EP0283688B1 - X-ray emitter - Google Patents

X-ray emitter Download PDF

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Publication number
EP0283688B1
EP0283688B1 EP88101814A EP88101814A EP0283688B1 EP 0283688 B1 EP0283688 B1 EP 0283688B1 EP 88101814 A EP88101814 A EP 88101814A EP 88101814 A EP88101814 A EP 88101814A EP 0283688 B1 EP0283688 B1 EP 0283688B1
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EP
European Patent Office
Prior art keywords
housing
liquid pressure
ray source
ray
protective device
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP88101814A
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German (de)
French (fr)
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EP0283688A1 (en
Inventor
Günther Appelt
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Siemens AG
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Siemens AG
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/02—Constructional details
    • H05G1/04—Mounting the X-ray tube within a closed housing
    • 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
    • H05G1/54—Protecting or lifetime prediction

Definitions

  • the invention relates to an X-ray emitter which has a housing filled with an electrically insulating liquid and provided with a radiation passage window and an X-ray tube arranged therein, and a protective device which prevents the operation of the X-ray emitter when the liquid pressure in the housing exceeds a limit value.
  • the safety device is provided in order to keep the pressure rise inside the housing that occurs as a result of the heat loss emitted by the X-ray tube during operation into the interior of the housing within acceptable limits.
  • the protective device which is provided per se for safety reasons, can in turn trigger dangers during medical examinations, namely if the protective device responds during the examination of a patient and unexpectedly puts the x-ray emitter out of operation. In the case of catheterizations, life-threatening situations for the patient could occur.
  • GB-A-556 434 describes an X-ray emitter of the type mentioned in the introduction, in which an optical signal precedes a response of the protective device; However, since it is unclear in each case what time is left from the appearance of the optical signal until the protective device responds, the operating personnel are not able to readily decide whether an examination that has started can still be completed or should be terminated for safety reasons.
  • the invention has for its object to design an X-ray tube of the type mentioned so that hazards Patients are excluded from responding to the protective device and the operating personnel is also able to decide at any time whether an examination that has already started can be completed before the protective device is activated.
  • an X-ray emitter which has a housing filled with an electrically insulating liquid and provided with a radiation passage window and an X-ray tube arranged therein, as well as a protective device and a warning device which prevents the operation of the X-ray emitter when the liquid pressure in the housing exceeds a limit value with a pressure sensor which continuously emits a signal corresponding to the instantaneous value of the liquid pressure in the housing, which warning device emits a warning signal when the threshold value of the liquid pressure is below the limit value for the protective device, and means for determining and displaying those remaining until the limit value of the liquid pressure is reached Has time.
  • the threshold value is dimensioned such that the warning signal is emitted for a sufficient period of time, e.g. 30 minutes before the expected response of the protective device takes place, so that the operating personnel or the examining doctor can assess whether an started examination can be completed in the remaining period or should be terminated for safety reasons. Danger to the patient from an unexpected response of the protective device is therefore excluded.
  • the operating personnel is constantly provided with information about the operating time of the x-ray emitter remaining until the protective device responds.
  • the warning device has a pressure sensor for measuring the threshold value of the liquid pressure. Under certain circumstances this can be a pressure sensor, which is also part of the protective device and is used to measure the limit value of the liquid pressure.
  • the threshold value can be set. It is therefore possible to adapt the period of time between the issue of the warning signal and the response of the protective device to the respective needs.
  • Such a setting of the threshold value is particularly easy to implement if the pressure sensor continuously emits a signal corresponding to the instantaneous value of the pressure and the warning device has means for comparing the signal corresponding to the instantaneous fluid pressure with a desired value corresponding to the threshold value of the fluid pressure, since in this If only the setpoint has to be changed to change the threshold value.
  • the pressure sensor can be directly exposed to the liquid pressure in the housing or, if the housing of the x-ray emitter has a flexible wall section to compensate for temperature-related changes in volume of the coolant, can be actuated indirectly by the flexible wall section, which can be formed by a membrane.
  • the figure shows an X-ray emitter according to the invention, which has a housing 1 filled with an electrically insulating liquid, for example insulating oil, in which an X-ray tube 2 is arranged.
  • an X-ray tube 2 is arranged.
  • This is designed as a rotating anode X-ray tube, which contains an anode plate 3, a cathode 4 and a motor for driving the rotating anode, which has a rotor 5 and a stator 7 arranged outside the glass body of the X-ray tube 2 on an insulator 6.
  • the housing 1 has a radiation passage window 8 for the X-rays emanating from the anode plate 3.
  • a transverse wall 9 on which there is provided a resilient membrane 10, which closes the interior of the housing 1 in a liquid-tight manner, and which serves to absorb temperature-related volume fluctuations of the liquid in the interior of the housing 1.
