US1688675A - Method and apparatus for taking synchronized radiograph exposures - Google Patents

Description

was, 1923.; 1,688,675.

. c. N. W EYL METHOD AND APPARATUS FOR TAKING SYNCHRONIZED RADIOGRAPH EXPOSURES Filed March 5, 1925 2 sheds-sheet 1 WITNESSES I INVENTOR:

' UharEe-s NiWz E9 I BY W ATTORNEYS.

@ch 23 ig C. N. WEYL METHOD AND APPARATUS FOR TAKING SYNGHRONIZED RADIOGRAPH EXPOSURES 2 Sheets-Sheet INVENTOR- Uharlas N. Wgyl, BY KM ATTORNEYS.

Filed March 5, 1925 WITNESSES r 266W j a 956/ Patented Oct. 23, 1928.

UNITED STATES PATENT OFFICE.

CHARLES N. WEYL, OF PHILADELPHIA, PENNSYLVANIA.

METHOD AND APPARATUS FOR TAKING SYNCHRONIZED RADIOGRAPH EXPOSURES.

Application filed March 5, 1925 Serial No 13,175.

This invention relates to certain improvements in apparatus for the taking of radiograph exposures, and more particularly to devices for synchronizing the taking. of such 5 exposures at predetermined phases of the movement of organs of the human body.

One of the objects of this invention is to provide means by which the radiograph exposure may be made at any predetermined point in the movement of a human organ.

Another object is to provide means for the timing of radiograph pictures of the human body at any desired phase of the human heart cycle.

Another object is to provide means for the making of radiograph pictures of the human chest at a predetermined position of the lungs and at any desired phase of the human heart cycle.

A further object is to provide means responsive to the arterial or venous pulse and determining the instant of exposure in the taking of radiographs illustrating the position of the organs of the human body at any desired phase of the human heart cycle.

With these and other objects in view, there are represented on the accompanying drawing two methods of obtaining this synchronization, in which- Fig. I is a diagrammatic view of a preferred form of the apparatus employed;

Fig. II is a view showing the arrangement of the lag mechanism for determining the delay in the operation of the device; and

Fig. III is a diagrammatic view of a modified form of the device.

In the taking of radiograph exposures of parts of the human body, more particularly of the chest and heart, it is desirable, and in 40 most cases essential, to produce clear, welldeiined X-ray negatives, showing sharp focuses and fine detail. This requirement is made by diagnosing physicians. research physicians, and physiologists in order that 45 the results of the radiogra h, and their deductions therefrom, shall be accurate. In

.taking X-ray plates of the chest it has been found that even though the patient be kept quiet and without breathing durin the ex- 5 posure, the motion of the heart and of thelarge blood vessels during the X-ray exposure frequently causes a blur in the resulting negative, which ruins the photograph for scientific purposes. The movement of the heart 6 is not uniform, but varies from systole to diastole at regular intervals. During the diastolic period, the heart is at rest for a short time. An exposure made during this part of the heart cycle, therefore, shows a maximum of clearness and definiteness. Further, in the study of the heart action. whether of normal or abnormal, it is desirable to be able to make a series of X-ray exposures at known phases of the heart cycle, to show the changes taking place in .the size, shape, etc., of the heart during any given cycle.

According to this invent on, either the arterial or the venous pulse is utilizedto release the exposure device of the radiograph machine. The pulse movement is utilized to deflect a be m of light in order to illuminate a photo-se 1 itive cell. The variation of this cell under the influence of the illumination determines the passage of a minute electric current which is amplified for employment in a mechanism which will be hereinafter designated as lag relay, which effects the exposure a predeterminable time interval after the actuation of the mirror under the influence of the pulse movement. This interval of delay may be adjusted and calibrated by the operator at any time. A preferred means for effecting the exposure is a switch, in the primary circuit of the X-ray apparatus, which is subject to the direct control of the lag relay.

In Fig. I of the accompanying drawings, 1 represents a source of light with a focusing mirror 1 to direct a substantial portion of the radiation from the source 1 through the compound condensin lens 2 and upon the concave lens 3. whic serve to collect the light and to render the light rays parallel. 4 is a small and very light mirror of the type ordinarily employed in highly sensitive instruments, such as galvanometers; it is suspended for movement about an axis at right angles to the axis of the light beam from the lens 3 by any means such as phosphor-bronze suspension ribbon or the like, which is indicated diagrammat'lally at 5.

