Mobile radiation imaging device

Abstract

The radiation imaging device comprises: an irradiation unit that irradiates radiation; a trolley unit that is equipped with the irradiation unit and is capable of traveling; a steering caster that is provided on the trolley unit and is connected to a steering wheel and is provided with a steering angle by operating the steering wheel; a free caster that is provided on the trolley unit and is not connected to the steering wheel and is configured to change the steering angle in a driven manner according to the direction of a force applied to the trolley unit; and a switching mechanism that selectively switches between a first ground contact state in which the free caster is separated from the floor and the steering caster is in contact with the floor and a second ground contact state in which the free caster is in contact with the floor and the steering caster is separated from the floor.

Description

Technical Field

[0001] The present invention relates to a mobile radiation imaging device. Background Art

[0002] A mobile radiographic imaging device is known that includes an irradiation unit that irradiates radiation and a movable carriage unit (see Japanese Patent Application Laid-Open No. 2011-87923). The carriage unit is provided with a plurality of casters and carries a support unit that supports an arm provided with the irradiation unit and a main body unit.

[0003] The trolley of the mobile radiographic imaging device (X-ray imaging device) described in Japanese Patent Publication No. 2011-87923 is provided with two types of casters, namely, a steering caster (main wheel) and a free caster (auxiliary wheel). The steering caster is a caster coupled to a steering wheel, and a steering angle is given by the operation of the steering wheel. Thus, the traveling direction of the trolley can be fixed by the operation of the steering wheel. The free caster is not connected to the steering wheel and changes the steering angle according to the force applied to the trolley. Summary of the invention

[0004] Technical issues to be solved by the invention

[0005] In addition to being used in a photography studio, this type of mobile radiographic camera is sometimes used in a ward and an operating room. When photographing a patient who is difficult to move to a photography studio, the mobile radiographic camera is carried to the patient's ward and used there. Also, when performing animated photography of a treatment target part of a patient undergoing surgery, the mobile radiographic camera is carried to an operating room and used there. Considering the use of the mobile radiographic camera in multiple usage scenarios, the operability required of the trolley unit varies depending on each usage scenario.

[0006] For example, a ward is narrower than a radiography room, so it is necessary to be more flexible and flexible in turning than in a radiography room. In addition, when using the device in a narrow ward with many obstacles such as beds, it is desirable to be able to easily change the direction of the trolley by pushing and pulling the mobile radiography device from all directions without having to bother operating the steering wheel. On the other hand, during surgery, for example, it is sometimes necessary to move the radiography position sequentially along the patient's body axis while shooting. In this case, if the trolley shakes, accurate shooting cannot be performed, so it is desirable to fix the direction of travel of the trolley by fixing the position of the steering wheel.

[0007] In the mobile radiographic imaging device described in Japanese Patent Publication No. 2011-87923, the steering casters always touch the ground, so the direction of travel of the trolley is fixed by the position of the steering wheel. Therefore, if the steering wheel is not operated, it is difficult to change the direction of the trolley, so the trolley is not flexible in small turns and is inconvenient to use in a narrow ward. On the other hand, when using a trolley with only free casters but no steering casters, small turns are flexible, but it is inconvenient to use when the direction of travel of the trolley is desired to be fixed. In this way, the operability required of the trolley changes according to the usage scenario.

[0008] The technology according to the present invention provides a mobile radiation imaging device capable of changing the operability of a carriage unit according to the usage scene.

[0009] Means for solving technical problems

[0010] The mobile radiation imaging device involved in the first embodiment of the present invention comprises: an irradiation unit that irradiates radiation; a trolley unit that carries the irradiation unit and is capable of traveling; a steering caster that is arranged on the trolley unit and connected to a steering wheel, and a steering angle is given by operating the steering wheel; a free caster that is arranged on the trolley unit and is not connected to the steering wheel, and a steering angle is changed according to the direction of a force applied to the trolley unit; and a switching mechanism that selectively switches between a first ground contact state in which the free caster is separated from the floor and the steering caster is in contact with the floor and a second ground contact state in which the free caster is in contact with the floor and the steering caster is separated from the floor.

[0011] According to the above configuration, the ground contact state of the free caster and the steering caster is selectively switched by the switching mechanism, so that the operability of the carriage part can be changed according to the usage scene.

[0012] That is, regarding the operability of the carriage, by making the free casters touch the ground, the carriage becomes flexible in small turns, and by making the steering casters touch the ground, the traveling direction of the carriage can be fixed. If the small turns are flexible, it is convenient to use in a narrow ward. If the traveling direction can be fixed, it is convenient to use when continuously shooting while moving the shooting position.

[0013] A mobile radiographic imaging device according to a second aspect of the present invention is the mobile radiographic imaging device according to the first aspect, wherein the switching mechanism switches between the first ground contact state and the second ground contact state by raising and lowering the free caster relative to the steering caster.

[0014] Generally, the steering caster is connected to the steering wheel and is therefore heavier than the free caster. According to the above structure, the free caster side is raised and lowered by the switching mechanism, so that the ground contact state of the caster can be easily switched with a lighter force than the structure that raises and lowers the steering caster side.

[0015] A mobile radiographic imaging device according to a third aspect of the present invention is the mobile radiographic imaging device according to the second aspect, wherein the switching mechanism includes a pedal for raising and lowering the free caster.

[0016] According to the above configuration, the free caster can be raised and lowered by stepping on the pedal, so the ground contact state of the caster can be switched while operating the mobile radiation imaging device by hand.

[0017] The mobile radiation imaging device according to the fourth aspect of the present invention is a mobile radiation imaging device according to any one of the first to third aspects, and is provided with casters that always contact the floor in either the first contact state or the second contact state, in addition to free casters and steering casters.

[0018] According to the above structure, in addition to the free caster and the steering caster, the caster that always touches the ground is also provided, so that even if one of the free caster and the steering caster is separated from the floor, the carriage part can be stably driven. In addition, the posture of the carriage part is prevented from becoming unstable when the contact state of the free caster and the steering caster is switched.

[0019] The mobile radiation imaging device involved in the fifth embodiment of the present invention is a mobile radiation imaging device involved in the fourth embodiment, in which an arm supporting an irradiation unit and a main body having a control unit for controlling the irradiation unit are mounted on a trolley unit, and the casters that always touch the ground are casters that change the steering angle passively, similar to the free casters. When the side where the arm is provided is set as the front of the trolley unit and the side where the main body is provided is set as the rear of the trolley unit, the casters that always touch the ground, the steering casters and the free casters are arranged in this order from the front to the rear of the trolley unit.

[0020] According to the above structure, by arranging the steering caster between the ground-contacting caster and the free caster in the front-rear direction of the main body, the steering caster can be arranged at a position close to the center of gravity of the main body.