  • the supply voltages required to operate the X-ray tube namely the cathode heating voltage, the high voltage and the voltage required to drive the rotating anode, are emitted by a generator device 11, with only a single line 12 between the generator device 11 and the for the sake of clarity in the figure X-ray tube 2 is shown.
  • the generator device 11 is connected to a data processing device 33, via whose keyboard 39 the operating data of the X-ray tube 2 can be set and the X-ray emitter can be put into operation.
  • the X-ray emitter In order to keep the rise in the liquid pressure in the housing 1 due to the heat loss of the liquid in the housing 1 due to the heat loss emitted by the X-ray tube 2 in operation below the limit value to be complied with for safety reasons, the X-ray emitter has a protective device which prevents it from operating the liquid pressure in the housing 1 exceeds the limit value.
  • the protective device comprises a pressure sensor 32, which is attached to the housing 1 in such a way that it is directly exposed to the liquid pressure inside the housing 1, a contactor 14 for connecting the X-ray tube 2 to the generator device 11, the contacts 14a, of which only one is shown for the sake of clarity, and has an excitation winding 14b, and a voltage source 42 to which the excitation winding 14b of the contactor 14 can be connected by means of a switching stage 43.
  • the data processing device 33 is part of the protective device.
  • the data processing device 33 comprises one Multiplexer 34, an analog / digital converter 35, a computing device 36, a memory 37, an output unit 38 and a keyboard 39.
  • the keyboard 39 connected to the computing device 36, it is possible to enter the limit value of the liquid pressure in the housing 1. This is then stored in the memory 37 by the computing device 36 and is available there.
  • the operating data for the X-ray emitter can be selected using the keyboard 39, the computing device 36 acting on the generator device 11 via the output unit 38 and causing the latter to provide the corresponding voltages for the X-ray tube 2.
  • the voltages actually emitted by the generator device 11 are fed to a multiplexer 34, to which the signal emitted by the pressure sensor 32, which continuously emits a signal corresponding to the instantaneous value of the liquid pressure in the housing 1, is also fed.
  • the multiplexer 34 From the multiplexer 34, they arrive at the analog / digital converter 35 and from there to the computing device 36. This constantly compares the liquid pressure currently prevailing in the interior of the housing 1 with the value for the limit value of the liquid pressure stored in the memory 37. As long as the liquid pressure in the housing 1 is below the limit value, the contact 14a of the contactor is closed and the X-ray tube 2 is thus connected to the generator circuit 11. It is then operated with the operating data set via the keyboard 39.
  • the computing device 36 acts via the output unit 38 on the switching stage 43 in such a way that the excitation coil 14b of the contactor 14 is disconnected from the voltage source 42, with the result that the contact 14a of the contactor opens and the X-ray tube 2 is separated from the generator device 11, so that the operation of the X-ray emitter is prevented.
  • the x-ray emitter has a warning device which emits a warning signal when the threshold value of the liquid pressure in the housing 1 is below the limit value which is decisive for the protective device.
  • the warning device has a warning lamp 17, an acoustic signal transmitter 18, switching stages 40 and 41 and a time display 44.
  • the data processing device 33 is also part of the warning device.
  • the threshold value of the liquid pressure in the housing 1 which is relevant for the response of the warning device can likewise be entered into the memory 37 of the computing device 36 by means of the keyboard 39. If the liquid pressure in the housing 1 exceeds the threshold value, the computing device 36 acts via the output unit 38 on the switching stages 40 and 41 in such a way that the warning lamp 17 and the acoustic signal generator 18 are connected to the voltage source 42.
  • the threshold value at which the warning device responds is dimensioned, depending on the area of use of the x-ray emitter, in such a way that the warning signal is emitted at a point in time which is sufficiently long before the protective device responds in order to enable the operating personnel to decide whether an intended examination is to be carried out can still be started, or an examination that is already being carried out can still be ended or has to be stopped for safety reasons.
  • the computing device 36 continuously calculates from the instantaneous value of the liquid pressure and the values supplied to it via the multiplexer 34 and the analog / digital converter 35 for the operating data of the X-ray tube 2 and the stored limit value of the liquid pressure and shows the period of time until it is reached this via the output device 38 on a time display 44.
  • the time remaining in the currently set operating data of the X-ray tube 2 until the protective device responds appears on the time display 44. If the operating data of the x-ray tube 2 are changed in a way that affects the heat loss emitted by the x-ray tube 2 per unit of time, this is immediately taken into account in the calculation of the time remaining until the protective device responds, so that changes in the operating data of the x-ray tube also occur 2 correct information can always be found on the time display 44 during the examination.

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • X-Ray Techniques (AREA)
  • Measuring Fluid Pressure (AREA)

Description

Die Erfindung betrifft einen Röntgenstrahler, welcher ein mit einer elektrisch isolierenden Flüssigkeit gefülltes, mit einem Strahlendurchtrittsfenster versehenes Gehäuse und eine in diesem angeordnete Röntgenröhre sowie eine den Betrieb des Röntgenstrahlers bei einem einen Grenzwert überschreitenden Flüssigkeitsdruck im Gehäuse unterbindende Schutzeinrichtung aufweist.The invention relates to an X-ray emitter which has a housing filled with an electrically insulating liquid and provided with a radiation passage window and an X-ray tube arranged therein, and a protective device which prevents the operation of the X-ray emitter when the liquid pressure in the housing exceeds a limit value.

