Halfway report on S9 30 day desat test

As some may remember I said I was going to test my S9 Auto in CPAP mode at the same pressure as my S8 Elite for 30 days and record the readings from my pulse oximeter as a way to evaluate the S9 other than " I feel much better ). Feelings being subjective and not reliable.

I thought I would report the results of the first half of the experiment. Remember this isn't scientific, it proves nothing. The desats are being reported by my CMS-50F which is an FDA approved pulse oximeter many of us have.

The data are somewhat skewed because the oximeter reading for the first week of the 30 day period immediately before I started using the S9 are higher than the next 3 weeks. Or, conversely, the last 3 weeks readings were lower than the previous week(s). But, although that week was high, it wasn't unusual for me to have reading like that on the S8.

So, once again these readings don't constitute any scientific basis to make a decision on. They are strictly anecdotal, but made by a machine rather than subjective feelings which are subject to many variances. The pulse oximeter doesn't get enthusiastic because there is a new machine. It just reads the oxygen in the blood and reports what it saw. I'm sure the 30 day desat percentage probably won't be quite as high because that first high week on the S8 will be averaging down with another 2 weeks of data thrown into the average.

First two weeks ( out of 30 day test ) with S8 average reported desats = 6.21
First two weeks ( out of 30 day test ) with S9 average reported desats = 2.21 4.00 less average desats = 64.37% fewer desats reported

All readings taken with the same oximeter. Everything was the same .. same mask, same pressure setting.

It certainly looks as though the S9 is delivering much much better therapy.

I will report in again in 2 weeks after the entire 30 day study is finished. I was somewhat hesitant to report these PRELIMINARY results, but they look so good I couldn't resist

Thanks so much for reporting the preliminary results of your oximeter tests! I am looking forward to the longer-term report as well. So far, this is looking very good for the S9. Do you FEEL any different with the S9?

DreamOn wrote:Thanks so much for reporting the preliminary results of your oximeter tests! I am looking forward to the longer-term report as well. So far, this is looking very good for the S9. Do you FEEL any different with the S9?

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Yes and No. ha ha

That is such a subjective thing.

I seem to have a bit less daytime sleepiness ... most days.
I seem to react extremely slowly to changes.
It took over 2 1/2 years of being a hosehead before I really saw much difference at all.
Goodness knows how many years I had sleep apnea. My first wife reported my snoring and stopping breathing back in 71!
Didn't get diagnosed until 2006.
I had many years of disturbed sleep to try to recover from I suppose.
It just gradually gets a bit better month after month.

I'm looking forward to switching over to APAP mode and seeing how the pressure varies.
I tried an M series awhile back and it showed a 90 percentile pressure of 11 something.
So I've had my S8 set at 11.
I see some centrals so I'm wondering if the pressure is a teeny bit too high.

Thanks for doing this... I'm looking forward to the final results, but I agree this looks promising--and this is just using CPAP mode, eh? I know that since I got my S9, my pressure on APAP gets higher than it did on the S8 because of the response to obstructive apneas. In that sense I think the S9 works better since it is able to respond to events that the S8 did not.

Pressure is pressure. Oxygen levels are a constant on planet Earth (depending on altitude or unless you are on Mars). Resmed S8, S9 or Resperonic... cpap machines are designed to do one thing and that is to supply a given pressure at a given setting. To say that your older machine is supplying insufficient therapy comparing to a S9 is saying the S8 is not working or calibrated properly. It has absolutely nothing to do with the fact that its a S8.

I am looking forward to the complete "study"....

Thanks A-Willie

Nord

valmet49 wrote:Pressure is pressure. Oxygen levels are a constant on planet Earth (depending on altitude or unless you are on Mars). Resmed S8, S9 or Resperonic... cpap machines are designed to do one thing and that is to supply a given pressure at a given setting. To say that your older machine is supplying insufficient therapy comparing to a S9 is saying the S8 is not working or calibrated properly. It has absolutely nothing to do with the fact that its a S8.

From strictly a pressure perspective, I can see how the S9 might deliver better therapy in APAP mode, but in straight CPAP I can't fathom why there would be a difference. But the S9 is billed as having better technology to control temperature and humidity, which may correlate with less congestion, and consequently the improvements that Willie has observed.

Arizona-Willie wrote:It certainly looks as though the S9 is delivering much much better therapy.

Valmet49, El Pap, I agree pressure is pressure but let me allude to what Arizona-Willie is actually saying where he's seeing the difference with the S9 CPAP vs S8 CPAP at the same pressure level.

I was one of the first (maybe the first) person here to have an S9 although I wasn't the first to post about it, and many people doubted what I was saying that the S9 was not only showing lower AHI's (reducing the HI almost to zero) but also making me feel better. Since others started to migrate to the S9 everyone that is migrating is also starting to see the same thing.

Sure the reduced AHI's are an immediate feel good factor and ResMed may have done something to change how they determine what is an HI maybe they were previously taking an HI as 12 seconds and now they're taking it as 10 seconds thus maybe reducing the HI. However, that said, the way the blower works on the S9 is truly remarkable and nothing like the S8 or any other machine. Think of a blower/fan that just shunts air towards you down a tube at high pressure. This is what I would say that most machines are like, including the S8. Now take the S9 that seems almost to send the air down like in a cyclone (twisting the air) the end result is the air hits you much more gently (but it's still the same pressure).

When you put a mask on with an S8 and then do the same with the S9, although the pressure on both machines are identical you notice that with the S9 the wall of air that hits you is no longer there. That's one of the first big changes you see with the S9.

