JP2007268060A - X-ray equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide X-ray equipment capable of avoiding contact of a plurality of units of X-ray equipment with each other and capable of simultaneously performing radiography from a plurality of different angles. <P>SOLUTION: A positional relation computing part determines whether the moving X-ray equipment will be brought into contact with other X-ray equipment or not (Step S4). If it is determined that the X-ray equipment is to be brought into contact with each other, further whether an FPD (a flat panel detector) is included in the contact area or not is determined (Step S5). If it is determined that the FPD is included, such direction and distance of movement of the FPD as to avoid the contact while transmitting X rays are projected on the detection flat panel of the FPD are found (Step S7), and the FPD is moved parallel on the retained flat plane according to the finding (Step S9). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a plurality of X-ray imaging mechanisms in which an X-ray tube for X-ray irradiation and an X-ray detector for transmission X-ray detection are arranged opposite to both ends of a support arm. The present invention relates to an X-ray imaging apparatus including an X-ray imaging system moving mechanism that moves a mechanism, and in particular, a technique that enables simultaneous imaging from a plurality of different desired angles while avoiding a contact accident of the X-ray imaging mechanism. About.

  2. Description of the Related Art Conventionally, a double imaging mechanism type X-ray imaging apparatus used in a medical institution such as a hospital includes two sets of X-ray imaging mechanisms 81 and 82 as shown in FIG. In one X-ray imaging mechanism 81, an X-ray tube 83 for X-ray irradiation and an X-ray detector 84 for detecting transmitted X-rays are disposed opposite to both ends of a supporting C-type arm 85. In the other X-ray imaging mechanism 82, an X-ray tube 86 and an X-ray detector 87 are disposed opposite to both ends of a supporting C-type arm 88. By rotating or translating the C-shaped arms 85 and 88 to move the X-ray imaging mechanisms 81 and 82, the X-ray imaging directions and positions of the respective X-ray imaging mechanisms 81 and 82 are matched to the imaging purpose. Set.

The X-ray imaging mechanisms 81 and 82 are controlled to move in accordance with a common position coordinate system with the mechanical center point (isocenter) of the apparatus as a reference point. Furthermore, while both X-ray imaging mechanisms are operating, information on the relative positional relationship is used so that the mutual X-ray imaging mechanisms do not come into contact with each other, and the approaching state is monitored in real time. Then, the movement of at least one X-ray imaging mechanism is stopped to avoid contact (for example, see Patent Document 1).
JP-T-2004-267625

  However, the conventional apparatus has the following problems.

  That is, in the conventional apparatus, when each X-ray imaging mechanism is set to a desired imaging direction, the X-ray imaging mechanisms and / or positions of the X-ray detectors that protrude beyond the outer shape of the arm holding portion contact each other. Therefore, there is a problem that photographing cannot be performed from the direction (angle) desired by the operator. That is, when the X-ray imaging mechanisms approach each other, a sufficient distance is secured so that the X-ray imaging mechanisms and / or the X-ray detector do not come into contact at all in consideration of the brake braking distance and the like. There is a problem that both X-ray imaging mechanisms cannot be brought close to a target distance. That is, a dead space that cannot be captured simultaneously using both X-ray imaging mechanisms is generated.

  Further, the X-ray detector detects transmitted X-rays so that the center of the detection surface has a cone beam-like beam diameter center. In this case, as shown in FIG. 9, the cone beam-shaped transmitted X-rays often do not spread over the entire surface including the end region of the detection surface of the X-ray detector. Therefore, the opening angle α formed by the two transmitted X-rays passing through the region of interest to be irradiated with X-rays is increased, and the dead space that cannot be imaged is further expanded.

  The present invention has been made in view of such circumstances, and an X-ray imaging apparatus capable of efficiently performing simultaneous imaging from a plurality of different desired angles while avoiding a contact accident of the X-ray imaging mechanism. The main purpose is to provide.

