She continued to be given oxygen three times a day until she died.

CNN: PASSAGE

Macgillivray, who can struggle to walk, sat throughout his six-day trial breathing oxygen through a tube.

BBC: Life sentence for murderer who has five years to live

You may need up to three treatments on the first day of hyperbaric oxygen therapy, followed by twice-daily treatments for up to five days.

CNN: Gangrene

But what's novel about the CEAC design is that it incorporates a bio-regenerative life-support system -- the kind of technology that could one day not only feed an outpost on the moon or Mars, but also provide it with oxygen and recycle its water.

CNN: To boldly grow where no one has grown before