Bei derartigen bekannten Röntgenstrahlern ist die Sicherheitsvorrichtung vorgesehen, um den infolge der von der Röntgenröhre im Betrieb an die Flüssigkeit abgegebene Verlustwärme auftretenden Druckanstieg im Innern des Gehäuses innerhalb zulässiger Grenzen zu halten. Die an sich aus Sicherheitsgründen vorgesehene Schutzeinrichtung kann aber bei medizinischen Untersuchungen ihrerseits Gefahren auslösen, und zwar wenn während der Untersuchung eines Patienten die Schutzeinrichtung anspricht und den Röntgenstrahler unerwarteterweise außer Betrieb setzt. Dabei könnten im Falle von Katheterisierungen durchaus lebensbedrohliche Situationen für den Patienten auftreten.In such known X-ray emitters, the safety device is provided in order to keep the pressure rise inside the housing that occurs as a result of the heat loss emitted by the X-ray tube during operation into the interior of the housing within acceptable limits. However, the protective device, which is provided per se for safety reasons, can in turn trigger dangers during medical examinations, namely if the protective device responds during the examination of a patient and unexpectedly puts the x-ray emitter out of operation. In the case of catheterizations, life-threatening situations for the patient could occur.

In der GB-A-556 434 ist zwar ein Röntgenstrahler der eingangs genannten Art beschrieben, bei dem einem Ansprechen der Schutzeinrichtung ein optisches Signal vorangeht; da jedoch jeweils unklar ist, welche Zeit vom Auftreten des optischen Signals bis zum Ansprechen der Schutzeinrichtung noch verbleibt, ist das Bedienpersonal nicht ohne weiteres in der Lage, zu entscheiden, ob eine begonnene Untersuchung noch abgeschlossen werden kann oder sicherheitshalber abzubrechen ist.GB-A-556 434 describes an X-ray emitter of the type mentioned in the introduction, in which an optical signal precedes a response of the protective device; However, since it is unclear in each case what time is left from the appearance of the optical signal until the protective device responds, the operating personnel are not able to readily decide whether an examination that has started can still be completed or should be terminated for safety reasons.

Der Erfindung liegt die Aufgabe zugrunde, einen Röntgenstrahler der eingangs genannten Art so auszubilden, daß Gefährdungen des Patienten durch das Ansprechen der Schutzeinrichtung ausgeschlossen sind und außerdem das Bedienpersonal jederzeit in der Lage ist, zu entscheiden, ob eine bereits begonnene Untersuchung noch vor dem Ansprechen der Schutzeinrichtung abgeschlossen werden kann.The invention has for its object to design an X-ray tube of the type mentioned so that hazards Patients are excluded from responding to the protective device and the operating personnel is also able to decide at any time whether an examination that has already started can be completed before the protective device is activated.

Nach der Erfindung wird diese Aufgabe gelöst durch einen Röntgenstrahler, welcher ein mit einer elektrisch isolierenden Flüssigkeit gefülltes, mit einem Strahlendurchtrittsfenster versehenes Gehäuse und eine in diesem angeordnete Röntgenröhre sowie eine den Betrieb des Röntgenstrahlers bei einem einen Grenzwert überschreitenden Flüssigkeitsdruck im Gehäuse unterbindende Schutzeinrichtung und eine Warneinrichtung mit einem kontinuierlich ein dem momentanen Wert des Flüssigkeitsdruckes im Gehäuse entsprechendes Signal abgebenden Druckfühler aufweist, welche Warneinrichtung bei einem unterhalb des für die Schutzeinrichtung maßgebenden Grenzwertes liegenden Schwellwert des Flüssigkeitsdruckes ein Warnsignal abgibt und Mittel zur Bestimmung und Anzeige der bis zum Erreichen des Grenzwertes des Flüssigkeitsdruckes verbleibenden Zeit aufweist. Dabei ist der Schwellwert so bemessen, daß die Abgabe des Warnsignales einen ausreichenden Zeitraum, z.B. 30 Minuten, vor dem zu erwartenden Ansprechen der Schutzeinrichtung erfolgt, so daß das Bedienpersonal bzw. der untersuchende Arzt beurteilen kann, ob eine begonnene Untersuchung in dem verbleibenden Zeitraum abgeschlossen werden kann oder sicherheitshalber abzubrechen ist. Gefährdungen des Patienten durch ein unerwartetes Ansprechen der Schutzeinrichtung sind somit ausgeschlossen. Außerdem steht dem Bedienpersonal durch die Anzeige der bis zum Erreichen des Grenzwertes verbleibenden Zeit ständig eine Information über die bis zum Ansprechen der Schutzeinrichtung verbleibenden Betriebszeit des Röntgenstrahlers zur Verfügung.According to the invention, this object is achieved by an X-ray emitter which has a housing filled with an electrically insulating liquid and provided with a radiation passage window and an X-ray tube arranged therein, as well as a protective device and a warning device which prevents the operation of the X-ray emitter when the liquid pressure in the housing exceeds a limit value with a pressure sensor which continuously emits a signal corresponding to the instantaneous value of the liquid pressure in the housing, which warning device emits a warning signal when the threshold value of the liquid pressure is below the limit value for the protective device, and means for determining and displaying those remaining until the limit value of the liquid pressure is reached Has time. The threshold value is dimensioned such that the warning signal is emitted for a sufficient period of time, e.g. 30 minutes before the expected response of the protective device takes place, so that the operating personnel or the examining doctor can assess whether an started examination can be completed in the remaining period or should be terminated for safety reasons. Danger to the patient from an unexpected response of the protective device is therefore excluded. In addition, by displaying the time remaining until the limit value is reached, the operating personnel is constantly provided with information about the operating time of the x-ray emitter remaining until the protective device responds.

