Abstract: Medical apparatus includes a patient table (7) with a table support (9) and a table top (11) which is movable at least in its longitudinal direction relative to the table support, there being provided a first drive mechanism (21) to assist said movement, if desired; the table top can be locked relative to the table support by means of a locking mechanism (23). The apparatus comprises a common control member (43) for moving the table top (11) in the longitudinal direction and for operating the first drive mechanism (21) and the locking mechanism (23). The control member comprises a link rod (57) which is movable in its longitudinal direction and which cooperates with a switch (67) for operating the locking mechanism, and also comprises a control element (71) which is movable transversely of the longitudinal direction of the link rod and which cooperates with a sensor (73) which supplies an output signal for control of the drive mechanism.

Abstract: Apparatus for plan-parallel tomography comprises an X-ray tube and detector which are mechanically connected to each other by means of an extendable column consisting of two portions. Linear movement of the X-ray tube is obtained by sliding the two portions during the swiveling of the column. The use of customary servo control arrangements for sliding in or out, however, involves a position error which is approximately proportional to the sliding speed of the column portions. This position error is eliminated by the adding of a correction signals which is proportional to the sliding speed into the servo control signal.