US3515873A - Method and apparatus for analyzing and calibrating radiation beams of x-ray generators - Google Patents
Method and apparatus for analyzing and calibrating radiation beams of x-ray generators Download PDFInfo
- Publication number
- US3515873A US3515873A US697233A US3515873DA US3515873A US 3515873 A US3515873 A US 3515873A US 697233 A US697233 A US 697233A US 3515873D A US3515873D A US 3515873DA US 3515873 A US3515873 A US 3515873A
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- United States
- Prior art keywords
- generator
- oscilloscope
- traces
- calibrating
- analyzing
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/16—Measuring radiation intensity
- G01T1/24—Measuring radiation intensity with semiconductor detectors
- G01T1/247—Detector read-out circuitry
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T7/00—Details of radiation-measuring instruments
- G01T7/005—Details of radiation-measuring instruments calibration techniques
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05G—X-RAY TECHNIQUE
- H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
- H05G1/08—Electrical details
- H05G1/26—Measuring, controlling or protecting
Definitions
- the invention comprises a portable apparatus which A accomplished.
- the apparatus includes a combination of a radiation detector preamplifying assembly compactly arranged in a box-like housing and with a cable carrying conductors extending from the housing to a power supply and to a dual sweep oscilloscope.
- the preamplifying assembly includes a pair of semiconductor detector elements, one of which is relatively partially shielded to the radiation "beam, the other of which is relatively non-shielded. The respective signals from the detector elements are amplified and transmitted simultaneously to the oscilloscope while the elements are subjected to the beam of radiation.
- the method of calibration includes providing a graph, or a photograph of a pair of traces on the oscilloscope, representative of a properly calibrated generator, and then observing the ratio of pulse heights shown on the oscilloscope while a generator under calibration is being operated, and finally adjusting such generator until the percent of transmission through the respective detector elements coincides with a standard peak voltage indicated by the graph or until the traces on the oscilloscope coincide with the traces shown on the photograph.
- the graph or the photograph are prepared using the same apparatus which is later used in calibrating other generators to the predetermined standard. Observation of the traces on the oscilloscope, or of photographs made of the same, provide information from which malfunctioning of the generator may :be deduced.
- FIG. 1 is a diagrammatic view indicating a typical usage of the invention.
- FIG. 2 is a top plan view of the housing for the preamplifying assembly, with the top cover removed, and with the detector elements and the amplifier mounts shown schematically.
- FIG. 2A is an inside view of the cover for the housing of FIG. 2.
- FIG. 2B is a side elevation view of the bottom plate for the housing of FIG. 2.
- FIG. 3 is a wiring diagram for the assembly contained in the housing.
- FIG. 4 is a view of the oscilloscope graticule showing traces similar to those of a properly calibrated and operating generator.
- FIG. 4A is a view of the graticule showing traces deviating from a properly operating generator and illustrating a situation wherein a faulty high voltage rectifier is present, and
- FIG. 5 is a graph for reference to determine the peak voltage of the calibrated machine following an inspection of the traces such as indicated in FIG. 4.
- a conventional X-ray generator indicated generally at 10 is mounted for movement above a table 11 on which a patient is to be placed.
- a portable apparatus preferably in the form of a vehicular support, includes a conventional dual sweep oscilloscope 12, a conventional decade type glow tube timing means 13, a camera 14 preferably of the Polaroid type pivotally mounted adjacent the graticule of the oscilloscope, a
- a cable 18 having a length suflicient to displace the operator at a safe distance from the radiation beam extends from the assembly 16 to the power supply.
- the oscilloscope which forms a significant feature of the combination of apparatus may be of any conventional type, as for example the Type 545B dual sweep oscilloscope available from Tektronix Inc., Beaverton, Oregon,
- the housing for the preamplifying assembly comprises a generally rightparallelepiped form of box having a side plate 20 with an integral side wall 21 through which cable 18 extends, and with the plate 20 providing support for block structures indicated at 22, 23 and serving as the mounting of the operational amplifiers, later to be described.
- Mounted side by side at a suitable spacing, for example about 1.5 cm., and supported from plate 20 in any suitable manner are a first detector element 24 and a second detector element 25, the latter being shielded by a suitable sheet 26 of beam filtering material such as aluminum.
