Abstract: A camera system for surgical navigation systems including a plurality of cameras mounted in a room. At least three cameras are mounted in the room which are operated in at least two different modes. In the first mode at least a subset of the cameras is operated to determine the position of markers and in a second mode at least a subset of the cameras is operated to determine the position of surfaces of the room.

Abstract: The present invention provides a method for modelling a position and orientation of a hand with as small a number of sensors as possible. A first sensor is attached on a phalanx distalis of a finger. The first sensor is adapted to provide information on at least five degrees of freedom that correspond to three translations, yaw and pitch. A second sensor is placed at a fixed position relative to a dorsum or palm of the hand. The second sensor is adapted to provide information on at least six degrees of freedom that correspond to three translations, yaw, pitch and roll with respect to a point of the dorsum or palm of the hand. A position and orientation of each of the first and second sensors is detected.