NEW MACHINE

[Velbor]

I have been a ResMed Vantage user. I just recently obtained a Respironics A-flex machine. There is only one reason for my new acquisition: the auto algorithms are different. One or the other MIGHT be better for MY specific breathing issues; if so, I want to know about it, and the only way is to try them both. It will take me some time to collect enough data for a fair comparison.

Meanwhile, assuming that the algorithm response will be a personal matter, how do the two machines stack up on other issues? Here's what I have found to be significant (or interesting, or annoying):

--The ResMed clock/calendar can be user-reset; the Respironics clock cannot be reset.
--The ResMed power supply is entirely self-contained; the Respironics has an external "brick".
--The ResMed detail data is resident in the machine and can be downloaded to the card at "any" time; the Respironics detail data must be loaded "live" onto the card or it is gone.
--The ResMed LCD screen is back-lit and easy to read; the Respironics screen is more basic.
--The ResMed LCD screen information gives "current session" data as well as data over time; the Respironics information is less robust.
--The ResMed machine allows entering "Clinician Menu" at any time; the Respironics only at power-up.

--The Respironics has (optionally) two nice air intake filters; the ResMed has only one rather crude one.
--The Respironics has its "flex" options in both auto and CPAP mode; the ResMed has no auto-mode pressure relief options.
--The Respironics can be set to switch automatically from CPAP to auto mode after a pre-set time; the ResMed has no such option (though admittedly few will likely have use for this).

Since I am using a stand-alone humidifier, I have nothing to say about the integrated humidifiers; there are plenty of posts about those. Also, I am not addressing the quality, utility, reliability or availability of software & smartcards; those also are discussed in many posts. Finally, I am not addressing the relative merits of the "flex" pressure relief systems which are provided.

I have heard opinions, but have seen no hard information, regarding the relative reliability and longevity of the two machines.

There are a number of other differences, but they seem mostly to come down to issues of preference which can be easily gotten over.

Strikes me as largely a toss-up. But IF the two machine algorithms come out with no clinically significant difference, I expect I will stick with the ResMed.

[Velbor]

I am posting this separately from my comment above, though in the same thread, since it is a ResMed vs. Respironics issue, but it is a question rather than a comment, and much more specific.

As I have described above, I have used the S8 Vantage with a stand-alone humidifier. On average, my humidifier puts out about 21 cc of water per hour. This figure is pretty consistent over time. (Yes, some of us are sufficiently geeky and have nothing better to do than to measure reservoir water volume at night and again in the morning.)

With the Respironics A-flex auto, using comparable machine settings, and the same humidifier (and humidifier settings) and mask, the water output has jumped significantly, to 31cc per hour. Environmental factors (room temperature & humidity) are unchanged.

The only thing I can think of that might cause this is the temperature of the air coming out of the Respironics blower being considerably higher, and thus able to pick up more water vapor as it passes through the humidifier.

Does anyone have information about blower output air temperatures? Or any other explanation of my observation? Thanks.

[ozij]

[quote="Velbor"]I am posting this separately from my comment above, though in the same thread, since it is a ResMed vs. Respironics issue, but it is a question rather than a comment, and much more specific.

As I have described above, I have used the S8 Vantage with a stand-alone humidifier. On average, my humidifier puts out about 21 cc of water per hour. This figure is pretty consistent over time. (Yes, some of us are sufficiently geeky and have nothing better to do than to measure reservoir water volume at night and again in the morning.)

With the Respironics A-flex auto, using comparable machine settings, and the same humidifier (and humidifier settings) and mask, the water output has jumped significantly, to 31cc per hour. Environmental factors (room temperature & humidity) are unchanged.

The only thing I can think of that might cause this is the temperature of the air coming out of the Respironics blower being considerably higher, and thus able to pick up more water vapor as it passes through the humidifier.

Does anyone have information about blower output air temperatures? Or any other explanation of my observation? Thanks.

[Velbor]

Thank you, ozij. I should have been more explicit. I should have written:

With the Respironics A-flex auto, using comparable machine settings, and the same STAND ALONE humidifier (and humidifier settings) and mask, the water output has jumped significantly ....

