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Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 1:24 am
by palerider
USMCVet wrote:
Sun Feb 25, 2018 12:48 am
So we have a basic manometer which is U shaped and symmetrical. We fill it with water. At this time I see it like a scale. You have equal atmospheric pressure on either side because diameter of tubing is the same which means the amount of water on each side is the same. So both sides being equal you can apply a steady pressure to either side and get the same result. However if you have the same tubing on either side but a lot more water on one side which equals more weight for atmospheric pressure to fight you won't get the same result if you add the atmospheric pressure to either side.

If you have a lot more pressure on one side (side with more water which weighs more then air) then the other then the scales aren't equal.
I do believe you're wrong.

Take your basic idea, put a gallon bucket on one side, with a 1/8th" tube coming off the bottom, and up the side. you've now created your manometer with unequal size tubing.

what's gonna happen when you put 10cm/h2o pressure on one side or the other?

how're you gonna get water into the cpap? how're you gonna keep water from blowing OUT of the cpap into the big container.

Your dog bowl example works by the water pulling a vacuum in the sealed bottles, which holds the water up in those, then when it gets too low, there's enough room for bubbles to enter the lower opening and release some of the vacuum, thus releasing water.

This works well, because it's a static system, no pressure variances.

I'm not saying that doing it with the varying pressures of cpap would be impossible, but it's going to be much harder to engineer reliably. Basically, if this was *easy*, it'd already be widespread... among the small percentage of people that need it.

Someone did do something similar in the past, but it involved, (iirc) multiple tubes, a large sealed jug, and precise height control between the cpap and the auxiliary jug to make it work.

An alternative would be to put a time of flight sensor in the top of the water reservoir, and a peristaltic pump to refill the chamber automatically.... but $$$

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 2:25 am
by USMCVet
Can you agree that with a single tube set with my preference of diameter I could create an auto fill reservoir to fill a CPAP humidifier reservoir for at least 2 days without refill despite a typical pressure amount ( let's say 15 cm h20?).

Also please refer to your post. A manometer with a gallon of water on one side and not the other is not a manometer.

My point is having more water on one side then the other will tilt the balance in our favor so to speak.

Again without thinking things through and giving you a chance to see things from my point of view what's your opinion.....

Imagine a U shaped tube with equal parts of water on each side. Things are in perfect equilibrium...... Now one one side you add let's say 500% of water then is on other side?

If both sides have tube filled to brink then the side without extra water will overflow. If you argue with this then I'm done talking with you or willing to bet serious cash lol. With that basic principle I win. Only matter of contention is how big does my supplemental reservoir have to be?

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 3:00 am
by palerider
USMCVet wrote:
Sun Feb 25, 2018 2:25 am
Can you agree that with a single tube set with my preference of diameter I could create an auto fill reservoir to fill a CPAP humidifier reservoir for at least 2 days without refill despite a typical pressure amount ( let's say 15 cm h20?).

Also please refer to your post. A manometer with a gallon of water on one side and not the other is not a manometer.
Er, yes it is.

https://www.shutterstock.com/video/clip ... blood.html

A mercury manometer, specifically, a mercury sphygmomanometer, measuring the pressure it takes to push a column of mercury up... which is why your bp is still measured in mm/hg.

You'll note that there's a larger vessel on one side, compared to the other, so that it's more compact.

The principles are similar.

All your 'larger surface area' is going to do is reduce the amount of distance the larger surface area travels in response to the pressure.
USMCVet wrote:
Sun Feb 25, 2018 2:25 am
My point is having more water on one side then the other will tilt the balance in our favor so to speak.

Again without thinking things through and giving you a chance to see things from my point of view what's your opinion.....

Imagine a U shaped tube with equal parts of water on each side. Things are in perfect equilibrium...... Now one one side you add let's say 500% of water then is on other side?

If both sides have tube filled to brink then the side without extra water will overflow. If you argue with this then I'm done talking with you or willing to bet serious cash lol. With that basic principle I win. Only matter of contention is how big does my supplemental reservoir have to be?
How much money do you want to lose? a *simple fact* of water is that it will find the same level, absent pressure differentials.