  In order to achieve such an object, the present invention has the following configuration.

  That is, the first invention includes an X-ray imaging mechanism in which an X-ray tube for X-ray irradiation and an X-ray detector for transmission X-ray detection are disposed opposite to both ends of a support arm. In an X-ray imaging apparatus having an X-ray imaging system moving mechanism for moving an X-ray imaging mechanism, X-ray detector movement for translating an X-ray detector arranged on an arm of the X-ray imaging mechanism on a holding plane A mechanism that detects when the X-ray imaging mechanism is moving and detects that it is approaching an object and outputs a detection signal; and when a signal is output from the detection means, the X-ray Movement for controlling the operation of the X-ray detector moving mechanism so that at least the X-ray detector moves in parallel on the holding plane of the arm so as to move away from the approaching object while bringing the imaging mechanism close. Characterized by mechanism control means

  [Operation / Effect] According to this configuration, when the X-ray imaging mechanism is operated, X-ray imaging is performed on an object (for example, another X-ray imaging mechanism, another device, a mechanism unit, and a structure). The approaching mechanism detects that the mechanism is approaching. The detection signal at this time is output to the moving mechanism control means. The movement mechanism control means that has received the detection signal brings the X-ray imaging system mechanism close to the object so as not to contact the object. At the same time, the X-ray detector moving mechanism is operated and controlled so that at least the X-ray detector provided in the X-ray imaging mechanism is separated in a direction to avoid contact with the object.

  Therefore, for example, if the object is another set of X-ray imaging mechanisms, the X-ray imaging system mechanisms can be brought closer to each other as compared with the conventional apparatus (claim 2). In other words, the X-ray imaging mechanisms can be brought close to each other by moving the X-ray detector protruding from the holding portion of the arm away from the contact target so as to be housed inside the arm holding portion. As a result, the X-ray detector can be effectively used up to the end of the detection surface, the X-rays projected on the X-ray detectors can be brought close to each other, and simultaneous imaging cannot be performed due to the proximity of both X-ray imaging mechanisms. Dead space can be minimized.

  In this configuration, the present invention may be configured as follows, for example.

  Based on the shape data registration means for registering 3D model outline data corresponding to the 3D outline shape of each X-ray imaging mechanism, the current position of each X-ray imaging mechanism and the 3D model outline data, It is composed of distance information between the X-ray imaging mechanisms and the X-ray detectors, and positional relationship calculation means for calculating information on the relative positional relationship between the X-ray imaging mechanisms and the X-ray detectors in real time. The mechanism control means moves each X-ray imaging mechanism according to a common position coordinate system with the mechanical center point of the apparatus as a reference point, while taking into account the information calculated by the positional relationship calculation means. It is preferable that the X-ray detector moving means is operated and controlled so that the X-ray detector moves in a direction avoiding contact while bringing the X-ray imaging mechanisms close to each other.

  The detecting means is a capacitance type proximity sensor, and the positional relationship calculating means calculates information on the relative positional relationship between the X-ray detectors in real time based on the capacitance change of each proximity sensor, and moves The mechanism control means brings the X-ray imaging mechanisms close to each other while bringing the X-ray imaging mechanisms into contact with each other while referring to the information on the relative positional relationship of each X-ray detector calculated by the positional relationship calculation means. It is preferable that the X-ray imaging system movement and the X-ray detector moving means are controlled so as to move in an avoiding direction.

  By configuring as described above, the above-described invention can be suitably implemented.

  The positional relationship calculation means calculates information on the relative positional relationship between the X-ray detectors using an algorithm that calculates the minimum distance between the adjacent X-ray imaging mechanisms and the X-ray detectors. It is preferable to constitute (claim 5).

