Abstract: The invention is an optical sensor for detecting a signal emitted by a light source, for use in a placement detection system, the optical sensor comprising a line-sensor having a detection line comprising a pixel line (20) consisting of pixels (21), and an optical imaging means (17) imaging the light of the light source onto a light strip being cross-directional to the detection line of the line-sensor, the optical imaging means (17) being arranged with a distance from the line-sensor, the light strip having strip-boundary transitions on each of its two edges in the direction of the detection line. The inventive optical sensor is characterized in that the detection line comprises a pixel line (20), in which there are gaps between the adjacent pixels (21), and the optical sensor has a detection range ensuring that at least one of the strip-boundary transitions always falls at least in part onto a pixel (21).

Abstract: The system for performing ala operation in a virtual three dimensional space comprises a visualizing system for visualizing the virtual three dimensional space; a 3D position tracking system for marking, in the real three dimensional space, the real space position of the operation to be performed in the virtual three dimensional space; and a means for mapping the position of the real three dimensional space into the virtual three dimensional space and performing the operation in the mapped position. The 3D position tracking system comprises a positioning means provided with at least one signal source; at least two image sensors for detecting the signals emitted by the at least one signal source of the positioning means; and a first means for determining the real space position of the positioning means relative to the image sensors, based oil the signals generated by the image sensors and the spatial location of the image sensors relative to each other.

Abstract: The system for performing ala operation in a virtual three dimensional space comprises a visualizing system for visualizing the virtual three dimensional space; a 3D position tracking system for marking, in the real three dimensional space, the real space position of the operation to be performed in the virtual three dimensional space; and a means for mapping the position of the real three dimensional space into the virtual three dimensional space and performing the operation in the mapped position. The 3D position tracking system comprises a positioning means provided with at least one signal source; at least two image sensors for detecting the signals emitted by the at least one signal source of the positioning means; and a first means for determining the real space position of the positioning means relative to the image sensors, based oil the signals generated by the image sensors and the spatial location of the image sensors relative to each other.