[0021] A mobile radiographic apparatus according to a sixth aspect of the present invention is the mobile radiographic apparatus according to the fifth aspect, wherein the steering casters are disposed at the center of gravity in the front-rear direction of the carriage portion.

[0022] According to the above configuration, by arranging the steering casters at the center of gravity of the entire mobile radiographic imaging device, it is possible to further suppress the posture of the main body from becoming unstable when the steering wheel is operated.

[0023] The mobile radiation imaging device involved in the 7th aspect of the present invention is a mobile radiation imaging device involved in the 5th aspect or the 6th aspect, wherein the arm has two ends, and an irradiation portion is provided at one end of the arm and an image receiving portion is provided at the other end of the arm for receiving radiation irradiated from the irradiation portion and transmitted through the subject.

[0024] According to the above configuration, the irradiation unit and the image receiving unit can be integrally held on the arm, so that, for example, imaging can be performed while the carriage unit is moved in the body axis direction of the subject during surgery.

[0025] The mobile radiation imaging device according to the eighth aspect of the present invention is a mobile radiation imaging device according to any one of the first to seventh aspects, and has a steering wheel locking mechanism, which locks the operation based on the steering wheel in the second ground contact state in which the steering casters are separated from the floor.

[0026] According to the above structure, the steering wheel locking mechanism is provided, which locks the operation based on the steering wheel when the steering caster is separated from the floor. This can prevent the steering caster from moving when the main body is moved by the free caster, thereby preventing the posture of the mobile radiation imaging device from becoming unstable.

[0027] A mobile radiographic imaging device according to a ninth aspect of the present invention is the mobile radiographic imaging device according to any one of the first to eighth aspects, wherein the handle for pushing and pulling the carriage portion is provided separately from the steering wheel.

[0028] According to the above configuration, since the handle for pushing and pulling the cart portion is provided separately from the steering wheel, the operation is easy when the cart portion is driven by the free casters.

[0029] Effects of the Invention

[0030] According to the technology involved in the present invention, the operability of the cart unit can be changed according to the usage scene. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is an overall perspective view showing a mobile radiation imaging device according to an example of the embodiment.

[0032] Figure 2A It is a side view of a mobile radiation imaging device according to an example of the embodiment.

[0033] Figure 2B It means to make Figure 2A 1 is a side view of the mobile radiation imaging device shown in the state where the arm is rotated in the direction of arrow M1.

[0034] Figure 2C It means to make Figure 2A 1 is a side view of the mobile radiation imaging device shown in the state where the arm is rotated in the direction of arrow M2.

[0035] Figure 3A This is a front view of a mobile radiation imaging device according to an example of an embodiment.

[0036] Figure 3B It means to make Figure 3A The mobile radiation imaging device shown is a front view of a state in which the arm is rotated in the direction of arrow N1.

[0037] Figure 3C It means to make Figure 3A The mobile radiation imaging device shown is a front view of a state in which the arm is rotated 180 degrees in the direction of arrow N2.

[0038] Figure 4 This is an overall side view showing a first ground contact state of the mobile radiation imaging device according to an example of the embodiment.

[0039] Figure 5 It is an overall side view showing a second ground contact state of the mobile radiation imaging device according to an example of the embodiment.

[0040] Figure 6 It is a plan view showing a mobile radiation imaging device according to an example of the embodiment.

[0041] Fig. 7A It means that Figure 6 A plan view of the mobile radiation imaging device shown in FIG. 1 , in a state where the steering wheel is operated in one direction.

[0042] Figure 7B It means that Figure 6 A plan view of the mobile radiation imaging device shown in FIG. 1 in a state where the steering wheel is operated in another direction.

[0043] Figure 8 It is a perspective view showing a switching mechanism of a mobile radiation imaging device according to an example of the embodiment.

[0044] Fig. 9 yes Figure 8 An exploded perspective view of the switching mechanism shown.

[0045] Fig.10 It is a side view showing the switching mechanism in the first contact state.

[0046] Fig.11 It is a side view showing the switching mechanism in the second ground contact state.

[0047] Fig. 12AIt is a perspective view showing the unlocked state of the steering wheel by the steering wheel locking mechanism.

[0048] Fig. 12B It is a perspective view showing a locked state of the steering wheel by the steering wheel locking mechanism. DETAILED DESCRIPTION

[0049] Hereinafter, a mobile radiographic imaging device according to an example of an embodiment of the present invention will be described with reference to the accompanying drawings. In the drawings, arrow X indicates the front-rear direction of the mobile radiographic imaging device, arrow Y indicates the width direction of the mobile radiographic imaging device, and arrow Z indicates the vertical direction.

[0050] (Overall Structure of Mobile Radiographic Imaging Device)

[0051] Figure 1 The mobile radiographic apparatus 10 of the present embodiment shown is an apparatus for capturing radiographic images of a subject H. The mobile radiographic apparatus 10 is capable of, for example, performing animation photography and still image photography of the subject H. Animation photography is performed, for example, when displaying the treatment target part of the subject H in the form of animation during surgery (also referred to as fluoroscopic photography, etc.). In animation photography, for example, an animation of the subject H is displayed on a monitor (not shown) that is provided separately from the mobile radiographic apparatus 10. Of course, the captured animation data can also be stored in the memory of the mobile radiographic apparatus 10. Furthermore, when performing still image photography, the captured still image can also be displayed on the monitor or stored in the memory of the mobile radiographic apparatus 10.

[0052] like Figure 1 As shown, the mobile radiation imaging device 10 includes an arm 12 (referred to as a C-arm, etc.) having a C-shaped (arc-shaped) side surface and a main body 16 having a support 14 mounted thereon. The arm 12, the support 14, and the main body 16 are mounted on a carriage 17. In the following, the side of the mobile radiation imaging device 10 on which the arm 12 is provided is set as the front of the mobile radiation imaging device 10, and the side on which the main body 16 is provided is set as the rear of the mobile radiation imaging device 10.

[0053] (Arm structure)

[0054] The arm 12 has two ends, and an irradiation unit 18 is provided at one end of the arm 12, and an image receiving unit 20 is provided at the other end. The arm 12 can hold the irradiation unit 18 and the image receiving unit 20 in an opposing posture. A space is ensured between the irradiation unit 18 and the image receiving unit 20 so that the subject H and the bed S on which the subject H lies supinely can be inserted. Figure 1When the arm 12 is viewed from the Y direction, the direction in which the irradiation unit 18 and the image receiving unit 20 are provided is sometimes referred to as the front of the arm 12 and the support unit 14 side is sometimes referred to as the rear of the arm 12.

[0055] like Figure 2A As shown, the arm 12 is configured to be able to perform orbital rotation around the axis M (axis parallel to the Y axis) relative to the rail portion 22B provided on the support portion 14. In addition, the arm 12 is configured to be able to perform axial rotation around the axis N (axis parallel to the X axis) relative to the bearing portion 23 provided on the main body 16.