This is part of the new treatment the S9 gives you, with the combined reduction with the AHI's, my AHI's have reduced from a 4.5 average on the S8 to 0.3 on the S9. The treatment is so much better on the S9 but you do have to experience it though to see the massive difference with the S9.

valmet49 wrote:Pressure is pressure. Oxygen levels are a constant on planet Earth (depending on altitude or unless you are on Mars). Resmed S8, S9 or Resperonic... cpap machines are designed to do one thing and that is to supply a given pressure at a given setting. To say that your older machine is supplying insufficient therapy comparing to a S9 is saying the S8 is not working or calibrated properly. It has absolutely nothing to do with the fact that its a S8.

There are a number of false assumptions in your assertion.

First, pressure is not constant at sea level. Without that change, we wouldn't have weather.

Second, you are not considering the algorithms by which pressure changes and EPR/CFlex are being delivered. For instance, I cannot abide by cflex at any capacity on Respironics M-series. It causes my breathing to race all night, giving me a sore diaphragm in the morning. EPR, on the other hand seems to deliver some respite from aerophagia - at least at level one - allowing me to adapt to higher pressures than I might otherwise have been able to endure and still remain asleep.

Third, the method by which pressure is kept continuous differs between respironics and resmed machines too. I find the resmed algorithm to feel more like natural breathing - more comfortable than the respironics algorithm. That said, there are likely differences between the algorithm used to provide pressure between the S8 Autoset II and the S9 Autoset. Physical flow generator design also impacts therapy. Those differences may offer considerable benefit in favor of the S9, as many people seem to be experiencing.

So - Given the pressure at sea level on any given day, the machine is attempting to deliver a constant pressure that is slightly above that of the current altitude and weather conditions, whatever they may be. The method by which it delivers that additional pressure and how our bodies respond can be significantly different from model to model.

Yes, the EPR on the S9 is different than the S9. For one thing on the S9 there is an adjustment for how fast the inhale pressure is applied -- either Med or Fast. On the S8 there was no such adjustment. I left it at the factory set default of Med. Forgot to mention I am using EPR 2. That was the setting on the S8 also.

Not that that makes much difference to the results of the study. Because the study is reporting oximeter readings. Not how I feel, or do I < think > I slept better. The oximeter is giving dispassionate reports. It could care less what machine I'm using or if I'm even using one. It doesn't know anything about the machines. It only reads oxygen saturation in the blood and reports how many times that level dropped below its set point for a certain time which it terms an < event >.

I can only attribute the improvement in that number reported to different algorithms driving the blower motor and perhaps the design of the blower motor. I doubt the humidification is any better than what I was getting using the S8 and the F &P 150 humidier. Nor do I see how the humidity would affect the percent of oxygen dissolved in my blood. The humidification is basically for comfort to avoid dry throat.

And, it may turn out that the drop in O2 desats is only temporary and may have nothing to do with using the S9. They may go back up. Time will tell.
But, if over 30 days using the same mask and the same settings, there is a lower average number of desats, then I think it will offer some evidence of better therapy. Still though that isn't scientific PROOF because it is only one persons results over a very very limited period of time. At best this study could be called an indication of better therapy if it turns out that the numbers stay lower.

Interesting post Willie thanks for sharing your findings.

"anecdotal" I had to look that one up

I am enjoying the use of the EPR on the S9, my minimum pressure is set to 7cm and I have EPR set to 3. My AHI is always below 2 and 90% of events are always central in nature. So i don't see any point in turning down the EPR.

I'll have yet to check my desats with my oximeter & S9, maybe I should try.

Arizona-Willie wrote:For one thing on the S9 there is an adjustment for how fast the inhale pressure is applied -- either Med or Fast. On the S8 there was no such adjustment. I left it at the factory set default of Med. Forgot to mention I am using EPR 2. That was the setting on the S8 also.

On the S8 Elite II and S8 AutoSet II machines there is a Fast/Med setting for "EPR Inhale" (if EPR is on, it's the rate at which pressure returns to therapy pressure during inhalation). It's only available in CPAP mode on the S8 AutoSet II.

Arizona-Willie wrote:Yes, the EPR on the S9 is different than the S9. For one thing on the S9 there is an adjustment for how fast the inhale pressure is applied -- either Med or Fast. On the S8 there was no such adjustment. I left it at the factory set default of Med. Forgot to mention I am using EPR 2. That was the setting on the S8 also.

My S8 -- produced in Sept. 2009 had that fast/med EPR feature.

I can only attribute the improvement in that number reported to different algorithms driving the blower motor and perhaps the design of the blower motor. I doubt the humidification is any better than what I was getting using the S8 and the F &P 150 humidier. Nor do I see how the humidity would affect the percent of oxygen dissolved in my blood. The humidification is basically for comfort to avoid dry throat.

I accept your description of how humidification affects you -- for others, it may have an impact through its effect on nasal congestion -- less congestion leading to better oxygenation.
O.

I should have said that there was no EPR inhale setting on the ORIGINAL S8

I never had the S8 II. Went straight from the Model T to the Ferrari

valmet49 wrote:Pressure is pressure. Oxygen levels are a constant on planet Earth (depending on altitude or unless you are on Mars). Resmed S8, S9 or Resperonic... cpap machines are designed to do one thing and that is to supply a given pressure at a given setting. To say that your older machine is supplying insufficient therapy comparing to a S9 is saying the S8 is not working or calibrated properly. It has absolutely nothing to do with the fact that its a S8.

valmet49,

In one sense what you say is correct. However, there are factors that can and do appear to have ripple effects on therapy results. One very simple difference between an S8 (compared to an S8II & an S9) is the shape of the delivered waveform (the pressure curve). The S8 II & S9 deliver a shaped waveform, it is called the sharkfin waveform and it basically better matches the natural breathing pattern of people. That small difference can have a ripple effect into other aspects of therapy & it is entirely feasible that AW is seeing such a ripple effect.

Cheers

DSM