RE: wildly jagged flow rate curves -- do you see this in your data?
Ok, so I'm kind of leaning towards something positional rather than EPR/PS here -- because that March 24th train wreck is at EPR=3, but back sleeping with no cervical collar. Here is the whole night--
https://www.dropbox.com/s/7s49ctd0kitlyd...l.png?dl=0
Notice from 12:40-12:50 or so is a big cluster, with a littler one at about 12:20, a run of extended flow limits, and then a long run of crazy respiration rates.
And here is 8 minutes spread out starting from about 2:15, where I'm coming out of an extended run of the wacky breathing. At 2:17:50, that looks like arousal and recovery breathing. After a good two minutes of that I finally drop into a more regular normal rythym.
https://www.dropbox.com/s/zt8yod0tubjj62...2.png?dl=0
Here is another 8-minute run as I'm coming down out of an episode.
https://www.dropbox.com/s/e5w2gyidy2yy7x...m.png?dl=0
Again, notice the arousal & recovery breathing kicks me back into a more normal rhythm. This one has pulse-ox data, too, and my heart rate is not low. Again, this is EPR=3 on the autoset.
Here is a much looser zoom, a bit over an hour, that shows the entire incident, starting with normal breathing, crazy respiration rates, then settles back down again.
https://www.dropbox.com/s/bf64miq848pnw3...e.png?dl=0
The heart rate is in 70s/80s throughout.
The hubs and I have noodled around some ideas about how to measure beyond the sensors in the cpap. Hubs says his first instinct would be to put pressure sensors lined up all the way down the hose and up in the mask, too.
I was curious about the sleep study and whether my flow rate curve during the test showed any of the wild gyrations that the cpap machine sees. And whether the belts used might have been able to measure and detect TAA and see if there was anything of that sort going on during that sort of breathing. Of course prying that information out of them is probably impossible!
Also, this is off-topic, the reason that I know that the study was measuring thoracic and abdominal effort is that at the end of my sleep study is a detailed explanation of the scoring and definitions of terms. Because these people are jerks, the study that they sent me was the scan of a printout rather than a pdf, so I had to run it through OCR to turn it back into text. (I took it as a personal challenge, LOL.) Now that I've got it as text, I thought that I'd share -- maybe it would be useful for the archives somewhere?
Quote:OSF SLEEP ADULT SCORING CRITERIA & DEFINITIONS OF TERMS
TECHNICAL ASPECTS OF RECORDING AND ANALYSIS TECHNIQUES: Data was collected using Nihon Kohden digital monitoring systems with Polysmith acquisition software. Continuous recording of 1) EEG from the frontal, central, and occipital scalp regions (F3-M2, F4-M1, C3-M2, C4-M1, 01-M2, 02-M1); 2) Eye movements ( EOG) recording from El-M2 and E2-M 1; 3)Submentalis (chin) EMG; 4) Cardiac rate and rhythm (EKG, modified lead II); 5) Leg EMG (right and left anterior tibialis leg EMG); 6) Snore sensor; 6) Thoracic and Abdominal respiratory effort; 7) Arterial oxygen saturation using pulse oximetry (Sa02); 8) End-tidal (EtCO2) and/or transcutaneous (tcCO2) carbon dioxide monitoring (optional); 9) body position; 10) Synchronized digital audio-video monitoring. A polysomnographic technologist attended (was present) throughout this test. Expanded but still limited EEG channels were added when indicated. The sleep study was recorded and scored following scoring guidelines recommended by the American Academy of Sleep Medicine. Respiratory events were scored tallying respiratory events in accordance with the recommended and alternative rules for scoring respiratory events in children and adults. When appropriate, adolescents (13 years or older) were scored using adult scoring rules.
Sleep Onset: Time in minutes after lights out when the first epoch of any stage of sleep is observed.
Total Recording Time (TRT): Time in bed is from lights out until end of the recording.
Total Sleep Time (TST): Time in minutes from sleep onset until the final awakening less wake after sleep onset (WASO).
Sleep Period Time (SPT): Time in minutes from sleep onset to the final awakening.
Sleep Efficiency (SE): Ratio of the total sleep time/total recording time (TST/TRT), a measure of the percentage of the TRT spent sleeping.
Sleep Maintenance (SM): Ratio of the total sleep time/sleep period time (TST/SPT), a measure of the percentage of the SPT spent sleeping
REM Sleep Latency: Elapsed time in minutes from sleep onset to but not including the first scorable epoch of REM sleep.
% NREM 1 Sleep: Total minutes of NREM 1 sleep divided by total sleep time.
