JP2002280195A - X-ray tube, its malfunction detector, and device and sytem for x-ray ct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To objectively and accurately detect malfunction (deterioration) of a rotary anode type X-ray tube. SOLUTION: In the malfunction detector of a X-ray tube 40 wherein a cathode 43 and a rotary anode 45 having a surface slanting toward the cathode are placed face to face, and X-rays are generated by irradiating an electron beam onto the slanting surface, a vibration detecting part 1 to detect the vibration of the rotary anode 45 and a malfunction detecting part 2 to detect the condition of the malfunction of the X-ray tube 40 based on an AC component having a prescribed band, which is contained in a detected signal of the vibration detecting part 1 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray tube, an abnormality detection apparatus therefor, and an X-ray CT apparatus and system. More specifically, a cathode and a rotating anode having a slope with respect to the cathode are opposed to each other. The present invention relates to an X-ray tube that generates X-rays by irradiating the slope with an electron beam spot, an abnormality detection device therefor, and an X-ray CT device and system.

[0002] Today, in a X-ray CT apparatus, a rotating anode type X-ray tube is widely used because a relatively large X-ray dose (heat capacity) is continuously obtained. Wear of bearings that support the anode deteriorates the image quality of CT tomograms (artifacts occur).
In addition, since the life of the X-ray tube is not limited, it is desired that the deterioration state of the X-ray tube can be accurately grasped in advance and replaced appropriately.

[0003]

2. Description of the Related Art FIG. 17 is a view for explaining the prior art, and shows a partial sectional view of a conventional X-ray tube unit. In the figure, 50 'is an X-ray tube unit, 51 is an outer peripheral container (housing) made of metal (such as an aluminum container with a lead layer attached), 54 is an X-ray window through which X-rays are transmitted, and 40 is a rotary unit. An anode type X-ray tube, 41 is a glass envelope for keeping the inside of the tube in a vacuum, 42 is a filament made of tungsten or the like for generating thermoelectrons, 43 is a thermoelectron focusing electrode (cathode), 44 is a cathode A cathode sleeve covering and supporting the side structure, 45 is a rotating anode (target) made of an umbrella-shaped tungsten disk or the like, F is a focal point (slope) as an X-ray source, and 46 is formed integrally with the rotating anode 45 A rotating anode element (rotor) 47; a bearing rotatably supporting the rotor 46; 52 a cylindrical support member made of resin or the like for fixing and supporting the anode side of the X-ray tube 40; A switch that generates a rotating magnetic field It is a theta (stator coil).

With this configuration, when a rotating magnetic field (about 130 to 160 Hz) is generated in the stator 53, the rotor 46
Eddy current flows through the rotating anode 45 at a predetermined speed (7800 to
(About 9600 rpm). In this state, the thermoelectrons generated by the filament 42 are accelerated and focused by high pressure (about 120 kV) and collide with a small focal point F on the rotary anode 45 to generate X-rays. A part of this X-ray is emitted to the outside through the X-ray window 54 and used for X-ray imaging of the subject. In addition, insulating oil is filled and forcedly circulated in the outer peripheral container 51, whereby the insulation of the X-ray tube 40 is maintained and the X-ray tube 40 is cooled.

[0005] In this type of X-ray tube 40, the backlash movement of the rotating anode 45 caused by the wear of the bearing 47 is one of the main factors that determines the life of the X-ray tube 40.
I want to replace the X-ray tube 40 long before 0 becomes unusable.

[0006] In this respect, conventionally, a radiographing technician or a maintenance person approaches his / her ear near the X-ray tube unit 50 ', and mainly determines whether or not the echo sound (rattle sound, geen sound, etc.) is present or not and its size. The degree of deterioration of the X-ray tube 40 was determined.

[0007]

However, according to the above-described method for distinguishing between echoes, vibrations of bearings and the like are greatly reduced in the process of being transmitted to the ears via the insulating oil, the support member 52 and the like. , It is not easy to hear the echo. In addition, a cooling fan and the like are constantly rotating around the X-ray tube unit 50 ', and these noises make it difficult to hear the echo sound. In addition, since the judgment of deterioration differs from person to person, in the past, the X-ray tube 40 that can still be sufficiently used was replaced early, or the X-ray tube 40 that was thought to be still usable suddenly went down. ,
It often resulted in business interruption.

Further, as one factor of the life of the X-ray tube 40,
The filament 42 has a long service life. Conventionally, one filament 42 for forming an X-ray focal point (large focal point / small focal point) of each specified size is provided. However, if such a filament 42 is cut, the entire X-ray tube 40 must be replaced, even if there is no problem in other parts, which has hindered the work.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to provide a rotating anode type X.
X that can objectively and accurately detect abnormality (deterioration) of the tube
An object of the present invention is to provide an apparatus for detecting an abnormality of a wire tube. It is another object of the present invention to provide an X-ray tube that can extend the life of the X-ray tube. Still another object of the present invention is to provide a system capable of grasping the operating state of a plurality of X-ray tubes of this kind even in a remote place.

[0010]

The above-mentioned problem is solved, for example, by referring to FIG.
Is solved. That is, in the X-ray tube abnormality detecting device of the present invention (1), the cathode 43 and the rotating anode 45 having a slope with respect to the cathode face each other, and the X-ray is irradiated by irradiating the slope with an electron beam spot. In the abnormality detection device for the X-ray tube 40 that generates the vibration, the vibration detection unit 1 that detects the vibration of the rotating anode 45, and the X-ray tube 40 based on the AC component of a predetermined band included in the detection signal of the vibration detection unit 1. And an abnormality detecting section 2 for detecting an abnormal state of the above.

Preferably, in the present invention (2), in the present invention (1), as shown in FIG. 3 (or FIG. 7), for example, the vibration detecting unit 1 (the detecting element 60 and the vibration detecting unit 60A in FIG. Equivalent) are two or more X-ray detection elements a and b for detecting X-rays incident through the slit 61, and the dose received changes according to the movement of the X-ray generation source (focus) F. And an operational amplifier 71 that forms and amplifies a difference signal of the output of each X-ray detection element.

In FIG. 3, in an X-ray tube 40 in which a cathode 43 and a rotating anode 45 having a slope are opposed to each other,
Not only when the rotating anode (slope) 45 moves (vibrates) in the rotation (z) axis direction, but also when the rotating anode 45 moves (vibrates) in the xy plane (particularly in the y-axis direction),
The X-ray focal point F moves (vibrates) in the z-axis direction due to the interaction between the electron beam traveling straight in the z-axis direction and the inclined surface of the rotating anode.

Therefore, in the present invention (2), the focus F
X-rays are detected by, for example, two X-ray detection elements a and b through the slit 61, and X-ray detection is performed so that the dose received by the X-ray detection elements a and b changes according to the movement of the focal point F. Elements a and b are arranged. In this state, the operational amplifier 7
1 to form and amplify a difference signal between the outputs a and b of each X-ray detection element. Therefore, it is possible to effectively detect an AC component in a predetermined band accompanying the vibration of the rotating anode 45.