[0056] Specifically, the rail portion 22B has an arc shape having the same radius as the arc of the arm 12. On the other hand, a fitting portion 22A that fits with the rail portion 22B is provided on the outer periphery of the arm 12. The fitting portion 22A has an arc shape along the shape of the arm 12. The rail portion 22B is, for example, in a groove shape, and the convex fitting portion 22A fits.

[0057] like Figure 2A As shown, the fitting portion 22A formed on the arm 12 slides along the rail portion 22B formed on the support portion 14. Thus, the arm 12 is provided to be able to orbitally rotate relative to the support portion 14 and the main body 16 about the axis M of the arc center of the arm 12 as the rotation center.

[0058] That is, Figure 2B and Figure 2C As shown, the arm 12 is configured to move in the direction of arrow M1 ( Figure 2B in the counterclockwise direction) and the direction of arrow M2 ( Figure 2C Thus, the irradiation unit 18 and the image receiving unit 20 provided at both ends of the arm 12 can be arranged to surround the subject H (reference Figure 1 )'s body axis (an axis parallel to the Y axis).

[0059] And, if Figure 2A As shown in FIG. 1 , one end of a support shaft 24 extending in the front-rear direction (X direction) of the mobile radiographic imaging device 10 is fixed to the arm 12. The other end of the support shaft 24 is supported by the main body 16 via a bearing 23. The support shaft 24 rotates relative to the bearing 23 about the axis N, as shown in FIG. Figure 3A to Figure 3C As shown, the arm 12 and the support portion 14 are provided so as to be axially rotatable with respect to the main body portion 16 about the axis line N of the support shaft 24 as the rotation center.

[0060] That is, Figure 3B and Figure 3C As shown, the arm 12 is configured to move around the axis N in the direction of the arrow N1 ( Figure 3B counterclockwise in the direction of arrow N2 ( Figure 3C Thus, the irradiation unit 18 and the image receiving unit 20 provided at both ends of the arm 12 can be made to be oriented relative to the subject H (reference Figure 1 )'s position in the up-and-down direction (Z-axis direction) is reversed.

[0061] Among them, about Figure 3A The arm 12 is in a posture in which the irradiation unit 18 is arranged above the image receiving unit 20, and the radiation tube 32 (see FIG. Figure 1 ) is located above the subject H. Therefore, this posture is called an outer tube posture, etc. Figure 3C In the posture of the arm 12 shown, the irradiation unit 18 is arranged below the image receiving unit 20 , and the radiation tube 32 is located below the subject H. Therefore, this posture is called a down-tube posture.

[0062] Compared with the lower tube posture, the outer tube posture can expand the distance between the irradiation unit 18 and the subject H (refer to Figure 1 ) between the two sides. Thus, in the overtube posture, a relatively wide area can be imaged. Therefore, the overtube posture is mainly used when capturing a still image of the subject H. On the other hand, in the undertube posture, the radiation irradiated from the irradiation unit 18 is partially shielded by the bed S and the like. Thus, in the undertube posture, the radiation irradiation on the subject H (reference Figure 1 ) to reduce the radiation dose to the surgeon or operator (not shown) around the subject. Therefore, the tube-down posture is used when capturing a moving picture of the subject H by continuously irradiating radiation.

[0063] (Structure of the main body)

[0064] like Figure 1 As shown, the main body 16 of the mobile radiation imaging device 10 has a control unit 28 for controlling each unit of the mobile radiation imaging device 10 such as the irradiation unit 18, and a touch panel type operation panel 30. In addition, the main body 16 has various switches (not shown) such as a power switch of the mobile radiation imaging device 10, a power circuit and a battery for supplying power to each unit of the mobile radiation imaging device 10, and the like.

[0065] The operation panel 30 functions as an operation unit for operating each unit of the mobile radiographic apparatus 10 by inputting operation commands to each unit, and functions as a display unit for displaying various information such as warning messages and radiographic images output from the image receiving unit 20 .

[0066] (Structure of control unit)

[0067] The control unit 28 controls the tube voltage, tube current, and radiation exposure time of the radiation tube 32 by sending a control signal to the radiation tube 32 of the irradiation unit 18 described later. The energy of the radiation is controlled by controlling the tube voltage by the control unit 28. In addition, the dose of the radiation is controlled by controlling the tube current and the irradiation time by the control unit 28. In practice, a high voltage is applied to the radiation tube 32, so the control unit 28 controls the radiation tube 32 through a high voltage generating device not shown. When performing imaging, imaging conditions including the tube voltage, tube current, and irradiation time are set through the operation panel 30. The control unit 28 operates the irradiation unit 18 according to the set imaging conditions.

[0068] The control unit 28 can perform animation photography of the subject H by causing the irradiation unit 18 to perform animation photography irradiation by continuously irradiating radiation from the irradiation unit 18. When performing animation photography, the control unit 28 causes the detector of the image receiving unit 20 described later to operate synchronously with the animation photography irradiation of the irradiation unit 18. When performing animation photography, basically, the irradiation time is not set as a photography condition, and commands for starting and ending the animation photography are issued through the operation panel 30. When a command for starting animation photography is input, the control unit 28 starts irradiating radiation from the irradiation unit 18 under the photography conditions set in advance.

[0069] In animation photography, when performing irradiation for animation photography, the detector repeatedly performs image detection at a preset frame rate. The image output by the detector is sent to the control unit 28. The control unit 28 sequentially outputs the received images to a monitor (not shown). As a result, an animation of the subject H is displayed on the monitor.

[0070] Furthermore, the control unit 28 can perform still image photography of the subject H by causing the irradiation unit 18 to execute irradiation for still image photography in which the irradiation unit 18 irradiates radiation in a shorter time than irradiation for moving image photography.

[0071] In still image photography, the control unit 28 causes the detector of the image receiving unit 20 to operate synchronously with the irradiation timing of the still image photography irradiation of the irradiation unit 18. The command for still image photography is issued, for example, through an irradiation switch (not shown) connected to the control unit 28. In the case of still image photography, the irradiation time is, for example, a time amount ranging from tens of milliseconds to hundreds of milliseconds. If a command for still image photography is input, the control unit 28 causes the irradiation unit 18 to operate according to the pre-set photography conditions. In the case of still image photography, the irradiation time is set in the photography conditions, so when the set irradiation time has passed, the irradiation of the irradiation unit 18 ends.

[0072] When the irradiation is finished, the detector starts to output the detected image. The image output by the detector is sent to the control unit 28. The control unit 28 stores the data of the still image in a memory not shown in the figure. And, the stored still image is displayed on a monitor not shown in the figure. Thus, a still image of the subject H is displayed on the monitor. And, in order to confirm the captured still image immediately after shooting, the still image can be displayed on the operation panel 30.

