Dreamstation 2 cannot keep time?

[cpap@aidtopia.com]

For a few years, I had a Dreamstation. The value reported for "therapy time" always seemed to be consistent with the nightstand clock. If I started the machine at 11 pm and shut it off at 6 am when I got up the following morning, it would report 7 hours. No surprises. If I napped for another hour in the morning, that would be added to the previous night's time. If I napped for another hour in the afternoon, that would count toward the following night. I concluded the software used noon as the cutoff for therapy hours. (At least, what it thought was local noon. I'm in the Pacific Time Zone, but--for a long time--my machine thought I was in the Central Time Zone.)

Philips eventually replaced my Dreamstation with a Dreamstation 2 because of the recall. At first, the "therapy hours" reported by the new machine was often correct, but occasionally (maybe once every few weeks) it seemed to shortchange me 1 hour. Twice, I noticed this happened at the end of a month. For example, if I turned on the machine at 11 pm on the last day of the month, and slept until 6 am the next morning, it would report 6 hours instead of 7. I hypothesized that the usual noon cutoff was instead midnight at month boundaries. But I was unable to collect enough data to test it.

Shortly after I developed that hypothesis, something changed. The reported therapy time is now routinely wrong, most days it reports at least an hour less than the amount of time I used the machine. And the discrepancy seems to be trending larger. I began to wonder whether there had been an over-the-air firmware update that changed how it tracks therapy time.

I mentioned this to my doctor, but he shrugged it off. The surveillance data reported to him by the machine shows that I'm sufficiently compliant, my mask fit is "100%", and my AHI is low when I'm using the machine, so he's satisfied.

Does anyone have any insight on what might be going on? I cannot seem to find any more information. Was there a firmware upgrade? It there some subtlety to how it counts therapy time?

[chunkyfrog]

Respironics replacements!
What can go wrong--will go wrong, in newer and screwier ways.
Always using Resmed machines------PRICELESS!

[ChicagoGranny]

I mentioned this to my doctor, but he shrugged it off.

As he should. (Maybe you should.)

What does OSCAR say?

Welcome to the forum!

[chunkyfrog]

If you can prove it, perhaps you should file a complaint with somebody.
But I have no clue who that would be.
There should be a government agency protecting us from faulty medical devices.

[D.H.]

Ok, you're reporting a discrepancy of one hour or more when you wake up in the morning almost every morning.

Have you gone back and checked prior days (to see if the shortfall has been corrected)?

If there does appear to be a correction later, there are two possible reasons for this.

The first is that the machine is simply slow in uploading the data.

The second is that the cutoff time is not set correctly. Most CPAP machines consider a day to be from noon-to-noon, rather than midnight-to-midnight. If you're cuttof is at a strange time, it's possible that some of your sleep time is recorded in the previous or following day. If this is the case, you should show the correct number of average hours over time, even if stuff is recorded for the wrong day.

[chunkyfrog]

It would be nice if the clock could be set by the user--like in my Resmed.

[Drewster]

I'm having a very similar issue with my Resmed AirCurve 10 ST bipap machine. The usage time is continually off by an hour or so, so does not correct from day to day. How can I check/set the clock/cutoff time on my Resmed AirCurve 10? How can my AHI be correct if the usage time is incorrect?

[chunkyfrog]

I'm having a very similar issue with my Resmed AirCurve 10 ST bipap machine. The usage time is continually off by an hour or so, so does not correct from day to day. How can I check/set the clock/cutoff time on my Resmed AirCurve 10? How can my AHI be correct if the usage time is incorrect?

The screen shows both therapy time and run time--do not be confused.
Usage time will not match run time--ever.
Run time includes ramp and cool-down, which are not considered therapy,
and can go for up to an hour or so more than "usage".