Your theory is proven false by *any* watering pitcher.
Image

No amount of water poured into the large end will result in water coming out the tube. What you have there is what you basically described.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 3:16 am
by USMCVet
palerider wrote:
Sun Feb 25, 2018 3:00 am
USMCVet wrote:
Sun Feb 25, 2018 2:25 am
Can you agree that with a single tube set with my preference of diameter I could create an auto fill reservoir to fill a CPAP humidifier reservoir for at least 2 days without refill despite a typical pressure amount ( let's say 15 cm h20?).

Also please refer to your post. A manometer with a gallon of water on one side and not the other is not a manometer.
Er, yes it is.

https://www.shutterstock.com/video/clip ... blood.html

A mercury manometer, specifically, a mercury sphygmomanometer, measuring the pressure it takes to push a column of mercury up... which is why your bp is still measured in mm/hg.

You'll note that there's a larger vessel on one side, compared to the other, so that it's more compact.

The principles are similar.

All your 'larger surface area' is going to do is reduce the amount of distance the larger surface area travels in response to the pressure.
USMCVet wrote:
Sun Feb 25, 2018 2:25 am
My point is having more water on one side then the other will tilt the balance in our favor so to speak.

Again without thinking things through and giving you a chance to see things from my point of view what's your opinion.....

Imagine a U shaped tube with equal parts of water on each side. Things are in perfect equilibrium...... Now one one side you add let's say 500% of water then is on other side?

If both sides have tube filled to brink then the side without extra water will overflow. If you argue with this then I'm done talking with you or willing to bet serious cash lol. With that basic principle I win. Only matter of contention is how big does my supplemental reservoir have to be?
How much money do you want to lose? a *simple fact* of water is that it will find the same level, absent pressure differentials.

Your theory is proven false by *any* watering pitcher.
Image

No amount of water poured into the large end will result in water coming out the tube. What you have there is what you basically described.
So a J shaped tube is the same as I am talking about. More pressure from one end will equalize with the other.
So considering a machine provided to me for free I am willing to bet $100 I can make it work.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 3:18 am
by palerider
USMCVet wrote:
Sun Feb 25, 2018 3:16 am
So considering a machine provided to me for free I am willing to bet $100 I can make it work.
Use the one you've got. Make it work.

If you do, there'll be some folks that are happy about it.

I wish you luck, but I predict that it'll be more complicated than you believe.

Bear in mind, you aren't looking for pressure equality, you're looking to refill one container from the other, with varying pressures on the first.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 3:22 am
by USMCVet
palerider wrote:
Sun Feb 25, 2018 3:18 am
USMCVet wrote:
Sun Feb 25, 2018 3:16 am
So considering a machine provided to me for free I am willing to bet $100 I can make it work.
Use the one you've got. Make it work.

If you do, there'll be some folks that are happy about it.

I wish you luck, but I predict that it'll be more complicated than you believe.
I do have an extra machine that I gave to a friend Friday for proof of concept that CPAP works. Again I haven't fully thought it out but I think I can make it work for $50ish. It won't be pretty but I think I can make it work.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 3:52 am
by palerider
USMCVet wrote:
Sun Feb 25, 2018 3:22 am
palerider wrote:
Sun Feb 25, 2018 3:18 am
USMCVet wrote:
Sun Feb 25, 2018 3:16 am
So considering a machine provided to me for free I am willing to bet $100 I can make it work.
Use the one you've got. Make it work.

If you do, there'll be some folks that are happy about it.

I wish you luck, but I predict that it'll be more complicated than you believe.
I do have an extra machine that I gave to a friend Friday for proof of concept that CPAP works. Again I haven't fully thought it out but I think I can make it work for $50ish. It won't be pretty but I think I can make it work.
I look forward to your prototype. (seriously).

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 6:08 am
by lamar2217
This discussion sounds like a solution looking for a problem. Check the water level daily.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 8:01 am
by D.H.
palerider wrote:
Sat Feb 24, 2018 10:23 pm
I really don't want my cpap waking me up in the middle of the night...

I use it so I can sleep through the night, and not get waked up to deal with 'water' issues. :cough:
That's why you would need the option to disable this feature. However, the heating element would still cut out so I don't have to smell that burning smell!

