OSCAR + Devilbiss DV64 questions

[Cuppa]

Hi I have two questions regarding use of the Devilbiss DV64 CPAP with OSCAR. 

One has to do with how flow limitations are represented & the other to do with missing data.

1. Missing data. I just uploaded the last 5 nights of data from the machine’s SD card to OSCAR. The first 5 nights uploaded fine, but last nights data was not there at all. (I re-tried several times).  The front page of OSCAR tells me I last used the machine night before last. Particularly annoying as the screen on my CPAP told me I had had my best AHI score in a while last night! The SD card had been in throughout the 5 night period. 

In the past when I uploaded about a years worth of data in one go, a consecutive period of several months was absent, but this was back when OSCAR was not fully compliant with the DV64 so I put it down to that back then.

Now the DV64 is supposed to be fully compliant with OSCAR & in recent times I have done several uploads & they have been OK ... until this morning. 

Could anyone who uses a Devilbiss DV64 CPAP with OSCAR comment  regarding whether or not they have experienced missing data like this please. 

If need be I could probably copy the SD Card & send it to someone with the ability to read it to see whether or not last nights data is there, or was simply not recorded if anyone is willing to look at it for me. 

I have wondered if the SD Card might be failing, but I’m guessing if that were this the case missing data would probably be be far more random rather than for defined days?? 

2. Flow limitation representation on OSCAR. 

People talk of flow limitations being represented on a scale of 0 to 1. Screenshots in the OSCAR Wiki show a scale of 0 to 1 

   

However on my OSCAR (v1.4) the flow limitation is shown on a scale of 0 to 3.

   

Even though the little yellow ‘pop up explanation’ (when hovering cursor over flow limitation) says ‘Graph showhing severity of limitations - Severity 0-1.”

I don’t know how to interpret this. Either I am suffering terrible flow limitations even when my AHI is low, or the data from the Devilbiss DV64 is not fully compliant with OSCAR. If you look at the following flow limitation for an ‘average night’ (for me) when my AHI was reported as 2.68 you can see why I am both confused (& a little concerned)

   

Thanks, I will appreciate any insight to these anomalies anyone can offer.  

Cuppa.

[Crimson Nape]

The Flow Limit range of 0-1 is a Resmed thing. While the Philips doesn't have a graph for this parameter, I've noticed that it will list a value higher than 1 in the statistics side of the Daily screen for its Flow Limits.

- Red

[Cuppa]

Thanks Red. 
For anyone else checking in the future I have worked out that flow limitation is only shown as 0, 1, 2, or 3 and flow limitation events are only flagged when on 3. 

As far as missing data goes ,it is far more patchy than I had thought. In the records I uploaded for Jan '22 to present  only the records since 28th October have sufficient data to be meaningful. eg. Until 28/10/22 there are no flow rate graphs & often far more than that missing, sometimes only compliance hours showing. 

Since 28th October all the graphs have been present (including the missing night I referred to previously which uploaded this morning, 2 days later - must be a clock thing - cannot upload last night's data in the morning - but can 24 hours later - strange). 

Unless the 28th October 2022 was the date when OSCAR 'officially' finally became fully compatible with the Devilbiss DV64 then I think it fair to say that listing OSCAR & the DV64 machines as fully compatible was overly optimistic.

A shame, because even though Devilbiss have now stepped away from manufacturing these  machines, I still have a brand new one ready to put into use , when the current one dies. Right now I am still not 100% trusting in the 'Fully Supported' declaration - things have just been too patchy to have that sort of confidence yet, and with the machines no longer being made I cannot see any further work being done within OSCAR for them. I'll keep my fingers crossed that the useful records as from the past few weeks will continue. 

   

If someone can tell me when The Devilbiss DV64 was determined to be 'Full Supported' - I'd really like to know.  I am hoping it was just a few weeks ago - that would give me confidence, but I have an awful suspicion that it was long before that.

[Crimson Nape]

Color me silly, but have you tried using a different SD card? I'm just thinking about all the possibilities that may play a role in your problem.

- Red

[Cuppa]

Color me silly, but have you tried using a different SD card?  I'm just thinking about all the possibilities that may play a role in your problem.

- Red

Not silly at all, I have wondered about that, (it has been in use for over 5 years since the machine was new), but I'm not sure how to do it. 

Can I just put any SD card into the machine, or does it need a special format + Devilbiss file structure adding to it first?  

If so are there details on these requirements I can access anywhere?

EDIT: Aha, sussed it. Just format to MS-DOS (FAT) on my Mac & stick it the CPAP machine & wait whilst it does its thing - Remove & check & the Devilbiss file structure is all there. Will see how it goes tonight.  Fingers crossed. I so hope this works - if OSCAR & DV64 work together, & the O2 Ring I've mail ordered too, I'll be a very happy man. 

Thank you

[Cuppa]

Hi Red & others.
A brief report & another OSCAR question.

First up two days ago I installed the new SD card into my machine  & have since used the machine for two nights.

It appears to be recording ok, but there is an anomaly. 

First morning the machine screen said AHI 3.00 ...... On uploading the data to OSCAR it said AHI 17.6!  After a few moments 'panic' I realised that only the first 20 minutes of the night had been recorded. (It showed 4 hypopneas  but I was not concerned as I had been awake during that time & probably coughed, yawned or similar). At the 20 minute mark I had switched off the machine & left bed to visit the bathroom. Switched the machine back on but in the morning there was only that first 20 minutes data to upload.

Last night I didn't get up during the night at all after turning on the CPAP machine.  At just after mid-day today I uploaded the data to OSCAR. To my surprise it uploaded data for the rest of the previous night following the 'bathroom break' after the initial 20 minutes - showing my AHI as 3.03 so matched what the machine's screen had told me yesterday morning. (The screen only does AHI in increments of 0.25) . However no data at all for last night!

I feel reasonably confident that last night's data is still in the machine & that if I leave it until tonight or perhaps tomorrow I will get it out & into OSCAR.

Both nights I was in bed by around 9pm our time here in Australia (AEST) ......& awake & machine turned off by around 5:30am to 6 am the following morning.

In the past (with OSCAR 1.3 & same CPAP machine), if I got up in the night, switching off the machine, it would give data for the whole night - showing a gap for the time I had been up & the machine off.

Now using OSCAR 1.4 , very recently updated.

So it looks to me that there may be timezone issue (??) & I suppose, as nothing else has changed, that it is in OSCAR, but I haven't been able to find anywhere in OSCAR settings to alter the timezone. Am I missing the obvious, or is there no way to change it? My computer & CPAP machine times are in sync with each other & OSCAR gives the correct local time for my last upload (12.02 today).   Just no data for last night ...... yet.

Had my first night with the O2 ring last night, but would like to sort this anomaly out if I can, before adding in Oximetry data.

Any suggestions please?

[Cuppa]

I now have a bit more info, but will post on the software support section to see if anyone can help.