- Another member providin walls 27, 28 for the box is adapted to engage with plate 20 and wall 21 when the box is assembled.
- a bottom plate 29 having a pair of threaded rods 30, 31 projecting upwardly therefrom is adapted to abut against the lower ends of the box walls, and the rods are adapted to extend through holes in the top plate 32 and to be engaged by nuts or other fastening means disposed on the upper surface of the top plate.
- Afiixed to the inside surface of the top plate is a sheet 33 of shielding material such as lead and projecting inwardly from the top plate is a U-shaped wall 34 of similar shielding material which is adapted to prevent backscatter into the detector elements.
- the sheet 33 has an opening therein corresponding to the confines of wall 34 thus to provide a window 35 through which the beam passes and which window is covered by the outer layer of top plate material.
- the walls, bottom and top plate are constructed of thin gauge aluminum sheet.
- the preamplifying apparatus includes the detectors 24 and 25 comprising semi-conductor detector elements of the lithium-ion-drift type, such as type 5X5-LID-1000-100A available from Solid State Radiations, Inc., Los Angeles, Calif, and which are fed in parallel at a suitable positive DC. voltage from power supply 15. As radiant energy is absorbed in the depletion layer of these detectors their resistance is decreased and they can be used to develop an electrical signal proportional to the absorbed radiant energy.
- the detectors 24 and 25 comprising semi-conductor detector elements of the lithium-ion-drift type, such as type 5X5-LID-1000-100A available from Solid State Radiations, Inc., Los Angeles, Calif, and which are fed in parallel at a suitable positive DC. voltage from power supply 15. As radiant energy is absorbed in the depletion layer of these detectors their resistance is decreased and they can be used to develop an electrical signal proportional to the absorbed radiant energy.
- the two detectors are substantially identical as regards their ratings and their construction, and both have a high quiescent impedence, for example about 10 megaohrnsv
- voltage dividers 40A are interposed and the signals developed at the load resistors which, for example, have a rating of 1 megaohm, are coupled directly into operational amplifiers 41, 41A connected as voltage followers.
- operational amplifiers 41, 41A connected as voltage followers.
- a signal ranging from about 0.1 volt for low PKV- low MA radiation to about 2.5 volts at high PKVhigh MA radiation of the generator 10 can be developed and transmitted to the oscilloscope through conductors 42 and 42A.
- the operational amplifiers are of a suitable type such as the SQ-l 0A units available from Nexus Reserach Laboratory, lnc., Canton, Mass.
- Feedback loops 45, 45A provide linear, consistent and distortion-free amplification of signals.
- Conductors 46, 46A leading to the power supply carry suit able current, for example, at about +15 volt DC, to the amplifiers as do conductors 47, 47A carrying about 15 volt DC. and conductor 48 carrying 0 to -15 volt D.C.
- Suitable control means on the power supply serve to regulate the settings of the respective potentiometers and variable resistors.
- the entire preamplifying assembly can be housed in a box as described having dimensions of about three to two by one inches.
- a preferred usage of the invention involves the prior preparation of a reference graph such as shown in FIG. 5 representative of the radiation absorption characteristics of the detector element combination and wherein the abscissa represents the peak generating voltages in kilovolts of radiation beams used in diagnostic radiology, and the ordinate represents the transmission of the beam through added absorber 26 as a ratio of the output signal of the shielded or first detector 25 so that of the nonshielded or second detector 24.
- the relative heights of the traces 50, 51 (FIG. 4) shown on the graticule 52 of the oscilloscope are determined and the ratio as a percent of transmission is plotted for the corresponding peak kilovoltage thereby to form a curve 53 for future reference.
- a photograph of the traces shown on the oscilloscope is taken by camera 14 to provide a permanent record of a properly calibrated and functioning generator against which comparisons with other generators may be made.
- the photograph serves further purposes in that it indicates waveform of the signals which upon analysis can be used to detect actual or incipient malfunctioning of the generator.
- the number of individual pulses indicative of the time of an exposure is displayed along the X-axis of the oscilloscope graticule.
- the time of the exposure is determined by counting the pulses on the oscilloscope or by the decade readout tubes of the unit 13 which show the number of impulses in any exposure. Normally, in a full wave, rectified, single phase unit type of generator there will be pulses per second.
