EDF files created by my ResMed CPAP device

I noticed using sleepyhead that there some detail files noted as a part of my sleep sessions, separate file for each session: Does anyone know of a file reader that will open and read these files? Preferrably a free file.

AirSense A10 AutoSet w/heated humidifier
AirFit P10 Mask

Thanks
Mike

CPAP Sessions
On Date Start End Duration
ResMed Session #1442027738
9/11/2015 23:15:39 04:05:39 04h 50m 00s
20150911_231538_PLD.edf
20150911_231538_BRP.edf
20150911_231538_SAD.edf
20150911_231535_EVE.edf
STR.edf
ResMed Session #1442045538

The edf files are European Data Format files. The wonderful free SleepyHead software can read these files and import and display the data. The SleepyHead source code is available if you want to understand more about the data.

The European Data Format (EDF) is a simple and flexible format for exchange and storage of multichannel biological and physical signals. It was developed by a few European 'medical' engineers who first met at the 1987 international Sleep Congress in Copenhagen.

I would expect that those files contain only machine readable data, I have looked at them in a simple text editor and could see nothing identifiable

In SleepHead in the file menu there is an export selection that will take the raw data and export it to a CSV (excel) file, you can then see everything in the files:

2015-09-12T03:21:51 1442049722 Pressure 9.48
2015-09-12T03:22:03 1442049722 Pressure 9.48
2015-09-12T05:21:30 1442053972 Obstructive 15
2015-09-12T03:43:43 1442053972 ClearAirway 10
2015-09-12T03:33:34 1442053972 Pressure 8.82
2015-09-12T03:33:38 1442053972 Pressure 8.84
2015-09-12T03:34:08 1442053972 Pressure 8.86

There's a "Polyman" EDF viewer program, but it's not really that easy to do much useful with it in terms of CPAP data.

Unless you have something specific to do, SleepyHead or ResScan would be the thing to use for reviewing your CPAP data.

Thanks to all who responded to my question. I appreciate the help and support from all in this group.

Mike