is a discussion of a study comparing the response of autoadjusting machines to various breathing patterns fed to them artificially http://www.sleepreviewmag.com/issues/ar ... -09_02.asp . Please, do read the study to the very end, and the whole thread.

When you look at the charts, you can see, the Respironics really zoom when encountering flow limitations.

Thanks O.

I managed to find that article some time ago. I am pretty sure the link was sent to me by someone here, but I've forgotten who it was, hence, cannot give proper credit. Anyway, it was an interesting read. The thread, and the many links by RG, were also quite helpful.

Returning the 'favor', you might find this white paper from DeVilbiss interesting. They address many of the same points as those in the sleepreviewmag article, in fact, drawing on some of the same graphs I believe. Here is a link to the report -- http://www.mediafire.com/?f1965ks6mjkjm02.

Still, most of this particular discussion revolves around the auto-titration features whereas my immediate 'mission' is to eliminate, as much as I can anyway, those auto responses from the metrics by applying static pressures to generate the metrics as was suggested upthread.

It will take an additional few days till I have more data to report.

Concerning the ResMed chart:
I use an S8 - when I run it with EPR no equal to 0, I get two pressure lines in the chart, one called "therapy" and the other calle "average pressure". is that different on S9? I only see one pressure line -- .


Where is that medifire file from?

ozij wrote:Concerning the ResMed chart:
I use an S8 - when I run it with EPR no equal to 0, I get two pressure lines in the chart, one called "therapy" and the other calle "average pressure". is that different on S9? I only see one pressure line -- .


Where is that medifire file from?

O.,

Not sure about the S8, but I just looked closely at ResScan to see what is displayed, and what is available to be displayed (user selections), and I do not see anything called "therapy" to display. Maybe ResScan automatically includes that if/when the EPR is set to 0 ??

I am using ResScan 3.11 BTW.

In terms of the link to the file at Mediafire, I just chose Mediafire to upload and store the DeVilbiss report - so that it could be available to download. One of the criticisms I have of CPAPtalk is the inability to attach files to posts - which would make such things VASTLY more convenient for everyone.

The host for embedded graphics is much easier to use than Mediafire, but does not accept anything other than graphic image files.

Speaking of graphic files and comparisons - a while back I tried to use a pulse oximeter, the CMS50F. I had quite a bit of trouble getting it to work reliably and never felt I could trust the data. The best (as in - most complete) data I was able to capture is shown below - captured on 29Sep2010:



Because of strong suspicions that it was just not recording accurately, I decided to get an SPO7500, and tried it for the first time last night. Summary result below:



And accompanying S9 report:



The SPO7500 is a VAST improvement over the Contec, IMNSHO. It will take me some time to make my way through learning how to use the software to interpret and analyze the recorded data - but now I feel confident in the data being collected.

I hope the SPO collected data conforms to accepted standards [ducking and running for cover . . . ]

DHC wrote:

ozij wrote:Concerning the ResMed chart:
I use an S8 - when I run it with EPR no equal to 0, I get two pressure lines in the chart, one called "therapy" and the other calle "average pressure". is that different on S9? I only see one pressure line -- .


Where is that medifire file from?

O.,

Not sure about the S8, but I just looked closely at ResScan to see what is displayed, and what is available to be displayed (user selections), and I do not see anything called "therapy" to display. Maybe ResScan automatically includes that if/when the EPR is set to 0 ??

I am using ResScan 3.11 BTW.

When EPR is not equal to 0, i.e. when EPR is set on 1 or 2 or 3, ResScan 3.11 shows two pressure lines in the pressure chart.
The pressure chart you posted shows only one line.
Yet you say you the following:

DHC wrote:Both the DeVilbiss and the ResMed are using DEFAULT parameters for EPR and SmartFlex. Those are an EPR value of 2 for the ResMed - and an IRnd setting of 3 and ERnd setting of 3 for the DeVilbiss. All settings are at the midpoint within the range of available settings.

