Method Proposed mask to replace exit bag (for critique and / or suggestions

[color_me_gone]

I am researching an alternative to the oven roasting bag over head, for inert gas asphyxiation, aka Exit Bag.

Warning: this is a proposed alternate method for critique and / or suggestions!
This has NOT yet been built or tested!

Figure 1:
3M 6100 Half Facepiece Respirator $17
Figure 2:
Same Respirator shown from face side (shown with unneeded filter cartridges attached)
Figure 3:
SlimStyle CPAP Hose Tubing - 6 ft $12 Qty:2
Also available in 4 ft length for $10
Figure 4:
Heavy duty contractors trash bag
3 mil plastic thickness, 40 to 60 gallon size, available many places, 1 required

I think inert gas asphyxiation is a wonderful way to go, second only to dying in your sleep.
But I find the oven roasting bag over my head to be offensive, silly and undignified.
It also adds to terror while waiting to become unconscientious.
That terror provokes your survival instinct to remove the bag before becoming unconscientious.
That was demonstrated by TiredHorse in his three trials on his thread: Exit bag and inert gas megathread

The respirator contains three air valves. Two are intake, one is exhaust.

When inhaling, the intake valves open, and allow air to enter the nosepiece through the two holes located on either side of the nosepiece. The exhaust valve is closed, preventing outside air from being drawn in. When used for its intended purpose, the intake ports have filter cartridges attached to provide filtered intake air.

When exhaling, the intake valves close, preventing exhaled air from entering the filter cartridges. The exhaust valve opens, allowing exhaled air to vent to the atmosphere through the exhaust port located on the front of the nosepiece.

The CPAP hoses are used to bring non-pressurized pure inert gas residing in the plastic bag (figure 4) to the intake ports of the respirator. Flow in these hoses is drawn by natural respiration. All inert gas used in this design passes through the lungs. The respirator valves deal with the elimination of CO2 to the atmosphere. The valves also handle the initial purge, so that step is eliminated.

I have one of these masks. It fits very comfortably over the nose and mouth. Soft rubber seals provide an air tight seal to the face without discomfort. The straps hold it securely, so no worry of it becoming dislodged during the process. The design will work in any body / head position. I image a deeply reclined or lying flat position to simulate drifting off to sleep and never waking up.

The purpose of the large contractor bag is to convert a regulated gas flow into a standing supply of gas waiting for aspiration. This design uses the same inert gas tank, regulator valve and hose as the exit bag. The differences are that this hose is input to the contractor bag, and the flow rate is set to match the respiratory minute volume of a typical human.

Respiratory minute volume is the volume of gas inhaled or exhaled from a person's lungs per minute.
https://en.wikipedia.org/wiki/Respiratory_minute_volume
Although minute volume can be viewed as a unit of volume, it is usually treated in practice as a flow rate.
Typical units involved are 0.5 L × 12 breaths/min = 6 L/min.
A normal minute volume while resting is about 5–8 liters per minute in humans.

The bag is sealed to the input and output piping. The bag always contains pure gas. I would like to keep this at a concept level, so please don't ask about how all the pipe is secured to the various places.

Thanks, in advance, for your thoughts, opinions, and suggestions.

Love and Hugs,
Jerry aka color_me_gone

 

[TiredHorse]

Actually, having the bag over my head wasn't at all terrifying. It was pretty inconsequential to my failures. IG takes a while, even with a mask, and I think my failures were due to my inability to breathe deeply rather than the method (impending death, even when it is hoped for, is quite frightening enough, thank you very much).

Let me start with this: I have 3M respirators in my shop, both the half-face you show and a full-face, and I still decided to use a turkey-bag. I've only read of a single successful IG suicide where a mask was used, and that was a full-face scuba mask with the gas line plumbed straight in from the regulator --not a bodge job, but pretty professional. IIRC, the guy who used it to die was a certified scuba diver, so he knew his business. Scuba --and the scba systems I used as a firefighter-- is what's called a "positive pressure" system, where the gas is pressurized to be constantly flowing into the mask against the pressure of your exhalations. Respirators are not: your exhalations will draw from an outside source as needed, but any CO2 build up will not be flushed away so quickly as you might think. I've actually gotten a dose of hypercapnic alarm during a long session in my full-face respirator, when I was breathing shallow enough to not trip the flapper valves, and thus didn't recharge the fresh air in the mask so quickly as I should have. A turkey bag works as a de facto positive pressure system, flushing excess CO2 out around the neck elastic.

So in the theoretical, 1) I think you would have difficulty making and adequately maintaining a seal to create the IG atmosphere; 2) I think that without a positive pressure system you would be stymied by excess CO2, and 3) I think reliable mechanical connections between hose and mask would be difficult to create (unless you have a shop and are familiar with working with the plastics involved.

