Stella Courtney
From Tardis Wiki, the free Doctor Who reference
Professor Stella Courtney was a neuroscientist who dated Jack Harkness for five weeks in the 1970s.
In 2009, Gwen Cooper and Ianto Jones called Stella in to save Jack and other victims of a phone-line effect. She suggested using an MRI in St Helen's Hospital to create an electromagnetic wave which would awaken them. (AUDIO: The Dead Line)