Why doesn't my S9 respond?

[cortez356]

I have been fortunate to quickly ( 6 weeks) adjust fairly well to my APAP therapy. I have been using my S9 since Nov. My AHI averages 0.6. Leaks are well within any standards I have seen. Other than a huge leak when the mask moves ( now using an Activa LT) leaks are minimal. Some days Rescan shows no events and sometimes 2 or 3. I have watched the excellent tutorial and was fooling around with Rescan this morning. One of my events(obstructive) lasted 18 seconds yet my machine did not respond. Pressure remained at the bottom of the graph. The 2 other events were similar. I know that I am using a wide pressure setting( 6.8 to 14) but isn't 18 seconds enought time for the S9 to react. I expected to see where it tried to stop the event but only could not reach suficient pressure. If I am correct then raising my lower pressure setting would not help. Comments appreciated.

Bob

[Pugsy]

Someone with a more in depth understanding of ResMed algorithm can likely explain it in better detail. It is entirely possible that the 18 second apnea happened out of the blue with no indicators that was normally seen while the machine was on the alert for events or their indicators. It is possible that the machine didn't know what to do with it and chose nothing. I don't know response time for ResMed but my Respironics machine doesn't respond abruptly either. Sudden out of the blue or frank apneas showing on the reports may not have the precursors that are needed for the machine to go on the alert to and thus they slip past the defenses.

One would have to dig deep in the ResMed algorithm to see what it chooses to respond to, why it chooses to respond, how long before response and how long the response takes if there is any. There are members here that have a much deeper understanding of the inner workings of the ResMed algorithm and maybe they will stop by and offer their thoughts. It has been discussed in great detail in the past with the S8 machines. I don't know how much difference there might be now with the new S9 machines or if there was much of a change in the overall algorithm with the new machines.

18 seconds is not very long. If the event occurred out of the blue with no usually seen precursors which are needed for the machine to decide what it wants to do, the event will have happened and be gone before the machine has time to respond if it even was going to respond. They don't go from 0 to 60 in a few seconds. More like 0 to 5 in many seconds..
It may also be simply that the event shown didn't meet criteria for a response.

[DreamDiver]

I have been fortunate to quickly ( 6 weeks) adjust fairly well to my APAP therapy. I have been using my S9 since Nov. My AHI averages 0.6. Leaks are well within any standards I have seen. Other than a huge leak when the mask moves ( now using an Activa LT) leaks are minimal. Some days Rescan shows no events and sometimes 2 or 3. I have watched the excellent tutorial and was fooling around with Rescan this morning. One of my events(obstructive) lasted 18 seconds yet my machine did not respond. Pressure remained at the bottom of the graph. The 2 other events were similar. I know that I am using a wide pressure setting( 6.8 to 14) but isn't 18 seconds enought time for the S9 to react. I expected to see where it tried to stop the event but only could not reach suficient pressure. If I am correct then raising my lower pressure setting would not help. Comments appreciated.

Bob

The S9 does not respond to open-airway apneas regardless of current pressure. (They're marked as 'centrals' on the S9.) If you look at the key on the left hand side in the events area, you'll see the different kinds of events that are measured.


I usually have apneas 10 - 12 seconds long with occasional apneas as high as 25. It helps to have an oximeter if you're concerned. I generally don't worry about apneas at 18 seconds unless I get a lot of them. If it's once in a while, I figure it's just a fluke.

In the statistics pane, change the viewing range to one month and look at your median and 95th percentile for Pressure. If my median and 95th percentile readings were close and correspondingly not very close to the 6.8 min pressure, I would consider changing my min pressure to the median. For instance, if median is 9.8 and 95th percentile is 10, I'd raise 6.8 to 9.8 and see how I did.

If you care to post a detailed pane showing a month view and a two week, perhaps we could all look closer together.
The fact that your ahi is below 1.0 speaks volumes - it's very good.

[Lizistired]

I would compare the flow and pressure graphs and see if the pressure at which obstructions occur was consistant, and if so, use that to adjust my minimum pressure.

[360]

I usually have apneas 10 - 12 seconds long with occasional apneas as high as 25. It helps to have an oximeter if you're concerned. I generally don't worry about apneas at 18 seconds unless I get a lot of them. If it's once in a while, I figure it's just a fluke.

Don't want to hijack this thread but do you have a suggestion for the type of oximeter that will give you the types of reports necessary, etc.?

[DreamDiver]

I usually have apneas 10 - 12 seconds long with occasional apneas as high as 25. It helps to have an oximeter if you're concerned. I generally don't worry about apneas at 18 seconds unless I get a lot of them. If it's once in a while, I figure it's just a fluke.

Don't want to hijack this thread but do you have a suggestion for the type of oximeter that will give you the types of reports necessary, etc.?

This is the review I did on the one I bought.
I bought it here, but they don't seem to have it available any longer. Others have tried this one with success. I like to have an oximeter with replaceable-rechargeable batteries. The ones with specialty batteries make it more difficult to recharge and more difficult to replace the batteries - it's more eco-friendly. Others like the wrist version, but this one again uses a non-replaceable lithium battery. All of these use software that allows you to download the night's data and create reports.

