US3549885A

US3549885A - Apparatus for x-raying on two mutually perpendicular axes with a pair of x-ray sources

Info

Publication number: US3549885A
Application number: US743181A
Authority: US
Inventors: Sven-Erik Lennart Andersson
Original assignee: Saab AB
Current assignee: Saab AB
Priority date: 1967-07-10
Filing date: 1968-07-08
Publication date: 1970-12-22
Anticipated expiration: 1987-12-22
Also published as: BE717775A; FR1572841A; GB1169475A; DE1764580A1; SE335192B

Description

g axis. A detectplifiier and a video camera) is n u g g units are swin [56] References Cited UNITED STATES PATENTS 2,818,510 12/1957 Verse........................... 3,432,657 3/1969 Slavin...... 3,440,422 4/1969 Ballet Primary Examiner-Archie R. Borchelt Assistant Examiner-A. L. Birch Attorney-Ira Milton Jones ABSTRACT: A pair of X-ray radiation units are mounted on a carrier ring, circumferentially spaced and for radiation on axes perpendicular to one another and the rin ing unit (comprising an image am mounted on the ring opposite each, radiation unit. The carrier ring is confined to rotation in a surrounding annular frame mounted on heightwise adjustable legs on steerable wheels. Electromagnetic locking means releasably hold the rin against rotation in the frame. The detectin ble to and from inoperative positions outside the zone embraced by the carrier ring.

Sven-Erik Lennart Andersson Joenkoeping, Sweden [21] Appl. No. 743,181

July 8, 1968 [45] Patented Dec. 22, 1970 SAAB Aktiebolag Linkoping, Sweden a corporation of Sweden July 10, 1967 Sweden No. 10.404/67 MUTUALLY PERPENDICULAR AXES WITH A PAIR OF X-RAY SOURCES 6 Claims, 6 Drawing Figs.

[52] US. 250/61.5, 250/65, 250/92 .G03b 41/16 250/50,53, 61.5,65, 91, 92, 95, 58

United States Patent [72] inventor [22] Filed [73] Assignee [32] Priority [54] APPARATUS FOR X-RAYINGON TWO [50] FieldofSearch................

m j iwwaw m PATENTED 052221910 sum 3 or 3 EfiEi-i-j-EEES APPARATUS FOR X-RAYTNG N TWO MUTUALILY PERPENDICULAR AXES WITH A PAIR OF X-RAY SOURCES This inventionpertains to apparatus for conducting X-ray examinations along two coordinate axes of X-ray radiation, and the invention relates more particularly to X-ray apparatus of the type comprising a pair of X-raytubes'or radiation units arranged to radiate on different axes that substantially intersect within an object to be examined, a pair of X-ray detecting units, one for each radiation unit and each adapted to generate video signals corresponding to images produced by X-rays from its tube after the same have traversed an object being examined, and television receiving means connected with the detecting units for reproducing said images at a location or locations remote from the object.

While useful for conducting other types of X-ray studies and examinations, the apparatus of this invention is particularly useful in connection with medical and surgical examinations and procedures, wherein X-ray views taken on two coordinate axes are required for determining the exact position of a bid den object. In orthopedic surgery,for example, it is often necessary to be able to ascertain the exact location of a nail, pin, bullet or the like within the bone of alimb by means of X- rays radiated along a pair of mutually perpendicular axes transverse to the limb, and to be able to view the X-ray images at a substantial distance from the limb itself so that persons who have need of the information can obtain it without ap-' proaching the sterile operating zone to contaminate it or to interfere with movements of the surgeon performing the operation.

Heretofore it has been customary to mount the several components of such X-ray apparatus on individual wheeled stands or dollies, which had to be moved into place and adjusted one by one each time a new examining setupwas to be arranged. These several dollies occupied excessive floor space, required a great deal of careful manipulation to bring them into correct relationship with one another, and occasioned especially undesireable inconvenience and delay when they had to be moved during the course of a surgical procedure to establish them in a new arrangement. In addition to diverting the attention of the operating team from the actual surgical procedure, such shifting and readjustment of the apparatus during the course of an operation had the further very undesireable effect of requiring a number of persons to be present and moving about in the surgical zone, thereby greatly increasing the chances for contamination.