.

In terms of the link to the file at Mediafire, I just chose Mediafire to upload and store the DeVilbiss report - so that it could be available to download.

My question is about the source of that file. Where was it published?

ozij wrote:

DHC wrote:

ozij wrote:Concerning the ResMed chart:
I use an S8 - when I run it with EPR no equal to 0, I get two pressure lines in the chart, one called "therapy" and the other calle "average pressure". is that different on S9? I only see one pressure line -- .


Where is that medifire file from?

O.,

Not sure about the S8, but I just looked closely at ResScan to see what is displayed, and what is available to be displayed (user selections), and I do not see anything called "therapy" to display. Maybe ResScan automatically includes that if/when the EPR is set to 0 ??

I am using ResScan 3.11 BTW.

When EPR is not equal to 0, i.e. when EPR is set on 1 or 2 or 3, ResScan 3.11 shows two pressure lines in the pressure chart.
The pressure chart you posted shows only one line.
Yet you say you the following:

DHC wrote:Both the DeVilbiss and the ResMed are using DEFAULT parameters for EPR and SmartFlex. Those are an EPR value of 2 for the ResMed - and an IRnd setting of 3 and ERnd setting of 3 for the DeVilbiss. All settings are at the midpoint within the range of available settings.

.

In terms of the link to the file at Mediafire, I just chose Mediafire to upload and store the DeVilbiss report - so that it could be available to download.

My question is about the source of that file. Where was it published?

>>My question is about the source of that file. Where was it published?<<

Not sure. It came to me via email. Looks like it is probably a part of DeVilbiss clinical education program found at the link you provided to their excellent online webinars.

Re: The graphs. You seem to think there is a contradiction in what I wrote. Not so. Evidence the following:








I wrote that the EPR setting in the S9 is at 2 - and it is. I provided accurate screenshots taken from ResScan and posted those. There is only one line for pressure in the charts. I cannot explain why your graphs contain information that mine do not - but if you care to provide me instructions as to how to get ResScan to display what you wish to see - I am happy to do so.

- Dan

It's the default presentation on an S8.

An example from a post by DreamOn
viewtopic.php?p=435589#p435589

DreamOn wrote: Here's a screenshot of one of the ResScan screens:

.

Another update to the data previously reported - as follows:

The last reported information was for Oct 17/18. Since then . . .

Oct 18/19 - AHI 0.5 (S9) using fixed CPAP 9.0 w/EPR 2
Oct 19/20 - AHI 0.1 (S9) using fixed CPAP 9.0 w/EPR 2
Oct 20/21 - AHI 0.1 (S9) using fixed CPAP 7.0 w/EPR 2

Oct 21/22 - AHI 5.3 (IP) using fixed CPAP 7.0 w/SmartFlex ON
Oct 22/23 - AHI 3.2 (IP) using fixed CPAP 7.0 w/SmartFlex ON
Oct 23/24 - AHI 1.1 (IP) using fixed CPAP 7.0 w/SmartFlex OFF
Oct 24/25 - AHI 2.9 (IP) using fixed CPAP 7.0 w/SmartFlex OFF

Oct 25/26 - AHI 1.1 (S9) using fixed CPAP 7.0 w/EPR 2

I now need to run the S9 with EPR set to 'OFF' to remove that from the results and see if there is any difference.

The other bit of information I now have is SPO2 results from the SPO 7500 that I can believe. That shows the following O2 DeSaturation Index:

Oct 19/20 - 4.4
Oct 20/21 - NA
Oct 21/22 - 3.2
Oct 22/23 - 2.0
Oct 23/24 - 3.5
Oct 24/25 - 4.7
Oct 25/26 - 7.4

A few observations:

The IntelliPAP was not at all difficult to breathe against (exhale) with SmartFlex turned to OFF. I recall the reports of people who used the IntelliPAP before SmartFlex was incorporated and they too seemed to have very little trouble without SmartFlex. Since both EPR and SmartFlex are primarily comfort aids, I did not expect them to have much, if any, impact on the results - and that seems to be the case with the IntelliPAP. I have yet to use the S9 with EPR turned off - but will report those results when gathered.

