In a first, an American woman used a suicide pod to take her own life. The process took place in Switzerland. It’s done by pumping in only nitrogen gas, so the person will lose goes dizzy, loses consciousness and eventually dies. Enter futurama memes.
Yeah your drive to breathe is based on CO2 in the blood not O2 level. The higher the CO2 the more you feel the need to breathe. That’s why the capsule uses nitrogen. You don’t respond to the lack of O2 and can still flush the CO2 from your system.