[0073] (Structure of irradiation section)

[0074] The irradiation unit 18 includes a radiation source 31 and an irradiation field limiter 34. The radiation source 31 includes a radiation tube 32 that generates radiation. The radiation is, for example, X-rays. The radiation tube 32 generates radiation by causing electrons generated from a cathode to collide with a target (anode). The position where the electrons collide with the target becomes the focus of the irradiated radiation.

[0075] Furthermore, an irradiation field limiter 34 is provided below the radiation source 31. The irradiation field limiter 34 (also referred to as a collimator, etc.) has a rectangular irradiation opening 34A. The radiation generated in the radiation tube 32 is irradiated to the subject H through the irradiation opening 34A. The irradiation field limiter 34 is capable of adjusting the opening area of ​​the irradiation opening 34A. The irradiation field limiter 34 has, for example, four shielding plates (not shown) for shielding the radiation. Each side of the four shielding plates corresponds to each side of the irradiation opening 34A and defines the irradiation opening 34A. The opening area of ​​the irradiation opening 34A is adjusted by changing the position of the shielding plate, thereby changing the irradiation field of the radiation irradiated from the irradiation unit 18.

[0076] Furthermore, the irradiation unit 18 is provided so as to be able to extend in the width direction ( Figure 1 Specifically, a pair of mounting plates 38 are fixed at one end of the arm 12. Figure 1 Only one of them is shown in the figure).

[0077] The pair of mounting plates 38 are arranged so as to sandwich both sides of the irradiation section 18 in the width direction, and are connected to both side surfaces of the irradiation section 18 in the width direction. Rotation shafts 36 are respectively provided protrudingly on the side surfaces of the irradiation section 18 that are opposite to the mounting plates 38, and the rotation shafts 36 are respectively supported on the pair of mounting plates 38 via bearings (not shown). Thus, the irradiation section 18 can rotate relative to the mounting plates 38 with the axis of the rotation shaft 36 as the rotation center, so that the direction of the irradiation opening 34A of the irradiation section 18 can be changed in the front-rear direction of the arm 12. The irradiation direction of the radiation can be changed by changing the direction of the irradiation opening 34A.

[0078] The irradiation unit 18 is connected to the control unit 28 of the main body 16 and a power circuit (not shown) through a cable (not shown) having a signal line for transmitting a control signal and a power supply line for power supply.

[0079] (Structure of image receiving unit)

[0080] like Figure 1 As shown, the image receiving unit 20 is provided at a position opposite to the irradiation unit 18, that is, at the other end of the arm 12. In addition, in the present embodiment, the image receiving unit 20 is non-detachably fixed to the other end of the arm 12, but the image receiving unit 20 may be detachably mounted to the other end of the arm 12.

[0081] The image receiving unit 20 includes a detector in a housing. The image receiving unit 20 includes an image receiving surface 20A that receives radiation irradiated from the irradiation unit 18 and transmitted through the subject H. The radiation carrying information about the subject H is incident on the image receiving surface 20A.

[0082] The detector is, for example, a flat panel detector (FPD) of a digital radiography (DR) method. The FPD has a detection surface in which a plurality of pixels are arranged two-dimensionally and a thin film transistor (TFT) panel (not shown) for driving the pixels. Radiation is incident on the detection surface of the detector through the image receiving surface 20A. The detector converts the incident radiation into an electrical signal and outputs a radiation image representing the subject H based on the converted electrical signal. As a detector, for example, an indirect conversion type is used, which converts radiation into visible light through a scintillator and converts the converted visible light into an electrical signal. In addition, as a detector, it can be a direct conversion type that converts radiation into a direct electrical signal. Furthermore, as the image receiving unit 20, it can be a structure other than the structure using the FPD, for example, it can also be a structure combining an image intensifier (II; Image Intensifier) ​​and a camera.

[0083] The image receiving unit 20 is connected to the control unit 28 of the main body 16 and a power supply circuit (not shown) through a cable (not shown) having a signal line for transmitting a control signal and a power supply line for power supply.

[0084] (Structure of the carriage)

[0085] like Figures 4 to 6 As shown, the carriage 17 is rectangular in plan view and is mounted on the lower surface of the main body 16. The main body 16, the arm 12, and the irradiation unit 18 and the image receiving unit 20 supported by the arm 12 of the mobile radiation imaging device 10 are all mounted on the carriage 17.

[0086] The carriage part 17 is provided with a plurality of casters 26 at the bottom thereof and is capable of traveling. Therefore, the mobile radiographic imaging device 10 can be driven by an operator manually to travel in, for example, an operating room or a hospital ward.

[0087] like Figure 6 As shown, the casters 26 are composed of a pair of steering casters 40, a pair of free casters 42, and a pair of ground-contacting casters 44. That is, the carriage 17 has a total of six casters 26. The casters 26 are arranged on the carriage 17 in the order of the ground-contacting casters 44, the steering casters 40, and the free casters 42 from the front to the rear of the carriage 17, that is, from the front to the rear of the mobile radiographic imaging device 10.

[0088] Specifically, a pair of ground-contacting casters 44 are provided in front of the carriage 17 in the width direction ( Figure 6 In addition, a pair of steering casters 40 are provided at the width direction (Y direction) of the carriage part 17 at the approximate center in the front-to-back direction of the carriage part 17, that is, at the center of gravity in the front-to-back direction of the mobile radiographic imaging device 10 as a whole. Figure 6 In addition, a pair of free casters 42 are arranged at the rear of the carriage 17 in the width direction ( Figure 6 at both ends of the Y direction).

[0089] Each of the pair of free casters 42 independently rotates around the axle D1 extending in the horizontal direction (Y direction) as the center, and independently rotates around the rotation axis H1 extending in the vertical direction (Z direction) as the center. In addition, the pair of free casters 42 are not connected to the steering wheel 48 provided on the main body 16, which will be described later, and the steering angle is changed according to the direction of the force applied to the carriage part 17.

[0090] A pair of casters 44 that always touch the ground are Figure 4 The caster 44 that is always in contact with the floor 46 shown in the figure. Here, "always" means that it is always in contact with the ground in any of the first contact state and the second contact state described later. Therefore, for example, when the trolley part 17 is tilted, the caster 44 that is always in contact with the ground is also separated from the floor 46. In the present embodiment, the caster 44 that is always in contact with the ground has the same structure as the free caster 42. That is, each of a pair of casters 44 that are always in contact with the ground independently rotates around the axle D2 extending in the horizontal direction (Y direction) as the center, and independently rotates around the rotation axis H2 extending in the vertical direction (Z direction) as the center. Moreover, like the free caster 42, the steering angle is changed passively according to the direction of the force applied to the trolley part 17.

