Thanks to the field of medicine’s great advancements, the oxygen concentrator today are compact, small, quiet and lightweight, but still provide the utmost compliance and high performance. Older oxygen concentrators are bulky and heavy, making it difficult for patients requiring oxygen therapy while traveling or outside their home. Today, you can choose from at home stationary concentrators and portable oxygen concentrators (POCs), which can go wherever you go easily. concentrator definition: An oxygen concentrator is a type of medical device used for delivering oxygen to individuals with breathing-related disorders. Individuals whose oxygen concentration in their blood is lower than normal often require an  concentrator to replace that oxygen. Generally, you can’t buy an  concentrator over the counter. A doctor must prescribe it after they’ve completed a thorough medical evaluation. The doctors will also typically show the patients how to effectively use these concentrators while traveling and in their home.