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)

Behind the scenes

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