JP5917106B2 - X-ray computed tomography apparatus and brush replacement timing output method - Google Patents

Description

  Embodiments described herein relate generally to an X-ray computed tomography apparatus having a slip ring mechanism.

  Conventionally, in order to supply electric power to a rotating unit, the X-ray computed tomography apparatus is provided with a slip ring at the rotating unit and a brush at the fixed unit. Electric power is supplied to the rotating part by bringing the slip ring and the brush into contact with each other. With continued use of the X-ray computed tomography apparatus, the brushes wear. When the brush is worn, the power transmission efficiency to the rotating part is reduced. In addition, brush wear can create a gap between the brush and the slip ring. The gap may cause a discharge. As a result, the stable supply of power to, for example, the X-ray tube in the rotating unit may be impaired. If the stable supply of power to the X-ray tube is impaired, the X-ray intensity may vary. Variations in x-ray intensity can cause artifacts.

  Conventionally, inspections and replacements regarding brush wear have been performed regularly. In addition, the inspection regarding the degree of wear of the brush (hereinafter referred to as the degree of wear) is performed by the visual inspection of the maintenance worker. The degree of wear varies depending on the operating conditions and usage of the X-ray computed tomography apparatus. For this reason, in regular inspection, there is a problem that the wear of the brush more than expected cannot be detected. In addition, the implementation of regular inspection work, despite the fact that there is little brush wear, is problematic in that it is inefficient and cost effective. From the above, there is a problem that this timing cannot be detected although it is necessary to perform maintenance such as brush replacement at an appropriate timing.

  The purpose is to detect the replacement time of the brush in the X-ray computed tomography apparatus.

The X-ray computed tomography apparatus according to the present embodiment includes an X-ray tube that generates X-rays, and is rotatably supported by a rotating frame, a driving unit that rotationally drives the rotating frame, and the rotating frame. A slip ring mechanism having a slip ring provided and a brush that contacts the slip ring, and a resistance value due to contact between the brush and the slip ring based on a rotational torque of the rotating frame generated by the drive unit A calculation unit that calculates the value, a warning output unit that outputs a predetermined warning when the calculated resistance value reaches a predetermined value, and a storage unit that stores a correspondence table of the amount of wear of the brush with respect to the resistance value; comprising a said warning output unit, based on said resistance value and the correspondence table to determine the amount of wear of the brush, the wear amount of the determined brush, the plants Outputting with the warning, characterized by.

FIG. 1 is a diagram illustrating a configuration of an X-ray computed tomography apparatus according to the first embodiment. FIG. 2 is a cross-sectional view showing a cross section of the rotating frame together with a slip ring attached to the rotating frame according to the first embodiment. FIG. 3 is a diagram illustrating an example in which the brush support portion is attached to the fixed portion according to the first embodiment. FIG. 4 is a diagram illustrating an example of a cross section of a brush that is in contact with a slip ring according to the first embodiment. FIG. 5 is a diagram illustrating an example of the configuration of the drive unit together with each unit related to the drive unit according to the first embodiment. FIG. 6 is a flowchart illustrating an example of a processing flow for displaying a predetermined warning when the sliding resistance calculated based on the rotational torque of the rotating frame reaches a predetermined value according to the first embodiment. is there. FIG. 7 is a diagram illustrating an example of a configuration of an X-ray computed tomography apparatus according to the second embodiment. FIG. 8 is a diagram illustrating an example of the configuration of an X-ray computed tomography apparatus according to the third embodiment. FIG. 9 is a graph illustrating an example of a correspondence table of the control angle θ with respect to the sliding resistance R according to the third embodiment. FIG. 10 is a flowchart illustrating an example of a flow of processing for calculating a resistance value based on the rotational torque of the rotating frame and controlling the brush support unit according to the third embodiment.

  Hereinafter, embodiments of an X-ray computed tomography apparatus (Computed Tomography) will be described with reference to the drawings. Note that in the X-ray computed tomography apparatus, an X-ray tube and an X-ray detector are integrated and a Rotate / Rotate-Type in which the periphery of the subject rotates and a large number of X-ray detection elements arrayed in a ring shape are fixed. There are various types such as Stationary / Rotate-Type in which only the X-ray tube rotates around the subject, and any type is applicable to the present embodiment. Further, in order to reconstruct an image, projection data for 360 ° around the subject and projection data for 180 ° + fan angle are required for the half scan method. The present embodiment can be applied to any reconfiguration method. In addition, the mechanism for changing incident X-rays to electric charge is based on an indirect conversion type in which X-rays are converted into light by a phosphor such as a scintillator and the light is further converted into electric charges by a photoelectric conversion element such as a photodiode, and by X-rays. The generation of electron-hole pairs in a semiconductor such as selenium and the transfer to the electrodes, that is, the direct conversion type utilizing a photoconductive phenomenon, are the mainstream. Any of these methods may be adopted as the X-ray detection element. Furthermore, in recent years, the so-called multi-tube type X-ray computed tomography apparatus in which a plurality of pairs of X-ray tubes and X-ray detectors are mounted on a rotating ring has been commercialized, and the development of peripheral technologies has progressed. Yes. In the present embodiment, either a conventional single-tube X-ray computed tomography apparatus or a multi-tube X-ray computed tomography apparatus can be applied. Here, a single tube type will be described.

