US1704477A - Method of and apparatus for converging and diverging rays emitted from alpha source of radiant energy - Google Patents

Description

March 5, 1929. M. JACOBSON 1,704,477

METHOD OF AND APPARATUS FOR CONVERGING AND DIVERGING I RAYS EMITTED FROM A SOURCE OF RADIANT ENERGY Filed May 12, 1924 3 Sheets-Sheet 1 20 i q i 77 T J2 3/ l w. flmrmnnnnnnnnnllnnnrulnnnnnlmnnnnnnnnnnnl1nIInnnnnnnnnnnnnnnnnnnnnn- H H; .JIGI."

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March-=5, 1929. JACOBSQN 1,704,477

' METHOD OF AND APPARATUS FOR CONVERGING AND DIVERGING RAYs EMITTED FROM A SOURCE OF RADIANT ENERGY Filed May 12, 1924 3 Sheets-Sheet 2 anomtoz fling/mfg March 5, 1929. JACQBSQN 1,704,477

METHOD OF AND APPARATUS FOR CONVERGING AND DIVERGING RAYS EMITTED FROM A SOURCE OF RADIANT ENERGY Filed May 12,1924 s Sheets-Sheet 5 'Patentetl Mar. 5, i929.

MOSES JACOBSGN, OF BRONX,

new roan, Assmnon or ONE-HALF r0 LOUIS s.

ABONSON. i

LETHOD 0F Alli) APPARATUS FOR CONVERGING. AND DIVERGING RAYS EMITTED FROM A SOURCE OF RADIANT ENERGY.

Application filed'May 12,

X-rays, rays from radioactive substances and the like emitted from asource of radiant energy, as is well known, spread out in all directions from the source and do not show regular reflection or rettr ction and hitherto it has not been possible toproperly concentrate or disperse them; This, however, is frequently required in order, for instance, to enable the concentration of the rays to the exact spot within the body of the patient to be {treated and thereby avoid injury to other parts not requiring treatment, or for obtain-- ing enlarged or diminished photographic or :fiuoroscopic pictures ot the internal parts the human body, machinesor the like, or for naking enlarged pictures or microscopically small opaque subjects.

The object of my invention is to provide a con'iparatively simple method of and means for converging or diverging such rays tor the purposes mentioned or other purposes, where the same may be required.

While in the following I will describe and illustrate my new method and apparatus as applied t X or Roentgen rays, I wish it to be expressly understood that my inventionis net as well applicable to rays from radioactive substances and also to visible, ultraviolet and infrared rays and to electro-magnctic and acoustic wavesin all cases where the use oi lenses or mirrors is too expensive or results in too much absorption or is undesirable for any other reason. 7

It must also be expressly understood that the method and apparatus .hereinaiterdescribed and shown are only some 'embodiments oi my invention and that since various modifications may be made by those skilled in the art without departing from the prin-- ciple thereot. I do not wish to restrict myself to the details described and shown.

My nvention will be more fully understood in; reference to the accompanying drawing illustrating means for carrying out my method 2 ad in which 1 is a vertical section oi an Il-ray apparatus equipped with my new means i is a diagrannnatic view of the same apyuiratus changed to perform movements somewhat different from those oi Fig. 1, when it is desired to make the rays di- Fig. 2 is a cross section on line 22 1 i, Figs. 3, l, 5 and 6 are diagrams il 1g the principle on which my inven- V eased; g. 7 is merinlcatien at rest. lo obtain. a divergence-or 1924." serial No. 712,889.

matic views at right angles to one anotherot a modified X-ray tube, and Fig. 12 shows an arrangement for directing rays from'a plurality of sources upon a single point.

