Neural transponder

A neural transponder is a device capable of generating a neuro-electric field, linking the brain patterns of separate individuals, allowing for instantaneous access to information stored in an individual's mind. 

The group of former Borg drones known as "the Cooperative" constructed a portable neural transponder, capable of re-linking the brain patterns of a small number of their members. Using this device in combination with a neural transceiver, they were able to heal Commander Chakotay, first officer of the USS Voyager, who had sustained serious injuries upon being fired upon with a particle weapon in 2373. Later, using the residual link they maintained with Chakotay, they influenced him to reactivate the neuro-electric field generator of a derelict Borg cube, and redirect it towards the planet, allowing the Cooperative to forcibly establish a neural link amongst the planet's entire population.