ResScan UnderReporting or SmartLink OverReporting or ?

[DHC]

As indicated earlier, I am continuing with the collection of data from the ResMed S9 AutoSet and the DeVilbiss IntelliPAP AutoAdjust - now combining that with collection of ODI (Oxygen DeSaturation Index) from the SPO 7500.

I changed the settings on both APAP machines to the following:

Automatic Mode (from fixed CPAP)
Lower Limit 6.0 cmH2O
Upper Limit 10.0 cmH2O
Ramp for 10 minutes starting at 4.0 cmH2O
Relief (EPR/SmartFlex) ON

Results as follows:

Oct 28/29 (S9) - AHI 0.4, ODI 10.0, 95th Percentile 8.7cmH2O
Oct 29/30 (IP) - AHI 1.6, ODI 15.0, 95th Percentile 6.0cmH2O

Here are the graphs:

Oct 28/29 (S9):


And for Oct 29/30 (IP):



One of the things that is becoming clearer to me is that the DeVilbiss algorithm intentionally seeks the lowest possible pressure, and its increases and decreases in pressure are gradual so as to not cause an arousal from the pressure changes. I am growing to appreciate those aspects of the DeVilbiss algorithm very much.

I am also finding more 'meaning' in the AHI reported by DeVilbiss. Though the DeVilbiss AHI recorded 1.6 last night *seems* to indicate more events than the S9 reported AHI from the night earlier, it was nearly the lowest AHI ever recorded by the IntelliPAP - and for a change, I do *feel* my sleep was improved.

Offered FWIW

[XSnorer]

DHC.... just curious.... have you had a chance to collect any more data?

[DHC]

DHC.... just curious.... have you had a chance to collect any more data?

Following sinus surgery on 11/5 I was told to not use CPAP for 30 days, though the surgeon modified that to allow use at a low (very low) pressure after the first visit at 7 days post-op. Since then I have been collecting data, though at this low pressure of 4.0 cmH2O to 5.0 cmH20 (max setting), hence, I am not sure the data is representative. The SPO2 readings are similarly anomalous as the sinuses are inflamed from the surgery and need a few weeks to settle down.

I saw a sleep doc the other day (for the first time) and we settled on a new range of pressures to use - now using min 7.0 cmH20 and max 12.0 cmH20, and continue to record data.

Will post the results of all this soon. Some of it is . . . odd, in that my AHI from both the S9 and the IntelliPAP did not show any significant change at the low pressure range as compared to the higher pressure range used prior to the sinus surgery and now again, as one might expect.

[Emilia]

I've read this thread off and on since it started, and it has been fascinating to see the work you have compiled. I've been using my DeVilbiss IP Auto w/Smartflex since Sept. 1 and have had a consistent average AHI of 1.6 each month. My lowest recorded AHI was a 0.3 and I've had a few others below 1, but most days I am in the 1.5-2.5 range. Looking at your comparisons, I suspect that if I owned an S9, I'd be having consistent AHI's of 0!

I had had an extremely easy time with this therapy, and I've loved using my IP.... I sleep like a baby with it. I also had great beginner's luck with the two masks I've used....hardly a leak at all.

Keep up the great research... it benefits us all. I suspect DeVilbiss has been reading this, too, with interest!

[DHC]

Looks like the last data I reported was for October 29/30. Here is the data collected since that date, inclusive of some commentary:

