Transcutaneous electrical nerve stimulation (TENS) devices use two side-by-side electrodes (positive and negative), on the same plane (i.e., the same side of the skin), causing electrical energy to flow between electrodes.  To reach a target nerve with TENS requires stronger voltages to produce enough spill-over current to leak through surface resistance (of the stratum corneum) and penetrate layers of dermal-epidermal tissue.

TENS devices can be effective for pain relief, but the stimulation of cranial nerves requires a higher standard due to their direct connection to the brain and nervous system, and hence a greater need for safety.For the stimulation of cranial nerves, conventional 2-D TENS electrodes are both unsuitable and risky, because 2-D TENS devices require higher energy to reach nerve targets.

WARNING: NEVER use TENS devices or TENS electrodes on the Neck, Head or Face.  TENS devices output much stronger electrical current than should ever be used to Stimulate the Vagus or other nerves in the Auricular Nerve Field.  Serious neurological injury and skin burns may result. EXCEPTION: TENS may be placed close together on the back of the neck only.

CAUTION: Neck electrodes may send electricity through the heart.