S9 flow skew bug... Anyone else seeing this?

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
User avatar
Nord
Posts: 569
Joined: Sun Mar 07, 2010 4:30 pm
Location: GTA Canada

Re: S9 flow skew bug... Anyone else seeing this?

Post by Nord » Wed Mar 31, 2010 4:34 pm

bigk wrote:I'm planning on D/L every day and only using one card. Only time I will ever use 2 cards is if I am away from home for more than 7 days.
Sorry... I guess I confused you with someone else that just got their S9...

Nord

User avatar
Nord
Posts: 569
Joined: Sun Mar 07, 2010 4:30 pm
Location: GTA Canada

Re: S9 flow skew bug... Anyone else seeing this?

Post by Nord » Wed Mar 31, 2010 8:40 pm

bigk wrote:I'm planning on D/L every day and only using one card. Only time I will ever use 2 cards is if I am away from home for more than 7 days.
Just so you don't think I'm imaging things... I was thinking of an earlier post that you made that you were giving an example... not actually saying that you were doing that. But I did remember it correctly and thats some progress...

quote - bigk " Which is only a problem if you haven't already inserted the data into Resscan right? So if for examply, I use a SD card and I'm away from home for more than 7 nights (it holds 7 nights detailed data) I can put a new card in after 7 nights. When I get home, I can then download the first card into Resscan and then download the second card, all into the same patient file, just like I do now with the S8 right? So I will not lose any data." unquote

Nord

User avatar
dave21
Posts: 720
Joined: Tue Mar 09, 2010 1:05 am
Location: United Kingdom

Re: S9 flow skew bug... Anyone else seeing this?

Post by dave21 » Thu Apr 01, 2010 2:11 am

3x nights now and no data skewing yet. Unfortunately forgot to power cycle the S9 before use last night (was too tired and wasn't thinking straight) but still let's see how it goes. It will get a power cycle tonight for sure as I've now unplugged it

_________________
MachineMask
Additional Comments: Running AirSense 10 AutoSet CPAP, previously S9 AutoSet and S8 AutoSet Spirit
Image

User avatar
Nord
Posts: 569
Joined: Sun Mar 07, 2010 4:30 pm
Location: GTA Canada

Re: S9 flow skew bug... Anyone else seeing this?

Post by Nord » Thu Apr 01, 2010 7:10 am

So far... so good

Nord

User avatar
DreamDiver
Posts: 2516
Joined: Thu Oct 04, 2007 11:19 am

Re: S9 flow skew bug... Anyone else seeing this?

Post by DreamDiver » Thu Apr 01, 2010 10:23 am

10 second skew at the beginning and end - no skew for events, except the very last one as I turned off the machine.
I'll try pulling the plug today. Yesterday, I noticed the humidifier light stayed on all day (that red/orange/amber-colored one).

_________________
Machine: S9 AutoSet™ CPAP Machine
Mask: Quattro™ FX Full Face CPAP Mask with Headgear
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments: Pressure: APAP 10.4 | 12
Also using quattro full face alternately - standard/medium

User avatar
Nord
Posts: 569
Joined: Sun Mar 07, 2010 4:30 pm
Location: GTA Canada

Re: S9 flow skew bug... Anyone else seeing this?

Post by Nord » Thu Apr 01, 2010 10:48 am

Hi DD

What Dave21 and I are doing now is "power down" the machine at least once a day. I believe that the skewing results from memory within the S9 that either doesn't get cleared properly or manages to corrupt the files that are already written to the card.

I am also only removing the card once per day to DL data to ResScan... there may be some writing to the card by the S9, when the card is inserted. And if the writing takes place more times then perhaps that accounts for some skew. Dave is 3 days in (although 1 slip last night in the power down) and still has no skewing.

I am just about to look at last nights data... I am also waiting till after the session ends at 12 noon to remove the card... just 1 other variable in my test.

I haven't been seeing any other reported cases of corruption of cards since taking care when ejecting the cards from ResScan...

Try the "power down" mode of either pulling the plug or pushing the Flow button for more than 3 seconds after 12 noon and "power up" again before you sleep again.

Nord

User avatar
dave21
Posts: 720
Joined: Tue Mar 09, 2010 1:05 am
Location: United Kingdom

Re: S9 flow skew bug... Anyone else seeing this?

