Radiological Examination Apparatus

Abstract

A support for a patient, such as a chair, table or the like, is movably mounted on a track to slide horizontally, or move up and down, the track itself being rotatable within a ring-like frame forming a common structural support for the patient supporting device, as well as for an X-ray examining system including an X-ray source and an X-ray receiver, so as to position the patient to have the region of the patient's body to be examined at the center of the ring-shaped structure. The X-ray examining device itself is mounted on a two-axis gimbal, having its center of rotation coincident with the center of the ring-shaped structure, so that the same region of the patient's body can be examined from all angular positions in three dimensions, that is, can be spherically examined.

Description

The present invention relates to radiological examination apparatus, and more particularly to structural arrangements to support the patient with respect to an X-ray source and an X-ray image receiver in such a way that a region of the patient's body can be examined from all angular positions in space, and regardless of the position of the patient himself.

In certain radiological examinations, and particularly in X-ray examination of the head, it is necessary to locate an X-ray examining assembly formed of an X-ray source, and an X-ray receiver (such as a screen, a radiographic film, an X-ray image intensifier, an X-ray image television receiving tube or the like) in various positions with respect to the patient's head, in such a manner that the X-ray examining assembly can be located around the patient's head in three dimensions. In some of these examinations it is desirable that the patient be permitted to move, for reasons of comfort or, for example, to study the level and position of liquids or gases previously injected. Such medical examining techniques have already been done with apparatus in which the assembly of an X-ray generating tube and an X-ray image receiver is arranged to describe a spherical path (or a portion thereof) in space. The center of the sphere can be moved with respect to a fixed vertical axis. Apparatus to carry out such X-ray examination includes carrying arms carrying orientational axes forming right angles between themselves and the direction of radiation; in another system, a source-image receiver is movable about an axis which is swingable following an arc of a circle. The patient himself is supported on a table, or similar support, permitting complete rotation in his sagittal plane. It has been the practice to provide patient supports secured to the floor of the examining room, independent of the mountings and holders of the radiological apparatus, the patient supports being arranged to permit rotation of the patient about one, or two axes.

It has been found difficult in such installations to maintain the center of radiation constant with respect to the sections desired to be radiated, with out substantial manipulation of equipment or the patient on his support. Thus, it proved difficult to maintain the virtual center of the sphere described by the various positions of the X-ray source constant. It easily happened that the center of rotation was subjected to a substantially vertical displacement, so that the center itself, upon movement of the X-ray source in its given path would describe a circular path. Such movement of the center of the sphere defined by various possible paths of the X-ray system was superimposed on movement of the patient's head itself. the maximum off-center position which is a function of the diameter of the error circle described by the movement of the patient, was difficult to be compensated except by moving the support of the patient by a similar, compensating amount. To obtain accurate and clearly defined X-ray images, therefore, required complicated and careful manipulation, and it is almost impossible to design appropriate power-operated displacement arrangements which may be remote-controlled, because of The variety of possible positions.

It is an object of the present invention to provide a radiological examining apparatus, which can easily be operated by remote control and in which the center of examined part, of the parient's body, with respect to all possible axes of radiation, remains constant.

The invention will be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic front view of the apparatus in which the movable elements are placed in a position facilitating explanation of the invention; and

FIG. 2 is a side view of the apparatus of FIG. 1, partly in section, through an axial plane.

A fixed support B is provided to permit movement of the entire radiological apparatus in positions along the circumference of a sphere. Basically, an X-ray examining device is provided including an X-ray source 2 and an X-ray image pickup 3. The image pickup 3 may take many forms, for example an X-ray image intensifier connected to a television receiver, a radiographic plate, or the like. The X-ray examining assembly formed of source 2 and receiver or picture generator 3 is interconnected by a carrying arm 1, rotatable about an axis provided by shaft 4 4. Shaft 4, itself, is mounted in a gimbal 5 rotating, in turn, about axis provided by shafts 6 and located in the plane defined by the axis R-R.sub.1 of the X-ray generator 2. Gimbal 5 is carried at its extremities by two coaxial shafts 6 respectively mounted on two arms 10 which, in turn, are mounted on a ring-shaped structural support 9. The intersection of the axes 4, and that of shafts 6, defines a center 0 of an examining sphere. In FIG. 1, the axis R-R.sub.1 which defines the path of radiation is congruent with the axis of shafts 6.