Preferably, in the present invention (3),
In the present invention (1), for example, as shown in FIG. 8, the vibration detecting unit 1 includes two or more X-ray detecting elements a and b for detecting the incident X-ray with the inclined surface of the rotary anode 45 as a knife edge. An X-ray detector is arranged such that the dose received by at least one X-ray detection element a or b changes according to the movement of the X-ray generation source (focal point) F, and a difference signal between the outputs of the respective X-ray detection elements. And an operational amplifier for forming and amplifying.

In the present invention (3), the slit 6
Instead of providing 1, the inclined surface (target) of the rotating anode 45 is used as a knife edge (instead of the slit 61), and the X-ray from the X-ray focal point F is guided to, for example, two X-ray detecting elements a and b. With this configuration, the shadow of the knife edge (slope) moves relatively quickly on the X-ray detecting elements a and b with the vibration of the rotary anode 45, so that the AC component in a predetermined band due to the vibration of the rotary anode 45 is effectively used. Can be detected.

Preferably, in the present invention (4),
In the present invention (1), for example, as shown in FIG.
The vibration detection unit 1 is opposed to the X-ray tube 40 with the subject 100 interposed therebetween, and has a large number of X-ray detection elements arranged in the channel direction in two rows A and B in the body axis (z) direction of the subject 100 or more. An X-ray detector 81 arranged between the X-ray tube 40 and the X-ray detector 81 for limiting the X-ray irradiation width of the subject 100 in the body axis direction, , X-ray detector 8
1 for the predetermined reference channel detection elements Ra, R
and an operational amplifying unit for forming and amplifying a difference signal of each X-ray detection output for two or more columns per b.

According to the present invention (4), the existing collimator 80 and the X-ray detector 81 in the X-ray CT apparatus are effectively used to effectively reduce the AC component in a predetermined band accompanying the vibration of the rotary anode 45. Can be detected.

Preferably, in the present invention (5),
In the present invention (1), for example, as shown in FIG.
The vibration detection unit 1 includes an acceleration sensor 60 fixed to the X-ray tube 40, and an amplification unit 60A that converts a detection output of the acceleration sensor into an electric signal.

According to the present invention (5), the vibration of the X-ray tube 40 is detected by the acceleration sensor 60 fixed to the X-ray tube (which may be inside or outside), so that the rotating anode 4
The AC component of a predetermined band accompanying the vibration of No. 5 can be effectively detected.

Preferably, in the present invention (6), in the above-mentioned present invention (1), for example, as shown in FIG. 3, the abnormality detecting section 2 (corresponding to 60B in FIG. It includes a filter 72 for extracting an AC component in a predetermined band, and detects an abnormal state of the X-ray tube based on the signal amplitude of the filter output.

In such a configuration, when the X-ray focal point F moves relatively slowly due to the thermal expansion / contraction of the rotary anode 45, no output appears on the high-pass filter 72, but the wear of the bearing 47 and the like ( X-ray focus F due to play
Moves (vibrates) relatively quickly, a remarkable output appears in the high-pass filter 72, and the vibration of the rotating anode 45 (ie, abnormality / deterioration of the X-ray tube 40) based on the signal amplitude.
Can be objectively and accurately detected.

Preferably, in the present invention (7),
In the present invention (1), for example, as shown in FIG.
The abnormality detection unit 2 (corresponding to 60B in FIG. 11) includes a frequency analysis unit (FFT) 25 for obtaining a frequency component of a detection signal of the vibration detection unit, and based on a magnitude of a predetermined frequency component output from the frequency analysis unit. It detects an abnormal state of the X-ray tube.

In the present invention (7), the frequency of the vibration detection signal of the rotating anode 45 is analyzed, so that the X-ray tube 4
It is possible to make a more sophisticated and accurate judgment on the abnormal state of 0.

The X-ray CT apparatus according to the present invention (8) includes a rotating anode type X-ray tube and an X-ray detector opposed to each other with the subject interposed therebetween. An X-ray CT apparatus for reconstructing a CT tomographic image of a subject based on the X-ray tube abnormality detection apparatus according to any one of the present inventions (1) to (7). Therefore,
It is possible to use the X-ray tube 40 without wasting its original life without hindering the X-ray CT imaging operation.

In the X-ray tube of the present invention (9), as shown in FIG. 15, for example, a cathode 43 and a rotating anode 45 having a slope with respect to the cathode face each other, and an electron beam spot on the slope is formed. In the X-ray tube that generates X-rays by irradiation of, two filaments 42a and 42b arranged in parallel with the same size and shape for generating thermoelectrons,
One of the terminals is connected to a common power supply, and the other terminal is configured to be switchable by a switch means 58 and supplied with power.

According to the present invention (9), first, the X-ray tube 40 is operated by supplying power only to the filament 42a, and after the life of the filament 42a has expired, the power is supplied only to the filament 42b to supply the X-ray tube 40. Get it up and running. As a result, the life of the X-ray tube 40 can be approximately doubled with respect to the life of the filament 42.

The X-ray CT apparatus according to the present invention (10) includes a rotating anode type X-ray tube and an X-ray detector opposed to each other with the subject interposed therebetween. An X-ray CT apparatus for reconstructing a CT tomographic image of a subject based on the X-ray tube according to the present invention (9).

The monitoring system for an X-ray tube of the present invention (11), for example, as shown in FIG. 16, monitors the vibration of the rotating anode detected for the own rotating anode type X-ray tube or the disconnection of the filament. A plurality of X-ray CT apparatuses 90 for transmitting data, and a plurality of X-ray CT
A central monitoring device 90 is connected to the device 90 and collects monitoring data from each X-ray CT device and collectively monitors the operating state of the X-ray tube.

According to the present invention (11), a plurality of X-ray CT
With an abnormal state of the X-ray tube in the apparatus 90 _{1-90 3} or the like can efficiently monitored collectively in a central monitoring unit 90, to reduce the number standing stock of the X-ray tube by good judgment of tube replacement time Possible, and thus a plurality of X-ray CT
A 0 ₁ ~90 X-ray CT system, such as consisting of ₃ or the like can be efficiently operated.

[0030]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the same reference numerals indicate the same or corresponding parts throughout the drawings.

FIG. 2 is a block diagram of a main part of the X-ray CT apparatus according to the embodiment, showing an example of application of the present invention to the X-ray CT apparatus. The X-ray CT apparatus can be roughly divided into a scanning gantry unit 30 for performing an axial / helical scan of the subject 100 using the X-ray fan beam XLFB, and a subject 1
It is composed of an imaging table 20 on which 00 is placed and moved in the direction of the body axis CLb, and a remote operation console 10 operated by an imaging technician or the like.