[0091] Each of the pair of steering casters 40 independently rotates around the axle D3 extending in the horizontal direction (Y direction). The pair of steering casters 40 is connected to a steering wheel 48, which will be described later, provided on the main body 16, and a steering angle is given by operating the steering wheel 48. The pair of steering casters 40 rotate in the same direction in conjunction with each other by operating the steering wheel 48.

[0092] (Structure of the steering wheel)

[0093] like Figures 4 to 6 As shown in FIG. 1 , a steering wheel 48 for providing a steering angle to the steering caster 40 is provided on the main body 16 . The steering wheel 48 includes a rod 50 and a link mechanism 52 for transmitting the rotation of the rod 50 to the pair of steering casters 40 .

[0094] like Figure 4 and Figure 5 As shown, the lever 50 is mounted on the main body 16, for example, via a base 54 fixed to the upper surface of the main body 16. The lever 50 includes a rotating shaft 50A vertically arranged on the base 54 and mounted on the base 54 in a manner rotatable around the axis, and a grip 50B extending from the rotating shaft 50A in the radial direction outside (horizontal direction) of the rotating shaft 50A. The operator holds the grip 50B with his hand and rotates it around the axis of the rotating shaft 50A, thereby operating the lever 50.

[0095] The rod 50 can rotate within a range of about 90° to the left and right about the axis of the rotation shaft 50A, from the extending direction of the grip portion 50B of the rod 50 to the reference position in the front-back direction (X direction) of the mobile radiographic device 10. The rotation angle of the rod 50 can be adjusted to any angle within the rotatable range.

[0096] The link mechanism 52 includes: a shaft 56 whose upper end is fixed to the rotating shaft 50A of the rod 50 ; a pinion 58 fixed to the lower end of the shaft 56 ; a rack 60 meshing with the pinion 58 ; and a tie rod 62 connecting the rack 60 and the steering caster 40 .

[0097] If the operator moves the grip portion 50B of the lever 50 around the axis of the rotation shaft 50A ( Figure 6 When the pinion 58 is rotated, the rack 60 meshing with the pinion 58 rotates in conjunction with the rotation of the pinion 58 and moves in the width direction (in the direction of the arrow R in the figure) of the carriage 17. Figure 6 The movement of the rack 60 is transmitted to the steering caster 40 via the tie rod 62, thereby causing the steering caster 40 to rotate.

[0098] Specifically, if Fig. 7A As shown, when the rod 50 is rotated in the left direction (arrow R1 direction), the rack 60 of the link mechanism 52 moves to the left (arrow Y1), and the pair of steering casters 40 rotate in the right direction (arrow S1 direction). Thus, the carriage part 17 can be moved in the right direction.

[0099] On the other hand, Figure 7B As shown, when the rod 50 is rotated in the right direction (arrow R2 direction), the rack 60 of the link mechanism 52 moves to the right (arrow Y2 direction), and the pair of steering casters 40 rotate in the left direction (arrow S2). Thus, the carriage part 17 can be moved in the left direction.

[0100] (Structure of switching mechanism)

[0101] And, if Figures 4 to 6 As shown in FIG. 1 , a switching mechanism 64 is provided on the carriage portion 17. The switching mechanism 64 selectively switches between the first ground contact state and the second ground contact state by raising and lowering the free caster 42 relative to the steering caster 40.

[0102] Among them, Figure 4 As shown in FIG. 1 , the first ground contact state is a ground contact state in which the free caster 42 is separated from the floor 46 and the steering caster 40 is in contact with the floor 46. Figure 5 As shown, the second ground contact state is a ground contact state in which the free caster 42 is in contact with the floor 46 and the steering caster 40 is separated from the floor 46 .

[0103] Specifically, if Figure 8 and Fig. 9 As shown, the switching mechanism 64 includes a movable frame 66 and a first pedal 68 and a second pedal 70 as pedals for raising and lowering the free caster 42 .

[0104] The front end portion (the end portion on the front side) of the movable frame 66 is fixed to the shaft 72 via a bearing portion (not shown) so as to be rotatable around the axis of the shaft 72. Figure 4 The trolley portion 17 shown in the figure extends in the width direction (Y direction), and both ends in the axial direction are fixed to the trolley portion 17. On the other hand, the free caster 42 is mounted on the rear end portion (end portion on the rear side) of the movable frame 66. That is, the free caster 42 is mounted on the trolley portion 17 via the movable frame 66.

[0105] The movable frame 66 rotates around the shaft 72 provided at the front end. The rear end of the movable frame 66 moves up and down in the vertical direction (Z direction) while drawing an arc by rotating around the shaft 72. In addition, the rear end of the movable frame 66 is urged upward in the vertical direction (Z direction) by a force-exerting member (not shown).

[0106] A pair of inclined surfaces 74 are formed on the upper surface of the rear end portion of the movable frame 66. The height of the pair of inclined surfaces 74 gradually increases from the rear end portion to the front end portion of the movable frame 66. A groove 76 is formed between the pair of inclined surfaces 74.

[0107] The first pedal 68 includes a base 68A provided at the front end (end on the front side) of the first pedal 68 and a tread surface 68B provided at the rear end (end on the rear side) of the first pedal 68. The base 68A is fixed to the shaft 78 via a bearing portion (not shown) so as to be rotatable around the axis of the shaft 78. The shaft 78 is arranged along Figure 4 The carriage portion 17 shown extends in the width direction (Y direction), and both end portions in the axial direction are fixed to the carriage portion 17 .

[0108] A bearing shaft 80 extending parallel to the shaft 78 is fixed to the lower portion of the shaft 78 in the base portion 68A of the first pedal 68. A pair of bearings 82 are fixed to the bearing shaft 80 so as to be rotatable around the axis of the bearing shaft 80.

[0109] The pair of bearings 82 are coaxially rotatable with each other and are provided at a distance in the axial direction of the bearing shaft 80. The pair of bearings 82 are movably mounted on a pair of inclined surfaces 74 formed on the movable frame 66 along the inclined surfaces 74.

[0110] The tread surface 68B of the first pedal 68 is fixed to the base 68A as a whole, and can rotate around the axis of the shaft 78 together with the base 68A. Figures 4 to 6 As shown in FIG. 1 , the tread surface 68B of the first pedal 68 protrudes toward the rear side of the carriage portion 17 . Thus, the operator can step on the tread surface 68B of the first pedal 68 from the outside of the mobile radiation imaging apparatus 10 .

