MONITORING OF X-RAY TUBE

Abstract

The invention relates to an optical monitoring system (200) for monitoring an X-ray tube (100), the optical monitoring system (200) comprising: at least one optical sensor (201) configured to detect first signals of a first optical parameter and second signals of a second optical parameter thereby generating measurement data, wherein the first and second optical parameters are selected from the group comprising plasma glow, discharges, micro-discharges, arcs, x-ray fluorescence, line emissions, wherein the first and second optical parameters are different from each other, the optical monitoring system (200) further comprising a computing unit (202) configured to transmit, to a remote system (300) external of optical monitoring system (200) and the X-ray tube (100), said generated measurement data and/or a result of an analysis of measurement data carried out by the computing unit (202). The invention further relates to a unit comprising an X-ray tube (100) and such an optical monitoring system (200), as well as to a method (400) for monitoring an X-ray tube (100).

Claims

1. An optical monitoring system for monitoring an X-ray tube, comprising: at least one optical sensor configured to detect first signals of a first optical parameter and second signals of a second optical parameter thereby generating measurement data, wherein the first optical parameter and the second optical parameters are by-products and/or side-effects of an electron beam and/or emitted X-ray radiation generated by the X-ray tube, wherein the first optical parameter and the second optical parameters are different from each other; and a processor configured to analyze the generated measurement data and to transmit the generated measurement data and/or a result of an analysis of the measurement data, to a remote system external of optical monitoring system and the X-ray tube.

2. The optical monitoring system according to claim 1, wherein the first optical parameter and the second optical parameter are selected from the group consisting of plasma glow, discharges, micro-discharges, arcs, x-ray fluorescence, and line emissions.

3. The optical monitoring system according to claim 1, wherein the first optical parameter and the second optical parameter exclude X-ray radiation, and the first signals and the second signals exclude X-ray radiation signals.

4. The optical monitoring system according to claim 1, wherein an X-ray tube lifetime model comprising at least one predefined pattern for tube status and/or tube aging is stored in the processor, and wherein the processor is configured to use the stored X-ray tube lifetime model for analyzing the detected first signals of the first optical parameter and analyzing the detected second signals of the second optical parameter.

5. The optical monitoring system according to claim 4, wherein the predefined pattern comprises at least one of: one event, one process, one predefined range, and one threshold being indicative of a tube age, a tube wear status, or a tube vacuum status.

6. The optical monitoring system according to claim 1, wherein the optical sensor is configured to detect line emissions from at least one of the chemical elements B, Si, Na, K, Ca, Sr, Mg, O, N, H, W, Re, Rh, Ga, In, Sn, Mo, Ni, Co, Be, Al, and Fe, as first signal.

7. The optical monitoring system according to claim 1, further comprising at least one non-optical sensor configured to detect signals of at least one non-optical parameter.

8. The optical monitoring system according to claim 1, further comprising a power supply.

9. The optical monitoring system according to claim 1, wherein the optical monitoring system is configured to use cell-phone-based communication or another wireless communication to transmit the collected signals and/or the analysis results to the remote system.

10-13. (canceled)

14. A computer-implemented method for monitoring an X-ray tube, the method comprising: detecting first signals of a first optical parameter and second signals of a second optical parameter by at least one optical sensor of an optical monitoring system; generating measurement data based on the detected first signals and the second signals, wherein the first optical parameter and the second optical parameter are different from each other, analyzing the generated measurement data; and transmitting the generated measurement data and/or a result of an analysis of measurement data to a remote system external of the X-ray tube and of the optical monitoring system.

15. The method according to claim 14, wherein collecting the first signals of the first optical parameter and the second signals of the second optical parameter includes time-stamping the signals and saving the signals.

16. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Exemplary embodiments of this disclosure will be described in the following drawings.

[0044] FIG. 1 shows a schematic view of an exemplary embodiment of an X-ray tube and several positions for sensors of an optical monitoring system for monitoring the X-ray tube.

[0045] FIG. 2 shows a schematic illustration of an exemplary embodiment of an optical monitoring system for monitoring an X-ray tube.

[0046] FIG. 3 shows a schematic illustration of another exemplary embodiment of an optical monitoring system for monitoring an X-ray tube.

[0047] FIG. 4 shows a schematic illustration of another exemplary embodiment of an optical monitoring system for monitoring an X-ray tube.