Zur Messung des Schwellwertes des Flüssigkeitsdruckes weist die Warneinrichtung nach einer Variante der Erfindung einen Druckfühler auf. Bei diesem kann es sich unter Umständen um einen Druckfühler handeln, der zugleich Bestandteil der Schutzeinrichtung ist und dort zur Messung des Grenzwertes des Flüssigkeitsdruckes dient.According to a variant of the invention, the warning device has a pressure sensor for measuring the threshold value of the liquid pressure. Under certain circumstances this can be a pressure sensor, which is also part of the protective device and is used to measure the limit value of the liquid pressure.

Da je nach Einsatzgebiet des Röntgenstrahlers die Zeitdauer, für die dieser während einer Untersuchung in Betrieb sein muß, stark schwanken kann, ist nach einer Ausführungsform der Erfindung vorgesehen, daß der Schwellwert einstellbar ist. Es ist somit möglich, den zwischen der Abgabe des Warnsignales und dem Ansprechen der Schutzeinrichtung liegenden Zeitraum den jeweiligen Bedürfnissen anzupassen. Eine solche Einstellung des Schwellwertes ist dann besonders einfach zu realisieren, wenn der Druckfühler kontinuierlich ein dem momentanen Wert des Druckes entsprechendes Signal abgibt und die Warneinrichtung Mittel zum Vergleichen des dem momentanen Flüssigkeitsdruck entsprechenden Signales mit einem dem Schwellwert des Flüssigkeitsdruckes entsprechenden Sollwert aufweist, da in diesem Fall zum Verändern des Schwellwertes lediglich der Sollwert verändert werden muß.Since, depending on the field of use of the x-ray emitter, the length of time for which the x-ray emitter must be in operation during an examination can vary greatly, it is provided according to one embodiment of the invention that the threshold value can be set. It is therefore possible to adapt the period of time between the issue of the warning signal and the response of the protective device to the respective needs. Such a setting of the threshold value is particularly easy to implement if the pressure sensor continuously emits a signal corresponding to the instantaneous value of the pressure and the warning device has means for comparing the signal corresponding to the instantaneous fluid pressure with a desired value corresponding to the threshold value of the fluid pressure, since in this If only the setpoint has to be changed to change the threshold value.

Nach Varianten der Erfindung kann der Druckfühler dem Flüssigkeitsdruck im Gehäuse unmittelbar ausgesetzt oder, sofern das Gehäuse des Röntgenstrahlers einen nachgiebigen Wandabschnitt zum Ausgleich temperaturbedingter Volumenänderungen des Kühlmittels aufweist, durch den nachgiebigen Wandabschnitt, der durch eine Membran gebildet sein kann, mittelbar betätigt sein.According to variants of the invention, the pressure sensor can be directly exposed to the liquid pressure in the housing or, if the housing of the x-ray emitter has a flexible wall section to compensate for temperature-related changes in volume of the coolant, can be actuated indirectly by the flexible wall section, which can be formed by a membrane.

In der beigefügten Zeichnung ist ein Ausführungsbeispiel der Erfindung schematisch dargestellt.In the accompanying drawing, an embodiment of the invention is shown schematically.