% NREM 2 Sleep: Total minutes of NREM 2 sleep divided by total sleep time.
% NREM 3 Sleep: Total minutes of NREM 3 sleep divided by total sleep time.
% REM Sleep: Total minutes of stage REM sleep divided by total sleep time.
Apnea: A drop in the peak thermal sensor excursion by 90% or greater of baseline, a duration of at least 10 seconds, and at least 90% of the event's duration meets the amplitude
reduction criteria. Classifications:
- Obstructive apnea: Meets apnea criteria and is associated with a continued or increased inspiratory effort throughout the entire period of absent airflow.
- Central apnea: Meets apnea criteria and is associated with absent inspiratory effort throughout the entire period of absent airflow.
- Mixed apnea: Meets apnea criteria and is associated with absent inspiratory effort in the initial portion of the event, followed by resumption of inspiratory effort in the second portion of the event.
AASM Hypopnea rule 1A: A 50 % or greater fall (but less than 90%) in the nasal pressure signal excursion for at least 90% of the event duration from pre-event baseline, the duration of which lasts at least 10 seconds, and is associated with a 3% or greater desaturation or EEG arousal and continued or increased inspiratory effort throughout the entire period.
AASM Hypopnea rule 1B: A 30 % or greater fall (but less than 90%) in the nasal pressure signal excursion for at least 90% of the event duration from pre-event baseline, the duration of which lasts at least 10 seconds, and is associated with a 4% or greater desaturation with continued respiratory effort.
Respiratory Effort Related Arousals (RERA): A sequence of breaths lasting at least 10 seconds characterized by increasing respiratory effort or flattening of the nasal pressure waveform leading to an arousal from sleep when the sequence of breaths does not meet the criteria for hypopnea or apnea. With respect to scoring a RERA the preferred methods for assessing change in respiratory effort are nasal pressure and inductance plethysmography.
Apnea Hypopnea Index (AHI): The mean number of apneas, hypopneas per hour of sleep
Respiratory Disturbance Index (RDI): The mean number of apneas, hypopneas and RERA's per hour of sleep.
Arousal: We score an arousal during sleep if there is an abrupt shift of the EEG frequency including alpha, theta and /or frequency greater than 16 hz (but not spindles) that lasts at least 3 seconds, with at least 10 sec of stable sleep preceding the change. Scoring of arousals during REM sleep requires a concurrent increase in chin EMG lasting at least 1 second.
Arousal Index: Mean number of arousals per hour of sleep calculated by the number of arousals X 60 divided by the total sleep time (TST). We may further specify what caused these arousal (e.g. respiratory events, periodic limb movements, etc.)
Awakening: When more than 50% of a 30-second epoch is scorable as wakefulness and was preceded by at least 10 seconds of sleep.
Desaturation Index (DI): Number of desaturations divided by TST.
Periodic Limb Movement: We score leg movements as periodic if they occur in a series of 4 or more repetitive leg movements each lasting 0.5 to 10 sec. with 5 to 90 sec. from onset to onset of consecutive movements. To score a particular limb movement it must a minimum EMG voltage of 8 uv above the resting baseline before the event. Onset of the leg movement is the point when the leg EMG voltage increases 8 or more uv above the resting baseline EMG voltage. The end of the leg movement is when amplitude fails to less than 2 uv above the resting baseline EMG voltage. Do not score a LM if it occurs 0.5 sec. before or after an apnea or hypopnea.
Periodic Limb Movement Index (PLMI): Mean number of periodic limb movements per hour of sleep which is calculated by the number of periodic limb movements X 60/ total sleep time (TST).
PLM Arousal: We consider an arousal related to PLM if less than 0.5 sec. between the end of one event and the onset of the other event regardless of which is first.
PLM arousals index: Mean number of periodic limb movements associated with EEG arousals per hour of sleep which is calculated by the number of arousal related to PLM X 60/total sleep time (TST).
Hypercapnia: also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood. Carbon dioxide is a gaseous product of the body' s metabolism and is normally expelled through the lungs
Sensors we use to detect respiratory events:
a. We use an oronasal thermal sensor to detect absence of airflow to identify an apnea; if the thermal sensor is malfunctioning, we use the nasal air pressure sensor as an alternative sensor to detect apnea. We confirm this using video-PSG.
b. We use a nasal air pressure sensor to identify a hypopnea or respiratory event related arousals (RERAs). If the nasal pressure sensor is malfunctioning, we use inductance plethysmography or the oranasal thermal sensor as alternative sensors.
c. We monitor alveolar hypoventilation using end-tidal pCO2 and if available transcutaneous pCO2.
d. We monitor oxygen saturation using finger pulse oximetry with a 3-second averaging time.
e. We use respiratory inductance plethysmography to monitor respiratory effort.
f. When titrating positive airway pressure we additionally record CPAP flow.
