08-17-2020, 02:18 PM
(This post was last modified: 08-17-2020, 02:20 PM by Traveler58.
Edit Reason: clearity improvement
)
How does OSCAR tell clear-airway apnea apart from obstructive apnea?
OSCAR has been a very useful tool to me.
Just one question, how does it tell clear-airway apart from obstructive apnea based on the data from my Airsense 10. Are the relevant parameters adjustable on the users' end?
08-17-2020, 02:34 PM
(This post was last modified: 08-17-2020, 02:36 PM by staceyburke.)
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
Your machine sends a pulse of air if there is no obstruction it is classified as a central.
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
The Resmed machines use FOT
Central sleep apnoea detection
Central sleep apnoea (CSA) detection uses the Forced Oscillation Technique (FOT) to determine a whether a patient’s airway is open or closed during an apnoea. When an apnoea has been detected, small oscillations in pressure (1 cm H2O peak-to-peak at 4 Hz) are added to the current device pressure. The CSA detection algorithm uses the resulting flow and pressure (determined at the mask) to measure whether the airway is open or closed.
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
But the Resmed rep I called today told me the machine couldn't tell them apart.
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
(08-17-2020, 02:44 PM)Traveler58 Wrote: But the Resmed rep I called today told me the machine couldn't tell them apart.
Apparently this person is ignorant about his own products. The FOT algorithm has been used since the S9 series to distinguish between Obstructive and Central events. OSCAR only reports what the machine reports.
Hope this helps.
A.Becker
PAPing in NE Ohio, with a pack of Cairn terriers
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
Possible the Rep meant that the Device could not "treat" Clear Airways. But as far as recognizing the difference, it's as jaswilliams stated above.
The FOT determines whether the airway is open (no obstruction and no attempt to breathe) which is then flagged as a Clear Airway, or if the airway is collapsing (an obstruction with an attempt to breath) which is then flagged as an Obstruction.
If a CA is detected, the machine will not raise the pressure to try and treat it, but will raise the pressure for an Obstruction.
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
https://erj.ersjournals.com/content/17/3/456
Abstract
The forced oscillation technique (FOT) is a noninvasive method that is useful for assessing airway obstruction and for titrating continuous positive airway pressure (CPAP) in patients with sleep apnoea. The aim was to evaluate the routine applicability of a simplified FOT set-up based on recording pressure and flow at the level of the CPAP device, i.e. obviating the need for connecting the transducers to the nasal mask.
A correction to account for the tubing and the exhaust port was applied. This simplified FOT was evaluated on nine patients with moderate or severe sleep apnoea during routine CPAP titration. Patient impedance measured by the simplified FOT (|Z|) was compared with actual patient impedance (|Zrs|) measured simultaneously with a reference FOT based on recording pressure and flow at the nasal mask.
An excellent agreement was found between |Z| and |Zrs| over the wide range of airway obstruction explored (4.8–72.1 cmH2O·s·L−1): |Z|=|Zrs|×0.86+1.3 cmH2O·s·L−1 (r= 0.99). Moreover, the simplified and the conventional FOT settings detected the same respiratory events during sleep.
These results demonstrate that this simplified FOT is applicable for measuring airway obstruction during routine sleep studies in patients with sleep apnoea.
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
which all means they send a puff of air and if no abnormal resistance it is a central
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
(08-17-2020, 02:44 PM)Traveler58 Wrote: But the Resmed rep I called today told me the machine couldn't tell them apart.
I believe they can and the Resmed Representative did not either know or did not want to go into detail possibly. The reason I say this is I downloaded Resmed software from this site and it registers central apnea. I could not take a snap shot like on Oscar using the F12 key so I took a picture of a session with a Central apnea on my phone camera . I bought my 2nd new Resmed airsense 10, auto start and have been very impressed with it and my 5year old model.
Oscar is much better software for a person who wants to know what is happening while you sleep & to tweak his or her settings with the help of folks like on this forum or yourself.
Some health care workers like the auto type because it covers such a wide range of issues and they kind of cover their _ _s, that is what I figured when I got my first Respironics Remstar /Aflex auto Cpap 12+ years ago.
You can download Resmed 5.9 clinical software from this site only. It is still a good tool to help Resmed cpap owners.
RE: How does OSCAR tell clear-airway apnea apart from obstructive apnea?
(08-17-2020, 03:26 PM)staceyburke Wrote: which all means they send a puff of air and if no abnormal resistance it is a central
Philips Respironics uses a single puff of air at 1.5 cm to test of apnea type. FOT is 1-cm fluctuations at 4 times per second after the event reaches about 6-8 seconds. I can't tell you how it is interpreted, but there is a difference.