Die Figur zeigt einen erfindungsgemäßen Röntgenstrahler, der ein mit einer elektrisch isolierenden Flüssigkeit, z.B. Isolieröl, gefülltes Gehäuse 1 aufweist, in dem eine Röntgenröhre 2 angeordnet ist. Diese ist als Drehanoden-Röntgenröhre ausgebildet, die einen Anodenteller 3, eine Kathode 4 und einen Motor zum Antrieb der Drehanode enthält, der einen Rotor 5 und einen außerhalb des Glaskörpers der Röntgenröhre 2 auf einem Isolator 6 angeordneten Stator 7 aufweist. Das Gehäuse 1 besitzt ein Strahlendurchtrittsfenster 8 für die vom Anodenteller 3 ausgehende Röntgenstrahlung. Innerhalb des Gehäuses 1 ist eine Querwand 9 vorgesehen, an der eine den Innenraum des GeGehäuses 1 flüssigkeitsdicht verschließende, nach außen gewölbte nachgiebige Membran 10 vorgesehen ist, die dazu dient, temperaturbedingte Volumenschwankungen der Flüssigkeit im Inneren des Gehäuses 1 aufzunehmen. Die zum Betrieb der Röntgenröhre erforderlichen Versorgungsspannungen, nämlich die Kathoden-Heizspannung, die Hochspannung und die zum Antrieb der Drehanode erforderliche Spannung, gibt eine Generatoreinrichtung 11 ab, wobei in der Figur aus Gründen der Übersichtlichkeit nur eine einzige Leitung 12 zwischen der Generatoreinrichtung 11 und der Röntgenröhre 2 dargestellt ist. Die Generatoreinrichtung 11 ist mit einer Datenverarbeitungseinrichtung 33 verbunden, über deren Tastatur 39 die Betriebsdaten der Röntgenröhre 2 eingestellt werden können und der Röntgenstrahler in Betrieb gesetzt werden kann.The figure shows an X-ray emitter according to the invention, which has a housing 1 filled with an electrically insulating liquid, for example insulating oil, in which an X-ray tube 2 is arranged. This is designed as a rotating anode X-ray tube, which contains an anode plate 3, a cathode 4 and a motor for driving the rotating anode, which has a rotor 5 and a stator 7 arranged outside the glass body of the X-ray tube 2 on an insulator 6. The housing 1 has a radiation passage window 8 for the X-rays emanating from the anode plate 3. Provided within the housing 1 is a transverse wall 9, on which there is provided a resilient membrane 10, which closes the interior of the housing 1 in a liquid-tight manner, and which serves to absorb temperature-related volume fluctuations of the liquid in the interior of the housing 1. The supply voltages required to operate the X-ray tube, namely the cathode heating voltage, the high voltage and the voltage required to drive the rotating anode, are emitted by a generator device 11, with only a single line 12 between the generator device 11 and the for the sake of clarity in the figure X-ray tube 2 is shown. The generator device 11 is connected to a data processing device 33, via whose keyboard 39 the operating data of the X-ray tube 2 can be set and the X-ray emitter can be put into operation.

Um den infolge der Erwärmung der in dem Gehäuse 1 befindlichen Flüssigkeit durch die von der Röntgenröhre 2 im Betrieb abgegebenen Verlustwärme auftretenden Anstieg des Flüssigkeitsdrukkes im Gehäuse 1 unterhalb eines aus Sicherheitsgründen einzuhaltenden Grenzwertes zu halten, weist der Röntgenstrahler eine Schutzeinrichtung auf, die dessen Betrieb bei einem den Grenzwert überschreitenden Flüssigkeitsdruck im Gehäuse 1 unterbindet. Im einzelnen umfaßt die Schutzeinrichtung einen Drucksensior 32, der derart an dem Gehäuse 1 angebracht ist, daß er dem Flüssigkeitsdruck im Inneren des Gehäuses 1 unmittelbar ausgesetzt ist, ein Schütz 14 zur Anschaltung der Röntgenröhre 2 an die Generatoreinrichtung 11, das Kontakte 14a, von denen der Übersichtlichkeit halber nur einer dargestellt ist, und eine Erregerwicklung 14b aufweist, und eine Spannungsquelle 42, an die die Erregerwicklung 14b des Schützes 14 mittels einer Schaltstufe 43 anschaltbar ist. Außerdem ist die Datenverarbeitungseinrichtung 33 Bestandteil der Schutzeinrichtung.In order to keep the rise in the liquid pressure in the housing 1 due to the heat loss of the liquid in the housing 1 due to the heat loss emitted by the X-ray tube 2 in operation below the limit value to be complied with for safety reasons, the X-ray emitter has a protective device which prevents it from operating the liquid pressure in the housing 1 exceeds the limit value. In particular, the protective device comprises a pressure sensor 32, which is attached to the housing 1 in such a way that it is directly exposed to the liquid pressure inside the housing 1, a contactor 14 for connecting the X-ray tube 2 to the generator device 11, the contacts 14a, of which only one is shown for the sake of clarity, and has an excitation winding 14b, and a voltage source 42 to which the excitation winding 14b of the contactor 14 can be connected by means of a switching stage 43. In addition, the data processing device 33 is part of the protective device.

Im einzelnen umfaßt die Datenverarbeitungseinrichtung 33 einen Multiplexer 34, einen Analog/Digital-Wandler 35, einen Recheneinrichtung 36, einen Speicher 37, eine Ausgabeeinheit 38 und eine Tastatur 39.In particular, the data processing device 33 comprises one Multiplexer 34, an analog / digital converter 35, a computing device 36, a memory 37, an output unit 38 and a keyboard 39.

