Abstract: A positioning device produces controlled dynamic or kinematic movement in the cervical spine of a human patient either in the flexion or extension mode while the C-spine is being examined in a magnetic resonance imaging (MRI) apparatus. For dynamic movement the head is pivotally mounted in a headrest. For kinematic movement the various images which are taken in each incremental position are combined so that a cinematic video tape is produced. No movement of the head of the patient is forced but rather by the use of a ratchet wheel, a pair of pawls, overtravel cam, and suitable external operator activating controls, the patient may freely flex his head and then lower it to the next up or flex position or alternatively, freely lower his head to the next extension or down position.

Abstract: A positioning device for producing movement in the shoulder of a human patient in MRI apparatus includes a base movable into the aperture of the MRI apparatus. On the base is provided a swivel which includes a first lever pivoted on an axis, on which the shoulder is located, in substantially the plane of the base. And then with the elbow in an elbow cup located at the end of the first lever arm, a second lever arm is pivoted at the cup. The second lever arm at its distal end restrains the forearm or hand of the patient. Movement of this second lever arm is sensed by an angle encoder mounted on the axis of the elbow cup to indicate internal/external rotation. Movement of the first lever arm is sensed by an angle encoder at the first axis to provide abduction/adduction angle movement information. Flexion/extension movement is also provided.

Abstract: A kinematic device for producing precise incremental movement in the knee of a human patient for the purposes of producing a cinematic type display of MRI images with the knee at different angles of articulation includes a platform on which the patient lies on his side within the imaging volume of an RI apparatus. The one leg/knee being examined is restrained on a sagittal plane parallel to the horizontal platform and the other leg is elevated to allow movement of the calf of the leg being examined to move thereunder for full articulation. Examination of the other knee is provided by allowing for reversibility of a leg rest and other essential components. Also a remote drive is provided for the angle of articulation as well as a digital readout of such articulation.

Abstract: An automated angle encoder system for magnetic resonance (MRI) apparatus includes a removable encoder device placed on the orthopedic positioning device which is made entirely of nonmagnetic, nonmetallic materials and includes a glass disk which provides a GRAY output code to indicate absolute angle. The casing is made of Delrin plastic and the fiber optic cable includes nonmetallic TEFLON sheathing. Associated computer apparatus provides for an automatic input of an angle offset to provide for a neutral starting position and also for positive or negative angles of movement.