JP7444752B2 - X-ray CT device - Google Patents

Description

The embodiments disclosed in this specification and the drawings relate to an X-ray CT apparatus.

2. Description of the Related Art In order to cool the inside of an X-ray CT (Computed Tomography) apparatus, there is a conventional technique in which a fan is provided on the cover of a gantry of the X-ray CT apparatus. However, if a fan is provided on the cover of the gantry device, there is a risk that a large amount of noise and vibration will be generated when the fan is operated. Alternatively, there is a technique in which fins are provided on a rotating body provided inside an X-ray CT apparatus. However, when the rotating body is provided with fins, heat cannot be exhausted from inside the X-ray CT when the rotating body is not rotating.

Japanese Patent Application Publication No. 2017-148157 Japanese Patent Application Publication No. 2002-65659

The problem to be solved by the embodiments disclosed in this specification and drawings is to make it possible to exhaust heat from inside the cover of the mount device even when the rotating body is not rotating, while suppressing the generation of large amounts of noise and vibration. It is to be. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems.

The X-ray CT apparatus according to the embodiment includes a cover, a rotating body, and a first fan. The cover is provided with an opening for inserting the subject. A rotating body is provided within the cover and rotates around the opening. The first fan exhausts air within the inner space of the cover to the outside of the cover. The first fan includes a first support and fins. The first support body is coaxial with the rotating body and is rotatable independently from the rotating body. A fin is provided on the first support.

FIG. 1 is a configuration diagram of an X-ray CT apparatus 1 according to a first embodiment. FIG. 2 is a diagram schematically showing a back view of the gantry device 10. FIG. FIG. 2 is a diagram schematically showing a side view of the gantry device 10. FIG. FIG. 2 is a diagram schematically showing a side view of the gantry device 10. FIG. FIG. 3 is a perspective view of the outer fan 100 seen from the back. FIG. 3 is a perspective view of the outer fan 100 seen from the front. 1 is a flowchart showing an example of the operation of the X-ray CT apparatus 1. A vector diagram of the analysis results of the first model. FIG. 3 is a diagram schematically showing a rear view of a gantry device 10 of an X-ray CT apparatus 2 according to a second embodiment. FIG. 2 is a diagram schematically showing a side view of the gantry device 10. FIG. FIG. 2 is a diagram schematically showing a side view of the gantry device 10. FIG. FIG. 3 is a perspective view of the front fan 200 viewed from the back. FIG. 3 is a perspective view of the front fan 200 viewed from the front. A vector diagram of the analysis results of the second model. FIG. 3 is a diagram schematically showing a rear view of main parts of an X-ray CT apparatus 3 according to a third embodiment. FIG. 4 is a diagram schematically showing a side view of main parts of an X-ray CT apparatus 4 according to a fourth embodiment.

Hereinafter, an X-ray CT apparatus according to an embodiment will be described with reference to the drawings. An X-ray CT apparatus is a medical device that includes a pedestal having an opening into which a subject can be inserted, and a bed having a top plate on which the subject is placed.

(First embodiment)
FIG. 1 is a configuration diagram of an X-ray CT apparatus 1 according to an embodiment, FIG. 2 is a diagram schematically showing a rear view of the gantry apparatus 10, and FIGS. 3 and 4 are schematic diagrams showing a side view of the gantry apparatus 10. 5A is a perspective view of the outer fan 100 seen from the front, and FIG. 5B is a perspective view of the outer fan 100 seen from the back. The X-ray CT apparatus 1 includes, for example, a gantry device 10, a bed device 30, and a console device 40. In FIG. 1, for convenience of explanation, both a view of the gantry apparatus 10 as viewed from the Z-axis direction and a view as seen from the X-axis direction are shown, but in reality, there is only one gantry apparatus 10. In the embodiment, the rotation axis of the rotation frame 17 in a non-tilted state or the longitudinal direction of the top plate 33 of the bed device 30 is in the Z-axis direction (back-and-forth direction), which is perpendicular to the Z-axis direction and horizontal to the floor surface. The axis is defined as the X-axis direction (eight circumferential directions), and the direction perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction (vertical direction). One side in the Z-axis direction, where the bed device 30 of the gantry device 10 is provided, is referred to as the "front side," and the other side in the Z-axis direction, the side opposite to the side where the bed device 30 is provided, is referred to as the "front side." One side in the X-axis direction is defined as the "left side," the other side is defined as the "right side," one side in the Y-axis direction is defined as the "upper side," and the other side is defined as the "lower side."

The gantry device 10 includes, for example, an X-ray tube 11, a wedge 12, a collimator 13, an X-ray high voltage device 14, an X-ray detector 15, and a data acquisition system (hereinafter referred to as DAS) 16. , a rotating frame 17, a motor 18, a bearing 19, a cover 20, and a control device 25. The cover 20 of the gantry device 10 further accommodates a clutch mechanism 70 and an outside fan 100. The X-ray tube 11, wedge 12, collimator 13, X-ray high voltage device 14, X-ray detector 15, DAS 16, rotating frame 17, motor 18, and bearing 19 are housed within the cover 20.

The X-ray tube 11 generates X-rays by irradiating thermoelectrons from a cathode (filament) toward an anode (target) by applying a high voltage from an X-ray high voltage device 14 . X-ray tube 11 includes a vacuum tube. For example, the X-ray tube 11 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

The wedge 12 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11 to the subject P. The wedge 12 attenuates the X-rays that pass through it so that the distribution of the amount of X-rays irradiated from the X-ray tube 11 to the subject P becomes a predetermined distribution. The wedge 12 is also called a wedge filter or a bow-tie filter. The wedge 12 is, for example, made of aluminum processed to have a predetermined target angle and a predetermined thickness.

