GB690656A - Improvements in or relating to x-ray apparatus for deep therapy - Google Patents

Abstract

690,656. X-ray apparatus. PHILIPS ELECTRICAL INDUSTRIES, Ltd. April 5, 1951 [April 8, 1950], No. 7932/51. Class 98 (i). [Also in Group VI] A deep therapy X-ray apparatus comprises an X-ray tube which, when in use, is continuously moved in combined linear and circular paths, the beam being always directed to a given area on the axis of revolution; and the X-ray tube is supported in its movements by an arm which in turn is eccentrically supported by a vertical rotatable disc, the tube and its supporting arm being linearly movable parallel to the axis of the rotatable disc. Alternatively the tube is moved in combined arcuate and circular paths, the arcuate movement of the tube including a component which is parallel to the disc axis. As shown, a disc 11 is supported to rotate vertically on rollers 12 mounted around an aperture 45 in a vertical panel 13 fixed to a base 14. A bar 9 slides in a sleeve 10 mounted in disc 11, and carries a housing 7 for an X-ray tube. The weight of this apparatus is balanced by a counter-weight 46. A drum 25 is mounted in a central aperture of disc 11, and an electric motor 36 is mounted on a bracket 37 on the bottom 26 of the drum. This motor drives through reduction gearing and a pinion 39, a toothed sector on an arm 33, which is forked and pivoted on opposite sides of drum 25, and is connected by links 34 to bar 9, which is thereby moved, together with the X-ray tube, parallel to the axis 16 of drum 25. The tube 8 through which X-rays emerge is connected by a link 30 to the arm 33, so that the X-ray beam is always directed towards a point 15 on axis 16. The disc 11 with the apparatus mounted thereon is rotated by an electric motor 22 driving a belt 24 passing around drum 25. In order to prevent the cables carrying current to the X-ray tube from twisting, a stop is provided preventing the disc 11 from turning through a full revolution, and switches thereon reverse motor 22 when the disc completes its travel in either direction. Other automatic switches control motor 36 to move bar 9 to and fro. By combination of the rotation of the disc and the movement of bar 9, the X-ray tube is caused to move over a predetermined path lying in the surface of a cylinder, the axis of which coincides with the axis 16. The patient is supported on a table 19, the end of which may enter drum 25, and the table is adjusted until the point in the patient's body requiring irradiation coincides with the point 15 towards which X-rays are always directed. A telscopic rod 17, carried on housing 7 and indicating the direction of the rays, is used for this purpose. When the apparatus is set in motion, and the tube is energized, the cumulative effect of the radiation is at a maximum in the region to be treated, and at a minimum elsewhere in the patient's body. In a modification, the bar 9 is directly pivoted to two parallel sets of arms such as 33, so that the focus of the X-ray tube moves on the surface of a sphere.