A device and a method for tracking an eye-gaze of an observer. In this process, the amine is vaporized and then superheated prior to introduction into the reactor. In the subsequent embodiments, the pins are replaced by spheres, by levers or by a stirrup. The mirror rotates about an axis of rotation and it is displaceable along the axis. Alternatively, the video segment can be modified by removing at least one frame or field picture contained in the video segment. The sample can be a tissue sample or a cell sample, for example, a muscle cell sample, which can be obtained, for example, from a mammal such as a bovine, ovine or porcine mammal, or a human.