Oct 30/31 (IP): AHI 1.9, ODI 13.3, 95th Percentile Pressure 6.5 cmH20
Oct 31/Nov 01 (S9): AHI 0.6, ODI 9.8, 95th Percentile Pressure 9.2 cmH20
Nov 01/02 (S9): AHI 0.1, ODI 10.3, 95th Percentile Pressure 9.3 cmH20
Nov 02/03 (S9): AHI 0.2, ODI 8.2, 95th Percentile Pressure 8.9 cmH20
Nov 03/04 (S9): AHI 0.6, ODI 16.7, 95th Percentile Pressure 8.8 cmH20
Nov 04/05 (S9): AHI 0.0, ODI 14.4, 95th Percentile Pressure 8.9 cmH20
Nov 05/06 (No CPAP): ODI 17.0
Nov 06/07 (No CPAP)
Nov 07/08 (No CPAP)
Nov 08/09 (No CPAP)
Nov 09/10 (No CPAP)
Nov 10/11 (No CPAP)
Nov 11/12 (No CPAP): ODI 14.5
Nov 12/13 (No CPAP): ODI 22.4
Nov 13/14 (No CPAP)
Nov 14/15 (No CPAP)
Nov 15/16 (IP): AHI 2.0, 95th Percentile Pressure 4.5 cmH20
Nov 16/17 (IP): AHI 3.5, 95th Percentile Pressure 5.0 cmH20
Nov 17/18 (IP): AHI 2.4, 95th Percentile Pressure 4.5 cmH20
Nov 18/19 (IP): AHI 1.1, 95th Percentile Pressure 4.0 cmH20
Nov 19/20 (S9): AHI 1.1, 95th Percentile Pressure 4.9 cmH20
Nov 20/21 (S9): AHI 0.2, ODI 18.1, 95th Percentile Pressure 4.9 cmH20
Nov 21/22 (IP): AHI 1.6, 95th Percentile Pressure 4.0 cmH20
Nov 22/23 (IP): AHI 0.0, 95th Percentile Pressure 4.0 cmH20
Nov 23/24 (S9): AHI 0.2, 95th Percentile Pressure 4.9 cmH20
Nov 24/25 (S9): AHI 0.3, 95th Percentile Pressure 4.9 cmH20
Nov 25/26 (S9): AHI 0.2, 95th Percentile Pressure 5.0 cmH20
Nov 26/27 (S9): AHI 0.5, 95th Percentile Pressure 4.9 cmH20
Nov 27/28 (S9): AHI 0.9, 95th Percentile Pressure 5.0 cmH20
Nov 28/29 (S9): AHI 0.1, 95th Percentile Pressure 5.0 cmH20
Nov 29/30 (S9): AHI 0.7, ODI 15.6, 95th Percentile Pressure 5.0 cmH20
Nov 30/Dec 01 (S9): AHI 0.2, 95th Percentile Pressure 9.1 cmH20
Dec 01/02 (S9): AHI 0.6, ODI 15.3, 95th Percentile Pressure 8.0 cmH20
Dec 02/03 (S9): AHI 0.5, 95th Percentile Pressure 8.9 cmH20
Dec 03/04 (S9): AHI 0.4, 95th Percentile Pressure 7.2 cmH20
Dec 04/05(S9): AHI 0.4, 95th Percentile Pressure 10.7 cmH20
Dec 05/06 (IP): AHI 1.9, 95th Percentile Pressure 7.0 cmH20

To begin to make sense of the data, the following:

* Had major sinus surgery on 11/5, and ordered to NOT use CPAP for 30 days. Surgeon later allowed CPAP use at minimum pressures beginning on 11/15.
* There were a few days when I recorded the pulse/ox values without using CPAP just as an experiment.
* Pressures on 11/15 through 11/30 were low value of 4.0 cmH2O and high value of 5.0 cmH20.
* Beginning on 11/30 and based on meeting with a sleep doc, new pressure settings are low value of 7.0 cmH20 and max value of 12.0 cmH20.
* The sinuses are still inflamed from the surgery and will take some time to settle down completely, hence, some measurements may be anomalous.

