X-ray CT device

Abstract

To maintain a weight balance of a rotating part that holds a fuel cell generating water during power generation.SOLUTION: An X-ray CT device according to an embodiment includes a rotating part, a fuel cell, a tank, a drainage pipe, and a blade. The rotating part rotatably holds an X-ray tube. The fuel cell is provided in the rotating part. The tank is provided on an outer peripheral side of the rotating part relative to the fuel cell and has a substantially annular shape. The drainage pipe extends from the fuel cell to the tank. The blade has one end attached to an inner surface on the outer peripheral side of the tank, and the one end is positioned on a rotation direction side during scanning of the rotating part relative to the other end.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The embodiments disclosed in this specification and the drawings relate to an X-ray CT apparatus. [Background technology]

[0002] Conventionally, there is known an X-ray CT (computed tomography) device equipped with a CT gantry having a rotating part that holds an X-ray high voltage device. In this type of X-ray CT device, power supplied from a switchboard can be supplied to each unit of the rotating part via a slip ring even while the rotating part is rotating.

[0003] However, slip rings are expensive and need to be replaced periodically due to wear during use.In addition, the power supplied through the slip ring is alternating current (AC), so an AC / DC converter is required in front of the X-ray high voltage device in the rotating part.

[0004] In response to this, an X-ray CT device that does not require a slip ring and an AC / DC converter is being considered by mounting a rotating part that holds both a fuel cell using hydrogen energy and an X-ray high voltage device on the CT gantry. In this type of X-ray CT device, even while the rotating part is rotating, power can be supplied from the fuel cell to the X-ray high voltage device independently of the switchboard. In addition, since this X-ray CT device supplies power to the X-ray high voltage device from the fuel cell in the rotating part, a slip ring is not required. In this X-ray CT device, due to the characteristics of the fuel cell, water is generated when power is generated, so the generated water needs to be stored in the rotating part of the CT gantry. Specifically, for example, if 5 kg of hydrogen fuel is consumed as a result of power generation, 45 kg of generated water needs to be stored in the rotating part. For this reason, if power generation is continued, the weight of the rotating part of the CT gantry changes, and the weight balance is lost. As a result, after the rotation is stopped, when the rotation is started again for the next scan, etc., smooth rotation of the gantry cannot be performed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-10167 A Summary of the Invention [Problem to be solved by the invention]

[0006] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to maintain the weight balance of a rotating section that holds a fuel cell that generates water during power generation. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0007] The X-ray CT apparatus according to the embodiment includes a rotating unit, a fuel cell, a tank, a drain pipe, and a blade. The rotating unit rotatably holds an X-ray tube. The fuel cell is provided in the rotating unit. The tank is provided on the outer periphery side of the rotating unit relative to the fuel cell, and has a substantially annular shape. The drain pipe extends from the fuel cell to the tank. One end of the blade is attached to the inner surface on the outer periphery side of the tank, and the one end is located closer to the rotation direction of the rotating unit during scanning than the other end. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing the configuration of an X-ray CT apparatus according to the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram for explaining an example of the arrangement of the blades in the first embodiment, seen from the front of the gantry. [Diagram 3] FIG. 3 is a schematic diagram for explaining an example of the arrangement of the blades in the first embodiment, seen from the side of the gantry. [Figure 4] FIG. 4 is a schematic diagram for explaining the operation in the first embodiment. [Diagram 5]FIG. 5 is a schematic diagram for explaining the operation in the first embodiment. [Figure 6] FIG. 6 is a schematic diagram for explaining an example of the arrangement of the blade driving unit according to the second embodiment, viewed from the front of the gantry. [Figure 7] FIG. 7 is a schematic diagram for explaining the configuration of a blade driver according to the second embodiment. [Figure 8] FIG. 8 is a schematic diagram for explaining the configuration of a blade driver according to the second embodiment. [Figure 9] FIG. 9 is a schematic diagram for explaining the configuration of a blade driver according to a modified example of the second embodiment. [Figure 10] FIG. 10 is a schematic diagram for explaining the configuration of a blade driver according to a modified example of the second embodiment. [Figure 11] FIG. 11 is a block diagram showing the configuration of an X-ray CT apparatus according to the third embodiment. [Figure 12] FIG. 12 is a flowchart for explaining the operation in the third embodiment. [Figure 13] FIG. 13 is a schematic diagram for explaining the configuration of a water drop prevention mechanism according to the fourth embodiment. [Figure 14] FIG. 14 is a schematic diagram for explaining the configuration of a check valve according to the fifth embodiment. [Figure 15] FIG. 15 is a schematic diagram for explaining the configuration of a blade driver according to the fifth embodiment. [Figure 16] FIG. 16 is a schematic diagram for explaining an example of the arrangement of the FC stack in the sixth embodiment, seen from the front of the rack. [Figure 17] FIG. 17 is a schematic diagram for explaining an example of the arrangement of the FC stack in the sixth embodiment, seen from the side of the rack. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an X-ray CT apparatus according to each embodiment will be described with reference to the drawings. In the following description, the same reference numerals are used to designate substantially the same parts in different drawings, and redundant description will be omitted.

[0010] <First embodiment> 1 is a block diagram showing the configuration of an X-ray CT apparatus 1 according to one embodiment. The X-ray CT apparatus 1 irradiates an object P with X-rays from an X-ray tube 11, and detects the irradiated X-rays with an X-ray detector 12. The X-ray CT apparatus 1 generates a CT image of the object P based on an output from the X-ray detector 12.

[0011] The X-ray CT apparatus 1 shown in Fig. 1 includes a gantry device 10, a bed device 30, and a console device 40. The gantry device 10 is a scanning device having a configuration for performing X-ray CT imaging of a subject P. The bed device 30 is a device on which the subject P to be subjected to X-ray CT imaging is placed and which moves to a position where the X-ray CT imaging is performed. The console device 40 is a computer that controls the gantry device 10.

[0012] For example, the gantry device 10 and the bed device 30 are installed in a CT examination room, and the console device 40 is installed in a control room adjacent to the CT examination room. The console device 40 does not necessarily have to be installed in the control room. For example, the console device 40 may be installed in the same room as the gantry device 10 and the bed device 30. In any case, the gantry device 10, the bed device 30, and the console device 40 are connected to each other by wire or wirelessly so that they can communicate with each other.

[0013] The gantry 10 has an X-ray tube 11, an X-ray detector 12, a rotating frame 13, an X-ray high voltage device 14, a control device 15, a wedge 16, a collimator 17, and a DAS 18. The gantry 10 also has, as a fuel cell system, a hydrogen tank and an FC stack 21 arranged in a predetermined area 20, a rib / drain pipe 24, and a drain tank 25. The fuel cell system will be described later.

[0014] Here, the X-ray tube 11 is a vacuum tube that irradiates thermoelectrons from a cathode (filament) to an anode (target) by application of a high voltage and supply of a filament current from an X-ray high voltage device 14. The irradiated thermoelectrons are converted into X-rays by the energy generated when they collide with the focal point of the target. As a result, the X-ray tube 11 generates X-rays to be irradiated to the subject P from the focal point of the target where the thermoelectrons collide. The X-rays generated by the X-ray tube 11 are shaped into a cone beam via a collimator 17 and irradiated to the subject P.

