A nerve mapping system includes an elongate medical device, a non-invasive mechanical sensor, and a processor. The elongate medical device includes a distal end portion configured to explore an intracorporeal treatment area of a subject, and the distal end portion includes an electrode. The non-invasive mechanical sensor is configured to provide a mechanomyography output signal corresponding to a monitored mechanical response of a muscle innervated by the nerve. The processor is in communication with the electrode and the sensor, and is configured to provide a plurality of electrical stimuli to the electrode. Each of the plurality of stimuli is provided when the electrode is located at a different position within the intracorporeal treatment area. The processor determines the likelihood of a nerve existing at a particular point using the magnitudes of each of the stimuli and the detected response of the muscle.