  In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of an X-ray computed tomography apparatus according to the first embodiment.
The X-ray computed tomography apparatus 1 according to the first embodiment includes a high voltage generation unit 5, a gantry 7, a preprocessing unit 9, a reconstruction unit 11, an interface 13, a display unit 15, a calculation unit 17, a storage unit 19, An input unit 21, a control unit 23, and a warning output unit 25 are included.

  The high voltage generator 5 generates a high voltage to be supplied to the X-ray tube 71. In FIG. 1, the high voltage generator 5 is provided outside the gantry 7. The high voltage generator 5 may be mounted on a rotating frame 73 described later. Hereinafter, for convenience of explanation, it is assumed that the high voltage generator 5 is provided outside the gantry 7.

  The gantry 7 houses a rotation support mechanism. The rotation support mechanism includes a rotation frame 73, a frame support mechanism that supports the rotation frame 73 so as to be rotatable about the rotation axis Z, and a drive unit 79 that drives the rotation of the rotation frame 73. Mounted on the rotating frame 73 are an X-ray tube 71 and an area detector (hereinafter referred to as an X-ray detector 75) also called a two-dimensional array type or a multi-row type. The X-ray detector 75 faces the X-ray tube 71 with the imaging region 719 interposed therebetween. The X-ray tube 71 is electrically connected to the high voltage generator 5 via the slip ring mechanism 80. The slip ring mechanism 80 includes a slip ring 81 attached to the rotating frame 73 and a brush 82 disposed at a specific position on the outer periphery of the slip ring 81. The slip ring 81 is a ring-shaped conductive rail. The brush 82 is a conductive slider that contacts the surface of the slip ring 81. FIG. 2 is a view showing a cross section of the rotating frame 73 together with the slip ring 81.

  The brush 82 is supported by a brush support portion 83. The brush support portion 83 has an actuator not shown in FIG. The actuator drives the brush support portion 83 in order to separate the brush 82 from the slip ring 81 under the control of the control portion 23 described later. The actuator drives the brush support portion 83 to bring the brush 82 into contact with the slip ring 81 under the control of the control 23 described later. By the drive by the actuator, the brush support portion 83 supports the brush detachably with respect to the slip ring 81. The brush support portion 83 is provided in a fixed portion (not shown) in the gantry 7.

  FIG. 3 is a diagram illustrating an example in which the brush support portion 83 is attached to the fixed portion. As shown in FIG. 3, the brush support portion 83 is driven in the drive range (θ) by the actuator 84. By driving the brush support portion 83, the brush 82 is brought into contact with the slip ring 81 with a predetermined pressing force. Note that the brush support portion 83 may be installed directly on the fixed portion without using the actuator 84. At this time, the brush 83 is always in contact with the slip ring 81. The brush support portion 83 is not limited as shown in FIG. For example, instead of the actuator 84, a mechanism for separating the brush 82 from the slip ring 81 with the slip ring 81 and the brush 82 facing each other (hereinafter referred to as a facing separation mechanism) is provided between the brush support portion 83 and the fixed portion. It may be provided between them. FIG. 4 is a diagram illustrating an example of a brush in contact with a slip ring. The brush 82 may be provided on the rotating frame 73, and the slip ring 81 may be provided on the fixed portion.

  The drive unit 79 rotates the rotating frame 73 by direct drive or belt drive under the control of the control unit 23 described later. FIG. 5 is a diagram illustrating an example of the configuration of the drive unit 79 together with each unit related to the drive unit 79. The drive unit 79 includes a servo motor 791 and a servo amplifier 793. The servo motor 791 generates a rotational torque for rotating the rotating frame 73 using the current supplied from the servo amplifier 793. The generated rotational torque is transmitted to the rotating frame 73 via a direct drive or a belt drive. By this transmission, the servo motor 791 rotates the rotating frame 73. The servo motor 791 outputs a feedback pulse proportional to the rotation speed of the motor to the servo amplifier 793.

  The servo amplifier 793 controls the current supplied to the servo motor 791 based on a drive command output from the control unit 23 described later and a feedback pulse output from the servo motor 791. Specifically, the servo amplifier 793 changes the magnitude related to the sinusoidal current according to the electrical angle based on the drive command and the feedback pulse. By changing the magnitude of the current, the rotational torque changes. In this way, the servo amplifier 793 controls the servo motor 791. The servo amplifier 793 outputs the rotational torque of the rotating frame 73 to the calculation unit 17 described later based on the feedback pulse output from the servo motor 791.