  In the X-ray imaging apparatus of the present invention, each X-ray tube has an aperture for adjusting the X-ray irradiation area to the X-ray irradiation target, and when the X-ray detectors approach each other, the X-ray irradiation target is interested. A diaphragm adjusting unit that adjusts the diaphragm so that only the minimum region of the region is irradiated with X-rays, and the positional relationship calculating unit adjusts the irradiation region by the diaphragm adjusting unit so that the X-rays are detected by the detection surface of the X-ray detector. It is preferable that the information of the relative positional relationship which becomes the minimum space | interval which X-ray detection does not contact is calculated while being detected within (Claim 6).

  According to this configuration, by narrowing down the X-ray irradiation area, a plurality of irradiated X-rays pass through the region of interest, and an opening formed by the adjacent transmitted X-rays starting from this region of interest and facing each X-ray detector. The angle can be further reduced. That is, it is possible to reduce the dead space when performing simultaneous imaging using a plurality of X-ray imaging mechanisms.

  According to the X-ray imaging apparatus of the present invention, the transmitted X-ray is detected by the X-ray detector while keeping the X-ray imaging mechanism and the approaching object close to each other and keeping the distance from contacting each other. Can do. That is, since the X-ray imaging mechanism can be brought closer to the object as compared with the conventional apparatus, a dead space where transmitted X-rays cannot be detected can be minimized.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, an X-ray fluoroscopic imaging apparatus will be described as an example of a medical X-ray imaging apparatus.

  FIG. 1 is a perspective view showing an overall configuration of an X-ray fluoroscopic apparatus according to an embodiment, and FIG. 2 is a block diagram showing the overall configuration.

  As shown in FIG. 1, the X-ray fluoroscopic apparatus of the present embodiment includes an X-ray tube 1 for X-ray irradiation and a flat panel X-ray detector (hereinafter referred to as an X-ray detector for transmission X-ray detection). (Hereinafter simply referred to as “FPD”) 2 is a floor-installed first X-ray imaging mechanism 4 which is disposed opposite to both ends of a supporting C-shaped arm 3, an X-ray tube 5 for X-ray irradiation, and transmission X-ray detection FPD6, which is an X-ray detector for use, is provided with two sets of X-ray imaging mechanisms of a ceiling traveling type second X-ray imaging mechanism 8 disposed opposite to both ends of a supporting C-arm 7. The FPDs 2 and 6 have a quadrangular shape, which is larger than the outer shape of the holding portion of each of the C-type arms 3 and 7 held, and protrudes from the C-type arms 3 and 7.

  Further, X-ray imaging system moving mechanisms 9 (17, 18) for moving the X-ray imaging mechanisms 4 and 8 according to a common position coordinate system with a mechanical center point (isocenter) of the apparatus as a reference point are provided. The subject M on the top 10 is imaged by moving the X-ray imaging mechanisms 4 and 8 by the X-ray imaging system moving mechanism 9 to change the current positions of the X-ray imaging mechanisms 4 and 8, respectively. This is an apparatus of a double imaging mechanism system configured such that the direction (imaging direction) or position (imaging position) at the time of performing can be set for each of the X-ray imaging mechanisms 4 and 8 according to the imaging purpose.

  The position coordinate system having the origin (reference point) of the isocenter Q of the apparatus that determines the current positions of the first and second X-ray imaging mechanisms 4 and 8 is X in the longitudinal (vertical) direction of the top 10 and short in the top 3. XYZ Cartesian coordinates where Y is the hand (lateral) direction and Z is the vertical direction. The top plate 10 is also configured such that the current position is determined according to the XYZ orthogonal coordinates common to both the X-ray imaging mechanisms 4 and 8, and the top plate moving mechanism 11 is moved in each of the X, Y, and Z directions. It has become.

  Further, as shown in FIG. 2, the embodiment apparatus includes a first image monitor 12 that displays an X-ray fluoroscopic image or an X-ray image of the subject M imaged by the first X-ray imaging mechanism 4, and a second X-ray. And a second image monitor 13 for displaying an X-ray fluoroscopic image or an X-ray image of the subject M imaged by the imaging mechanism 8.

