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.