According to my invention, I separate from the rays,- for instance, X-rays, emitted from the-target of. one of the usual X-ray tubes, a narrow beam by meansof one or more diaphragms. diaphragms relative to the source of rays and of both dianhragms and source together relative to the body or object which is to be radiated through, the said narrow beam is caused to follow predetermined directions" on its path to and through the body. In or der to make the rays converge toward a desired focal point or diverge from a focal point. dii ferent from that of the natural source of emission, the source of raysand one or more diaphragms are moved in space relative to 7 one another and to the body and tothe pho togra'phlc film or fluoroscopic screen in such a way that the point of emission ofthe rays and the passage left open by all diaphragms remain always on a straight line swinging around a fixed point as a center, so that the beam ot rayspassing through is always directed toward or from said focal point. These movements are so controlled as to direct the beam of rays successively and continuously Changing the position of the through all parts of the body to be radiated.-

'lo radiate through bodies of big dimen sions, a plurality of equidistant and equal sources of rays may be used connected each with its own systemof moving diaphragms and movedsimultaneouslyin such away that allf beams of rays shall be directed towards one common tt'ocus.

All movements are designated as relative movements. T hat means that-instead of mov ,ing the source'ot rays and the diaphraglns a d. keeping the body and the recipient of the energy.(film, screen, etc.) at rest, exactly the same results may be obtained by moving say the oody and thediaphragms, and keeping the source of rays and the recipient at rest, or

by moving the source of raysa nd the body,

and kee the diaphragms and recipcnts V Y, 3 wer off the in s, at. least inc the said el ments must be moved, but there can be also combinations of movements of more than two of them giving the same relative motions.

lheprinciple of myinvention best illustrated in the diagrams, Figs. 3, l, and 6,is as follows Let T (Fig. 4) be the target of an X-ray tube, a. radioactive substance or generally a source of raoia-nt energy; a photographic plate, film, fluorescent or other rec'ip ient of energy or rays; a diagram of suitable materialthrough which the rayscould not pass except through its opening 26 (for 'X-rays or radium rays the material of the diaphragm may be lead) and finally let B denote the body to be treated or radio graphed it is obvious that it the tube T s moved from T to 'l" one the diaphragm Q5 moved at the same time to position 25, so that its opening 26 always remains with the target on straight line turning around the point F as on an axis, the narrow beam of rays will gradually cover the cntiretriangle T T Rand that this will be the same result as when the rays are made converge tovard F by a lense or a spherical mirror. lf

the diaphragn'i 25 is moved in the same direc- 7 frame or guide 14 on which is movablv tion asthe target T, the focus is below or behind the diaphragm, as in l, and the rays are thus made to converge. If thetarget "T and tie diaphragm 25 are moved in opposite directions according to Fig. 5, and the focus F is located between'the target T and the diaphragm, the raj-is are caused to diverge. The first named arran 'ement may be used ween it isv desired to effect'concentration; of the rays to a single spot of the body treated or to obtain reduced photographic or fluoroscopic pictures, while second arrangement will be used when it IS desired to cover a large area, as for instance to stimulate seeds byiC-ray treatment or to produce enlarged photographic X-ray piel'lu'cs. The divergence of rays by my method preferable to the natural divergence of the rays when emitted from the target, because by my method, 1 can adjust the focus to be much sharper than the natural focus and thus can producea much sharper enlarged picture, and also can bring the focus much nearer to the body and have a cone of rays wile a much wider angle. 7 It is obvious that to radiate through bodies having three dimensions, the described movemcntsof the passed beams of rays must be carried out not in one plane, hutin two l preferably at right angles to each other. ihis be uerou ish d, as will be hereinat'lc shown, b u. .ue wo sonar-ale diapln'ag'uic with slits moving at rignt angles to each other and in such a manner that after each stroke of one diaphragm and the source the other and the source are advanced a certai. distance. The X-rays will then describe a zig-Zag line, as shown diagrammatically in Fig. 3. Or the same result may be accomplished by having a diaphragm together with the source revolving in concentric circles around a-common axis and at the same time moving in radial direction, thereby d'esc- r1b 1, 1 and 2, I assume the X-ray or Been en tube T to be of the well known construction, comprisingthe usual. target from which rays are emitted in well known manner .l further assume that the a )paratus here shown is of the kind used for medical treatment or for taking X-ray pictures or the lilre. Such apparatus ordinarily comprises a table or rest It above which isadjustably supported the X ray tube T by means of a post or standard, which is arranged at one side of the table.