No change except for the blower engine itself.

[Slinky]

Good posts, Velbor. I hope they don't get lost in this thread.

[andy88488]

I am posting this separately from my comment above, though in the same thread, since it is a ResMed vs. Respironics issue, but it is a question rather than a comment, and much more specific.

As I have described above, I have used the S8 Vantage with a stand-alone humidifier. On average, my humidifier puts out about 21 cc of water per hour. This figure is pretty consistent over time. (Yes, some of us are sufficiently geeky and have nothing better to do than to measure reservoir water volume at night and again in the morning.)

With the Respironics A-flex auto, using comparable machine settings, and the same humidifier (and humidifier settings) and mask, the water output has jumped significantly, to 31cc per hour. Environmental factors (room temperature & humidity) are unchanged.

The only thing I can think of that might cause this is the temperature of the air coming out of the Respironics blower being considerably higher, and thus able to pick up more water vapor as it passes through the humidifier.

Does anyone have information about blower output air temperatures? Or any other explanation of my observation? Thanks.

I have no data, but when I used to use my S8 Compact, I felt that the air came out cold, which made it more difficult for me to go to sleep. When I switched to the Respironics, I no longer feel that way. That is using both machines with their attached Humidifiers.

[Snoredog]

who told you the S8 was a Cadillac? When was the Cadillac made down under? Just because that moron company decides to rip off Americans by intentionally overpricing it by a factor of 2, doesn't mean it is a Cadillac.

I just can't resist commenting on that.

Firstly, Resmeds actually cost a lot more in Australia than they do in the US. If they were overpricing by a factor of two they'd be making more than $100 million profit on a turnover of $200 million instead of which they only posted a profit of just under $27 million, which is a fair profit in my opinion. Oh, and they are actually made in the states these days aren't they?

Secondly, a Cadillac isn't something to aspire to. Nor for that matter are any cars made down under. If you want a saloon, it's got to be German, and a sports car must be Italian. If you want to learn to be a motor mechanic, you can just buy British. I can't wait for Toyota to start making CPAP machines, then we'll have some price competition for the cartel.

It's obvious from SD's repeated vehement comments that he got fired from Resmed. Nothing else could cause someone to hate the company as passionately as he does...

Colin

with his tongue firmly in his cheek

[Slinky]

SnoreDog, dear heart, WHERE is your proof of Resmed's having voided ANY warranties?

[jomac30]

THANKS TO ALL
I think all this info will be helpful in making my decision.

[kennethryan]

Does anyone have information about blower output air temperatures? Or any other explanation of my observation?

This is just a guess (take with lots of salt), but here goes:

According to the Resmed/Respironics comparison study quoted in another post, the M series tends to run at a lower pressure than the S8. Lower pressure also means a lower flow rate (given the same mask, etc.). Maybe the lower flow rate gives the air more time to warm up and pick up water while in the humidifier than the higher flow S8.

A possible experiment would be to put both machines in CPAP mode at the same pressure and then compare.

It's also possible if the M series is physically smaller thus a smaller blower motor that the motor runs hotter than the S8. If they design it so that the airflow helps cool the motor then it would explain the warmer output temperature and thus better humidity pickup over the S8.

(...)

OK I just looked up some numbers. In the S8 clinical manual, they list power consumption of 11.6W @ 10cm, 15.9W @ 15cm. I don't see a similar table in the M series website page, but looking up the battery pack specs it says the 14.4Ah battery lasts an estimated 20 hours @ 12cm. That means the M Series is running about 8.6W @ 12cm. Since the biggest power consumer in these units should be the blower motor, the possibility of the motor running warmer in the M series is an unlikely explanation for the apparent temperature difference. Oh well. The M series still could be cooling the motor via patient air while the S8 cools it some other way therefore accounting for an air warming effect. I've never looked inside my machine to see how it's done. (Another ~8mo on the warranty, then I'll look. I'm a geek too, as if you couldn't tell by now. )

[ozij]

Thank you, ozij. I should have been more explicit. I should have written:

With the Respironics A-flex auto, using comparable machine settings, and the same STAND ALONE humidifier (and humidifier settings) and mask, the water output has jumped significantly ....