RE: wildly jagged flow rate curves -- do you see this in your data?
EPR/PS isn't the cause, it just has a history of improving this and the data you posted in other thread supported that it helps you too unless that data wasn't average for you.
The cause is likely some mixture of flow restriction/obstruction, position, bad night etc increasing respiratory effort.
One thing to note is that your heart rate was slightly elevated during that breathing. Before and after your heart rate was regularly below 75 BPM, during it was rarely below this and it appears to go as high as 90. I think that is just a slightly elevated heart rate because of extra effort during the asynchrony/restricted breathing.
Try PS = 0 on your vauto if you don't believe PS has an affect. PS=0 removes all the extra features a vauto offers(timing controls, higher PS, higher pressure etc). At that point the only difference is the colour and letters on the front of the machine and I doubt either makes a difference.
RE: wildly jagged flow rate curves -- do you see this in your data?
The attachment is an annotated image from the second linked item of your post above. I stretched out the 30,000 ft. view and believe it shows your wave shape, as least where sampled, has a lot of NED scooped wave shapes obscured by distant views.
Superimposed cardio effects have to be imagined.
I have no particular qualifications or expertise with respect to the apnea/cpap/sleep related content of my posts beyond my own user experiences and what I've learned from others on this site. Each of us bears the burden of evaluating the validity and applicability of what we read here before acting on it.
Of my 3 once-needed, helpful, and adjunctive devices I have listed, only the accelerometer remains operative (but now idle). My second CMS50I died, too, of old age and the so-so Dreem 2 needs head-positioning band repair--if, indeed, Dreem even supports use of it now.
RE: wildly jagged flow rate curves -- do you see this in your data?
2SB -- I'm not sure I'm buying this... Here's a much more zoomed view of one ending of whatever it is
https://www.dropbox.com/s/yuk5nsil90664s...m.png?dl=0
Between 23:40:10 and 23:40:20 I clearly come out of it, and those breaths later look like they have some NED going, but before that is a much wilder ride than I've ever seen published as "sleep disordered breathing".
Here is a very wide view of what I linked the zoom of the end of:
https://www.dropbox.com/s/w6sdqdnv1vr0ku...e.pdf?dl=0
There's plenty of "normal" ugly on both sides, but what's in the middle looks way uglier to me.
RE: wildly jagged flow rate curves -- do you see this in your data?
I understand, you not buying it, Cathy.
Some of my waves of the kind discussed here are like yours with I-tips that markedly dip below the 0-axis, briefly, between full exhalations, Some are like the latter part of the within- wave NED progression. The two forms mingle, mostly in short runs, and keep company with each other and variant undesirables. The key distinction between your and my deranged waves is how yours mostly rise to a sharp peak so quickly and long before full exhale starts--yielding what I call chair seats (inviting cardio dips?).
Any chance you'd post/dropbox a zoom from the source of that second link: 2021March24_zoom2.png, 02:15:20 to 02:17:4, the zoom filling a 1-inch+ channel window height? I'd like to ponder it and see if my pulmonologist, a partner in a sleep lab, would comment on it and on one of mine that is similar and mixed.
That time span includes waves I think are NED-like as well as about 5 waves with those small "exhalations" between two full exhalations. Corresponding FL, mask pressure and leak zooms, too?
I'm always interested in the waveform transitions, form to form, along with accompanying most-related metrics. Looking at your most recent curves cast suspicion on the sigh waves I've considered completely benign (still think so). But can we relate how they morph into troubling forms, no rather, what factors cause or occur with our breathing disorder to increase and cause wave forms to degenerate? How do mask pressure, FL and leak relate?
Re the two questions:
I've long had sighs the peak I-tip FR of which would begin to drop and then a second inhalation burst would shoot FR sharply higher before the FR sharp dive to 0-axis and peak exhalation rate. I call 'em lop-eared rabbit heads. At 30,000 feet they show up, like old telephone poles sticking up by country roads, all along my
FR curve, varying some from a 10 minute interval. Always gapped, the algorithm never showed confusion. Half of them would have a 0.1 to 0.2 FL flag for, say 8 to ten seconds starting midway beyond the peak exhale FR and the associated FL is often a slinglet a minute away from any other FL.