[0015] The X-ray detector 12 detects X-rays irradiated from the X-ray tube 11 and passing through the subject P, and outputs an electrical signal corresponding to the amount of X-rays to the DAS 18. The X-ray detector 12 has, for example, a plurality of X-ray detection element rows in which a plurality of X-ray detection elements are arranged in the channel direction along one arc centered on the focal point of the X-ray tube. The X-ray detector 12 has, for example, a structure in which a plurality of X-ray detection element rows in which a plurality of X-ray detection elements are arranged in the channel direction are arranged in the slice direction (column direction, row direction). The X-ray detector 12 is an indirect conversion type detector having, for example, a grid, a scintillator array, and an optical sensor array. The scintillator array has a plurality of scintillators, and the scintillator has a scintillator crystal that outputs light with a photon amount corresponding to the amount of incident X-rays. The grid is arranged on the surface of the scintillator array on the X-ray incidence side, and has an X-ray shielding plate that has a function of absorbing scattered X-rays. The optical sensor array has a function of converting into an electrical signal corresponding to the amount of light from the scintillator, and has, for example, an optical sensor such as a photodiode. The X-ray detector 12 may be a direct conversion type detector (semiconductor detector) having a semiconductor element that converts incident X-rays into an electric signal.

[0016] The rotating frame 13 supports the X-ray tube 11 and the X-ray detector 12 so that they can rotate around a rotation axis. Specifically, the rotating frame 13 is an annular frame that supports the X-ray tube 11 and the X-ray detector 12 facing each other and rotates the X-ray tube 11 and the X-ray detector 12 by a control device 15 described later. The rotating frame 13 is rotatably supported by a fixed frame (not shown) made of a metal such as aluminum. More specifically, the rotating frame 13 is connected to an edge of the fixed frame via a bearing. In this embodiment, the rotation axis of the rotating frame 13 in a non-tilted state or the longitudinal direction of the tabletop 33 of the bed device 30 is defined as the Z-axis direction, the axial direction perpendicular to the Z-axis direction and horizontal to the floor surface is defined as the X-axis direction, and the axial direction perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. The rotating frame 13 rotates around the rotation axis Z at a constant angular velocity by receiving power from a drive mechanism of the control device 15. The rotating frame 13 further includes and supports the X-ray high voltage device 14 and the DAS 18 in addition to the X-ray tube 11 and the X-ray detector 12. The rotating frame 13 is housed in a substantially cylindrical housing in which an opening (bore) 19 that forms an imaging space is formed. The opening 19 substantially coincides with the FOV. The central axis of the opening 19 coincides with the rotation axis Z of the rotating frame 13. The rotation axis Z of the rotating frame 13 may be called the rotation axis Z of the X-ray tube 11. The detection data generated by the DAS 18 is transmitted, for example, from a circuit board 90 having a light-emitting diode (LED) to a data receiving device 91 having a photodiode provided in a non-rotating part (for example, a fixed frame) of the gantry by optical communication, and is then transferred to the console device 40. The method of transmitting the detection data from the rotating frame to the non-rotating part of the gantry is not limited to the optical communication described above, and any method of non-contact data transmission may be used. The rotating frame 13 is an example of a rotating part that rotatably holds the X-ray tube 11.

[0017] The X-ray high voltage device 14 has a high voltage generator having a function of generating a high voltage to be applied to the X-ray tube 11 and a filament current to be supplied to the X-ray tube 11 based on power supplied from a fuel cell (FC stack), and an X-ray control device that controls the output voltage according to the X-rays irradiated by the X-ray tube 11. The X-ray high voltage device 14 is provided on the rotating frame 13.

[0018] The control device 15 has a processing circuit having a CPU (Central Processing Unit) and the like, and a driving mechanism such as a motor and an actuator. The processing circuit has a processor such as a CPU or an MPU (Micro Processing Unit) and a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory) as hardware resources. The control device 15 controls the X-ray high voltage device 14 and the DAS 18, etc., according to a command from the console device 40. The processor, for example, realizes the above control by reading and implementing a program stored in the memory. For example, the processor may be configured by directly incorporating the above control function as a logic circuit in the circuit of the processor. The control device 15 also has a function of receiving an input signal from the console device 40 or an input interface attached to the gantry device 10 and controlling the operation of the gantry device 10 and the bed device 30. For example, the control device 15 receives an input signal and controls the rotation of the rotating frame 13, the tilt of the gantry device 10, and the operation of the bed device 30 and the tabletop 33. Moreover, the control device 15 may be provided in the gantry device 10 or in the console device 40 .

[0019] The wedge 16 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11. Specifically, the wedge 16 is a filter that transmits and attenuates the X-rays irradiated from the X-ray tube 11 so that the X-rays irradiated from the X-ray tube 11 to the subject P have a predetermined distribution. For example, the wedge 16 (wedge filter, bow-tie filter) is a filter made of processed aluminum so as to have a predetermined target angle and a predetermined thickness.

[0020] The collimator 17 is a lead plate or the like for narrowing down the irradiation range of the X-rays transmitted through the wedge 16, and a slit is formed by combining a plurality of lead plates or the like.

[0021] The DAS18 (Data Acquisition System) collects digital values ​​indicating the intensity of X-rays attenuated by the subject P for each view. The DAS18 has an amplifier that performs an amplification process on the electric signal output from each X-ray detection element of the X-ray detector 12, and an A / D converter that converts the amplified electric signal into a digital signal, and generates detection data having a digital value indicated by the digital signal. The detection data is a set of digital values ​​of X-ray intensity identified by the channel number and column number of the X-ray detection element that generated the data, and the view number indicating the collected view. As the view number, the order in which the views were collected (collection time) may be used, or a number indicating the rotation angle of the X-ray tube 11 (e.g., 1 to 1000) may be used. The detection data generated by the DAS18 is transferred to the console device 40 via a data receiving device 91 housed in the gantry device 10.

[0022] The bed device 30 is a device on which the subject P to be scanned is placed and moved, and includes a base 31, a bed driving device 32, a top board 33, and a support frame .

[0023] The base 31 is a housing that supports the support frame 34 so that the support frame 34 is movable in the vertical direction.

[0024] The bed driving device 32 is a motor or actuator that moves the tabletop 33 on which the subject P is placed in the longitudinal direction of the tabletop 33. The bed driving device 32 moves the tabletop 33 under the control of the console device 40 or the control of the control device 15. For example, the bed driving device 32 moves the tabletop 33 in a direction perpendicular to the subject P so that the body axis of the subject P placed on the tabletop 33 coincides with the central axis of the opening of the rotating frame 13. The bed driving device 32 may also move the tabletop 33 along the body axis direction of the subject P in accordance with X-ray CT imaging performed using the gantry device 10. The bed driving device 32 generates power by driving at a rotation speed according to the duty ratio of a drive signal from the control device 15. The bed driving device 32 is realized by a motor such as a direct drive motor or a servo motor.

[0025] The tabletop 33 provided on the upper surface of the support frame 34 is a plate on which the subject P is placed. The bed driving device 32 may move the support frame 34 in the longitudinal direction of the tabletop 33 in addition to the tabletop 33.

[0026] The console device 40 has a memory 41, a display 42, an input interface 43, and a processing circuit 44. Data communication between the memory 41, the display 42, the input interface 43, and the processing circuit 44 is performed via a bus.

[0027] The memory 41 is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or an integrated circuit storage device that stores various information. The memory 41 stores, for example, projection data and reconstructed image data. The memory 41 may be a drive device that reads and writes various information between a portable storage medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), or a flash memory, or a semiconductor memory element such as a RAM, in addition to an HDD or SSD. The storage area of ​​the memory 41 may be in the X-ray CT device 1 or in an external storage device connected via a network. For example, the memory 41 stores data of a CT image or a display image. The memory 41 also stores a control program according to this embodiment.

[0028] The display 42 displays various types of information. For example, the display 42 outputs medical images (CT images) generated by the processing circuitry 44, a GUI (Graphical User Interface) for receiving various operations from an operator, and the like. For example, as the display 42, a liquid crystal display (LCD), a cathode ray tube (CRT) display, an organic electroluminescence display (OLED), a plasma display, or any other arbitrary display can be used as appropriate.

