General Discussion on any topic relating to CPAP and/or Sleep Apnea.
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linuxman
- Posts: 235
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- Location: Indiana
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by linuxman » Fri Feb 24, 2017 11:53 am
palerider wrote:linuxman wrote: MAF sensor (assuming they one of those..could also just be motor rpm as that's a proxy for air flow rate).
what??? no, sensirion 1-100544-01 flow sensor
Fair enough. I didn't say a sensor was not being used, just that it would be possible to measure flow without a sensor. The motor rpm would map directly to air flow as long as the fan blades and outlet port don't suddenly change shape while in use.
palerider wrote:linuxman wrote: I'd think a bigger issue would be when there is rapidly *changing* leak rate. Those could be hard to distinguish from breaths in some case.
one would think not, leaks never push back like exhalations.
Yes exhalations would create a temporary pressure increase that should be separable from a decreasing mask leak. Inhalations on the other hand are just system volume increases, and could well look like an rapidly increasing leak.
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palerider
- Posts: 32300
- Joined: Wed Dec 16, 2009 5:43 pm
- Location: Dallas(ish).
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by palerider » Fri Feb 24, 2017 12:02 pm
linuxman wrote:palerider wrote:linuxman wrote: MAF sensor (assuming they one of those..could also just be motor rpm as that's a proxy for air flow rate).
what??? no, sensirion 1-100544-01 flow sensor
Fair enough. I didn't say a sensor was not being used, just that it would be possible to measure flow without a sensor. The motor rpm would map directly to air flow as long as the fan blades and outlet port don't suddenly change shape while in use.
*IF* it weren't possible for air to slip around the blades... but, yeah, you could get a ballpark number, but would you really want to have your treatment figured by that?
resmeds don't measure the motor RPM... not sure about respironics, they do use more than three wires into the motor.
linuxman wrote:palerider wrote:linuxman wrote: I'd think a bigger issue would be when there is rapidly *changing* leak rate. Those could be hard to distinguish from breaths in some case.
one would think not, leaks never push back like exhalations.
Yes exhalations would create a temporary pressure increase that should be separable from a decreasing mask leak. Inhalations on the other hand are just system volume increases, and could well look like an rapidly increasing leak.
the software would have to be pretty dumb to not be able to separate rhythmic "rapidly increasing leaks" without any concomitant rapidly decreasing flows from actual leaks.
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Accounts to put on the foe list: dataq1, clownbell, gearchange, lynninnj, mper!?, DreamDiver, Geer1, almostadoctor, sleepgeek, ajack, stom, mogy, D.H., They often post misleading, timewasting stuff.