03-14-2014, 01:57 PM
(This post was last modified: 03-14-2014, 02:10 PM by justMongo.)
(03-14-2014, 01:01 PM)PsychoMike Wrote: Hi Dutch,
Not quite about the heartbeat
The ResMed machines use air pulses to see if the airway is open. It sends out it's pulses and looks at what happens to the pressure. With OSA, the airway is blocked so the pressure will rise much more (smaller volume) with each pulse than if the airway is open (CSA event with a much larger volume that includes the airway and lungs).
We're still only talking little puffs (not like it's trying to blow you up like a balloon), but the pulses are large enough and algorithm is sensitive enough to figure out whether it is OSA related or CSA related (so it can boost the pressure on the OSA ones and not the CSA ones)
Close enough for government work.
After 4 seconds of no flow, it modulates the pressure with a 1cm-H2O sine wave and listens to the reflection. It's more of a sonar like principle.
In the highly detailed data on ResScan, you can actually see the pressure modulation on the pressure graph during an apnea event.
It's really quite brilliant.
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