Nerve stimulation during thyroidectomy has been described in the 1940s, where palpation of the larynx during recurrent laryngeal nerve...
Medtronic NIM-Response 3.0 Nerve Monitor
The Medtronic NIM monitor is an example of a continuous intraoperative nerve monitor, with applications in a number of Head and Neck Cancer surgeries. For thyroidectomy, the NIM EMG endotracheal tube provides both an airway for intraoperative ventilation, as well as nerve monitoring for the vagus or recurrent laryngeal nerves. It does so by detecting movement of the muscles of the larynx.
Cross bands on the tube guide its placement during intubation, and should be placed at the level of the vocal cords. After identification of the recurrent laryngeal nerve, confirmation can be achieved via stimulation with the NIM probe, and evaluation of vocalis muscle activity response on the monitor.
The continuous monitoring system will also notify the surgeon of a change in nerve status in the event of an accidental transection, at which time re-anastomosis can be attempted. Immediate identification of nerve injury can potentially save the patient from another dedicated surgery for nerve repair.