X-Ray Examination Apparatus

The invention relates to an x-ray examination apparatus comprising a column and a support-mounting which is adjustable in a vertical direction in relation to the column, and which holds a curved support at the one end of which a radiation source and at the other end of which an image layer carrier are mounted in alignment with one another. The support is rotatably mounted about a shaft, and a drive is provided for each of the translational and rotational movements.

U.S. Pat. No. 4,150,297 and British Pat. No. 2,098,440A, both incorporated herein by reference, disclose x-ray examination apparatus of this type wherein an x-ray tube and an x-ray image intensifier are mounted on oppositely disposed ends of a semicircularly curved support. The semicircularly curved support is displaceable on a support-mounting along a track at its circumference. In order that the semicircular support can be satisfactorily displaced in the support mounting, both must be manufactured with high precision. This is costly and makes the x-ray examination apparatus much more expensive.

An object of the invention is to produce an x-ray examination apparatus of the type initially cited which is simpler in construction and therefore cheaper than the conventional x-ray examination apparatus.

In accordance with the invention, this object is achieved in that the length of the support mounting, i.e. the distance of the front end of the support-mounting from the stand, is adjustable, and that the curved or bent support is pivotally mounted to an additional shaft, disposed horizontally or vertically depending upon orientation relative to the first shaft on the front end of the support mounting. Through these various parts of the x-ray examination apparatus it is no longer necessary to employ an expensive, semicircularly curved support. The support can now be designed in a bent shape in a U- or V-formation, which is far simpler in terms of manufacture and therefore makes the apparatus cheaper. In addition, no curved rail matched to the support is required.

In the case of an x-ray examination apparatus designed in accordance with the invention, it is proposed that the length of the support mounting be adjustable. It is therefore achieved that the stand need be mobile only in one plane. If the support mounting, in addition, is displaceable or pivotal relative to the stand, the necessary movement of the stand is reduced to one direction.

In view of a structurally simple adjustment of the length of the support-mounting it is advisable to design the latter in the form of a telescope. Alternatively, the support mounting can be designed in the form of a two-part articulated arm.

In an expedient embodiment of the invention, it is proposed that the support mounting be pivotally mounted on the stand in a vertical direction about a shaft. This makes it possible for the stand to be kept low.

In order that the support is pivotal in obstructed fashion over a large angular range, in a structurally advantageous embodiment of the invention, the support is laterally secured to the front end of the support mounting.

In an advantageous further development of the invention, it is provided that, for each adjustment movement, rotational movement, or pivot movement, a drive and a position sensor are provided. The signals of the position sensors are transmitted to a control device which, given a specified isocenter, in the case of a position change in one direction determines controlled variables for the other drives in such a fashion that, through their actuation, the isocenter is again adjusted. Through this technique, it is made possible that the support can be controlled in such a fashion that, independently of the course of movement of the x-ray tube, or of the image intensifier respectively, the isocenter can always be maintained.

FIG. 1 shows a lateral view of an x-ray examination apparatus in accordance with the invention;

FIG. 2 shows a schematic illustration of a control device for an x-ray examination apparatus in accordance with FIG. 1; and

FIGS. 3 through 5 show additional embodiments of an x-ray examination apparatus in accordance with the invention.

FIG. 1 shows an x-ray examination apparatus comprising a stand 1 which can be guided on floor rails 2 in a longitudinally displaceable fashion and parallel to a patient support table 3.

Vertically adjustably mounted on the stand 1 is a telescopic support mounting 4 for a U- or V-shaped curved or bent support 5. The support is pivotally mounted about a shaft or axle 6, and is secured perpendicularly to the longitudinal direction of the support mounting 4 at its front end via end part 50. The curved support 5 can also be directly secured to the shaft 6. The support 5 is preferably laterally secured on the front end of the support mounting 4. On the one terminating end of the support 5 an x-ray tube 7 is mounted, and on the other terminating end, an image layer carrier 8 is mounted. The x-ray tube 7 is centered with its central ray 9 aimed at the image layer carrier 8. The support is, in addition, rotatably mounted about a shaft or axle 11 which is attached to the end part 50 which is in turn connected by the shaft 6 to an extension of the supporting shaft 10 of the support mounting 4. The support mounting 4 is also designed in the form of a telescope, so that its length in a horizontal direction is adjustable.