[EricinNC]

I have been fortunate to quickly ( 6 weeks) adjust fairly well to my APAP therapy. I have been using my S9 since Nov. My AHI averages 0.6. Leaks are well within any standards I have seen. Other than a huge leak when the mask moves ( now using an Activa LT) leaks are minimal. Some days Rescan shows no events and sometimes 2 or 3. I have watched the excellent tutorial and was fooling around with Rescan this morning. One of my events(obstructive) lasted 18 seconds yet my machine did not respond. Pressure remained at the bottom of the graph. The 2 other events were similar. I know that I am using a wide pressure setting( 6.8 to 14) but isn't 18 seconds enought time for the S9 to react. I expected to see where it tried to stop the event but only could not reach suficient pressure. If I am correct then raising my lower pressure setting would not help. Comments appreciated.

Bob

The S9 series is sluggish from what I have observed. Its not that great of a machine. I would not trust a real low minimum setting to take on my OSA, particularly with a sluggish machine like an S9 APAP. I have watched how long it takes water to go up the tube in my water manometer when I turn on my S9 compared to my older S8 and also compared it to the Phillips Respironics APAP I have. The older S8 APAP and the modern Phillips Respironics shoot the water up there really fast. The S9 takes forever. I dont feel anywhere near the same on the S9.

What I do is keep my minimum the same pressure as my CPAP titrated pressure. That way, response time is minimal and Im one of these guys who likes high pressures anyway. You may find once you adjust to it, you actually LIKE higher pressures. I had problems with severe insomnia for years and found by serendipity, that the pressure from the machine knocks me out to go to sleep fast.

Eric

[DreamDiver]

The S9 serious is sluggish from what I have observed. Its not that great of a machine. I would not trust a real low minimum setting to take on my OSA, particularly with a sluggish machine like an S9 APAP.

cortez356 seems pleased with his S9. He just wanted some background info. The S9 obviously works for a lot of people -- just not you. When you first joined, didn't your profile say you had a System One? What's the deal with that?

[EricinNC]

The S9 serious is sluggish from what I have observed. Its not that great of a machine. I would not trust a real low minimum setting to take on my OSA, particularly with a sluggish machine like an S9 APAP.

cortez356 seems pleased with his S9. He just wanted some background info. The S9 obviously works for a lot of people -- just not you. When you first joined, didn't your profile say you had a System One? What's the deal with that?

What the hell is a system One?

Eric

[EricinNC]

I have been fortunate to quickly ( 6 weeks) adjust fairly well to my APAP therapy. I have been using my S9 since Nov. My AHI averages 0.6. Leaks are well within any standards I have seen. Other than a huge leak when the mask moves ( now using an Activa LT) leaks are minimal. Some days Rescan shows no events and sometimes 2 or 3. I have watched the excellent tutorial and was fooling around with Rescan this morning. One of my events(obstructive) lasted 18 seconds yet my machine did not respond. Pressure remained at the bottom of the graph. The 2 other events were similar. I know that I am using a wide pressure setting( 6.8 to 14) but isn't 18 seconds enought time for the S9 to react. I expected to see where it tried to stop the event but only could not reach suficient pressure. If I am correct then raising my lower pressure setting would not help. Comments appreciated.

Bob

My Resmed S9 takes over thirteen seconds from the time I hit the "on" button to climb to a pressure of 9.9. My old Resmed S8 APAP took slightly over three seconds to do the same. My Phillips Respironics APAP with A-Flex takes about three seconds, if that, to go from the on button to a pressure of about 10.3.

The S9 series is slow.

Eric

[BernieRay]

...
The S9 series is slow.

That's just one person's opinion. The S9 works great for me.

[Wulfman]

I have been fortunate to quickly ( 6 weeks) adjust fairly well to my APAP therapy. I have been using my S9 since Nov. My AHI averages 0.6. Leaks are well within any standards I have seen. Other than a huge leak when the mask moves ( now using an Activa LT) leaks are minimal. Some days Rescan shows no events and sometimes 2 or 3. I have watched the excellent tutorial and was fooling around with Rescan this morning. One of my events(obstructive) lasted 18 seconds yet my machine did not respond. Pressure remained at the bottom of the graph. The 2 other events were similar. I know that I am using a wide pressure setting( 6.8 to 14) but isn't 18 seconds enought time for the S9 to react. I expected to see where it tried to stop the event but only could not reach suficient pressure. If I am correct then raising my lower pressure setting would not help. Comments appreciated.

Bob

Riiiiight! And, "Nope". If there were no preceding events (flow limitations or snores), the chances of it responding to a "frank" (abrupt, out-of-nowhere) apnea are slim to none......and "Slim" is outta town.
You would be wise to raise your lower pressure to head off some of these events (prohibit them from occurring in the first place). Why have your machine pressure bouncing around all night disturbing your sleep?


Den

[cortez356]

Thanks for all the replies. I have an oximeter but do not wear it every night. I was not overly concerened with those events Just needed an explanation. They were marked as obstructive. I havent changed my settings because I am a "chicken". My results are excellent and sometimes I dont even check them in the morning. I guess I am afraid to spoil a good thing! I know that is silly as I can always go back to the original settings but that is just me. I am going to be traveling for 2 days but after that I think I will up the pressure by 1 for say 5 days and then if all is well repeat by one more. My 30,60 and 90 day pressures are almost the same. Median is 9.3, 95h is 13.1 and max is 13.9. AHI for last 30 days was 0.6. I have never noticed when the S9 increases the pressure. Doesn,t wake me up. I will report back in a week. Thanks again!


Bob

[Lizistired]

With an AHI that good, I wouldn't even raise the minimum in full cm's. I've seen a difference in raising it 0.2 at a time. But l would still base it on the pressure at which the apneas were occuring.

[DreamDiver]

What the hell is a system One?

Eric

I seem to remember that when you first started posting as EricinNC, your profile said you had a Respironics System One Auto. Perhaps I was wrong.