- the timer of the generator will then be adjusted as part of its calibration.
- the generator in the event that the milliamperage of the radiation beam, which can be determined by known calculations from the amplitude of either of traces 50, 51 shown on the oscilloscope, should depart from the proper value as indicated by comparison with a trace from the standard calibrated generator, then the generator likewise will be adjusted in known manner.
- the oscilloscope traces from a generator being tested serve to indicate to a skilled technician the type of abnormality which may be present in that generator. For example, as shown in FIG. 4A, the 'dilference in heights of successive pulses and the displacement of the traces downwardly on the graticule is indicative of a faulty high voltage rectifier in the generator. The fact that four pulses, however, are shown on the trace would indicate that the timer of the generator is operating satisfactorily.
- the apparatus embodying the invention is particularly well suited for carrying out the described method steps.
- Camera 14 is pivotally mounted adjacent the graticule of the oscilloscope and when a photographic record of the traces is desired, it is moved into and clamped in operating position for rapidly taking the record.
- Use of a camera such as the Polaroid type permits the operator to obtain a permanent record in a short time.
- the entire apparatus moreover, is self-contained except for the readily detachable power conductors 17, and may be easily moved from one generator to another in a hospital, and into and out of storage.
- the method of calibrating an X-ray generator to secure a standard peak voltage of its radiation beam comprising, passing said beam simultaneously through a relatively partially shielded preamplifying detector element and through a substantially similar but relatively nonshielded detector element, depicting as exposure-rate time functions the output signals from said elements in the form of respective first and second traces simultaneously on an oscilloscope graticule, determining the ratio of the pulse height of said first to said second trace, and adjusting the generator until said ratio corresponds to a predetermined standard value.
- the method of calibrating an X-ray generator to secure a standard peak voltage of its radiation beam comprising, providing as a standard a comparative photograph of the traces of a dual sweep oscilloscope showing small and large signal outputs as exposure-rate time functions derived from passing a beam from a suitably calibrated X-ray generator simultaneously and respectively through a relatively partially shielded preamplifying detector element and through a substantially similar but relatively non-shielded preamplifying detector element,
- a portable apparatus comprising a radiation detector preamplifying assembly, a dual sweep oscilloscope, and a power supply for said assembly; said preamplifying assembly including a housing adapted to be located in the beam of said generator and containing a second detector element relatively partially shielded to said beam and a first detector element substantially similar to said first element but relatively non-shielded to said beam, and means for transmitting the respective small and large signal outputs as exposure-rate time functions from said detector elements, when subjected to said beam of radiation, to said oscilloscope to provide simultaneous traces on the graticule thereof, whereby the value of the peak voltage of said generator may be readily determined as a function of the ratio of the small to the large pulse heights shown by the oscilloscope traces.
- said housing encloses a pair of substantially similar operational amplifiers receiving signals from the respective detector elements and feeding said signals in amplified form to said oscilloscope through a cable extending through one side wall of said housing.
Description
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US69723368A | 1968-01-11 | 1968-01-11 |
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US3515873A true US3515873A (en) | 1970-06-02 |