The attachment is one gone bad, and those like it and worse show up too, mostly noticed as isolated singles too, though also present in disordered crowds
I have no particular qualifications or expertise with respect to the apnea/cpap/sleep related content of my posts beyond my own user experiences and what I've learned from others on this site. Each of us bears the burden of evaluating the validity and applicability of what we read here before acting on it.
Of my 3 once-needed, helpful, and adjunctive devices I have listed, only the accelerometer remains operative (but now idle). My second CMS50I died, too, of old age and the so-so Dreem 2 needs head-positioning band repair--if, indeed, Dreem even supports use of it now.
RE: wildly jagged flow rate curves -- do you see this in your data?
2SleepBeta, I am pretty sure that example you posted was a micro arousal (potentially a RERA due to the flow limitation present) just as starting exhalation. Imo it was a quick deep recovery breath that overfilled lungs and that is reason for the following large fast exhale.
You probably notice this at elevation due to the lower oxygen content and your flow limitations causing more arousals then when at lower elevations.
RE: wildly jagged flow rate curves -- do you see this in your data?
Yes, Cathy, the middle or "3rd quarter" of that view you mentioned is a case all its own.
Your diverse runs of cycling but distinctly different repeating wave deformations suggest to me distinct lateral vs. supine OA differences along with your acknowledged OA's chin tucking sensitivity. I can't recall you writing much about that. My observations and work suggests one positioning configuration, a sweet spot, cuts your work of breathing a lot; accordingly far more rounded wave tips should be evident there.
The work I've done on your inspiration time and duty cycle (data: your dropbox BRP file) shows dramatic changes of duty cycle, starting near 0.8, continuing there, dropping to near 0.5 for a long period and then returning to the near 0.8. The 0.8 runs are gappy and have lots of 0.5 interleaved within them but the 0.5 run is clean. The differences in the overall view, which I believe are accurate, are so stark I've wanted to get additional zoomed in Oscar I and E printouts from you to compare all before posting. If much longer expiration time and lower RR (with less dead space effect) do not accompany the 0.5 level, something is wrong, because gross Ti does not change a lot, though it is grassy.
Anyway, sources vary on the normal duty cycle ratios. I've seen 0.3 cited for sleep and 0.4 for wake, as well as a straight 0.4 as the typical Ti/Total ratio.
Member SevereApnea posted relevant links here, Could a Fractured Hyoid Cause Epiglottis Prolapse=OSAS | Apnea Board, a paper identifying and ranking airway sites where collapse causes a signature waveform deformity and here, How to stop rolling onto my back? | Apnea Board, a paper connecting sleeping position to patency of pharyngeal sites and their collapse in lateral or supine sleep.
A snippet cannot be separated from SA's first linked item so here is the piece URL where the last half of the second paragraph makes the points I intended: Flow-Identified Site of Collapse During Drug-Induced Sleep Endoscopy - CHEST (chestnet.org) That last half speaks to my previous comment about the quick drop from peak inspiratory flow, too little dwell time to increase your TV and have/utilize your most normal longer inspiration time. Again, this line of thought is offered as one possible puzzle piece, the NED -like spots, not the whole thing.
Here's a third link you might look at. I suggest it mainly because the word "paradoxical" is central in this paper about breathing and vocalization disturbances, which I'm guessing might apply to your sleep, not to you awake as a singer: Laryngeal and respiratory patterns in patients with paradoxical vocal fold motion | Elsevier Enhanced Reader
I'd prefer to keep my hi-jack-like stuff out of your thread and be thinking about and commenting on your graphs. Your case deep rips lots of rich, new and old fL and FL ground. As you know, mixing metaphors, I'm at the other end of that "big picture" pole, wanting to look at and ponder "those little squiggles" with super close up zooms (when I don't have data, time, immediate skills or brains to tool up and digest the data). My eyes and 32" TV screen's 1080 resolution just aren't good enough for me to scan at 30k ft, though I like to see the all-in view, too.  But as an older near-brother from Estonia did say, people in hell want ice water.
Right or wrong, my thought is that reading the entrails of FR waves for patterns at transitions and what their associations are will unravel most mysteries. However, we can't get more juice out of the data or its curves if it isn't there or can't even be there because of intrinsic limitations, known and unknown.
@Geer1: A look at other similar instances with dips below zero indicated a slight mismatching of peak mask pressure relative to the mini-FR-drops' start times, peak pressures being about 0.2 seconds early within 1.6 to 1.8 sec Ti's. In my attachment that early peak is at the forward edge, the "cusp" (the short-radius turn), of the chair/"m" seat as is true in some other instances, some not near FLG but with flow limitation evident in tips. Preceding and following those sighs gone bad, there are continual, runs of varying chairs and low to moderate m-tips. My 300 ft elevation is not a factor.