The collimator 13 is a mechanism for narrowing down the irradiation range of the X-rays that have passed through the wedge 12. The collimator 13 narrows down the irradiation range of X-rays by forming a slit using a combination of a plurality of lead plates, for example. The collimator 13 is sometimes called an X-ray diaphragm. The narrowing range of the collimator 13 may be mechanically drivable.

The X-ray high voltage device 14 includes, for example, a high voltage generator and an X-ray control device. The high voltage generator has an electric circuit including a transformer, a rectifier, and the like, and generates a high voltage to be applied to the X-ray tube 11. The X-ray control device controls the output voltage of the high voltage generator according to the amount of X-rays to be generated in the X-ray tube 11. The high voltage generator may be one that boosts the voltage using the above-mentioned transformer, or may boost the voltage using an inverter. The X-ray high voltage device 14 may be provided on the rotating frame 17 or may be provided on the fixed frame (not shown) side of the gantry device 10.

The X-ray detector 15 detects the intensity of X-rays generated by the X-ray tube 11 and incident upon the subject P. The X-ray detector 15 outputs to the DAS 16 an electrical signal (an optical signal or the like) corresponding to the intensity of the detected X-rays. The X-ray detector 15 has, for example, a plurality of X-ray detection element rows. Each of the plurality of X-ray detection element rows has a plurality of X-ray detection elements arranged in the channel direction along an arc centered on the focal point of the X-ray tube 11. The plurality of X-ray detection element rows are arranged in the slice direction (column direction, row direction).

The X-ray detector 15 is, for example, an indirect detector having a grid, a scintillator array, and a photosensor array. A scintillator array has multiple scintillators. Each scintillator has a scintillator crystal. A scintillator crystal emits light in an amount corresponding to the intensity of incident X-rays. The grid is disposed on the surface of the scintillator array on which X-rays are incident, and has an X-ray shielding plate that has a function of absorbing scattered X-rays. Note that the grid is sometimes called a collimator (one-dimensional collimator or two-dimensional collimator). The optical sensor array includes optical sensors such as photomultiplier tubes (PMTs), for example. The optical sensor array outputs an electrical signal according to the amount of light emitted by the scintillator. The X-ray detector 15 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into electrical signals.

The DAS 16 includes, for example, an amplifier, an integrator, and an A/D converter. The amplifier performs amplification processing on the electrical signals output by each X-ray detection element of the X-ray detector 15. The integrator integrates the amplified electrical signal over a view period (described later). The A/D converter converts the electrical signal representing the integration result into a digital signal. DAS 16 outputs detection data based on digital signals to console device 40 . The detected data is a digital value of the x-ray intensity identified by the channel number of the generating x-ray detection element, the column number, and the view number indicating the collected view. The view number is a number that changes according to the rotation of the rotating frame 17, and is a number that is incremented according to the rotation of the rotating frame 17, for example. Therefore, the view number is information indicating the rotation angle of the X-ray tube 11. The view period is a period that falls between the rotation angle corresponding to a certain view number and the rotation angle corresponding to the next view number. The DAS 16 may detect the switching of views using a timing signal input from the control device 25, an internal timer, or a signal obtained from a sensor (not shown). . When performing a full scan and the X-ray tube 11 is continuously emitting X-rays, the DAS 16 collects a group of detection data for the entire circumference (360 degrees). When performing a half scan and the X-ray tube 11 is continuously emitting X-rays, the DAS 16 collects detection data for half the circumference (180 degrees).

The rotating frame 17 includes a first rotating frame 61 and a second rotating frame 62. The rotating frame 17 has a two-layer structure in which a second rotating frame 62 is disposed outside a first rotating frame 61. A clutch 70 mechanism is provided between the first rotating frame 61 and the second rotating frame 62. The first rotating frame 61 and the second rotating frame 62 are rotatable independently of each other when the clutch mechanism 70 disconnects them.

The first rotating frame 61 is an annular member that supports the X-ray tube 11, the wedge 12, the collimator 13, and the X-ray detector 15 so as to face each other. The first rotating frame 61 is rotatably supported by a fixed frame provided on the cover 20 via a bearing 19, centering on the subject P introduced therein. The first rotating frame 61 further supports the DAS 16. The detection data output by the DAS 16 is transmitted from a transmitter having a light emitting diode (LED) provided on the first rotating frame 61 to a photodiode provided on a non-rotating portion (for example, a fixed frame) of the gantry device 10 by optical communication. and is forwarded to the console device 40 by the receiver. Note that the method of transmitting the detection data from the first rotating frame 61 to the non-rotating portion is not limited to the method using optical communication described above, and any non-contact type transmitting method may be employed. The first rotating frame 61 is not limited to an annular member, but may be an arm-like member as long as it can support and rotate the X-ray tube 11 or the like. The first rotating frame 61 is an example of a rotating body.

The X-ray CT apparatus 1 is, for example, a Rotate/Rotate-Type X-ray CT apparatus (a third generation CT), but is not limited to this, and is not limited to Stationary/Rotate-Type, in which a plurality of X-ray detection elements arranged in an annular shape are fixed to a fixed frame, and the X-ray tube 11 rotates around the subject P. It may also be an X-ray CT device (4th generation CT).

Motor 18 is connected to outer fan 100, for example. The motor 18 is, for example, a DD (Direct drive) motor that directly transmits driving force to the outer fan 100 to be driven, without using an indirect mechanism such as a gear. The motor 18 operates based on a drive command output by the control device 25 and drives the outside fan 100. The motor 18 is an example of a drive unit. The drive unit may be a device other than a motor, and may be a member that provides power, such as a spring or a hydraulic cylinder.

The bearings 19 are interposed between the first rotating frame 61 and the cover 20 and between the second rotating frame 62 and the cover 20, respectively. The bearing 19 is attached to a fixed frame provided on the cover 20, for example, and rotatably supports the first rotating frame 61 and the second rotating frame 62 of the rotating frame 17, respectively.

