| 摘要 |
A device for determining the longitudinal and angular position of a rotationally symmetrical apparatus (3) when guided inside a longitudinal element surrounding the same, including an imaging optical navigation sensor that measures the motion of the underlying surface by comparing successive images, and translates this image translation into a measurement of the longitudinal and rotational motion of the instrument. Features of the captured image are used to identify the insertion or withdrawal of the instrument, and to identify specific areas of the moving surface passing underneath the sensor, therefore allowing to establish the absolute position of the instrument, or to identify which instrument was inserted or in what cavity a tracking instrument was inserted. The device comprises a light source (31) and a light detector (32). Light emitted by said light source (31) is directed onto a surface (13) of the rotationally symmetrical apparatus (3). Reflected light from said surface (13) is detected by said light detector (32) to produce a position signal showing a locally varying distribution in the longitudinal direction (21) and in the peripheral direction (22) to enable said precise position and angular measurement. <IMAGE> |
