The present invention provides methods/techniques and apparatus for displaying an angulation of a cassette and thus a patient at a time when an x-ray image is taken to provide for a better comparison of day to day improvement of the patient. More specifically, the present invention, allows a movable object to roll freely within in a passageway within an enclosure in relation to an angulation of a cassette. In order to correlate the position of the movable object in the enclosure with the angle at which the cassette is currently placed, a plurality of markers are disposed in or protruded from the inner surface of the passageway. Based upon the position of the movable object in relation to a particular marker at the time an x-ray is taken, the user can identify the angulation at which the cassette is currently positioned.

A surgical instrument. The surgical instrument has a force delivery system which communicates a changing force to a user of the surgical instrument when a limit of a surgical function is reached. A sensor senses position of a moving element to communicate a signal to the force delivery system. In various embodiments, the system generates a vibratory force to signal the user.