  Further, when performing the X-ray imaging, the embodiment apparatus moves the top plate 10 on which the subject M is placed by the top plate moving mechanism 11 to move the subject M between the X-ray tubes 1 and 5 and the FPDs 2 and 6. After being arranged between them, the X-ray imaging system moving mechanism 9 moves the first and second X-ray imaging mechanisms 4 and 8 respectively to set the imaging direction or imaging position according to the imaging purpose, X-rays are irradiated from the X-ray tubes 1 and 5 onto the subject M on the top 10 in accordance with 15 control. At the same time, the X-ray detection signals output from the FPDs 2 and 6 are processed by the signal processing unit 16 at the subsequent stage to create an X-ray fluoroscopic image or an X-ray image, and are displayed on the screens of the first and second image monitors 12 and 13. It is configured to be displayed.

  Hereinafter, the configuration of each part of the X-ray fluoroscopic apparatus according to the present embodiment will be described in detail.

  The X-ray imaging system moving mechanism 9 further includes a first imaging system moving mechanism 17 that moves the first X-ray imaging mechanism 4 and a second imaging system moving mechanism 18 that moves the second X-ray imaging mechanism 8. The system moving mechanisms 17 and 18 move the X-ray imaging mechanisms 4 and 8 according to the control of the imaging system movement control unit 19. The imaging system movement control unit 19 plays a function of the movement mechanism control means of the present invention. That is, the movement mechanism control means of the present invention is configured in cooperation with the detector movement control unit 28 described later.

  The first imaging system moving mechanism 17 moves the first X-ray imaging mechanism 4 by rotating or translating the C-arm 3. As the first X-ray imaging mechanism 4 moves, the current position of the first X-ray imaging mechanism 4 changes.

  As the rotational movement of the C-type arm 3 by the first imaging system moving mechanism 17, for example, the C-type arm 3 rotates around the isocenter Q in the longitudinal direction of the arm and rotates in the direction indicated by the arrow RA along the bending of the arm. Slide rotation and sagittal rotation in which the C-type arm 3 rotates in the direction indicated by the arrow RB with the axis 17b of the support shaft 17a supporting the center of the C-type arm 3 from the back so that the axis 17b always passes through the isocenter Q. There is.

  In both the case of slide rotation and sagittal rotation, the angle of the X-ray axis 20 connecting the center of the X-ray tube 1 and the center of the FPD 2 changes with the rotation of the C-arm 3, and the imaging direction changes. In the slide rotation and sagittal rotation, the direction in which the angle of the X-ray axis 20 changes is different by 90 °, so that the photographing direction can be adjusted.

  Further, the parallel movement of the C-arm 3 by the first imaging system moving mechanism 17 includes a horizontal movement in which the entire arm moves in parallel in the direction indicated by the arrow (X direction or Y direction). In the case of the first imaging system moving mechanism 17, three holding blocks 17A to 17C are linked and connected in a stacked manner, and the horizontal movement in the X and Y directions is performed by the three holding blocks 17A to 17C. It is performed by appropriately combining the rotation indicated by ~ RF. The imaging position can be adjusted by the parallel movement of the position of the X-ray axis 20 in the same direction as the C-arm 3 moves horizontally.

  Further, the rotation amount in the directions of arrows RA and RB and the rotation amount in the directions of arrows RD to RF (corresponding to the parallel movement amount in the direction of arrow RC) by the first imaging system moving mechanism 17 are detected by an appropriate sensor (not shown). At the same time, the detection result is fed back as information indicating the current position of the first X-ray imaging mechanism 4 to the imaging system movement control unit 19 and other information-necessary parts on the control system side to be notified.

  Returning to FIG. 2, the first imaging system moving mechanism 17 includes a first detector moving mechanism 26 that translates the FPD 2 provided at the tip of the C-arm 3 on the holding plane. A specific operation will be described in detail. The first detector moving mechanism 26 corresponds to the X-ray detector moving mechanism of the present invention.