Mittels der mit der Recheneinrichtung 36 verbundenen Tastatur 39 besteht die Möglichkeit, den Grenzwert des Flüssigkeitsdruckes im Gehäuse 1 einzugeben. Dieser wird dann von der Recheneinrichtung 36 in dem Speicher 37 abgelegt und steht dort zur Verfügung. Außerdem können wie erwähnt mittels der Tastatur 39 die Betriebsdaten für den Röntgenstrahler gewählt werden, wobei die Recheneinrichtung 36 über die Ausgabeeinheit 38 auf die Generatoreinrichtung 11 einwirkt und diese veranlaßt, die entsprechenden Spannungen für die Röntgenröhre 2 bereitzustellen. Die tatsächlich von der Generatoreinrichtung 11 abgegebenen Spannungen werden einem Multiplexer 34 zugeführt, dem außerdem das von dem Druckfühler 32 abgegebene Signal, dieser gibt kontinuierlich ein dem momentanen Wert des Flüssigkeitsdruckes im Gehäuse 1 entsprechendes Signal ab, zugeführt wird. Von dem Multiplexer 34 gelangen diese zu dem Analog/Digital-Wandler 35 und von dort zu der Recheneinrichtung 36. Diese vergleicht ständig den momentan im Inneren des Gehäuses 1 herrschenden Flüssigkeitsdruck mit den in dem Speicher 37 abgespeicherten Wert für den Grenzwert des Flüssigkeitsdruckes. Solange der Flüssigkeitsdruck im Gehäuse 1 unterhalb des Grenzwertes liegt, ist der Kontakt 14a des Schützes geschlossen und die Röntgenröhre 2 somit an die Generatorschaltung 11 angeschaltet. Sie wird dann mit den über die Tastatur 39 eingestellten Betriebsdaten betrieben. Sobald der Flüssigkeitsdruck im Gehäuse 1 den Grenzwert übersteigt, wirkt die Recheneinrichtung 36 über die Ausgabeeinheit 38 auf die Schaltstufe 43 derart ein, daß die Erregerspule 14b des Schützes 14 von der Spannungsquelle 42 getrennt wird, was zur Folge hat, daß der Kontakt 14a des Schützes öffnet und die Röntgenröhre 2 von der Generatoreinrichtung 11 getrennt ist, so daß der Betrieb des Röntgenstrahlers unterbunden ist.Using the keyboard 39 connected to the computing device 36, it is possible to enter the limit value of the liquid pressure in the housing 1. This is then stored in the memory 37 by the computing device 36 and is available there. In addition, as mentioned, the operating data for the X-ray emitter can be selected using the keyboard 39, the computing device 36 acting on the generator device 11 via the output unit 38 and causing the latter to provide the corresponding voltages for the X-ray tube 2. The voltages actually emitted by the generator device 11 are fed to a multiplexer 34, to which the signal emitted by the pressure sensor 32, which continuously emits a signal corresponding to the instantaneous value of the liquid pressure in the housing 1, is also fed. From the multiplexer 34, they arrive at the analog / digital converter 35 and from there to the computing device 36. This constantly compares the liquid pressure currently prevailing in the interior of the housing 1 with the value for the limit value of the liquid pressure stored in the memory 37. As long as the liquid pressure in the housing 1 is below the limit value, the contact 14a of the contactor is closed and the X-ray tube 2 is thus connected to the generator circuit 11. It is then operated with the operating data set via the keyboard 39. As soon as the liquid pressure in the housing 1 exceeds the limit value, the computing device 36 acts via the output unit 38 on the switching stage 43 in such a way that the excitation coil 14b of the contactor 14 is disconnected from the voltage source 42, with the result that the contact 14a of the contactor opens and the X-ray tube 2 is separated from the generator device 11, so that the operation of the X-ray emitter is prevented.

Um auf das bevorstehende Ansprechen der Schutzeinrichtung, d.h. die Unterbrechung des Betriebes des Röntgenstrahlers, aufmerksam zu machen, weist der erfindungsgemäße Röntgenstrahler eine Warneinrichtung auf, welche bei einem unterhalb des für die Schutzeinrichtung maßgebenden Grenzwertes liegenden Schwellwertes des Flüssigkeitsdruckes im Gehäuse 1 ein Warnsignal abgibt. Die Warneinrichtung weist neben dem Drucksensor 32 und der Spannungsquelle 42, die auch Bestandteile der Schutzeinrichtung sind, eine Warnlampe 17, einen akustischen Signalgeber 18, Schaltstufen 40 und 41 sowie ein Zeitdisplay 44 auf. Die Datenverarbeitungseinrichtung 33 ist ebenfalls Bestandteil der Warneinrichtung.To respond to the upcoming response of the protective device, ie to draw attention to the interruption in the operation of the x-ray emitter, the x-ray emitter according to the invention has a warning device which emits a warning signal when the threshold value of the liquid pressure in the housing 1 is below the limit value which is decisive for the protective device. In addition to the pressure sensor 32 and the voltage source 42, which are also components of the protective device, the warning device has a warning lamp 17, an acoustic signal transmitter 18, switching stages 40 and 41 and a time display 44. The data processing device 33 is also part of the warning device.

Der für das Ansprechen der Warneinrichtung maßgebliche Schwellwert des Flüssigkeitsdruckes im Gehäuse 1 kann ebenfalls mittels der Tastatur 39 in den Speicher 37 der Recheneinrichtung 36 eingegeben werden. Übersteigt der Flüssigkeitsdruck im Gehäuse 1 den Schwellwert, wirkt die Recheneinrichtung 36 über die Ausgabeeinheit 38 auf die Schaltstufen 40 und 41 derart ein, daß die Warnlampe 17 und der akustische Signalgeber 18 mit der Spannungsquelle 42 verbunden sind.The threshold value of the liquid pressure in the housing 1 which is relevant for the response of the warning device can likewise be entered into the memory 37 of the computing device 36 by means of the keyboard 39. If the liquid pressure in the housing 1 exceeds the threshold value, the computing device 36 acts via the output unit 38 on the switching stages 40 and 41 in such a way that the warning lamp 17 and the acoustic signal generator 18 are connected to the voltage source 42.

