Cryostasis chamber

A cryostasis chamber, also known as a cryochamber, a cryostasis tube or a cryotube, was a storage device used to preserve living beings at cryogenic temperatures for later revival.

Over three hundred people, including Amelia Earhart, were abducted from Earth in 1937 and brought to the Briori homeworld in the Delta Quadrant to work as slaves. Earhart and seven others remained in cryostasis on the planet until they were revived by the crew of USS Voyager in 2371. 

Cryotubes were used on sleeper ships from late 20th century Earth. After warp-capability was achieved, the need for cryostasis became obsolete.