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+--- Thread: Where is Resmed Inspiration/Expiration Time in BRP or PLD file (/Thread-Where-is-Resmed-Inspiration-Expiration-Time-in-BRP-or-PLD-file)
Where is Resmed Inspiration/Expiration Time in BRP or PLD file - JustaHoseHead - 02-27-2021
I am trying to read the edf files for my Resmed to look at the inspiration and expiration times outside of OSCAR or Sleepyhead to calculate dutycycle type numbers. I have edf browsers and can read the headers, and data, but nothing indicates that inspiration time or expiration time is stored in the Resmed files. (They are just not visible to me so far.) Are they calculated separately by the dataloader in OSCAR from the recorded flow numbers?
Thank you for your help!
RE: Where is Resmed Inspiration/Expiration Time in BRP or PLD file - pholynyk - 02-27-2021
The Resmed AutoSet does not report inspiration nor expiration times. It appears that only the VAuto reports those times in the PLD.edf file.
I'm not sure where the I and E times are calculated, nor the algorithm used. It is not in the loader, so I'll have to do some poking around in the code to find it.
RE: Where is Resmed Inspiration/Expiration Time in BRP or PLD file - JustaHoseHead - 02-28-2021
Thank you for taking time to look at my question.
I believe I have located the algorithm.After slogging through the master code, it seems it is in the calcs.cpp, starting at line 305, in the folder OSCAR-code-master\oscar\SleepLib.
I can look at this coding and reconstitute as pseudocode for my own calculation (in Octave), so that I can look at the breath variation statistics as a function of time.
This is a great board. I have learned a lot from it.
I have read some of your past posts, and am grateful we have dedicated volunteers like yourself!
RE: Where is Resmed Inspiration/Expiration Time in BRP or PLD file - happydreams - 03-02-2021
For what it is worth, for the ResMed VAuto, the signal names are BSITime and BSETime, for the inhalation and exhalation times in the PLD edf file. They are logged at a 2 second rate. There is also a signal called IERatio, which is also at a 2 second rate.
To find this information, I used pyEDFLib to extract the dictionary that has the channel information. There's probably an equivalent in EDFbrowser.
At least for my test file, the two signals were a bit noisy, with the exhalation times having more than twice as much noise.