[0029] The input interface 43 receives various input operations from an operator, converts the received input operations into electrical signals, and outputs the electrical signals to the processing circuitry 44. For example, the input interface 43 receives from the operator collection conditions for collecting projection data, reconstruction conditions for reconstructing a CT image, image processing conditions for generating a post-processed image from a CT image, and the like. As the input interface 43, for example, a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touchpad, a touch panel display, and the like can be used as appropriate. In this embodiment, the input interface 43 is not limited to one having physical operation parts such as a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touchpad, and a touch panel display. For example, an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs the electrical signal to the processing circuitry 44 is also included as an example of the input interface 43.

[0030] The processing circuitry 44 controls the operation of the entire X-ray CT apparatus 1 in response to an electrical signal of an input operation output from the input interface 43. For example, the processing circuitry 44 has a processor such as a CPU, MPU, or GPU (Graphics Processing Unit) and a memory such as a ROM or RAM as hardware resources. The processing circuitry 44 executes a system control function 441, a pre-processing function 442, a reconstruction processing function 443, an image processing function 444, a scan control function 445, a display control function 446, and the like, by a processor that executes a program expanded in the memory. Note that each of the functions 441 to 446 is not limited to being realized by a single processing circuit. A processing circuit may be configured by combining a plurality of independent processors, and each processor may execute a program to realize each of the functions 441 to 446. This also applies to each function added in each of the following embodiments.

[0031] The system control function 441 controls each function of the processing circuitry 44 based on an input operation received from an operator via the input interface 43. Specifically, the system control function 441 reads out a control program stored in the memory 41, expands it on the memory in the processing circuitry 44, and controls each part of the X-ray CT apparatus 1 according to the expanded control program. For example, the processing circuitry 44 controls each function of the processing circuitry 44 based on an input operation received from the operator via the input interface 43.

[0032] The pre-processing function 442 generates data by performing pre-processing such as logarithmic conversion processing, offset correction processing, inter-channel sensitivity correction processing, beam hardening correction, etc. on the detection data output from the data receiving device 91. Note that the data before pre-processing (detection data) and the data after pre-processing may be collectively referred to as projection data.

[0033] The reconstruction processing function 443 performs reconstruction processing using a filtered back projection method, an iterative reconstruction method, or the like on the projection data generated by the preprocessing function 442 to generate CT image data.

[0034] Based on an input operation received from an operator via the input interface 43, the image processing function 444 converts the CT image data generated by the reconstruction processing function 443 into tomographic image data of an arbitrary cross section or three-dimensional image data using a known method.

[0035] The scan control function 445 controls various operations related to X-ray scanning, such as supplying a high voltage to the X-ray high voltage device 14 and irradiating the X-ray tube 11 with X-rays. For example, the scan control function 445 acquires two-dimensional positioning image data of the subject P for determining the scan range, imaging conditions, and the like. Note that the positioning image data may also be called scano image data or scout image data. For example, after the scan by the rotating unit is completed, the scan control function 445 may rotate the rotating unit in a direction opposite to the rotation direction during the scan. The scan control function 445 is an example of a first control unit.

[0036] The display control function 446 controls the display 42 so as to display information on the process or results of processing by each of the functions 441-445.

[0037] 1 to 3, an example of the configuration of a fuel cell system provided on the gantry 10 will be described below. The fuel cell system is supported by a rotating frame 13 so as to be rotatable.

[0038] 2 and 3 are schematic diagrams for explaining an example of the arrangement of a hydrogen tank and FC stack 21, a rib / drain pipe 24, a drain tank 25, and a discharge mechanism 26 in a fuel cell system. Note that FC is an abbreviation for fuel cell. The FC stack is an example of a fuel cell provided in the rotating part.

[0039] Here, as shown in FIG. 2, the hydrogen tank and FC stack 21 are arranged in a predetermined region 20 of a substantially circular shape in the rotating part by the rotating frame 13, and the hydrogen tank for storing hydrogen and the FC stack for generating electricity by receiving hydrogen from the hydrogen tank are integrally provided. Furthermore, at least the hydrogen tank of the hydrogen tank and FC stack 21 has a shape that substantially coincides with the substantially circular shape of the predetermined region 20. In the example shown in FIG. 2, the FC stack of the hydrogen tank and FC stack 21 also has a shape that substantially coincides with the substantially circular shape of the predetermined region 20. Note that the predetermined region 20 is, for example, present on the inner periphery side of the rotating frame 13 and is positioned so as to surround the opening 19. The center of gravity of such a hydrogen tank and FC stack 21 substantially coincides with the center of rotation of the rotating part, and does not bias the rotation of the rotating part. Furthermore, as shown in FIG. 3, the position of the hydrogen tank and FC stack 21 in the axial direction of the rotating part is a position outside the path of the X-rays irradiated by the X-ray tube 11. In the example shown in Figure 3, two hydrogen tanks and FC stacks 21 are arranged, but this is not limited to the above, and the hydrogen tank and FC stack 21 may be arranged only on either the side closer to or the side farther from the bed device 30 in the axial direction of the rotating part.

[0040] The method of storing hydrogen in a hydrogen tank is, for example, a high-pressure hydrogen tank method in which gaseous hydrogen is compressed at high pressure and stored, but is not limited to this, and other methods such as a liquid hydrogen tank method in which liquid hydrogen is stored, or a hydrogen storage alloy method in which hydrogen is absorbed in a metal, can also be used.

[0041] The FC stack also converts hydrogen stored in the hydrogen tank into electrical energy, outputs a DC voltage to a boost converter (not shown), and sends water generated by power generation to the rib / drain pipe 24. For example, a polymer electrolyte fuel cell (PEFC) or the like can be used as the FC stack as appropriate. The boost converter boosts the voltage of the FC stack. That is, the boost converter boosts the DC voltage output from the FC stack and supplies it to the converter (not shown). Specifically, when the DC voltage output from the FC stack is lower than a desired voltage, the boost converter boosts the DC voltage. The converter converts the DC voltage received from the boost converter into an appropriate DC voltage and outputs it to an inverter (not shown). The inverter converts the DC voltage output from the converter into AC and supplies it to the X-ray high voltage device 14 described above. The FC stack may be called a power generation unit.

[0042] The rib-cum-drain pipe 24 extends from the predetermined area 20 to the drain tank 25 and is connected to the drain tank 25. The rib-cum-drain pipe 24 connects the FC stack in the hydrogen tank and FC stack 21 to the drain tank 25 and also serves as a rib that reinforces the rigidity of the rotating part. In detail, the rib-cum-drain pipe 24 extends linearly and radially so as to connect the FC stack in the hydrogen tank and FC stack 21 to the drain tank 25 in the shortest distance. That is, the rib-cum-drain pipe 24 discharges water generated during power generation in the FC stack in the hydrogen tank and FC stack 21 to the drain tank 25 by centrifugal force during rotation of the frame. However, the present invention is not limited to this, and the rib-cum-drain pipe 24 may be provided separately as a rib provided between the hydrogen tank and FC stack 21 and the drain tank 25 and a drain pipe extending from the predetermined area 20 to the drain tank 25. In the example shown in FIG. 2, four ribs-cum-drain pipes 24 are provided, but the present invention is not limited to this, and any number of ribs-cum-drain pipes 24 can be implemented. For example, one rib / drain pipe 24 and as many ribs as necessary to maintain rigidity may be provided.

[0043] The drainage tank 25 is formed in a substantially circular shape along the circumferential direction of the rotating part, and water generated in the hydrogen tank and FC stack 21 is discharged from the ribs and drain pipes 24. The drainage tank 25 holds water discharged when the rotating part rotates, and discharges the held water from a discharge mechanism 26 when the rotation stops. The drainage tank 25 is disposed on the circumferential side of the rotating part relative to the hydrogen tank and FC stack 21. The drainage tank 25 may also be called a water storage tank, since it stores water discharged from the ribs and drain pipes during rotation of the frame. The drainage tank 25 is an example of a substantially annular tank provided on the outer circumferential side of the rotating part relative to the fuel cell.

