SleepyHead resmed loader

[jedimark]

Hi all,

I finally started on finishing SleepyHead's ResMed EDF support.. All the EDF dirty work is done.. Now it's just sorting out whats what..

I've already figured out the flowrate waveform, and Hypopnea/Obstructive/Clear airway events. This is working nicely already, and my event timing matches up on the overlays (yay!)

Not 100% sure which is which of the following EDF data fields, so I thought I'd ask for more info about them here... Snore & Leak are fairly obvious, I think FFL is flow limitation.. but not sure about the rest. (the first 3 are pressures, but what type/kind/whatever?)

(These are from the xxxxxxxxx.PLD.edf files..)

Mask Pres
Therapy Pres
Exp Press
Leak
RR
Vt
MV
Snore Index
FFL Index

Also, the EDF file containing the flow waveform (xxxxx.BRP.edf) has another waveform attached called Mask Pres, on top of the one above.. What is this?

[Breathe Jimbo]

my event timing matches up on the overlays (yay!)

Yay, indeed, as that appears to resolve the so-called "data skew bug" in the S9 series!

[jedimark]

Okay, Mask Pressure seems to be the only one with graphable pressure data. Still don't know what the others do.

I figure MV = Minute Ventilation. Have no idea what it does or means. Looks pretty.

Leak doesn't look like leak data, however Vt does..

RR has a nice graph, but I have no idea what it is or does.

Snore graphs nicely.. Much more detailed than PRS1

[Slinky]

VT is Tidal Volume = volume of air inspired or expired in one respiratory cycle (breath).

RR is Respiratory Rate = frequency of breathing, expressed as the number of breaths per minute.

MV is Minute Ventilation = the volume of air breathed in (or out) w/in any 60 second period.

Leak is derived by analyzing the inspiratory and expiratory airflows, together w/the expected mask vent flows.

[jedimark]

Thankyou Slinky!!!

[jedimark]

Leak is derived by analyzing the inspiratory and expiratory airflows, together w/the expected mask vent flows.

I take it the other Mask Pressure data set in the same file as the flow rate is the other part of this?

[Otter]

Hi all,

I finally started on finishing SleepyHead's ResMed EDF support.. All the EDF dirty work is done.. Now it's just sorting out whats what..

Woot!

Not 100% sure which is which of the following EDF data fields, so I thought I'd ask for more info about them here... Snore & Leak are fairly obvious, I think FFL is flow limitation.. but not sure about the rest. (the first 3 are pressures, but what type/kind/whatever?)

(These are from the xxxxxxxxx.PLD.edf files..)

Mask Pres
Therapy Pres
Exp Press
Leak
RR
Vt
MV
Snore Index
FFL Index

Also, the EDF file containing the flow waveform (xxxxx.BRP.edf) has another waveform attached called Mask Pres, on top of the one above.. What is this?

Mask pressure is just what it says, the pressure at the mask. With this you can see the effect of EPR. You can also see yourself hyperventilate and scream into the mask if you freak out because you are critically low on serotonin, really need to sleep, and can't get the mask to seal. Hence, it must be an actual meausred pressure rather than a target. If you look at Mask Pressure and Flow together, you can see what the pressure actually was when an event occurred.

Therapy pressure is the machine's target IPAP in APAP mode. It does not show the effect of EPR, but is useful for figuring out what the machine thought you needed. This is the one you'd look at to adjust max and min apap pressures.

Not sure what Exp Press is.

I think Vt is tidal volume. The units are liters.

MV is in "liters/mi", according to EDF Browser. Liters/minute? Trace follows Vt, but I'm not sure what it is.

Leak is in liters/sec, and I thought it was leak data. What should leak data look like?

[Otter]

Leak is derived by analyzing the inspiratory and expiratory airflows, together w/the expected mask vent flows.

I take it the other Mask Pressure data set in the same file as the flow rate is the other part of this?

Seems logical they'd calculate expected flow rates from Mask Pressure and the vent PQ curve for whichever mask you selected.

[jedimark]

I'll have to hack around with the leak stuff. I'll figure it out eventually.

I'm at the point I can start the funky graph layout stuff based on machine capabilities (eg, the S9 has more goodies than PRS1)

Things are starting to fall into place.

[Slinky]

I would guess that Exp Press = expiratory pressure.

Hey, jedimark, I don't necessarily know or understand what the devil I was talking about. Those were the definitions from the ResScan definition page.

The full definition at Leak was:
Leak is an estimate of the total rate of air escaping due to mouth and mask leaks.
It is derived by analyzing the inspiratory and expiratory airflows, together w/the expected mask vent flows.
High or changing leak rates may affect the accuracy of other measurements.

Those who are adept at browsing thru the Resmed Clinicians/Professionals pages at the Resmed website can probably find a little more explicit information.

[Otter]

I would guess that Exp Press = expiratory pressure.

Spent a few minutes looking at Exp Press, and it seems to be the target EPAP pressure, Therapy Press - EPR. With 3 cm EPR, it's always Therapy Press - 3.

The full definition at Leak was:
Leak is an estimate of the total rate of air escaping due to mouth and mask leaks.
It is derived by analyzing the inspiratory and expiratory airflows, together w/the expected mask vent flows.
High or changing leak rates may affect the accuracy of other measurements.

Those who are adept at browsing thru the Resmed Clinicians/Professionals pages at the Resmed website can probably find a little more explicit information.

The Data Management Guide says the same thing. I was hoping for more, because the DMG is the only place I found a definition for hypopnea.

[Slinky]

JediMark, do you have a pdf of the Resmed S9 VPAP Auto Clinicians Manual?? That may have more comprehensive information/explanation of the various terms and what they portend.

On the other hand, the Resmed S8 VPAP Auto (released January 2008) Clinicians Manual was MUCH more explicit and informative than the Resmed S8 VPAP Auto 25 (released July 2008) Clincians Manual.

Just a thuoght.

[Otter]

The DMGs would be at least useful as a quick reference. As I recall, the DMG gave me what I found in the S8 Clinicians manual but could not find in the manual for the S9. Still pretty sketchy, but orders of magnitude better than a face that turns from green to red at an unspecified leak rate.

Autoset
http://www.resmed.com/int/assets/docume ... ow_eng.pdf

Bilevel
http://www.resmed.com/us/assets/documen ... lo_eng.pdf

[LittleRedTruck]

This is wonderful, your designing this! Wondering when it should be available for us S9 users and if it will function for the S9 Vpap auto. thanks, dan

[Otter]

Just a thought: It would be nice to be able to superimpose Therapy Press and Exp Press on Mask Press. I've done that a couple times in EDFB with TP and MP, but it's a PITA to set up. It's nice to see them all together, though, and as TP and EP will be at the extremes, and MP will meet them only briefly, it wouldn't be cluttered.