With the foregoing considerations in mind, it is the general object of the present invention to provide means for establishing the radiation and detecting units of X-ray apparatus of the character described in a fixed to one another while permitting them to be very readily adjustable as an ensemble, so as to avoid the need for adjustment and readjustment of those units relative to one another with each new, setup, but whereby the zone around the object to be examined is left readily accessible and whereby repositioning and rearrangement of the examining setup can be accomplished very quickly and easily.

More particularly, it is an object of thisinvention to provide a single carriagelike structure or dolly upon which are mounted a pair'of X-ray radiation units and a pair of X-ray detecting units, with the radiation units arranged to radiate along mutually perpendicular axes and with the? detecting units properly aligned with their respective radiation units and at the proper distances from them, which structure nevertheless provides for very quick and convenient adjustment of the orientation of the axes of radiation and leaves the object to be examined very readily accessible for surgical and other procedures.

It is also an object of this invention to provide apparatus of thecharacter described which occupies substantially less floor space than prior apparatus of the same type and provides for very quick movement of the detecting units to an inoperative position out of the zone of work on the object to be examined and for very quick return of said units to their operative posi- LII tions within that zone without the need for making adjustments to bring them'back into the proper relationshipto their radiation units.

With these observations and objects in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings. This disclosure is intended merely to exemplify the invention. The invention is not limited to the particular structure disclosed, and changes can be made therein which lie within the scope of the appended claims without departing from the invention.

The drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a perspective view of apparatus embodying the principles of this invention, together with its associated equipment, set up and arranged for a medical or surgical X-ray examination of a patients leg;

FIG. 2 is a perspective view of the supporting means of this invention for X-ray radiation and detecting units, viewed from the side thereof opposite to that shown in FIG. 1;

FIG. 3 is a sectional view on a larger scale taken on the plane of the line 3-3 in FIG. 2;

FIG. 4 is a fragmentary view on an enlarged scale, partly in perspective and partly in section, taken in the zone of the releasable locking means;

FIG. 5 is a detail perspective view of one of the detecting units in its relation to the carrier ring and particularly showing the means by which said unit is mounted on the carrier ring; and

FIG. 6 is a view taken on the plane of the line 6-6 in FIG. 2.

Referring now to the accompanying drawings, FIG. 1 illus trates X-ray apparatus set up for examination of a leg of a medical or'surgical patient and incorporating the apparatus of this invention which is designated generally by 5.

The apparatus 5 comprises, in general, a dollylike stand or carrier that supports a pair of X-ray tubes or radiation units 6 and 7, arranged to radiate, on mutually perpendicular axes, and a pair of detecting units 8 and 9, one for each of the radiation units 6 and 7 respectively. Each of the detecting units comprises an image intensifier section 10 and a television scanner or camera section 11 for generating video signals that correspond to the image of the object being subjected to X-ray examination. The detecting units are of a known type and therefore are not illustrated in detail, They are connected, by means of cables 12, with a television receiver 13 that reproduces that the images which they detect, for viewing at a distance from the object being examined. A pair of foot treadle operated switches 14 provides for selection of the X-ray system image that is to appear on the receiver.

, The control system for the X-ray apparatus can comprise a conning bench 15, preferably mounted on wheels, in which is housed the high tension current supply for the radiation units and on which are located the necessary controls and monitoring instruments for the apparatus as well as a viewing screen connected with the detecting units. The apparatus of the conning bench is connected with the X-ray apparatus by means of cables 16.

The apparatus of this invention (best seen in its general arrangement in FIG. 2) comprises a rigid frame 17, preferably annular, which has its axis horizontal and which is supported on upright tubular legs 18 and 19 that are rigidly secured to the frame at opposite sides thereof. The frame 17 supports an inner carrier ring 20 which is rotatably mounted therein and on which are mounted the radiation units 6 and 7 and the detecting units 8 and SI.