  The second imaging system moving mechanism 18 moves the second X-ray imaging mechanism 8 by rotating or translating the C-arm 7. As the second X-ray imaging mechanism 8 moves, the current position of the second X-ray imaging mechanism 8 changes.

  As the rotational movement of the C-type arm 3 by the second imaging system moving mechanism 18, for example, as shown in FIG. 1, the C-type arm 7 moves around the isocenter Q in the longitudinal direction of the arm, and moves along the curve of the arm. A slide rotation that rotates in the direction indicated by Ra and a C type in the direction indicated by the arrow Rb with the axis 18b of the support shaft 18a supporting the center of the C type arm 7 from behind so that the axis 18b always passes through the isocenter Q. There is sagittal rotation in which the arm 7 rotates.

  In both the case of slide rotation and sagittal rotation, the angle of the X-ray axis 21 connecting the center of the X-ray tube 5 and the center of the FPD 6 changes with the rotation of the C-arm 7, and the imaging direction changes. In the slide rotation and sagittal rotation, the direction in which the angle of the X-ray axis 21 changes is different by 90 °, so that the photographing direction can be adjusted.

  Further, the parallel movement of the C-arm 7 by the second imaging system moving mechanism 18 includes a horizontal movement that moves parallel to the direction indicated by the arrow Rc, that is, the X direction. Specifically, a carriage 18A in which the C-arm 7 is suspended from the ceiling via a support shaft 18a is disposed on a rail 18B, 18B laid on the ceiling so as to extend in the X direction. As the carriage 18A travels along the rails 18B and 18B, the C-arm 7 is configured to move horizontally in the X direction. The photographing position can be adjusted by the parallel movement of the position of the X-ray axis 21 in the X direction as the C-arm 7 moves horizontally.

  Further, the amount of rotation in the directions of arrows Ra and Rb and the amount of parallel movement in the direction of arrow Rc by the second imaging system moving mechanism 18 are detected by an appropriate sensor (not shown), and the detection result is obtained by the second X-ray imaging mechanism 8. Information indicating the current position is fed back to the imaging system movement control unit 19 and other information-necessary parts on the control system side to be notified.

  Further, in the case of the second X-ray imaging mechanism 8, the C-type arm 7 is formed in such a manner that only the hands 7A and 7B at both ends of the arm expand and contract in parallel in the directions indicated by the arrows Rd and Re, that is, in the Z direction. The arrangement state of the X-ray tube 5 and the FPD 6 on the arm 7 is changed, and the Z-direction imaging position (imaging mode) can be finely adjusted. Changes in the deployment status of the X-ray tube 5 and the FPD 6 are also made in accordance with XYZ orthogonal coordinates, and the parallel movement amounts of the hands 7A and 7B are detected by an appropriate sensor (not shown). The change amount of the deployment status of the FPD 6 is configured to be fed back to the imaging system movement control unit 19 and other information-necessary portions on the control system side.

  The second imaging system moving mechanism 18 includes a second detector moving mechanism 27 that translates the FPD 6 provided at the tip of the C-arm 7 on the holding plane. A specific operation will be described in detail. The second detector moving mechanism 27 corresponds to the X-ray detector moving mechanism of the present invention.

  Further, in the case of the first and second X-ray imaging mechanisms 4 and 8, the X-ray tubes 1 and 5 are disposed in a fixed state on the C-type arms 3 and 7. The FPDs 2 and 6 are disposed on the C-shaped arms 3 and 7 so as to be reciprocally movable along the X-ray axes 20 and 21. That is, by moving the FPDs 2 and 6 along the directions of the X-ray axes 20 and 21, the magnification of the transmitted X-ray image projected on the X-ray detection surface of the FPDs 2 and 6 can be changed to adjust the imaging magnification. It has a configuration. The amount of movement of the FPDs 2 and 6 is also detected by an appropriate sensor (not shown), and the detection result is used as information indicating the current position of the FPDs 2 and 6 to information-necessary portions on the control system side such as the imaging system movement control unit 19. It is configured to be notified by feedback.