[0044] The discharge mechanism 26 is provided in the drain tank 25, and drains water from the drain tank 25 when the rotating part stops. The discharge mechanism 26 is, for example, a valve that opens and closes manually or automatically. In the case of the automatic operation, for example, the valve of the discharge mechanism 26 is controlled to be in an open state by a control signal received from the system control function 441 when the rotation stops. Similarly, the valve of the discharge mechanism 26 is controlled to be in a closed state by a control signal received from the system control function 441 when the rotation starts. In the case of the manual operation, for example, the valve of the discharge mechanism 26 is controlled to be opened and closed in response to the operation of the input interface 43. However, in the case of the manual operation, this is not limited to this, and the operator may directly open and close the valve of the discharge mechanism 26. For example, the discharge mechanism 26 is provided at a position that becomes the bottom of the drain tank 25 when the rotation of the rotating part stops, so that water accumulated at the bottom when the rotation stops can be discharged. The position that becomes the bottom of the drainage tank 25 when rotation stops is, for example, the position where a vertical line extending vertically downward from the X-ray tube 11 through the center of rotation of the rotating frame 13 intersects with the outer wall of the drainage tank 25 when the X-ray tube 11 is located at the top of the rotational orbit when rotation stops.

[0045] As shown in Figs. 2 to 4, one end 271 of the blade 27 is attached to the inner surface 25a on the outer periphery side of the drainage tank 25, and the one end 271 is located on the rotation direction rd side during scanning of the rotating part than the other end 272. The blade 27 holds the water wt pressed against the inner surface 25a on the outer periphery side of the drainage tank 25 by inertial force during scanning. Note that in Fig. 4, the height of the drainage tank 25 and the size of the blade 27 shown in Figs. 2 and 3 are exaggerated for ease of understanding. The blade 27 is a plate-like member provided on the inner surface 25a at a predetermined interval. As the blade 27, a material capable of holding water, such as metal or plastic, can be appropriately used. The explanation related to "during scanning" is not necessarily limited to during scanning, but also applies to rotation in the same rotation direction as during scanning (rotation before and after scanning).

[0046] Next, the operation of the X-ray CT device 1 configured as above will be described with reference to Figures 4 and 5. Note that, like Figure 4, Figure 5 also exaggerates the height of the drainage tank 25 and the size of the blade 27 shown in Figures 2 and 3 for ease of understanding.

[0047] First, when rotation starts, the hydrogen tank surrounding the opening 19 of the gantry 10 and the hydrogen tank in the FC stack 21 are filled with hydrogen, and the drainage tank 25 on the periphery is empty. Since the drainage tank 25 is empty, the weight balance of the rotating part is stable. Therefore, the gantry 10 can easily start rotating the rotating frame 13.

[0048] Next, while the rotating frame 13 is rotating, the hydrogen tank and the FC stack in the FC stack 21 generate electricity by chemically reacting hydrogen supplied from the hydrogen tank with oxygen in the air, and supply the electricity to each unit in the rotating section. Here, water generated during the chemical reaction is automatically discharged from the FC stack to the drain tank 25 through the rib / drain pipe 24 by the inertial force accompanying the rotation. At this time, as shown in FIG. 4, the discharged water wt is pressed against the inner surface 25a on the outer periphery side of the drain tank 25 by the inertial force and held by each blade 27, and is not biased in the drain tank 25, so the weight balance of the rotating section remains stable. In addition, the hydrogen tank and the hydrogen tank in the FC stack 21 become lighter in weight because hydrogen is consumed during the chemical reaction. However, since the hydrogen tank is located in the center of the rotating section and hydrogen, which is a gas, is evenly distributed in the hydrogen tank, the weight balance of the rotating section is not disturbed by the consumption of hydrogen.

[0049] Therefore, in the X-ray CT device 1, the rotating frame 13 can be rotated while maintaining the weight balance during power generation by the FC stack. Similarly, during scanning by the rotating part, the blades 27 hold the water pressed against the inner surface 25a on the outer periphery side of the drainage tank 25 by inertial force, so the weight balance of the rotating part is stable. Therefore, the X-ray CT device 1 can perform scanning (X-ray CT imaging) with the rotation of the rotating frame 13 stable.

[0050] When rotation is stopped, a portion of the water wt in the drainage tank 25 accumulates between the blade 27 and the inner surface 25a of the drainage tank 25, as shown in FIG.

[0051] In response to this, the processing circuitry 44 of the X-ray CT device 1 rotates the rotating part in a direction ird opposite to the rotation direction rd during scanning after the rotating part has finished scanning. Thus, when rotation stops, water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25 is drained and accumulates at the bottom of the drainage tank 25 by gravity. The water accumulated at the bottom is discharged from the drainage mechanism 26 to the outside of the drainage tank 25 by, for example, controlling the drainage mechanism 26 having a valve to an open state. This makes it possible to empty the drainage tank 25 and prepare for the start of the next rotation.

[0052] As described above, according to the first embodiment, the X-ray CT device 1 includes the rotating frame 13 as a rotating part, the FC stack 21 as a fuel cell, the drainage tank 25 as a substantially annular tank, the rib / drainage pipe 24 as a drainage pipe, and the blade 27. The rotating frame 13 rotatably holds the X-ray tube 11. The FC stack 21 is provided on the rotating frame 13. The drainage tank 25 is provided on the outer periphery side of the rotating frame 13 relative to the FC stack 21. The rib / drainage pipe 24 extends from the FC stack 21 to the drainage tank 25. One end 271 of the blade 27 is attached to an inner surface 25a on the outer periphery side of the drainage tank 25, and the one end 271 is located on the rotation direction rd side of the rotating part during scanning relative to the other end 272.

[0053] As a result, while the rotating frame 13 is rotating, the water wt generated in the FC stack 21 is automatically discharged from the FC stack 21 through the ribs / drain pipes 24 into the drainage tank 25 due to the inertial force associated with the rotation. Also, while the rotating frame 13 is rotating, the discharged water wt is held by the blades 27 while being pressed against the outer wall of the drainage tank 25 by the inertial force, so there is no uneven distribution within the drainage tank 25. This makes it possible to maintain the weight balance of the rotating part that holds the fuel cells that generate water during power generation. Also, it is possible to implement a drainage tank 25 that makes it easy to maintain the weight balance of the rotating part.

[0054] Furthermore, according to the configuration of the first embodiment, after the scanning by the rotating unit is completed, the processing circuit 44 rotates the rotating unit in the direction ird opposite to the rotation direction rd during the scan. Therefore, in addition to the above-mentioned effects, when the rotation is stopped, the water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25 can be discharged, and the discharged water wt can be accumulated at the bottom of the drainage tank 25 by gravity. Note that the water accumulated at the bottom is discharged from the discharge mechanism 26 to the outside of the drainage tank 25 by, for example, controlling the discharge mechanism 26 having a valve to an open state. This makes it possible to empty the drainage tank 25 and prepare for the start of the next rotation.

[0055] (Modification of the first embodiment) The first embodiment may be modified as follows. The modified examples may be combined with each other, or may be combined with the following embodiments.

[0056] As shown in Fig. 2, the hydrogen tank and FC stack 21 have a shape that roughly matches the roughly circular shape of the predetermined area 20, but this is not limited to this. For example, the hydrogen tank and FC stack 21 may be provided as a plurality of hydrogen tank sections and FC stack sections each having a roughly arc shape that is a division of the roughly circular shape of the predetermined area 20. According to this modification, in addition to the effect of the first embodiment, it is possible to implement a plurality of divided hydrogen tank sections and FC stack sections.