  The X-ray tube 71 receives voltage application and current supply from the high voltage generator 5 via the slip ring mechanism 80 (brush 82 and slip ring 81). The X-ray tube 71 emits X-rays from an X-ray focal point 715 in response to application of voltage and supply of current. X-rays emitted from the X-ray focal point 715 are shaped into, for example, a cone beam shape (pyramidal shape) by a collimator unit attached to the X-ray emission window of the X-ray tube 71. The X-ray emission range is indicated by a dotted line 717. The X axis is a straight line that is orthogonal to the rotation axis Z and passes through the focal point 715 of the emitted X-ray. The Y axis is a straight line orthogonal to the X axis and the rotation axis Z. For convenience of explanation, the XYZ coordinate system will be described as a rotating coordinate system that rotates about the rotation axis Z.

  The X-ray detector 75 is attached at a position and an angle facing the X-ray tube 71 across the rotation axis Z. The X-ray detector 75 has a plurality of X-ray detection elements. Here, it is assumed that a single X-ray detection element constitutes a single channel. The plurality of channels are orthogonal to the rotation axis Z and centered on the focal point 715 of the emitted X-ray, and a circular arc direction having a radius from this center to the center of the light receiving portion of the X-ray detection element for one channel ( Channel direction) and Z direction are two-dimensionally arranged. Further, the X-ray detector 75 may be composed of a plurality of modules in which a plurality of X-ray detection elements are arranged in a line. Each module is arranged in a one-dimensional manner in a substantially arc direction along the channel direction.

  The plurality of X-ray detection elements may be two-dimensionally arranged in two directions, that is, a channel direction and a slice direction. That is, the two-dimensional arrangement is configured by arranging a plurality of channels arranged in a one-dimensional manner along the channel direction in a plurality of rows in the slice direction. The X-ray detector 75 having such a two-dimensional X-ray detection element array may be configured by arranging a plurality of the modules arranged in a one-dimensional shape in a substantially arc direction in a plurality of rows in the slice direction.

  During imaging or scanning, the subject P is placed on the top plate 31 and inserted into a cylindrical imaging region 719 between the X-ray tube 71 and the X-ray detector 75. A data acquisition circuit 77 called DAS (Data Acquisition System) is connected to the output side of the X-ray detector 75.

  The data acquisition circuit 77 includes an IV converter that converts a current signal of each channel of the X-ray detector 75 into a voltage, and an integration that periodically integrates the voltage signal in synchronization with an X-ray exposure cycle. A converter, an amplifier for amplifying the output signal of the integrator, and an analog / digital converter for converting the output signal of the amplifier into a digital signal are attached to each channel. Data (pure raw data) output from the data collection circuit 77 is transmitted to the preprocessing unit 9 via the non-contact data transmission unit 105 using magnetic transmission / reception or optical transmission / reception.

  The preprocessing unit 9 preprocesses the pure raw data output from the data collection circuit 77. The preprocessing includes, for example, sensitivity non-uniformity correction processing between channels, X-ray strong absorber, processing for correcting signal signal drop or signal loss due to extreme metal intensity mainly. Data immediately before reconstruction processing output from the pre-processing unit 9 (referred to as raw data or projection data, here referred to as projection data) is associated with data representing a view angle when data is collected. And stored in a storage unit 19 (to be described later) provided with a magnetic disk, a magneto-optical disk, or a semiconductor memory.

  The projection data is a set of data values corresponding to the intensity of X-rays that have passed through the subject. Here, for convenience of explanation, a set of projection data over all channels having the same view angle collected almost simultaneously in one shot is referred to as a projection data set. In addition, the view angle represents each position of the circular orbit around which the X-ray tube 71 circulates around the rotation axis Z as an angle in a range of 360 ° with the uppermost portion of the circular orbit vertically upward from the rotation axis Z as 0 °. It is a thing. The projection data for each channel in the projection data set is identified by the view angle, cone angle, and channel number. Further, the projection data for each channel of the projection data set may be identified according to the energy of the X-rays emitted from the X-ray tube 71.

  The reconstruction unit 11 reconstructs a substantially cylindrical three-dimensional image by the Feldkamp method or the cone beam reconstruction method based on a projection data set whose view angle is within a range of 360 ° or 180 ° + fan angle. It has a function. In the area at the end in the direction perpendicular to the slice plane (Z direction) in the volume data, there is an area where 360 ° projection data for reconstructing the field of view (Field of view) is not available. In areas where projection data is insufficient, the reliability of volume data is low. An area lacking projection data is not reconstructed or does not display a reconstructed image. This region is generally referred to as a mask (MASK) region. The Feldkamp method is a reconstruction method when a projection ray intersects the reconstruction surface like a cone beam. In the Feldkamp method, assuming that the cone angle is small, reconstruction is performed by regarding the cone beam as a fan projection beam when convolved, and reconstructing along the ray during scanning in back projection. This is an image reconstruction method. The cone beam reconstruction method is a reconstruction method that corrects projection data in accordance with the angle of the ray with respect to the reconstruction surface, as a method that suppresses cone angle errors more than the Feldkamp method.

  The interface 13 connects the X-ray computed tomography apparatus 1 to an electronic communication line (hereinafter referred to as a network). For example, at least one of a radiation department information management system (Radiology Information System: hereinafter referred to as RIS) and a hospital information system (Hospital Information System: hereinafter referred to as HIS) may be connected to the network.

