Hello Guest, Welcome to Apnea Board !
As a guest, you are limited to certain areas of the board and there are some features you can't use.
To post a message, you must create a free account using a valid email address.

or Create an Account


New Posts   Today's Posts

Replaced my ASV, not happy, need help
#51
RE: Replaced my ASV, not happy, need help
Well my humidity hypothesis worked partly, in that the lower temp did increase the humidity without rainout. But the breathing situation didn't improve. But I discovered something weird, which is that the machine keeps dropping the PS below the set minimum, sometimes down to zero. I actually watched it on the screen, and when I looked back over the Oscar graphs it happens multiple times in a night. When it does I experience it as a cutoff in air. There is probably some rationale for it as looking back on graphs for my old machine it did happen occasionally, maybe 2 or 3 times a night. But this one seems to go into a feedback loop where it happens over and over--that's what was going on the night that was so bad--the airplane "flat spin." 
   

So I really think something is wonky with this machine. Fortunately the provider (Supplier #2) has been very responsive. Though they are skeptical about the machine being the problem, they are replacing it for me. The respiratory therapist there did say that, although they support people being able to control their own devices, that ASVs are extremely complicated and less amenable to setting changes -- so it's possible that my attempts to tweak it made it unhappy. In order to head off anything like that, I also talked to my doctor's therapist and she sent them a revised prescription that matches what was working for me before and that I had done with my doctor's full support and cooperation--somehow that had not gotten communicated to the therapist so the original prescription was close to the factory defaults.

So. I should have the new machine, with the revised settings, tomorrow, to wit:
EPAP min 5 max 8
PS min 4 max 13.

Will keep you posted.Wish me luck!
Post Reply Post Reply
#52
RE: Replaced my ASV, not happy, need help
Congrats on the replacement going forward. It's a shame that you had to deal with that, but hopefully with that replacement unit, all would trend positive very soon. Post up data on this new one when you're able. I think it's OK to just plug in your settings from whatever your most recent good ones are and see what happens. With the new one operating correctly, we ought to get you dialed in pretty quickly to give consistent best numbers and feel.
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.
Post Reply Post Reply
#53
RE: Replaced my ASV, not happy, need help
"But I discovered something weird, which is that the machine keeps dropping the PS below the set minimum, sometimes down to zero." - bemused

this was jaswilliams' response when I asked about this:

"The pressure support line dropping to 0 Is a data issue coming from the Resmed.

If you look at the mask pressure line you will see the pressure support is still at or above the minimum values. This issue has been observed elsewhere nothing you can do about it"
Post Reply Post Reply
#54
RE: Replaced my ASV, not happy, need help
Wow, that's very interesting. Can you explain (or post a link to) the difference between machine pressure and mask pressure?
Post Reply Post Reply
#55
RE: Replaced my ASV, not happy, need help
And also I wonder how that jibes with my experience, which is that I wasn't getting any air.
Post Reply Post Reply
#56
RE: Replaced my ASV, not happy, need help
sorry, I can't answer your questions. hopefully one of the more experienced members can.
Post Reply Post Reply
#57
RE: Replaced my ASV, not happy, need help
(11-06-2019, 02:10 PM)bemused Wrote: But I discovered something weird, which is that the machine keeps dropping the PS below the set minimum, sometimes down to zero. I actually watched it on the screen, and when I looked back over the Oscar graphs it happens multiple times in a night. When it does I experience it as a cutoff in air. There is probably some rationale for it as looking back on graphs for my old machine it did happen occasionally, maybe 2 or 3 times a night. But this one seems to go into a feedback loop where it happens over and over
 

When I see this behavior from the ASV it looks like me like the ASV algorithm has hit a limit or condition that triggered "a complete, start from zero again" reset.

So I don't think this signals an issue with the machine (this ASV vs a different ASV).  Especially if you look at the charts in a 2 min view with you see it drop to zero and can see where, how or why the algorithm reset.  