[0057] 3, two hydrogen tanks and two FC stacks 21 are arranged on either side of the X-ray path in the axial direction of the rotating part, but this is not limited to this. For example, the hydrogen tanks and the FC stacks 21 may be arranged only on one side, either closer to the bed device 30 or farther from it in the axial direction of the rotating part. Therefore, according to this modification, in addition to the effect of the first embodiment, it is possible to reduce the space required for the hydrogen tanks and the FC stacks 21.

[0058] As shown in FIG. 2, the rib-cum-drain pipe 24 extends linearly and radially so as to connect the predetermined area 20 to the circumferential side of the rotating part at the shortest distance, but is not limited thereto. For example, the rib-cum-drain pipe 24 may extend curvedly and radially between the FC stack and the drainage tank 25. Even with such a modified example, the same effect as that of the first embodiment can be obtained. Furthermore, according to this modified example, since there is no restriction that the rib-cum-drain pipe 24 connects the FC stack and the drainage tank 25 at the shortest distance, the degree of freedom of the layout in the rotating part can be increased. Moreover, this effect can be obtained in the same way even when a drainage pipe that does not also serve as a rib is used instead of the rib-cum-drain pipe 24.

[0059] <Second embodiment> The second embodiment is a modification of the first embodiment, and shows an example of a structure in which the blade 27 can be inserted into and removed from the drainage tank 25.

[0060] 6, the X-ray CT apparatus 1 according to the second embodiment includes a blade driving unit 28 that drives the blade 27 to move in and out of the drainage tank 25. Accordingly, the scan control function 445 of the processing circuitry 44 outputs a control signal for driving the blade 27 after the end of the scan by the rotating unit. The scan control function 445 is an example of a second control unit.

[0061] As shown in FIG. 7 and FIG. 8, the blade driving unit 28 drives the blade 27 along the direction ed connecting the other end 272 and the one end 271 based on a control signal received from the processing circuit 44. For example, the blade driving unit 28 includes a motor 281, a gear 282, and a plurality of rollers 283. The motor 281 generates a rotational driving force based on a control signal received from the processing circuit 44. The gear 282 transmits the rotational driving force of the motor 281 to a rack 273 formed on a part of the blade 27, thereby moving the blade 27 along the direction ed. The rack 273 may be called a toothed rod. The plurality of rollers 283 support the blade 27 so that it can move along the direction ed. Note that the magnitude of the angle θ1 between the inner surface 25a of the drain tank 25 and the blade 27 is constant before and after the movement of the blade 27. The roller 283 may be replaced with another member that supports the blade 27 so that it can slide along the direction ed, such as a guide plate or a groove.

[0062] The other configurations are similar to those of the first embodiment.

[0063] Next, the operation of the X-ray CT apparatus 1 configured as above will be described.

[0064] First, when rotation starts, the hydrogen tank 211 surrounding the opening 19 of the gantry 10 is filled with hydrogen, and the drainage tank 25 on the periphery is empty. Also, when rotation starts, each blade 27 is inserted into the drainage tank 25. Therefore, the gantry 10 can easily start rotating the rotating frame 13.

[0065] Next, during rotation of the rotating frame 13, including scanning, each blade 27 holds the water pressed against the inner surface 25a on the outer periphery of the drainage tank 25 by inertial force, as in the first embodiment, so that the weight balance of the rotating part is stable.

[0066] After the rotation unit finishes scanning, the processing circuitry 44 outputs a control signal to drive the blade 27.

[0067] 8, the blade driving unit 28 drives the blades 27 toward the outer periphery along the direction ed connecting the other end 272 and the one end 271 based on a control signal received from the processing circuit 44. Therefore, each blade 27 is brought out from the inside of the drainage tank 25 to the outer periphery.

[0068] Therefore, the water wt accumulated between the blades 27 and the inner surface 25a of the drainage tank 25 is discharged and accumulates at the bottom of the drainage tank 25 by gravity. The water accumulated at the bottom is discharged from the discharge mechanism 26 to the outside of the drainage tank 25, as described above. This empties the drainage tank 25, ready for the next start of rotation.

[0069] As described above, according to the second embodiment, the processing circuit 44 outputs a control signal to drive the blade 27 after the rotation unit finishes scanning. The blade drive unit 28 drives the blade 27 to the outer periphery along the direction ed connecting the other end 272 and the one end 271 based on the control signal. As a result, the blade 27 is drawn from the inside of the drainage tank 25 to the outer periphery, and the water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25 is discharged. Therefore, in addition to the above-mentioned effect, the water wt accumulated in the blade 27 can be discharged without rotating the rotation unit in the reverse direction ird.

[0070] (Modification of the second embodiment) The second embodiment may be modified as follows. The modified examples may be combined with each other, or may be combined with the following embodiments.

[0071] 6, the blade driving unit 28 is provided for each blade 27, and each blade 27 is driven individually, but this is not limiting. For example, one blade driving unit 28 may be provided for each blade 27, and all blades 27 may be driven simultaneously. This modification can achieve a simplified configuration in addition to the effects of the second embodiment.

[0072] Further, the blade driving unit 28 moves the blade 27 in and out of the drainage tank 25, but is not limited thereto. For example, the blade driving unit 28 may change the angle between the blade 27 and the drainage tank 25. Specifically, for example, as shown in FIG. 9 and FIG. 10, the blade driving unit 28 may drive the blade 27 around one end 271 of the blade so as to change the magnitude of the angle θ1 between the inner surface 25a of the drainage tank 25 and the blade 27 based on a control signal received from the processing circuit 44. For example, the blade driving unit 28 may include a motor 281 and a gear 282. The motor 281 generates a rotational driving force based on the control signal received from the processing circuit 44. The gear 282 transmits the rotational driving force of the motor 281 to a gear 273g formed on one end 271 of the blade 27, thereby rotating the blade 27 around the one end 271. In this case, the processing circuit 44 outputs a control signal for driving the blade 27 after the scanning by the rotating unit is completed. 9 and 10, the blade driving unit 28 drives the blade 27 around one end 271 of the blade so as to reduce the angle θ1 between the blade 27 and the inner surface 25a of the drainage tank 25 based on the control signal received after the end of the scan. This moves the blade 27 out from inside the drainage tank 25 to the outer periphery, thereby discharging the water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25. Even with this modified example, the same effect as in the second embodiment can be obtained.

[0073] <Third embodiment> The third embodiment is a modification of the second embodiment, and shows an example of a configuration for adjusting the extension and retraction of the blade in response to a decrease in the weight balance.

[0074] 11, the X-ray CT apparatus 1 according to the third embodiment includes a first sensor 51 for detecting the rotational vibration of the rotating part and a second sensor 52 for detecting the rotational speed of the rotating part. Accordingly, the processing circuitry 44 further realizes an abnormality detection function 447 and a blade control function 448.

[0075] Here, the first sensor 51 detects, for example, vibrations occurring in the lateral direction (X direction) and the front-rear direction (Z direction) of the gantry device 10 as rotational vibrations of the rotating frame 13. As the first sensor 51, for example, a vibration sensor can be appropriately used.

[0076] The second sensor 52 is, for example, a rotary encoder provided on a fixed portion that rotatably holds the rotating frame 13, and detects the rotation speed of the rotating frame 13 by generating a pulse signal with a frequency corresponding to the rotation speed of the rotating frame 13.

[0077] The abnormality detection function 447 of the processing circuit 44 detects a rotation abnormality of the rotating part during scanning. For example, the abnormality detection function 447 detects an abnormality in rotation vibration as a rotation abnormality based on the output of a first sensor that detects the rotation vibration of the rotating part. Also, for example, the abnormality detection function 447 detects an abnormality in rotation speed as a rotation abnormality based on the output of a second sensor that detects the rotation speed of the rotating part. The abnormality detection function 447 is an example of an abnormality detection unit.

