Doctors caring for a Canadian man who has been in a vegetative state for more than a decade say that they have found a way for him to communicate that he is in no pain.

The medical advancement is being touted as the first of its kind in the world.

It happened last June when doctors in London, Ont., used a functional magnetic resonance imaging machine (fMRI) to analyze brain activity patterns in Scott Routley, a patient who suffered a severe brain injury in a car crash 12 years ago.

Neuroscientist Dr. Adrian Owen says he asked Routley to imagine that he was playing tennis if he wasn't in pain or imagine that he was walking around his house if he was in pain.

Doctors knew beforehand that thinking about these movements triggered activity in different parts of the brain, which could then be measured by the fMRI in real-time.

Owen, from the Brain and Mind Institute at the University of Western Ontario, says it was a "landmark moment" for the medical community and can lead to better care for vegetative patients.

Routley is among several vegetative patients profiled in a documentary slated to air Tuesday on the British Broadcasting Corporation.