[0111] like Figure 8 and Fig. 9 As shown, the second pedal 70 includes a base 70A provided at the front end (end on the front side) of the second pedal 70 and a tread surface 70B provided at the rear end (end on the rear side) of the second pedal 70. The base 70A is arranged in a groove 76 formed between a pair of inclined surfaces 74 of the movable frame 66, and is fixed to the shaft 84 via a bearing portion (not shown) so as to be rotatable around the axis of the shaft 84. The shaft 84 is arranged along Figure 4 The carriage portion 17 shown extends in the width direction (Y direction), and both ends in the axial direction are fixed to the movable frame 66 .

[0112] Furthermore, an abutment portion 86 is provided on the upper portion of the shaft 84 in the base portion 70A of the second pedal 70. The abutment portion 86 protrudes upward in the vertical direction (Z direction) from the groove 76 of the movable frame 66 and is located between the pair of inclined surfaces 74. Thus, the abutment portion 86 can abut against the pair of bearings 82 that move on the pair of inclined surfaces 74.

[0113] The tread surface 70B of the second pedal 70 is fixed to the base 70A as a whole, and can rotate around the axis of the shaft 84 together with the base 70A. Figure 6 As shown, the tread surface 70B of the second pedal 70 protrudes toward the rear side of the carriage portion 17, similarly to the tread surface 68B of the first pedal 68. Thus, the operator can step on the tread surface 70B of the second pedal 70 from outside the mobile radiographic apparatus 10.

[0114] When switching from the first contact state to the second contact state, the operator steps on the tread surface 68B of the first pedal 68 to lower the free caster 42 relative to the steering caster 40. Fig.10 As shown, when the operator steps on the tread surface 68B of the first pedal 68, the first pedal 68 moves about the axis of the shaft 78 in the direction of the arrow J1 ( Fig.10 At this time, the bearing 82 provided on the base 68A of the first pedal 68 moves forward along the inclined surface 74 of the movable frame 66 ( Fig.10 Move in the direction of arrow K1).

[0115] The height of the inclined surface 74 gradually increases from the rear end to the front end of the movable frame 66. Therefore, if the bearing 82 is moved forward, the inclined surface 74 is pushed downward in the vertical direction (Z direction) by the bearing 82. Fig.10 The movable frame 66 rotates in the counterclockwise direction (in the middle), and the rear end portion of the movable frame 66 descends.

[0116] Furthermore, when the bearing 82 of the first pedal 68 is moved forward along the inclined surface 74 of the movable frame 66, the bearing 82 abuts against the abutment portion 86 of the second pedal 70 provided between the pair of inclined surfaces 74 (see FIG. Fig.11 The abutment portion 86 is pushed forward by the bearing 82, so that the second pedal 70 moves about the axis of the shaft 84 in the direction of the arrow T1 ( Fig.10 As a result, the tread surface 70B of the second pedal 70 rises and is located at a position higher in the vertical direction (Z direction) than the tread surface 68B of the first pedal 68 (refer to Fig.11 ).

[0117] The free caster 42 is mounted on the lower surface of the rear end portion of the movable frame 66. Therefore, by lowering the rear end portion of the movable frame 66, the free caster 42 is moved relative to the carriage portion 17, that is, Figure 5 The steering caster 40 shown is lowered. Figure 5 and Fig.11 As shown, the free caster 42 is in contact with the floor 46, and the free caster 42 is located below the swivel caster 40. Thus, the swivel caster 40 is separated from the floor 46.

[0118] On the other hand, when switching from the second contact state to the first contact state, the operator steps on the tread surface 70B of the second pedal 70 to raise the free caster 42 relative to the steering caster 40. Fig.11 As shown, when the operator steps on the tread surface 70B of the second pedal 70, the second pedal 70 moves about the axis of the shaft 84 in the direction of arrow T2 ( Fig.11 At this time, the contact portion 86 provided on the base portion 70A of the second pedal 70 also rotates around the axis of the shaft 84 in the direction of arrow T2.

[0119] When the contact portion 86 is moved in the direction of arrow T2, the bearing 82 of the first pedal 68 is pushed by the contact portion 86, and the first pedal 68 moves about the axis of the shaft 78 in the direction of arrow J2 ( Fig.11 Thus, the bearing 82 moves backward along the inclined surface 74 of the movable frame 66 ( Fig.11 The first pedal 68 moves in the direction of the arrow K2 in the figure, and the tread surface 68B of the first pedal 68 rises.

[0120] When the bearing 82 moves backward, the inclined surface 74 pushed downward in the vertical direction (Z direction) by the bearing 82 rises upward in the vertical direction (Z direction) by the force of a force-applying member (not shown). Fig.11 The movable frame 66 rotates in the clockwise direction, and the rear end portion of the movable frame 66 rises.

[0121] The free caster 42 is mounted on the lower surface of the rear end portion of the movable frame 66. Therefore, by raising the rear end portion of the movable frame 66, the free caster 42 is moved relative to the carriage portion 17, that is, Figure 4 The steering caster 40 shown rises. Figure 4 and Fig.10 As shown, the free caster 42 is separated from the floor 46, and the free caster 42 is located above the swivel caster 40. As a result, the swivel caster 40 is in contact with the floor 46.

[0122] (Handle structure)

[0123] And, if Figure 4 and Figure 5 As shown, a pair of handles 88 for pushing and pulling the main body 16 (trolley 17) are fixed to the upper surface of the main body 16. The handles 88 are rod-shaped handles composed of, for example, a cylindrical rod having a substantially circular cross section.

[0124] The handle 88 extends along the front-rear direction (X direction) of the main body 16, and both ends of the extending direction are fixed to the upper surface of the main body 16. Figure 6 As shown, a pair of handles 88 are arranged at the rear of the main body 16 in the width direction ( Figure 6 at both ends of the Y direction).

[0125] When the mobile radiographic apparatus 10 moves, the operator grasps and pushes and pulls the pair of handles 88. The shape and fixed position of the handles 88 are not limited to those in the embodiment, and a shape and a position that are easy to grasp are appropriately selected.

[0126] (Structure of the steering wheel locking mechanism)

[0127] And, if Fig. 12A and Fig. 12B As shown, a steering wheel locking mechanism 90 is provided on the steering wheel 48. Figure 4 In the second ground contact state in which the steerable caster 40 is separated from the floor 46 , the operation based on the steering wheel 48 is locked.

[0128] In the present embodiment, as an example, the steering wheel lock mechanism 90 locks the rotation of the rod 50 constituting the steering wheel 48 relative to the base 54. Specifically, the steering wheel lock mechanism 90 includes a pin hole 92A formed on the upper surface of the base 54, a pin hole 92B formed on the flange portion 94 which is a contact portion with the base 54 of the rod 50, and a lock pin 96 inserted into the pin hole 92B of the rod 50. The pin hole 92B of the flange portion 94 of the rod 50 has a diameter substantially the same as that of the pin hole 92A of the base 54, and penetrates the flange portion 94 in the vertical direction (Z direction).