[0048] FIG. 5 shows a flowchart of an exemplary embodiment of a method for monitoring an X-ray tube.

[0049] The figures are merely schematic representations and serve only to illustrate embodiments of the invention. Identical or equivalent elements are in principle provided with the same reference signs.

DETAILED DESCRIPTION OF EMBODIMENTS

[0050] FIG. 1 shows an exemplary embodiment of an X-ray tube 100 in a schematic illustration. The X-ray tube comprises a cathode 101, an anode 102 having an anode rotor 103 and an anode stator 104, a tube envelope 105 forming a vacuum casing, a tube housing 106 forming a shielded casing. The tube envelope 105 encases an evacuated volume 107 forming a vacuum environment for the cathode 101 and the anode 102. The tube housing 106 encases the tube envelope 105 and is filled with an isolating, cooling medium 108. For generating X-ray radiation, the cathode 101 emits electrons in form of an electron beam 109 towards the anode 102, and X-rays 110 are emitted from the anode 102 in the spots where the electron beam 109 hits the anode 102.

[0051] During operation, X-ray tube 100 undergoes wearing processes due to which the X-ray tube 100 eventually fails. For detecting deterioration of the X-ray tube 100, the X-ray tube 100 is monitored by an optical monitoring system 200, which will be described in more detail with regard to FIGS. 2 to 4. In FIG. 1, letters A, B, C, D and E mark positions where sensors of the optical monitoring system 200 can be placed for monitoring the X-ray tube 100, depending on parameters to be monitored by the optical monitoring system 200.

[0052] FIG. 2 shows an exemplary embodiment of the optical monitoring system 200 for monitoring the X-ray tube 100. The optical monitoring system 200 comprises an optical sensor 201 and a computing unit 202. FIG. 3 shows another exemplary embodiment of the optical monitoring system 200 for monitoring an X-ray tube 100. The optical monitoring system 200 comprises the optical sensor 201, the computing unit 202 and additionally comprises a non-optical sensor 203.

[0053] The optical sensor 201 is configured to detect a first signal from a first optical parameter and a second signal from a second optical parameter as measurement data. The optical parameters are selected from the group comprising plasma glow, discharges, micro-discharges, arcs, x-ray fluorescence, and different line emissions. The optical parameters often are by-products and/or side-effects from the emitted X-ray radiation 110 and/or excitation by the electron beam 109. The optical sensor 202 is, for example, a photodiode, a pyrometer, color filters, optical gratings, preferably in combination with photodiodes, light sources and a combination thereof.

[0054] The non-optical sensor 203 is configured to detect signals of at least one non-optical parameter. The non-optical parameter is selected from the group comprising sound or noises, accelerations, positions, electromagnetic signals, X-ray radiation. The non-optical sensor 203 is, for example, a microphone and/or an accelerometer configured to detect sound and sound changes, an accelerometer to detect acceleration and/or position, a field coil configured to detect electromagnetic signals, and/or a radiation sensor configured to monitor a tube output dose and/or spectrum, such as a scintillator plus photodiode, a solid state detector, a MOSFET, or an ionization gauge and a combination thereof.

[0055] The computing unit 202 is configured to at least transmit the first and second signals detected from the optical sensor 201 and/or the signals detected by the non-optical sensor 203 to a remote system 300 external from the optical monitoring system 200. Additionally or alternatively, the computing unit 202 may analyze the measurement data and may calculate a result based on the analysis of the measurement data and may transmit the result of an analysis of the measurement data to the remote system 300. For this, the first and second signals detected by the optical sensor 201 and/or the signals detected by the non-optical sensor 203, and collected by the computing unit 202 can be time-stamped.

[0056] Further, the computing unit 202 may store the measurement data before transmitting them to the remote system 300. Thus, the computing unit 202 comprises elements for storing the measurement data, elements for analyzing the measurement data and/or elements for transmitting the data and/or the analysis result to the remote system 300. Examples for such elements include a signal processing system, a data processing system, and/or a programmable operating system.