The other thing I noted is that the SPO2 results from Oct 21 - 25 were gathered while on a trip to a city at about sea level. I normally live at about 6000 feet of elevation, and it seems to result in the O2 levels being slightly lower when I am at the higher elevation with a greater number of desaturations.

I continue to feel the S9 is under-reporting AHI. Looking at the reports from Oct 19/20 and 20/21 - as ozij stated upthread, one would expect the AHI to increase with a reduction in pressure - yet, there was no change in reported AHI with the S9 when the pressure was reduced from 9.0 cmH2O to 7.0 cmH2O.

Offered FWIW

My comment;
would that on when you change pressure on
Oct 20/21 - AHI 0.1 (S9) using fixed CPAP 7.0 w/EPR 2
that shows no change but that is only one night and my experience with auto CPAP is that it takes about
three days for my airway to lose the "physical splint memory" with a one cm water decrease in pressure before the
full effects are known. I get similar results on three different auto CPAP's that I have been using over the years.

Second, you later show on;
Oct 25/26 - AHI 1.1 (S9) using fixed CPAP 7.0 w/EPR 2
This shows a higher AHI with the Resmed and since this is just two
different nights I say it is a bit inconclusive but it may show that
the AHI is slowly increasing after a few days at the lower 1cm of pressure.
We would need more data to see if this is the case or not.

john5757 wrote:My comment;
would that on when you change pressure on
Oct 20/21 - AHI 0.1 (S9) using fixed CPAP 7.0 w/EPR 2
that shows no change but that is only one night and my experience with auto CPAP is that it takes about
three days for my airway to lose the "physical splint memory" with a one cm water decrease in pressure before the
full effects are known. I get similar results on three different auto CPAP's that I have been using over the years.

Second, you later show on;
Oct 25/26 - AHI 1.1 (S9) using fixed CPAP 7.0 w/EPR 2
This shows a higher AHI with the Resmed and since this is just two
different nights I say it is a bit inconclusive but it may show that
the AHI is slowly increasing after a few days at the lower 1cm of pressure.
We would need more data to see if this is the case or not.

Thanks for the comments.

BTW - when I am reporting Oct 25/26, I mean it to be the report that normally starts on the evening of Oct 25 and concludes the morning of Oct 26, so it is only one night. Just wanting to be sure the data is interpreted correctly.

I agree there are not many datapoints as yet, hence, very little that might be considered conclusive just yet - and maybe not ever.

The AHI on Oct 25/26 with the S9 is the only datapoint in which the AHI reported by ResMed even approaches 1.0 - in this one instance crossing it at 1.1. I will be using the S9 again tonight only without EPR, so the results of the next couple of days should prove helpful to determine if this was anomalous or not.

I have read and reread much of the information in this thread. It's clear that there are many knowledgeable folks on this forum.

Suppose one were to focus on the first half of the title. Specifically, is ResScan (i.e. S9) Under Reporting? Wouldn't the answer be determined by first knowing what is being measured by the device, and secondly by whether or not the device is making the proper measurements as claimed.

A reference to "what is being measured part" seems to be included in the Data Management Guide.

http://www.cpapmachinesandsupplies.com/ ... nglish.pdf

Excerpts from this document:

Apnea - An apnea is the temporary absence or cessation of breathing. An apnea is scored when there is a reduction in breathing by 75% of the baseline breathing for at least 10 seconds.

Hypopnea - A hypopnea is an episode of shallow breathing during sleep. A hypopnea is scored when there is a reduction in breathing by 50% of baseline breathing with partial upper airway obstruction for 10 seconds or more. The event is scored after 10 seconds of the hypopnea.

Events - An event is the occurrence of a residual apnea or hypopnea.

AHI - The total number of events calculated by adding apnea and hypopnea divided by daily usage.

