MODEL RELEASED. Nerve test. Woman undergoing a nerve conduction velocity test (NCV). This tests the speed at which impulses travel through a nerve. Surface electrodes have been attached to the patient's fingers (not seen) and a small electric shock is being applied to her arm by a doctor. The distance travelled and the time it takes for the electric shock to be relayed to the electrodes is used calculate the nerve conduction velocity. The monitor on the left shows a graphical record of the test's results. An abnormal NCV result indicates neuropathy (nerve damage).