An implanted device for stimulating paralyzed vocal cords

In an attempt to remobilize a unilaterally paralyzed vocal cord, experiments were made in three dogs, using a new implantable device and electrode. Adduction of the paralyzed vocal cord for phonation in synchrony with the intact cord was achieved by an implanted device which electrically stimulated the adductor muscles that was triggered by either signals from cricothyroid muscle or an external telemetered signal which forced stimulation. Difference in sense signals from the cricothyroid muscle between phonation and respiration was used to set the threshold level which triggers the paralyzed side.