The frame 17 and legs 18 and 19 are wheel mounted to provide a stable but readily maneuverable tricycle chassis. Specifically, one leg I8 has at its bottom an elongated horizontal foot 21 which is supported on a pair of steerable wheels 22, one under each of its end portions, while the other leg 19 is supported on a-single castered wheel 23. The foot 21 can be mounted on the leg 18 to swing about the axis of said leg and can be locked in various positions of such swinging motion by means of a clamping screw 29. The wheels 22 on the foot 21 are steerable in unison about upright axes by means of a handwheel 23 concentric with the leg 18. The connection between the handwheel and the wheels 22 can comprise a chain 24 trained around sprockets on shafts concentric with the handwheel and with the pivot members on which the wheels 22 are swivelably mounted. Suitable brake means, controllable by a foot pedal 26 and enclosed in small housings 27 on the end portions of the foot 21, can be provided to releasably lock the wheels 22 against both rotation and swiveling about their steering axes.

To provide for adjustment of the height of the frame, each of the legs 18 and 19 is made of telescoping members or is otherwise arranged to be adjustable in length by means of a crank 28 connected with a self braking jack screw or the like within the leg.

The carrier ring can be made in two axially

adjacent parts

31 and 32 which have coaxial interengageable circumferential shoulders, as at 33, to confine them to concentricity. The carrier ring parts are connected by circumferentially spaced bolts 34 that extend parallel to the carrier ring axis. On their adjacent peripheral edges the ring parts have substantially

large bevels

35 and 36, respectively; which cooperate, when the ring parts are assembled, to define a V-shaped radially outwardly opening circumferential groove that opposes a V- shaped inwardly opening circumferential groove 37 in the annular frame 17. Balls 38 are confined between the opposing surfaces of these grooves to provide bearings by which the carrier ring is confined to rotation in the frame. It will be observed that drawing the

carrier ring parts

31 and 32 axially toward one another, by means of the bolts 34, reduces the width of the V-shaped groove defined by the

bevels

35 and 36, so that play between the carrier ring and the frame can be eliminated.

Each of the

carrier ring parts

31 and 32 has a radially outwardly opening circumferential groove 39 which opens to an opposite radially inwardly opening groove .40 in the frame, and these two sets of grooves cooperate to define a pair of annular chambers 41 and 42 that are conjointly defined by the carrier ring and the frame. Sealing rings 43 confined between the frame and the carrier ring seal'the annular chambers 41, 42 to prevent the entry of dirt between the carrier ring and the frame.

Since the X-ray tubes and detecting units are mounted on the ring to partake of its rotation relative to the frame and its other movements as the frame is raised and lowered and moved about on its wheels, the radiation axes of the X-ray tubes will always be perpendicular to one another and to the ring axis, and the detecting units can always be in the proper coaxial and spaced relationship to their respective radiation units. Hence it is not necessary to make adjustments of these units whenever the radiation axes are reoriented. To facilitate rotational adjustment of the ring in the frame, the subassembly comprising the carrier ring and the radiation and detecting units is preferably statically balanced.

The carrier ring can be releasably locked in any desired position of rotational adjustment by braking means comprising a strip 44 of rubber or the like that extends all around the bottom of the groove 39 in the carrier ring that defines the chamber 42. Preferably this strip has regular transverse ribs 45. Secured to the frame, and housed within the annular chamber 42 at each of a pair of diametrically opposite locations is an electromagnetically actuated shoe 46 that is provided with transverse ribs which are matingly engageable with the ribs 45 on the strip 44. Normally the shoe is biased into engagement with the strip, as by means of springs 48 that react between the frame and the shoe, but upon energization of the electromagnet the shoe is drawn out of engagement with the strip to release the carrier ring for rotation. The electromagnets which actuate the shoes 46 can be energized under the control of a control box 47 on the frame, connected by suitable cables with the electromagnets and the conning bench 15.

