US1954321A - X-ray device and method of - Google Patents

Description

.Nt kw April 1o, 1934.

WITNESSES April l0, 1934.

X-RAY DEVICE AND METHOD OF TECHNIQUE J. KIEFFER Filed March' 13. 1929 2 Sheets-Sheet 2 ratemeu npr. au, va-n 1,501,01 l

UNITED STATES PATENT oFFlcE X-RAY DEVICE AND IVIETHOD F TECHNIQUE Jean Kieffer, Norwich, Conn.

Application March 13, 192.9, Serial No. 346,651

` 4 claims. (c1. 25o-34) This invention relates to X-ray devices and the interpretation of a set of stereoscopic films of methods of technique. a lateral view of the chest is very diilicult, and,

The prime object is to provide an apparatus for, unless the pathology is very marked, often imand method of effecting the virtual focusing of possible. Although large cavities, pneumotho- 5 X-rays. races, effusions, consolidations, or large calcified 60 A further object of the present invention is to masses are easily seen and localized by such provide means for controlling the movement of technique, the visualization of small changes such an X-ray tube with respect to a body. as those occurring in the hilum or the medias- With the present apparatus and method the tinum is a very difiicult matter. In head work inherent advantages of a lens system for light superimposition of shadows is also very trouble- 65 rays areaccomplished for X-rays through consome and the usual means used to minimize it trolled movement of the X-ray tube with respect often results in distortion, which further complito a body or with the X-ray tube with respect to a cates interpretation. body and plate. From a consideration of the present specifica- By the use of the present method for X-ray tion it will be seen that the advantageous featreatment it will be found that the X-ray effects tures of the invention may have multifold pracmay be accumulated at a given point in a body tical uses in the industries, as well as in the medi- With a marked lessening of the injurious cumulacal eld. lit will be understood that the inventive effects on the surface or in other parts of the tion is not confined to medical use, and that the body, f terminology herein used which implies medical 75 Another object of the present invention is to use is not intended to restrict in any way the approvide an X-ray apparatus including tube and plication of the invention to medicine. For exu plate supports, by theuse of which an X-ray pho#- ample, in the examination of parts composed oi? tograph accentuating a specific object in a field superimposed metal inserts or the like, the focusmay be obtained, ing elect herein provided for will nd considers@ A further object is to provide a new method of able usefulness.

X-ray photography technique by which improved The problem solved by the present invention radiographs may be secured. is to provide means for obtaining a clear view Notwithstanding the highly developed roentof deeply seated parts uncomplicated by an excess genological techniques in use at the present time, of foreign shadows and without appreciable disthere are occasions when even the best of modern tortion. methods do not seem to be conducive to results Various other objects and features of the preswhich will give the diagnostician all theinformaent invention and the general advantages of the tion required. This is especially exemplified by apparatus and method set forth will be apparent the frequency with which the term superimposed from a consideration of the following specificashadows is heard when radiologists discuss the tion, taken in connection with the accompanying interpretation of X-ray films. drawings, in which- With the advent of the stereoscopic technique, Figure 1 is an elevational view partly in secthis superimposition of shadows has been elimition, showing the apparatus of the present innated to a large extent and the diagnostic value vention in side View; 95 of radiographs greatly increased. However, when Figure 2 is an end elevation of that form of bodily parts comprising a multitude of overlying the apparatus shown in Figure 1; shadow-producing components are radiographed, Figure 3 is a diagrammatic illustration showonly the best of stereoscopic techniques combined ing the principles of operation of the present apwith an eye and mind well trained in the interparatus and technique; '100 pretation of such films will yield results of real Figure 4 is a diagrammatic illustration more diagnostic value, and even these will at times not clearly disclosing the principles ofthe present approve suiiiciently adequate. paratus and technique.

A radiographic technique which would further Referring more particularly to Figures 1 and 2 diminish the difficulties of interpretation due to of the drawings, one embodiment of the appara- 105 the superimposition of shadows should therefore tus forming part of the present invention and prove of real value, especially in some phases of adapted for carrying out the technique of the chest or head radiography where superimposition present invention is illustrated. A

of shadows is usually very troublesome and often From the illustration of the apparatus it will leads to erroneous interpretations. For example, be understood that the structure is preferably ar- 119 ranged in conjunction with a conventional X-ray table, the side rail of which is indicated at 10 in the drawings, and preferably longitudinally adjustable upon the rail 10 a vertical standard 11 is provided. In the drawings the standard 11 and .that the specific construction of these and other parts of the invention as herein illustrated may be departed from without departing from the spirit of the invention. It will be further understood that the structure herein illustrated issubstantially diagrammatic in its illustration, and that in the commercial manufacture of therapparatus of the invention the full use of equivalents may be resorted to.

