Patent GB-1098547-A (GB)
Title: Improvements in or relating to diagnostic x-ray units
Inventor: BRYER ROBERT FRANK
IPC: A61B6/04
Filed: 1965-10-15
Abstract: 1,098,547. X-ray apparatus; palpator mechanism. GENERAL ELECTRIC CO. Ltd. Nov. 28, 1966 [Oct. 15, 1965], No. 43909/65. Heading H5R. A diagnostic X-ray unit incorporates a palpator member mounted on a carriage which may be driven by reversible drive means so as to bring the palpator into contact with the patient, the member being displaced from its rest position against a biasing means by such contact; the unit also incorporating a control member having a rest position from which it can be displaced against biasing means, and electrical elements associated with the palpator and control members which elements have characteristics varying in accordance with the amount of displacement of the palpator or the control member from its rest position, said elements forming part of a control circuit for operating the drive means in one or other direction depending on the relative displacements of the palpator and control members such that the pressure exerted by the palpator on the patient is a function of the displacement of the control member. In Fig. 2, there is shown an X-ray unit comprising a couch 1, image intensifier 4 on annular rotatable support 27, with support 6 vertically adjustable on beam 29 and with pillars 5 supporting tube assembly 3 and also supporting slide 7 carrying arms 8 between which arm 10 carrying palpator 13 is pivoted on pivot 9. Arm 10 is maintained horizontal by the combined action of biasing spring 11 and stop 12. When drive means, e.g. a reversible electric motor (not shown), are activated by pressing lever 16 from its rest position against spring 18 which causes the electrical characteristics of transducer 15 to alter and generate an activating signal by unbalancing a bridge circuit formed by trans. ducers 14 and 15, the carriage 7 moves palpator 13 towards the patient until arm 10 operating against biasing spring 11 alter the characteristics of transducer 14 sufficiently to restore the balance of the bridge circuit. Transducers 14 and 15 are selected so that the pressure on lever 16 is approximately the same as that applied by palpator 13. Lever 16 may be retained by a ratchet device in a desired position and it is arranged that an upward pull on lever 16 displaces stop 23 on spring 24 and actuates microswitch 25 so as to reverse the motor and withdraw the palpator arm completely clear of the patient, the slide 7 progressing up the column until the motor is stopped by actuation of microswitch 26. As an alternative, lever 16 and arm 10 may be connected to circuit elements which generate a signal according to the amount of displacement, these signals being compared in an appropriate device which generates a signal for operating the motor according to the results of the comparison. Amplifiers may be incorporated in the circuit to provide adequate power from the generated signals. If the layout of the X-ray equipment is such that the X-ray tube is below the patient couch with a screen assembly or serial changer situated above the couch then the movable carriage of the palpator arrangement may be provided by the serial changer or the screen assembly.