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 11:47 am
by Goofproof
USMCVet wrote:
Sat Feb 24, 2018 11:03 pm
Goofproof wrote:
Sat Feb 24, 2018 10:53 pm
lilly747 wrote:
Sat Feb 24, 2018 10:33 pm
I ran out of water last night. I never ran out of water on my S9 VPAP. So why not make the water tank capable of holding enough water...stupid design flaw.

Guess I will try turning the temp down. Right now it is on auto.
A five gallon HH tank won't fit in the overhead luggage storage, We have XPAP users trying to travel with 5 lb XPAP's complaining it's too much trouble. I'm waiting untill my new XPAP has a 55 inck HD Led T.V. built in with SAT T.V., and A/C! :lol: Jim
Ok what about a port on the side of machine with a cap that has lanyard so you can't lose it. When at home you can have a 5 gallon or less humidifier tank that connects to CPAP via hose to the port. That way it autofills humidifier reservoir. Kind of like they have those dog water bowls where to screw in two liter bottle of water to keep bowl topped off.

Problem solved.... Next problem please lol
Great idea but do to air pressure (In and Out) it won't work, the hamster will drown. Static pressure, it in doable, variable no, it will keep filling. Plus Granny probably won't be able to handle the 5 gallons of water.

We need a Robot, to take over for the users that can't control their environment, figuring out how HH's work, and the fact the warmer you set them the more, and the more air flow water they will use. As so the fact, the air at a set temp, can only hold so much water before rain-out happens. You can try to fool Mother Nature but in the end, She Rules.

Sure the ability for the XPAP to control everything you should be easily do for yourself, could be added, but I hope they add the T.V., Sat Service and A/C, first, I'm sure your or billfold INS company won't mind the added cost.

As far as the robot, I don't know when "Nurse Clank Clank" will be available or her cost or if Medicare or INS will cover her! :roll: Jim

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 12:11 pm
by USMCVet
I'm not sure if my arguments are sound but I do think I can make it work with the basics I stated. I don't know if my machine is even really mine since the VA gave it to me so I will see if I can find one to experiment on.

How will we determine success or failure?

Even if it doesn't work will be fun. Now I make no promises of it looking pretty lol just proof of concept.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 12:42 pm
by lilly747
USMCVet wrote:
Sun Feb 25, 2018 12:11 pm
I'm not sure if my arguments are sound but I do think I can make it work with the basics I stated. I don't know if my machine is even really mine since the VA gave it to me so I will see if I can find one to experiment on.

How will we determine success or failure?

Even if it doesn't work will be fun. Now I make no promises of it looking pretty lol just proof of concept.
If you can make it work, maybe you can sale the concept to ResMed and they can make it pretty.... :lol: :lol:

Last night I got up at 2am and refilled the damn thing, but this is not going to work for me long term..........so

In the mean time I lowered the HH. Would turning down the tube temp also help..does not sound like it would, but I am no engineer... :mrgreen:

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 1:50 pm
by palerider
lilly747 wrote:
Sun Feb 25, 2018 12:42 pm
Would turning down the tube temp also help..does not sound like it would, but I am no engineer... :mrgreen:
The tube temp has no effect on the water temp, which is what controls how fast it evaporates.

So, no.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 2:50 pm
by USMCVet
Oh and to address the watch pitcher . Think of it like a gravity fed water tower.

Here is a video that shows one possible way to do it.

https://youtu.be/Q4OkB38pwYk

20 cm h20 equals 0.2844 PSI.

So we would need a higher psi going into humidifier to prevent backflow right? So 8 inches of h20 equals 0.2887 . So really it's all a matter of height of water over humidifier reservoir.

Re: adding water detection to future cpap/bi-pap machines

Posted: Sun Feb 25, 2018 3:00 pm
by TedVPAP
If I understand what some are talking about, it seems like some people want a larger water reservoir so that they don't have to fill-up so often. To do this all that is needed is a sealable reservoir that can handle low pressure (e.g., plastic soda bottle), two pieces of tubing, and four tube fittings.

Attach the tube fittings towards the top (above the water line) and the bottom of the existing humidifier reservoir and the supplemental reservoir - the fittings can not leak so use silicone. Join the two reservoir with the tubing. The top tubing will ensure air pressure in both tanks are the same so the water level will also be the same.