My feedback loop is a small object, it looks like alarm clock, and it can show some information on the screen, such as time, temperature, humidity and air quality index. in the center of the screen, there has a progress bar, it can show oxygen levels and carbonic oxide levels. this object can give an alarm when the levels is lower.
in the Air, there has only 20% oxygen, especially. the amount of oxygen are reduced while you are in the bath. So i think this object is very important that you can know the oxygen levels or carbonic oxide levels in you room.