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

Why do events occur with APAP machines
#11
I found, after videoing entire nights of myself sleeping, that sometimes events are recorded while I am rolling around in bed. Many times, I tend to hold my breath, I also tend to while rolling around trying to get comfortable which ends up showing as an obsrtructed airway or hypopnea.
Post Reply Post Reply
#12
(04-13-2017, 11:49 AM)PsychoMike Wrote: An APAP machine is nice in that it responds to events...but it is not predictive.  As a result, they chase events, rather than actively prevent them.

You can have an APAP set for a pressure range of 6-20 cm H20 (common for a DME to do this out of the box and used to get a bit of a rough titration on pressure in the first few days)...but if you need a pressure of 12 cm H20, you'll have events until it responds enough to have you at the pressure you need.  When you stop having events, the machine then wants to return to the minimum pressure so it starts dropping the pressure and you get events again. The cycle continues unless the settings are changed to better reflect the actual therapy you need.

APAPs are wonderful when they are set up correctly and can help for the times when you need that adjustment because of how you're sleeping, the head cold you have, it's a full moon (or whatever might influence your sleep apnea at the time). But just like any other computer driven hardware, they need to be set up right (correct base pressure and range) otherwise garbage in = garbage out.

shouldnt they learn to adjust without being reset

i thought some of them claimed to learn what settings were working best to use as a baseline for the next time
Post Reply Post Reply
#13
None of these machines "learn" anything. They only react to events after they have occurred due to pre-programmed algorithms. They have no built in intelligence...
Post Reply Post Reply


#14
(04-13-2017, 05:59 PM)Marillion Wrote: None of these machines "learn" anything.  They only react to events after they have occurred due to pre-programmed algorithms.  They have no built in intelligence...

depends what you call learning and intelligence

any servo reacts immediately to changing conditions
that is equivalent to learning in my book

but for longer term variations you need another control mechanism 
the best we can do is have the algorithm remember the history and try to guess at the best start point
or rate of change to get to the current correct state for best help with our breathing

the problem is that we change long term, we change short term, and we change in between


if we had regular changes then those could be allowed for
when we have irregular changes the algorithm has to try to compute a new set point that is proper
and then hunt for the optimum 

all in all the machine with the adaptive algorithm should almost always beat one with a fixed rate that is only changed by the DME next week or month not by the machine in real time or NRT as meets our needs immediately
Post Reply Post Reply
#15
(04-13-2017, 11:49 AM)PsychoMike Wrote: An APAP machine is nice in that it responds to events...but it is not predictive.  As a result, they chase events, rather than actively prevent them.

Current Resmed auto machines try to be predictive by reacting to the apnea precursors of snore and flow limitations. Sometimes however obstructive apneas occur without these precursors.

Best Regards,

PaytonA

Admin Note:
PaytonA passed away in September 2017
Click HERE to read his Memorial Thread

~ Rest in Peace ~
Post Reply Post Reply
#16
(04-13-2017, 11:49 AM)PsychoMike Wrote: APAPs are wonderful when they are set up correctly 

What is the correct way of setting up an APAP machine ? 
I have had to experiment (with a great price to pay the following day) with changing (+/-) the minimum pressure till I just started using a minimum pressure closer to my prescription. I'd interested to know how others have set up their APAPs correctly and hope I haven't stuffed up in setting mine up.
Post Reply Post Reply


#17
There is a difference between ResMed and Respironics.

Basicly you set minimum so you don't have to chase your initial events.

Set maximum to prevent running away high and disrupting sleep about 1 cm over the max you typically see

My max is set at 25 only because I can luckily handle the pressure without discomfort and it never goes there.
Post Reply Post Reply
#18
(04-14-2017, 12:01 PM)PaytonA Wrote:
(04-13-2017, 11:49 AM)PsychoMike Wrote: An APAP machine is nice in that it responds to events...but it is not predictive.  As a result, they chase events, rather than actively prevent them.

Current Resmed auto machines try to be predictive by reacting to the apnea precursors of snore and flow limitations. Sometimes however obstructive apneas occur without these precursors.

Best Regards,

PaytonA

Very true, PaytonA...but they are still reactive to the snores and flow limitations (trying to head off the "main event" by reacting to the precursors)....still following an A (snore)->B (apnea)->C (change pressure) model, just trying to adjust at A, rather than recording A and adjusting after B Wink
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
#19
(04-17-2017, 10:46 PM)BHappy Wrote:
(04-13-2017, 11:49 AM)PsychoMike Wrote: APAPs are wonderful when they are set up correctly 

What is the correct way of setting up an APAP machine ? 
I have had to experiment (with a great price to pay the following day) with changing (+/-) the minimum pressure till I just started using a minimum pressure closer to my prescription. I'd interested to know how others have set up their APAPs correctly and hope I haven't stuffed up in setting mine up.

Probably best to start a new thread for yourself on this so we're not hijacking this thread.

In a nutshell though, most folks here start with their prescription values and then use programs like Sleepyhead to see what is going on. Then they make small changes and give it some time (a week or two) to see the difference before trying the next change.
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


#20

xxyzx: "... but for longer term variations you need another control mechanism, the best we can do is have the algorithm remember the history and try to guess at the best start point, ..."


On the Respironics I own, there is something (when enabled) that selects a smart starting pressure, based on last 30 hours of therapy.  I had it enabled when I first got it, and it moved my start pressure to 6.5 from 6, and then a week or two later, moved it back to 6.  I turned the feature off.

QAL
Dedicated to QALity sleep.
You'll note I am listed as an Advisory Member. I am honored to be listed as such. See the fine print - Advisory Members as a group provide advice and suggestions to Apnea Board administrators and staff concerning Apnea Board operation and administrative policies. Membership in the Advisory Member group should not be understood as in any way implying 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
  NEW Apap bought tonight razormarsh 1 12 11 minutes ago
Last Post: Sleeprider
  Pressure raises when there is ca events yankees123 25 612 11 hours ago
Last Post: Sleeprider
  changing from CPAP to APAP- which pressure to use? cbrts765 16 581 12-08-2017, 09:05 AM
Last Post: Sleep2Snore
  [Pressure] How I decided on my APAP pressure numbers on my own DanGagner 14 345 12-06-2017, 09:26 PM
Last Post: DanGagner
  First Nights of APAP...All Centrals! Allessio77 31 823 12-04-2017, 11:21 AM
Last Post: Dawnstar
  Events nanniesitter 12 287 12-02-2017, 08:09 PM
Last Post: HalfAsleep
  Changing from APAP to Bilevel alps 13 369 12-02-2017, 01:15 PM
Last Post: alps

Forum Jump:

New Posts   Today's Posts




About Apnea Board

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

For any more information, please use our contact form.