A method for detecting a position and an operating state of an active surgical instrument. The active surgical instrument emits or influences/modifies at least one electromagnetic field in an active operating state. The method includes the steps of positioning a first sensor in order to detect the electromagnetic field emitted or influenced by the active surgical instrument in the active operating state at a known position, detecting the electromagnetic field emitted or influenced by the active surgical instrument in the active operating state by means of the first sensor, generating an output signal by means of the first sensor, the output signal indicating the detection of the electromagnetic field emitted or influenced by the active surgical instrument by means of the first sensor, and ascertaining the position and operating state of the active surgical instrument on the basis of the output signal and the known position of the first sensor.