Der Schwellwert, bei dem die Warneinrichtung anspricht, wird je nach Einsatzgebiet des Röntgenstrahlers so bemessen, daß das Warnsignal zu einem Zeitpunkt abgegeben wird, der ausreichend lange vor dem Ansprechen der Schutzeinrichtung liegt, um den Bedienpersonal eine Entscheidung darüber zu ermöglichen, ob eine beabsichtigte Untersuchung noch begonnen werden bzw. eine bereits in der Durchführung begriffene Untersuchung noch beendet werden kann oder aus Sicherheitsgründen abzubrechen ist.The threshold value at which the warning device responds is dimensioned, depending on the area of use of the x-ray emitter, in such a way that the warning signal is emitted at a point in time which is sufficiently long before the protective device responds in order to enable the operating personnel to decide whether an intended examination is to be carried out can still be started, or an examination that is already being carried out can still be ended or has to be stopped for safety reasons.

Außerdem berechnet die Recheneinrichtung 36 aus dem momentanen Wert des Flüssigkeitsdruckes und den ihr über den Multiplexer 34 und den Analog/Digital-Wandler 35 zugeführten Werten für die Betriebsdaten der Röntgenröhre 2 sowie dem gespeicherten Grenzwert des Flüssigkeitsdruckes ständig den bis zu dessen Erreichen verbleibenden Zeitraum und zeigt diesen über die Ausgabeeinrichtung 38 auf einem Zeitdisplay 44 an.In addition, the computing device 36 continuously calculates from the instantaneous value of the liquid pressure and the values supplied to it via the multiplexer 34 and the analog / digital converter 35 for the operating data of the X-ray tube 2 and the stored limit value of the liquid pressure and shows the period of time until it is reached this via the output device 38 on a time display 44.

Bei der Ermittlung der bis zum Ansprechen der Schutzeinrichtung verbleibenden Zeit wird von der Erkenntnis Gebrauch gemacht, daß dem momentan im Gehäuse 1 herrschenden Flüssigkeitsdruck und dem Grenzwert des Flüssigkeitsdruckes bestimmte Temperaturen zugeordnet sind, wobei der Differenz dieser Temperaturen eine bestimmte Wärmemenge zugeordnet werden kann, die erforderlich ist, um das in dem Gehäuse 1 befindliche Isolieröl von der dem momentanen Flüssigkeitsdruck entsprechenden Temperatur auf die dem Grenzwert des Flüssigkeitsdruckes entsprechende Temperatur aufzuheizen. Da außerdem aus den Betriebsdaten der Röntgenröhre 2 die pro Zeiteinheit anfallende Verlustwärme errechnet werden kann, besteht somit die Möglichkeit, den bis zum Erreichen des Grenzwertes des Flüssigkeitsdruckes, also bis zum Ansprechen der Schutzschaltung verbleibenden Zeitraum zu berechnen. Die Verlängerung dieses Zeitraumes infolge der von dem Röntgenstrahler an die Umgebung abgegebene Wärmemenge kann durch einen einfachen Iterationsvorgang ebenfalls berücksichtigt werden.When determining the time remaining until the protective device responds, use is made of the knowledge that certain temperatures are assigned to the liquid pressure currently prevailing in the housing 1 and the limit value of the liquid pressure, the difference between these temperatures being able to be assigned a certain amount of heat that is required is to heat the insulating oil located in the housing 1 from the temperature corresponding to the instantaneous liquid pressure to the temperature corresponding to the limit value of the liquid pressure. Since the operating heat of the X-ray tube 2 can also be used to calculate the heat loss per unit of time, it is possible to calculate the time remaining until the limit value of the liquid pressure is reached, that is, until the protective circuit responds. The extension of this period due to the amount of heat given off by the X-ray emitter to the surroundings can also be taken into account by a simple iteration process.

Auf dem Zeitdisplay 44 erscheint somit der bei den momentan eingestellten Betriebsdaten der Röntgenröhre 2 bis zum Ansprechen der Schutzeinrichtung verbleibende Zeitraum. Werden die Betriebsdaten der Röntgenröhre 2 in einer Weise verändert, die sich auf die von der Röntgenröhre 2 pro Zeiteinheit abgegebene Verlustwärme auswirken, wird dies umgehend bei der Berechnung des bis zum Ansprechen der Schutzeinrichtung verbleibenden Zeitraumes berücksichtigt, so daß auch bei Veränderungen der Betriebsdaten der Röntgenröhre 2 während der Untersuchung dem Zeitdisplay 44 stets eine korrekte Information zu entnehmen ist.The time remaining in the currently set operating data of the X-ray tube 2 until the protective device responds appears on the time display 44. If the operating data of the x-ray tube 2 are changed in a way that affects the heat loss emitted by the x-ray tube 2 per unit of time, this is immediately taken into account in the calculation of the time remaining until the protective device responds, so that changes in the operating data of the x-ray tube also occur 2 correct information can always be found on the time display 44 during the examination.