  The main control unit 22 of the embodiment apparatus includes an irradiation control unit 15 that controls X-ray irradiation by the X-ray tubes 1 and 5 according to the input operation by the operation unit 23 and the progress of X-ray imaging, and the first control unit 22. , An imaging system movement control unit 19 that controls the second imaging system movement mechanisms 17 and 18, a detector movement control unit 28 that controls the first and second detector movement mechanisms 26 and 27 that translate the FPDs 2 and 6, Alternatively, it is configured to send necessary commands and data to the top plate movement control unit 14 that controls the top plate moving mechanism 11. The detector movement control unit 28 serves as one function of the movement mechanism control means of the present invention.

  Further, the X-ray fluoroscopic apparatus according to the present embodiment further includes the X-rays including the FPDs 2 and 6 in order to avoid contact between the first and second X-ray imaging mechanisms 4 and 8 and / or the FPDs 2 and 6. A shape data registration unit 24 for registering 3D model outline data corresponding to the 3D outline shape of the imaging mechanisms 4 and 8, and each X based on the current position of each X-ray imaging mechanism 4 and 8 and the 3D model outline data. A positional relationship calculation unit 25 that calculates the relative positional relationship information of the line imaging mechanisms 4 and 8 in real time, and the imaging system movement control unit 19 and the detector movement control unit 28 are calculated by the positional relationship calculation unit 25. Operation control of the first and second imaging system moving mechanisms 17 and 18 and the first detector moving mechanisms 26 and 27 is performed in consideration of the relative positional relationship information between the X-ray imaging mechanisms 4 and 8 and the FPDs 2 and 6. It is configured so that. The shape data registration unit 24 corresponds to the shape data registration unit of the present invention, and the positional relationship calculation unit 25 corresponds to the positional relationship calculation unit.

  In the shape data registration unit 24, three-dimensional model outline data corresponding to the three-dimensional outline shapes of the X-ray imaging mechanisms 4 and 8 are registered in advance by the following process.

  First, three-dimensional model outline data in STL (Standard Triangle Language) format representing a shape substantially similar to the three-dimensional outline shape of the first and second imaging system moving mechanisms 17 and 18 is prepared. In the case of STL format data, since it is a format that represents a desired three-dimensional shape with a collection of triangles, the three-dimensional model outline data is held as position coordinates on the three-dimensional coordinates of all three vertices of each triangle. As a result, it is possible to represent the 3D model outline corresponding to the 3D outline of both X-ray imaging mechanisms 4 and 8 with a relatively small amount of data. The STL format three-dimensional model outline data is, for example, first and second imaging system moving mechanisms 17 and 18 created when designing the first and second imaging system moving mechanisms 17 and 18 including the FPDs 2 and 6. It is possible to easily create three-dimensional CAD data that accurately represents a shape similar to the outer shape of the image by applying an STL data conversion technique.

  Next, the 3D model outline data in STL format is converted into data in VOXEL (Volume Pixel) format. As shown in FIG. 3, the VOXEL format data conversion is performed by a cube or a rectangular parallelepiped parent that is set so that the existing area of the data is completely combined when the 3D model outline data in the STL format is represented in the 3D virtual space. A minimum box obtained by dividing the box Va into cubes or rectangular parallelepiped child boxes Vb1 and Vb2, grandchild boxes Vc1 to Vc4, great-grandchild boxes Vd1 to Vd8,... This corresponds to data inclusion information indicating whether or not dimension model outline data is contained. When the size of the minimum box is changed to the actual size of the first and second imaging system moving mechanisms 17 and 18, for example, a cube of about 1 cm square is obtained.