In the operation gantry section 30, 50 is an X-ray tube unit, 40 is a rotating anode type X-ray tube, 45 is its rotating anode, and 50A is a tube voltage kV and a tube current m of the X-ray tube 40.
A, an X-ray control unit for controlling the X-ray irradiation time Sec per gantry rotation, etc., 60 is a detection unit for detecting vibration of the rotating anode 45, and 60A is a vibration detection unit for performing detection signal processing of the detection unit 60. , 60B are X-ray tubes 4 based on AC components of a predetermined band included in the detection signal of the vibration detection unit.
An abnormality detector that detects an abnormal (deteriorated) state of 0,
A collimator for limiting the irradiation range of the ray (mainly in the direction of the subject body axis CLb), a collimator control unit 80A, and a large number (about n = 1000) of X-ray detection elements 81 arranged in the channel CH direction are body axes CLb. X-ray detectors (twin detectors) arranged in, for example, two rows A and B in the direction, and 82, projection data g _A (X, θ) and g _{B of the} subject 100 based on the detection signal of the X-ray detector 81. A data acquisition unit (DAS) 30A for generating and acquiring (X, θ) is a rotation control unit for rotating the scanning gantry (X-ray imaging system) around the body axis CLb.

The X-ray detector 81 may be one in which a number of X-ray detection elements arranged in the channel CH direction are arranged in a single row in the direction of the body axis CLb (single detector), or may be three or more. An array (multi-detector) may be used.

In the operation console unit 10, X is X
Central processing unit for performing main control and processing (scan control, CT tomographic image reconstruction processing, X-ray tube 40 deterioration determination processing, etc.) of the X-ray CT apparatus, 11a is its CPU, and 11b is CPU 11
a, a main memory (M
M) and 12 are input devices for inputting commands and data including a keyboard and a mouse, etc., and 13 is a display device (CR) for displaying a scan plan or a scanned and reconstructed CT tomographic image.
T) and 14 are control interfaces for exchanging various control signals CS and monitor signals MS between the CPU 11a and the operation gantry unit 30 and the imaging table 20, and 15 temporarily stores projection data from the data collection unit 82. The data collection buffer 16 stores and stores projection data from the data collection buffer 15 and also stores various application programs necessary for control and operation of the X-ray CT apparatus, various calculation / correction data files, and the like. A secondary storage device (hard disk device or the like) 17 is a communication control unit (CO) for connecting to a line (network, LAN, etc.).
M).

With such a configuration, the X-ray fan beam XLFB from the X-ray tube 40 passes through the subject 100 and simultaneously enters the detection rows A and B of the X-ray detector 81. The data collection unit 82 integrates each detected current signal of the X-ray detector 81 and performs A / A
D-converted and corresponding projection data g _A (X, θ), g
_B (X, θ) and generate them in the data collection buffer 1
5 is stored. Next, the same projection is performed at each view angle θ at which the operation gantry 30 is slightly rotated, and thus projection data for one rotation of the scanning gantry is collected and accumulated. Further, the imaging table 20 is intermittently / continuously moved in the body axis direction of the subject 100 in accordance with the axial / helical scan method, and thus all projection data on a required imaging region of the subject 100 is collected and accumulated. Are stored in the secondary storage device 16. And, CPU11a
In parallel with the above scan or after the scan,
A CT tomographic image of the subject 100 is reconstructed based on the obtained projection data and displayed on the display device 13. Hereinafter, an abnormality detection method for an X-ray tube according to the present invention will be described in detail.

FIG. 3 is a diagram showing the configuration of the X-ray tube abnormality detection system according to the first embodiment, showing a case where the vibration of the rotary anode 45 is detected by two X-ray detection elements through slits. I have. In the figure, the basic configuration of the X-ray tube unit 50 including the X-ray tube 40 may be the same as that described with reference to FIG. However, here, the following configuration for detecting the vibration of the rotating anode 45 is added.

That is, 60 is an X-ray detection unit, and 61 is
The slit plate, 62 is an X-ray detection block, and a and b are X
The line detecting element 60A is connected to the rotating anode 45 (that is, the focal point F).
The vibration detection unit 71 forms a difference signal between the X-ray detection outputs a and b.
Operation amplification section for generating and amplifying, 60B is the detection of vibration detection section
Of the X-ray tube based on the AC component of the predetermined band contained in the signal
An abnormality detector 72 for detecting an abnormal state is provided with an operational amplifier 71
Output e_yzHigh-pass filter that extracts a predetermined high-frequency component from
Filter (HPF) 73 has its filter output f _yzAmplitude
Detector (DET) 74 for detecting the level
Force g_yzA / D converter (A / D), 75 is the operational amplifier
Output e_yzLow-pass filter that extracts a predetermined low-frequency component from the
Filter (LPF), 76 is the amplitude level of the filter output
(DET) 77 detects the A of the detection output.
/ D converter (A / D).

The vibration detecting section 60A may be constituted mainly of an analog circuit, or may be constituted mainly of a digital circuit (hardware, DSP + software, etc.). The abnormality detector 60B extracts, detects, and A / D-converts the high-frequency component of the vibration detection signal. The abnormality of the X-ray tube 40 based on this is determined by, for example, the CPU 11a.

The X-ray detection unit 60 comprises a slit plate 61 and an X-ray detection block 62,
It is provided apart from the inside and outside of the wire tube 40. With this arrangement, the optical magnification m = q / p for detecting the fine movement of the X-ray focal point F can be increased, and the detection sensitivity of the focal point movement is increased.

The front view of the X-ray detection block 62 is shown in FIG. The slit plate 61 includes a material that does not transmit X-rays (such as a lead layer), and has a rectangular slit opening w corresponding to the center of the X-ray detection block 62. The X-ray detection block 62 is also surrounded by a rectangular container (including a lead layer or the like) that does not allow X-rays to pass therethrough. Having. According to this structure, it is possible to effectively prevent the scattered X-rays that have been emitted without passing through the slit opening w. Further, two rectangular X-ray detection elements a and b are provided on the bottom surface of the X-ray detection block 62 as shown in the figure. X-ray detection elements a and b
Includes a semiconductor light detection element such as a photodiode, and may be, for example, the same as the channel detection element included in the scanning X-ray detector 81. Hereinafter, each detection signal of the X-ray detection elements a and b will be described. Also called detection signals a and b.

Preferably, such an X-ray detection unit 60 is arranged at a position facing the focal point F immediately below the anode rotation axis CLt. In this arrangement, the X-ray focal point F is shifted vertically (y
When moving in the (axial) direction and in the left-right (z-axis) direction, the amount of X-rays incident on the detection elements a and b changes. Therefore, this X
The line detection unit 60 has detection sensitivity to movement of the focal point F in the z-axis and y-axis directions.

Next, the operation of detecting the movement of the rotating anode (slope) 45 as the movement of the X-ray focal point F using the X-ray detection unit 60 will be described.