Yes, I do believe you saw this reset happen a good number of times the other night when, during leaks in response the ASV eagerly took more advantage of the available PS Max to boost PS to a level from which it could not maintain it's composure as the leak ended.

I do not believe it is a feedback loop.  I believe the ASV just continues to respond to what it sees in the same way over and over, and .. over and over again the ASV algorithm hits the 'abandon ship' limit condition, resets to PS to zero, quickly lifts PS back to your Min value and then slowly starts to climb like when you first turn the machine on.  

Tying it all together with previous posts:  I see this ASV composure failure recovery reset occur much less when the range between PS Min and PS Max is smaller.   With PS set to 2.4-7.4 I see this same end of leak or end of flow limit condition happen and the ASV maintains it's composure very nicely.  Which is one of the reasons I was pushing to get the PS Max as low as you can get it. 

It will be interesting to see if you see any differences in the two ASV machines or if they operate in exactly the same way.  

I know this is a big hassle.  Hope you see good success soon.  

WillSleep

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply
#58
RE: Replaced my ASV, not happy, need help
It would be interesting to see the mask pressure and pressure on this chart to verify if they confirm the loss of pressure support.
Sleeprider
Apnea Board Moderator
www.ApneaBoard.com

____________________________________________
Download OSCAR Software
Soft Cervical Collar
Optimizing Therapy
Organize your OSCAR Charts
Attaching Files
Mask Primer
How To Deal With Equipment Supplier


INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply
#59
RE: Replaced my ASV, not happy, need help
for the sake of discussion, I've attached a screenshot with zeroed pressure support.  it does not appear to be related to leaks.  mask pressure shows no loss of ps.
Post Reply Post Reply
#60
RE: Replaced my ASV, not happy, need help
(11-06-2019, 07:46 PM)sheepless Wrote: for the sake of discussion, I've attached a screenshot with zeroed pressure support.  it does not appear to be related to leaks.  mask pressure shows no loss of ps.

Sheepless. Thank you for the post and the screenshot.

Yes, agreed. This is a second, different funky characteristic of the ASV.

Not "end of leak" related but are we sure it is not leak related?

Actually last month I saw this exact waveform from my ASV. 

At that time I had a long running leak only 1 cmH2O higher than the leak in this screenshot. 

ASV was chopping my inspiration attempts into double-tops, a fail then a success, a fail and then a success, and so on.. for me forcing me into a RR of 7-8, of half of my normal 15-16 RR on any xPAP machine.  

And yes during that time PS was dropping to zero and (just as we see here) it was not a full algorithm reset. 

Sleeprider, look back for an email I sent you a few weeks back this topic.   This screenshot is the "example from a second person" I was looking for at that time. 

Sheepless, did your Minute Vent drop during this time on that chart? On mine a month ago it did which is what prompted me to find this same waveform/leak/RR pattern.

WillSleep

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Happy Thanksgiving. Big Guy 9 579 11-25-2023, 07:16 AM
Last Post: FLcracker
  Happy Anniversary...well...almost. David Clark 1 435 12-28-2022, 10:11 PM
Last Post: Sleeprider
  Buying used vauto with replaced motor? fishfinderG 1 579 12-06-2022, 09:15 PM
Last Post: Nightynite
  Happy Thanksgiving! Big Guy 9 794 11-24-2022, 10:52 PM
Last Post: Homerec130
  [Equipment] PR System One replaced with Löwenstein Prisma 25S tolnaiz 18 4,284 04-28-2022, 03:20 AM
Last Post: tolnaiz
  Happy to Share This :) Abletree 3 679 04-26-2022, 03:46 PM
Last Post: Jeff8356
  I took apart my Philips Dreamstation and replaced the foam chamber. Now it's loud! allistairt 11 2,916 02-06-2022, 05:42 PM
Last Post: Phaleronic


New Posts   Today's Posts


About Apnea Board

Apnea Board is an educational web site designed to empower Sleep Apnea patients.