I need help with my new Aircurve 10 ASV

[Jeffo1]

Jeff, Resmed and Respironics ASV machines operate in ways that feel different to users, and we have seen people respond better to one machine than the other, but it's not something you could predict based on a single night sleep study. What was the exact pressure prescription by your doctor?

All pressure settings are easily accessible by pressing the control knob and home button at the same time to enter the clinician settings. You are not quite ready for that until you fully understand what you want to accomplish and why. Once you have over 8 posts you will be able to post data that may help us to help you more accurately. A max EPAP is quite high, and I doubt you need to adjust that; however if you are experiencing a lot of obstructive events (snoring, flow limitation, hypopnea, and OA), then you would need to increase the minimum EPAP. We need a little more detail on your results to advise.

Hi!

Thanks a lot!

I'm awaiting the delivery of a Respironics Auto ASV, which, hopefully, will shed some light on the apnea events. ResMed Air data for the Air Curve 10 ASV does not differentiate between types of events. I can see how valuable that information can be, and so I'm moving to SH for my sleep data.

To be continued....

Best,

Jeffo1

[shewhorn]

As I understand it, the AirCurve doesn't differentiate between events, specifically Centrals and Obstructives, because the algorithm is working so fast that it effectively eliminates them. With the AirSense machines, if an Obstructive or Central even occurs, it's analyzing the data after the fact to determine what happened. With the AirCurve... it's not going to wait while you're not breathing for 10+ seconds, it's just going to react almost instantly. When the algorithm expects and inspiration but doesn't see one, it's immediately going to ramp up the pressure until it sees airflow again. As a result, Central and Obstructive events don't have an opportunity to really happen.

I'm sure someone will correct me if my understanding is wrong. That said, if this is true, I don't think an ASV machine by a different manufacturer will be any different due to the nature of how the ASV algorithms need to work in order to accomplish their goal (but I could be wrong).

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It should be noted... if you put the AirCurve into CPAP or BIPAP mode, it will report CA and OSA but... that's kind of like using a bunker buster to kill a fly.

[palerider]

As I understand it, the AirCurve doesn't differentiate between events, specifically Centrals and Obstructives, because the algorithm is working so fast that it effectively eliminates them. With the AirSense machines, if an Obstructive or Central even occurs, it's analyzing the data after the fact to determine what happened. With the AirCurve... it's not going to wait while you're not breathing for 10+ seconds, it's just going to react almost instantly. When the algorithm expects and inspiration but doesn't see one, it's immediately going to ramp up the pressure until it sees airflow again. As a result, Central and Obstructive events don't have an opportunity to really happen.

I'm sure someone will correct me if my understanding is wrong. That said, if this is true, I don't think an ASV machine by a different manufacturer will be any different due to the nature of how the ASV algorithms need to work in order to accomplish their goal (but I could be wrong).

---

It should be noted... if you put the AirCurve into CPAP or BIPAP mode, it will report CA and OSA but... that's kind of like using a bunker buster to kill a fly.

the resmed asv doesn't differentiate between different types of apnea, true, from there on out, remove "obstructive" from what you said, and you're correct. the machine can't prevent obstructive apneas, it reports them as UA.

different brands of machines behave differently.

also, I don't believe that resmed machines will perform FOT in cpap mode, and they have no plain bilevel mode.

[richb]

the resmed asv doesn't differentiate between different types of apnea, true, from there on out, remove "obstructive" from what you said, and you're correct. the machine can't prevent obstructive apneas, it reports them as UA.

different brands of machines behave differently.

also, I don't believe that resmed machines will perform FOT in cpap mode, and they have no plain bilevel mode.

The EPAP and PS settings are designed to treat Obstructive events in the ResMed ASV machine. Some Obstructive events might break through and are then reported as UA.

Rich

[DeepBreathing]

The EPAP and PS settings are designed to treat Obstructive events in the ResMed ASV machine. Some Obstructive events might break through and are then reported as UA.

I think it's a bit more complicated than that. Another member was good enough to give me a very detailed explanation, which I will read and absorb tomorrow (day off). But in general terms, the Resmed ASV will respond to any decrease in flow by raising the pressure support and hence the IPAP is raised. It doesn't differentiate between an obstructive or central apnea. However if you're experiencing a central apnea the increased IPAP will keep you breathing right through the event. In fact the Resmed literature states that their ASV eliminates central apneas and any events which are recorded are obstructive in nature.

In my own experience, the pressure support goes up and down all the time on a breath-by-breath basis, while EPAP is adjusted more gradually in response to snoring, flow limitation, hypopnea and apneas.

Having used both machines I can say there is a very real difference in the "feel". The Philips never got my AHI below about 15 and always felt like it was forcing my breathing. The Resmed has a much more gentle feel and my AHI is always <2.0, mostly <1.0. I always recommend that people try both machines if they can, as they are very different in feel and operation. There is a very good article on the Resmed and Philips algorithms here: http://journal.publications.chestnet.org...id=1891790

[richb]

The EPAP and PS settings are designed to treat Obstructive events in the ResMed ASV machine. Some Obstructive events might break through and are then reported as UA.

I think it's a bit more complicated than that. Another member was good enough to give me a very detailed explanation, which I will read and absorb tomorrow (day off). But in general terms, the Resmed ASV will respond to any decrease in flow by raising the pressure support and hence the IPAP is raised. It doesn't differentiate between an obstructive or central apnea. However if you're experiencing a central apnea the increased IPAP will keep you breathing right through the event. In fact the Resmed literature states that their ASV eliminates central apneas and any events which are recorded are obstructive in nature.

In my own experience, the pressure support goes up and down all the time on a breath-by-breath basis, while EPAP is adjusted more gradually in response to snoring, flow limitation, hypopnea and apneas.

Having used both machines I can say there is a very real difference in the "feel". The Philips never got my AHI below about 15 and always felt like it was forcing my breathing. The Resmed has a much more gentle feel and my AHI is always <2.0, mostly <1.0. I always recommend that people try both machines if they can, as they are very different in feel and operation. There is a very good article on the Resmed and Philips algorithms here: http://journal.publications.chestnet.org...id=1891790

I probably should have qualified my EPAP settings. My EPAP settings are fixed. They do not adjust. I don't have significant Obstructive Apnea and therefore my EPAP settings are just fine at fixed settings. Higher pressures just convert my Periodic Breathing to full blown Centrals. I do have some short periods of normal breathing during the night so I guess my settings are good.

Rich