FIGS. 4 to 6 are diagrams (1) to (3) for explaining a vibration detecting operation according to the first embodiment. FIG. 4 shows a case where the rotating anode 45 vibrates (moves) in the z-axis direction. Is shown. The rotating anode 45 has a z
In addition to vibrating in the axial direction, the rotating anode 45 has thermal expansion /
By contraction, it moves relatively slowly, but largely in the z-axis direction. Since the emission direction of the electron beam is fixed in the z-axis direction, the rotating anode (slope) 4
When 5 moves in the z-axis direction, the focal point F also moves in the z-axis direction.

FIG. 4A shows a case where the rotating anode 45 (focal point F) is at the reference position, and at this time, the X-rays passing through the slit w are adjusted so as to be equally incident on the detection elements a and b, respectively. Have been. FIG. 4B shows a case where the rotating anode 45 (focal point F) has moved to the left, and at this time, the slit w
X-rays that have passed through tend to decrease at the detection element a and increase at the detection element b. FIG. 4C shows the rotating anode 4.
This shows a case where 5 (focal point F) has moved to the right. At this time, the X-rays passing through the slit w tend to increase in the detection element a and decrease in the detection element b.

FIG. 5 shows a case where the rotating anode (slope) 45 moves (vibrates) in the y-axis direction. The vibration in the y-axis direction is a typical vibration that can be caused by the wear of the bearing 47. Since the emission direction of the electron beam is fixed in the z-axis direction, when the rotating anode (slope) 45 moves in the y-axis direction, the X-ray focal point F moves in the z-axis direction accordingly. When the bearing 47 is worn, the rotating anode 45 vibrates in the xy plane. Usually, it is sufficient to detect the vibration in the x-axis or y-axis direction.
A case where axial vibration is detected will be described.

FIG. 5A shows a case where the rotating anode 45 (focal point F) is at the reference position as in the case of FIG. 4A, and the X-rays passing through the slit w at this time are detected. Adjustments are made so that an equal amount of light is incident on each of the elements a and b.
FIG. 5B shows a case where the rotating anode 45 moves upward (that is, the focal point F moves to the right). At this time, the X-rays passing through the slit w increase in the detection element a and decrease in the detection element b. Tend to. FIG. 4C shows a case where the rotating anode 45 moves downward (that is, the focal point F moves to the left). At this time, the X-rays that have passed through the slit w decrease in the detection element a and decrease in the detection element b. It tends to increase. As described above, the rotating anode 4 generated by the wear of the bearing 47 and the like
The vibration No. 5 can be effectively detected by detecting the vibration of the X-ray focal point F in the z-axis direction.

FIG. 6 shows the signal processing operation in the operational amplifier 71. The operational amplifier 71 obtains the difference signal _eyz based on the input detection signals a and b by, for example, the equation (1), _eyz = k · {(ab) / (a + b)} (1). Here, k is a coefficient that determines the detection sensitivity of the difference signal _eyz .

FIG. 6A shows a numerical example. Here, the coefficient k is set to 10. In the figure, both detection signals a = b (for example, both are 5 V) at the item number 6,
The values of the detection signals a and b change symmetrically with respect to the center, and accordingly, change substantially linearly within the range of the difference signal e _yz = ± 10 _V.

FIG. 6 (B) shows a graph thereof. However,
The horizontal axis represents item numbers 1 to 11. The difference signal e _yz by the action of the (1) normalization term {× 1 / (a + b )} contained in the equations, regardless of the large / small of the X-ray energy (kV, mA), always -10 V ≦ It will change within the range of e _yz ≦ 10V. Note that a predetermined bias value β (for example, β =
By adding 10 V), the dynamic range of the difference signal e _yz can be changed to a positive range (0 V ≦ e _yz ≦ 20 V).

Returning to FIG. 3, when the rotating anode 45 moves relatively slowly due to its thermal expansion / contraction,
The differential signal e _yz output from the operational amplifier 71 appears as a DC or low frequency signal of a frequency (about 0 to several Hz) according to the moving speed. when vibration, the difference signal e _yz of the output of the operational amplifier 71, which contains the high-frequency component having a frequency corresponding to the rotational speed (about 130~160Hz).

Therefore, a high-frequency component of a predetermined band (for example,> 100 Hz) is extracted from the difference signal e _yz by the high-pass filter 72, and the amplitude of the output f _yz is detected by the detector 73, and the detected output g _yz is obtained. A / D converter 74
A / D conversion is performed. The operation diagram is shown in the inset (b). Further, the rotating anode 45 thus obtained (focal point F)
Vibration detection signal s _yz of is sent to the CPU11a via the control interface 14, where the degree of deterioration of the X-ray tube 40 is analyzed and monitored.

On the other hand, a low-frequency component of a predetermined band (for example, <several tens Hz) is extracted from the difference signal _eyz by a low-pass filter 75, and the amplitude (peak value or average value level) of the output is detected by a detection unit 76. The A / D converter 74 A / D converts the detection output. The movement detection signal OF of the rotating anode 45 (focal point F) thus obtained is sent to the CPU 11a via the control interface 14, and
Here, for example, the focal point F due to thermal expansion / contraction of the rotary anode 45
Is analyzed and monitored.

FIG. 7 is a diagram showing a configuration of an X-ray tube abnormality detection system according to the second embodiment.
Shows a case where the rotating anode 45 has detection sensitivity not only in the above-described vibration in the y- and z-axis directions but also in the vibration in the x-axis direction. In the X-ray detection unit 60 of this example, the slit plate 61 and the X-ray detection block 62 are integrated, so that handling and adjustment of such an X-ray detection unit 60 are easy.

The X-ray detection unit 6 is shown in FIG.
0 shows a front view. The slit plate 61 on the surface has a square slit opening (X) corresponding to the center of the X-ray detection block 62.
Line window) w. On the bottom surface of the X-ray detection block 62, four X-ray detection elements a to d of each square are provided as shown in the figure. Hereinafter, the respective detection signals of the X-ray detection elements a to d are also referred to as detection signals a to d.

Preferably, the X-ray detection unit 60
Is disposed at a position facing the X-ray focal point F immediately below the anode rotation axis CLt. In this arrangement, the X-ray focal point F is shifted vertically (y
(X-axis) direction and in the left-right (z-axis) direction, the X-ray dose incident on each set of the detection elements (a, b) and (c, d) changes. Further, when the X-ray focal point F moves in the front-back (x-axis) direction on the paper surface, the X-ray dose incident on each set of the detection elements (a, d) and (b, c) changes. Therefore, the X-ray detection unit 60 has detection sensitivity to the movement (vibration) of the X-ray focal point F in all directions.

