Myelin regenerator

A myelin regenerator was a 24th century medical device used to regenerate the myelin sheath of a nerve.

In 2373, The Doctor used the myelin regenerator on Tom Paris after he was attacked by members of the Swarm species. 

Later that year, Kathryn Janeway used this device on her arm after she was bitten by a macrovirus that had infested USS Voyager.