  The display unit 15 displays medical images reconstructed by the reconstructing unit 11, conditions set for X-ray computed tomography, and the like.

  The calculation unit 17 calculates the resistance value of the brush 82 against the slip ring 81 (hereinafter referred to as sliding resistance R) using the rotational torque output from the servo amplifier 793 and the diameter D of the rotating frame. The rotational torque is a torque when the rotating frame 73 is rotated at a constant speed. The rotational torque includes a rotational torque when the brush 82 is in contact with the slip ring 81 (hereinafter referred to as contact rotational torque T1) and a rotational torque when the brush 82 is separated from the slip ring 81 (hereinafter referred to as separated rotation). There are two types of rotational torques, referred to as torque T2.

  The contact rotational torque T <b> 1 relates to the sliding resistance R of the brush and the frictional resistance due to the bearings provided on the rotating frame 73. The separation rotational torque T2 relates to the frictional resistance due to the bearing. The torque related to the sliding resistance R of the brush 82 is calculated by subtracting the separation rotation torque T2 from the contact rotation torque T1. Specifically, the calculation unit 17 calculates the sliding resistance R using, for example, the following expression using the contact rotation torque T1, the separation rotation torque T2, and the diameter D of the rotation frame 73.

R = 2 × (T1-T2) / D
Hereinafter, in order to describe a more accurate sliding resistance, the sliding resistance R is a value obtained by dividing twice the difference value obtained by subtracting the separated rotational torque T2 from the contact rotational torque T1 by the diameter D of the rotating frame 73. Define.

  The storage unit 19 stores medical images reconstructed by the reconstruction unit 11 (hereinafter referred to as reconstructed images). The storage unit 19 stores information such as an operator's instruction, image processing conditions, and shooting conditions input by the input unit 21 described later. The storage unit 19 stores the projection data output from the preprocessing unit 9. The storage unit 19 stores a control program for controlling the high voltage generation unit 5, the gantry 7, a bed unit (not shown), and the like for X-ray computed tomography. The storage unit 19 stores a predetermined value used in a warning output unit 25 described later. The predetermined value is, for example, the sliding resistance R related to the wear of the brush at the time of replacement of the brush 23.

  The input unit 21 inputs X-ray computed tomography imaging conditions desired by the operator, predetermined values, and the like. Specifically, the input unit 21 captures various instructions, commands, information, selections, and settings from the operator into the X-ray computed tomography apparatus 1. Although not shown, the input unit 21 includes a trackball, a switch button, a mouse, a keyboard, and the like for setting a region of interest. The input unit 21 detects the coordinates of the cursor displayed on the display screen, and outputs the detected coordinates to the control unit 23. The input unit 21 may be a touch panel provided to cover the display screen. In this case, the input unit 21 detects coordinates instructed by a touch reading principle such as an electromagnetic induction type, an electromagnetic distortion type, or a pressure sensitive type, and outputs the detected coordinates to the control unit 23. The input unit 21 can also input a predetermined value used in a warning output unit 25 described later.

  The control unit 23 functions as the center of the X-ray computed tomography apparatus 1. The control unit 23 includes a CPU (not shown). The control unit 23 controls the high voltage generation unit 5 and the gantry 7 for X-ray computed tomography based on the control program stored in the storage unit 19. The control unit 23 reads a control program for executing predetermined image generation / display and the like from a storage unit (not shown) and develops it on its own memory, and executes computations / processings and the like regarding various processes.

  The control unit 23 is a drive unit for rotating the rotating frame 73 at a constant speed in a state where the brush 82 is in contact with the slip ring 81 when power is supplied to the X-ray computed tomography apparatus 1. 79 is controlled. The supply of power to the X-ray computed tomography apparatus 1 means, for example, turning on the power of the X-ray computed tomography apparatus 1.

  The control unit 23 controls the actuator 84 provided in the brush support unit 83 in order to separate the brush 82 from the slip ring 81 in response to the output of the contact rotational torque T1 from the servo amplifier 793 to the calculation unit 17. Thereby, the brush 82 is separated from the slip ring 81. The control unit 23 controls the drive unit 79 to rotate the rotating frame 73 at a constant speed with the brush 82 separated from the slip ring 81. The control unit 23 controls the driving unit 79 to stop the rotation of the rotating frame 73 triggered by the output of the separated rotational torque T2 from the servo amplifier 793 to the calculating unit 19. The control unit 23 controls the actuator 84 to bring the brush 82 into contact with the slip ring 81 after the rotation frame 73 is stopped. In order to obtain the contact rotation torque T1 and the separation rotation torque T2, the control for rotating the rotation frame 73 at a constant speed is performed by an inspection other than when power is supplied to the X-ray computed tomography apparatus 1. It may be executed when there is no check or when all the inspections for the day are completed.

  The control unit 23 first controls the drive unit 79 to output the separated rotational torque T2 from the servo amplifier 793 to the calculation unit 17, and then outputs the contact rotational torque T1 from the servo amplifier 793 to the calculation unit 17. For this purpose, the drive unit 79 may be controlled.

