U.S. Food and Drug Administration
https://www.fda.gov/consumers/consumer-updates/pulse-oximeters-and-oxygen-concentrators-what-know-about-home-oxygen-therapy
Pulse Oximeters and Oxygen Concentrators: What to Know About At ...
Feb 19, 2021 ... ... oxygen concentrator at home unless it has been prescribed by a health care provider ... medical purposes. If you are using a pulse ...