Hello Guest, Welcome to Apnea Board !
As a guest, you are limited to certain areas of the board and there are some features you can't use.
To post a message, you must create a free account using a valid email address.

or Create an Account


New Posts   Today's Posts

Different AHI reported by Oscar and my machine
#1
Different AHI reported by Oscar and my machine
Hello,

I'm using my CPAP machine since a month. Today, my machine and myAir app reports an AHI of 0.8 but oscar reports only 0.53. This is the first time I notice a difference between Oscar and my machine. What can explain that?

Thank you!
Post Reply Post Reply
#2
RE: Different AHI reported by Oscar and my machine
OSCAR can only report what the Cpap writes to the SD card.

Do you by any chance have a session turned off?  Check the OSCAR daily page on the bottom left side bar for sessions.

You can post an OSCAR daily chart here and we can take a look.

Follow the links in my signature line to guide you.
OpalRose
Apnea Board Administrator
www.apneaboard.com

_______________________
OSCAR Chart Organization
How to Attach Images and Files.
OSCAR - The Guide
Soft Cervical Collar
Optimizing therapy
OSCAR supported machines
Mask Primer



INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE.  ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA.  INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply
#3
RE: Different AHI reported by Oscar and my machine
Hello,

Seem like there is only one session. Yesterday, I noticed my tube was still wet at night because of the morning cleaning. I made the machine working with the mask leak test mode for some minutes to dry it. I don't see this time on oscar (I don't expect it, it's normal I guess?).


Thank you!


Attached Files Thumbnail(s)
       
Post Reply Post Reply
#4
RE: Different AHI reported by Oscar and my machine
The running time between myAir and oscar is in sync.


Attached Files Thumbnail(s)
   
Post Reply Post Reply
#5
RE: Different AHI reported by Oscar and my machine
You seem to be talking about 3 different reporting sources, your CPAP, MyAir, and OSCAR.  If you see a different value on your CPAP, the default reporting is a month.  You can set the reporting period to daily, week, month, 3 months, and 6 months, too.  The CPAP will reset back to a monthly reporting if you unplug it.

- Red
Crimson Nape
Apnea Board Moderator
www.ApneaBoard.com
___________________________________
Useful Links -or- When All Else Fails:
The Guide to Understanding OSCAR
OSCAR Chart Organization
Attaching Images and Files on Apnea Board
Apnea Helpful Tips

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply
#6
RE: Different AHI reported by Oscar and my machine
Hello,

Yes 3 sources, but only one differs.

- CPAP machine (display results was set for 1 day, not the default of 1 month) and myAir for last night both reports AIH of 0.8
- Oscar is the only one reporting 0.53.
Post Reply Post Reply
#7
RE: Different AHI reported by Oscar and my machine
I can think of 2 possibilities.  
  1. OSCAR did not import all your sessions.  Try reimporting to see if this corrects this.
  2. The numeric resolution of the calculations between OSCAR (more digits) versus the other two can produce an overall difference.  This is particularly true the more sessions you have in a day's data.
Quick math on an 8-hour sleep session equates to a 2 event difference.

- Red
Crimson Nape
Apnea Board Moderator
www.ApneaBoard.com
___________________________________
Useful Links -or- When All Else Fails:
The Guide to Understanding OSCAR
OSCAR Chart Organization
Attaching Images and Files on Apnea Board
Apnea Helpful Tips

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply
#8
RE: Different AHI reported by Oscar and my machine
I tried re-importing, same result. There is only one session.

I just uploaded the data to sleephq and it reports 0.53 like Oscar. Weird.

No big deal I guess.
Post Reply Post Reply
#9
RE: Different AHI reported by Oscar and my machine
It should report the same, since they used OSCAR's code for theirs.

- Red
Crimson Nape
Apnea Board Moderator
www.ApneaBoard.com
___________________________________
Useful Links -or- When All Else Fails:
The Guide to Understanding OSCAR
OSCAR Chart Organization
Attaching Images and Files on Apnea Board
Apnea Helpful Tips

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply
#10
RE: Different AHI reported by Oscar and my machine
This is a rounding error caused by the different way ResMed programs and OSCAR determine the length of a session. ResMed software (MyAir, AirView, display on machine) rounds session lengths to the nearest minutes. If there are multiple sessions, the rounding occurs on each session before they are added together to determine total time for the day. AHI is then calculated as number of events / total time.

The CPAP machine records each session length in microseconds, which is what OSCAR uses in its calculations. When it then makes the AHI calculation, it has a slightly different total time than ResMed software so shows a slightly different AHI.

The difference in the resulting AHI is not clinically significant.
Useful links
Download OSCAR (current version is 1.5.1)
Best way to organize charts
How to attach charts to your post

Apnea Board Monitors are members who help oversee the smooth functioning of the Board. They are also members of the Advisory Committee which helps shape Apnea Board's rules & policies. Membership in the Advisory Members group does not imply medical expertise or qualification for advising Sleep Apnea patients concerning their treatment.
Post Reply Post Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Intermittent use of C-PAP machine and OSCAR monitoring Thanassis 6 240 02-27-2024, 10:52 AM
Last Post: Thanassis
  OSCAR has never seen my machine's data before! PappaJoe 9 510 02-14-2024, 02:29 PM
Last Post: Crimson Nape
  Setup of New Machine in OSCAR Melman 1 521 10-19-2022, 05:32 PM
Last Post: pholynyk
  Not able to open Oscar on a Window 10 machine John70 2 608 06-19-2022, 06:10 PM
Last Post: Crimson Nape
  OSCAR: Couldn't Find Valid Machine Data Kyriosjon 11 1,340 05-24-2022, 10:34 PM
Last Post: Gideon
  Changing cpap machine settings in Oscar Sofie 5 2,036 03-26-2022, 11:24 PM
Last Post: GuyScharf
  New Machine (DS2) and new to OSCAR NoSnoreDave 2 765 02-22-2022, 01:21 PM
Last Post: NoSnoreDave


New Posts   Today's Posts


About Apnea Board

Apnea Board is an educational web site designed to empower Sleep Apnea patients.