[0129] For example, when the gripping portion 50B of the rod 50 is located at a reference position (a position where the extending direction of the gripping portion 50B of the rod 50 becomes the front-to-back direction (X direction) of the mobile radiation imaging device 10), the pin hole 92B of the rod 50 is formed at a position connected to the pin hole 92A of the base 54.

[0130] like Fig. 12A As shown, when the pin hole 92A of the base 54 is not connected to the pin hole 92B of the rod 50, that is, when the holding portion 50B of the rod 50 is not located at the reference position, the locking pin 96 inserted into the pin hole 92B of the rod 50 cannot be inserted into the pin hole 92A of the base 54.

[0131] Therefore, the rod 50 can rotate about the axis of the rotation shaft 50A relative to the base 54. At this time, the steering caster 40 (see FIG. 5A ) can be operated by the rod 50 constituting the steering wheel 48. Figure 4 ).

[0132] On the other hand, Fig. 12B As shown, when the pin hole 92A of the base 54 is connected to the pin hole 92B of the rod 50, that is, when the gripping portion 50B of the rod 50 is located at the reference position, the locking pin 96 inserted into the pin hole 92B of the rod 50 can be inserted into the pin hole 92A of the base 54.

[0133] Therefore, by pushing the locking pin 96 from above so that the front end of the locking pin 96 is located in the pin hole 92A of the base 54, the rod 50 cannot rotate relative to the base 54. At this time, the steering caster 40 (see FIG. 1 ) based on the steering wheel 48 is Figure 4 ) operation is locked. In addition, the locking pin 96 can be manually inserted into the pin hole 92A, for example, it can also be electrically inserted into the pin hole 92A using a solenoid not shown in the figure.

[0134] (Effect)

[0135] According to the mobile radiographic imaging device 10 of this embodiment, the steering caster 40 to which the steering angle is given by the operation of the steering wheel 48 and the free caster 42 to which the steering angle is changed according to the direction of the force applied to the carriage 17 are provided on the carriage 17. Furthermore, the first ground contact state and the second ground contact state of the caster 26 can be selectively switched by the switching mechanism 64.

[0136] Therefore, by selectively switching the ground contact states of the free casters 42 and the steering casters 40 through the switching mechanism 64 , the operability of the carriage part 17 can be changed according to the usage scene.

[0137] That is, the travel direction of the carriage 17 can be fixed by setting the free caster 42 to the first ground contact state in which the free caster 42 is separated from the floor 46 and the steering caster 40 is in contact with the floor 46. If the travel direction of the carriage 17 can be fixed, it is convenient to use when continuously shooting while moving the shooting position.

[0138] For example, when photographing while changing the photographing part along the body axis direction of the subject H, it is convenient to use if the carriage unit 17 can be stably moved along the body axis direction of the subject H. The steering casters 40 can fix the steering angle by operating the steering wheel 48, so the carriage unit 17 does not shake when moving, and the travel direction is stable.

[0139] On the other hand, by setting the second ground contact state in which the free caster 42 is in contact with the floor 46 and the steering caster 40 is separated from the floor 46, the small turn of the carriage part 17 becomes flexible. If the small turn of the carriage part 17 is flexible, the direction of the carriage part 17 can be changed in a narrow space. Therefore, when the mobile radiation imaging device 10 is used in a narrow hospital room, it is convenient to use.

[0140] Furthermore, the switching mechanism 64 switches the ground contact state between the free caster 42 and the steering caster 40, so the structure is simple. For example, as a switching mechanism, a method of switching the effective state and the invalid state of the input of the operating force from the steering wheel 48 to the steering caster 40 can be considered in a state where the steering caster 40 is grounded. The so-called invalid state is a state in which the steering caster 40 functions as a free caster. Compared with a mechanism that switches the effective state and the invalid state of the input of the operating force from the steering wheel 48 in this way, a mechanism that switches the ground contact state is easier to simplify the structure.

[0141] Furthermore, according to the present embodiment, the switching mechanism 64 switches between the first ground contact state and the second ground contact state by raising and lowering the free caster 42 relative to the steering caster 40. Generally, the steering caster 40 is connected to the steering wheel 48 and is therefore heavier than the free caster 42. According to the present embodiment, the free caster 42 side is raised and lowered by the switching mechanism 64, so that the ground contact state of the caster 26 can be easily switched with a lighter force than the structure in which the steering caster 40 side is raised and lowered.

[0142] The switching mechanism 64 has a first pedal 68 and a second pedal 70 as pedals for raising and lowering the free caster 42. Therefore, the free caster 42 can be raised and lowered by stepping on the first pedal 68 or the second pedal 70, so the ground contact state of the caster 26 can be switched while the mobile radiation imaging device 10 is operated by hand.

[0143] In particular, according to the present embodiment, the pedal is composed of two pedals, namely, the first pedal 68 and the second pedal 70. When one of the pedals is lowered, the other pedal is raised. Usually, when the free caster 42 is raised or lowered by one pedal, the free caster 42 is lowered by lowering the pedal, and the free caster 42 is raised by raising the pedal. However, the load of the operation of lifting the pedal is greater than that of the operation of pressing the pedal.

[0144] According to the present embodiment, by combining two pedals, both the operation of raising the free caster 42 and the operation of lowering the free caster 42 can be realized by stepping on (pressing down) the pedals. Therefore, the ground contact state of the caster 26 can be easily switched.

[0145] Furthermore, in the present embodiment, the carriage portion 17 is provided with a constant ground contact caster 44 that is always in contact with the floor 46 in either the first ground contact state or the second ground contact state, in addition to the free caster 42 and the steering caster 40 .

[0146] Therefore, even if one of the free caster 42 and the steering caster 40 is separated from the floor 46, the carriage unit 17 can be stably driven. In addition, the posture of the carriage unit 17 is prevented from becoming unstable when the free caster 42 and the steering caster 40 are switched to the ground contact state.

[0147] Furthermore, according to the present embodiment, the casters 44 that always keep contact with the ground, the steering casters 40, and the free casters 42 are arranged in this order from the front to the rear of the carriage portion 17. In this way, by arranging the steering casters 40 between the casters 44 that always keep contact with the ground and the free casters 42, the steering casters 40 can be arranged at a position close to the center of gravity of the main body portion 16. Thus, when the steering wheel 48 is operated, the posture of the main body portion 16 can be prevented from becoming unstable.

[0148] In particular, according to the present embodiment, the steering casters 40 are arranged at the center of gravity of the entire mobile radiographic apparatus 10 in the front-rear direction of the carriage 17. This can further prevent the posture of the main body 16 from becoming unstable when the steering wheel 48 is operated.

