I don’t understand the use of such a complicated device. Apparently, you can order a suicide kit over the internet that’s a drawstring bag with a small cylinder of (I think) nitrogen. There’s no sensor in the lungs for nitrogen like there is for CO2. An overload of CO2 will create all sorts of discomfort. Nitrogen displaces the oxygen, and you pass out and suffocate without any discomfort.
I once worked in a huge industrial building with a controlled access work area that had a code-locked door. On the other side of the wall was a gigantic nitrogen tank. Some pipes that brought nitrogen through the controlled access area to a place where it was used began to leak. Everyone in the room died apparently unaware there was a problem. Someone opened the door and saw everyone on the floor and fortunately didn’t go in. My understanding is just a couple of breaths, and you would pass out.
Consider our normal air is already about 78%, 21% O2, and rest, trace amounts of co2 and other gases.
Kind of shows what a racket nitrogen filled tires are. Regular air already puts 78% nitrogen in your tires.
I'm aware of a case of a worker in a processing plant who was responsible for cleaning the inside surfaces of a very large tank. He wore an oxygen mask to protect from toxic fumes.
He entered the tank to work one time and quickly passed out. His co-workers saw that he had a problem and dragged him out and removed his mask. He very quickly recovered and went back to work.
He passed out a second time and required rescue again. Only then was it recognized that his mask had been plugged into a source of nitrogen instead of air. After that they decided that maybe it wasn't a very good idea to use the same connectors on both nitrogen and air.
The guy was very lucky to survive.
I remember reading of a similar death when men went into a sewer and died of sewer gas.