  The warning output unit 25 includes at least one of a monitor and a speaker for outputting a warning. The warning output unit 25 determines whether or not the sliding resistance R calculated by the calculation unit 17 has reached a predetermined value. When the sliding resistance R reaches a predetermined value, the warning output unit 25 outputs a predetermined warning to at least one of the monitor and the speaker. The predetermined warning may be output to the display unit 15. The predetermined warning is, for example, a warning for prompting replacement or inspection of the brush. The monitor displays a display mode such as red display or blinking as a predetermined warning. The speaker generates a predetermined sound as a predetermined warning. The predetermined sound is, for example, a warning sound.

(Brush wear warning output function)
The brush wear warning output function is a function for outputting a predetermined warning when the sliding resistance R is lowered to a predetermined value due to wear of the brush 82. Hereinafter, processing related to the brush wear warning output function (hereinafter referred to as brush wear warning output processing) will be described.

  FIG. 6 is a flowchart showing an example of a process flow for outputting a predetermined warning when the sliding resistance R calculated based on the rotational torque of the rotating frame 73 reaches a predetermined value.

  When the X-ray computed tomography apparatus 1 is turned on, the rotating frame 73 is rotated at a constant speed by the drive unit 79 under the control of the control unit 23 (step Sa1). Due to the rotation of the rotating frame 73 at a constant speed, the contact rotation torque T1 and the separation rotation torque T2 are output from the servo amplifier 793 to the calculation unit 17. The sliding resistance R is calculated based on the contact rotational torque T1 and the separation rotational torque T2 (step Sa2). The calculated sliding resistance R is compared with a predetermined value stored in the storage unit 19 (step Sa3). If the sliding resistance R is less than a predetermined value, a predetermined warning is output (step Sa4).

(First modification)
The difference from the first embodiment is that the degree of wear of the brush is calculated based on the contact rotation torque T1 and the separation rotation torque T2.

  The calculation unit 17 calculates a torque related to the sliding resistance R (hereinafter referred to as a sliding torque) by subtracting the separated rotational torque T2 from the contact rotational torque T1. Immediately after the brush replacement, the calculation unit 17 subtracts the separated rotational torque T2 from the contact rotational torque T1. Thereby, the calculation part 17 calculates the torque regarding the sliding resistance R immediately after the brush replacement (hereinafter referred to as the sliding torque immediately after the replacement). The calculation unit 17 calculates a torque ratio obtained by dividing the sliding torque by the sliding torque immediately after replacement. The calculation unit 17 calculates the degree of brush wear obtained by subtracting the torque ratio from 1.

  The storage unit 19 stores a predetermined brush wear degree Bth. Note that the predetermined brush wear level can be input or changed via the input unit 21.

  The warning output unit 25 determines whether or not the brush wear degree calculated by the calculation unit 17 has reached a predetermined brush wear degree. When the brush wear level reaches a predetermined brush wear level, the warning output unit 25 outputs the brush wear level together with the predetermined warning to at least one of the monitor and the speaker.

(Second modification)
The difference between the first embodiment and the first modification is that the amount of brush wear is determined and output based on the sliding resistance R or the degree of brush wear. The brush wear amount is, for example, the amount or thickness of the brush worn by rotating the rotating frame 73 by bringing the brush 82 into contact with the slip ring 81. Specifically, for example, the brush wear amount is a reduction amount of the thickness of the brush 82. The brush wear amount may be the ratio of the brush thickness reduction amount to the brush thickness immediately after the brush is replaced. Further, instead of the amount of brush wear, the remaining amount of brush thickness as a result of wear of the brush thickness (hereinafter referred to as residual brush thickness) may be used. Instead of the remaining amount of brush thickness, the ratio of the remaining amount of brush thickness to the thickness of the brush immediately after replacing the brush (hereinafter, the remaining amount ratio) may be used.

  The calculation unit 17 calculates the sliding resistance R or the brush wear degree.

  The storage unit 19 stores a correspondence table of brush wear amounts with respect to the sliding resistance R (hereinafter referred to as a sliding wear correspondence table). Note that the remaining amount of brush thickness or the remaining amount ratio may be used instead of the brush wear amount. In addition, the memory | storage part 19 may memorize | store the correspondence table | surface of the brush wear amount with respect to a brush wear degree instead of a sliding wear correspondence table | surface.

  The warning output unit 25 determines the brush wear amount based on the sliding resistance R calculated by the calculation unit 17 and the sliding wear correspondence table stored in the storage unit 19. The determined brush wear amount is output from the warning output unit 25. The warning output unit 25 outputs the brush wear amount to the monitor or display unit 15 together with a predetermined warning. The warning output unit 25 may output the brush wear amount from a speaker together with a predetermined warning.