The cover 20 is provided with a circular opening 21 for inserting the subject, and an internal space is formed inside the cover 20. As shown in FIG. 5A, an intake port 22 for introducing air into the cover 20 is formed on the back surface of the cover 20, and an exhaust port 22 for discharging air from the cover 20 is formed at the rear of the top surface of the cover 20. 23 is formed. The intake port 22 is provided at the lower part of the back surface of the cover 20. The exhaust port 23 is provided at the upper part of the rear part of the top surface of the cover 20. A rotating frame 17 is provided within the cover 20 and rotates around the circular opening 21.

The control device 25 includes, for example, a processing circuit including a processor such as a CPU (Central Processing Unit), and a drive mechanism including a motor, an actuator, and the like. The processing circuit realizes these functions by, for example, a hardware processor executing a program stored in a storage device (storage circuit).

Hardware processors include, for example, CPUs (Central Processing Units), GPUs (Graphics Processing Units), Application Specific Integrated Circuits (ASICs), and programmable logic devices (for example, Simple Programmable Logic Devices). Refers to a circuit such as a device (SPLD) or a complex programmable logic device (CPLD), or a field programmable gate array (FPGA).Instead of storing a program in a storage device, The program may be configured to be directly incorporated into the circuit of the hardware processor. In this case, the hardware processor realizes its functions by reading and executing the program incorporated within the circuit. It is not limited to being configured as a single circuit, but may be configured as a single hardware processor by combining multiple independent circuits to realize each function.Storage devices are non-temporary (hardware). Alternatively, multiple components may be integrated into one hardware processor to implement each function.

The control device 25 rotates the rotating frame 17, tilts the gantry device 10, and moves the top plate 33 of the bed device 30, for example. When tilting the gantry device 10, the control device 25 rotates the rotating frame 17 about an axis parallel to the Z-axis direction based on the tilt angle input to the input interface 43. The control device 25 knows the rotation angle of the rotating frame 17 based on the output of a sensor (not shown) or the like. Further, the control device 25 provides the rotation angle of the rotating frame 17 to the processing circuit 50 at any time. The control device 25 may be provided in the gantry device 10 or the console device 40.

The control device 25 causes the gantry device 10 to move on its own along the moving rail to perform main scan photography and scano photography which is positioning photography performed before execution of the main scan photography. The control device 25 controls the motor 18 and the clutch mechanism 70 by outputting drive commands (drive start command and drive end command) to the motor 18 and attachment and detachment commands (attachment command and detachment command) to the clutch mechanism 70, respectively. The control device 25 rotates only the rotating frame 17 during scanographic imaging, and rotates the rotating frame 17 during main scan imaging.

The clutch mechanism 70 is interposed between the first rotating frame 61 and the second rotating frame 62 within the cover 20 . The clutch mechanism 70 connects and connects the first rotating frame 61 and the second rotating frame 62 to integrate them, or connects the first rotating frame 61 and the second rotating frame 62 based on an attachment/detachment command output from the control device 25. The connection with the frame 62 may be severed.

As shown in FIG. 3, the state of the second rotating frame 62 in which it is disconnected from the first rotating frame 61 by the clutch mechanism 70 is referred to as an independent state. On the other hand, as shown in FIG. 4, the clutch mechanism 70 is connected to the first rotating frame 61 to make the first rotating frame 61 follow, and the state of the second rotating frame 62 rotating together with the first rotating frame 61 is changed to the cooperative state. That's what it means.

For example, when the independent second rotating frame 62 is rotated by the motor 18, the second rotating frame 62 rotates independently. On the other hand, when the motor 18 rotates the second rotating frame 62 in a co-operating state, the rotational force of the second rotating frame 62 is transmitted to the first rotating frame 61 via the clutch mechanism 70, and the second rotating frame 62 is rotated by the motor 18. The first rotating frame 61 rotates together with the rotating frame 62 . The clutch mechanism 70 switches the second rotating frame 62 between an independent state and a cooperative state. The control device 25 performs switching control to cause the clutch mechanism 70 to switch the second rotating frame 62 between an independent state and a cooperative state. The clutch mechanism 70 is an example of a switching mechanism.

The switching mechanism may be a mechanism other than the clutch mechanism 70. For example, two motors are provided to rotate the first rotating frame 61 and the second rotating frame 62, and a state in which only the second rotating frame 62 is rotated by the motor is an independent state, and the two motors are operated simultaneously and the first A state in which the second rotating frame 62 is rotated together with the rotating frame 61 may be referred to as a cooperative state. Alternatively, the switching mechanism has a transmission system that transmits the driving force of the motor 18, a transmission system that transmits the driving force only to the second rotating frame 62, and a transmission system that transmits the driving force to the first rotating frame 61 and the second rotating frame 62. It may also be a mechanism that switches the transmission system.

The second rotating frame 62 is arranged around the first rotating frame 61 within the cover 20 . The second rotating frame 62 includes three ring members arranged coaxially with the first rotating frame 61. The three ring members are arranged side by side in the front-rear direction. A plurality of outer fins 63 are provided upright on the outer peripheral surface of the second rotating frame 62 . The three ring members in the second rotating frame 62 are connected to the plurality of outer fins 63 and are degenerated.

The plurality of outer fins 63 are oriented in the same direction and are shaped to guide the air inside the cover 20 rearward when the second rotation frame 62 rotates in the first rotation direction. The second rotation frame 62 ventilates the inside of the cover 20 by rotating in a first rotation direction, for example, clockwise when viewed from the rear, and exhausts air in the internal space of the cover 20 to the outside of the cover 20 to exhaust heat. do.