Each of the detecting units 8 and 9 is secured to the carrier ring 20 by means of a hingelike connection, generally designated 49, by which it can be readily swung to an inoperative position in which it is outside the zone embraced by the carrier ring, to present the least possible interference a surgeon working in that zone, and to an operative position in which it is properly aligned with and spaced from its radiation unit. Each of the connections .49 (see FIGS. 5 and 6) comprises a generally L-shaped bracket 50 having one leg 51 that overlies the radially inner surface of the carrier ring and is secured thereto, and another leg 52 that overlies one axial face of the carrier ring and the annular frame 17 and projects radially outwardly beyond the latter. Swingably connected to the bracket by means of a pivot pin 53 is a flange 54 that flatwise overlies the leg 52 of the bracket 50 when the detecting unit is in its operative position. The pivot pin 53 is located radially outwardly of the annular frame and has its axis slightly to one axial side thereof and approximately tangent thereto.

On the outer face of the flange 54 there are fixed mounting lugs 56 through which slidably extend a pair of parallel rods 57 that have their opposite ends fixed to the detecting unit. The lugs and rods cooperate to confine the detecting unit to motion relative to the flange 54 in directions parallel to the viewing unit axis and to the faces of the flange. A threaded spindle 58, actuatable by means of a crank handle 64) and cooperating with an internally threaded lug 59 on the flange 54, is confined to rotation relative to the detecting unit to enable the detecting unit to be adjusted axially relative to its radiation unit. The crank handle 60 is axially slidable on the spindle so that when not in use it can be slid rearwardly to an out-of-the-way position in which its actuating knob is received in a recess 61 in the front of the detecting unit.

To hold the detecting unit in either of the positions to which it may be swung, a sector-shaped plate 62 is secured to the flange 54 to pass edgewise through a slot in the outer leg 52 of the bracket 50, and it has notches 63 in its curved edge in which can be engaged a latch 64 that is mounted on the face of the leg 52 that is remote from the flange 54.

It will be understood that the radiation units 6 and 7 can also be secured to the carrier ring by means of attachments similar to the hinge connections 49 described above, so that they too can be swung to operative and inoperative positions.

From the foregoing description taken with the accompanying drawings it will be apparent that this invention provides means for so supporting a pair of X-ray radiation units and.

their associated detecting units that the same can be maintained in a desired relationship to one another, with the radiation units radiating on substantially intersecting axes and the detecting units aligned with their respective radiation units and properly spaced from them, but whereby said units can be readily positioned and repositioned as an ensemble without the need for readjustment of individual units, and which apparatus can be readily adjusted to any desired orientation of the axes of radiation, occupies little floor space, and leaves accessible the zone around an object being subjected to X-ray examination.

lclaim:

1. Means for supporting a pair of X-ray radiation units and a pair of X-ray detecting units, 181 one for each radiation unit, with the axes of radiation of the radiation units substantially perpendicular to one another and with each detecting unit spaced from and opposite its radiation unit, said supporting means comprising:

A. a carrier ring large enough to encircle an object to be examined;

B. means mounting the radiation units at circumferentially spaced locations on the carrier ring and for radiation in directions substantially radially inwardly of the ring;

C. a carriage comprising an annular frame cooperable with the carrier ring to coaxially carry the same and which has its axis substantially horizontal;

D. cooperating means on said frame and on the carrier ring constraining the a carrier ring to rotation about its axis relative to the frame;

E. a pair of hinge elements for each detecting unit, one

secured to the detecting unit and one secured to the carrier ring substantially diametrically opposite the radiation unit for the detecting unit; and

F. pivot means connecting each pair of hinge elements for relative swinging motion about anaxis which is substantially tangential to the carrier ring but is spaced radially outwardly therefrom so that the detecting unit can be swung to an operative position pointing to its radiation unit and projecting radially into the zone encircled by the carrier ring, and to an inoperative position substantially aligned with the carrier ring axis and disposed outside said zone.

