Abstract: A motion-sensing mechanism is provided that facilitates numerous aspects of the medical industry. In one aspect, the motion-sensing mechanism is used to track instruments and personnel in a field of view relative to a patient such that the instrument or personnel may be displayed on a heads-up display showing a model of the patient's anatomy. In another aspect, the motion-sensing mechanism makes a reference image of a patient, visitor, or staff such that when the subject of the reference images passes another (or the same) motion-sensing mechanism, the identity of the subject is determined or recognized. In still other aspects, the motion-sensing mechanism monitors motion of a portion of a patient's anatomy and compares the same to an expected motion for diagnostic evaluation of pain generators, physical therapy effectiveness, and the like.