The second rotation frame 62 is rotatable in the first rotation direction together with the first rotation frame 61. The second rotating frame 62 may be configured to be rotatable in a first reverse rotation direction that is opposite to the first rotation direction. The second rotating frame 62 is an example of a first support, the outer fan 100 is an example of a first fan, and the outer fin 63 is an example of a fin.

A back plate 64 is provided on the back side of the second rotating frame 62. The back plate 64 has a disc shape with a plurality of holes. A plurality of ventilation holes 65 are provided on the circumferential surface of the second rotating frame 62. The back plate 64 is provided with an inner opening 66 having approximately the same diameter as the circular opening 21 . The inner opening 66 is an opening into which the subject P is inserted. When the second rotation frame 62 rotates in the first rotation direction, the air inside the cover 20 is discharged to the outside in the circumferential direction of the second rotation frame 62 through the ventilation holes 65 by the suction force induced by the outer fins 63, and is guided forward. be done. When the second rotation frame 62 rotates in the first reverse rotation direction, the air within the cover 20 flows in the opposite direction to when the second rotation frame 62 rotates in the first rotation direction.

The bed device 30 is a device on which a subject P to be scanned is placed and moved, and introduced into the rotating frame 17 of the gantry device 10 . The base 31 of the bed device 30 includes a housing that supports a support frame 34 movably in the vertical direction (Y-axis direction). The bed driving device 32 includes a motor and an actuator. The bed driving device 32 moves the top plate 33 on which the subject P is placed along the support frame 34 in the longitudinal direction of the top plate 33 (Z-axis direction). The top plate 33 is a plate-shaped member on which the subject P is placed. The bed driving device 32 moves the top plate 33 backward and inserts it into the opening of the gantry device 10. The bed driving device 32 moves the top plate 33 forward and pulls it out from the gantry device 10.

The bed driving device 32 may move not only the top plate 33 but also the support frame 34 in the longitudinal direction of the top plate 33. Further, contrary to the above, the gantry device 10 may be movable in the Z-axis direction, and the rotating frame 17 may be controlled to come around the subject P by moving the gantry device 10. Alternatively, both the gantry device 10 and the top plate 33 may be movable.

The console device 40 includes, for example, a memory 41, a display 42, an input interface 43, and a processing circuit 50. In the embodiment, the console device 40 is described as being separate from the gantry device 10, but the gantry device 10 may include some or all of the components of the console device 40.

The memory 41 is realized by, for example, a RAM (Random Access Memory), a semiconductor memory element such as a flash memory, a hard disk, an optical disk, or the like. The memory 41 stores, for example, detection data, projection data, reconstructed image data, CT image data, and the like. These data may be stored not in the memory 41 (or in addition to the memory 41) but in an external memory with which the X-ray CT apparatus 1 can communicate. The external memory is controlled by a cloud server, for example, when the cloud server that manages the external memory accepts read/write requests.

The display 42 displays various information. For example, the display 42 displays a medical image (CT image) generated by a processing circuit, a GUI (Graphical User Interface) image, etc. that accepts various operations by an operator such as a doctor or a technician. The display 42 is, for example, a liquid crystal display, a CRT (Cathode Ray Tube), an organic EL (Electroluminescence) display, or the like. The display 42 may be provided on the gantry device 10. The display 42 may be of a desktop type, or may be a display device (for example, a tablet terminal) that can communicate wirelessly with the main body of the console device 40.

The input interface 43 accepts various input operations by an operator, and outputs an electrical signal indicating the content of the received input operation to the processing circuit 50. For example, the input interface 43 allows input operations such as acquisition conditions when collecting detection data or projection data, reconstruction conditions when reconstructing a CT image, and image processing conditions when generating a post-processed image from a CT image. accept. The input interface 43 is realized by, for example, a mouse, keyboard, touch panel, drag ball, switch, button, joystick, camera, infrared sensor, microphone, or the like. The input interface 43 may be realized by a display device (for example, a tablet terminal) that can communicate wirelessly with the main body of the console device 40.

Note that in this specification, the input interface is not limited to one that includes physical operation components such as a mouse and a keyboard. For example, examples of the input interface include 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 this electrical signal to a control circuit.

The processing circuit 50 controls the overall operation of the X-ray CT apparatus 1. The processing circuit 50 includes, for example, a control function 51, a preprocessing function 52, a reconstruction processing function 53, and an image processing function 54. The processing circuit 50 realizes these functions by, for example, a hardware processor executing a program stored in a storage device (storage circuit).

By hardware processor is meant a circuit such as, for example, a CPU, a GPU, an application specific integrated circuit, a programmable logic device or composite programmable logic device, a field programmable gate array, and the like. Instead of storing the program in the storage device, the program may be directly incorporated into the circuit of the hardware processor. The hardware processor is not limited to being configured as a single circuit, but may be configured as one hardware processor by combining a plurality of independent circuits to realize each function. The storage device may be a non-transitory (hardware) storage medium. Further, a plurality of components may be integrated into one hardware processor to realize each function.

Each component included in the console device 40 or the processing circuit 50 may be distributed and realized by a plurality of pieces of hardware. The processing circuit 50 may be realized by a processing device that can communicate with the console device 40 instead of the configuration that the console device 40 has. The processing device is, for example, a workstation connected to one X-ray CT device, or a device that is connected to multiple X-ray CT devices and collectively executes the same processing as the processing circuit 50 described below. For example, a cloud server).

The control function 51 controls various functions of the processing circuit 50 based on input operations received by the input interface 43. For example, the control function 51 executes processing for collecting detection data in the gantry device 10 by controlling the X-ray high voltage device 14, DAS 16, control device 25, and bed driving device 32.

The preprocessing function 52 performs preprocessing such as logarithmic conversion processing, offset correction processing, inter-channel sensitivity correction processing, and beam hardening correction on the detection data output by the DAS 16 to generate projection data. The projection data is stored in the memory 41.

