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UNCLASSIFIED APNEA
#11
RE: UNCLASSIFIED APNEA
(07-24-2021, 02:31 PM)staceyburke Wrote: Flow limits are not reported, it does show a graph. Flow limits are smaller apnea.  If you have a lot they can stop you from getting into deep sleep and cause fatigue. Maybe you should show a recent OSCAR.

Thanks
Two points:
 
1.     Regarding the Flow Limit , I can’t understand why you say  they are  smaller apneas if the event flag graphic doesn’t show them. In fact . more than once, this graph shows 0.00 AHI’s , yet the Flow limit graphic shows several clusters throughout the night rising  above 0.00 , between 0.00 and 0.33 on the Y axis. If this means small apneas, I don’t understand why they are not shown in the event flag graph.
2.     Ref. Large leaks: Resmed defines large leaks as those above 24 l/min for 20-35% of the total sleep time.
Sleepy Head gives a comprehensive view of each night’s  LL in the Leak Rate graph, but how can I view  the exact total duration of these LL each night, in order to see whether or not it is  below  20% of the total sleep time? The Events tab gives a detailed list of each LL event and its duration in seconds, but no total is given. I have to add them up manually, which can be long. Is there a faster way to  go?
 
Thanks
 
Ittiandro
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#12
RE: UNCLASSIFIED APNEA
My way of thinking on flow limit versus Apnea is that flow limits aren't a timed event whereas Apnea are timed and must last at least 10 seconds or it's not Apnea.

For the large leaks, I don't have a solution in a calculation or summing the duration. But I tend to have looked at the leak graph and left panel leak values, looking for an estimate of if present, and how long leaks were present at or over the redline. With my Vitera mask, I typically got about 10 for my leaks on the ResMed AirCurve 10 ASV. 10 is enough of a cushion away from the 24 redline for me. And my ASV did have a few high pressure bursts as it goes about combat of all my Apnea. My most used settings were EPAP 8-13 PS 3-15 IPAP 11-28. Mine actually can't hit IPAP 28, but some CA busting bursts were 20-25 cmH2O, and my leaks as I said averaged 10.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEBSITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#13
RE: UNCLASSIFIED APNEA
I have how they classify apnea in my signature - take a look at it.
Apnea (80-100%) 10 seconds, Hypopnea (50-80%) 10 seconds, Flow Limits (0-50%) not timed  Cervical Collar - Dealing w DME - Chart Organizing
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#14
RE: UNCLASSIFIED APNEA
On Flow Limits.

reports what the manufacturer records on the SD card. PR does report FL as events, though at a much lower rate than we visualize when viewing the flow rate curve. All "restricted" breathing could be considered flow Limits. Let's start classifying them from the worst.
Let's call all restrictions between 80 and 100% that last 10 seconds or longer Apneas.
Now let's call all restrictions between 50 and 80% that last 10 seconds or longer hypopneas.
What's left? Flow limitations.that leaves a lot of territory. The first obviously is all those that are between 50 and 100% but less than 10 seconds. Then there are the remaining 1 to 49% restriction of any time length.

We have seen evidence in the form of patent applications from ResMed that they are continuing research into flow Limits so they can better catch them.

Many of us here resort to reviewing the flow rate chart to identify flow limits. The first question is what is normal inspiratory breathing? Look at the OSCAR logo. Within the "O" are several "ideal" breaths. Note the smooth form above the red zero line. We look for abnormalities, bumps or distortions to that line as indication of flow limits. There are charts that identify different patterns here and what the imply. We stayed percentages of normal airflow above. What is normal? Your normal is likely very different from mine. Our machines use a moving average, ResMed uses 3 minutes (I think) except for the ASV which uses 90 seconds to determine normal. What happens with a reduced flow for an extended period? Oops, normal is reset to the lower value resulting in underreporting events as described above. ,

I hope this brief explanation helps you understand a bit better.
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#15
RE: UNCLASSIFIED APNEA
[url=http://www.apneaboard.com/wiki/index.php?title=Soft_Cervical_Collar][/url]
(07-24-2021, 11:59 PM)staceyburke Wrote: I have how they classify apnea in my signature - take a look at it.

Sorry, I cannot understand what the below percentages ( Apnea, Hypoapnea and Flow limit) mean:
Apnea (80-100%) 10 seconds, Hypopnea (50-80%) 10 seconds, Flow Limits (0-50%) not timed

From reading the SleepyHead Guide at
http://www.apneaboard.com/wiki/index.php?title=Beginner%27s_Guide_to_SleepyHead#Leaks

I  get the sense that large leaks over 20% of the total sleep time may hide apneas,  by interfering with the Flow Rate , i.e the large leaks may obscure  the in- and out-breathing pattern. I don't understand this interaction, but   I noticed that these LL  in the Event Flag graph gray out the Flow Rate graph at the corresponding time zone. It may be an indicator of possible hidden apneas, but if there, they may be really very short and I don't know how relevant they could be. I am not too sure.

For the month of July I have found several LL between 28-30% of the sleep time, some at 38% up to 58%.
I don't have a clue of the cause. My CPAP  mask is about a year old, the straps used to come off at times,  but I adjusted them and fastened them with a piece of tape. They fit comfortably.
All this is CPAP technology is very interesting for an inquiring mind, but also terribly complicated for a layman. In the end, I should be perhaps less theory-oriented  and go by how I feel  after a night's sleep.
I'll focus on the LL, though, and try to correlate them to how I feel at wake up.

Also, Sleepy Head has a Flow Rate  graph, while Oscar has a Flow Limit display.  Are they the same thing?

Any comments or clarifications are welcome

Thanks


Ittiandro

Ittiandro
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#16
RE: UNCLASSIFIED APNEA
Flow Rate isn't interchangable with flow Limit. These are 2 different data charts.

Leaks are likely an issue that can be the mask itself. The cushion will need replaced if it's continually leaking. Taping it together sounds inventive and frugal, but it may be time to look closely and replace with out parts.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEBSITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
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#17
RE: UNCLASSIFIED APNEA
Both SH and OSCAR have the same charts. Flow Rate Charts and Flow Limit Charts are in both. There is a difference that depends on what Brand/model you are comparing.

Apnea 80-100% restricted for 10 or greater seconds. 100% means no flow, complete blockage.
Hypopnea 50-80% restricted for 10 or greater seconds.
Flow Limits (not flagged) 1-50% restricted not timed. Actually includes 50-100% restricted but less than 10 seconds.
Think of these as being a continuum of the same type of event.
The Leak Rate chart gives hints as to the cause of leaks. Peaks usually mean mask leaks, plateaus or tables (fairly flat tops) usually mean mouth leaks/breathing.
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