Oximetry Error in OSCAR

[WSHenry]

Hi,

I periodically run a oximetry check while on APAP. At the time of the last run, I started and stopped both the machine and oximeter at roughly the same time. When I transferred the oximetry data into OSCAR, the last one plus hour was not included. The stop time agrees when viewed in the SpO2 Assistant software s well as the stop time listed in the associated CSV file. See the attached file.

Can someone suggest what might be going on here?

[pholynyk]

Unfortunately, I can think of several things...

Fist I calculated the percentage difference in duration as 15%. This much error would likely rule out some of the possibilities.

One possible error is sampling rate; OSCAR assumes once per second. Too slow a sampling rate would create a shorter duration record. (15% is a huge rate error, not likely the problem here)
Another possibility is dropping data during the import; this is dependant on the operating system and what else it may be doing, as well as the design of the import software. Have you tried importing using Contec's SpO2 Assistant as well as OSCAR's direct import? They should report the same duration...
It is also possible there was an error during the conversion from the sample per second data imported to the time-delta format used by OSCAR's database format.

The last, which processes data in chunks, seems the most likely culprit, given the large error, and that I have seen duplicated SpO2 data occasionally. I will make a note in the Mantis issue tracker about lost and duplicated data during conversion.

[WSHenry]

Thanks for your thoughts on this. The associated oximetry CSV file shows sampling occurs every second. Also, I imported the data into OSCAR directly as well as through SpO2 Assistant, with the same results.

This was the first time I'd seen this. All prior imports into OSCAR were done without issue.