In FIG. 2, it is illustrated that, for each adjustment movement, rotational movement, or pivot movement of the apparatus parts, a drive and a position sensor are provided. Thus, the stand 1 is controlled by a motor 12 and a position sensor 13. The height adjustment of the telescopic support mounting 4 proceeds by use of a motor 14 and a position sensor 15, and the length of the telescopic support mounting 4 is adjusted by a motor 16 and a position sensor 17. An additional motor 18 and the position sensor 19 control the pivot movement of the support 5 about the shaft 6. Finally, a motor 20 and a position sensor 21 for the rotation of the support 4 about the shaft 11 is provided.

Serving as control device 22 for the motors 12, 14, 16, 18, 20, and the position sensors 13, 15, 17, 19, 21, is a computer 23 and a control device 24. Connected to the control device 22 is a control console 25 whereby the position of the x-ray tube 7, or of the image layer carrier 8, are respectively controlled. Such a control device with control console is disclosed in U.S. Pat. No. 4,019,059, incorporated herein by reference, and will therefore not be described in greater detail.

If a position change of the x-ray tube 7, or of the image layer carrier 8 is to be conducted, selective motors 12, 14, 16, 18, and 20 are activated by the control console 25. The signals of the position sensors 13, 15, 17, 19, and 21 are supplied via connections 26-30 to the control installation 22. The control installation 22, then, given a specified isocenter 31, supplies via the connection lines 32-36, control variables to the remaining motors 12, 14, 16, 18, and 20 in such a fashion that, through their activation, the isocenter 31 is maintained. If the support 5 is now to be rotated through 90.degree. so that the x-ray tube 7 and the image layer carrier 8 assume the position illustrated in broken lines, the motor 18 is activated via the control console 25 in order that the support 5 is pivoted about the shaft 6. The control installation 22 then, in the described manner, controls the additional motors 14 and 16 such that the preadjusted isocenter 31 is maintained in the case of the position change of the x-ray tube or of the image layer carrier, respectively. The motors 14 and 16 cause the support-mounting 4 to be lowered and the telescopic arm to be moved outwardly. In a corresponding fashion, in the case of other desired movement paths, also the displacement of the stand 1 is controlled and the support 5 is rotated about the shaft 11. The isocenter 31 need not here be the geometric center between x-ray tube 7 and image intensifier or carrier 8, but can lie in varying positions, depending upon the adjusted enlargement. It is likewise possible, with the aid of the control, to shift the isocenter 31 in a randomly disposed object plane while the enlargement remains the same. With the aid of a memory not illustrated, it is further possible to retain the necessary data for a specific position of the apparatus and, after a random displacement, to automatically again adjust the initial position.

In FIG. 3, an additional embodiment of the x-ray examination apparatus of the invention is illustrated. In this sample embodiment, the support 5 is held by means of a two-part articulated arm 37. For the adjustment of the two parts relative to one another, a motor 38 is provided. The further end of the arm 37 is pivotal in the stand 1 about a shaft 39 by means of a motor 40. Associated with the motors 38, 40 are non-illustrated position sensors which are connected to the control installation (FIG. 2). Through the mounting and movement of the arm 37, the stand 1 can be kept low in this embodiment.

In FIG. 4, the telescopic support mounting 4 is pivotally mounted about a shaft 41 in the stand 1. As a drive and control, a motor 42 and a non-illustrated position sensor are employed, which are connected to the control installation shown in FIG. 2. The stand 1 can also be kept low in this embodiment through the support mounting 4.

FIG. 5 finally shows an x-ray examination apparatus comprising a stand 43 which runs both on floor rails as well as on ceiling rails 44, 45, and on which a stand carriage 46 is guided in a longitudinally displaceable fashion. The telescopic support mounting 4 is arranged in fixed fashion on the stand carriage 46.

The movement of the x-ray examination apparatus, which proceeds through the length-adjustable support mounting 4, or the articulated arm 37, can be replaced by a corresponding displacement of the stand 1, 43. This can proceed such that, in this direction, known and therefore non-illustrated rails are laid on the floor or on the ceiling. The stand 1, 43 drives on these rails. It is advantageously also possible to merely suspend the stand 1, 43 from the ceiling.

Through the x-ray examination apparatus of the invention, with the x-ray tube, or the image layer carrier, respectively, a spherical movement path can be conducted since the movements of the apparatus parts are mechanically decoupled and the various movement paths are synchronously controlled via a control installation. Through the movement paths of the apparatus parts, also the support can be manufactured in a simple and cheap form.

Although various minor changes and modifications might be proposed by those skilled in the art, it will be understood that I wish to include within the claims of the patent warranted hereon all such changes and modifications as reasonably come within my contribution to the art.