That accompanying short small leak is typical at half-?-my sighs (with P-10, too, though this is from FFM days). Head must bob a bit at the sharp, out of pattern FR changes of sighs, which half-?-the time evoke a small FLG. Just earlier than was shown there were three prominent chairs that triggered the two stepped FL we see ending there too.
I have no particular qualifications or expertise with respect to the apnea/cpap/sleep related content of my posts beyond my own user experiences and what I've learned from others on this site. Each of us bears the burden of evaluating the validity and applicability of what we read here before acting on it.
Of my 3 once-needed, helpful, and adjunctive devices I have listed, only the accelerometer remains operative (but now idle). My second CMS50I died, too, of old age and the so-so Dreem 2 needs head-positioning band repair--if, indeed, Dreem even supports use of it now.
10-17-2021, 01:21 AM
(This post was last modified: 10-17-2021, 01:40 AM by cathyf.)
RE: wildly jagged flow rate curves -- do you see this in your data?
I think I found some nomenclature in the literature -- this might be called the "sawtooth sign". Or "upper airway fluttering". Or maybe not. I can't find a really good definition of these things (most articles I can find abstract but not full texts...) These discussions are measuring it on the flow volume curve rather than the flow rate curve. (Somebody needs to tell these researchers that a picture is worth a thousand words, LOL)
And I've been playing with some OSCAR pictures from last month. I created 2-minute resolution snapshots, and then glued them together into a verrrrrrrrrry long "strip" that shows change over time. I started each strip before the fluttering starts, and continued through until after it ends, to show context.
First, some whole night shots from 9/10, 9/15, 9/17:
https://www.dropbox.com/s/900eidooz98z2y...t.png?dl=0
https://www.dropbox.com/s/o8wszekus6kbtc...t.png?dl=0
https://www.dropbox.com/s/l9sjwelz0i48kl...t.png?dl=0
Here are my "strips" -- three PDFs, should be high resolution. (They are BIG files, LOL)
https://www.dropbox.com/s/8ndrhubva9s5cr...0.pdf?dl=0
https://www.dropbox.com/s/moauu8eoxos25e...5.pdf?dl=0
https://www.dropbox.com/s/tabqmf18o7i99g1/20210917.pdf?dl=0
What's striking is that this isn't a few wonky breaths -- it's not seconds, it's minutes, and often more like an hour or even more.
And it's goosing my heart rate -- you can see it on the pulse-ox graphs...
I'm still wondering if anybody but me, 2SB, & elliotg are seeing these spells, or at least seeing them more than rarely. I know that the AB protocol is not to hijack other people's threads, but I'm really looking to see other people pictures to see if I can get some insight into this that I might be missing. I am also leery of generalizing too much off of my one-person experience. And I have in the back of my head that maybe there is some phenomenon in FFM use where inflating and deflating the cheeks, opening and closing the mouth, causes the pressure measurement at the other end of the hose to bounce around because the whole system is continually changing shape and volume in a way that's totally independent of the breathing rhythm.
(technical note -- you probably need to download those files and view them in one of your computer's image viewers with some serious zoom and scrolling. The images are 5 inches tall by 25-30 feet long.)
RE: wildly jagged flow rate curves -- do you see this in your data?
Oh, and some context -- I can fix this. Here's last night, vauto, cervical collar, first the full night, then showing the spot where the respiration rate jumps a bit. That's a single isolated breath doing something weird -- totally harmless!
https://www.dropbox.com/s/cscp0to30tazgt...o.png?dl=0
https://www.dropbox.com/s/9zgqdi6gixg4kt...m.png?dl=0
RE: wildly jagged flow rate curves -- do you see this in your data?
2SB -- I'm slowly reading through and digesting the links that you published -- thank you!
I wish I could get a handle on what the flow-rate curve measurements mean about what physical process is happening in my airway during these periods where the flow-rate curve is fluttering.
Does anybody know about the belts used in sleep studies, and whether they are able to detect paradoxical breathing? After looking through the technical addendum to my sleep studies, I can find nothing that mentions that they might look for this in the data.
I'm trying to decide whether I should send a MyAir message to Dr SelfImportant and ask for them to evaluate the flow-rate tracings in my two sleep studies looking for flutter, and looking at heart rate data, and looking for signs of thoracic-abdominal asynchronous effort from the effort belts and seeing if there is something going on during the flutter.
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