Disclosed is a computer-implemented medical data processing method for determining a stimulated nerve fibre disposed in an anatomical body part of a patient's body, the method comprising executing, on at least one processor of at least one computer, steps of: a) acquiring, at the at least one processor, medical image data describing a digital image of the anatomical body part, wherein the anatomical body part contains at least one nerve fibre extending in a direction between an internal part of the anatomical body part and a substantially exterior part of the anatomical body part； b) acquiring, at the at least one processor, atlas data describing an image-based model of the anatomical body part including a representation of the at least one nerve fibre； c) determining, by the at least one processor and based on the medical image data and the atlas data, exterior part data describing an association between the exterior part and the nerve fibre； d) acquiring, at the at least one processor, stimulation signal data describing a predetermined applied stimulation signal applied to, based on the exterior part data, the exterior part； e) acquiring, at the at least one processor, check signal data describing an emitted stimulation signal emitted by the nerve fibre； f) determining, by the at least one processor and based on the stimulation signal data and the check signal data, correspondence measure data describing a measure of correspondence between the applied stimulation signal and the emitted stimulation signal.
