Electrode pad

A Borg with electrode pads
An electrode pad was a piece of technology used for medical purposes. It was placed on a lifeform and could determine and transfer biometric data including vital signs to a computer which displayed these information on a monitor.
In 2153, electrode pads submitted biometric data about pulse, EEG, cell rate, and respiration of a Borg drone to a computer terminal. (ENT: "Regeneration")