But this is just the start of the conversation, and I look forward to hearing what other people have to say. Clearly, since I'm still alive, I'm not so expert in the nuances of the method or the equipment that my techniques could not be improved!

 

[color_me_gone]

Thanks TiredHorse.
Since I have done nothing yet, you are certainly more an expert than me.
My problem is that I have a wife at home, so it is pretty hard to do these things without drawing attention.
And in my state, VA, my wife can have me sent to mental ward lockup without my approval.
Already happened once in the early 90's.
Pretty hard to get gas without suspicion.

 

[TiredHorse]

You're welcome --but I fear I may have been too discouraging on a thread dedicated to the theoretical. I'm sorry if I was.

I would note that an exit bag made from an oven bag is far less conspicuous than you might think. Mine lives in a sandwich ziplock in a shadowed corner of my bookshelf, and it would be a simple thing to tuck it out of sight in a clothes drawer if I still lived with someone. The gas cylinder would be more difficult to obscure, if I did not live alone. Not knowing your situation, I can't really speak to that.

I hope you're able to find a method that works around your restrictions.

 

[color_me_gone]

too discouraging on a thread dedicated to the theoretical

No, I appreciate your input!
I ask for opinions, you gave me your honest opinion, and I greatly appreciate it.

It wasn't the bag part that I was worried about hiding, it is definitely the bottle of gas.
If I had it delivered, it would probably be discovered.
I gave up my car when I retired.
If I need to, I borrow her's.
I would hate to use her car to pick up gas for myself.
Thanks for your support!

 

[ToughLife]

@color_me_gone are you still around? I am building the same respirator setup as you proposed, it seems to me that it will work. I am using a Sundstrom SR 900 half-face respirator, I have tested the intake and exhaust valves and they seal properly.

As for the nitrogen flow rate, I am thinking to set it at 10 lpm which should be more than enough.

Anyone have experience with this kind of setup? Has it been tested?

Any comments are welcome.
Here are some pics:
color_me_gone

 

[ToughLife]

I have some concerns. Since the nitrogen is flowing in constantly, when the reservoir bag is full and the nitrogen keeps coming in, the positive pressure will push open the intake and exhaust valves. When I breath in, would the exhaust valves still stay open due the pressure from the incoming nitrogen? As a result of the open exhaust valves, would the air from the atmosphere that contains oxygen be breathed in as well? Also due to the constant inflow of nitrogen the intake valve stays open, would my exhaled gas that contains CO2 go into the reservoir bag? Please help, I need to know if this will work. I need to ctb soon.

 

[color_me_gone]

@color_me_gone are you still around?

Yup - still here.

I have overcome my desire to ctb, partially with help from this site.

To answer your questions:

1. I have not tested my proposed method, because @TiredHorse response made sense to me at the time. Also, I never had the opportunity to get inert gas due to my wife. Now that I no longer want to ctb is another reason this has not been pursued.
2. Regarding the constant flow of nitrogen in your setup: since since the nitrogen is always flowing in on the inlet valve, and out on the outlet valve, I don't see how CO2 could get into the reservoir bag and I don't see how O2 could come in on the outlet valve. (If you threw a tennis ball into a river, it will travel downstream, as it follows the flow of the water.) Your set-up actually seems to fix the concerns TiredHorse had with my set-up. Your exhaled breath would join in with the N2 flow out the exit valve. I honestly think this would work. You need to test it out first. Follow the procedure TiredHorse used for testing his method.
3. My best wishes to you in achieving your desired end result.

 

[ToughLife]

Thanks color_me_gone.

In theory it works like a non-rebreather mask (NRB), the respirator provides a much better seal on the face so that no air/oxygen will leak into it from the atmosphere. The plastic reservoir bag currently being used is kind of flimsy, I will replace it with an oven bag which is tougher.

Another issue is what flow rate I should set to. Since there is no need to flush out exhaled CO2 as in the exit bag method, I am thinking 8 - 10 lpm is more than enough as we normally breathe in 6 - 8 lpm.

Anyone has experience in NRB mask or respirator? I couldn't find much information on the use of either one.

 

[color_me_gone]

Since there is no need to flush out exhaled CO2 as in the exit bag method

The need to flush CO2 is still present, but the respirator is more efficient at doing so. The volume area is smaller, and the inlet and outlet ports are more controlled than a bag. I agree that the flow rate can be less, but I am not willing to assign a number to the flow rate. That will need to be determined by testing. I am wondering what @Greenberg thinks of all of this, as he replaces TiredHorse as the new expert on this method.