Corresponding to such an X-ray detection unit 60
The vibration detection unit 60A and the abnormality detection unit 60B
A system signal processing circuit is provided. That is, the operational amplifier 7
1a is based on the input detection signals a to d,
Difference signal e_yzIs given by, for example, equation (2), e_yz= K · {[(a + b)-(c + d)] / (a + b + c + d)} (2), and finally, based on this, y, z of the X-ray focal point F
Axial vibration component signal s _yzIs detected. Operational amplifier 7
1b is a difference in the x-axis direction based on the input detection signals ad.
Signal e_xIs given by the equation (3), e_x= K · {[(b + c)-(a + d)] / (a + b + c + d)} (3)
Vibration component signal s_xIs detected. Thus obtained
Each vibration detection signal s_yz, S_xIs the control interface 14
Is sent to the CPU 11a via the
The degree of conversion is analyzed and monitored. Thus, in the second embodiment,
The X-ray detection unit 60 according to the form has a
Since it has detection sensitivity to vibration in the azimuth,
Arranged at any position inside / outside the wire tube 40 and at any posture
Can be set so as to face the X-ray focal point F.

FIG. 8 is a view showing a configuration of an X-ray tube abnormality detection system according to the third embodiment. Instead of providing the slit 61, the inclined surface of the rotary anode 45 acts as a knife edge. It shows the case where it is used. The X-ray detection unit 60 includes an X-ray detection block 62,
It consists of an X-ray window provided in front of it to seal the inside.

The X-ray detecting unit 6 is shown in the inset (a).
0 shows a front view. On the bottom surface of the X-ray detection block 62, two rectangular X-ray detection elements a and b are provided as shown. Preferably, the X-ray detection unit 60 is arranged in a position and posture immediately below the anode rotation axis CLt such that the inclined surface of the rotating anode 45 becomes a half shadow as illustrated. In this arrangement, when the rotating anode 45 moves in the vertical (y-axis) direction and the horizontal (z-axis) direction in the figure, the X-ray dose incident on the detection elements a and b changes. Therefore, the X-ray detection unit 60 has detection sensitivity to the movement (vibration) of the rotating anode 45 in the y and z axis directions.

FIG. 9 is a diagram for explaining a vibration detecting operation according to the third embodiment. Since the operation of the focal point F when the rotating anode 45 moves (vibrates) in the z-axis direction is obvious, the operation when the rotating anode 45 moves in the y-axis direction will be described here.

FIG. 9A shows a case where the rotating anode 45 is at the reference position. At this time, the X-rays emitted along the inclined surface (knife edge) of the rotating anode 45 enter only the detecting element a, for example. , Are adjusted so that they do not enter the detection element b. FIG. 9B shows a case where the rotating anode 45 moves to the upper side of the drawing (that is, the focal point F moves to the right). At this time, the X-rays emitted along the slope of the rotating anode 45 are input to the detection element a. At the same time, the detection element b tends to increase. FIG. 4C shows a case where the rotating anode 45 has moved to the lower side of the figure (that is, the focal point F has moved to the left).
X-rays emitted along the slope of No. 5 do not enter the detection element b and tend to decrease at the detection element a.

Referring back to FIG. 8, the vibration detection unit 60A and the abnormality detection unit 60B provide the above-described input detection signals a and b.
Based on the, y of the rotary anode 45, to detect a vibration component signal s _yz in the z-axis direction, and notifies the CPU11a via the control interface 14 this.

FIG. 10 is a diagram showing the configuration of an X-ray tube abnormality detection system according to the fourth embodiment. An X-ray imaging system (X-ray tube 40, collimator 80, X-ray detection The case where the present invention is realized by effectively utilizing the configuration of the device 81) is shown. Generally, in this type of X-ray imaging system, X
When the line focus F is at its reference position F0, the X-ray detector 8
X-ray fan beam XLFB of equal amount for each of detection rows A and B
The position of the collimator 80 in the body (z) axis direction is adjusted so that is irradiated. When the X-ray focal point F moves from the reference position F0 to -F1 or + F2 due to the thermal expansion / contraction of the rotary anode 45, the collimator 8 responds accordingly.
0 is moved in the z-axis direction, so that each detection row A, B
Is automatically adjusted so that the same amount of X-ray fan beam XLFB is irradiated.

Conventionally, this kind of feedback control has a low-speed response corresponding to the thermal expansion / contraction of the rotary anode 45, and the X-ray amount incident on each of the detection rows A and B increases rapidly with the slight vibration of the rotary anode 45. Even if there is a slight change in frequency,
I didn't know anything about this.

In the fourth embodiment, each detection signal Ra and Rb is extracted from each X-ray detection element of the reference channel R in the detection rows A and B, and these are detected by the same vibration detection as in FIG. Unit 60A, abnormality detection unit 60
By entering the B, y of the rotary anode 45, to detect the vibration component s _yz in the z-axis direction, and notifies the CPU 11a.

By feeding back the separately detected offset movement amount detection signal OF of the X-ray focal point to the collimator control unit 80A, this signal can be used for the movement control of the collimator 80.

FIG. 11 is a diagram showing a configuration of an X-ray tube abnormality detection system according to the fifth embodiment. FIG. 11A shows another example of a vibration sensor (acceleration sensor) 60 as a detection unit 60. FIG. Hereinafter, this detection unit 60 is called a vibration sensor. The vibration sensor 60 has a structure in which a disc-shaped piezoelectric ceramic 112 and a metal plate 113 are bonded together to form a unimorph-type piezoelectric element, which is peripherally supported by an elastic body 111 and attached to an outer case 114. . The outer case 114 can be fixed to a vibration detection target by a mounting hole 115.

When mechanical vibration is applied to such a vibration sensor 60, the electric charge Q proportional to the acceleration g, Q = A · d · m · g, where A is a constant determined by the structure of the piezoelectric element d: Piezoelectric constant m: Effective mass of piezoelectric element is generated. As the open output voltage V, V = Q / C where C: the capacitance of the piezoelectric ceramics is detected by the charge Q.

The resonance frequency f0 of this piezoelectric element is
The size and the Young's modulus of the metal plate 113 are determined. When the resonance frequency is equal to or lower than f0, the vibration system is elastically controlled. Therefore, in this range, the output voltage V is always proportional to the acceleration g regardless of the frequency. In the fifth embodiment, considering that the basic vibration frequency generated from the normal X-ray tube 40 is about 130 to 160 Hz, the resonance frequency f0 of the vibration sensor 60 is sufficiently higher than this. For example, a frequency of about 2 kHz to 3 kHz is selected.

FIG. 11B shows the X-ray tube 4 of the vibration sensor 60.
An example of attachment to 0 is shown. Preferably, the vibration sensor 60 is connected to the rotating anode 45 or the bearing 4 as shown in FIG.
7 is fixed (screwed, adhered, etc.) to the outer case 41 near. In this way, the acceleration g due to the vibration (play) of the rotating anode 45 is applied perpendicular to the plane of the piezoelectric element, and high detection sensitivity can be obtained. Note that the vibration sensor 6 is
0 may be integrated and mounted.

Alternatively, as shown in FIG.
May be fixed to the support member 52. In this way, the play of the bearing 47 can be detected efficiently. Alternatively, the vibration sensor 60 may be fixed to the haze 51 of the X-ray tube unit 50 as shown in FIG. Of course, the fixed position and posture of the vibration sensor 60 are not limited to the above, and various other modes are conceivable.

