Skew flow bug may be due to SD card speed...

[bigk]

This is good standard practice:

Its just your personal desired practice, not any standard and by no means established that it is necessarily better or worse than other ways of using a S9

Cheers,

Bill

They certainly would not be Resmed's recommendation.

You know - I agree with Bill. I don't do 1/2 of what is "recommended". I DO power down the S9 with a 3 second on/off every day after it has cooled down for a while. I may get a little "skew" but I can honestly give 2 shits about that. Really I get all the info I need from the summary screen anyway - the nice pretty graphs are nice but I don't care if they don't match exactly.

[Nord]

This is good standard practice:

Its just your personal desired practice, not any standard and by no means established that it is necessarily better or worse than other ways of using a S9

Cheers,

Bill

They certainly would not be Resmed's recommendation.

You know - I agree with Bill. I don't do 1/2 of what is "recommended". I DO power down the S9 with a 3 second on/off every day after it has cooled down for a while. I may get a little "skew" but I can honestly give 2 shits about that. Really I get all the info I need from the summary screen anyway - the nice pretty graphs are nice but I don't care if they don't match exactly.

I didn't realize that you knew what ResMed's recommendation would be...

Just what exactly are ResMed's recommendations... I wonder ???
Since you and Bill seem to know... perhaps you could share that info.

Many people here do care whether it matches properly... At what point does the inaccuracy of a medical device become important for you

Cheers

Nord

[DreamDiver]

...
Many people here do care whether it matches properly... At what point does the inaccuracy of a medical device become important for you ...

bigk and billbolton bring up some good points.
We should be clear. These are Debugging best practices - certainly not daily-live-your-life-with-your-S9 best practices. If you're interested in helping, debugging best practices help achieve a standard so we can eliminate causes of a bug. Those who have an interest can do so. Everyone else can be happy doing whatever trips their trigger. As bigk points out, there's plenty of feedback right off the screen. The rest is gravy.

Our in-the-field look at this is actually helping ResMed. They really are paying attention to this forum. This is a geeky thread for people who are interested in helping. Participation can happen on many levels: Ignore these debugging threads altogether, just follow along, offer perspective, or follow debugging best practices and try to help out by looking very closely at the data. There is no wrong way to participate or not participate except to be a blue meanie. Fortunately, that hasn't happened yet.

[Nord]

Still Skewing Progressively...

Apr 13th... 1 - 7 Mask Sessions - Skewing up to 3 seconds... Missing No Data... Flow now starts on Odd Seconds...

Apr 14th... 8 - 20 Mask Sessions - Skewing up to 17 seconds... Missing 50 seconds and 46 seconds... Flow now starts on Odd Seconds... 1 Hypopnea out of position

Apr 15th... 21 - 23 Mask Sessions - Skewing up to 21 seconds... Missing 45 seconds and 43 seconds and 41 seconds... Flow now starts on Odd Seconds... 1 OA severely out of place

Nord

[DreamDiver]

Still Skewing Progressively...

Apr 13th... 1 - 7 Mask Sessions - Skewing up to 3 seconds... Missing No Data... Flow now starts on Odd Seconds...

Apr 14th... 8 - 20 Mask Sessions - Skewing up to 17 seconds... Missing 50 seconds and 46 seconds... Flow now starts on Odd Seconds... 1 Hypopnea out of position

Apr 15th... 21 - 23 Mask Sessions - Skewing up to 21 seconds... Missing 45 seconds and 43 seconds and 41 seconds... Flow now starts on Odd Seconds... 1 OA severely out of place

Nord

No skew in the events yet, but I'm still seeing progressively longer skew in other detailed data too - though not as skewed as yours. That's a lot of mask events for one 24-hour session eh? That seems to indicate the problem is related to the increasing number of mask events recorded on the card from the time of most recent card reformatting.

[Nord]

No skew in the events yet, but I'm still seeing progressively longer skew in other detailed data too - though not as skewed as yours. That's a lot of mask events for one 24-hour session eh? That seems to indicate the problem is related to the increasing number of mask events recorded on the card from the time of most recent card reformatting.

