Subdermal scalpel
The Doctor utilizes a subdermal scalpel on Ensign Kim
A subdermal scalpel was a medical device utilized by Starfleet in the 24th century.
In 2373, The Doctor utilized a subdermal scalpel, along with a bio-electric field generator and a cellular regenerator, to perform a spinal shunt on Ensign Harry Kim, who had been severely injured in an alien attack. Although The Doctor was successful in saving Kim's life, he failed to save the life of Ensign Ahni Jetal, who had also been injured in the attack. (VOY: "Latent Image")