FIG. 11C shows a vibration detector (amplifier) 60.
A and an example of an abnormality detection unit (frequency analysis unit) 60B are shown. In the figure, a detection signal of a vibration sensor 60 is amplified by an amplifier (charge amplifier) 60A, A / D converted by an A / D converter 23, and output as sampling data PD.

An example of the abnormality detection unit 60B is a DSP (Digital
Signal Processor), in which various functional blocks realized by executing a DSP program are shown. Here, reference numeral 25 denotes a Fourier transform unit (FFT / D) which Fourier-transforms a vibration signal related to each input sampling data PD at high speed and outputs frequency component data FD representing the magnitude of each frequency component (vibration component).
FT) and 26 are frequency component data F output from the FFT 25
A filter unit for removing predetermined frequency component data from D;
Reference numeral 27 denotes an inverse Fourier transform unit (inverse FFT / inverse DFT) for performing an inverse Fourier transform on the output of the filter unit 27 to generate a monitored sound (audio) data AD after filtering, and 28 designates FIG.
The various analysis data DD (including the sampling data PD) and the CPU 11
Peripheral I that exchanges command C3 from a
/ O section (PIO).

The CPU 11a collects the analysis data DD from the abnormality detection unit 60B, edits the analysis data DD into a predetermined output format and creates the monitoring data MD / AD, and displays them on the display device 13, a printer or a speaker (not shown). Output to Hereinafter, the output mode of the monitoring data MD / AD will be specifically described.

FIGS. 12 and 13 are views (1) and (2) showing a display mode of the X-ray tube vibration monitoring data MD. FIG. 12 shows a case where each frequency component data FD is displayed on the frequency axis. ing. FIG. 12A shows a case where the X-ray tube 40 is normal, in which the horizontal axis represents the frequency and the vertical axis represents the intensity of the frequency component FD. In the figure, when the X-ray tube 40 is normal, the frequency component FD of the fundamental vibration corresponding to the rotation speed of the rotating anode 45 is shown.
1 and its frequency component FD2 based on mechanical harmonic vibration
Etc. appear relatively conspicuously. Further, a slight beat component FD3 appears due to mechanical harmonization of a plurality of vibration components. In any case, the generation pattern of the vibration component when the X-ray tube 40 is normal (during replacement) is relatively simple (pure) as shown in the figure. It has become.

FIG. 12B shows a case where the rotation mechanism of the X-ray tube 40 has deteriorated. When the rotation mechanism of the X-ray tube 40 is deteriorated, mechanical stress confined in the mechanism is diverted, thereby increasing, for example, the beat component FD3. Also stimulated by this, a new beat component FD5
And a harmonic component FD4 are generated and increased. Thus, X
The generation pattern of the vibration component when the wire tube 40 is deteriorated is more complicated as shown in the drawing, and if this is compared with an audible sound, the sound becomes muddy. Furthermore, rattling noise and a goon sound like a jet plane are generated, and if left unchecked, the X-ray tube 40 will soon be damaged.

In the fifth embodiment, for example, when the user views the spectrum display on the display device 13 as appropriate,
The deterioration state of the wire tube 40 can be quantitatively and objectively grasped.
The degree of deterioration can be easily grasped by comparing the states of FIG. 12A and FIG. 12B. Preferably, FIG.
As shown in (1), the respective vibration components at the time of tube replacement are simultaneously displayed by dotted lines or by changing colors with respect to the respective vibration components at the present time, so that comparison is easy.

Alternatively, the user looks at the display of FIG. 12 (A) in advance and checks the normal vibration components FD1, FD1,
FD2 or the like may be extracted and this portion may not be displayed. Generally, the normal vibration components FD1, FD2, etc. and their amplitudes are different for each X-ray tube 40, and these can be effectively eliminated by the above method. FIG. 12 in this case
In (B), from the state where there is no vibration line segment at the beginning of tube replacement,
Since some remarkable vibration components appeared, the X-ray tube 4
0 can be determined as deterioration. In addition, the threshold value TH for determining deterioration is determined in advance.
Is set in the CPU 11a, the CPU 11a can automatically determine the deterioration.

The above-mentioned display of the vibration spectrum may be performed all the time, or may be performed at the request of the user. In the latter case, the analysis data DD collected periodically is stored in the disk 16, read out and edited at the request of the user, and output to the display device 13. Alternatively, the analysis data D is not stored in the disk 16 and the analysis data D
D is collected and edited and output to the display device 13. Note that, even in this case, the monitoring data in the initial state of the X-ray tube 40 is held.

FIG. 13A shows vibration data P of the X-ray tube 40.
The maximum value PD periodically (or intermittently) detected for D
The case where the change of the moving average value of max or the maximum value is plotted and displayed on the time axis is shown, the horizontal axis is the elapsed time (year, month, day, hour, minute, etc.) since the X-ray tube 40 was replaced, and the vertical axis is the vertical axis. X-ray tube 4
The intensity PD has a vibration amplitude of 0. In general, the instantaneous vibration data PD detected from the X-ray tube 40 includes a beat wave component due to interference (harmony) between a plurality of vibration components, and the instantaneous waveform fluctuates in a complicated manner. Therefore, the maximum value PDmax of the vibration data PD or the moving average value of the maximum value is periodically collected, and these are plotted and displayed on the time axis.

In FIG. 13A, at the beginning of the replacement of the X-ray tube 40, the vibration amplitude is relatively small and stable. However, after a considerable operating time has passed, once the vibration amplitude once increases due to the deterioration of the rotating part, the deterioration induces new deterioration thereafter, and the maximum value PDmax gradually increases as shown in the figure. Therefore, if the user looks at the display, the deterioration state of the X-ray tube 40 and the progress state thereof can be grasped quantitatively and objectively. Note that the threshold value TH1 may be displayed at the same time and used for determining the replacement time of the X-ray tube 40. Or the threshold T in advance
H1 is set in the CPU 11a.
It may be used for the automatic determination of the replacement time of the X-ray tube 40 by a.

FIG. 13B shows the maximum value FDmax detected periodically (or intermittently) or the moving average value of the maximum value for one or more frequency components FD of interest of the vibration of the X-ray tube 40. This shows a case where the change is plotted and displayed on a time axis. Referring to the example of the transition pattern in the figure, the normal vibration component FD1max has not changed much from the beginning. Rather, the amplitude of the vibration energy in the pipe is somewhat reduced as a result of the distribution and distribution of the vibration energy being complicated. On the other hand, the abnormal vibration component FD4max is small at first, but increases almost uniformly from a relatively early point in time after the tube replacement. However, the traveling speed is relatively slow, and has reached a plateau at present. Another abnormal vibration component FD
Although 3max has been changing at a constant level from the beginning, it rapidly increases from a certain point in time, and has a momentum exceeding the threshold value TH2 at present. At this time, an abnormal vibration component FD5max is newly generated and is growing vigorously.

