The Britain's Got Talent judge believes through positive thinking he can make a difference to people's lives and said it was speaking as his Knight Rider character Michael Knight that brought the boy out of his coma.
He said to BBC Radio Five Live: 'The upside of being in showbiz is being able to hold the hand of a kid who is dying, you know.
'I did a tape for a kid saying: 'Hey buddy, it's Michael Knight, Michael Knight, come on, wake up, wake up, wake up.'
'The phone rang and they said: 'Remember that kid you did the tape for that was hit at that crosswalk in London? Well we played the tape for him and he came out of the coma.''