An oxygen concentrator is a medical device designed to provide a concentrated stream of oxygen to a patient. The air from an oxygen concentrator has a higher concentration of oxygen than the surrounding air, but the unit does not depend on the use of oxygen tanks. There are a number of reasons to use an oxygen concentrator with a patient, and these devices are subject to varying degrees of regulation, depending on where they are used. With an oxygen concentrator, the unit enters air into a chamber that absorbs nitrogen. The oxygen -rich air is guided through a pipe to the patient, while nitrogen is ventilated harmlessly. Depending on the size of the unit, it can filter and concentrate varying amounts of air per minute. Oxygen concentrators can be used instead, as seen in hospital rooms, and several companies also do laptops that can be used by people while traveling or wanting to be upbeat.