RE: Need some advice on APAP Range settings
(04-10-2016, 07:24 AM)green wings Wrote: I'm just curious. If you want to check therapy pressure while someone is using the device, where does a manometer attach? I looked at a couple for sale on an online CPAP supplies site, but they looked like they would attach to the end of the hose where it normally attaches to the mask.
I've never used one, but I believe it is only used to check to see if the machine is putting out the correct pressure. I don't think you can check that while using it.
RE: Need some advice on APAP Range settings
(04-10-2016, 07:45 AM)OpalRose Wrote: (04-10-2016, 07:24 AM)green wings Wrote: I'm just curious. If you want to check therapy pressure while someone is using the device, where does a manometer attach? I looked at a couple for sale on an online CPAP supplies site, but they looked like they would attach to the end of the hose where it normally attaches to the mask.
I've never used one, but I believe it is only used to check to see if the machine is putting out the correct pressure. I don't think you can check that while using it.
It should work with someone using it. It is, after all, just a pressure gauge and pressure gauges are closed systems. You should be able to monitor the system pressure by connecting the manometer to the cpap hose via a tee and short hose, possibly as it comes out of the machine. My question is would the gauge be responsive enough to accurately register the pressure changes.
04-10-2016, 12:08 PM
(This post was last modified: 04-10-2016, 01:07 PM by vsheline.)
RE: Need some advice on APAP Range settings
(04-10-2016, 11:13 AM)pupcamper Wrote: (04-10-2016, 07:45 AM)OpalRose Wrote: (04-10-2016, 07:24 AM)green wings Wrote: I'm just curious. If you want to check therapy pressure while someone is using the device, where does a manometer attach? I looked at a couple for sale on an online CPAP supplies site, but they looked like they would attach to the end of the hose where it normally attaches to the mask.
I've never used one, but I believe it is only used to check to see if the machine is putting out the correct pressure. I don't think you can check that while using it.
It should work with someone using it. It is, after all, just a pressure gauge and pressure gauges are closed systems. You should be able to monitor the system pressure by connecting the manometer to the cpap hose via a tee and short hose, possibly as it comes out of the machine. My question is would the gauge be responsive enough to accurately register the pressure changes.
A "tee" adapter could be used to connect to both the mask and the manometer.
Available for around US$ 35 from Supplier #2 on our Supplier List is the cheap type of commercial manometer which has a light floating ball which rapidly bobbles up and down in the airflow of a calibrated narrow funnel. Its average height (as it bobbles) is raised or lowered by the speed of the air leaking/rushing past it. In this case it is not a closed system.
If using a free homemade manometer based on how many centimeters a column of water rises in a U shaped clear tube, this would work in a closed system without air leaks, but the column of water would have hugely greater mass than the light floating ball in the cheap commercial manometer, and my guess is it would be too slow and oscillatory to measure our inhale versus exhale pressures. (Although very slow it would be very accurate, excellent for checking pressures in a constant-pressure CPAP mode.)
If one were to breathe slowly and evenly, perhaps 3 second inhale followed by 3 second exhale, should be no problem measuring IPAP versus EPAP if using the relatively speedy cheap commercial manometer.
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RE: Need some advice on APAP Range settings
(04-10-2016, 07:24 AM)green wings Wrote: I'm just curious. If you want to check therapy pressure while someone is using the device, where does a manometer attach? I looked at a couple for sale on an online CPAP supplies site, but they looked like they would attach to the end of the hose where it normally attaches to the mask.
to *properly* use a manometer, you need an appropriate leak in the circuit, since that's how the machine is designed to be used.
I use oxygen adapters. they don't provide any extra resistance to flow, and just have a small hole on the side, and a spot for a hose to hook up... works quite well.
RE: Need some advice on APAP Range settings
(04-10-2016, 07:45 AM)OpalRose Wrote: I've never used one, but I believe it is only used to check to see if the machine is putting out the correct pressure. I don't think you can check that while using it.
oh, you can, quite easily.
I've got a digital differential manometer, and one of the experiments that I did was to tap the circuit at the mask, and at the back of the machine, with a 3 meter hose and antibacterial filter, then compare the pressure at the machine vs at the mask, while not breathing, breathing normally, and breathing big gulps of air.
my pressure was set 18/13, and at the mask, it was very close to that.
at the machine, pressure swung from 14 to 28cm pressure as the machine compensated for the flow resistance of the filter, hose and mask... it was interesting.
the peaks at the machine were much lower, of course, when breathing normally than when taking big gulps of air.
RE: Need some advice on APAP Range settings
(04-10-2016, 11:13 AM)pupcamper Wrote: My question is would the gauge be responsive enough to accurately register the pressure changes.
oh yes.
RE: Need some advice on APAP Range settings
(04-10-2016, 12:08 PM)vsheline Wrote: Available for around US$ 35 from Supplier #2 on our Supplier List is the cheap type of commercial manometer which has a light floating ball which rapidly bobbles up and down in the airflow of a calibrated narrow funnel. Its average height (as it bobbles) is raised or lowered by the speed of the air leaking/rushing past it. In this case it is not a closed system.
or, you can go on ebay, search for 'manometer' and get a digital, dual port differential manometer for 29.99 shipped.
RE: Need some advice on APAP Range settings
Thanks palerider for explaining. Learn something new everyday!
RE: Need some advice on APAP Range settings
Yes, thanks palerider for the information. I didn't use the right terms, although I was headed in the right direction. I haven't thought about pressure measurements since I serviced ac and refrigeration systems over thirty years ago.
RE: Need some advice on APAP Range settings
(04-10-2016, 05:00 PM)pupcamper Wrote: Yes, thanks palerider for the information. I didn't use the right terms, although I was headed in the right direction. I haven't thought about pressure measurements since I serviced ac and refrigeration systems over thirty years ago.
most of the pressure changes take place over the period of a few seconds as you inhale and exhale.
my manometer is digital, and updates the readout about twice a second, iirc. it's also got a min/max pressure capture.
I wish it was higher resolution and had a data output, but, it is what it is
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