Using molecular sieve technology, the Inogen One oxygen concentrator takes in-room air, filters out the nitrogen, and delivers pure oxygen to the patient. The device can be plugged in anywhere -- at home, in the car, or even on a plane -- or used on the go with a rechargeable lithium ion battery that lasts up to three hours. Founders Brenton Taylor, Ali Perry, and Byron Meyers developed the idea for the Inogen One after Perry's grandmother complained about the inconvenience of her old machine.