Abstract: The invention concerns a lock device for use in connection with elongated surgical instruments such as surgical needles, electrodes, etc., wherein the lock device consists of at least a first and a second distance member which surround the surgical instrument and a third stop member. All the parts are movable in the longitudinal direction relative to the instrument and thereby relative to one another, they are individually lockable in the depth position relative to the instrument and are equipped with indication devices for indication of position relative to one another, with the result that the instrument's movement in the longitudinal direction (depth) is controlled by controlling the distance for the relative movement between the distance members.

Abstract: The invention concerns a device for adjusting stereotactically and endoscopically located equipment, including pharmaceutical agents, radiation sources and organic material, comprising a holder and a fixing key, where the holder comprises a lower ring (1) for receiving a ball (2) which will form a ball joint, and an upper ring (3) for locking the ball in a specific position, where the ball (2) has a channel for insertion of medical instruments, and where the lower ring (1) has an external threaded surface (8) for direct screwing to an area of a patient's skull. The device is characterized by the fact that the ball's (2) central point, and thereby the ball joint's fulcrum is arranged for positioning on a level with the patient's cranium by way of a groove-like or curved surface (21) on the holder which forms an abutment for the ball (2).