Associated with the standard 11 and vertically slidable thereon for adjustable positioning, a sleeve 12 is provided which is preferably of split construction, the ends being' joined through an adjusting nut 13, whereby the vertical position of the sleeve upon the standard 11 may be secured against accidental displacement. The sleeve 12 includes an inwardly extending arm 14 which terminates in an angularly disposed end 15, which lies parallel with the rail 10 of the table, and to which a U-shaped bracket 16 is pivotally mounted. The ends of the bracket 16 are adapted to engage an adjustable sleeve 17 which, similar to the structure of the sleeve 12, -is provided with an adjusting screw 18. `Through the sleeve 17 a vertical shaft 19 may slide for adjustment and is adjustably secured thereto by means of the screw 18. It will be understood that the adjustable pivoting of the shaft 19 may assume any desired structural arrangement in which means are provided for pivotally mounting the shaft 19 for vertical adjustment of its pivotal point with respect to the rail 10.

The lower end of the shaft 19 can slide through sleeve 20 pivotally mountedupon a connecting member 20 secured on a movable X-ray plate support 21. The support 21 is transversely movable upon rollers 22, which in `turn are supported by a carriage 23 longitudinally movable upon tracks 24 xedly secured with the rail l0. It will be seen that carriage 23 is provided with suitable rollers 25 which engage the tracks 24, and that 'the'wheels 22 roll upon tracks 26 mounted upon the carriage 23. It will be understood that this carriage may be adapted to have incorporated with it a Bucky diaphragm and actuating mechanism or its equivalent.

Inconsidering the plate support 21, it will be seen that the associated structure is such that transverse or lateral movement of the support of any combinations of such movements may be had by the support in response to movement of the shaft 19. It will further be seen that owing to the sliding pivotal arrangement at 20, which preferably includes a U-shaped bracket or gimbaling arrangement, as shown at 16, the support 21 retains a xed planefor its movement, which plane is at all times parallel with the plane in- 29 is supported upon al rigid supporting structhat pivotal movement of the shaft 19 will effect y corresponding transverse or longitudinal movenent of the tube support of the shield 35 and the For movement Voi the shaft 19 about its pivot point, a suitable motor 36 may be provided, which by means of a gear 37 rotates a disk 38 upon which a shaft 39 is eccentrically mounted, and which has its other end rigidly secured by means of an adjustable member 39 to the tube support 29. It will be clearly understood that rotation by the motor 36v may thus be imparted to the wheel or disk 38, and by suitable positioning of the eccentric point the shaft 39 may be arranged to suitably move the shaft 19 about its pivot.

It will be understood that the specific motive power for the shaft 19 herein illustrated may be departed from, and that the illustration of the mechanism herein disclosed provides only for one general type of motion. It will be understood that the shaft 19 may be manually moved about its pivot and that suitable mechanism may be associated in place of the motor 36 and wheel 38 for imparting any predetermined type of motion to the upper end of the shaft 19. It will be understood that this mechanism may be positioned at any place upon rigid supporting structure 30 or in conjunction with the support 11.

From the foregoing consideration of the apparatus herein presented it will be seen that a plate positioned on the support 21 will record in the usual manner of X-ray photography.I It will further be seen that when the tube 34 is energized and a plate carried by the support .21, the distance between the tube and the plate will not be varied through movement of the tube in response to movement of the shaft 19. It will be further seen that the focusing of the tube and plate with respect to all points in a plane parallel to the plane of motion of the -tube and plate, including the given point at which the shaft 19 is pivoted, will not be varied in response to movements of the shaft 19, but that all points between the tube and plate not lying within the plane at which the shaft 19 is pivoted will change'their focus with respect to the tube and plate as the tube and plate are co-ordinately moved by movement of the shaft 19. As will be hereinafter disclosed, this feature of the apparatus provides a structure admirably adapted to carry out the novel technique which forms part of this invention and which is hereinafter disclosed in conjunction with Figures 3 and 4 of the drawings.