This post, according to the present err-- ample, is movably supported by arms 11', 11 on suitable guides 12, i2 and is adapted to be reciprocated longitudinally of the table by means of a crank arm 13 driven from a suitable source of power (not shown). Proacress the table and suitably fi ed to an upper part of the post is a horizontal mounted the X-ray tube or other source of rays by means of carriage 15 or the like. This carriage, for purposes to be hereafter described, lay be fed transversally of the table on its guide 14 through a screw spindle 16, which works in a nut 17 provided at and fixed to one end of said carriage. The screw spindle is rotatively borne in bearings 18, 19 provided at the ends of the guide 14 and is operated through the medium of bevel gears E20 21. The bevel gear 21 is fixed on a vertical spindle 22 rotatively supported at its ends in brackets 23, 23 (Figs. 1 and 2 Fined to and projecting from the post 11 below and parallel to frame 14-, is another frame or guide M'eXtending above and across the table R and on whicl'l slidably support' ed a screen or diaphragn'i of suitable opaque n'iaterial through r-chich the r not pass, such as lead in case of X or radioactive rays, and which is provided with a slit Qt extending transversallythereof. This slit forms a passage for the rays eini d from the tube, as will be hereinafter described and may be made adjustable ifl-SlZO in any suitable manner not shown) lu'unediatel below the screen or diaphragm 25,1 provide a second screen or diaphragm 2? arranged i'larallel to the former and extend tra sversally of and substan-.

tially over the entire width of the table or rest R. This screen is provided with a slit 28 estending at a right angle to the slit- 26 and substantially throughout the length of the diaphragm and is slidably supported on guide rails 29 fixed by arms 30 to the table R. In order that the rays be directed in a Ill) converging or diver ing manner, according to the method hereinbefore described and illustrated in the diagrams Figs. 35, the move ments'of the diaphragms must be coordinated with the movementsof the source of rays in such a way, that the passage of the rays will constantly lie on a straight line swinging around the desired focal point. To this end, according to the present example, the followlng construction is used The diaohra 'm and the carriage 15 of l a o i the tube T are operatively connected by vertlcal oint-s 31 to parallel arms 32, 32, which in turn are connected by universal oints 31 ton telescopic pendulum 33 fulcrumed by a ball or other universal joint 33 to a vertically adjustable bracket 34: jn'o ectingfrom one side of the rest B; On the opposite side of the rest R. a second telescopic pendulum 34 is 'adjustably fulcrumed with its lower end at and connected to a bracket 36 pro ect- 1ng from the post 11, An intermediate telescopic sect-ion. 34: of said pendulum is con nected at 27' to said second diaphragm 2'7.

, tances, as shown in Fig. 4, and so that the I beam of rays passed through the rectan agular intersections of the slits 26 and 28 will always be directed towards point located on a con tinuation of the axis of the fulcrum 35. The particular position of the focal point on this line depends on the initial relative position of the source of rays T and the diaphragm 25, which, according to Fig. 1, would be nearly in the center of the table. The to and fro movement ofthe diaphragm 25 together with the post 11 and the source of rays T, as carried out in a direction parallel to the length of its slit 26, gives the same result, as if this diaphragm would be stationary'during the to and fro movement. It introduced only for purposes of convenience, inasmuch as it permits the employment of a smaller diaphragm. During one stroke of the to andv fro movement, the beam of rays remains in one plane and only a narrow layer of the body is radiated through. V

In order to pass through the whole body, after every stroke of the to and fro movement, steps must be made by the source of rays'T and the diaphragm 25 iua direction at right angles to the pendulous motion in accordance with the diaphragm shown in Fig-I3. These intermittent displacements of the source and diaphragm are accomplished according to the present example through the medium 'of the screw spindle 16. which is adapted to advance ti 2 carriage 15 transversally of the table at the end of each stroke a small oistance. To

