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+--- Thread: Could someone check me on this? (/Thread-Could-someone-check-me-on-this)
Could someone check me on this? - justMongo - 03-16-2014
I've just had my 3rd night in a row with zero AHI. I'm getting suspicious. So, when I look at the flow data, I see some flat spots that I think should have been scored as central apnea. There is no flow limitation at that spot. The respiratory rate graph takes a short dive from about 15 bpm to 5 bpm.
I'm running my S9 VPAP Auto in S mode. If I am reading the manual correctly, it does not score CA's in that mode. Am I reading that right?
If that's true, seems to me like I should go to auto mode and open up the IPAP/EPAP a couple of cm-H2O and let it seek -- plus it would score CA's. (Maybe set my floor EPAP to 9; and my top IPAP to 16)
See present settings in my profile. We have some really smart folks on the forum -- and I appreciate a check of my reading comprehension.
RE: Could someone check me on this? - me50 - 03-16-2014
(03-16-2014, 09:04 AM)justMongo Wrote: I've just had my 3rd night in a row with zero AHI. I'm getting suspicious. So, when I look at the flow data, I see some flat spots that I think should have been scored as central apnea. There is no flow limitation at that spot. The respiratory rate graph takes a short dive from about 15 bpm to 5 bpm.
I'm running my S9 VPAP Auto in S mode. If I am reading the manual correctly, it does not score CA's in that mode. Am I reading that right?
If that's true, seems to me like I should go to auto mode and open up the IPAP/EPAP a couple of cm-H2O and let it seek -- plus it would score CA's. (Maybe set my floor EPAP to 9; and my top IPAP to 16)
See present settings in my profile. We have some really smart folks on the forum -- and I appreciate a check of my reading comprehension.
first thing I would do is unplug your machine for a while and then plug it back in. if any event is under 10 seconds, it won't count it. I don't know about reporting a CA or not in S mode. I am too new at vpap to know that but there are others that will be able to help you.
I used mine in s mode for a week and switched back to auto mode. it is easier on me to not have a set pressure all night long. sorry I can't help you more.
if you can post your data graph, that would be helpful.
RE: Could someone check me on this? - c0reDump - 03-16-2014
Could try holding your breathe for 15 seconds to force an event and ensure it is scored. You should be able to force an obstructive event or a central event if you understand the mechanics of each.
RE: Could someone check me on this? - justMongo - 03-16-2014
(03-16-2014, 09:10 AM)me50 Wrote: first thing I would do is unplug your machine for a while and then plug it back in. if any event is under 10 seconds, it won't count it. I don't know about reporting a CA or not in S mode. I am too new at vpap to know that but there are others that will be able to help you.
I used mine in s mode for a week and switched back to auto mode. it is easier on me to not have a set pressure all night long. sorry I can't help you more.
if you can post your data graph, that would be helpful.
I did power cycle the machine last evening.
I think this should be scored as an open airway event. (CSA)
The flow goes to zero for about 20 seconds. The pressure stays at EPAP.
![[Image: flowzero.jpg]](http://i923.photobucket.com/albums/ad76/NETTUEMsc4V92qMY/flowzero.jpg)
From the Manual for the S9 VPAP Auto** Fair Use
"Central sleep apnea
In VAuto or CPAP mode, these VPAP devices detect both obstructive and central sleep apneas (CSA).
CSA detection uses the Forced Oscillation Technique (FOT) to determine the state of the patient’s airway
during an apnea. When an apnea has been detected, small oscillations in pressure (1 cm H2O peak-topeak
at 4 Hz) are added to the current device pressure. The CSA algorithm uses the resulting flow and
pressure (determined at the mask) to measure the airway patency."
RE: Could someone check me on this? - c0reDump - 03-16-2014
When using SleepyHead, you can see that oscillation (when the machine is determining what kind of apnea is in progress) in the "mask pressure" graph. I don't see that in your ResScan graphs -- dunno if that software normally shows that or not.
It sure looks like you didn't breathe for 20 seconds or so though, so would think that is an apnea that should've been scored. Your leak-rate seems pretty high and might be why it didn't score the event...
RE: Could someone check me on this? - justMongo - 03-16-2014
(03-16-2014, 02:37 PM)c0reDump Wrote: When using SleepyHead, you can see that oscillation (when the machine is determining what kind of apnea is in progress) in the "mask pressure" graph. I don't see that in your ResScan graphs -- dunno if that software normally shows that or not.
It sure looks like you didn't breathe for 20 seconds or so though, so would think that is an apnea that should've been scored. Your leak-rate seems pretty high and might be why it didn't score the event...
You are misinterpreting the leak rate graph. That blue line at the bottom is the leak rate; and it is zero. The line your are looking at is the maximum acceptable leak rate.
Here's my leak rate for that entire night.
![[Image: LeakRate.jpg]](http://i923.photobucket.com/albums/ad76/NETTUEMsc4V92qMY/LeakRate.jpg)
RE: Could someone check me on this? - c0reDump - 03-16-2014
Thanks for the correction, didn't realize that redline is the high-bar. I've not had much luck getting ResScan to work reliably for me so I'm not used to those graphs.
However, I've gotten into the habit of checking the onscreen display every morning -- I've had nights where the S9 reported higher AHI numbers (via the "Info" button) than what SleepyHead was getting from the card -- haven't seen this problem since replacing the SD-Card. You might want to double check that.
RE: Could someone check me on this? - TheWerkz - 03-18-2014
Don't forget, different brand masks and models will have their own different built-in leak rates too.
As long as you're not spiking on the graph there's nothing to worry about.
ResScan will also zoom-in on the graphs also but, it's not easy/simple to do since SleepyHead just requires a mouse click.
In 7 years with CPAP I've only had an actual AHI of "0.0" 2 or 3 times, it was always on a shorter sleep session of 3 to 4 hours, I do average 0.5 to 0.9 a lot while getting 8+ hours of sleep.
There ARE bugs in SleepyHead and it does act "funky" (technical term) especially if you have more than one sleep cycle per 24 hour period, like turning the machine off to go to the bathroom and then back on etc., the developer Mark is aware of the bugs but hasn't squashed them all yet, the problems are mostly with ResMed data and how the program parses it than the other machines it supports.
For the best numbers accuracy you need to use ResScan but, it's much more "clunky" (another technical term) to use and navigate but the numbers should coincide more accurately with your S9's display info.
Ren
RE: Could someone check me on this? - archangle - 03-21-2014
(03-16-2014, 09:04 AM)justMongo Wrote: I've just had my 3rd night in a row with zero AHI. I'm getting suspicious. So, when I look at the flow data, I see some flat spots that I think should have been scored as central apnea. There is no flow limitation at that spot.
Why do you think it's central, and not obstructive? The S9 series distinguishes central from obstructives via the FOT pulses. There's nothing on the waveform that you can look at to tell them apart.
Did it indicate an apnea of any type at that point?
Does your machine ever indicate a central apnea? I think some VPAP machines will simply never indicate a central apnea. It's sort of some arrogant idea that "I'm not going to let you have a central, I'll force you to breathe, so I won't score any centrals."