Daily Usage - Total usage from mid day to mid day.

So the next question is how well does the S9 do what it claims to do above? If it accurately measures what it claims to measure, isn't that what's most important? I searched for a ResMed white paper document that would speak to device accuracy w/r AHI. All I could find is the reference below on accuracy w/r detecting central apneas.

http://www.resmed.com/us/assets/documen ... -paper.pdf

Surely, somewhere there is another ResMed study on accuracy w/r detecting ALL apneas as defined within their above Data Management Guide.

Ideally, it would be great if all devices align closely with results in a PSG study. Perhaps, as noted by the many posters above, this ideal will never be met. Nonetheless, I'd bet that the machine manufacturers would like to be close.

But back to the title of DMC's thread. "ResScan Under Reporting or Smartlink Over Reporting or ?". It's a great question. But IMO, its a question that is difficult to answer...

1) Each machine has a different target, i.e. what the machine is measuring.

2) Each machine has a different measurement error when measuring it's respective target.

3) Each machine has different operating characteristics that will influence the patient's AHI being targeted for measurement. (Note: Using a constant pressure was an attempt to lessen this source of variability.)

4) Other? (Did I skip any other sources of variability?)

So I guess I continue to be of the opinion that the "or ?" is my "current" answer to the question of this thread. It's my answer until we get a bit more data.

XSnorer wrote:I have read and reread much of the information in this thread. It's clear that there are many knowledgeable folks on this forum.

Suppose one were to focus on the first half of the title. Specifically, is ResScan (i.e. S9) Under Reporting? Wouldn't the answer be determined by first knowing what is being measured by the device, and secondly by whether or not the device is making the proper measurements as claimed.

A reference to "what is being measured part" seems to be included in the Data Management Guide.

http://www.cpapmachinesandsupplies.com/ ... nglish.pdf

Excerpts from this document:

Apnea - An apnea is the temporary absence or cessation of breathing. An apnea is scored when there is a reduction in breathing by 75% of the baseline breathing for at least 10 seconds.

Hypopnea - A hypopnea is an episode of shallow breathing during sleep. A hypopnea is scored when there is a reduction in breathing by 50% of baseline breathing with partial upper airway obstruction for 10 seconds or more. The event is scored after 10 seconds of the hypopnea.

Events - An event is the occurrence of a residual apnea or hypopnea.

AHI - The total number of events calculated by adding apnea and hypopnea divided by daily usage.

Daily Usage - Total usage from mid day to mid day.

So the next question is how well does the S9 do what it claims to do above? If it accurately measures what it claims to measure, isn't that what's most important? I searched for a ResMed white paper document that would speak to device accuracy w/r AHI. All I could find is the reference below on accuracy w/r detecting central apneas.

http://www.resmed.com/us/assets/documen ... -paper.pdf

Surely, somewhere there is another ResMed study on accuracy w/r detecting ALL apneas as defined within their above Data Management Guide.

Ideally, it would be great if all devices align closely with results in a PSG study. Perhaps, as noted by the many posters above, this ideal will never be met. Nonetheless, I'd bet that the machine manufacturers would like to be close.

But back to the title of DMC's thread. "ResScan Under Reporting or Smartlink Over Reporting or ?". It's a great question. But IMO, its a question that is difficult to answer...

1) Each machine has a different target, i.e. what the machine is measuring.

2) Each machine has a different measurement error when measuring it's respective target.

3) Each machine has different operating characteristics that will influence the patient's AHI being targeted for measurement. (Note: Using a constant pressure was an attempt to lessen this source of variability.)

4) Other? (Did I skip any other sources of variability?)

So I guess I continue to be of the opinion that the "or ?" is my "current" answer to the question of this thread. It's my answer until we get a bit more data.