The progress of such tube deterioration is different for each X-ray tube, and the present invention makes it possible to grasp quantitatively and objectively for each X-ray tube. Incidentally, the user in this case can determine that the X-ray tube 40 is time to replace. The CPU 11a may be configured to analyze such a change pattern of each vibration component and automatically determine the replacement time of the X-ray tube 40. Further, the user can arbitrarily set in advance which vibration component to use (monitor).

Next, a case where the abnormal sound is monitored by ear based on the vibration data detected from the X-ray tube 40 will be described. In FIG. 2, the CPU 11a in this case outputs monitoring sound data AD collected from the abnormality detection unit 60B to a baseband processing unit (not shown). At this time, as described above, the user looks at the display of FIG.
The vibration components FD1, FD2, etc. generated from the wire tube 40 are extracted, and the vibration components FD1, FD2, etc. are removed as shown in FIG.
To the filter 26. Upon receiving the instruction C3, the filter 26 removes the specified vibration components FD1, FD2, etc. from the input frequency component data FD. Also reverse FF
T27 generates the monitoring sound data AD after filtering.
In FIG. 2, the baseband processing unit performs monitoring sound data A
D is converted to an analog signal AS, amplified, and output to a speaker (not shown) provided near the console.

In this case, the user cannot hear any sound when the X-ray tube 40 is replaced. Then, when the abnormal vibration components FD3, FD4, etc. occur soon, even if the magnitude is small, the occurrence of such an abnormal sound can be clearly heard by the so-called human auditory masking effect. In addition, the user can clearly listen in a quiet place (such as a monitoring office) away from the scanning gantry unit 30. Therefore, anyone can quantitatively and objectively grasp the occurrence and magnitude of such an abnormal sound. In addition, as described above, the designated vibration component FD
The original vibration data PD may be directly output to the baseband processing unit without removing 1, FD2, and the like.
In this case, the user can hear a faithful vibration sound of the X-ray tube including a normal sound without being disturbed by noise around the X-ray tube 40 or the like.

FIG. 14 is a diagram showing the configuration of the X-ray tube abnormality detection system according to the sixth embodiment. The configuration for outputting the deterioration (vibration) sound of the X-ray tube 40 to a speaker is constituted by an analog circuit. It shows the case where it is done. The signal detected by the vibration sensor 60 is amplified by a vibration detection unit 60A, and after a frequency component in a predetermined band is removed by a band elimination filter (BEF) 21, the power is amplified by an output stage amplifier 24, and the signal is amplified by a speaker 51. Is output. Band removal filter 2
One example of the filter characteristic is to remove the normal vibration sound components FD1 and FD2 of the X-ray tube 40, so that the user can clearly hear the occurrence, growth and magnitude of the abnormal vibration.

FIG. 15 is a diagram for explaining the X-ray tube control unit according to the embodiment. FIG. 15A is a block diagram of the X-ray tube control unit 50A. In the figure, 55 is an X-ray tube driving unit, 56 is a high voltage generation unit, 57 is a filament current control unit, 40 is an X-ray tube, 45 is a rotating anode, 43 is a cathode, 42
Reference numerals a and 42b denote two filaments, and 58 denotes a filament switch.

For example, when the filament 42a is heated,
Thermal electrons are generated, and a tube current mA corresponding to the tube voltage kV flows. When the filament current If is kept constant, at a certain tube voltage kV or higher, a substantially constant tube current mA flows regardless of the tube voltage kV. Since the tube current mA (filament current If) and the tube voltage kV can be independently adjusted in this region, the X-ray tube 40 is generally used in this region.

FIG. 15B is a front view of the filament (cathode). Two filaments 42a and 42b made of tungsten or the like are provided in parallel to the cathode portion 43. These filaments 42a and 42b are formed on the rotating anode 45 on the opposite surface regardless of which filament 42a / 42b is used. It is configured so that a line focus F can be formed. Normally,
For example, the filament 42a is used, and the filament 42a is used.
When a is consumed (cut), the filament 42b is used. Therefore, the life of the X-ray tube 40 caused by the filament can be substantially doubled.

FIG. 16 is a diagram showing the configuration of the X-ray CT apparatus monitoring system according to the embodiment, in which an abnormality in the X-ray tube 40 (vibration of the rotating anode 45,
This shows a case where monitoring data relating to the breaking of the filament 42) is collected at a central monitoring center and these are collectively monitored.

In the figure, 90 is a central monitoring center, 9
0₁~ 90_ThreeIs an X-ray CT installed at a remote hospital etc.
Apparatus, 200 is a monitoring center 90 and an X-ray CT apparatus 90₁~
90 _ThreeNetwork such as a public network or LAN connecting
(NW).

In the monitoring center 90, reference numeral 91 denotes a central processing unit which performs main control and processing (monitoring data collection control, monitoring processing of collected data, etc.) of the monitoring center 90, 91a its CPU, and 91b a main processing unit used by the CPU 91a. A memory (MEM) 92 is a device for inputting commands and data consisting of a keyboard, mass, and the like, and 93 is an X-ray CT device 90 _{1 to} 9.
0 ₃ 1 or 2 or more display device for monitor display of the monitoring data collected from (CRT), 94 a secondary storage device for storing collected data (disk), the 95 CPU 91
A common bus 98 a is a communication control unit (COM) connected to the network 200.

[0092] (vibration of the rotating anode 45, the cross-sectional like filament 42) each X-ray CT apparatus 90 _{1-90 3} of the X-ray tube 40 which is detected by the abnormality monitoring data according to via the communication control unit 17 of the respective It is sent to the central monitoring center 90. on the other hand,
In the monitoring center 90, a plurality of X-ray CT apparatuses 90 _{1 to} 90
_The monitoring data from ₃ is output to the display device 93, and these are monitored collectively. Note that the plurality of X-ray CT apparatuses 90 ₁ to 90 ₁ to
90 ₃ to collect audio data according to the abnormal sound of the X-ray tube 40 from which may be the operator of the monitoring center 90 listens.

The X-ray detection unit 60 and the vibration detection unit 60A of the types shown in FIGS. 3, 7, 8, and 10 are subjected to the abnormality detection method (frequency analysis) described in FIGS. It is obvious that a method based on the above method may be applied. Conversely, it is clear that the abnormality detection method (the extraction method using the high-pass filter 72) described in FIG. 3 may be applied to the vibration sensor 60 and the amplifier 60A described in FIG.

Although the above embodiment has been described with respect to an example of application to an X-ray CT apparatus, the present invention relates to various other apparatuses using a rotating anode type X-ray tube (X-ray television apparatus, industrial use). X-ray C
T device etc.).

Although the preferred embodiments of the present invention have been described above, it is needless to say that various changes can be made in the configuration, control, and combination of these components without departing from the spirit of the present invention. Not even.

[0096]

As described above, according to the present invention, since the abnormal state of the X-ray tube can be quantitatively and objectively grasped, the X-ray tube can be replaced at an appropriate timing, and the X-ray CT apparatus and the like can be replaced. The places that contribute to the improvement of reliability and operability are extremely large.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a main part configuration diagram of an X-ray CT apparatus according to an embodiment.