According to the configuration described above, the following effects can be obtained.
According to the X-ray computed tomography apparatus 1 in the present embodiment, a predetermined warning for prompting replacement or inspection of the brush 82 can be output based on the sliding resistance R of the brush 82 with respect to the slip ring 81. Further, according to the X-ray computed tomography apparatus 1, based on the sliding resistance R of the brush 82 with respect to the slip ring 81, the degree of wear and the amount of wear of the brush can be output together with a predetermined warning. Thereby, according to the X-ray computed tomography apparatus 1, it is possible to notify the operator of an appropriate timing for performing the inspection and replacement work of the slip ring 81 and the brush 82, and the efficiency of the inspection and replacement work is improved. In addition, the cost of the inspection and replacement work can be reduced, and the serviceability of the inspection and replacement work is improved. Furthermore, since inspection and replacement of the brush 82 can be performed at an appropriate timing, the quality related to power transmission via the slip ring mechanism 80 can be kept high.

(Second Embodiment)
The difference from the first embodiment is that a predetermined warning is output when the counted number of rotations reaches a predetermined number by counting the number of rotations of the rotating frame 73.

FIG. 7 is a diagram showing a configuration of the X-ray computed tomography apparatus 1 according to the second embodiment.
The X-ray computed tomography apparatus 1 further includes a counter 18 in addition to the components in the first embodiment.

  The counter 18 counts the number of rotations of the rotating frame 79 based on the feedback pulse output from the servo motor 791 to the servo amplifier 793 in the driving unit 79.

  The storage unit 19 further stores a predetermined rotational speed. The predetermined number of rotations is the number of rotations of the rotating frame 73 until the thickness of the brush 82 immediately after replacement is worn down to the thickness of the brush 82 at the time of replacement. That is, the predetermined rotation speed is rotation corresponding to the replacement time of the brush 82 when the brush 82 is worn.

  The warning output unit 25 compares the counted number of rotations with a predetermined number of rotations. When at least one of the fact that the counted number of rotations has reached a predetermined number of rotations and that the sliding resistance R has decreased to a predetermined value due to wear of the brush 82 is achieved, A predetermined warning is output to a monitor or a speaker.

(Brush wear warning output function)
The brush wear warning output function is a function for outputting a predetermined warning when the counted number of rotations reaches a predetermined number of rotations or when the sliding resistance R decreases to a predetermined value due to wear of the brush 82. is there. Hereinafter, processing related to the brush wear warning output function (hereinafter referred to as brush wear warning output processing) will be described.

  When the rotating frame 73 is rotated by the X-ray computed tomography apparatus 1, the number of rotations of the rotating frame 73 is counted by the counter 18. The counted number of rotations is compared with a predetermined number of rotations. When at least one of the counted number of rotations reaches a predetermined number of rotations and the sliding resistance R is decreased to a predetermined value due to wear of the brush 82, a predetermined warning is issued. The data is output from the output unit 25 to a monitor or a speaker.

(Third Modification)
The difference from the second embodiment is that the number of X-ray computed tomography examination reservations received from at least one of the RIS 200 and the HIS 201 connected to the X-ray computed tomography apparatus 1 via the network, or an input unit The number of rotations of the rotating frame 73 is determined based on the number of examination reservations for X-ray computed tomography input via 21. Next, a predetermined warning is output when the sum of the determined rotational speed and the rotational speed counted by the counter reaches a predetermined rotational speed.

  The RIS 200 is a computer system that efficiently works in the radiation department. Specifically, the RIS 200 is a computer system that performs inspection order reference to the radiation department, recording of inspection execution information, recording and transmission of accounting information, inventory management of consumables such as films, and various statistical processes. The number of examination reservations for X-ray computed tomography is input to the RIS 200 by a radiographer or the like based on an examination reservation table using the X-ray computed tomography apparatus 1.

  The HIS 201 refers to the entire computer system for efficiently performing operations in the hospital, and includes a medical accounting system, a test order system, a drug system, a meal system, a ward management system, and the like. The HIS 200 issues instructions for X-ray computed tomography based on a doctor's examination of the patient. X-ray computed tomography is performed based on the issued X-ray computed tomography instruction sheet. The RIS 200 and the HIS 201 store the number of examination reservations related to X-ray computed tomography. The number of examination reservations may be input via the input unit 21.

  The storage unit 19 receives and stores the number of examination reservations stored in the RIS 200 and the HIS 201 via the interface 13. The storage unit 19 may store the number of examination reservations input via the input unit 21. The storage unit 19 stores a correspondence table of the number of rotations of the rotation frame 73 with respect to the number of inspection reservations (hereinafter referred to as a reservation rotation number correspondence table).

  The calculation unit 17 determines the number of rotations of the rotating frame 73 (hereinafter referred to as the reserved number of rotations) based on the number of examination reservations stored in the storage unit 19 and the reserved number of rotations correspondence table. The calculation unit 17 calculates the sum of the determined reserved rotation speed and the rotation speed counted by the counter (hereinafter referred to as the total rotation speed).

  The warning output unit 25 compares the calculated total rotational speed with a predetermined rotational speed. When at least one of the fact that the counted number of rotations has reached a predetermined number of rotations and that the sliding resistance R has decreased to a predetermined value due to wear of the brush 82 is achieved, A predetermined warning is output to a monitor or a speaker.

