Restoration field

A Restoration Field was a device that could stop a person from dying. A restoration field was added to the Pandorica so that the Doctor would be unable to escape by dying. It was instead used by the Doctor to reanimate the nearly dead Amy Pond. It later reanimated the Stone Dalek and the Doctor used it to revive himself when the Dalek shot him, nearly killing him. With the universe destroyed, the Doctor planned to use the restoration field to "reset" the universe. By flying the Pandorica into the heart of the TARDIS's explosion, the light was spread throughout the universe at every point in time, resetting the universe and also reversing the total event collapse. (DW: The Big Bang)