Aircurve 10 ST-A and Lumis 150 VPAP ST-A just a UK branding difference?

[SingleH]

Hi all,

I see in the UK there is no Aircuve 10 ST- A available and anything with iVAPS functionality is sold under the Lumis name.

Looking at the Oscar compatibility chart I also noticed the two produts are listed together suggesting they are the same : Aircurve 10 ST-A (Lumis 150 VPAP ST-A)

Is the use of Lumis or Aircurve purely a branding exercise depending on the regions where the Resmed product is sold?

Thanks in advance.

[Crimson Nape]

Yes.

- Red

[SingleH]

Thanks for confirming Red!

[McDee]

Well, sort of… they’re very similar machines but the software isn’t quite identical.  The Lumis 150 iVAPS mode has an optional auto-EPAP setting, while the AirCurve ST-A is fixed EPAP only.  Also those two models are the most similar, but the Lumis line has additional model options as well.  Such as the Lumis 150 ST, with the same modes and settings, but without the “-A” alarm feature (and the extra cost and different chassis to fit that).

[StuartC]

Well said McDee

   

I can add to that with some extra details:

• The "-A" refers to alarms that might be used in a care setting.  They are really not of any value to the user who manages the machine themself.  I had this confirmed by someone from ResMed in a conversation prior to purchasing mine.  This is relevant because ...
  
• Where I live, the Lumis 150 ST-A costs 50% more than the Lumis 150 ST.  If it is the same where you live, save yourself the money and just get the ST, not the ST-A 
  
• The Auto-EPAP on the Lumis only works with min PS of 8 or higher.  Maybe that will work for you, but I suspect it is too much for many.
  
• In iVAPS mode, the EPAP reported to OSCAR etc, is the min EPAP that is set for Auto-EPAP,  even when Auto-EPAP is switched off.  So if you change EPAP you need to switch Auto-EPAP on, change min EPAP and then switch Auto-EPAP off.  
  

[McDee]

Thanks Stuart!  Interesting details… I hadn’t heard about that AutoEPAP limitation before, but I see it now in the clinical guide… specifically that the Max PS must be set to at least 8 when using AutoEPAP.  I believe Min PS can still be set as low as 0.  But could still be an issue as you say, especially if the machine actually uses the full range aggressively, versus sticking closer to Min PS in practice.

Have you tried AutoEPAP on the machine, or did that limitation make it impossible?

I wonder why ResMed added the limitation?  Seems kind of strange… it’s not obvious to me.

[StuartC]

That limitation made it impossible.  

Actually, based on what you said, I seem to have said it wrong.  It is actually a min PS range of 8 (oops, sorry, and thanks for the correction).  That is not the same thing as the clinical guide implies because that specifies ranges for both PS min and PS max but does not specify the fact that the two ranges are not entirely independent of each other.  The ASV is the same except there the range is 5.

I set my machine in an unconventional fashion with my PS min set to 5 and PS max set to 7.  I have previously tested with PS max at 8, but it would not let me enable Auto-EPAP and still have PS min set to 5.

I think the reason ResMed added the constraint is because the gain on the PS control loop is quite aggressive, causing overshoot.  When I first started on iVAPS the controller set PS either to PS min, which was too low causing my O2 to drop during REM, or to PS max, which was too high causing CO2 to drop and RR to be suppressed, locking me into the backup respiration rate for something like 30% of the night.  It was never able to establish a "smooth" action for control of PS somewhere between min and max.  I have been wondering if it would do better with a greater range but have not taken that further because PS max can literally be a sore point for me with aerophagia.

I eventually came to realise that the problem I had was actually with Target Va being too high.  However, even with Target Va set "too low", I still see the same over-response in the PS control loop.  I have been wondering recently about trying to find a "Goldilocks" Target Va more in line with the conventional way of setting up iVAPS.  If so, I might consider PS min set to 0, in which case I might still be able to test Auto EPAP.

[McDee]

Got it… thanks for the clarification on the PS range.  I’m familiar with the ASV PS range limitation.  Interesting that ResMed did something similar here, but with an even larger range, and only required for AutoEPAP.

I wonder if they were concerned about EPAP ranges being set too wide or wide open, as is often the case with Auto machines.  With Min EPAP too low for therapy, and too slow to increase per breath.  So require a larger PS range to ensure the machine can still ventilate and respond quickly.

AutoEPAP in iVAPS is kind of an oddball feature in the ResMed line-up.  Mixed into a single mode, instead of separate like CPAP/AutoSet, S/VAuto, and ASV/ASVAuto.  And not released worldwide.  And with this PS range limitation that only applies  to it, and not iVAPS mode in general.

[StuartC]

Yes it is odd that Auto-EPAP is not a separate mode.  But the Lumis is an S9 generation machine, according to the message that appears when you import data (see image), even though it is S10 hardware.  So perhaps the oddity is that the AirCurve ST-A does not have the mode rather than the strange way it is implemented on the Lumis. 

I also wonder why there is no AutoST mode?  Given how useful the backup rate was for me as a safety net when I pushed PS up to try achieve prescribed target volumes, I really appreciate having it available.

[SingleH]

Hi Stuart,

Thanks for your replies.

The models in the UK at least whats listed on the Resmed UK site are the Lumis 100 VPAP ST-A (No iVAPS feature) and Lumis 150 VPAP ST-A

I take it the point your mentioned about the reading of the EPAP figure in Oscar is a "software bug" of sorts?