A patient support 7, which may be a chair, table, or the like, is provided to locate the patient P in sitting or lying-down position. The support itself is also mounted on the ring-shaped support 9 by mounting means allowing its displacement along two axes which are at right angles to each other, as indicated by arrows f.sub.1, f.sub.2 and f.sub.3, f.sub.4, in order to center the portion of the body of patient P which is to be radiologically examined to coincide with the center O of the sphere. In sitting position, as shown in FIG. 1, the patient support, together with the patient, is rotatable in a vertical axis 8, corresponding generally to the longitudinal axis of the patient, permitting rotation of the centered organ of the patient's body whose center is located at point O. The support 7 may be displaced in the plane of the axis 4 of rotation, and parallel thereto along a traverse 11 which is an integral part of ring-shaped support 9.. Traverse 11 is secured to the ring-shaped member 9, for example by means of a suitable bracket, mounted on the ring 9 at point 12 (FIG. 2). The entire unit of radiological apparatus and patient support is thus a single assembly, by interconnection by the ring-shaped member 9 of which one axis is perpendicular to the plane of the paper of FIG. 1 and passes through the center O of the sphere. The ring 9 itself can rotate in the support B in a vertical plane by means of a drive (which may be remote-controlled) and which is not shown and well known in the art, for example by a chain transmission a rack and pinion, or worm gear arrangement. Thus, the entire unit of radiological apparatus together with patient may be rotated in a vertical plane. The structure of the apparatus accurately interconnects the position for the patient, on its support, and the source of X-rays, as well as the X-ray receiver for all axes of incidence, that is for all paths of the X-ray beam; thus, a large number of possible X-ray examining positions can be covered, with little handling and permitting substantial versatility and speed in examination. The comfort of the patient is increased and ease of operation for the technician provided. By mean of automatic, or remote-controlled positioning, automatic sequences of pictures can readily be taken, programmed in accordance with a desired pattern, so that a sequence of X-ray images of the same region of the patient's body can be obtained, looked at from various angles and orientations.

Claims

I claim:

1. Radiological apparatus for examining a patient in any position in space comprising:

a fixed base;

a common structural support mounted on said base for rotation about a first horizontal axis;

a pair of coaxial shafts rotatably mounted on said support to both sides of said first axis for defining a second axis perpendicular to said first one;

a fork-shaped bracket having extremities respectively mounted on said shafts pair for rotation about said second axis;

a further shaft mounted on said bracket, at about the middle thereof, for defining a third axis perpendicular to said second axis; said first, second and third axes intersecting at one point of intersection;

an arm member mounted, at about its middle, on said further shaft for rotation about said third axis, said arm member having two extremities;

an X-ray source mounted on one extremity of said member for emitting an X-ray beam, the central ray thereof transversing said intersection point;

an X-ray receiver for supplying a visible picture mounted on the other extremity of said arm member in radiation receiving relation relatively to said X-ray source;

a carrying member integral with said common structural support and including a straight portion parallel to said second axis;

a mounting member mounted on said straight portion for displacement therealong; and

means for supporting said patient movably, mounted on said mounting member, on the one hand, for rotation about a further axis parallel to a line perpendicular to both said first and said second axes and, on the other hand, for displacement in directions perpendicular to said straight portion,

thereby allowing the locating of a predetermined organ within said patient's body at said intersection point and the displacement of said X-ray source about a sphere whose center is located at said intersection point for carrying out X-ray examinations under substantially all possible angles of incidence of said X-rays relatively to said point.