A pedicle screw with a closure device including a seat element and a closure cap for quick closure of the seat element of the pedicle screw. Writing is disabled in response to determining that the current position error signal sample exceeds the stopwrite threshold. The method next includes the step of designating portions of the trial information for later use, followed by receiving confirmation of acceptance of the designated portions. An NRD waveguide is disclosed that includes an upper conductive plate and a lower conductive plate, with a dielectric channel disposed between the conductive plates. Further, in the image data correction, after the image data are converted to data having a smaller number of gradation levels, the data are delayed according to the serial arrangement of the print units.