I have been deliberately having more Mask Sessions. Some of these were as a result of problems with my H5i and testing that.
Some were unintentional as a result of having mask/ sleep problems a lot more than usual.

Higher number of mask sessions definitely "speeds up" the skewing...

As a test... we could get a volunteer who has no skewing to do many mask sessions... and see if skewing arrives. Any volunteers ???

Nord

[kennethryan]

Hey, guys...

Did two nights (plus a nap) on my new equipment.

Aside: I like it! Very quiet (my wife: "is that thing actually on??"), ClimateLine is a massive improvement (first time in forever I haven't woken up with my tongue stuck to the roof of my mouth), and the more aggressive algorithm seems to handle my chronic congestion better (pressure made its way substantially higher than my S8, oddly enough without an appreciable increase in mask leaks).

First night I had one obstructive apnea event, last night I had one obstructive and two centrals. Looking closely at the data I see no skew - assuming I'm looking at the right thing (comparing the flat part of the high-rate flow line against the lollipop event markers).

Will keep monitoring, and will post if anything looks amiss!

[Nord]

Hey, guys...

Did two nights (plus a nap) on my new equipment.

Aside: I like it! Very quiet (my wife: "is that thing actually on??"), ClimateLine is a massive improvement (first time in forever I haven't woken up with my tongue stuck to the roof of my mouth), and the more aggressive algorithm seems to handle my chronic congestion better (pressure made its way substantially higher than my S8, oddly enough without an appreciable increase in mask leaks).

First night I had one obstructive apnea event, last night I had one obstructive and two centrals. Looking closely at the data I see no skew - assuming I'm looking at the right thing (comparing the flat part of the high-rate flow line against the lollipop event markers).

Will keep monitoring, and will post if anything looks amiss!

Hi Kenneth

Our Skew is happening in several ways... When you look at the 10 or 30 second view and see when the Flow and Leak or Pressure start... you will find a 0, 1 or 2 second difference at the beginning of a skewed data. If it is going to skew... it will happen after about 9 - 12 Mask Sessions and the time differences from the start will move to 3 then 5 then 7 seconds progressively. Until the skew begins to move Events and drop some of the Leak and Pressure graphs for 1 minute and onward.

On the upside... it is a wonderful machine that lowers AHI while breathing at the same pace and rhythm as you do. Once we solve this nagging little problem... I'll let you fill in the rest.

Nord

[dave21]

If it is going to skew... it will happen after about 9 - 12 Mask Sessions and the time differences from the start will move to 3 then 5 then 7 seconds progressively. Until the skew begins to move Events and drop some of the Leak and Pressure graphs for 1 minute and onward.

Nord, this might happen for you on a high amount of mask sessions per day, but for me it happens on just 1, so I don't think we can consider this a baseline of when it starts to skew. Plus also the seconds skew isn't always 3, 5 or 7 seconds (e.g. odd), it varies. I see a lot of even skewing.

Thanks
Dave

[Nord]

If it is going to skew... it will happen after about 9 - 12 Mask Sessions and the time differences from the start will move to 3 then 5 then 7 seconds progressively. Until the skew begins to move Events and drop some of the Leak and Pressure graphs for 1 minute and onward.

Nord, this might happen for you on a high amount of mask sessions per day, but for me it happens on just 1, so I don't think we can consider this a baseline of when it starts to skew. Plus also the seconds skew isn't always 3, 5 or 7 seconds (e.g. odd), it varies. I see a lot of even skewing.

Thanks
Dave

Just trying to give Kenneth a general picture about what to look for... I'm sure he'll now be able to recognize a skew event if is is an even number as well. The 3, 5, 7 are not exact seconds... it gives a "general" picture... Yes ???

Nord

[bigk]

Just what exactly are ResMed's recommendations... I wonder ???
Since you and Bill seem to know... perhaps you could share that info.

Their recommendations are not a secret - the instructions attached to the card holder tell you exactly what to do. IE remove it and send it to your DME - which is the same as you just removing it too. Simple really.

Many people here do care whether it matches properly... At what point does the inaccuracy of a medical device become important for you

I'd be concerned if it affected my therapy in any way whatsoever. Otherwise as previously stated, my concern amounts to 2 shits.