According to the configuration described above, the following effects can be obtained.
According to the X-ray computed tomography apparatus 1 in the present embodiment, it is possible to output a predetermined warning for prompting replacement or inspection of the brush 82 based on the counted number of rotations of the rotating frame 73. Further, according to the X-ray computed tomography apparatus 1, it is possible to output a predetermined warning for prompting the replacement or inspection of the brush 82 based on the total rotational speed. As a result, according to the X-ray computed tomography apparatus 1, the operator can be informed of the appropriate timing for performing the inspection and replacement work of the slip ring 81 and the brush 82 before the brush wears. Increases efficiency. In addition, the cost of the inspection and replacement work can be reduced, and the serviceability of the inspection and replacement work is improved. Furthermore, since inspection and replacement of the brush 82 can be performed at an appropriate timing, the quality related to power transmission via the slip ring mechanism 80 can be kept high.

(Third embodiment)
The difference from the first and second embodiments is that the actuator 84 in the brush support portion 83 is controlled so that the sliding resistance R of the brush 82 relative to the slip ring 81 is positioned within a predetermined range.

FIG. 8 is a diagram showing a configuration of the X-ray computed tomography apparatus 1 according to the third embodiment.
The calculating unit 17 calculates the sliding resistance R by the process described in the first embodiment. The calculation unit 17 outputs the calculated sliding resistance R to the operation amount determination unit 27.

  The operation amount determination unit 27 determines the operation amount of the brush support unit based on the calculated resistance value. Specifically, the operation amount determination unit 27 generates a resistance angle correspondence table of angles (hereinafter referred to as control angles) with respect to the sliding resistance R smaller than the first threshold and the sliding resistance R larger than the second threshold. And stored in a memory (not shown). The control angle is an angle in the drive range of the actuator 84. A sliding resistance R smaller than the first threshold corresponds to a case where the force for pressing the brush 82 against the slip ring 81 (hereinafter referred to as pressing force) is smaller than the optimal pressing force. A sliding resistance R greater than the second threshold corresponds to a case where the pressing force is larger than the optimum pressing force. When the facing separation mechanism is provided between the brush support portion 83 and the fixed portion, the distance between the fixed portion and the brush support portion 83 is used instead of the control angle.

  FIG. 9 is a graph showing an example of a correspondence table of control angles with respect to the sliding resistance R. According to FIG. 9, the control angle is determined by the operation amount determination unit 27 according to the sliding resistance R.

  The operation amount determination unit 27 reads a resistance angle correspondence table stored in a memory (not shown). The operation amount determination unit 27 determines the control angle based on the sliding resistance R output from the calculation unit 17 and the resistance angle correspondence table read from the memory.

  The control unit 23 controls the actuator 84 in the brush support unit 83 so that the angle θ between the fixed unit and the brush support unit 83 becomes the determined control angle.

(Sliding resistance control function)
The sliding resistance control function determines the control angle based on the sliding resistance R calculated by the calculation unit 17 and the resistance angle correspondence table, and the actuator 84 in the brush support unit 83 so as to be the determined control angle. It is a function that controls. Hereinafter, processing relating to the sliding resistance control function (hereinafter referred to as sliding resistance control processing) will be described.

FIG. 10 is a flowchart illustrating an example of the flow of the sliding resistance control process.
The rotating frame 73 is rotated at a constant speed by the driving unit 79 under the control of the control unit 23 (step Sb1). Due to the rotation of the rotating frame 73 at a constant speed, the contact rotation torque T1 and the separation rotation torque T2 are output from the servo amplifier 793 to the calculation unit 17. The sliding resistance R is calculated based on the contact rotation torque T1 and the separation rotation torque T2 (step Sb2). The calculated sliding resistance R is compared with the first and second threshold values stored in the storage unit 19. (Step Sb3). When the sliding resistance R is not more than the first threshold and not less than the second threshold, the control angle is determined based on the sliding resistance R and the resistance angle correspondence table (step Sb4). The actuator 84 in the brush support portion 83 is controlled so as to achieve the determined control angle.

According to the configuration described above, the following effects can be obtained.
According to the X-ray computed tomography apparatus 1 in this embodiment, the control angle is determined based on the calculated sliding resistance R and the resistance angle correspondence table, and the brush support portion 83 is set to the determined control angle. The actuator 84 can be controlled. Thereby, according to the X-ray computed tomography apparatus 1, the pressing force of the brush 82 against the slip ring 81 can be optimized. From the above, since the pressing force of the brush 82 can be optimized, the quality related to the power transmission via the slip ring mechanism 80 can be kept high.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 1 ... X-ray computed tomography apparatus, 5 ... High voltage generation part, 7 ... Gantry, 11 ... Reconstruction part, 13 ... Interface, 15 ... Display part, 17 ... Calculation part, 18 ... Counter, 19 ... Memory | storage part, 21 DESCRIPTION OF SYMBOLS ... Input part, 23 ... Control part, 25 ... Warning output part, 27 ... Operation amount determination part, 31 ... Top plate, 71 ... X-ray tube, 73 ... Rotating ring, 75 ... X-ray detector, 77 ... Data acquisition circuit (DAS), 79 ... drive unit, 80 ... slip ring mechanism, 81 ... slip ring, 82 ... brush, 83 ... brush support unit, 84 ... actuator, 105 ... non-contact data transmission unit, 200 ... radiation department information management system ( RIS), 201 ... Hospital Information System (HIS), 715 ... X-ray focus, 717 ... X-ray emission range, 719 ... imaging area, 791 ... servo motor, 793 ... servo amplifier