[0078] The blade control function 448 of the processing circuit 44 controls the blade drive unit 28 to drive the blade 27 associated with the detected rotation abnormality, and causes the water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25 to flow. For example, the blade control function 448 identifies the blade 27 associated with the rotation abnormality based on the rotation angle of the rotating frame 13 at the time when the detected rotation abnormality occurred. Also, for example, the blade control function 448 estimates a position in the drainage tank 25 associated with the rotation abnormality based on the rotation angle, and identifies the blade 27 corresponding to the estimated position. The blade control function 448 is an example of a third control unit.

[0079] The other configuration is similar to that of the second embodiment.

[0080] Next, the operation of the X-ray CT apparatus 1 configured as above will be described with reference to the flowchart of FIG.

[0081] At the start of rotation, similarly to the second embodiment, the hydrogen tank 211 is filled with hydrogen and the outer peripheral water drainage tank 25 is empty. Also, at the start of rotation, each blade 27 is inserted into the water drainage tank 25. Therefore, the gantry 10 can easily start rotating the rotating frame 13.

[0082] Next, the X-ray CT apparatus 1 starts rotating the rotating frame 13 and sequentially executes steps ST1 to ST6.

[0083] In step ST1, the first sensor 51 detects the vibration occurring in the gantry device 10 as the rotational vibration of the rotating frame 13.

[0084] In step ST2, which is parallel to step ST1, the second sensor 52 detects the rotation speed of the rotating frame 13 by generating a pulse signal having a frequency corresponding to the rotation speed of the rotating frame 13. The processing circuit 44 detects the variation in the rotation speed detected by the second sensor 52 as rotation unevenness. For example, if the weight of the rotating part is biased, even if a scan control of 0.25 [s / 1 rotation] is performed, the rotation unevenness occurs, as 0.23 [s / 1 rotation] at one rotation position, 0.3 [s / 1 rotation] at another rotation position, and 0.25 [s / 1 rotation] at another position. In order to detect such rotation unevenness, the processing circuit 44 stores the rotation angle of the rotating frame 13 and the rotation speed of the rotating frame 13 in the memory 41 in association with each other. Thereafter, the processing circuit 44 detects, for example, the difference between the maximum value and the minimum value of the rotation speed during one rotation of the rotation angle as the rotation unevenness. However, without being limited thereto, the processing circuit 44 may detect, for example, the standard deviation or variance of the rotation speed during one rotation as the rotation unevenness.

[0085] After steps ST1 and ST2, in step ST3, the processing circuit 44 detects a rotation abnormality of the rotating part during scanning. For example, the processing circuit 44 determines whether the rotation vibration detected in step ST1 is equal to or greater than a threshold, and if it is equal to or greater than the threshold, detects the abnormality in the rotation vibration as a rotation abnormality and proceeds to step ST4. Also, for example, the processing circuit 44 determines whether the rotation unevenness detected in step ST2 is equal to or greater than a threshold, and if it is equal to or greater than the threshold, detects the abnormality in the rotation speed as a rotation abnormality and proceeds to step ST4. On the other hand, if the result of the determination in step ST3 is No, the process proceeds to step ST6.

[0086] After step ST3, in step ST4, the processing circuit 44 identifies the blade 27 associated with the rotation abnormality based on the rotation angle of the rotating frame 13 at the time when the detected rotation abnormality occurred. Specifically, for example, the processing circuit 44 estimates a position in the drainage tank 25 associated with the rotation abnormality based on the rotation angle, and identifies the blade 27 corresponding to the estimated position.

[0087] After step ST4, in step ST5, the processing circuit 44 controls the blade driving unit 28 to drive the blade 27 identified in relation to the rotation abnormality, and causes the water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25 to flow. As a result, as described above, while the rotating frame 13 is rotating, the blade 27 holds the water wt pressed against the outer periphery of the drainage tank 25 by inertial force, and the blade 27 is controlled to eliminate imbalance in the weight of the water wt, so that the weight balance of the rotating unit can be readjusted.

[0088] After step ST5, in step ST6, the processing circuit 44 judges whether the scan is over or not, and if the scan is not over, returns to step ST1 and repeats steps ST1 to ST5. Also, if the result of the judgment in step ST6 is that the scan is over, the processing circuit 44 ends the scan.

[0089] After the scan is completed, processing is carried out in the same manner as in the second embodiment.

[0090] As described above, according to the third embodiment, the processing circuitry 44 detects rotation abnormality of the rotating part during scanning. The processing circuitry 44 also controls the blade driving unit 28 to drive the blade 27 associated with the detected rotation abnormality, and causes the water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25 to flow. Therefore, in addition to the effects of the second embodiment, when a rotation abnormality is detected during scanning, the weight balance of the rotating part can be readjusted by the configuration that removes the water wt accumulated in the blade 27 associated with the rotation abnormality.

[0091] Furthermore, according to the third embodiment, the processing circuitry 44 identifies the blade 27 associated with the rotation abnormality based on the rotation angle of the rotating part at the time when the detected rotation abnormality occurred. Therefore, in addition to the above-mentioned effects, the blade 27 associated with the rotation abnormality can be easily identified.

[0092] Furthermore, according to the third embodiment, the processing circuit 44 estimates a position in the drainage tank 25 related to the rotation abnormality based on the rotation angle of the rotating part at the time when the rotation abnormality occurred, and identifies the blade 27 corresponding to the estimated position. Therefore, by estimating a position in the drainage tank 25 related to the rotation abnormality, the above-mentioned effects can be similarly obtained.

[0093] Furthermore, according to the third embodiment, the processing circuit 44 detects an abnormality in rotation vibration as a rotation abnormality based on the output of the first sensor 51 that detects the rotation vibration of the rotating part. This makes it possible to obtain the above-mentioned effects in a similar manner depending on the detection accuracy of the first sensor 51.

[0094] Furthermore, according to the third embodiment, the processing circuit 44 detects an abnormality in the rotation speed as a rotation abnormality based on the output of the second sensor 52 that detects the rotation speed of the rotating part. This makes it possible to obtain the above-mentioned effects in a similar manner depending on the detection accuracy of the second sensor 52.

[0095] <Fourth embodiment> The fourth embodiment is a modification of the second embodiment, and shows an example of a configuration in which a mechanism for preventing water from dropping is provided other than the blade 27. The fourth embodiment may be applied to the third embodiment.

[0096] The X-ray CT apparatus 1 according to the fourth embodiment includes a plurality of water drop prevention mechanisms 29 provided in the drainage tank 25 as shown in FIG.

[0097] Here, the water drop prevention mechanism 29 has one end 291 attached to the inner surface 25a on the outer periphery side of the drain tank 25, and the one end 291 is located on the opposite side of the rotation direction rd during scanning from the other end 292, and prevents the flow of water along the inner surface 25a. The water wt is discharged from the rib / drain pipe 24 (not shown) into the drain tank 25 during rotation of the rotating part, and reaches the inner surface 25a on the outer periphery side of the drain tank 25 from between the blade 27 and the water drop prevention mechanism 29 by centrifugal force. The angle θ2 between the inner surface 25a of the drain tank 25 and the water drop prevention mechanism 29 is an acute angle from the viewpoint of preventing the flow of water in the opposite direction to the rotation direction rd. However, from the viewpoint of facilitating the discharge of water after the end of scanning, it is preferable that the angle θ2 between the inner surface 25a and the water drop prevention mechanism 29 is larger than the angle θ1 between the inner surface 25a and the blade 27 (θ1<θ2<90 degrees). The water drop prevention mechanism 29 is an example of a flow prevention portion.

[0098] The other configuration is similar to that of the second embodiment.

[0099] Next, the operation of the X-ray CT apparatus 1 configured as above will be described.

[0100] The operation at the start of rotation is similar to that of the second embodiment.