Principle of system ing distracting outlines. In fact, it can be shown mathematically that this method achieves a result essentially similar to the focusing of the v,raya radiated from the target of an X-ray tube after they have traversed a partially transparent body. Due to the well-known fact that X-rays are not refracted or reflected by ordinary lenses or mirrors, this focusing of X-rays seems at first impossible; however, the mechanical system to be described accomplishes an effect similar to this focusing and follows thelaws of lenses andconcave mirrors. This is accomplished by giving a motion to the tube and to vthe film or plate. This motion is controlled by a linkage between the tube and plate, working in such a way that the film moves at all times in a direction reciprocal to that of the target and that the extent of their motion is proportional to the relative distance of target and film to the plane which is to be clearly seen.

This link, for the sake of clearness, can be represented as a straight rod T--O-P (Fig. 3)` pivoted at O, and capable of turning around points T and P, not only to right or left, but also forward and backward, (This isaccomplishedbya pivot system similar to gimbals.) At O is another pivot which can slide along rod TP and which can be set at any point, the height of this setting determining the height of the plane which will be in focus. Once set O is immovable in relation with the part to be radiographed; it becomes the center of the linkage system controlling the motions of tube and film, the motion of which is controlled in such a way that they can move only in planes parallel to one another and to the plane ofthe film.

It can readily be seen from this diagram that when T moves-to the right, P moves to the left, and that the amplitude of their motions is proportional to the distances TO and OP. It can also readily be seen that were point T at the exact center of the target,` and point O at the center of a point on the plane which it is desired to render sharply, the shadow of this point would fall at P and follow P for any movement described by T. Therefore, there would be no relative motion of the shadow of the point at O upon a lm placed at P and moving with it. But it is not essential that T, O and P be so situated. It will be seen later that as long as T is on a plane which includes the center of the target, and P on a plane which includes the entire surface of the film,` and as long as the target and the film move in planes parallel to one another and parallel to the surface of the film, this relation will hold for any point situated on a plane in which O is situated and parallel also to the lm surface. Therefore all points on a plane at AO will throw a shadow which will have no relative motion in regard to the lm and will be sharply rendered. It will also be shown that the shadows of all points situated any other plane will have a motion relative to the film and will appear blurred, this consequent blurring being greater as they are further removed from plane O, this degress of blurring being also dependent on the amplitude of the target travel and being increased when this travel is increased. v

But so far we have only taken into consideration' hold and the blurring will be circular. Any target motion can be used, provided that this motion is at all times parallel to the film surface.

We then have a system which will greatly diminish or completely remove the obstacle that superimposition of shadows present to the interpretation of certain X-ray films.

M athematicalconsiderations b respectively when target is at T, and at a' and b when target is at T'. The distance d between a and a' and d between b and b will be proportional to the distance t that the target has moved and to the' distance from the target to the plane AB and from plane AB to plane PP. So that if a film placed on plane PP is moved with point a, the shadow of point A will be stationary on the film. As the distance b to b' is equal to the distance a to a', shadow of point B will also be stationary, and similarly the shadows of all points on plane AB will be stationary on the film. And it is evident from the diagram that a system of linkage such as that described previously will move the film in a way exactly equal to the motion of the shadow of point A.

For a point Bz, outside of plane AB, the ratio of the distance between theiplane T'I" and Bz and the plane PP' is no t the same as for point on plane AB and the displacement of the shadow of point Be on plane PP' will be of a different value than shadow of point A and therefore it will not always fall on the same place on a film moving with the shadow of point A.

By putting the foregoing explanation in algebraic form they, and other peculiarities of the system may be better explained.

Referring to Fig. 4, we find:

Travel of target :t Travel of shadow of point A=d Distance of target to filrn=C Distance of point to film-:.Y

Therefore distance of A to T=CY and Yt CY will hold for any value of t and for any point on plane AB.

This is readily proved: Referring to Fig. 4Q

line T to a is perpendicular to plate TT' and PP and equal to C, we nd:

t" i(C-Y) tang. 1', c'l-r (Y) tang. 1" and as In! "d"- een Y Yt and d-C'TY At any other point on plane. AB, for example for point B, we nnd:

andas center on plane AB, the relation will always be v can be used to express any displacement of a to a for any displacement of T to T and that, as the film is always moving with a displacement equal to d the shadow of all points on plane AB will be stationary in relation to the lm no matter the speed of translation of T or its direction.

It is to be remarked here that though the distances between planes TT', AB and PP are always constant the distances between points T,

. O and P vary, necessitating sliding of link rod at points T and P, to compensate for these changes of length, or at points T and O ii.r the rod be fixed at P or at points O and P if the rod be xed at T.

