EP-4736771-A1 - VIBRATION MEASUREMENT DEVICE FOR X-RAY COMPUTED TOMOGRAPHY DIAGNOSTIC DEVICE

EP4736771A1EP 4736771 A1EP4736771 A1EP 4736771A1EP-4736771-A1

Abstract

To provide a vibration measuring device of an X-ray computed tomography apparatus allowing for improved quality. A vibration measuring device (30) of an X-ray computed tomography apparatus, which includes a casing, a platform (13) configured to rotate in the casing, and an X-ray tube (15) arranged on the platform (13), is provided. A detector (33) configured to detect vibration in a state of the platform (13) rotating is arranged on at least one of the platform (13) and the X-ray tube (15).

Inventors

WATANABE Hazuo
MURAKOSHI YUUICHI

Assignees

Canon Electron Tubes & Devices Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240520

Claims (15)

A vibration measuring device of an X-ray computed tomography apparatus, the X-ray computed tomography apparatus including a casing, a platform configured to rotate in the casing, and an X-ray tube arranged on the platform, the vibration measuring device including; a detector arranged on either one or both of the platform and the X-ray tube, the detector configured to detect vibration in a state of the platform rotating.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 1, the X-ray computed tomography apparatus further including a cooling system arranged on the platform and configured to cool the X-ray tube, wherein the detector is arranged on at least one of the platform, the X-ray tube, and the cooling system.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 1, wherein when the detectors are to be arranged on the platform, each of the detectors is arranged at two positions on front and rear sides in an axial direction of a rotation axis of the platform.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 3, wherein each of the detectors is arranged at two positions where the X-ray tube is arranged on the platform, and each of the two positions is on front and rear sides in the axial direction of the platform with respect to the X-ray tube.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 1, wherein the detector detects vibration in a first state with the platform rotating and the X-ray tube and a cooling system having stopped operating, and in a second state with the platform rotating and the X-ray tube and the cooling system operating, respectively.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 1, wherein the detector is a three-dimensional accelerometer configured to detect vibration along respective directions of X, Y, and Z axes, and the X axis is oriented in a rotational direction of the platform, the Y axis is oriented in an axial direction of the platform, and the Z axis is oriented in a center direction of the platform.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 1 including a communication unit arranged on the platform and configured to wirelessly transmit detection data detected by the detector to an external destination.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 1 including a data logger configured to store chronologically detection data detected by the detector, in synchronization with rotation of the platform.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 8 including an acquisition unit configured to acquire the detection data detected by the detector, in synchronization with the rotation of the platform.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 9 including a display processing unit configured to graphically display chronological transition of the detection data acquired by the acquisition unit.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 10, wherein the detector is a three-dimensional accelerometer configured to detect vibration along respective directions of X, Y, and Z axes, and the X axis is oriented in a rotational direction of the platform, the Y axis is oriented in an axial direction of the platform, and the Z axis is oriented in a center direction of the platform, and the display processing unit displays, graphically in three dimensions, changes in vibration values detected by the detector along the respective directions of the X, Y, and Z axes.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 11, wherein the detector detects vibration in a first state with the platform rotating and the X-ray tube and a cooling system having stopped operating, and in a second state with the platform rotating and the X-ray tube and the cooling system operating, respectively, and the display processing unit displays, graphically in three dimensions, changes in the vibration values detected by the detector in the first state along the respective directions of the X, Y, and Z axes, and changes in the vibration values detected by the detector in the second state along the respective directions of the X, Y, and Z axes.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 10, wherein the display processing unit displays, chronologically and graphically in two dimensions, changes in vibration values detected by the detector.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 13, wherein the detector detects vibration in a first state with the platform rotating and the X-ray tube and a cooling system having stopped operating, and in a second state with the platform rotating and the X-ray tube and the cooling system operating, respectively, and the display processing unit displays, chronologically and graphically in two dimensions, changes in the vibration values detected by the detector in the first state, and changes in the vibration values detected by the detector in the second state.
The vibration measuring device of the X-ray computed tomography apparatus according to claim 10, wherein when the vibration value detected by the detector exceeds a predetermined threshold, the display processing unit displays a warning.

