Tri-laser connector

From Memory Alpha, the free Star Trek reference

The tri-laser connector was a medical device in use during the 2260s. Tri-laser connectors were found in the surgical kit of a medical tricorder. The device is used to finely join individual nerve connections

A tri-laser connector was used in an operation to return Spock's brain to his body. (TOS: "Spock's Brain")

Laser technology
Tools: autosuture • bone-knitting laser • laser beacon • laser cannon • laser drill • laser scalpel • laser scanner • laser torch • laser welder • microscope laser • miniature laser • nanopulse laser • tri-laser connector
Weapons: Artonian laser • laser cannon • laser detonator • laser pistol • pulse laser • x-ray laser
Other: laser fusion initiator • laser micrometer • LIDAR • optic nerve laser welding