Central vs Obstructive Apnea - EERS Device and Trial

[ChadBSr]

You have some problems with your theory. What if you have a spouse that doesn't need/want CO2?  What if your exhaust equipment fails?  Also are you sure you're calculating the fact that the EERS is constantly vented? I think you're exaggerating the amount of CO2 we're talking about. You should scroll up and find the links to the EERS studies (or visit this board's wiki) that have been published by doctors.

[sim62]

You have some problems with your theory. What if you have a spouse that doesn't need/want CO2?  What if your exhaust equipment fails?  Also are you sure you're calculating the fact that the EERS is constantly vented? I think you're exaggerating the amount of CO2 we're talking about. You should scroll up and find the links to the EERS studies (or visit this board's wiki) that have been published by doctors.

Sorry my advice to keep high levels of CO2 in your room was a joke. But my calculation was not. I do not want to dig into large scientific texts on this subject. If you would point me where I am not right I would appreciate it. 

Also are you sure you're calculating the fact that the EERS is constantly vented? 

As far as I can understand the operation of your Y-system, the air exhaled into the lower tube (attached to the mask) remains there until you re-breathe it. Only the V-shaped part is vented. I supposed that the combined volume of the lower tube and your mask (that also remains filled with exhaled air) is 50 ml.

[ChadBSr]

That's incorrect. The entire tube is vented just like whatever mask you are using. Your joke is discussed in a study in one of the links I have posted on the thread. This is not a joke it is an actual medical device that has been used to help people with high loop gain/ TECSA. One of the main purposes of this thread is to show the safety of EERS and dispel the fear caused by jokes and uneducated assumptions. Again, I would suggest you read through the thread.

[sim62]

Just one more question if you please. 

The entire tube is vented just like whatever mask you are using

 Whatever mask I am using is flushed with fresh air that removes the exhaled air before the inspiration act. In this case I can not see how you manage to re-breathe any significant amount of exhaled air. 

Now let us look at this:
https://www.apneaboard.com/wiki/index.ph...ace_(EERS)

 Mack's putty is placed on outside of exhalation port. // Without adding the Corr-a-Flex segment, the nasal mask tube (16-inches x 15 mm) provides about 70 mL of dead space. Standard Corr-a-Flex is in 6-inch (15.24 cm) segments which has about 58 mL of dead space. (The volume of the tubing is V = Pi * r squared * length and 22 mm diameter tubing has about 3.8 mL/cm with 15 mm diameter tubing being about one-half (0.7) of that volume).

I assume that the mask exhalation port is blocked with putty. In this case the mask and part of tube are not vented. I think that "dead" means exactly non-vented volume. This volume is filled with exhaled air on exhalation, and this amount of exhaled air is re-breathed upon inhalation. And this volume is 128 ml (!). Am I missing something here? It's not about theory, just design and operation.

[SarcasticDave94]

My basic understanding is the dead space is being added to. It moves the vent further away.

[sim62]

SarcasticDave94,

AFAICS my understanding is same as yours. In this case, an unormous amount of exhaled air (~ 1/4 of the total inhalation volume) is being re-breathed. May be it works for someone, I just would like to know that I understand it right. ChadBSr apparently says something different.
Let us put the question this way:
1. Is the dead volume vented?
2. Is it filled with exhaled air upon exhalation?
3. Is all of that air re-breathed upon inhalation?

[sim62]

ChadBSr,

your system seems to be different from the one I referred to above. If so, could you please give me a link where it is described. That could be easier for you and would be more informative for me. 400 ml EERS defintely can not be dead (non-vented) volume. This gives me a clue that exhaled air is mixed with fresh air in a reservoir, and the mask is vented with mixed air.

BTW in the article cited above (if I understand it correctly) using 128 ml of dead volume is equivalent to breathing the ambient air containing about 9,000 ppm CO2.

[ChadBSr]

There is a vent that constantly vents air regardless of how big the "dead space" is. The second you stop breathing in it is being pushed out the vent. Actually most of time we are breathing a small enough volume that some of it is being vented simultaneously as we breathe. Again, you can view the medical studies where they actually monitored the end tidal co2 levels of patients. You are over calculating the amount of co2 actually being rebreathed, which by the way is NORMAL. We are not increasing to unnatural levels. We are counter acting the unnatural co2 wash out of the cpap machine.  The only difference with my setup is the Y fitting and nothing after the Y counts as dead space because it isn't rebreathed. I can and have placed a 6 ft hose after the Y with zero change. The air from the CPAP will go to me and out the Y because the pressure is lower there. When I breathe in I get air from the CPAP because that's the higher pressure. I rebreathe a small amount of air left in the tube before the Y

[sim62]

As I have already said I am considering only the physics and maths. One liter of water at normal conditions will weigh one kilogram. Nobody's thoughts or words can override that. Above I presented the calculations for the system described in https://www.apneaboard.com/wiki/index.ph...ace_(EERS). If you see a mistake please tell it to me. 

Your mask exhale valve is open, isn't it? Then the above calculations are not applicable. But tjen I do not quite understand how you get that "small amount" of exhaled air. My mask is connected directly to the CPAP machine with a 2 m hose. Am I also rebreathing that small amount? In other words: what would change it you would remove the Y-joint and connected your CPAP machine to the hose at that point?

[ChadBSr]

Your vent is at your mask. When you exhale it goes out of your mask vent at a specific rate. Your unmodified mask vents all of your exhaled breath. So much that you have less CO2 than someone breathing with no CPAP. My vent is farther away. It vents at roughly the same rate but a very small amount doesn't get pushed out, an amount closer to normal breathing.

This would all be much easier if you just read the wiki.

What's the exhaust rate of your mask? What's the exhaust rate of my whisper swivel vent? If you haven't looked those up then please don't pretend you're simply presenting basic math.

I'm happy to explain the setup but I don't want to argue with someone who doesn't even have enough interest to look at the very detailed build write ups in the wiki.

https://www.apneaboard.com/wiki/index.ph...ace_(EERS)