[0149] Furthermore, the arm 12 of the mobile radiographic imaging device 10 of the present embodiment has two ends, and the irradiation unit 18 is provided at one end and the image receiving unit 20 is provided at the other end. Therefore, the irradiation unit 18 and the image receiving unit 20 can be integrally held on the arm 12. Thus, for example, during surgery, the trolley unit 17 can be moved along the body axis direction of the subject H while imaging is performed.

[0150] Furthermore, the mobile radiographic imaging device 10 of the present embodiment has a steering wheel locking mechanism 90 that locks the operation based on the steering wheel 48. Therefore, for example, in the second ground contact state in which the steering caster 40 is separated from the floor 46, the steering wheel locking mechanism 90 prevents the rod 50 from rotating relative to the base 54 (main body 16), thereby preventing the steering caster 40 from rotating. Thus, when the main body 16 is moved by the free caster 42, it is possible to prevent the posture of the mobile radiographic imaging device 10 from becoming unstable due to the movement of the steering caster 40.

[0151] Furthermore, according to the present embodiment, the handle 88 for pushing and pulling the carriage part 17 is provided separately from the rod 50 constituting the steering wheel 48. Thus, by providing the handle 88 separately from the rod 50, it is easy to operate when the carriage part 17 is driven by the free casters 42.

[0152] <Other Implementation Methods>

[0153] As mentioned above, although an example of embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and can be implemented in various forms within the scope not departing from the gist of the present invention.

[0154] For example, in the above-mentioned embodiment, the always-contacting caster 44 is a caster that changes the steering angle in a driven manner similar to the free caster 42. However, the always-contacting caster 44 may be a fixed caster that cannot turn.

[0155] Furthermore, the trolley portion 17 does not necessarily have to be provided with the casters 44 that always touch the ground. In the case where the casters 44 that always touch the ground are not provided, for example, by providing three or more steering casters 40 and free casters 42 respectively on the trolley portion 17, the trolley portion 17 can be made to travel stably. Furthermore, the arrangement of the casters 26 is not limited to the above-mentioned embodiment, and the steering casters 40 may also be arranged at a position further rearward than the casters 44 that always touch the ground and the free casters 42.

[0156] Furthermore, in the above-described embodiment, the free caster 42 is raised and lowered by the switching mechanism 64 , but a configuration in which the steering caster 40 is raised and lowered by the switching mechanism 64 may be adopted.

[0157] In the above embodiment, the handle 88 is provided on the upper surface of the main body 16. However, the mobile radiation imaging device 10 may be moved by pushing and pulling the lever 50 of the steering wheel 48 or directly pushing and pulling the main body 16 without providing the handle 88.

[0158] Furthermore, in the above embodiment, the link mechanism 52 of the steering wheel 48 is composed of the shaft 56, the pinion 58, the rack 60 and the tie rod 62, but the structure of the link mechanism 52 is not limited to the above embodiment, and other well-known link mechanisms may also be used.

[0159] Furthermore, in the above-described embodiment, the steering wheel locking mechanism 90 is a structure for locking the rotation of the rod 50 constituting the steering wheel 48. However, the steering wheel locking mechanism 90 may be a structure for locking the rotation of any one of the mechanisms constituting the steering wheel 48 and the steering caster 40, and may be, for example, a stopper for locking the rotation of the steering caster 40.

[0160] Furthermore, when the main body 16 is moved by the free caster 42 , if the movement of the steering caster 40 is allowed, the steering wheel lock mechanism 90 is not necessarily provided.

[0161] Furthermore, in the above embodiment, the arm 12 is described as a C-arm having a C-shaped side surface, but may be a U-arm having a U-shaped side surface. Furthermore, the arm 12 may be an I-arm having an I-shaped side surface with only the irradiation unit 18 provided at one end.

[0162] Furthermore, in the above embodiment, the irradiation unit 18 and the image receiving unit 20 are provided at both ends of the arm 12, respectively. However, the arm 12 need not necessarily be provided with the image receiving unit 20, and only the irradiation unit 18 may be provided.

[0163] Furthermore, in the above-described embodiment, X-rays are described as an example of radiation, but the radiation is not limited to X-rays, and may be gamma rays or the like.

[0164] The invention of Japanese Patent Application No. 2019-199331 filed on October 31, 2019 is incorporated herein by reference in its entirety. All documents, Japanese patent applications, and technical standards described in this specification are incorporated herein by reference in the same manner as if each document, Japanese patent application, and technical standard was specifically and individually described as being incorporated as a reference.

Claims

1. A mobile radiation imaging device comprising: An irradiation unit irradiates radiation; A carriage unit, which carries the irradiation unit and is capable of traveling; A steering caster, which is provided on the carriage portion and connected to a steering wheel, and a steering angle is given by operating the steering wheel; A free caster, which is provided on the carriage part and is not connected to the steering wheel, and which changes the steering angle according to the direction of the force applied to the carriage part; and The switching mechanism selectively switches between a first ground contact state in which the free caster is separated from the floor and the steering caster is in contact with the floor and a second ground contact state in which the free caster is in contact with the floor and the steering caster is separated from the floor.

2. The mobile radiation imaging device according to claim 1, wherein: The switching mechanism switches between the first ground contact state and the second ground contact state by raising and lowering the free caster relative to the steering caster.

3. The mobile radiation imaging device according to claim 2, wherein: The switching mechanism includes a pedal for raising and lowering the free caster.

4. The mobile radiation imaging device according to claim 1, wherein: The mobile radiographic imaging device is provided with a constant ground contact caster that is in contact with the floor in either the first ground contact state or the second ground contact state, in addition to the free caster and the steering caster.

5. The mobile radiation imaging device according to claim 4, wherein: An arm supporting the irradiation unit and a main body having a control unit for controlling the irradiation unit are mounted on the carriage unit. Similar to the free caster, the ground-contacting caster is a caster that changes the steering angle passively. When the side where the arm is provided is the front side of the carriage part and the side where the main body is provided is the rear side of the carriage part, The ground-contacting casters, the steering casters, and the free casters are arranged in this order from the front to the rear of the carriage portion.

6. The mobile radiation imaging device according to claim 5, wherein: The steering caster is arranged at a center of gravity in the front-rear direction of the carriage portion.

7. The mobile radiation imaging device according to claim 5, wherein: The arm has two ends, The irradiation part is provided at one end of the arm, An image receiving section that receives the radiation irradiated from the irradiation section and transmitted through the subject is provided at the other end of the arm.

8. The mobile radiation imaging device according to claim 1, wherein: The mobile radiographic imaging device includes a steering wheel locking mechanism configured to lock an operation based on the steering wheel in the second ground contact state in which the steering caster is separated from the floor.

9. The mobile radiation imaging device according to any one of claims 1 to 8, wherein: A handle for pushing and pulling the trolley portion is provided separately from the steering wheel.

Images