Thanks for your comments. The comments are timely as I have some more data to report - as follows:

Oct 26/27 - AHI 0.4 (S9) using fixed CPAP 7.0 w/EPR OFF
Oct 27/28 - AHI 0.3 (S9) using fixed CPAP 7.0 w/EPR OFF

I missed a step in the process for SPO2 collection (forgot to erase the 'study' after downloading data) one day, so missed the O2 DeSat Index for Oct 26/27 - but for Oct 27/28 the ODI was 16.0.

So with the data being displayed in posts upthread, here are the AHI summaries of the data:

15 nights of data collected for the S9
14 nights of data collected for the IntelliPAP

Overall Average AHI:
IntelliPAP - 3.28
S9 - 0.38

Average AHI with Auto:
IntelliPAP - 3.38
S9 - 0.36

Average AHI w/ Fixed CPAP
IntelliPAP - 3.16
S9 - 0.40

Average AHI w/o SmartFlex/EPR
IntelliPAP - 2.00
S9 - 0.35

Except for the unexpected drop in AHI reported by the IntelliPAP with SmartFlex turned OFF, all other results look reasonably consistent - and disparate from one machine to the other.


Average O2 DeSat Index ODI (*CAUTION* - needs more data to establish reliability):

IntelliPAP - 3.4
S9 - 9.3

Notably, there are only 3 data points collected for the S9 and 4 for the IntelliPAP. Further, the IntelliPAP results were collected while traveling to a near sea level location, whereas my home is nearly 6000 feet in elevation - likely accounting for significant differences in O2 levels.

As I understand the O2 DeSaturation Index (ODI), it is a calculation based upon the number of O2 desaturation events that occur over a period of time. A desaturation event occurs when the oxygen level drops by at least 4 % for a minimum of 10 seconds. I further understand ODI to be 'graded' according to this scale:

< 5 = Normal
5 - 15 = Mild
16 - 29 = Moderate
> 30 = Severe

Part (much?) of my reason for looking at the ODI is that it *may* provide a useful indicator *in combination with* reported results from the machines to draw more informed conclusions.

I think there is little doubt that ResMed's S9 AutoSet reports AHI on a much different basis than DeVilbiss' IntelliPAP AutoAdjust. Does this matter? Perhaps not if one is looking at the data only for trends and to 'tweak' their machines to provide maximum therapeutic benefit. Many (or most?) of us fall into this category, hence, the issue of absolute accuracy reported to a fixed standard is NOT terribly significant.

>>So I guess I continue to be of the opinion that the "or ?" is my "current" answer to the question of this thread. It's my answer until we get a bit more data.<<

Is there some other data I might provide/collect that you think will help to advance our understanding of this question?

DHC wrote: .................................
Average O2 DeSat Index ODI (*CAUTION* - needs more data to establish reliability):

IntelliPAP - 3.4
S9 - 9.3

Notably, there are only 3 data points collected for the S9 and 4 for the IntelliPAP. Further, the IntelliPAP results were collected while traveling to a near sea level location, whereas my home is nearly 6000 feet in elevation - likely accounting for significant differences in O2 levels.

As I understand the O2 DeSaturation Index (ODI), it is a calculation based upon the number of O2 desaturation events that occur over a period of time. A desaturation event occurs when the oxygen level drops by at least 4 % for a minimum of 10 seconds. I further understand ODI to be 'graded' according to this scale:

< 5 = Normal
5 - 15 = Mild
16 - 29 = Moderate
> 30 = Severe

Part (much?) of my reason for looking at the ODI is that it *may* provide a useful indicator *in combination with* reported results from the machines to draw more informed conclusions.
...................................
Is there some other data I might provide/collect that you think will help to advance our understanding of this question?

Good question. I'm not sure how any of us without the proper equipment could setup a controlled experiment to determine if the S9 or IntelliPAP reports accurately or not. So it would be nice to see a study that ResMed or Devilbiss has already done in this regard.

But, maybe your above thoughts & comments on the ODI are more relevant. This seems to be key. Controlling AHI correlates with controlling ODI. So one could modify the hypotheses to:

H0: S9 and IntelliPap are equivalent in controlling ODI
vs
Ha: ResMed and IntelliPap are not equivalent.