The applicator B includes a funnel-shaped element 14; which may be placed in contact with the neck of the patient immediately over the carotid artery, or in contact with the chest of the patient over the apex of the heart. A connecting tube 13, of rubber for example, furnishes communication between the stem 14 of the funnel 14 and the attaching nipple 13 of the timing portion of the applicator apparatus. This nipple has as its other end a tambour 10 with a diaphragm 9 of thin rubber or the like mounted across its open end. A T-connection on the nipple 13 terminates in a minute orifice 11 which may be regulated by a valve 12. At the center of the diaphragm 9 is mounted a small spur or strut 8. Rigidly connected with the posite the strut 8. The free body of the tambour 10 is a pivot seat 7 to receive a sensitive lever 6 which depends oplower end of the offset portion 6 outer end of this is in light contact with the lever 6 is provided with an at right angles thereto: the offset portion 6 'mirror 4 and furnishes an actuating device for the same. The adjusting screws 6 and 6 are dis osed on the frame of the applicator to enable the operator to adjust the limits of movement and the ment of the lever 6.

The light from the source 1 is thus thrown upon the mirror 4 and reflected thereby along the course shown at 15, when the mirror is in the position shown in full lines. 16 indicates a housing having an openin 16 in the face thereof. Disposed within t e housing and opposite the opening is a photo-electric cell 17. This cell may be of any type in which a current of electricity is generated or controlled under the influence of illumination from the outside source 1. It is provided, for example, with an anode 19 and a cathode 20. The mirror 18 on the housing 16 serves to point of initial movereflect all the light from the beam 15 onto the photo-electric cell 17, when the beam strikes the mirror 18.

A three-element electron discharge tube is shown at 2L and has the cathode or filament anode 23 and grid 22. A grid biasing battery 49 is connected across the grid potentiometer 27 to enable the operator to adjust the electrical potential on gard to the filament or in other words to make the grid 22 suficiently negative with respect to the cathode 24 so that no current will flow from the anode 23 to said cathode when no li ht is falling upon the photo-electric cell 17. T e high resistance 25 serves as a grid leak or conductive shunt between he grid 22 and cathode 24. The cathode 20 of the photoelectric cell 17 is connected to the grid 22 of the electron discharge tube 21 through the potentiometer 27; the anode 19 of the cell 17 is connected through the primary battery 47 and the plate battery 48 to the cathode 24 of the electron discharge tube 21. The anode 23 of the discharge tube 21 is connected through a milliammeter A and the coil 28 of a sensitive relay to the positive terminal of the plate battery 48.

The relay coil 28 is adapted to energize a spring-hel armature 29 which is associated with a stationar contact 30. A foot switch 52 is provided fbr the operator as a means of cqntrollin the flow of current through the intermediate system between the relay 28 and the .lag re ay to be hereinafter dethe grid with re- 38 to move,

scribed. This foot switch 52 is connected to a battery 54 and thence to the exciting coil 34 of the lag relay, from the other terminal of which coil an electrical connection extends to the stationary contact 30. The lag relay has associated therewith a spring-held switch blade 35, which in turn is in operative relation with a stationary contact 31. The blade 35 is electrically connected with the armature 29 and with the remaining terminal ofthe foot switch 52. The stationary contact 31 for the switch blade 35 is electrically connected with the stationary contact 30 of the relay 28.

The coil 34 of the lag relay has associated therewith a plunger armature or core 36 which is slidably mounted in a hollow shaft or hub 36 of the gear wheel 37 and is adapted for free displacement rotatably and axially in the said hollow shaft. In its axial movement toward the left in Fig. I, upon excitation of thesolenoid 34, the plunger 36 comes in contact with the pivoted switch blade 35 and forces the latter into electrical contact with the stationary member 31, thus closing the circuit which eliminates the moving contacts 29, 30 of the relay 28. Upon de-energization of the solenoid 34, the switch arm 35 is returned to the inoperative position by the recoil spring 55.

The gear wheel 37 meshes with a smaller gear 50 mounted on a shaft 5O which may be driven by an electric motor, a clockwork mechanism, or any other uniformly driven mechanism'as at M.

Mounted on the outer end of the plunger 36 is a disk 38, bearing a contact element 39 on the face thereof, and adapted to be carried into frictional contact with the gear wheel 37 when the plunger is actuated. The disk 38 and the plunger 36 are normally held against rotation owing to the slight frictional contact with the plate 37 and the hollow shaft 36 so long as the solenoid 34 is de-energized, by a coil spring 53 which is connected to a fixed point of the frame at one end and at the other is by way of illustration connected to the rear of the upstanding contact element 39. This spring counteracts any tendency of the disk and brings it after de-energization of the solenoid 34 to a predetermined rest or initial position. A conductor 53' places the contact element 39 in electrical connection with one pole of the source of electricity 56.

