A quick read was that Massimo uses signal processing to improve accuracy. These sort of patents are difficult because it is fairly obvious that is the way to improve accuracy, so there needs to be something clever in the processing. It may be that Massimo made a mess of the patent and made it for devices only in contact with the user.
Yes, basically you are healthy. Sitting in front of a computer there is no reason that someone healthy should be short of oxygen. Feeling that you aren’t getting enough air in when you breathe is likely a good sign that your blood oxygen is low. Maybe try it after running or strenuous walking.