The "experiment" would then run alternate days with each machine operating unconstrained while recording SPO2. Multiple data points could be collected. The different operating characteristics of the machines become part of the experiment. Each machines mesurement error on AHI is irrelevant. The focus becomses SPO2. Hopefully the same device can be used to measure SPO2. Using one SPO2 device would eliminate a source of variation caused by having 2 devices.

Just thinking out loud. Perhaps others following this thread may have additional thoughts...

I for one want to thank DHC for all his hard work. I am looking to buy one of these two machines, with my own money, come the first of the year. I primarily want a new machine so I can track my sleep and see what improvements I can make. While I realize that the AHI from these machines is going to be relative but what kind of trends are you going to get if the numbers are all below 1.0 and you have to supply some kind of error bars on the data. All so How is a person going to evaluate weather or not a specific machine reduces their particular apneas compared to a different machine. For people like me, who have seasonal allergies it could take several weeks to be able to tell if my treatment is working correctly, if I couldn't be able to have compare to instead of something like "feelings" that is so subjective.

Bob

physicsbob wrote:I for one want to thank DHC for all his hard work. I am looking to buy one of these two machines, with my own money, come the first of the year. I primarily want a new machine so I can track my sleep and see what improvements I can make. While I realize that the AHI from these machines is going to be relative but what kind of trends are you going to get if the numbers are all below 1.0 and you have to supply some kind of error bars on the data. All so How is a person going to evaluate weather or not a specific machine reduces their particular apneas compared to a different machine. For people like me, who have seasonal allergies it could take several weeks to be able to tell if my treatment is working correctly, if I couldn't be able to have compare to instead of something like "feelings" that is so subjective.

Bob

I am pleased that others are finding the exercise of some value. I have about another week to continue with the data collection until I have another surgery that will derail things for a time, and will continue to report on what I find till then.

Insofar as a choice between the IntelliPAP and the S9, it may be a bit of a 'cop-out' but I think both machines will provide effective xPAP treatment. There are things I like about each one. In my case I did not have to pay for the S9, though I *did* pay for the IntelliPAP. If I were required to spring for the cost of the S9, I am not sure I could justify the higher price.

XSnorer wrote:I'm not sure how any of us without the proper equipment could setup a controlled experiment to determine if the S9 or IntelliPAP reports accurately or not. So it would be nice to see a study that ResMed or Devilbiss has already done in this regard.

But, maybe your above thoughts & comments on the ODI are more relevant. This seems to be key. Controlling AHI correlates with controlling ODI. So one could modify the hypotheses to:

H0: S9 and IntelliPap are equivalent in controlling ODI
vs
Ha: ResMed and IntelliPap are not equivalent.

The "experiment" would then run alternate days with each machine operating unconstrained while recording SPO2. Multiple data points could be collected. The different operating characteristics of the machines become part of the experiment. Each machines mesurement error on AHI is irrelevant. The focus becomses SPO2. Hopefully the same device can be used to measure SPO2. Using one SPO2 device would eliminate a source of variation caused by having 2 devices.

Just thinking out loud. Perhaps others following this thread may have additional thoughts...

>>The "experiment" would then run alternate days with each machine operating unconstrained while recording SPO2. Multiple data points could be collected. The different operating characteristics of the machines become part of the experiment. Each machines mesurement error on AHI is irrelevant. The focus becomses SPO2.<<

I will do exactly as you describe for the next week. After that, my data collection will be interrupted by another surgery.

>> Hopefully the same device can be used to measure SPO2. Using one SPO2 device would eliminate a source of variation caused by having 2 devices.<<

Yes, I am using an SPO 7500 recording pulse oximeter worn on the wrist. I can use this independent of the xPAP device, and the SPO 7500 does seem to be reliable in its consistency of recording.

Thanks for the suggestion. Will report back once I have some more data to offer.