Fig. S3.

The Cyberonics vagus nerve-stimulation system. The implanted system has two components: a bipolar lead containing two helical coil electrodes and a helical anchor tether that were wrapped around the cervical vagus nerve, and the pulse generator that is placed within a subcutaneous pocket in the chest wall. (A) Schematic diagram of the system. The lead was tunneled subcutaneously from the neck to the pulse generator and inserted into the lead attachment port on the generator. (B) Images of the helical electrode and pulse generator.