Stasis chamber

A stasis chamber was a machine used to keep its occupant sedated and alive.

The Tenth Doctor instructed Martha Jones to put him in a stasis chamber, minus 200 degrees, to freeze the invading system out of him. (TV: 42)

Elliot Northover was kept in a stasis chamber after he was taken by the Silurians. (TV: Cold Blood)

The Fisher King planned to place himself inside a stasis chamber and have his coordinates transmitted to his people so that he could be recovered. The Twelfth Doctor tricked him into leaving the stasis chamber behind, and then used the stasis chamber himself to return to the future. (TV: Before the Flood) This stasis chamber would later be discovered by the crew of the Drum with the Doctor's help. (TV: Under the Lake)

Behind the scenes

 * The stasis chamber from the episode 42 is the (redecorated) MRI machine from Smith and Jones.
 * In the invalid source Attack of the Graske, the Graske kept its Changelings in stasis chambers.