this end,-the spindle 22 from which motion is transmitted to the screw spindle 16 through the bevel gears 20, 21 carries at its lower end a star wheel36 or the like and projecting from the corresponding side of the rest It and near each end thereof 1s a finger or pawl 37, 3'7 projecting into the longitudinal path of said wheel. the star wheel, during the reciprocation of the post 11, reaches the finger at either end, it receives a short turn, which it transmits to its spindle 22 and thence to the screw spindle 16 as a result of which the tube T will make a short advance transversally of the table R at the end'of each stroke. This short displacement of the tube will cause the pendulum 33 to swing on its fulcrum 33' and as a result thereof, the diaphragm 25 will be pulled in the same direction synchronously with said tube, but a distance shorter than that ofthe tube dis Jlacement in aro ortion to their distances from the fulcrum, and thus the, rays passing the-slit 26 will again be in a plane going to the previous focal point The diaphragm 25 has its slit adjusted to such a width, that-the displacement of the diaphragm after every stroke will be equal (21(- actly to this width and so all consecutive layers of the body without any interruption andcoverlapping will be step by step radiated through,

From the foregoing, itwill be seen that by the described combined movements of the t-ube'and of the two diaphragms25 and 27, the diaphragms moving in the same direction as the tube, the rays Wlll be made to con crums, 33,. 35; 1

p In order to cause the rays to, diverge, the movement of the diaphragms 25, 27 must be made to proceed in opposite directions to those of the tube T. To -accomplish tl is, according to the present enample shown somewhat dia grammatically in F1 3;; 1 the pendulum33 has fulcrumed to its upper end. a doublearmed lever 36" the free end of one arm of which is connected to the arm 32, of

3 32 of the diaphragm 25. The diaphragm. 25

being initially positioned nearthe side of the table R opposite to that at which the tube T is arranged, the arm 32 is' made inthis case correspondingly shorter. Onthe other hand, the telescopic pendulum 34 of the diaphragm 27 has its upper end pivoted centrally to an arm 37 'whose ends are connected to'the tube carriage and the diaphragm 27.'

"It will be seen that while the tube T reciprowas longitudinally, the diaphragm 27' will move in opposite direction longitudinally thetahle and when the tube-is displaced e the radii of. said pulleys).

transversally at the end of" each stroke, the diaphragm 25 will move in a direction opposite thereto.

In Figs. 7 and 8, a modification is shown whereby the covering of a surface by the rays is elfected by simultaneous circular and radial movements of the tube and of a diaphragm, resulting in a spiral motion, accordto the diaphragm in Fig. 6. To this end, the carriage 15 of the tube T may be slidably suspended. from a horizontal frame 38, which is fixed to a vertical spindle 39 journaled in the ceiling. as at all. A second frame 41 for the slidable support of a diaphragm 25 5a]:- ranged parallel to and below said frame 38 is rigidly suspended from the latterby rigid arms 42. The spindle may be rotated from a suitable source of power (not shown) through gears 43,,l4: or the like. On a support 45 or thelike also fixed to the ceiling are fixed centrally relative to the spindle 39 two pulleys 46, 4.7 of diilerent diameters to one of which is attached one'end of a cord 4C8 or the like connected, as at T8 to the carriage 15 of the tube and tethe other of which is attached one end of a cord 49 connected to the carriage of thediaphragm- 25 as at 49. Both carriages may be under the is fluence of springs 50, 50" or the like. hen the spindle 39 and consequently the frames 38 and ll are revolved, the tube T and diaphragm 25 will be n'ioved circles at. the axis of said spindle. Simultaneously the cords 48, 4:9'will be caused to wind around the two pulleys and thereby the tube T and the diaphragm 25 will describe spirals with ,difierent radial velocities, according to the ratio of the diameters of the two pulleys. In order to radiate through the whole body without intermissions or without overlapping of the neighboring circles of the spiral, the width 01"" the diaphragm slit in radial direction must be equal exactly to the difference between the circumferences of the pulleys t6 and .7 (21r(Rr), if R and 7 denote When the diaphragm 25 moves radially in the same direction as the tube, the rays will be caused lo convergc towards a point located below the diaphragm.- For causing the rays to diverge from a focal ioint located above the diaphragm, the diaphragmwill have to radially mrrve in opposite direction to thatof thc i'ube I r11 4 connecting the cord leading to the diaphragm This jean be readily accomplished by to the right side of the latter over two pulleys on the right sideof the frames 41 and shown). so that while the tube will move towards the ax s, the diaphragmwill more away from it. I

