Best BiPap machine for new user.

[AndrewMT]

I recently finished my second sleep study (titration study) to determine my optimum pressure. I guess from the study my doctors determined that I was intolerant to constant pressure, and the company that will provide and setup my BiPap machine has ordered the Philips Respironics System 1 BiPap, model DS650h.

Now, I had been doing some research into BiPap machines and was interested in the S9 VPAP™ Auto BiLevel Machine, which is also an option from the company providing my BiPap. It also seems that there is a newer Respironics model, the DS750. Does anyone know the difference between the DS650 and the DS750 (google was no help with this), and would anyone recommend the S9 over the System 1?

Thanks in advance for your help!

[cflame1]

a DS650 is a Bipap Pro... continually 1 set of pressures (1 for inhale and 1 for exhale)

a DS750 is a Bipap Auto... which will move within a certain set of parameters. It can also be a CPAP and a set pressure BiPAP. So essentially 3 machines in 1.

[robysue]

I recently finished my second sleep study (titration study) to determine my optimum pressure. I guess from the study my doctors determined that I was intolerant to constant pressure, and the company that will provide and setup my BiPap machine has ordered the Philips Respironics System 1 BiPap, model DS650h.

Now, I had been doing some research into BiPap machines and was interested in the S9 VPAP™ Auto BiLevel Machine, which is also an option from the company providing my BiPap. It also seems that there is a newer Respironics model, the DS750. Does anyone know the difference between the DS650 and the DS750 (google was no help with this), and would anyone recommend the S9 over the System 1?

Thanks in advance for your help!

Both the Resmed S9 VPAP Auto and the PR System One BiPAP Auto are nice machines. There are differences between them.

The three big categories of differences, in my humble opinion are:

• The comfort features
• The on-board data and software choices
• The auto algorithm itself

Which machine to chose may depend on your own needs and preferences in each of these categories.

The Comfort Features
The S9 has the ClimateLine heated hose as an option. And its anti-rainout system is based on the ClimateLine hose. The System One's anti-rainout is based in how the humidifier takes the room's relative humidity and temperature into account in how hot it heats the water and how much water it allows to evaporate into the air going into the tube.

The System One has Bi-Flex as an exhalation relief system. Bi-Flex will provide a small bit of additional pressure drop beyond that provided by simply going from the IPAP to EPAP settings. In other words, if IPAP = 15 and EPAP = 10, at the start of the exhalation, the pressure will actually drop a bit below 10 cm and then the machine will increase the pressure back up to 10cm before the exhalation is complete. I believe the S9 VPAP does not have any additional pressure relief: The transition between IPAP and EPAP and back to IPAP is already a modified version of the EPR system in the S9 Elite/AutoSet. What I mean by "modified" is that in the S9 VPAP, the pressure drop at the beginning of the exhale obviously not limited to a max of 3 cm. And there is a very slight difference between how and when the VPAP and the Elite/AutoSet increase pressure back up at the end of the exhale or start of the inhale. There's an very old thread that gives a lot of details about this. You can read it by clicking here. (The thread is still there, but the wonderful images by -SWS on pages 2, 3, and 4 seem to have disappeared. )

On-board data and software choices
The on-board data on the System One is very, very limited. The AHI is only 7 and 30 day rolling averages and is not broken down at all by event type. And the System One's on-screen "Percent time spent in Large Leak" data are virtually meaningless: Not only is 1% of seven nights of data a very long time, but also PR doesn't seem to define or describe what constitutes a Large Leak anywhere. And there's the annoying fact that the System One updates its data at noon Greenwich Meridian Time. And that you can't change this. And that you can't change the clock setting---even in the clinical menu.

The on-board data on the S9 VPAP is excellent: You get nightly, weekly, and 30 AHI numbers broken down by type of event. You get 95% unintentional leak rate figures. And there's a mask-fit feature that may be useful. The overnight data is available within a minute of turning the machine off. But you do have to view the overnight data before noon local time. And you can set the clock through the clinician's menu.

As for the software: SleepyHead can be used for either of the machines, although it's still a bit buggy with the S9 VPAP Auto if I understand correctly. The newest version of ResScan should work with the S9 VPAP. Encore Viewer and Encore Pro will both work with the System One BiPAP Auto. Both machines record the following data on the SD cards:

• AHI broken down by types
• time of each event
• leak rate data
• wave form data---i.e. you can see each breath you took all night long
• some form of flow limitation data
• some form of snoring data
• pressure setting data

In addition to the above data, the S9 also records information about minute ventilation and respiratory rate. In addition to the above information, the System One records RERAs and periodic breathing (Cheny-Stokes breathing).

The leak data on the System One is total leak---i.e. it includes the expected leak built into the mask. The S9 reports unintentional leaks---i.e. the S9 subtracts off the expected leak rate for the type mask you are using at the pressure you are using and reports any excess leak.

