"I'm new to this group... I was diagnosed with COPD back in the 90's.. I stopped smoking in 1996.. I started pulmonary rehab in 2012 and started using oxygen when on the treadmill in 2013.. The next year I went on oxygen 24/7 with a vpap machine at night. I used a portable concentrator to travel outside the house and the US for 3 years. Am now using tanks, and a home concentrator... 3 lpm pulse rate when I use the tanks and the same rate with the home concentrator."