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US697233A Expired - Lifetime US3515873A (en) | 1968-01-11 | 1968-01-11 | Method and apparatus for analyzing and calibrating radiation beams of x-ray generators |
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Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3864568A (en) * | 1972-06-19 | 1975-02-04 | Shm Nuclear | Automatic isodose plotter |
US3887804A (en) * | 1973-12-03 | 1975-06-03 | Us Health | Radiographic test stand |
US4361900A (en) * | 1980-11-20 | 1982-11-30 | Victoreen, Inc. | Radiation monitoring device |
US4400821A (en) * | 1981-04-10 | 1983-08-23 | Siemens Aktiengesellschaft | Apparatus for the measurement of the X-ray tube high voltage |
US4697280A (en) * | 1984-09-06 | 1987-09-29 | Wisconsin Alumni Research Foundation | Method and apparatus for the measurement of X-ray sources |
US4843619A (en) * | 1988-04-22 | 1989-06-27 | Keithley Instruments Inc. | Apparatus for measuring the peak voltage applied to a radiation source |
US8066713B2 (en) * | 2003-03-31 | 2011-11-29 | Depuy Spine, Inc. | Remotely-activated vertebroplasty injection device |
US8361078B2 (en) | 2003-06-17 | 2013-01-29 | Depuy Spine, Inc. | Methods, materials and apparatus for treating bone and other tissue |
US8360629B2 (en) | 2005-11-22 | 2013-01-29 | Depuy Spine, Inc. | Mixing apparatus having central and planetary mixing elements |
US8415407B2 (en) | 2004-03-21 | 2013-04-09 | Depuy Spine, Inc. | Methods, materials, and apparatus for treating bone and other tissue |
US8950929B2 (en) | 2006-10-19 | 2015-02-10 | DePuy Synthes Products, LLC | Fluid delivery system |
US8992541B2 (en) | 2003-03-14 | 2015-03-31 | DePuy Synthes Products, LLC | Hydraulic device for the injection of bone cement in percutaneous vertebroplasty |
US9381024B2 (en) | 2005-07-31 | 2016-07-05 | DePuy Synthes Products, Inc. | Marked tools |
CN106483554A (en) * | 2016-10-28 | 2017-03-08 | 中国计量科学研究院 | Detecting system |
US9642932B2 (en) | 2006-09-14 | 2017-05-09 | DePuy Synthes Products, Inc. | Bone cement and methods of use thereof |
US9918767B2 (en) | 2005-08-01 | 2018-03-20 | DePuy Synthes Products, Inc. | Temperature control system |
US10111697B2 (en) | 2003-09-26 | 2018-10-30 | DePuy Synthes Products, Inc. | Device for delivering viscous material |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2258593A (en) * | 1940-03-18 | 1941-10-14 | Lawrence F Black | Method of calibrating roentgenographic machines |
US3433954A (en) * | 1966-09-16 | 1969-03-18 | Atomic Energy Commission | Semiconductor x-ray emission spectrometer |
US3435220A (en) * | 1965-02-26 | 1969-03-25 | Industrial Nucleonics Corp | Dual channel radiation gauge for identifying material components |
-
1968
- 1968-01-11 US US697233A patent/US3515873A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2258593A (en) * | 1940-03-18 | 1941-10-14 | Lawrence F Black | Method of calibrating roentgenographic machines |
US3435220A (en) * | 1965-02-26 | 1969-03-25 | Industrial Nucleonics Corp | Dual channel radiation gauge for identifying material components |
US3433954A (en) * | 1966-09-16 | 1969-03-18 | Atomic Energy Commission | Semiconductor x-ray emission spectrometer |
Cited By (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3864568A (en) * | 1972-06-19 | 1975-02-04 | Shm Nuclear | Automatic isodose plotter |
US3887804A (en) * | 1973-12-03 | 1975-06-03 | Us Health | Radiographic test stand |
US4361900A (en) * | 1980-11-20 | 1982-11-30 | Victoreen, Inc. | Radiation monitoring device |
US4400821A (en) * | 1981-04-10 | 1983-08-23 | Siemens Aktiengesellschaft | Apparatus for the measurement of the X-ray tube high voltage |
US4697280A (en) * | 1984-09-06 | 1987-09-29 | Wisconsin Alumni Research Foundation | Method and apparatus for the measurement of X-ray sources |
US4843619A (en) * | 1988-04-22 | 1989-06-27 | Keithley Instruments Inc. | Apparatus for measuring the peak voltage applied to a radiation source |
US10799278B2 (en) | 2003-03-14 | 2020-10-13 | DePuy Synthes Products, Inc. | Hydraulic device for the injection of bone cement in percutaneous vertebroplasty |