The displacement de of the shadow points on any other plane than AB will not be equal to d. Taking for example, point Bz nearer to T than is plane AB, and expressing its distance to PP' as Yz, we have but Yz Y, therefore Yzt Yt c :c/ and dz d and for any point Bz', between AB and PP we have:

Yzt

C- Yz But Yz Y and dz d Ifv point Bz is on plane TT we get:

And when point Bz' is on plane PP':

Ot C We therefore nd that the shadows of all points not on plane AB will have a displacement greater or smaller than d, and as the displacement of the nlm is equal to d, they will all have a displacement relative to the lm, this displacement being relatively greater for points above than for points below AB and that this displacement tends toward innity (or d+ 1) as the points approach the-target plane and tends to approach the value of d (or d-O) as the points approach the film plane. And as this displacement causes blurring of the shadows of these points on the film, only points on lthe plane for which the pivot O is set (plane AB, or object plane) will have a sharp outline, all other points being blurred, this blurring being greater as the points are further removed from the object plane and relatively greater for points between this plane and the target travel plane than for points between the object plane' and the surface of the film. This blurring we also nd to increase directly as the amplitude of the target travel.

To sum up all this, we can say: that with the system of linkage used between the tube and the nlm, when the target is moved during exposure in any direction whatever along a plane parallel with the film surface it will impart to the lm a motion inverse and proportional to its travel; that the result of this will be tha-t all objects situated on a plane including the point of pivotage of the system will have a clear outline on the fihn, all other objects being more or less blurred; that the amount of this blurring depends on the distance of these objects to the plane in clear focus and on the amplitude of the target travel; and that the quality of this blurring depends on the path followed by the target.

From the above it will readily be seen that the technique of the present invention includes the linking of the X-ray target to the lm by a pivoted arm, the axis of pivotage of which -is in a plane parallel to the film and containing the object to be photographed. The target and plate are thus moved simultaneously and diametrically opposite but the planes in which they move retain their predetermined distance with yrespect to the particular portion of the object which is to be more clearly represented on the film.

Similar results could also be obtained with a similar linkage system by moving the target and object, the ,plate remaining stationary; or the plate and object, the target remaining stationary. The machine designed could be easily modied to do this, should it be advantageous to do so in certain cases. The principles involved are the same and the formulae for these systems similar to those for the system above described.

It is to be understood that the appended claims are not limited to the use of X-rays alone, but that when the term X-rays is used it is to be construed as meaning any radiation capable of penetrating and passing through aA substance, being therein absorbed in different degrees and capable of formirg an image either latent, virtual or real, either directly or indirectly, upon a suitable sensitive base. When the term lm or the term plate is used, it is to be construed as meaning such a suitable sensitive base with its attendant accessories (such as fluorescent or intensifying screen, or the like with their support) necessary for the direct or indirect recording of a latent, virtual or real image upon such a sensitive base; or the direct or indirect visualization of such a real or virtual image with the aid of suitable materials.

What is claimed is:

1. A photographic apparatus comprising a rigid support, an X-ray tube carriage movable on said support, lan X-ray tube holder movable on said carriage, a motor mounted on said support, 150

a plate carriage, a plate holder movable on said plate carriage, a vertical shaft having its upper end connected to said tube holder'and its lower end connected to'said plate holder, pivot means.

intermediate the ends of said shaft and means connecting said shaft with said motor to actuate said shaft about its pivot and simultaneously move said holders and carriages through independent paths.

2. A photographic apparatus comprising an upper track and a lower track, a carriage movable on said upper track, an X-ray tube holder movable on said carriage, a carriage movable on said lower track, a plate holder movable on said carriage, means for causing a movement of said carriages in one direction, said means operating to move said holders in another direction.

3. A photographic apparatus comprising an upper track and a lower track, a carriage movable on said upper track, an X-ray tube holder movable on said carriage, a carriage movable on said lower track, a plate holder movable on said carriage, a vertical shaft having its upper end pivotally connected with said tube holder and its lower end pivotally connected with said plate holder and means for actuating' said shaft to cause a movement of said holders.

4. A photographic apparatus comprising an upper track and a lower track, a carriage movable on said upper track, an X-ray tube holder movable on said carriage, a carriage movable on said lower track, a plate holder movable on said carriage, a vertical shaft having its upper end pivotally connected with said tube holder and its lower end pivotally connected with said plate holder` and means for actuating said shaft to cause a movement of said holders, said shaft operating to cause said carriages to move relative to said holders.

JEAN KIEFFER.

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