Identification of Particular Nerve Compartments and groups of tree electrodes (GTE) Stimuli with intensity ic of a quasi-trapezoidal cathodic phase of 2 mA with frequency of 20 Hz will be delivered for approximately 10 seconds quasi-bipolarly to all 13 GTEs within the cuff. Stimulation of the separate GTE will be performed 1 minute apart. The GTE that elicited the largest change in heart rate, namely GTE1, will be considered as relevant for further stimulation.