It is also obvious that the swinging move ment of any of the .pendula'33 and 34' may be'eifected by electro-magnets, and so all movements oft-he tube T and of the other diaphragm 25, as in the modification shown in F gs. 1 and 2, may be obtained in a purely electro-magnetic way. Thus, according to Fig. 9, the pendulum 3i, which causes the reciprocation of the diaphragm 27 may be attached to the rods 51, 51 sliding in thein 4- tel.

sin'iulianeously but alternately. When alterr current is used, the rods 51, 51 may a :nt magnets or electro-magnets By such arrangement, me construction and the reversing of the movements of the diaphraglns are considerably simplified.

A further simplification of my methodand ap ratus. when applied to X-rays, may be obtai. cd by the following construction Since the source of the rays in the case of X-rays is the spot where the beam of the cathode rays (electrons flying from the cathode) strike the target of the anticathode, the movement of the source of rays may be of fected by alternate deflections of the cathode rays. To this end, the tube T may be so con structed that front of the cathode 53 (Figs. 10 and 11), (or the filament in the case of a Coolidge tube), an electro-magnet 54 is provided with the magnetic field in a vertical direction. Opposite the cathode, I provide an elongated anticathode 55. On energizing the electro-magnet by an alternative current, the cathode rays will perform a pendulous motion in thehorizontal plane so that the impact spot of the cathode rays, which is the source of the X-rays, will be caused to oscillate. This will replace the mechanically cffected reciprocating movement of the tube T heretofore described. The corresponding movement of the diaphragms can be in such case accomplished by means of an electromotor moving synchronously with the same period as the alternating currentfeeding the fed b electro-magnet 54 or by means of an electrotant and equal sources of rays 61, 62, and 63 shown with a system of diaphragm plates so arranged that all the beams of rays are (ll rected to one common focus 69. Owing to the V fact that the upper plate 64 is provided with three slots a separate set of diaphragm plates for each beam of rays is not necessary in this particular modification.

This same Fig. 12 also shows the focal point located within the body being irradiated;

that is, within 6'7, and illustrates the use 0 the invention for treatment of internal pathological conditions rather than for the photographingof such conditions. Assume some abnormality. located deep within a body 67 and located at point 69. Should it be desired to destroy or treat the abnormality with powerful rays and at the same time avoid injur'y of the surrounding healthy'tissue the ar-.

2. A method of focalizing rays emitted,

from a source of radiantenergy to a predetermined focal point consisting in moving relatively to each other asource of rays, one or more perforated plates serving as a. dia phragm, and the recipient of the rays at such ratios of speed that said source and the passage left by the plate on plates will always be on a straight line extending throughthe predetermined focal point. 3. A method of focalizing rays emitte from a source of radiant energy to a predetermined focal point which consists in operatively connecting for relative movement a source of rays, one or more plates collectively forming a diaphragm and the recipient of the rays, so that when one of these elements is moved, the others connected to it will move at such ratio thereto that the source of rays and the passage through the plate or platesform ing the diaphragm will always remain on a straight line extending through the prede,-. termined focal point.

4. A method of focalizing rays emitted from a source of radiant energy to a predetermined focal point consisting in moving the source of said raysand a system of plates with elongated openings forming a diaphragm tranversely to the path ofthe rays in two directions at an angle to each other and at such ratios of speed that the source and the openings in the plates will always remain on a straight line extending through the predetermined focal point.