US8992541B2 (en) | 2003-03-14 | 2015-03-31 | DePuy Synthes Products, LLC | Hydraulic device for the injection of bone cement in percutaneous vertebroplasty |
US9186194B2 (en) | 2003-03-14 | 2015-11-17 | DePuy Synthes Products, Inc. | Hydraulic device for the injection of bone cement in percutaneous vertebroplasty |
US8333773B2 (en) | 2003-03-31 | 2012-12-18 | Depuy Spine, Inc. | Remotely-activated vertebroplasty injection device |
US8066713B2 (en) * | 2003-03-31 | 2011-11-29 | Depuy Spine, Inc. | Remotely-activated vertebroplasty injection device |
US10485597B2 (en) | 2003-03-31 | 2019-11-26 | DePuy Synthes Products, Inc. | Remotely-activated vertebroplasty injection device |
US9839460B2 (en) | 2003-03-31 | 2017-12-12 | DePuy Synthes Products, Inc. | Remotely-activated vertebroplasty injection device |
US8361078B2 (en) | 2003-06-17 | 2013-01-29 | Depuy Spine, Inc. | Methods, materials and apparatus for treating bone and other tissue |
US8956368B2 (en) | 2003-06-17 | 2015-02-17 | DePuy Synthes Products, LLC | Methods, materials and apparatus for treating bone and other tissue |
US9504508B2 (en) | 2003-06-17 | 2016-11-29 | DePuy Synthes Products, Inc. | Methods, materials and apparatus for treating bone and other tissue |
US10039585B2 (en) | 2003-06-17 | 2018-08-07 | DePuy Synthes Products, Inc. | Methods, materials and apparatus for treating bone and other tissue |
US8540722B2 (en) | 2003-06-17 | 2013-09-24 | DePuy Synthes Products, LLC | Methods, materials and apparatus for treating bone and other tissue |
US10111697B2 (en) | 2003-09-26 | 2018-10-30 | DePuy Synthes Products, Inc. | Device for delivering viscous material |
US9750840B2 (en) | 2004-03-21 | 2017-09-05 | DePuy Synthes Products, Inc. | Methods, materials and apparatus for treating bone and other tissue |
US8415407B2 (en) | 2004-03-21 | 2013-04-09 | Depuy Spine, Inc. | Methods, materials, and apparatus for treating bone and other tissue |
US8809418B2 (en) | 2004-03-21 | 2014-08-19 | DePuy Synthes Products, LLC | Methods, materials and apparatus for treating bone and other tissue |
US9381024B2 (en) | 2005-07-31 | 2016-07-05 | DePuy Synthes Products, Inc. | Marked tools |
US9918767B2 (en) | 2005-08-01 | 2018-03-20 | DePuy Synthes Products, Inc. | Temperature control system |
US9259696B2 (en) | 2005-11-22 | 2016-02-16 | DePuy Synthes Products, Inc. | Mixing apparatus having central and planetary mixing elements |
US10631906B2 (en) | 2005-11-22 | 2020-04-28 | DePuy Synthes Products, Inc. | Apparatus for transferring a viscous material |
US8360629B2 (en) | 2005-11-22 | 2013-01-29 | Depuy Spine, Inc. | Mixing apparatus having central and planetary mixing elements |
US9642932B2 (en) | 2006-09-14 | 2017-05-09 | DePuy Synthes Products, Inc. | Bone cement and methods of use thereof |
US10272174B2 (en) | 2006-09-14 | 2019-04-30 | DePuy Synthes Products, Inc. | Bone cement and methods of use thereof |
US8950929B2 (en) | 2006-10-19 | 2015-02-10 | DePuy Synthes Products, LLC | Fluid delivery system |
US10494158B2 (en) | 2006-10-19 | 2019-12-03 | DePuy Synthes Products, Inc. | Fluid delivery system |
CN106483554A (en) * | 2016-10-28 | 2017-03-08 | 中国计量科学研究院 | Detecting system |
CN106483554B (en) * | 2016-10-28 | 2018-10-19 | 中国计量科学研究院 | Detecting system |
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AS | Assignment |
Owner name: CITIBANK, N.A.,NEW YORK Free format text: SECURITY INTEREST;ASSIGNOR:VICTOREEN, INC., AN OH. CORP.;REEL/FRAME:004599/0913 Effective date: 19860611 Owner name: CITIBANK, N.A., 641 LEXINGTON AVENUE, NEW YORK, NE Free format text: SECURITY INTEREST;ASSIGNOR:VICTOREEN, INC., AN OH. CORP.;REEL/FRAME:004599/0913 Effective date: 19860611 |
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Owner name: VICTOREEN, INC. Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:CITIBANK, N.A., AS AGENT;REEL/FRAME:004988/0618 Effective date: 19881003 |
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Owner name: SHELLER-GLOBE CORPORATION, A CORP. OF DE Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:CITIBANK, NA AS AGENT;REEL/FRAME:005110/0871 Effective date: 19881209 |