Post by dave21 » Thu Apr 01, 2010 12:00 pm

Actually DreamDiver, that's one thing I guess I should clarify here is that I don't see a large skew, e.g. anything in the minute time frame or anything close to 10 seconds or greater, or missing blocks in the graph like I've seen. What I do notice on each day's graph since formatting the card and power cycling the S9 every night is that at the end of each graph there is a permanent a 1 second skew (Flow ending is 1 second longer than the Minute Ventilation, Flow Limitation, Leak, Snore Index and Pressure).

I think this is within tolerable levels and when I look back over all my previous days there's always been at least an additional 1 second for Flow vs the rest of the data graphs, although maybe the 1 second different is how the Skew starts off, but it doesn't look like it on all the days I've looked back on. My guess is that you power off the machine and there's an additional 1 second for the air flow to stop so that's why the Flow graph is 1 second longer.

Over the past 3 days I haven't seen any further increase in the 1 second mark. In mine you can view it by going into the DETAILED GRAPHS and on the bottom pane zoom in to 10 seconds and in the top pane click on the end of the graph and then scroll down to see the Flow vs the other graphs and you'll see a slight skew of 1 second.

Graph below shows it from 06:29:20 to 06:29:21.

Image

_________________
MachineMask
Additional Comments: Running AirSense 10 AutoSet CPAP, previously S9 AutoSet and S8 AutoSet Spirit
Image

User avatar
Nord
Posts: 569
Joined: Sun Mar 07, 2010 4:30 pm
Location: GTA Canada

Re: S9 flow skew bug... Anyone else seeing this?

Post by Nord » Thu Apr 01, 2010 12:09 pm

dave21 wrote:Actually DreamDiver, that's one thing I guess I should clarify here is that I don't see a large skew, e.g. anything in the minute time frame or anything close to 10 seconds or greater, or missing blocks in the graph like I've seen. What I do notice on each day's graph since formatting the card and power cycling the S9 every night is that at the end of each graph there is a permanent a 1 second skew (Flow ending is 1 second longer than the Minute Ventilation, Flow Limitation, Leak, Snore Index and Pressure).

I think this is within tolerable levels and when I look back over all my previous days there's always been at least an additional 1 second for Flow vs the rest of the data graphs, although maybe the 1 second different is how the Skew starts off, but it doesn't look like it on all the days I've looked back on. My guess is that you power off the machine and there's an additional 1 second for the air flow to stop so that's why the Flow graph is 1 second longer.

Over the past 3 days I haven't seen any further increase in the 1 second mark. In mine you can view it by going into the DETAILED GRAPHS and on the bottom pane zoom in to 10 seconds and in the top pane click on the end of the graph and then scroll down to see the Flow vs the other graphs and you'll see a slight skew of 1 second.

Graph below shows it from 06:29:20 to 06:29:21.
Exactly... when I was looking over my graphs... I found that there was an oddity. Flow generally (80% of the time) started on the same second as it finished. I guessed that it was either a "rounding factor" or flow does not simply stop exactly when we tell it to. One second... I can easily live with that.

Dave21 and DreamDiver do such a great job of presenting problems and solutions... I want to Thank You... not just at the end of solving this Skew Thingy but for your great ongoing support and illustrations... I think its great.

Nord

User avatar
dave21
Posts: 720
Joined: Tue Mar 09, 2010 1:05 am
Location: United Kingdom

Re: S9 flow skew bug... Anyone else seeing this?

Post by dave21 » Thu Apr 01, 2010 12:52 pm

Thanks Nord for words of encouragement, we however might be creating more problems (or questions) than actual solutions in this skew problem, and I'm not sure we'll get to a resolution or even a permanent work around if it's down to the firmware of the S9 but time will hopefully tell. The good thing is many of us are hitting the problem and it's annoying enough to have to work out whats causing it and to try and work around it at least.

There's one additional aspect we also haven't considered that the S9 might actually not be writing anything wrong and there's a bug in ResScan in reading a certain set of subset of data from the card causes it to skew. That wouldn't correlate necessarily though to what I reported in this post which seems to show an irregularity.