[0101] Next, while the rotating frame 13 is rotating, including during scanning, the entrance for the water wt between the blades 27 and the water drop prevention mechanism 29 is narrowed as shown in Fig. 13, but the water wt enters through the narrow entrance due to the action of centrifugal force during rotation. In addition, the water pressed against the inner surface 25a on the outer periphery side of the drainage tank 25 by inertial force is held by each blade 27 and the water drop prevention mechanism 29, so the weight balance of the rotating part is stable. Even in the rotation position where water is most likely to fall, as shown on the left side of Fig. 13, the water drop prevention mechanism 29 can minimize the fall of the water wt traveling along the inner surface 25a.

[0102] After the scan is completed, the blade 27 is driven and the accumulated water wt is discharged in the same manner as described above.

[0103] As described above, according to the fourth embodiment, the water drop prevention mechanism 29 has one end 291 attached to the inner surface 25a on the outer periphery side of the drainage tank 25, and the one end 291 is located on the opposite side to the rotation direction rd during scanning than the other end 292, thereby preventing the flow of water along the inner surface 25a. Therefore, in addition to the effect of the second embodiment, it is possible to minimize the drop of water along the inner surface 25a even in the rotation position where water is most likely to drop.

[0104] <Fifth embodiment> The fifth embodiment is a modification of the fourth embodiment, and shows an example of a configuration in which a valve for preventing water from falling is provided at a water inlet / outlet between the water fall prevention mechanism 29 and the blade 27. The fifth embodiment may be applied to the third and fourth embodiments.

[0105] In the X-ray CT apparatus 1 according to the fifth embodiment, each blade 27 is provided with a check valve 274, as shown in FIG.

[0106] Here, the check valve 274 is provided for each blade 27, and allows the water wt to flow in one direction from the other end 272 of the blade 27 toward the one end 271 of the blade 27. A part of the check valve 274 abuts against the other end 292 of the water drop prevention mechanism 29 during scanning. Such a check valve 274 may include, for example, a substantially rectangular frame, a first valve rotatably provided on the edge of the frame on the blade 27 side, and a second valve rotatably provided on the edge of the frame on the water drop prevention mechanism 29 side. Since the first valve and the second valve abut against the other valve in a closed state, they only open in one direction from the other end 272 to the one end 271 of the blade 27. That is, the check valve 274 prevents the backflow of the water wt from a closed space surrounded by the blade 27, the inner surface 25a, the water drop prevention mechanism 29, and the check valve 274.

[0107] Accordingly, as shown in FIG. 15, after the scan is completed, the blade driving unit 28 drives the blade 27 toward the outer periphery based on a control signal received from the processing circuit 44, thereby moving the check valve 274 provided on the blade 27 away from the water drop prevention mechanism 29.

[0108] The other configuration is similar to that of the fourth embodiment.

[0109] Next, the operation of the X-ray CT apparatus 1 configured as above will be described.

[0110] The operation at the start of rotation is similar to that of the fourth embodiment.

[0111] Next, while the rotating frame 13 is rotating, including during scanning, water wt flows in through the check valve 274 due to the action of centrifugal force, as shown in Fig. 14. Also, the water pressed against the inner surface 25a on the outer periphery side of the drainage tank 25 by inertial force is held by each blade 27 and the water drop prevention mechanism 29, so the weight balance of the rotating part is stable. Even at the rotation position where water is most likely to fall, the check valve 274 can minimize direct water fall in addition to the water drop prevention mechanism 29 that minimizes the fall of water traveling along the inner surface 25a.

[0112] After the scan is completed, the blade driving unit 28 drives the blade 27 to the outer periphery based on the control signal received from the processing circuit 44, as shown in Fig. 15, to separate the check valve 274 provided on the blade 27 from the water drop prevention mechanism 29. This causes the accumulated water to be discharged in the same manner as described above.

[0113] As described above, according to the fifth embodiment, the blade 27 is provided with the check valve 274 that allows the water wt to flow in one direction from the other end 272 of the blade 27 toward the one end 271 of the blade 27. During scanning, a part of the check valve 274 abuts against the other end 292 of the water drop prevention mechanism 29. Therefore, in addition to the effect of the fourth embodiment, the check valve 274 can minimize direct water drop even in the rotation position where water is most likely to drop.

[0114] Furthermore, according to the fifth embodiment, after the scan is completed, the blade driving unit 28 drives the blade 27 to the outer periphery based on a control signal received from the processing circuit 44, and moves the check valve 274 provided on the blade 27 away from the water drop prevention mechanism 29. Therefore, in addition to the above-mentioned effects, it is possible to minimize the drop of water during the scan, while driving the blade after the scan is completed to drain the accumulated water.

[0115] Sixth embodiment The sixth embodiment is a modification of the first embodiment, and shows an example of a configuration in which the FC stack is provided at an appropriate location in the rotating part, instead of in a predetermined substantially circular region 20. The sixth embodiment may be applied to the second to fifth embodiments.

[0116] 16 and 17, the X-ray CT apparatus 1 according to the sixth embodiment includes a hydrogen tank 211, a hydrogen supply pipe 212, and an FC stack 213 instead of the hydrogen tank and the FC stack 21. The X-ray CT apparatus 1 also includes a drain pipe 241 instead of the rib / drain pipe 24.

[0117] Here, the hydrogen tank 211 is similar to that described above, and is provided in a predetermined, substantially circular region 20 within the rotating frame 13. Also, as shown in Fig. 17, the hydrogen tank 211 is arranged in the axial direction of the rotating part at a position outside the path of the X-rays irradiated by the X-ray tube 11. In the example shown in Fig. 17, two hydrogen tanks 211 and two hydrogen supply pipes 212 are arranged, but this is not limiting, and the hydrogen tank 211 and the hydrogen supply pipe 212 may be arranged only on either the side closer to or the side farther from the bed device 30 in the axial direction of the rotating part.

[0118] The hydrogen supply pipe 212 supplies hydrogen from the hydrogen tank 211 to the FC stack 213 .

[0119] The FC stack 213 is placed inside the rotating frame 13, and generates power by receiving hydrogen from the hydrogen tank 211 via a hydrogen supply pipe 212. The FC stack 213 is also provided at a position corresponding to a drain pipe 241, and discharges water generated during power generation into the drain pipe 241. Note that a weight to maintain weight balance may be placed at a position symmetrical to the FC stack 213 placed outside the predetermined area 20 across the rotation axis of the rotating frame 13.

[0120] The drain pipe 241 extends from the FC stack 213 to the circumferential side of the rotating part and is connected to the drain tank 25 .

[0121] As described above, one end 271 of the blade 27 is attached to the inner surface 25a on the outer periphery side of the drainage tank 25, and the one end 271 is located on the side of the other end 272 in the rotation direction rd during scanning of the rotating part.

[0122] The other configurations are similar to those of the first embodiment.

[0123] Next, the operation of the X-ray CT apparatus 1 configured as above will be described.

[0124] First, when rotation starts, the hydrogen tank 211 surrounding the opening 19 of the gantry 10 is filled with hydrogen, and the drain tank 25 on the periphery is empty. Therefore, the gantry 10 can easily start rotating the rotating frame 13.

[0125] Next, while the rotating frame 13 is rotating, the FC stack 213 generates electricity by chemically reacting hydrogen supplied from the hydrogen tank 211 with oxygen in the air, and supplies the electricity to each unit in the rotating section. Here, water generated during the chemical reaction is automatically discharged into the drainage tank 25 through the drain pipe 241 by the inertial force associated with the rotation. At this time, the discharged water is not unevenly distributed in the drainage tank 25 due to the inertial force and the blades 27, as described above, so the weight balance of the rotating section remains stable. Also, as described above, the hydrogen tank 211 is present in a predetermined area 20 that is approximately circular, and hydrogen is evenly distributed, so the weight balance of the rotating section is not disrupted by the consumption of hydrogen.