 

[Greenberg]

Thanks color_me_gone.

In theory it works like a non-rebreather mask (NRB), the respirator provides a much better seal on the face so that no air/oxygen will leak into it from the atmosphere. The plastic reservoir bag currently being used is kind of flimsy, I will replace it with an oven bag which is tougher.

Another issue is what flow rate I should set to. Since there is no need to flush out exhaled CO2 as in the exit bag method, I am thinking 8 - 10 lpm is more than enough as we normally breathe in 6 - 8 lpm.

Anyone has experience in NRB mask or respirator? I couldn't find much information on the use of either one.

Interesting setup. Admittedly, the shortfall with the NRB mask (NRB) is the imperfect seal to the face. However, I believe the NRB mask remains superior to what you propose.

The NRB has two one-way valves: One is between the reservoir bag and the mask to allow gas (O2) to flow into the mask when you breathe in but not when you breathe out; the other is at the sides of the mask and allows the exhaled air to escape to the environment.

As noted by @Willyw, you have essentially reinvented the NRB but at a higher cost and complexity.

Attached below is the configuration diagram from Sundström's Half-Mask Air-Purifying Respirator users manual (with the filters). The diagram highlights the inlet and outlet valves which are functionally equivalent to the NRB. What is crucial in your setup is the correct sizing of the bag. A bag too small would not hold enough gas for each breath; a bag too large would contain excessive air at the start of the process.

In regards to the flow rate, it should still be set at 15LPM. This has been established (empirically) as the ideal flow rate for the Exit Bag method. Finally, the hole diameter at the inlet valve would affect your flow rate, as the rate of flow is also a function of the cross-sectional area of the hole.

Please do not misunderstand. I applaud your creativity in improving the design of the NRB. I would suggest that you direct your development efforts in improving the facial seal of the NRB.

Best regards, G


Incidentally, I have noticed that you are using an Ar flow meter. Please do not forget to make the necessary flow rate adjustment.

 

[ToughLife]

@Greenberg thanks for your input. I saw you recommended NRB over exit bag, did you get a chance to test it?

I bought a NRB before but it is too long to fit my face, even if it is not too long the material is not flexible enough to form a tight seal to my face, also the valves do not seal properly. This is the reason why I abandoned the NRB and bought the respirator and modified it.

The bag on a NRB is usually about 1 litre, the bag on my respirator can hold more than 1 litre so it is big enough to hold nitrogen for each breath. If I use an oven bag it will be even bigger. I will suck out the air in the bag before I start filling with nitrogen.

I tested my breathing using water displacement method (exhale through a tube connected to an inverted bottle filled with water with the bottle mouth submerged in water), I only exhaled about 5 lpm. IMHO I think a flow rate of 15 lpm is way too much for this method as there is only a small amount of CO2 left inside the respirator that needs to be flushed out. For the exit bag method, since the exhaled CO2 is trapped inside the exit bag (which is much bigger than the respirator) and mixed with the inert gas, that's why a much higher flow rate is required to flush out the mixed CO2/inert gas. For my respirator method, even at 10 lpm I think the inlet and outlet valves will stay open all the time due to the constant inflow of nitrogen, would that be a problem?

 

[Greenberg]

Honestly, I really do not know how to answer your question without having access to the same equipment you possess and conducting tests. Just bear in mind that the proper flow rate is important.

The NRB fits me well. Nonetheless, I have since upgraded my setup to include a demand valve and anesthetic mask. This new setup uses less gas and offers a snug (and better) fit to my face. With less gas usage, my setup is highly portable. For example, I actually need less than 10cf of gas.

I wish you success in your setup.

Best, G

 

[ToughLife]

I tried to blow air through the tube into the bag, the bag didn't inflat at all, instead the air flowed right out of the intake valve into the respirator. That means the bag will never inflat even with the nitrogen flowing in and no gas will be drawn from the bag when I breathe in, the flow rate needs to be high enough to provide enough nitrogen for each breath. If my breathing rate is 5 lpm I actually breathe in 5 litres in 30 seconds and breath out 5 litres in the other 30 seconds, so in one minute the flow rate should be 5x2 = 10 lpm at the minimum.

Nonetheless, I have since upgraded my setup to include a demand valve and anesthetic mask. This new setup uses less gas and offers a snug (and better) fit to my face. With less gas usage, my setup is highly portable. For example, I actually need less than 10cf of gas.

@Greenberg could you show me your new setup? Where did you get the demand valve and the anesthetic mask? Does the outlet of the demand valve fit right onto the mask? Do you have to use a different regulator to provide higher pressure to the demand valve?