The arm 51 is mounted for rotation about a 'pivot co-axial with the plunger 36 and the hollow shaft 36. This arm 51 carries an insulated contact member 40 in operative relation to the contact 39 on the insulating disk 38. The conductor 40" places this contact 40 in electrical connection with the solenoid 41 and thence with the battery 56. The solenoid 41 is utilized, in con 'unction with its armature 42 and the switch blade 44 to close the primary circuit 45, 46 of an X-ray apparatus, said circuit including an appropriate source of current 45. A return spring 57 is provided for the switch blade.

The method of operation of this apparatus is as follows: The operator, after adjusting the X-ray tube X and sensitized plate Z with regard to the patient P, places the funnel 14 over the carotid artery or the apex of the heart of the patient, and opens the valve 12 just sufficient to permit the return of the diaphragm 9 to its normal position between heart pulses. The adjusting screws 6 and 6 may be assumed as having already been adjusted to place the lever 6 in condition to move the mirror 4 at ample.

the moment of systole of the heart, for ex- The operator then starts the uniform speed mechanism, which drives the pinion 50 and thence the gear 37 at a uniform predetermined rate of speed. The operator now, at any moment, closes the foot switch 52.

The pulses in the artery of the heart cause the column of air in the applicator B to vibrate in unison therewith and thus distend the diaphragm 9 outwardly, until the strut 8 pushes the lever 6 away from the adjusting screw 6 and tilts the mirror into a position such as that shown in dotted lines. While the mirror is at rest, the light beams reflected therefrom pass along the lines indicated at 15. When the mirror has been moved in the manner just described into the position shown in dotted lines, the beam of reflected light is likewise moved to the position shown at 15 in which it enters housing 16 and falls upon the photo-electric cell 17 The photo-electric cell responds thereto with the result that current flows from the anode 19 to the cathode 20 through the grid leak 25 and batteries 48, 47. When light thusfalls upon the cell 17, the photo-electric current in passing through the resistance 25 reverses the bias of the grid 22 and makes it positive with respect to the cathode 24. This causes a current to flow from the positive pole of the batter 48 through the relay coil 28, the anode 23 an the cathode 24 back to the negative pole of the battery 48.

If the foot switch 52 be assumed as closed, the-current will flow under such conditions, from the battery 54 through the switch 52, the contacts 29, 30, the solenoid 34 and back to the battery 54. The plunger 36 will therefore be drawn to the left and the contacts 35, 31 closed, and the energization of the solenoid 34 will be maintained irrespective of the position of the arm 29.

The disk 38 which has theretofore remained stationary with regard to the rotating gear 37, is simultaneously drawn against the gear, and is rotated by frictional contact at the same speed of rotation. tion of the gear 37 being known, the operator may calibrate the distance between the contacts 39 and 40 in terms of angles from the the openings 16 of the The speed of rotaaxis of this gear, and thus predetermine the exact time at which the contact 39, now moving in unison with the gear 37 will encounter the adjusted contact 40.

Upon closure of the contacts 39 and 40, the circuit is established from the battery 56 through these contacts, the solenoid 41, and back to the battery 56. The solenoid 41 thereupon determines the closure of the oil switch blade 44 with contact 43 and results in the flow of current in the primary of the X- ray transformerfl. In known manner, the current in the primary of this transformer causes the emission of X-rays from the tube X to produce the radiograph exposure.

When the solenoid 34 is de-energized again, the plunger 36 and the disk 38 are relieved from their frictional contact with the gear 37, and are returned by the spring 53 to the rest or initial position.

In the modified form of my apparatus shown in Fig. 111, instead of utilizing the arterial pulse, I use the minute electric current generated by the heart itself. It is known that the heart beats are associated with certain transient electromotive forces which maybe measured by a sensitive galvanometer or cardiograph. To this end, I provide a pair of plates 100, 101 for application respectively to opposite extremities of the patient, for example to the right arm and left foot; said plates being preferably moistened with a suitable conductive solution to insure good electrical contact. These plates 100, 101 are connected by conductors 102 and 103, respectively, to the grid 104, and the cathode 105 of an electron discharge tube 106. These two elements are shunted by a grid leak 107, in known manner. The anode 108 of the discharge tube 106 receives current from the cathode in known manner, at the moment of the heart beat and constituting a modified current resembling the original electro-motive force associated with the heart beat. This current is led for example through a Duddell oscillograph represented diagrammatically at D, and returns through a plate battery 109 to the cathode 105 of the discharge tube. The suspension wires 110 of the oscillograph D carries a small mirror 1.11, which is utilized to reflect a beam of light on to a photoelectric cell at the moment of systole. This photo-electric cell and the remaining apparatus may be identical with that shown and described with relation to Fig. I.