Claims (6)

  1. An X-ray source which has a housing (1) filled with an electrically insulating liquid and provided with a ray passage window (8), and having an x-ray tube (2) arranged in this housing as well as a protective device (14, 32, 33) stopping operation of the X-ray source when the liquid pressure in the housing (1) exceeds a limiting value, and a warning device (17, 18, 32, 33, 44) with a pressure sensor (32) continually delivering a signal corresponding to the momentary value of the liquid pressure in the housing (1), which warning device (17, 18, 32, 33, 44) delivers a warning signal at a threshold value of the liquid pressure lying below the limiting value applicable to the protective device (14,32,33), and comprises means (33, 44) for determining and displaying the time remaining until the limiting value of the liquid pressure is reached.
  2. An X-ray source according to claim 1, characterised in that the threshold value is adjustable.
  3. An X-ray source according to claim 1 or 2, characterised in that the warning device has means (33) for comparing the signal corresponding to the momentary liquid pressure with a desired value corresponding to the threshold value of the liquid pressure.
  4. An X-ray source according to one of claims 1 to 3, characterised in that the pressure sensor (16, 27, 32) is directly exposed to the liquid pressure in the housing (1).
  5. An X-ray source according to one of claims 1 to 3, the housing (1) of which has a flexible wall section (10) for compensating the temperature-dependent volume changes of the cooling agent, characterised in that the pressure sensor is indirectly activated by the flexible wall section (10).
  6. An X-ray source according to claim 5, characterised in that the flexible wall section of the housing (1) is formed by a membrane (10).
EP88101814A 1987-02-20 1988-02-08 X-ray emitter Expired - Lifetime EP0283688B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3705544 1987-02-20
DE3705544 1987-02-20

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EP0283688A1 EP0283688A1 (en) 1988-09-28
EP0283688B1 true EP0283688B1 (en) 1992-11-11

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EP88101814A Expired - Lifetime EP0283688B1 (en) 1987-02-20 1988-02-08 X-ray emitter

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US (1) US4862489A (en)
EP (1) EP0283688B1 (en)
JP (1) JPH0515760Y2 (en)
DE (1) DE3875764D1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2646982B1 (en) * 1989-05-10 1992-02-07 Gen Electric Cgr SECURITY DEVICE FOR RADIOGENIC ASSEMBLY
US5056129A (en) * 1989-09-12 1991-10-08 The United States Of America As Represented By The United States Department Of Energy Apparatus for monitoring X-ray beam alignment
FR2679762B1 (en) * 1991-07-31 1993-11-05 General Electric Cgr Sa SECURITY DEVICE IN A RADIOLOGY APPARATUS.
DE19707726C1 (en) * 1997-02-26 1998-09-24 Siemens Ag X-ray source with safety device
DE19707996A1 (en) * 1997-02-27 1998-09-10 Siemens Ag Warning device for X-ray source
DE10314538A1 (en) * 2003-03-31 2004-10-28 Siemens Ag X-ray tube pressure monitoring method in which the pressure inside the tube is measured, based on measurements of heating and tube currents and their comparison with calibration values, to predict remaining tube service life
DE102015212393B4 (en) 2015-07-02 2021-08-12 Siemens Healthcare Gmbh Container for an X-ray generator with a pressure compensation device and X-ray generator with a container
CN109646029A (en) * 2019-01-15 2019-04-19 麦默真空技术无锡有限公司 A kind of control method and system of CT bulb fault pre-alarming

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FR745783A (en) * 1931-11-13 1933-05-16
DE738296C (en) * 1937-02-28 1943-08-10 Electricitaetsgesellschaft San Device to avoid local overheating in spatially adjustable containers for X-ray tubes filled with an insulating and coolant
GB556434A (en) * 1942-03-31 1943-10-05 Edwin Russell Goldfield X-ray tube safety switch
GB834719A (en) * 1957-11-04 1960-05-11 William Warren Triggs Safety x-ray tube housing
US3746862A (en) * 1970-11-30 1973-07-17 Picker Corp Protective circuit for x-ray tube and method of operation
US3955119A (en) * 1973-01-29 1976-05-04 Varian Associates Apparatus for predicting incipient failure of an X-ray generator tube
JPS5160772U (en) * 1974-11-08 1976-05-13
DE2813860A1 (en) * 1978-03-31 1979-10-04 Philips Patentverwaltung SINGLE-TANK X-RAY GENERATOR
JPS54146587A (en) * 1978-05-09 1979-11-15 Toshiba Corp Monitor device for x-ray generator
US4386320A (en) * 1978-09-15 1983-05-31 Lafrance Robert R X-Ray system signal derivation circuits for heat unit indicators and/or calibration meters

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DE3875764D1 (en) 1992-12-17
JPH0515760Y2 (en) 1993-04-26
JPS63133098U (en) 1988-08-31
US4862489A (en) 1989-08-29
EP0283688A1 (en) 1988-09-28

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