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Well, I got Ted to read it to me from the manual. The operating modes are as Wader said (Wader, do you have one of these machines sitting by your bed?)

1. Bi-level
2. Bi-level with BiFlex
3. Auto Bi-level
4. Auto Bi-level with BiFlex

So, there's no "straight" cpap mode and no "straight" autopap mode. Bi-level operation in every mode.

Ted's still doing great, btw!

Tks RG, as always zooming in on the absolute facts

You would make a great detective.

I guess we are both a little surprised that it only does BiLevel modes ?.

Tks

DSM

Thanks rested gal and thanks Ted! Mystery solved.

And thanks, wader! Your logic was absolutely correct. (Either that, or you're clairvoyant.....)

neversleeps wrote:Thanks rested gal and thanks Ted! Mystery solved.

And thanks, wader! Your logic was absolutely correct. (Either that, or you're clairvoyant.....)

Nup,

Wader is clearly knowledgeable & consistently so
Yours was a good call Wader

Cheers

DSM

Thanks for all the kind comments... but it was just an educated guess based on the comment Ted made that the minimum delta is 3cm. If the minimum delta was 0cm the it could be effectively operated as a cpap.

If _SWS was still posting I'm sure he would be able to figuire out some way around that minimum.

Sound like a very interesting machine... how long will it be before dsm has taken one apart? ...I bet there's squirrels in this one.

Got one due either today or tomorrow. Hope it does housework.

Anonymous wrote:Does anyone happen to know what the "Max PS" acronym stands for? Is it "maximum pressure split"?

perhaps it's "max pressure support"

It has a min delta (the difference between IPAP and EPAP) of 3cm, so it MUST always operate as a BiPAP.

If that parameter is called "max ps" then it sounds like a limit as to how
wide of a pressure difference you will allow the machine to deliver between IPAP and EPAP. With a term like "max" you are limiting the allowable pressure split. Example: set a "max ps" of 4 cm and the EPAP/IPAP split will never be allowed to exceed that 4 cm.

If that parameter were called "min ps" instead then it would limit the machine from having an EPAP/IPAP spread of less than 3 cm. A "min ps" of 3 cm would restrict the machine to behaving as a BiLevel. However, in my way of thinking a "max ps" parameter would not at inherently restrict the machine from running with an IPAP equal to EPAP. If the machine is restricted from doing this, I would think it's a parameter or algorithmic control other than "max ps". I could be wrong!

[quote= "titrator"]There is a Max PS control that allows you to set the Delta range between 3 cm and 8cm[/quote]

Guest,

The stated min PS is 3cm. You are correct that if the min limit was 0cm then it could effectively be set-up as a non-BiLevel machine.

I'm confused. The parameter is called "max ps" the minimum setting for "max ps" is 3 cm. If you set this parameter at it's minimum value of 3 cm, then you are setting this "max ps" parameter as follows:

"A maximum pressure spread of 3 cm". Note that a maximum allowable pressure spread of 3 cm says nothing of restricting how close IPAP and EPAP may go.

You are thinking of a "max ps" pressure setting of 3 cm as if it that same 3 cm spread limit were also restricting how close IPAP and EPAP may go.

max ps = 3 restricts the maximum IPAP/EPAP spread to 3 cm
max ps = 4 restricts the maximum IPAP/EPAP spread to 4 cm
max ps = 5 restricts the maximum IPAP/EPAP spread to 5 cm
max ps = 6 restricts the maximum IPAP/EPAP spread to 6 cm
max ps = 7 restricts the maximum IPAP/EPAP spread to 7 cm
max ps = 8 restricts the maximum IPAP/EPAP spread to 8 cm

None of the above settings restrict how close to each other IPAP and EPAP are allowed to go. They each restrict the maximum allowable difference between IPAP and EPAP. Again, I could be interpreting what "max ps" means entirely wrong!

Can y'all imagine what's going to be happening when doctors write a bilevel Rx as usual... with just two pressures (IPAP/EPAP) mentioned? And the rest of this machine's workings are left to the DME to set?

I'm thinking of the occasional DMEs that have been posted about who are not even aware of the existence of a "rise time" setting in regular bi-levels. Not to mention the in-a-hurry DMEs who aren't about to work with the user long enough to get a bi-level in sync with them.

Maybe this autotitrating BiPAP will be the easiest of all BiPAPs for unknowledgeable DMEs to set up.

I'm thinking the BiPAP's autotitration algorithm will try to keep the EPAP/IPAP spread as far as "max ps" will allow for the sake of comfort. However, heavy airway closures during the end of expiration will likely force the autotitrating BiPAP to move EPAP and IPAP closer together.

The "max ps" is an important setting as a vast difference between EPAP and IPAP constitute true ventilatory "pressure support" which is undesireable in many cases.

More thoughts on a BiLevel's EPAP/IPAP delta. A traditional BiLevel has a fixed delta or pressure difference between its EPAP and IPAP. If that delta is set at 3 cm, then a traditional BiLevel will always deliver an EPAP that is exactly 3 cm less than IPAP.

Enter the autotitrating BiLevel. There is no reason for the IPAP and EPAP delta to be fixed. Rather based on sensed sleep events the EPAP/IPAP would be a "sliding" delta (based on balancing patient comfort at lower EPAP pressures against obstructive airway needs during expiration).

I suspect that if this Remstar autotitrating BiPAP relied on a fixed EPAP/IPAP spread, then this particular parameter would have been given a name other than "max ps". Rather, respoironics would have given it a name that implies fixed delta. Rather "max ps" implies an upper limit or cap to an EPAP/IPAP differential that is "sliding" based on patient needs.

Again, I sure could be wrong! Regardless this is one very interesting machine!

Ok, my normal settings are ipap 12 and epap 8....now, I want the auto to be auto..so what should the setting be? Minimum of say 6 epap and max of 14 ipap with the max "ps" set to 4 to maintain the equal 4 difference? I just got it today...guess I will run it as normal bipap tonight.. Also I guess it should be set for auto biflex-ABFE, min epap-6, max ipap 14, max ps-4 for auto mode? Also, the split night time setting screen should be? When set like that...the difference was only 2 from ipap to epap.

Sthnreb, if it were me I'd set it up to run exactly as my previous BiPAP then collect baseline data for several days. Then I'd turn auto mode on and watch for changes in my overnight sleep data.

My guess is that a setting of EPAPmin=6, IPAPmax=14, and MAXps=4 would behave as follows:

Your autoBiPAP would self-adjust, delivering between a max of 14/10 and a min of 10/6. As long as you did not experience heavy airway closures during the middle or end of expiration that 4 cm EPAP/IPAP pressure split would be maintained for the sake of comfort. However, if you experienced heavy or atypical airway closures during expiration, then the self-adjusting BiPAP would automatically move your EPAP closer to your IPAP for the sake of clearing your airway.

Can anyone volunteer to scan the clinician's manual for this machine and post it somewhere? I think many of us would love to know more about the operation of this innovative machine!