The reconstruction processing function 53 performs reconstruction processing on the projection data generated by the preprocessing function 52 using a filtered back projection method, a successive approximation reconstruction method, etc., to generate CT image data. The CT image data is stored in the memory 41.

The image processing function 54 converts the CT image data into three-dimensional image data or cross-sectional image data of an arbitrary cross section using a known method based on the input operation received by the input interface 43. Conversion to three-dimensional image data may be performed by a preprocessing function 52.

Next, the operation of the X-ray CT apparatus 1 according to the first embodiment will be explained. FIG. 6 is a flowchart showing an example of the operation of the X-ray CT apparatus 1 according to the first embodiment. In FIG. 6, a procedure for capturing an X-ray image of the subject P through scanography and main radiography in the X-ray CT apparatus 1 will be described.

For example, when the operator inputs an imaging start switch provided on the input interface, the X-ray CT apparatus 1 starts imaging an X-ray image. When X-ray image capturing is started, the control device 25 first outputs a drive start command to the motor 18. At this time, since the outer fan 100 is in an independent state, the outer fan 100 begins to rotate independently by the rotation of the motor 18 (step S101).

When the outer fan 100 rotates, the air inside the cover 20 is sucked through the ventilation holes 65 by the outer fins 63 provided on the outer periphery of the outer fan 100 and guided to the exhaust port 23 provided at the rear of the top surface of the cover 20. Ru. Since the air inside the cover 20 is guided to the exhaust port 23, air is introduced into the cover 20 from the intake port 22 provided on the back surface of the cover 20, and the inside of the cover 20 is ventilated. Therefore, when the outside fan 100 starts rotating independently, ventilation inside the cover 20 is started while the rotating frame 17 is stopped.

Subsequently, the control device 25 performs scanography while keeping the outer fan 100 rotating (step S103). Since the outer fan 100 is rotating during scanography, the inside of the cover 20 is ventilated. By ventilating the inside of the cover 20, the heat inside the cover 20 is exhausted and the equipment inside the cover 20 is cooled.

When the scanography is completed, the control device 25 outputs a mounting command to the clutch mechanism 70, and causes the clutch mechanism 70 to bring the outer fan 100 into a cooperative state (step S105). When the outer fan 100 enters the cooperative state, the first rotating frame 61 rotates following the outer fan 100. The control device 25 executes main scan photography while rotating the first rotating frame 61 (step S107). Since the outer fan 100 continues to rotate while the main scan imaging is being performed, the heat inside the cover 20 is exhausted and the equipment inside the cover 20 is cooled.

When the main scan photographing is completed, the control device 25 outputs a disengagement command to the clutch mechanism 70 to disengage the first rotating frame 61 and the second rotating frame 62, thereby setting the outer fan 100 in an independent state (step S109). Since the outer fan 100 becomes independent, the outer fan 100 continues to rotate, but the first rotating frame 61 gradually decelerates and stops.

Subsequently, the control device 25 determines whether there is a next patient (step S111). If it is determined that there is a next patient, the control device 25 returns the process to step S103 and performs scanography again. If it is determined that there is no next patient, the control device 25 continues driving the motor 18 to maintain a state in which only the second rotating frame 62 (outside fan 100) is rotating (step S113).

Subsequently, the control device 25 determines whether a predetermined time has elapsed since the main scan imaging was completed (step S115). If it is determined that the predetermined time has not elapsed, the control device 25 returns the process to step S113 and continues to rotate only the outer fan 100 until the predetermined time has elapsed. If it is determined that the predetermined time has elapsed, the control device 25 outputs a drive end command to the motor 18, and ends the process shown in FIG. 6.

Next, a model (hereinafter referred to as "first model") in which the outer fan 100 in the X-ray CT apparatus 1 according to the first embodiment is rotated is created, and the air inside the cover 20 in the first model is The results of the flow analysis will be explained. FIG. 7 is a vector diagram of the analysis results of the first model.

From the analysis results shown in FIG. 7, when the outer fan 100 is rotated in the first rotation direction inside the cover 20 of the X-ray CT apparatus 1, the air flow inside the cover 20 is as shown below. First, air is introduced into the cover 20 from the air intake port 22 provided on the back surface of the cover 20. The air introduced into the cover 20 passes through the ventilation hole 65 provided in the outer fan 100 and is guided forward. Thereafter, the air within the cover 20 is exhausted to the outside of the cover 20 through the exhaust port 23.

In the X-ray CT apparatus 1 according to the first embodiment, by rotating the outer fan 100, the inside of the cover 20 can be ventilated, heat can be exhausted from the inside of the cover 20, and equipment inside the cover 20 can be cooled. . Since the outer fan 100 is disposed around the first rotating frame 61, there is no need to provide a fan on the cover 20, so that it is possible to suppress the generation of a large amount of noise and vibration.

Furthermore, in the X-ray CT apparatus 1 according to the first embodiment, a clutch mechanism 70 is provided between the first rotating frame 61 and the second rotating frame 62. Therefore, the outer fan 100 is rotatable independently of the first rotating frame 61. Therefore, even when the first rotating frame 61 is not rotating, the inside of the cover 20 can be ventilated and heat can be exhausted. Furthermore, the cooling effect can be adjusted by setting the rotation speed of the outer fan 100 and adjusting the air volume within the cover 20, regardless of the rotation speed of the first rotating frame 61. Therefore, the rotation speed of the outer fan 100 can be controlled based on the temperature inside the cover 20, for example.

(Second embodiment)
FIG. 8 is a diagram schematically showing a rear view of the gantry apparatus 10 in the X-ray CT apparatus 2 according to the second embodiment, and FIGS. 9 and 10 are diagrams schematically showing a side view of the gantry apparatus 10, FIG. 11B is a perspective view of the front fan 200 seen from the back, and FIG. 11B is a perspective view of the front fan 200 seen from the front. The X-ray CT apparatus 2 differs from the X-ray CT apparatus 1 according to the first embodiment mainly in that a front fan 200 is provided instead of the outer fan 100. Hereinafter, the X-ray CT apparatus 2 will be explained focusing on these differences, and the explanation of common configurations may be omitted.