_________________
MachineMask
Additional Comments: Running AirSense 10 AutoSet CPAP, previously S9 AutoSet and S8 AutoSet Spirit
Image

User avatar
dave21
Posts: 720
Joined: Tue Mar 09, 2010 1:05 am
Location: United Kingdom

Re: S9 flow skew bug... Anyone else seeing this?

Post by dave21 » Thu Apr 01, 2010 1:01 pm

Also to make sure it's not one of the settings I've changed on the S9 on a particular day that's somehow created a skew, I'm also going to change my pressure and mask on the machine tonight. I've been upping my pressure recently with the Swift FX to get a daily AHI of 0.0 and not sure if it's the Swift the pressure or both, but my AHI has been steadily increasing over the past 4 days so I'm going to return back to the Activa mask and drop my pressure back down to my safe point which I know is good.

Tonight will be a good test to see with power cycling and changing the above settings whether I see any kind of skew at the start, mid point or end of the graphs.

_________________
MachineMask
Additional Comments: Running AirSense 10 AutoSet CPAP, previously S9 AutoSet and S8 AutoSet Spirit
Image

fiberfan
Posts: 263
Joined: Sat Feb 13, 2010 2:50 pm
Location: UT

Re: S9 flow skew bug... Anyone else seeing this?

Post by fiberfan » Thu Apr 01, 2010 1:17 pm

I looked back and have a skew I wasn't noticing - I wasn't looking close enough at the flow data. I formatted my card with windows and put it back in the machine. I will check tomorrow.

_________________
Machine: S9 VPAP™ Auto BiLevel Machine
Mask: Zzz-Mask SG Full Face CPAP Mask with Headgear
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments: ResScan 3.14 and SleepyHead software.
So many ideas, so much fiber, so little time - http://fiberfan.blogspot.com/

User avatar
dave21
Posts: 720
Joined: Tue Mar 09, 2010 1:05 am
Location: United Kingdom

Re: S9 flow skew bug... Anyone else seeing this?

Post by dave21 » Fri Apr 02, 2010 12:06 am

Good news is 4x nights and still no skew happening >1 second.

- Still keeping my SD card write protected when inserting into PC
- Still power cycling the S9 prior to use

_________________
MachineMask
Additional Comments: Running AirSense 10 AutoSet CPAP, previously S9 AutoSet and S8 AutoSet Spirit
Image

User avatar
Nord
Posts: 569
Joined: Sun Mar 07, 2010 4:30 pm
Location: GTA Canada

Re: S9 flow skew bug... Anyone else seeing this?

Post by Nord » Fri Apr 02, 2010 8:32 am

Hi Dave

Same here... for 2 days no skew.
I am doing slightly different as test... not locking card and I have played with data in ResScan by deleting and re-entering.
But... I am powering down and removing card once per day after all sleeps during that session have ended and before my next session.

Again...
I am noticing in 5 out of 5 "sleeps" ... that the FLOW always begins and ends on the same second as it begins
All Detailed (not Index) in 5 out of 5 "sleeps" ... that all begin 2 seconds late and end at same second as the FLOW.
The Apneas are correctly placed...

Going away for 4 days so card will remain in machine... I will power down before next session but leave card in machine and use the S9 during travel.

Keep up the good results...

Nord

User avatar
DreamDiver
Posts: 2516
Joined: Thu Oct 04, 2007 11:19 am

Re: S9 flow skew bug... Anyone else seeing this?

Post by DreamDiver » Fri Apr 02, 2010 10:51 am

15 seconds... I don't know what I'm doing wrong. I'd better re-read what our current best practices are.

_________________
Machine: S9 AutoSet™ CPAP Machine
Mask: Quattro™ FX Full Face CPAP Mask with Headgear
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments: Pressure: APAP 10.4 | 12
Also using quattro full face alternately - standard/medium

User avatar
dave21
Posts: 720
Joined: Tue Mar 09, 2010 1:05 am
Location: United Kingdom

Re: S9 flow skew bug... Anyone else seeing this?

Post by dave21 » Fri Apr 02, 2010 10:59 am

Is it the flow again that's skewed by 15 seconds?

Was the previous night okay and last night it jumped from no skew to 15 seconds?

If yes, did you do anything different in the last day?

Thanks
Dave

_________________
MachineMask
Additional Comments: Running AirSense 10 AutoSet CPAP, previously S9 AutoSet and S8 AutoSet Spirit
Image