[0057] For analyzing the measurement data, the computing unit 202 comprises an X-ray tube lifetime model including at least one predefined pattern for tube status and/or tube aging. Based on this tube lifetime model, the computing unit 202 can calculate the remaining lifetime of the X-ray tube 100 and/or predict its failure. The pattern comprises at least one value of the group of at least one event and/or at least one process and/or at least one predefined range and/or at least one threshold being indicative for tube age and/or tube wear status and/or tube vacuum status. For example, a pattern indicating a nearing filament failure can consist of a predefined difference compared to a value long before the filament failure, in black-body (thermal) radiation and optical radiation from the filament which result from a forming hot-spot. A pattern characteristic of a bearing failure may constitute new emerging line emissions from the liquid metal lubricant of the bearing, which start leaking into the tube vacuum.

[0058] Preferably, the pattern comprises a combination of n values and when a combination of k of these values is outside a normal interval, the interval being an n-dimensional volume, this indicates wear and/or instability over a predefined limit, wherein k is equal to or smaller than n. In this case, the computing unit 202 issues a warning, which is communicated to the remote system 300 by a communication unit 204. The communication unit 204 can be separate from the computing unit 202 and coupled to the computing unit 202 as shown in FIG. 4, or the communication unit 204 can be integrally implemented in the computing unit 202, as shown in FIGS. 2 and 3.

[0059] The communication between the computing unit 202 and the remote system 300 can be on a regular basis or warning-based. The communication on a regular basis, e.g. a daily basis, can comprise transmitting the measurement data and/or transmitting the result of the analysis of the measurement data. The remote system 300 can be either centrally or locally located, e.g. in at a tube manufacturing plant, a tube service center or in the building in which the X-ray tube 100 is located, for example a hospital. Further, the remote system 300 can be a computer device, such as a laptop, configured to be coupled to the computing unit 202 by a member of an X-ray tube maintenance service.

[0060] FIG. 4 shows another exemplary embodiment of the optical monitoring system 200 for monitoring the X-ray tube 100, additionally comprising the separate communication unit 204 and a power supply 205. The power supply 205 is preferably coupled to a power supply of the X-ray tube 100. The power supply 205 can additionally comprise an additional power storage unit (not shown in the FIGS. allowing to monitor the X-ray tube 100 for some time after the X-ray tube 100 has been powered off.

[0061] Referring back to FIG. 1, the letter A marks a position for at least one sensor of the optical monitoring system 200 preferably monitoring black-body radiation from a bearing and a back side of the anode 102, outside the tube envelope 105 but inside the tube housing 106. The letter B marks a position for at least one sensor of the optical monitoring system 200 preferably monitoring arcing between the cathode 101 and the anode 102 and/or for black-body radiation from a cathode cup (not shown) and the anode 102. The letter C marks an exemplary position for at least one sensor of the optical monitoring system 200 being arranged inside the tube envelope 105. The letter D marks a position for at least one sensor of the optical monitoring system 200 preferably monitoring arcing and/or black-body radiation from a focal track of the anode 102, and the letter E marks an exemplary position for at least one sensor of the optical monitoring system 200 being arranged outside the tube envelope 105 and outside the tube housing 106.

[0062] It should be noted that in case that the optical monitoring system 200 comprises more than one optical and/or non-optical sensor 201, 203, it is possible that these sensors are arranged at different positions inside and/or outside the X-ray tube 100.

[0063] FIG. 5 shows a flowchart of an exemplary embodiment of a method for monitoring an X-ray tube. A step S1 comprises detecting first signals of a first optical parameter and second signals of a second optical parameter by means of the at least one optical sensor 201 of the optical monitoring system 200, thereby generating measurement data. The first and second parameters are different from each other. Next, a step S2 comprises transmitting, by means of the computing unit 202 or the communication unit 204, the generated measurement data and/or a result of an analysis of the measurement data carried out by the computing unit 202 to a remote system 300, external from the optical monitoring system 200 and the X-ray tube 100.

LIST OF REFERENCE SIGNS

[0064] 100 X-ray tube [0065] 101 cathode [0066] 102 anode [0067] 103 anode rotor [0068] 104 anode stator [0069] 105 tube envelope [0070] 106 tube housing [0071] 107 evacuated volume [0072] 108 isolating, cooling medium [0073] 109 electron beam [0074] 110 X-ray radiation [0075] 200 optical monitoring sensor [0076] 201 optical sensor [0077] 202 computing unit [0078] 203 non-optical sensor [0079] 204 communication unit [0080] 205 power supply [0081] 300 remote system [0082] 400 method [0083] A, B, C, D, E position