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AHI < 1.0 now, but still tired? Is it UARS, RERA, arousals or FL in your FR peaks?
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AHI < 1.0 now, but still tired? Is it UARS, RERA, arousals or FL in your FR peaks?
I believe members can collaborate in this thread to assess and deal more effectively with this subject's breathing disturbances now given that much of the necessary information is only two mouse drags away.  There is a ResMed patent signal (just below) that machine-algorithm help may be forthcoming within the next generation or two of their xPAP machines. 

This thread is not a call for my personal treatment help (though it will show my workups of OSCAR graphs, those crude things being all I have for illustrations and questions here). I will start or use a previous thread for my treatment related questions. 

Please contribute to here as our learning space if the thread subject applies to your sleep with low AHI. Contribute if you have questions, corrections, a different interpretation or have other information to share about feeling or being treated for unrestul sleep.

1. I've seen, as Pubmed indicates (2020),  our machines produce and do show untapped information though it is not machine flagged for OSCAR graphs that presently show that information (in the flow rate (FR) curve deformations). We can jointly try to devise a manual method  for seeing and using OSCAR's present display of that information now, while hoping next generation machines will exploit that information to help our sleep. See https://pubmed.ncbi.nlm.nih.gov/32289733/

Each of us must decide how important fixing our sleep is. "Improve your sleep hygiene" is the usual, good recommendation. But at advanced age, one's  remaining pleasures after treatment and reforms can be hard to drop.  Compelling focused evidence from a reasonable trial period of change would sell me. Such evidence would also scratch my continuing itch to learn more about this complex, interesting topic.

2. Dr Park explains detrimental effects of spontaneous and other arousals that cause sleep fragmentation:
https://doctorstevenpark.com/spontaneous...e%20night.

3. Importance of measures and scoring of flow limits (FL) was the focus of a 2017 medical conference: https://www.atsjournals.org/doi/pdf/10.1...1704-318WS

4. Medical (and machine marketing?) importance of metrics, detections and flagging of flow-limit caused deformations of inspiratory flow rate peaks was recognized in the linked 2018 Resmed patent application: https://patentimages.storage.googleapis....2088A1.pdf

What is the problem and what gives rise to it? 

5.  Mainly, it is the Biomechanics of the upper airway. A floppy tube?
https://journals.physiology.org/doi/full...00539.2013

6.  UARS and  RERA definitions are clearly explained: 
https://sleepapneamatters.com/apnea-vs-h...a-vs-rera/

7.  Nature of arousal in sleep, sleep disruptors:
http://www.sciencesleep.org/ziliao/The%2...0sleep.pdf

8. Microarousals. More Sleep disruptors: 
https://onlinelibrary.wiley.com/doi/pdf/...97.00276.x

9. How can we see our flow rate (FR) curve irregularities are causing or contributing to our arousals and micro arousals. Explained here there are 47 classes of normal or more deformed inspiratory FR peaks having 3 levels of severity: normal, moderate and severe:
https://www.hindawi.com/journals/cmmm/2017/2750701/ (Seven broad classes of shape were documented in 2001 by Tero Aittokallio, et al. in Finland, as noted below.)

How does  this and related information fit into information of the kind sensed and compiled in sleep laboratories' reports.

10. Here are two sets of curves. First, the "A" set which summarizes (in a set of 7 synchronized graphs) how the various PSG metrics (EEG, EMG, Pes, Flow, Ventilation and SpO2) all fit together and illustrates how the arousal threshold (ArTH) was "backed into" (with reverse-engineering calculations) to determine (estimate?) and graph the ArTH. OSA sufferers, as shown in "A" have a higher ArTH than UARS and FL affected patients. The patient's ventilatory drive has to reach a higher level to open the obstructed airway. Second, is the "B" set of curves for the low ArTH patient having UARS and FL who tends to awaken (arouse) more easily than the OSA sufferer. Note that the indicated gold standard for determining ArTH is the sleep lab's EMG (diaphragm muscle action measurement) and Pes (esophageal pressure). The A and B curves, showing ventilatory drive, necessarily used the gold standard EMG and Pes curves (standards) and data as baselines to back into the ArTH level. But the graphs include the corresponding EEG power.
https://www.ncbi.nlm.nih.gov/pmc/article...figure/F1/

11. Here is the research abstract of research underlying the A and B sets of graphs in the item above. 
https://pubmed.ncbi.nlm.nih.gov/29228393/

Among other related and significant matters:

12. What level of FL is normal? Indications are that the "cut point" distinguishing Normal from troubled sleepers, is having an AHI<=5 with no more than 30% FL:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3792383/

13. An indication the AutoSet (AirSense AutoSet?) can help identify arousals:
https://pubmed.ncbi.nlm.nih.gov/9817142/

14. A survey reporting about literature on UARS topics:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608900/

15. Early research determining 7 flow rate shapes by Tero Aittokallia et al. of Finland, a bio-mathematician, I believe.
https://pdfs.semanticscholar.org/0c30/43...370be1.pdf

16. Some explanation of brain waves detected and measured in sleep and wakefulness: https://psych.athabascau.ca/html/Psych28...ness.shtml

17. Information about ArTH and related stimuli: https://pubmed.ncbi.nlm.nih.gov/9351134/

18. How low adherence or compliance can stem from low ArTH. PAP not or not seeming to help arousals and sleep fragmentation for UARS, etc.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5940420/

19. Apparently there is a cognitive link between awake arousability and sleep-disturbing arousability.
https://www.sciencedirect.com/science/ar...m%20sleep.


I will post related matter from my OSCAR presentations in a later post.

2SB
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RE: AHI < 1.0 now, but still tired? Is it UARS, RERA, arousals or FL in your FR peaks?
2SB, you've clearly put some time into this. I am very interested in the topic but will admit I'm not likely to immerse myself to a similar degree. consequently, I appreciate the broad brush introduction / summary you've presented and encourage you to continue to give us crib note level summaries, your analyses, hypotheses & conclusions (in addition to the citations for those that want to dig in). I don't know that I'll be able to contribute much to the discussion but I will surely be following along.
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