A digital interface systems for controlling a computing device and prosthesis technology for compensating the loss of a limb. In one example, a digital interface system for translating a myoelectrical signal into a control command for a computing device is provided. The system includes a myoelectrical sensor arrangement, which is configured for sensing at least one myoelectrical signal of a muscle and/or of a nerve of a muscle. Additionally, the system has a pointing device adapted for detecting a two-dimensional motion of its own wherein the pointing device has at least one optical location-sensor. Additionally, the sensed myoelectrical signal of the myoelectrical sensor arrangement and the pointing signal of the pointing device can be fed into a controlling means.