[0126] Therefore, in the X-ray CT device 1, the rotating frame 13 can be rotated while maintaining the weight balance during power generation by the FC stack. Similarly, during scanning by the rotating part, the blades 27 hold the water pressed against the inner surface 25a on the outer periphery side of the drainage tank 25 by inertial force, so the weight balance of the rotating part is stable. Therefore, the X-ray CT device 1 can perform scanning while the rotation of the rotating frame 13 is stable.

[0127] When the rotation stops, as described above, the rotating part is rotated in the opposite direction ird to the rotation direction rd during scanning, and the water wt accumulated between the blade 27 and the inner surface 25a of the drainage tank 25 is drained to the bottom of the drainage tank 25. Thereafter, the water accumulated at the bottom of the drainage tank 25 is drained from the drainage mechanism 26 to the outside of the drainage tank 25. This empties the drainage tank 25, ready for the start of the next rotation.

[0128] As described above, according to the sixth embodiment, even if the FC stack 213 is disposed in a position inside the rotating part other than the substantially circular predetermined area 20, it is possible to obtain the same effect as in the first embodiment. Specifically, for example, even if the FC stack 213 is provided in a position corresponding to the drain pipe 241 inside the rotating part, it is possible to obtain the same effect as in the first embodiment.

[0129] (Modification of the sixth embodiment) The sixth embodiment may be modified as follows. In addition, each modification may be combined with each other.

[0130] 16, hydrogen tank 211 has a shape that roughly corresponds to the roughly circular shape of predetermined area 20, but is not limited to this. For example, hydrogen tank 211 may be provided as a plurality of hydrogen tank sections each having a roughly arc shape that is formed by dividing the roughly circular shape of predetermined area 20. Each hydrogen tank section is connected to hydrogen supply pipe 212. According to this modification, in addition to the effect of the sixth embodiment, hydrogen tank 211 can be implemented as a plurality of divided hydrogen tank sections.

[0131] 17, two hydrogen tanks 211 are arranged on either side of the X-ray path in the axial direction of the rotating part, but this is not limited to this. For example, the hydrogen tank 211 and the hydrogen supply pipe 212 may be arranged only on either the side closer to the bed device 30 or the side farther from the bed device 30 in the axial direction of the rotating part. Therefore, according to this modification, in addition to the effect of the sixth embodiment, it is possible to save space for the hydrogen tank 211 and the hydrogen supply pipe 212.

[0132] According to at least one of the embodiments described above, it is possible to maintain the weight balance of the rotating portion that holds the fuel cell that generates water during power generation.

[0133] The term "processor" used in the above description means a circuit such as a CPU, a GPU, an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). When the processor is, for example, a CPU, the processor realizes a function by reading and executing a program stored in a memory. On the other hand, when the processor is, for example, an ASIC, instead of storing a program in a memory, the function is directly incorporated as a logic circuit in the circuit of the processor. Note that each processor in this embodiment is not limited to being configured as a single circuit for each processor, and may be configured as a single processor by combining multiple independent circuits to realize its function. Furthermore, the multiple components in FIG. 1 may be integrated into a single processor to realize its function.

[0134] In addition, there are various types of X-ray CT devices, such as a Rotate / Rotate-Type (third generation CT) in which an X-ray tube and an X-ray detector rotate around a subject as a unit, and a Stationary / Rotate-Type (fourth generation CT) in which a large number of X-ray detection elements arrayed in a ring are fixed and only the X-ray tube rotates around a subject, and any of these types can be applied to each embodiment. In addition, each embodiment can be applied to a single-tube X-ray CT device, as well as a so-called multi-tube X-ray CT device in which multiple pairs of X-ray tubes and detectors are mounted on a rotating ring. In addition, each embodiment may be applied to an X-ray CT device that can scan a subject in both an upright and a lying position depending on the scan mode.

[0135] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as the scope and spirit of the invention. [Explanation of symbols]

[0136] 1 X-ray CT device 10 Mounting device 11 X-ray tube 12 X-ray detector 19 Aperture 20 Prescribed Area 21 Hydrogen tank and FC stack 211 Hydrogen Tank 212 Hydrogen supply pipe 213 FC Stack 24 Rib-cum-drain pipe 241 Drain pipe 25 Drainage tank 26 Ejection mechanism 27 Blade 271,291 one end 272,292 other end 273 LACK 274 Check valve 28 Blade drive unit 29 Water fall prevention mechanism 41 Memory 42 Display 43 Input Interface 44 Processing Circuit 441 System Control Functions 442 Pre-processing function 443 Reconstruction Processing Function 444 Image Processing Function 445 Scan Control Function 446 Display Control Function 447 Anomaly Detection Function 448 Blade Control Function rd Rotation direction ird reverse direction ed direction Angle between θ1 and θ2

Claims

1. a rotating part that rotatably holds the X-ray tube; A fuel cell provided in the rotating part; a substantially annular tank provided on an outer circumferential side of the rotating part relative to the fuel cell; a drain pipe extending from the fuel cell to the tank; a blade having one end attached to an inner surface on the outer circumferential side of the tank, the one end being positioned closer to the rotation direction of the rotating part during scanning than the other end; An X-ray CT apparatus comprising:

2. a first control unit that rotates the rotation unit in a direction opposite to a direction of rotation during the scan after the scan by the rotation unit is completed; The X-ray CT apparatus according to claim 1 , further comprising:

3. a second control unit that outputs a control signal for driving the blade after the scanning by the rotation unit is completed; a blade driving unit configured to drive the blade toward the outer periphery along a direction connecting the other end and the one end based on the control signal; The X-ray CT apparatus according to claim 1 , further comprising:

4. a second control unit that outputs a control signal for driving the blade after the scanning by the rotation unit is completed; a blade driving unit that drives the blade around the one end so as to change the angle between the inner surface of the tank and the blade based on the control signal; The X-ray CT apparatus according to claim 1 , further comprising:

5. an abnormality detection unit that detects a rotation abnormality of the rotating unit during the scan; a third control unit that controls the blade driving unit to drive the blade associated with the detected rotation abnormality and causes water accumulated between the blade and the inner surface of the tank to flow; The X-ray CT apparatus according to claim 3 or 4, further comprising:

6. The third control unit identifies the blade associated with the rotation abnormality based on a rotation angle of the rotating unit at a time point when the detected rotation abnormality occurred. The X-ray CT apparatus according to claim 5 , further comprising:

7. The third control unit estimates a position in the tank related to the rotation abnormality based on the rotation angle, and identifies the blade corresponding to the estimated position. The X-ray CT apparatus according to claim 6 , further comprising:

8. The X-ray CT apparatus according to claim 5 , wherein the abnormality detection section detects an abnormality in the rotational vibration as the rotation abnormality based on an output of a first sensor that detects the rotational vibration of the rotating section.

9. The X-ray CT apparatus according to claim 5 , wherein the abnormality detection section detects an abnormality in the rotation speed as the rotation abnormality based on an output of a second sensor that detects a rotation speed of the rotating section.

10. a flow prevention part having one end attached to the inner surface on the outer circumferential side of the tank, the one end being located on the opposite side to the rotation direction during the scan than the other end, and preventing the flow of water along the inner surface; The X-ray CT apparatus according to claim 3 , further comprising:

11. the blade includes a check valve that allows water to flow in one direction from the other end of the blade toward the one end of the blade, During the scan, a portion of the check valve abuts against the other end of the flow prevention portion. The X-ray CT apparatus according to claim 10.

12. the blade driving unit drives the blade toward the outer periphery based on the control signal after the scan is completed, to separate the check valve provided in the blade from the flow prevention unit. The X-ray CT apparatus according to claim 11.

Images