Based on the data collected so far, I have the following impressions:

* ODI seems to be a pretty unreliable metric. It seems to have no correlation to the AHI metrics, nor to the subjective measure of how I 'feel.' I have been less rigorous than I should have been in collecting the pulse/ox metrics, and will be more conscientious going forward as I continue to look for a 'connection' of some sort.
* AHI continues to be reported as much higher with the IntelliPAP system.
* The S9 is more 'aggressive' at making adjustments to pressure, and invariably reports a considerably higher 95th Percentile Pressure than the IntelliPAP.
* The IntelliPAP is much more gradual with pressure changes.

Illustrating these last points are these charts - first the Pressure and Events from the S9 for 12/5:



And here is the same information using the IntelliPAP for the next day, 12/6:




The differences in the pressure changes is obvious. I find I am at least somewhat sensitive to changes in pressure, and that night with the S9 I slept very poorly.

At this point, I will review the topic for where it left off prior to the surgery and see what settings may be useful for gaining a better understanding of the efficacy of these devices.

Any suggestions and/or comments are welcomed.

[billbolton]

I find I am at least somewhat sensitive to changes in pressure

You should probably be using CPAP mode then.[/quote]

Cheers,

Bill

[DHC]

I find I am at least somewhat sensitive to changes in pressure

You should probably be using CPAP mode then.

Cheers,

Bill

Well, that is one possible conclusion.

Thanks for the input.

[DHC]

I find I am at least somewhat sensitive to changes in pressure

You should probably be using CPAP mode then.

Cheers,

Bill

Bill,

A nagging question keeps coming back to me, and I wonder if you would be willing to address it.

Do you have any interest, of any kind, to ResMed - other than as a patient using products they manufacture?

I look forward to your response (as always).

[billbolton]

Do you have any interest, of any kind, to ResMed - other than as a patient using products they manufacture?

As I've said before on a number of occasions......

• I do not have any interest or involvment of any kind in Resmed, other than as a user who purchases their products on the commercial market.
  
  I do work in the Healthcare sector, in a senior public e-Health Informatics role which has only a general connection to SDB, or no connection to any equipment vendor or retailer.
  
  I am a professional grade member, in good standing, of the Institute of Electrical and Electronic Engineers (IEEE), the Australian Computer Society (ACS), and the Health Informatics Society of Australia (HISA)
  
  I do work on a voluntary basis with Australian organisations whose role is to assist SBD sufferers.

Cheers,

Bill

[DHC]

Do you have any interest, of any kind, to ResMed - other than as a patient using products they manufacture?

As I've said before on a number of occasions......

• I do not have any interest or involvment of any kind in Resmed, other than as a user who purchases their products on the commercial market.
  
  I do work in the Healthcare sector, in a senior public e-Health Informatics role which has only a general connection to SDB, or no connection to any equipment vendor or retailer.
  
  I am a professional grade member, in good standing, of the Institute of Electrical and Electronic Engineers (IEEE), the Australian Computer Society (ACS), and the Health Informatics Society of Australia (HISA)
  
  I do work on a voluntary basis with Australian organisations whose role is to assist SBD sufferers.

Cheers,

Bill

hmmm . . . interesting that you have been asked to address the question "on a number of occasions."

Back OT - did you see anything in the data that you find curious or that raised questions?

[billbolton]

hmmm . . . interesting that you have been asked to address the question "on a number of occasions."

Perhaps when you have been around here for more than a few months, you will have discovered how to use the forum search function....

[jnk]

Bill's emoticons are really good at those eye exercises.

[DHC]

hmmm . . . interesting that you have been asked to address the question "on a number of occasions."

Perhaps when you have been around here for more than a few months, you will have discovered how to use the forum search function....

Bill,

As a further point of interest, you choose to respond to a simple statement in my post - rather than answer my question.

Thanks (anyway).

[billbolton]

As a further point of interest,

DHC

Posts: 124
Joined: Thu Aug 26, 2010 11:32 pm
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[DHC]

As a further point of interest,

DHC

Posts: 124
Joined: Thu Aug 26, 2010 11:32 pm
Gender:
Location:

And your point is

What is it you would like to know Bill?