It is obvious that this invention is in no wise limited to the precise arrangement and details shown, but that it may be employed to obtain clean cut, sharp radiographic pictures of any portion of the body uninfluenced by extraneous voluntary or involuntary movements, and in particular that in the taking of pictures of the human chest, the apparatus may be set for exposure at any given moment of the cycle of the human heart, so that successive pictures may be taken at different successive positions of the heart.

Having thus described my invention, I claim:

1. In a synchronizing apparatus for radioraph exposures, an applicator acted upon y a movement of a living body, a timing device adapted to be started upon the actuation of said applicator, and means operated by said timing device after a predetermined 1nterval to eifect the radiograph exposure.

2. In a synchronizing apparatus for radlographic exposures for pictures of the llv ng body, an X-ray tube and power supply l ne therefor, a primary switch in said line, a timing device to close said switch a predeten mined time interval after its oWn actuation, and means operated upon the occurrence of the arterial pulse of the body to actuate said timing device.

3. In a synchronizing apparatus for rad1ograph exposures, an applicator including an element ada ted to be placed in relation to a part of the ody demonstrating the arterial pulse, a diaphragm adapted to be actuated in accordance with said pulse, and a lever actuated by said diaphragm at a predetermined amplitude of movement thereof; a source of light, a photo-electric cell, and a mirror adapted to be actuated by said lever to refleet the beam from said source onto said cell; a timing device adapted to energizethe X- ray tube at a predetermined time interval after its own actuation, and means controlled by said photo-electric cell to actuate said device.

4. In an apparatus for cardiographic in vestigations, means defining an air column supported upon and vibrated in unison w th a part of the body demonstrating the arterial ulse of the patient, a diaphragm vibrated by said air column, a source of light, a mirror photo-electric cell, a lever actuated at a prede termined amplitude ofvibration of said diaphragm and adapted to move said mirror to reflect the beam onto said cell, and means to indicate the occurrence of such amplitude.

5. In an apparatus for cardiographic investigations, timing means to close a circuit a predetermined time interval after actuation of said means, and means responsive to the arterial pulse of the patient to actuate said timing means.

n an apparatus for making radiographic exposures by means of an X-ray tube, timing means to close the power circuit of the X-ray tube a predetermined time interval after actuation of said means, and means operated in unison with the arterial pulse of the patient to actuate said timing means.

in the path of a beam from said source, a

7. In apparatus for taking radiographic exposures, a pneumatic system sensitive to the blood flow pulse of the patient, a timing system adapted to be started by said pneumatic system upon actuation from the pulse to determine a regulatable delay, and means energized by said timing means after said predetermined interval to eliect the radiographic exposure.

8. In apparatus for taking radiographic exposures, means sensitive to the blood flow pulse and including a diaphragm subjected to the movement of a column ofair to give physical response to said pulse pressure equalizing means to permit the return of the diaphragm to normal position between successive pulses, timing means adapted to be started by displacement of the diaphragm to determine a regulatable delay, and means energized by said timing means after said predetermined interval to effect the radiographic exposure.

9. In an apparatus for making radiographic pictures in synchronism with periodic movements of the body, means defining an air column vibrated in unison with the said movement, a diaphragm vibrated by said air column, and means actuatable by said diaphragm to efi'ect the exposure.

10. In an apparatus for making radiographic pictures of the living body by means of an X-ray tube, timing means to close the power circuit of an X-ray tube a predetermined time interval after actuation of said means and means operated by a cyclic movement of the body to actuate said timing means.

11. In an apparatus for making radiographic pictures in synchronism With periodic movements of a body, means defining an air column vibrated in unison with the said movement, a diaphragm vibrated by said air column, a conduit having an adjustable crosssection and establishing communication be tween the said column of air and the atmosphere, and means actuatable by said diaphragm in its movement to ellect the exposure.

12. In an apparatus for making radiographic pictures in synchronism with periodic movements of a body, a member movable by the body, a lever oscillated by said member, a mirror to be rocked by said lever, a source of light to project a beam upon said mirror, a photo-electric cell, a screen, and means to adjust the end positions of movement of said lever so that at one end position the mirror will reflect the beam onto said cell and in the other position the mirror Will reflect the beam onto said screen. I

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania, this third day of March, 1925.

CHARLES N. WEYL.

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