Has anyone here tried using an oxygen concentrator to increase their productivity? I can get the CO2 level in my room to around 580 with a comfortable temperature, but I never feel quite as clear-headed as when I'm working outside. I'm wondering if getting an oxygen concentrator that gets my effective CO2 level to ~400 would carry any risks or downsides that I should know about. For example, one thing I'm learning is that these machines can be loud, so I'd need to consider whether the productivity gain from increased oxygen would be offset by increased ambient noise.
Update: Here are a list of things I think I'll try based on comments: 1. oxygen cylinder, 2. CO2 scrubber, 3. oxygen concentrator, 4. air exchanger.