The System One "flags" flow limitations and snoring as discrete events; the S9 provides a continuous graph indicating the amount of flow limitation and the severity of the snoring as functions of time. Note that the System One does record enough snore data for SleepyHead to provide a snore graph as well as the tick marks. The Flow Limitations are only recorded on the System One BiPAP Auto when it is running in Auto mode.

The Auto Algorithms
The Auto Algorithms used by the Resmed S9 VPAP and the PR System One BiPAP auto are NOT the same. And the differences may be important to you in the sense of how it feels to use the machine all night long. And which algorithm would feel best to you may be hard to predict.

That said, here is my understanding of the differences between the two Auto algorithms:

Both the Resmed S9 VPAP Auto and the PR S1 BiPAP Auto have algorithms that automatically adjust the IPAP and EPAP pressures in response to the various events detected by the machine. But the two companies have taken quite different approaches in their algorithms. Informally this difference can be described as follows:

• The Resmed S9 VPAP adjusts BOTH the EPAP and IPAP by the same amount in response to OAs, hypopneas, snoring, and flow limitations. Like the S9 AutoSet, the VPAP tends to respond quickly to clusters of events and then slowly reduces both pressures back down at the same rate until more events occur.
• The PR S1 BiPAP Auto adjusts EPAP and IPAP independently of each other: EPAP is increased in response to OAs and snoring, and IPAP Is increased in response to hypopneas, flow limitations, and RERAs. In addition to these things, the PR S1 also uses the same "hunt and peck" algorithm that the PR S1 Auto uses to test whether the shape of the wave flow data improves with a slight increase in pressure. The hunt and peck algorithm is only applied to the IPAP pressure for increasing pressure. After events that trigger an increase in IPAP or EPAP are resolved, the S1 does a reverse hunt and peck to find out how far it can lower the pressure: As long as the flow wave remains stable, the PR keeps lowering the appropriate pressure, but if the flow wave becomes more ragged, the S1 will raise that pressure back up to the last level where the flow wave was stable

To make the some of the differences between the two machines' auto algorithms clearer, we need to introduce a setting that only Auto Bi-level PAP machines have---the PS (pressure support setting). Loosely PS is the difference between IPAP and EPAP and the value of the PS setting affects the way the EPAP and IPAP pressures are adjusted. The way PS is implemented on the S1 and the VPAP is quite different however:

• On the S1 BiPAP Auto, the PS setting is the maximum allowable value for IPAP - EPAP. And the minimum value the S1 will allow for IPAP - EPAP is 2. The upshot of this is that whenever 2 < IPAP - EPAP < PS, the IPAP and the EPAP are allowed to vary independently of each other. But when IPAP - EPAP = 2 or IPAP - EPAP = PS, there are some constraints on how the pressures are increased or decreased. In other words:
  
  • When 2 < IPAP - EPAP < PS:
    • If the IPAP needs to be increased, only the IPAP will be increased, the EPAP stays the same.
    • If the IPAP needs to be decreased, only the IPAP will be decreased, the EPAP stays the same.
    • If the EPAP needs to be increased, only the EPAP will be increased, the IPAP stays the same.
    • If the EPAP needs to be decreased, only the EPAP will be decreased, the EPAP stays the same.
  • When IPAP - EPAP = PS:
    • if the IPAP needs to be increased, then both IPAP and EPAP will increase at the same rate.
    • If the IPAP needs to be decreased, only the IPAP will be decreased, the EPAP stays the same.
    • If the EPAP needs to be increased, only the EPAP will be increased, the IPAP stays the same.
    • if the EPAP needs to be decreased, then both IPAP and EPAP will decrease at the same rate
  • When IPAP - EPAP = 2:
    • If the IPAP needs to be increased, only the IPAP will be increased, the EPAP stays the same.
    • if the IPAP needs to be decreased, then both IPAP and EPAP will decrease at the same rate.
    • if the EPAP needs to be increased, then both IPAP and EPAP will increase at the same rate.
    • If the EPAP needs to be decreased, only the EPAP will be decreased, the EPAP stays the same.
  • And at the start of the night, EPAP = min EPAP and IPAP =min EPAP + 2.
• On the VPAP, the PS setting is the fixed value for IPAP - EPAP. Hence IPAP and EPAP are always increased together on the VPAP. (And that's why the ResScan reports for VPAP mahcines can show the pressure info with only one curve.) At the start of the night EPAP = min EPAP and IPAP = min EPAP + PS.

Of course the big questions are: Which system is more effective? and Which system is more comfortable? As a mere patient, I haven't the foggiest if one of these systems is inherently better at treating apnea. And obviously both machines have been run through the full range of efficacy testing required by the government. But it's easy to believe that some folks might respond better to one of the two algorithms than the other.