Claims (9)

A rotating frame that carries an X-ray tube that generates X-rays and is rotatably supported;
A drive unit that rotationally drives the rotating frame;
A slip ring mechanism having a slip ring provided on the rotating frame and a brush in contact with the slip ring;
A calculation unit that calculates a resistance value due to contact between the brush and the slip ring based on a rotational torque of the rotating frame generated by the driving unit;
A warning output unit for outputting a predetermined warning when the calculated resistance value reaches a predetermined value ;
A storage unit for storing a correspondence table of the amount of wear of the brush with respect to the resistance value ,
The warning output unit determines the wear amount of the brush based on the resistance value and the correspondence table,
Outputting the determined amount of wear of the brush together with the predetermined warning ;
X-ray computed tomography apparatus. A rotating frame that carries an X-ray tube that generates X-rays and is rotatably supported;
A drive unit that rotationally drives the rotating frame;
A slip ring mechanism having a slip ring provided on the rotating frame and a brush in contact with the slip ring;
A calculation unit that calculates a resistance value due to contact between the brush and the slip ring based on a rotational torque of the rotating frame generated by the driving unit;
A warning output unit for outputting a predetermined warning when the calculated resistance value reaches a predetermined value;
A counter for counting the number of rotations of the rotating frame ;
An interface for receiving the number of examination reservations related to X-ray computed tomography executed by rotating the rotating frame from at least one of the radiation department information management system and the hospital information system via an electronic communication line; equipped with,
The calculation unit calculates the sum of the rotation number of the rotation frame corresponding to the inspection reservation number and the counted rotation number;
The warning output unit outputs the predetermined warning when the counted number of rotations reaches a predetermined number of rotations, and outputs the predetermined warning when the calculated sum reaches a predetermined number of rotations. Output ,
X-ray computed tomography apparatus. The warning output unit has a monitor for displaying the predetermined warning;
The X-ray computed tomography apparatus according to claim 1 or 2 . The warning output unit includes a speaker that generates a predetermined sound corresponding to the predetermined warning;
The X-ray computed tomography apparatus according to any one of claims 1 to 3 . Further comprising a brush support for removably supporting the brush with respect to the slip ring;
The calculator is
Calculating the resistance value based on a rotational torque of the rotating frame when the brush is separated from the slip ring and a rotating torque of the rotating frame when the brush is in contact with the slip ring. ,
X-ray computer tomography apparatus according to any one of claims 1 to 4, characterized in. The calculation unit calculates the degree of wear of the brush using the resistance value,
The warning output unit outputs the calculated degree of wear of the brush together with the predetermined warning;
The X-ray computed tomography apparatus according to any one of claims 1 to 5, wherein: A brush support part that removably supports the brush with respect to the slip ring;
An operation amount determination unit that determines an operation amount of the brush support unit based on the resistance value;
A control unit for controlling the brush support unit to operate the brush support unit over the determined operation amount;
X-ray computer tomography apparatus according to any one of claims 1 to 4, characterized in. Rotate a rotating frame equipped with an X-ray tube that generates X-rays,
Based on the rotational torque of the rotating frame, calculate a resistance value between a slip ring attached to the rotating frame and a brush brought into contact with the slip ring;
When the calculated resistance value reaches a predetermined value, a predetermined warning is output ,
Store a correspondence table of the amount of wear of the brush against the resistance value,
Based on the resistance value and the correspondence table, determine the amount of wear of the brush,
Outputting the determined amount of wear of the brush together with the predetermined warning ;
A brush replacement timing output method comprising:   Rotate a rotating frame equipped with an X-ray tube that generates X-rays,
  Based on the rotational torque of the rotating frame, calculate a resistance value between a slip ring attached to the rotating frame and a brush brought into contact with the slip ring;
When the calculated resistance value reaches a predetermined value, a predetermined warning is output,
  Count the number of rotations of the rotating frame,
  The number of examination reservations related to X-ray computed tomography performed by rotating the rotating frame is received from at least one of the radiation department information management system and the hospital information system via an electronic communication line,
  Calculating the sum of the number of rotations of the rotating frame corresponding to the number of inspection reservations and the counted number of rotations;
  Outputting the predetermined warning when the counted number of revolutions reaches a predetermined number of revolutions, and outputting the predetermined warning when the calculated sum reaches a predetermined number of revolutions;
  A brush replacement timing output method comprising:

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