2. The apparatus of claim ll, further characterized by releasable locking means on the frame engageable with the carrier ring to confine the latter'in any desired position of its rotation.

3. Theapparatus of claim 1 further characterized by said means mounting each detecting unit on the carrier ring providing for adjusting movement of the detecting unit toward and from the axis of the carrier ring.

4. The apparatus of claim 1, further characterized by said carriage comprising:

A. a pair of heightwise adjustable legs secured to said frame at diametrically opposite sides thereof; and

B. swivelably mounted wheels on the bottoms of said legs by which the apparatus can be rolled about on a floor in different directions.

5. Means for supporting a pair. of X-ray radiation units with their axes of radiation substantially perpendicular to one another, and a pair of X-ray detecting units, one for each radiation unit and each having means for generating video signals corresponding to the X-ray image of an object between the radiation unit and the detecting unit, said supporting means comprising:

A. a carrier ring comprising l. a pair of axially adjacent ring parts having:

a. concentric interfitting circumferential shoulders by which the parts are maintained coaxial and b. beveled axially adjacent outer circumferential edges cooperating to define a radiallyoutwardly opening V-groove in the carrier ring, the width of which depends upon the axial spacing between the ring parts, and

2. means connecting the ring parts at circumferentially spaced intervals around them and providing for adjustment of the axial spacing between them;

B. an annular supporting frame concentrically embracing the carrier ring and having a radially inwardly opening V- groove which opposes said V-groove in the carrier ring;

C. a plurality of balls confined between the frame and the carrier ring, in said opposing V-grooves, to constrain the carrier ring to rotation in the frame;

D. means providing a steerable wheeled chassis on which the frame is rigidly supported with its axis substantially horizontal and providing for heightwise adjustment of the frame; and

E. means securing said units to the carrier ring at circumferentially spaced locations thereon, with the axes of the radiation units substantially perpendicular to one another and to the frame axis and with each detecting unit substantially diametrically opposite'its radiation unit.

6. Means for supporting a pair of X-ray radiation units with their axes of radiation substantially perpendicular to one another, and a pair of X-ray detecting units, one for each radiation unit and each having means for generating video signals corresponding to the image of an object between the radiation unit and the detecting unit, said supporting means providing for facile group-wise axis orienting adjustment of the units and comprising:

A. a carrier ring large enough to encircle an object to be examined; B. means mounting the radiation units at circumferenttally spaced locations on the carrier ring and for radiation in directions substantially radiallyinwardly of the carrier ring; C. a carriage comprising 1. an annular frame and 2. means mounting the'frame with its axis horizontal, said mounting means providing for heightwise adjustment of the frame and for horizontal movement thereof in all directions;

D. means coaxially mounting the carrier ring on said annular frame for free rotation of the carrier ring about its axis;

E. A strip of rubberlilte material that extends circumferentially around the carrierring and has a surface facing the frame that defines numerous circumferentially spaced ribs that project toward the frame; and

F. locking means for releasably holding the carrier ring in any desired position of its rotation, said locking means comprising I l. magnetically permeable plunger means carried by the frame and constrained to motion relative to the frame in directions toward and from engagement with said said ribbed surface;

2. yielding biasing means reacting between the frame and the plunger means to bias the latter in the direction toward said ribbed surface; and i 3. electromagnet means fixed on the frame and energizable to move the plunger means in the direction away from said ribbed surface.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,549 885 Dated December 22, 19 70 Inventor(s) Anderson, Sven-Erik Lennart It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1 Line 53 Insert relationship" after i'ix' Column 4 Line 60 Delete "181" after units Column 4 Line 74 Delete "a" after the Signed and sealed this 6th day of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. Attesting Officer WILLIAM E. SCHUYLER, JP Commissioner of Patent FORM PO-1050 00-69) USCOMM-DC e031!