In my case, I am rather glad (in retrospect) that I was forced to get the System One because the S9 VPAP Auto was not yet on the market at the time I was switched to bi-level. The reason I say this? It's because of my own patterns of pressure increases. On my S1, the most common reason either the IPAP or EPAP is increased is the machine detecting flow limitations and the hunt-and-peck algorithm that picks up very subtle flow limitations. Both of these only increase my IPAP. And so I start the night off at 6/4, but tend to spend significant chunks of time at 7/4 and 8/4 most nights. My EPAP rarely goes above 5cm these days. Since my old S9 AutoSet also increased pressure in response to flow limitations, I would strongly suspect that if I were using a S9 AutoSet, my EPAP would not remain at 4cm for most of the night and my guess is that it would regularly be above 5cm. And for me, aerophagia problems were a major reason for trying biPAP, and it's keeping that EPAP as low as possible that helps with the aerophagia problems. (Those rare nights I snore enough to have the machine increase my EPAP to 6cm are strongly correlated to my worst aerophagia issues.)

[AndrewMT]

Thank you for that fantastic response to my questions, robysue. I reviewed the thread you mentioned and am currently poring over your blog.

Unfortunately, I am now even less sure of which product I would prefer. The Auto features on these machines seem like they would come in handy, particularly for home titration studies. Regardless of which machine I get, I will try to push for one that has an APAP mode.

The data the D750 collects seems rather vague and non-specific compared to the S9, almost to the point of uselessness. I love the idea of being able to see nightly data from the S9. I do agree with your blog article "Who do Resmed and PR think the customers are?" and hopefully the manufacturers will start to get the message.

Judging from yours and other replies on that other thread, EPR sounds like something I would also find intolerable. If I can turn EPR off, however, it seems like the S9 VPAP would perform like a "normal" BiLevel machine. If that is the case, I might go for the S9.

[cflame1]

EPR and BiFlex can both be turned off.

Honestly I'd go with the bipap/vpap auto for the flexibility... either the PR S1 or the S9. It'll allow you to check your pressure periodically by running it on auto if you don't do it all the time.

[robysue]

T
The data the D750 collects seems rather vague and non-specific compared to the S9, almost to the point of uselessness. I love the idea of being able to see nightly data from the S9.

There's nothing vague or non-specific about the data recorded by the System One. It's just that you need a computer to see it.

In other words, with SleepyHead or Encore Viewer or Encore Pro, you get to see:

• The full AHI data, including break down of events by type. The OAI, the CAI, and the HI are all there---both in the detailed data for the day and in the summary graphs over time.
• The rough time of night each event happened (in Encore Viewer) and the actual time of each event (in Sleepy Head and Encore Pro)
• Snore data, flow limitation data, and RERA data presented in the same way the apnea and hypopnea data are displayed.
• Full leak data, but, alas, no well-defined definition on what actually constitutes a "Large leak" that's big enough and long enough to adversely affect therapy.
• Full wave flow data (SleeyHead and EncorePro). In SleepyHead you have the ability to zoom in on any chunk of the wave form as close as you like---just like in ResScan.

I do agree with your blog article "Who do Resmed and PR think the customers are?" and hopefully the manufacturers will start to get the message.

Thanks for the complement

[rested gal]

Either of the two manufacturers' bilevel (and bilevel auto) machines might very well suit you equally well, Andrew. I do fine on either manufacturer's bilevel (and bilevel auto) machines.

It would be great (but easier said than done) to trial more than one -- ResMed's S9 VPAP (or S9 VPAP Auto) and Philips Respironics System One BiPAP Pro (or BiPAP Auto.) The ones with "auto" tacked onto the name go about their bilevel autotitrating quite differently from each other.

If I were not able to try both brands... just had to "hope" the first one I was given would work comfortably and effectively for me, I'd choose ResMed. Preferably the S9 VPAP Auto since, as cflame1 pointed out, any bilevel auto is like having more than one machine. A bilevel auto can be used as a plain bilevel machine, or as an autotitrating bilevel, or as a "CPAP" if both IPAP/EPAP pressures are set to the same pressure. The ResMed VPAP Auto can even be operated just as an "autopap" -- an additional way to use that particular machine. Like having four machines in one.

[Perrybucsdad]

The data the D750 collects seems rather vague and non-specific compared to the S9, almost to the point of uselessness. I love the idea of being able to see nightly data from the S9. I do agree with your blog article "Who do Resmed and PR think the customers are?" and hopefully the manufacturers will start to get the message.

I have the S9 Autoset (not the Bi-Pap) and love the machine, but I can honestly tell you I never look at the data on the machine. I always go to the computer as it is just easier to see and it tells so much more than just the raw number.

That being said, it was one of the major selling points for me when I purchased the S9. I sometimes wonder if I would be better off though on the PR system and wish I would have been able to try each unit a month before having to make a decision.