Description

Technical Field The embodiment according to the present invention relates to a vibration measuring device of an X-ray computed tomography apparatus. Background Art A general structural body has a natural resonant frequency. Due to the resonance phenomenon occurring within the resonant frequency range, large vibration and noise may be generated, leading to the damage of the structural body itself in some cases. In a computed tomography apparatus (hereinafter referred to as X-ray CT (computed tomography) apparatus), an X-ray tube and a cooling system, which have mass, are installed on a platform called gantry. The X-ray CT apparatus performs cross-sectional imaging of a test object by emitting X-rays while rotating the platform in a casing. In the X-ray CT apparatus, vibration is generated because the X-ray tube has an anode rotation mechanism part, the cooling system has a circulation pump for coolant circulation, and the platform itself rotates. In the X-ray CT apparatus in the prior art, since the expected output of the X-ray tube is small, the X-ray tube is compact, has low rigidity, and has a low mass. Therefore, the change in the vibration values caused by the operation of the X-ray tube has little impact on the X-ray CT apparatus as a whole. In recent years, with the higher performance of the X-ray CT apparatus, the expected output of the X-ray tube has been higher, and in response, the X-ray tube has increased in size, rigidity, and mass. Moreover, the platform has increased in rotation speed, and the change in the vibration values caused by the operation of the X-ray tube has increased. In general, the vibration frequency of a vibration source does not change, without deformation of the structural material or change in the rigidity of the vibration source. However, ninety-nine percent of the electric energy supplied to the X-ray tube for generating X-rays is converted into heat, and the heat causes deformation of the material and change in the rigidity of the anode part of the X-ray tube, resulting in change in resonant frequency. In the case where the change in resonant frequency leads to change in the vibration frequency generated by the vibration source, and thus interference with a resonant frequency of another structure occurs, resonance phenomena may occur, thereby leading to abnormal noise, the fluctuation in tube current caused by the vibration of the filament of the X-ray tube, damage over time, and the like. Citation List Patent Literature PTL 1: Japanese Laid-open Patent Publication No. 2020-13715 Summary of Invention Technical Problem The problem to be solved by the present invention is to provide a vibration measuring device of an X-ray computed tomography apparatus allowing for improved quality. Solution to Problem The present embodiment is a vibration measuring device of an X-ray computed tomography apparatus including a casing, a platform configured to rotate in the casing, and an X-ray tube installed on the platform, a detector, arranged on either one or both of the platform and the X-ray tube, and configured to detect vibration in a state of the platform rotating. Brief Description of Drawings [Fig. 1] Fig. 1 is a perspective view of an X-ray computed tomography apparatus in one embodiment.[Fig. 2] Fig. 2 is a cross-sectional view of a rotating part of the X-ray computed tomography apparatus, viewed from the front direction.[Fig. 3] Fig. 3 is a cross-sectional view of the rotating part of the X-ray computed tomography apparatus, viewed from the lateral direction.[Fig. 4] Fig. 4 is a block diagram of a vibration measuring device of the X-ray computed tomography apparatus.[Fig. 5] Fig. 5 shows examples of graphical displays of the measurement results obtained by the vibration measuring device: Fig. 5(A) is an explanatory diagram graphically displaying the chronological transition of the detection data synchronized with the rotation of a platform in the first state in which the X-ray tube is not emitting X-rays; and Fig. 5 (B) is an explanatory diagram graphically displaying the chronological transition of the detection data synchronized with the rotation of the platform in the second state in which the X-ray tube is emitting X-rays.[Fig. 6] Fig. 6 is a waveform diagram of the measurement result obtained by the vibration measuring device. Description of Embodiment Hereinafter, one embodiment will be described by referring to the drawings. Fig. 1 shows a perspective view of an X-ray computed tomography apparatus 10 (hereinafter, referred to as x-ray CT apparatus 10). The X-ray CT apparatus 10 includes a casing 11 serving as the outer enclosure of the X-ray CT apparatus 10. At the center of the casing 11, there is an introduction port 12 for introducing a test object. The X-ray CT apparatus 10 further includes a bed not illustrated, which allows a test object to be placed on it and facilitates introduction into the introduction port 12. Fig. 2 shows a cross-sectional view of a rotating p