5. A method of focalizing rays emitted from several sources of radiant energy to one predetermined focal point consisting in providing for each source of rays a set of narrow openings in a system of diaphragms coordinated thereto to pass the rays emitted by said source, placing said sources and diaphragms in such relative positions that all rays passing through the diaphragms will be directed to the predetermined focus and in moving said sources and systems of diaphragms syn chronously and at such raties of speed that every source and the opening in the system,

of diaphragms coordinated with that source shall always remain on a straight line passing through the predetermined focus.

ii. A method of focalizing rays emitted from a source of radiant energy to a predetermined focal point consisting in moving the source transversely to the pathof the rays and in two directions at anangle to eachother and 7111 coordinating with said. source two superposed diaphragms provided with slits intersectin each other at an an le and arranged in the path of said source, moving each diaphragm transversely of its slit syn-' chronously with a corresponding movement.

of the source but at such ratio of speed that the passage formed by the intersecting slits will always lie on straight line connecting the source with the predetermined focal point. r d

' 7. method of focalizing rays emitted from a source of radiant energy to a predetermined focal'p'oint consisting in imparting to the source a step by step movement and also a movement at right angles thereto, both movements taking place at different times with respect to each other, and in moving,

a system of diaphragms having openings therein synchronously and substantially parallel to the movements of the source but at such ratios of speed that the opening left by the system of diaphragmaand the source will always 7 be on a straight line passing through the predetermined focal point. 7

8. A t method of focalizing, rays emitted from asource of radiant energy to a prede termined focal point con'sisting in imparting to the source a step by step movement and also a movement at *ight angles thereto, both movements being transverse to the path of the rays and taking place atdifferent times with respect to each other, and in moving a system iof diaphragms having openings therein synchronously and substantially parallel to the movements of the source but at such 1 ratios of speed that the opening left by the system of diaphragms, and the source will always be on a straight line passingthrough the predetermined focal point, the openings 'left by-t-hc system of diaphragms being equal the object to-be irradiated.

11. An apparatus comprising a source of radiant energynneans for moving said source, and a movable slitted diaphragm system 0perativel-y so connected thereto that when the sou-roe is moving, said diaphragm system will move synchronously with and relatively to the latter and the transmitted energy willbe guided towards a predetermined focal cen ter.

' 12; An X-ray apparatus comprising a tube,

means for reciprocating the tube over a sta tionaryenergy recipient and for moving it at the end of each stroke in a direction transversely of said reciprocating movement, and

two superposed diaphragms each having a slit therein, said slits intersecting one another, means for connecting said diaphragms to said tube'to move synchronously with said two movements of the latter, said connecting means. comprising means for changing the amplitudes and velocities of the diaphragms in a desired ratio, whereby, when the tube is moved, the passage left by the. intersecting slits will move relatively to the source and the direction of the transmitted rays will change in a desired manner.

= 13. Anapparatus torusing rays of radiant energy, comprising a source of rays, means for reciprocating and moving the source at the end of each reciprocation in a direction transversely of the reciprocating movement, two superposed diaphragms of opaque material arranged in the path of said rays and each having a slit said slits intesecting-one another, means for transferring said reciprocating movement with changed speed and amplitudes to both said diaphragms and cluding pendula with adjustable fulcrums and whereby saidtwo diaphragms wil1 be caused to participate inthe reciprocatingmovement of'sai'd ca-rrier'and one of said diaphragms; will also be caused to participate in the transverse movement of said source carrier, sothat the-passage formed by the intersecting slits will always remain on a straight line with said source swinging around afocal center-predetermined by the positions of the tulcru-ms of said pendu'l a.

15. In an apparatus for focalizing rays the combination with a supportfor an energy recipient, of a movable sourceo'l? radiant energy, movable slitted dla-phragmsm the path of the energy radiating fromsaid source,

means for moving said source, means formoving said diaphragms and meansfor coordinating the speed and amplitudes of said movements to pass the radiant energy to the recipient at desired angles of incidence.

16'. an X-ray apparatus comp-rising a tube, means for-reciprocating the tube over a stationary energy recipientand for moving the tube at the end of eachstroke in a direction transversely of said reciprocating movement, a diaphragm system between said tubeand recipient, havinga clear passage for rays in said system and means for transferring said movements-ofthe tubeto said diaphragm sys- Y tem with a difierent amplitude and velocity,

whereby when said tube is moved, said passage left by said diaphragm system for the rays will move proportionately to the source and the transmitted rays will change their direction continuously and in a desired manner.

' MOSES JACOBSON.

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