A bio-electric field generator was a medical device utilized by Starfleet in the 24th century.
In 2373, The Doctor utilized a bio-electric field generator, along with a subdermal scalpel 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")