In the X-ray CT apparatus 2 of the second embodiment, the rotating frame 17 includes a third rotating frame 81 and a fourth rotating frame 82. The rotating frame 17 has a two-layer structure in which a fourth rotating frame 82 is placed in front of a third rotating frame 81. A clutch mechanism 70 is provided between the third rotating frame 81 and the fourth rotating frame 82. The third rotating frame 81 and the fourth rotating frame 82 are rotatable independently of each other when the clutch mechanism 70 is disconnected.

The fourth rotation frame 82 is arranged in parallel with the third rotation frame 81 along the rotation axis of the rotation frame 17 within the cover 20 and is disposed in front of the third rotation frame 81 . The fourth rotation frame 82 rotates in the first rotation direction to ventilate the inside of the cover 20 and exhaust the air in the internal space of the cover 20 to the outside of the cover 20 to exhaust heat.

A plurality of front fins 83 are provided upright on the front surface of the fourth rotating frame 82, which is the opposite surface to the third rotating frame 81. The fourth rotating frame 82 and the front fins 83 constitute a front fan 200 . The plurality of front fins 83 have the same shape and are arranged at equal intervals around the rotation axis of the fourth rotation frame 82. The plurality of front fins 83 face the same direction and are shaped to guide the air inside the cover 20 rearward when the front fan 200 rotates in the first rotation direction.

A back plate 84 is provided on the back side of the third rotating frame 81. The back plate 84 has a disc shape with a plurality of holes. The fourth rotating frame 82 is arranged in front of the back plate 84 and parallel to the back plate 84. A plurality of ventilation holes 85 are provided on the circumferential surface of the third rotating frame 81. The back plate 84 is provided with an inner opening 86 having approximately the same diameter as the circular opening 21 . The fourth rotating frame 82 is an example of a second support, the front fan 200 is an example of a second fan, and the front fin 83 is an example of a fin.

When the front fan 200 rotates in the first rotation direction, the air within the cover 20 is discharged outward in the circumferential direction of the front fan 200 through the ventilation holes 85 by the suction force induced by the front fins 83 and guided forward. When the front fan 200 rotates in the first reverse rotation direction, the air inside the cover 20 flows in the opposite direction to when the front fan 200 rotates in the first rotation direction.

A motor 18 is connected to the front fan 200. The front fan 200 is rotated by being driven by the motor 18. The fourth rotating frame 82 is connected to the third rotating frame 81 via the clutch mechanism 70 and enters a cooperative state. The front fan 200 enters the cooperative state, so that the third rotating frame 81 rotates following the front fan 200. As shown in FIG. 9, the front fan 200 is in an independent state in which it is disconnected from the third rotating frame 81 by the clutch mechanism 70, and in an independent state in which it is disconnected from the third rotating frame 81 by the clutch mechanism 70, as shown in FIG. and a connected cooperative state.

In the independent state, the front fan 200 rotates only by the front fan 200, and in the cooperative state, the front fan 200 rotates together with the third rotating frame 81 following the third rotating frame 81. The front fan 200 and the third rotating frame 81 are capable of rotating independently of each other when the clutch mechanism 70 disconnects them.

Next, a model (hereinafter referred to as the "second model") when the front fan 200 of the X-ray CT apparatus 2 is rotated is created, and the results of an analysis of the air flow inside the cover 20 in the second model are created. I will explain about it. FIG. 12 is a vector diagram of the analysis results of the second model.

From the analysis results shown in FIG. 12, when the front fan 200 is rotated in the first rotation direction within the cover 20 of the X-ray CT apparatus 2, the air flow within the cover 20 is as shown below. First, air is introduced into the cover 20 from the air intake port 22 provided on the back surface of the cover 20. Air introduced into the cover 20 passes through a ventilation hole 85 provided in the front fan 200 and is guided forward. Thereafter, the air within the cover 20 is exhausted to the outside of the cover 20 through the exhaust port 23.

Further, the rotations of the outer fan 100 in the first model, the front fan 200 in the second model, and the conventional (current) X-ray CT apparatus (hereinafter referred to as "comparison apparatus") in which the fan is provided inside the cover 20 are explained. The results of an experiment regarding the relationship between speed and air volume inside the cover 20 will be explained.

On the other hand, in the first model and the second model, the faster the rotational speed of the outer fan 100 and the front fan 200, the larger the air volume. Therefore, unlike the comparison device, there is no need to provide a fan, which is a source of noise, in the cover 20 at a position close to the operator and the patient, so that noise can be reduced.

Furthermore, it was found that the X-ray CT apparatus 2 according to the second embodiment has a larger air volume relative to the fan rotation speed than the X-ray CT apparatus 1 according to the first embodiment. For this reason, it has been found that the X-ray CT apparatus 2 can generate more air volume within the cover 20 and enhance the cooling effect within the cover 20 than the X-ray CT apparatus 1.

In the X-ray CT apparatus 2, by rotating the front fan 200, the inside of the cover 20 can be ventilated, heat can be exhausted from the inside of the cover 20, and equipment inside the cover 20 can be cooled. Since the front fan 200 is arranged in parallel with the third rotating frame 81 along the rotation axis of the rotating frame 17 and in front of the third rotating frame 81, there is no need to provide a fan on the cover 20. It is possible to suppress the generation of a large amount of noise and vibration.

