10-26-2017, 11:34 AM
(This post was last modified: 10-26-2017, 11:39 AM by Aardvark08.)
RE: New Machine - Numbers Don't Match
Tremendous night last night on Resmed Airsense Autoset, after titrating using input from this forum. Then I glance at the machine display. 12.8 AHI!! ARGH!? How can this be? Reach for the SD card to run to the computer for Sleepyhead. No SD card! Oops. Get card from the computer in another room. Insert SD card, data is processed, run back to computer. Welcome screen pops up. Congratulations, AHI 0.12 !! What? Run back to machine, reinsert the card thinking maybe some data didn't transfer. Reconfirm display 12.8. Pull card - back to computer. Summary only data (no graphs) but still 0.12 AHI Little snippets of data for each of three sessions during the night confirm that Autoset brain was working, but clearly a fantastic night according to Sleepyhead and yours truly. Not so much according to machine display. Now I am more suspicious than ever of the accuracy of the machine display when EPR is in use (2x) Did not having the SD card in place somehow skew the data transferred when the SD was reinserted? Summary data show separate AHI for each of the sessions, Longest was .10, shortest .21
Comments? Please help me understand this.
RE: New Machine - Numbers Don't Match
I don't think EPR can effect how the machine displays anything. It does look like decimal point got misplaced though.
10-26-2017, 12:31 PM
(This post was last modified: 10-26-2017, 12:32 PM by Aardvark08.)
RE: New Machine - Numbers Don't Match
Thanks Walla Walla, that was my first reaction as well. However, displaying 12.8 when the AHI is 0.12 is quite a display error due to misplaced decimal. Although I admit it is circumstantially curious. I rather think it may be congruent with the results of an NCBI study I referenced in post #19 where engaging EPR 3 on this machine caused a discrepancy of more than 10 ( as I recall) between bench measurements and displayed AHI. I remain suspicious....
RE: New Machine - Numbers Don't Match
The Airsense Autoset 10 does not store detailed data, so when you forget to insert the SD card then put it in the next AM the data is worthless. The report of .12 seems to be a default or bug in sleepyhead when there is no data available. I have seen it a few times
10-26-2017, 12:41 PM
(This post was last modified: 10-26-2017, 12:42 PM by Spy Car.)
RE: New Machine - Numbers Don't Match
(10-21-2017, 08:21 AM)Sleeprider Wrote: I agree that the clusters of apnea look like a positional issue. What are the settings on the BiPAP 750? Your Sleepyhead chart does not match your pressure setting of 8-17, and both the chart and the statistics show your pressure reached only 15 cm (please minimize the monthly calendar). You may be using EPR at 2, and the statistics for some reason are only showing EPAP pressure.
Altitude can make a difference for some people, and we usually have seen people develop more central apnea. There is a possibility these events are improperly classified as obstructive, but I don't know of a good way to determine that from the machine or sleepyhead data. If you post a closeup of one of the apnea episodes, we might see something in the respiratory flow rate wave-form. Usually the best images cover about 2-5 minutes.
I experienced a similar anomaly with Sleepyhead graphs displaying only EPAP pressures (in green) and NOT IPAP pressures (in red) with my ResMed AirSence 10 AutoSet
after I imported 5 nights of data from a Bi-level (ResMed AirCurve 10) into the same user database I was using for the APAP.
Prior to that Sleepyhead displayed both EPAP and IPAP pressure from the APAP.
A workaround to get IPAP back is to go to the daily chart, place the cursor in the left margin (where it says "Pressure") and then to "Control-half-click" on a Mac (is this "Command-half-click on a PC?). This will bring up a dialogue box which has an option for "Plots." Under "Plots" there is a box that needs to be checked for IPAP.
I found this turned the IPAP pressure display back on
until I reviewed charts dates with Bi-level data, which (again) turned off the IPAP pressure display.
My guess is
Aardvark08 is experiencing the same bug in Sleepyhead.
Bill
RE: New Machine - Numbers Don't Match
So the Sleepyhead session AHI numbers are bonkers? The real AHI is what is shown in the display? Also, note that I don't have any graphs to show flow, pressure, etc.
RE: New Machine - Numbers Don't Match
Try downloading ResScan and see what it says.
RE: New Machine - Numbers Don't Match
They are bonkers only if you forget to put the SD card in before you start your sleep session. If you put the card in before you start the sleep session the data provided is invaluable.
RE: New Machine - Numbers Don't Match
(10-26-2017, 01:17 PM)TASmart Wrote: They are bonkers only if you forget to put the SD card in before you start your sleep session. If you put the card in before you start the sleep session the data provided is invaluable.
Right. The only time I've had false AHI numbers with Sleepyhead is when I've forgotten to reinsert my SD card after downloading to my computer.
Bill
10-26-2017, 01:27 PM
(This post was last modified: 10-26-2017, 01:31 PM by Reznik.)
RE: New Machine - Numbers Don't Match
AirSense 10 keeps two sets of data. The summary data (AHI, etc.), which is shown on the screen, is compiled on a daily basis based upon your actual usage of the machine, and is saved for some period of time even if you don't have an SD Card in the machine.
The detailed data (time of events, breath by breath, pressure at particular times) is stored only if you have an SD card in the machine at the time you're using it. Putting the SD card in later won't recover the detailed data. It's already gone. The machine dumped it while you were sleeping.
SleepyHead does not use the summary data generated by the AirSense 10 at all. It only relies upon the detailed data. It calculates its own set of summary data (AHI, etc.) based upon the detailed data on the SD Card.
So, if you use the machine for part or all of the night with the SD card out, the SleepyHead summary data will not match the AirSense 10's summary data. The AirSense 10's summary data will be based upon everything that happened, even those things that happened when the SD Card was not inserted. However, SleepyHead's summary will only be based upon what happened when the SD Card was inserted.
BTW- This is a good technique to use if you use your machine to dry wet hoses/masks or during the day to acclimate. Pull the SD Card out before you turn the machine on, and that activity won't be counted in SleepyHead.
In contrast, ResScan WILL show the summary data from the machine. It does NOT compute its summary data from the detailed data. So, if you use ResScan and want to exclude daytime activity (like mask drying or acclimating to the machine), you have to download last night's activity into ResScan first and then use the erase function in the clinical menu after you're done with your daytime activity.