No change except for the blower engine itself.

[rested gal]

jomac, I've used Respironics, Puritan Bennett, and resmed autopaps.

By far the most comfortable to use (for me) is the Respironics REMstar Auto with A-flex.

The next most comfortable brand (again, for me) - the Puritan Bennett 420E, which, while it does not have an exhalation relief feature per se, there's something about the way the motor's fan blades "give" or something, that makes the beginning of exhalation easier to breathe out against (for me) than trying to breathe out against the resmed autopap. There is no exhalation pressure relief at all in the Vantage when it is operated in "auto" mode.

As far as "treatment" goes, I got equally good treatment from all three brands, despite the fact that the resmed machines always toted up about twice as high an AHI than the others. As far as I was concerned, that difference seemed to be just a "reporting" difference and didn't seem to affect the way I felt at all. But there was a very noticeable, pleasant difference in the ease of breathing out while using the REMstar with A-flex. Feels much more like natural breathing.

[gasp]

The S8 Vantage does NOT have exhale relief in APAP mode......the REMstar Autos DO.

The REMstar M Series Auto w/A-Flex is the top-of-the-line Auto/APAP as it has more features and modes of therapy than all the rest.

Den (not going to do car comparisons.....as I drove both Chevys and Fords)

I hear an echo again !

Maybe the "some" who say the Vantage is a Cadillac were refering to a 50's model with no AC or power steering?

[Wulfman]

The S8 Vantage does NOT have exhale relief in APAP mode......the REMstar Autos DO.

The REMstar M Series Auto w/A-Flex is the top-of-the-line Auto/APAP as it has more features and modes of therapy than all the rest.

Den (not going to do car comparisons.....as I drove both Chevys and Fords)

I hear an echo again !

Maybe the "some" who say the Vantage is a Cadillac were refering to a 50's model with no AC or power steering?

[Velbor]

So much for my theory (see above post regarding humidifier output) that the Respironics auto runs "hotter" than the ResMed auto. Today, with a few lengths of short tubing, a ventilator circuit Y connector with ports, a lab grade mercury bulb thermometer, a thermocouple with a digital multimeter, and some chewing gum to plug measurement port leaks, I ran the numbers.

Both a ResMed S8 Vantage auto, and then a Respironics M-Series (A-flex) auto, were set to run in straight CPAP mode (no pressure relief) at 10cm water. (My test setup included a water manometer which indicated that both machines were maintaining an 11cm pressure.) I jury-rigged the exhaust vent of my ResMed Activa mask to provide appropriate airflow (specified venting @ 10cm = ~33 L/m).

With my house thermostat set at 72 F, ambient temperature was measured at the start and end of the experiment. I checked each machine's output air temperature using the two temperature sensors, located about 12" from the machine, at 15 minute intervals; both machines achieved a stable temperature at 30 and 45 minutes. Here are the results, in degrees F:

....................................Ambient..........ResMed.......Respironics
Mercury Thermometer.........77..................89................84
Thermocouple.....................71..................83................77

Thus the ResMed machine air output was 12 degrees F over ambient, while the Respironics machine ran at 6 - 7 degrees F over ambient. I am forced to conclude that my Respironics machine is, literally, "cooler"!

The temperature differences are consistent with kennethryan's observations, posted above, regarding machine wattages.

This temperature difference does not necessarily make one machine "better" or "worse" than the other; they are presumably part of each machine's design specifications. The difference may or may not be desirable, based on each user's situation, though it is unlikely to be of any relevance.

I would point out also that the manuals for BOTH machine's make reference to a possible 11 degree F air temperature rise above ambient:

Do not use this device if the room temperature is warmer than 95° F (35° C). If the device is used at room temperatures warmer than 95° F (35° C), the temperature of the airflow may exceed 106° F (41° C). This could cause irritation or injury to your airway.

The air flow for breathing produced by this device can be as much as 11oF (6oC) higher than the temperature of the room. Caution should be exercised if the room temperature is warmer than 90oF (32oC).

At the end of the day, I have less understanding than ever of the reason for the change in my humidifier output as previously described. But I do have the satisfaction of having done some science.