Help: AirSense 11 "Thumps" on exhale?

[Aero Man]

My story - Got new Dreammaker Dec 2020 (used successfully until PR recall) and stopped using it the day after the recall in June 2021.  I vowed to switch over to ResMed and brought an "AirSense 11 Autoset USA" home yesterday (Sep 2021).  My DME set up the AS 11 based on my latest prescription for the Dreammaker and the new AS 11 performs as expected, except that at the end of my exhale, there is now a noticeable "thump" sound/vibration - didn't have this with my Dreammaker.  I went into the AS 11 clinician menu and turned EPR off (is that equivalent to PR Flex?) but I still have the "thump" at the end of exhale, so I turned the EPR back on.  My MASK:  ResMed Airfit F30

Following are the orig settings from the DME for the new AS 11 which I have not changed:
Mode:  Autoset
Pressure Range:  14.0-19.0
Autoset Response:  Standard
Ramp time:  Auto
Start pressure:  7.0
ERP:   "On"
ERP Type:  "Full time"
EPR Level:  3
...
Mask Setting:  Full Face
...
Smart Start: "On"
Smart Stop:    "On"

Any ideas on how I can get rid of the annoying "thump" at the end of my exhale?

[Gideon]

There is a big difference between PR and ResMed devices. One of those is in how it handles the changes between inhale and exhale and inhale.
PR machines anticipate when you should be initiating your inhale or exhale. ResMed Machines sense when you change between inhale and exhale. The difference can be a bit dramatic. Try to simply just practice breathing, take long slow breaths and the short and rapid, take deep breaths, and then take shallow breaths just to learn your new machine.
The other big difference is ResMed's more aggressive algorithms. This usually results in PR users pressures being lower on ResMed devices once dialed in.

EPR vs Flex, as comfort features pretty similar but therapeutically very, very different. EPR acts like Pressure Support on a BiLevel and actually treats hypopnea, Flow Limits, RERAs and UARS.

[Aero Man]

Thank you for this information (sorry, late into the evening here and I mistyped "dreammaker" when I meant "dreamstation".  You are kind for not pointing out my error, but I am.

I'll be watching for when OSCAR is "AirSense 11 - compatible" - sounds like you are in "beta" now so it must be close.  Hmmm, I am using the active modem for my sleep doc's remote monitoring; but I asked for and received a SD card from the DME as well; but not yet installed. After I install the SD card, can I assume that while the modem is active, the data is ALSO being written to the SD card?  My intent is to use the SD card with OSCAR while still transmitting data via modem for the doc to see.    thx!

[StevesSp]

This sounds like a mask valve problem to me, called the 'Anti-Asphyxia Valve'. Make sure it is inserted properly and working as it should. If I don't reinsert mine correctly after cleaning, I get that 'thump' effect on exhale. If it's inserted properly, check the flap isn't damaged or has come adrift.

[Aero Man]

Ah-ha...hadn't considered the mask valve (two small flaps) as the culprit but that also makes sense since the thump is at the end of my "exhale"; just before I transition to an "inhale".  Thanks for the great idea and I'll check for a valve issue on my mask.

I'm new to ResMed (always been a PR user: M-Series, then System One, then Dream Station) so I am surprised to learn of the design differences between PR and ResMed that Gideon highlighted for me.   Thanks again!

[pholynyk]

Since you have an SD card, you can leave it in the machine collecting data every nigh until you have the new version of OSCAR.

The card must be in the machine to collect the detailed data that gets presented in the Graphs. The SD card data collection is entirely separate from the data that gets sent by the cellular modem.

[Aero Man]

Great news that on the AirSense 11, inserting a SD card does not override the functionality of transmitting data via modem. My DME felt I didnt need the SD card but my persistence overcame their objections and they provided the SD card.  ResMed-branded SD card going into AirSense 11 today so when OSCAR becomes "AirSense 11-compatible", I'll be ready.  I appreciate your feedback and thanks!

[Sleepster]

The A10 has that thumping problem due to the lid on the water chamber not being fully closed. Try removing and re-inserting the water chamber.

[Melman]

With the AS10 not having the water chamber firmly seated in the machine will also result in the thump you describe.

[Aero Man]

Got it - thanks!!!!