FIG. 3 is a diagram showing a configuration of an X-ray tube abnormality detection system according to the first embodiment.

FIG. 4 is a diagram (1) illustrating a vibration detection operation according to the first embodiment.

FIG. 5 is a diagram (2) illustrating a vibration detection operation according to the first embodiment.

FIG. 6 is a diagram (3) illustrating a vibration detection operation according to the first embodiment.

FIG. 7 is a diagram showing a configuration of an X-ray tube abnormality detection system according to a second embodiment.

FIG. 8 is a diagram showing a configuration of an X-ray tube abnormality detection system according to a third embodiment.

FIG. 9 is a diagram illustrating a vibration detection operation according to a third embodiment.

FIG. 10 is a diagram showing a configuration of an X-ray tube abnormality detection system according to a fourth embodiment.

FIG. 11 is a diagram showing a configuration of an X-ray tube abnormality detection system according to a fifth embodiment.

FIG. 12 is a diagram (1) showing a display mode of X-ray tube vibration monitoring data.

FIG. 13 is a diagram (2) showing a display mode of X-ray tube vibration monitoring data.

FIG. 14 is a diagram showing a configuration of an X-ray tube abnormality detection system according to a sixth embodiment.

FIG. 15 is a diagram illustrating an X-ray tube control unit according to the embodiment.

FIG. 16 is a diagram showing a configuration of an X-ray CT apparatus monitoring system according to an embodiment.

FIG. 17 is a diagram illustrating a conventional technique.

[Explanation of symbols]

 Reference Signs List 40 X-ray tube 42 Filament 43 Cathode 45 Rotating anode (slope) 60 Detection unit 60A Vibration detection unit 60B Abnormality detection unit 61 Slit plate 62 X-ray detection block 60A Vibration detection unit 71 Operational amplification unit 72 High-pass filter (HPF) 73, 76 Detector (DET) 74,77 A / D converter (A / D) 75 Low-pass filter (LPF) a, b, c, d X-ray detector

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Minoru Samata 127 Gee Yokogawa Medical System Co., Ltd., 4-7 Asahigaoka, Hino City, Tokyo (72) Inventor Daisuke Tanaka 4-7, Asahigaoka, Hino City, Tokyo 127 GE Yokogawa Medical System Co., Ltd. (72) Inventor Akira Izumihara 4-7-7 Asahigaoka, Hino-shi, Tokyo 127 GE GE Yokogawa Medical System Co., Ltd. 127 Gee Yokogawa Medical System Co., Ltd. (72) Inventor Hideto Masaura 4-7 Asahigaoka, Hino-shi, Tokyo 127 Gee Yokogawa Medical System Co., Ltd. F-term (reference) 4C092 AA01 AB30 AC01 AC17 BD07 BF04 BF10 DD01 4C093 AA22 BA10 CA36 CA38 CA50 E A02 EA03 EA14 EB17 EB18 EE01 FB12 FC16 FD04 FD05 FD11 FD13 FG05 FG19 FH06

Claims (11)

[Claims] 1. An X-ray tube abnormality detecting apparatus, wherein a cathode and a rotating anode having a slope with respect to the cathode face each other and generate X-rays by irradiating the slope with an electron beam spot. An X-ray tube comprising: a vibration detection unit that detects vibration of the X-ray tube; and an abnormality detection unit that detects an abnormal state of the X-ray tube based on an AC component of a predetermined band included in a detection signal of the vibration detection unit. Ball abnormality detection device. 2. A vibration detecting unit comprising two or more X-ray detecting elements for detecting X-rays incident through a slit, such that a dose received varies according to a movement of an X-ray source. 2. The X-ray tube abnormality detection apparatus according to claim 1, further comprising: an arrangement unit, and an operation amplification unit that forms and amplifies a difference signal of each X-ray detection element output. 3. The vibration detecting section comprises two or more X-ray detecting elements for detecting X-rays incident on a slope as a knife edge, wherein at least one X-ray detecting element is detected in accordance with the movement of the X-ray generating source. 2. The X-ray tube according to claim 1, further comprising: an X-ray tube arranged so that a dose received by the X-ray detector changes; and an operational amplifying unit that forms and amplifies a difference signal of each X-ray detection element output. Ball abnormality detection device. 4. The vibration detecting section opposes the X-ray tube with the subject interposed therebetween, and a number of X-ray detecting elements arranged in the channel direction are arranged in two or more rows in the body axis direction of the subject. An X-ray detector, a collimator interposed between the X-ray tube and the X-ray detector to limit the X-ray irradiation width in the body axis direction of the subject;
2. The operational amplifier according to claim 1, further comprising: an operational amplifier for forming and amplifying a difference signal of each X-ray detection output for two or more columns for a predetermined reference channel detection element on the X-ray detector. X-ray tube abnormality detector. 5. The X-ray detector according to claim 1, wherein the vibration detector includes an acceleration sensor fixed to the X-ray tube, and an amplifier that converts a detection output of the acceleration sensor into an electric signal. Abnormal detector for wire tube. 6. An abnormality detecting section including a filter for extracting an AC component in a predetermined band from a detection signal of the vibration detecting section, and detecting an abnormal state of the X-ray tube based on a signal amplitude of a filter output. The X-ray tube abnormality detection device according to claim 1. 7. An abnormality detection unit includes a frequency analysis unit that obtains a frequency component of a detection signal of the vibration detection unit, and determines an abnormal state of the X-ray tube based on a magnitude of a predetermined frequency component output from the frequency analysis unit. The X-ray tube abnormality detection apparatus according to claim 1, wherein the abnormality is detected. 8. A CT apparatus comprising a rotating anode type X-ray tube and an X-ray detector opposed to each other across a subject, and a CT tomographic image of the subject is reconstructed based on projection data collected from the X-ray detector. An X-ray CT apparatus comprising the X-ray tube abnormality detection apparatus according to any one of claims 1 to 7. 9. A thermo-electron is generated in an X-ray tube in which a cathode and a rotating anode having a slope with respect to the cathode face each other and emit X-rays by irradiating the slope with an electron beam spot. 2 of the same size and shape
An X-ray tube comprising: two filaments, one of which is connected to a common power supply and the other of which is configured to be switchable and capable of supplying power. 10. A rotating anode type X-ray tube and an X-ray detector opposed to each other across a subject, and a CT tomographic image of the subject is reconstructed based on projection data collected from the X-ray detector. An X-ray CT apparatus comprising the X-ray tube according to claim 9. 11. A plurality of X-ray CT apparatuses for transmitting monitoring data relating to vibration of the rotating anode detected for the own rotating anode type X-ray tube or disconnection of the filament, and a plurality of X-ray CT apparatuses via a network. Connect to each device and
A monitoring system for an X-ray tube, comprising: a central monitoring device that collects monitoring data from the X-ray CT apparatus and collectively monitors the operating state of the X-ray tube.