Furthermore, in the X-ray CT apparatus 2, a clutch mechanism 70 is provided between the third rotating frame 81 and the fourth rotating frame 82. Therefore, the front fan 200 is rotatable independently of the third rotating frame 81. Therefore, even when the third rotating frame 81 is not rotating, the inside of the cover 20 can be ventilated and heat can be exhausted. Furthermore, the cooling effect can be adjusted by setting the rotation speed of the front fan 200 and adjusting the air volume within the cover 20, regardless of the rotation speed of the third rotating frame 81. Furthermore, by arranging the front fan 200 along the rotation axis of the rotating frame 17, the amount of air inside the cover 20 can be increased.

(Third embodiment).
FIG. 13 is a diagram schematically showing the main parts of the X-ray CT apparatus 3 according to the third embodiment when viewed from the back. The X-ray CT apparatus 3 according to the third embodiment differs from the X-ray CT apparatus 1 according to the first embodiment in that it includes an inner fan 300. The X-ray CT apparatus 3 according to the third embodiment will be described below, focusing on the differences from the first embodiment, and the description of common configurations may be omitted.

The rotating frame 17 in the X-ray CT apparatus 3 of the third embodiment includes a first rotating frame 61, a second rotating frame 62, and a fifth rotating frame 67. The rotating frame 17 of the third embodiment has a three-layer structure in which the second rotating frame 62 is arranged outside the first rotating frame 61 and the fifth rotating frame 67 is arranged inside the first rotating frame 61.

A plurality of inner fins 68 are provided inside the fifth rotation frame 67, and a front side plate similar to the front plate provided on the front surface of the second rotation frame 62 is provided on the front side of the fifth rotation frame 67. . The plurality of inner fins 68 have the same shape. The plurality of inner fins 68 are oriented in the same direction and are shaped to guide the air inside the cover 20 rearward when the fifth rotation frame 67 rotates in the first rotation direction. Although no ventilation holes are formed in the fifth rotation frame 67, ventilation holes similar to the ventilation holes 65 formed in the second rotation frame 62 may be formed. The fifth rotating frame 67 and the inner fins 68 constitute a third fan.

The outer fan 100 and the inner fan 300 are connected to rotate simultaneously. Therefore, the inner fan 300 follows the outer fan 100 and moves together with the outer fan 100. Inner fan 300 may be rotatable independently from outer fan 100. In this case, the inner fan 300 may be connected to the first rotating frame 61 and the outer fan 100 via a clutch mechanism, and the motor may be connected to either or both of the outer fan 100 and the inner fan 300. Good too. The inner fan 300 is an example of a second fan, and the fifth rotating frame 67 is an example of a second support.

When the inner fan 300 rotates in the first rotation direction, the air within the cover 20 is discharged to the outside in the circumferential direction of the support cylinder through the ventilation holes 65 by the suction force induced by the inner fins 68, and is guided forward. When the inner fan 300 rotates in the first reverse rotation direction, the air inside the cover 20 flows in the opposite direction than when the inner fan 300 rotates in the first rotation direction.

In the X-ray CT apparatus 3 according to the third embodiment, an outer fan 100 similar to that of the first embodiment is provided on the outer periphery of the first rotating frame 61, and an inner fan 300 is provided on the inner periphery of the first rotating frame 61. It is set in. Therefore, the inside of the cover 20 can be ventilated by the inside fan 300 together with the outside fan 100, heat can be exhausted from inside the cover 20, and the effect of cooling the equipment inside the cover 20 can be further enhanced.

(Fourth embodiment).
FIG. 14 is a schematic side view of the main parts of the X-ray CT apparatus 4 according to the fourth embodiment. The X-ray CT apparatus 4 according to the fourth embodiment differs from the X-ray CT apparatus 1 according to the second embodiment in that it includes a rear fan 400. The X-ray CT apparatus 4 according to the fourth embodiment will be described below, focusing on the differences from the second embodiment, and the description of common configurations may be omitted.

The rotating frame 17 in the X-ray CT apparatus 4 of the fourth embodiment includes a third rotating frame 81, a fourth rotating frame 82, and a sixth rotating frame 87. The rotating frame 17 of the third embodiment has a three-layer structure in which a fourth rotating frame 82 is arranged on the front side of a third rotating frame 81 and a sixth rotating frame 87 is arranged on the rear side of the third rotating frame 81. .

A plurality of rear side fins 88 are provided on the rear side of the sixth rotating frame 87 that is opposite to the rotating frame 17 . The plurality of rear fins 88 have the same shape. The plurality of rear fins 88 face the same direction and are shaped to guide the air inside the cover 20 rearward when the sixth rotation frame 87 rotates in the first rotation direction. The rear fan 400 is an example of a second fan, and the sixth rotating frame 87 is an example of a second support. The sixth rotating frame 87 and the rear fin 88 constitute a fourth fan.

The front fan 200 and the rear fan 400 are connected to rotate simultaneously. Therefore, the rear fan 400 follows the front fan 200 and moves together with the front fan 200. The rear fan 400 may be rotatable independently from the front fan 200. In this case, the rear fan 400 may be connected to the first rotating frame 61 and the front fan 200 via a clutch mechanism, and the motor may be connected to either or both of the front fan 200 and the rear fan 400. You can leave it there.

When the rear fan 400 rotates in the first rotation direction, the air inside the cover 20 is discharged outward in the circumferential direction of the rotary frame 17 through the ventilation holes provided in the first rotary frame 61 by the guidance of the rear fins 88. , guided forward. When the rear fan 400 rotates in the first reverse rotation direction, the air inside the cover 20 flows in the opposite direction to when the rear fan 400 rotates in the first rotation direction.

The X-ray CT apparatus 4 according to the fourth embodiment has a front fan 200 similar to the second embodiment.
is provided on the front side of the first rotating frame 61, and a rear fan 400 is provided on the rear side of the first rotating frame 61. Therefore, the inside of the cover 20 can be ventilated by the front fan 200 and the rear fan 400, heat can be exhausted from the inside of the cover 20, and the effect of cooling the equipment inside the cover 20 can be further enhanced.

In each of the above embodiments, instead of the motor that rotates the outer fan 100 or the front fan 200, a motor that rotates the rotating frame 17 may be provided separately, or a motor that rotates the outer fan 100 or the front fan 200 and a A motor for rotating the frame 61 for one rotation may be provided separately. If a motor that rotates the first rotating frame 61 is provided separately together with a motor that rotates the outer fan 100 or the front fan 200, the clutch mechanism 70 that connects the outer fan 100 or the front fan 200 and the first rotating frame 61 is not provided. It's okay.

In the first embodiment, the outer fan 100 is provided, and the inner fan 300 as in the third embodiment is not provided. On the other hand, the outer fan 100 may not be provided and only the inner fan 300 may be provided. In the second embodiment, a front fan 200 is provided, and a rear fan 400 as in the fourth embodiment is not provided. On the other hand, the front fan 200 may not be provided and only the rear fan 400 may be provided. Furthermore, one or both of the outer fan 100 and the inner fan 300, and one or both of the front fan 200 and the rear fan 400 may be provided.

In each of the above embodiments, the control device 25 may adjust the output of the outer fan 100 and the front fan 200 by controlling the amount of rotation of the motor 18 based on the temperature inside the cover 20. The control device 25 in this case is an example of an output control section. For example, the output of the outer fan 100 etc. may be increased as the temperature inside the cover 20 is higher, and the output of the outer fan 100 etc. may be decreased as the temperature inside the cover 20 is lower. Alternatively, the outer fan 100 may be stopped when the temperature inside the cover 20 is less than a predetermined threshold value, and the outer fan 100 etc. may be started to rotate when the temperature inside the cover 20 is equal to or higher than the threshold value. Accordingly, the output of the outer fan 100 may be increased sequentially.

According to at least one embodiment described above, there is provided a cover provided with an opening for inserting a subject, a rotating body provided in the internal space of the cover and rotating around the opening, and the internal space. a first fan that exhausts air inside the cover to the outside of the cover; the first fan includes a first support that is coaxial with the rotating body and rotatable independently of the rotating body; By having the fins provided on the support body, it is possible to exhaust heat from inside the cover of the pedestal even when the rotating body is not rotating, while suppressing the generation of a large amount of noise and vibration.

Although several embodiments have been described, these embodiments are presented by way of example 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 changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

DESCRIPTION OF SYMBOLS 1-4... X-ray CT apparatus, 10... Frame device, 17... Rotating frame, 18... Motor, 19... Bearing, 20... Cover, 21... Circular opening, 22... Intake port, 23... Exhaust port, 25... Control device , 30... Bed device, 40... Console device, 41... Memory, 42... Display, 43... Input interface, 50... Processing circuit, 61... First rotating frame, 62... Second rotating frame, 63... Outer fin, 64... Back plate, 65... Ventilation hole, 66... Inner opening, 67... Fifth rotating frame, 68... Inner fin, 70... Clutch mechanism, 81... Third rotating frame, 82... Fourth rotating frame, 83... Front side fin, 84 ...Back plate, 85...Vent hole, 86...Inner opening, 87...Sixth rotating frame, 88...Rear side fin, 100...Outer fan, 200...Front fan, 300...Inner fan, 400...Rear fan

Claims (11)

a cover provided with an opening for inserting a subject;
a rotating body provided in the cover and rotating around the opening;
a first fan that exhausts air in the internal space of the cover to the outside of the cover;
The first fan is
a first support that is coaxial with the rotating body and rotatable independently of the rotating body;
fins provided on the first support;
X-ray CT device. further comprising a switching mechanism that switches the first fan between an independent state in which the first fan is rotated independently of the rotating body and a cooperative state in which the first fan is connected to the rotating body and rotates together with the rotating body;
The X-ray CT apparatus according to claim 1. The switching mechanism includes a clutch mechanism that connects the first support and the rotating body.
The X-ray CT apparatus according to claim 2. further comprising a control device that performs switching control to cause the switching mechanism to switch the first fan between the independent state and the cooperative state;
The X-ray CT apparatus according to claim 2 or 3. further comprising a drive unit that rotates the first fan;
The X-ray CT apparatus according to any one of claims 1 to 4. the first support body is arranged on the outer periphery of the rotating body,
The fins are provided on the outer periphery of the first support,
The X-ray CT apparatus according to any one of claims 1 to 5. The first support body is arranged in parallel with the rotating body along the rotation axis of the rotating body,
The fins are provided on a surface of the first support body opposite to the rotating body,
The X-ray CT apparatus according to any one of claims 1 to 5. further comprising a second fan that exhausts air in the internal space to the outside of the cover,
The second fan is
a second support that is coaxial with the rotating body and the first support and rotatable independently from the rotating body and the first support;
fins provided on the second support;
The X-ray CT apparatus according to any one of claims 1 to 5. further comprising a second fan disposed on the inner periphery of the rotating body to exhaust air in the internal space to the outside of the cover;
The second fan is
a second support disposed on the inner periphery of the rotary body, coaxial with the rotary body and the first support, and rotatable independently from the rotary body and the first support;
fins provided on the inner periphery of the second support;
The X-ray CT apparatus according to claim 6. further comprising a second fan that is disposed on the opposite side of the rotating body from the side where the first fan is provided and exhausts air in the internal space to the outside of the cover;
The second fan is
a second support that is coaxial with the rotating body and the first support and rotatable independently from the rotating body and the first support;
a fin provided on a surface of the second support body opposite to the side on which the rotating body is provided;
The X-ray CT apparatus according to claim 7. further comprising an output control section that controls the output of the first fan,
The output control unit adjusts the output of the first fan based on the temperature inside the cover.
The X-ray CT apparatus according to any one of claims 1 to 10.

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