  Whether or not each minimum box contains 3D model outline data is determined by repeatedly determining whether or not the box contains 3D model outline data at each stage. At that time, for a box that is determined not to contain 3D model outline data at a certain stage (no), a box that does not contain data will not contain data no matter how many pieces it is divided. It is possible to quickly decide as “no” all.

  Subsequently, the data in the VOXEL format is converted into BSP (Binary separated partition) tree data. Contrary to the case of FIG. 3, the data conversion to BSP tree data is equivalent to collecting the minimum box accompanied by the data content information of the final division stage into the original parent box as shown in FIG. To do. That is, in the case of BSP tree data, the three-dimensional outer shape of the first and second X-ray imaging mechanisms 4 and 8 is represented by a collection of boxes accompanied by data content information. The three-dimensional model outline data in the BSP tree format is registered in the shape data registration unit 24 in advance.

  Note that the 3D model outline data need not represent all of the 3D outlines of the X-ray imaging mechanisms 4 and 8, and data may be omitted from places where there is no possibility of contact. In the case of the embodiment apparatus, it is more effective to omit the data where there is no possibility of contact because the calculation processing load for calculating the information on the relative positional relationship can be reduced.

  The positional relationship calculation unit 25 is based on the current positions of the X-ray imaging mechanisms 4 and 8 including the FPDs 2 and 6 and the three-dimensional model outline data registered in the shape data registration unit 24. Information on the relative positional relationship between the eight objects is calculated in real time using an algorithm for determining whether or not these objects are in a positional relationship where the objects are in contact with each other. Specifically, the two parent boxes of the 3D model outline data in the BSP tree format corresponding to the outline shapes of the X-ray imaging mechanisms 4 and 8 are transferred to the movements of the X-ray imaging mechanisms 4 and 8 in the virtual three-dimensional space. And rotate and translate based on the current position. Then, the two parent boxes of the three-dimensional model outline data are always arranged in the same manner as the X-ray imaging mechanisms 4 and 8 in the virtual three-dimensional space, and the outer surfaces of the X-ray imaging mechanisms 4 and 8 where contact occurs. Indicates the facing situation.

  Next, when two parent boxes are in contact with each other, the parent box of the three-dimensional model outline data is divided to determine whether or not the smallest boxes are in contact with each other. In this embodiment, when checking the presence or absence of contact, a predetermined virtual contact distance that can prevent contact is set in advance in consideration of the braking distance of each of the imaging system moving mechanisms 17 and 18. The distance between the minimum box of the 3D model outline data of the first imaging system moving mechanism 17 and the minimum box of the 3D model outline data of the second imaging system moving mechanism 18 is calculated. If the result is less than the virtual contact distance, it is determined that there is contact, and if it is equal to or greater than the virtual contact distance, it is determined that there is no contact. This distance calculation / determination process is repeated between all of the minimum boxes (containing data) with data content information.

  The determination result of the presence or absence of contact thus obtained is output to the imaging system movement control unit 19 as information on the relative positional relationship between the X-ray imaging mechanisms 4 and 8. The determination result of the presence / absence of contact as information on the relative positional relationship is based on the current positions of the 2X-ray imaging mechanisms 4 and 8 that are moved according to a common position coordinate system with the isocenter Q of the apparatus as a reference point. So it becomes extremely accurate.

  In the process of checking the presence / absence of the contact, the positional relationship calculation unit 25 further includes a moving direction, a moving trajectory, and a moving distance of the FPD for avoiding the contact when the contact outer surface includes at least one of the FPDs 2 and 6. Is calculated.

  For example, in the case of the apparatus according to the present embodiment, the positional relationship calculation unit 25 divides and uses the FPD and the contact target object in the order of the parent box to the minimum box of the 3D model outline data of the contact object, and makes contact between both objects in the virtual 3D space The movement distance of the FPD that can avoid the above is calculated. That is, the movement direction and movement trajectory of the FPD that is likely to come into contact with the object are calculated. Then, in the virtual three-dimensional space, the minimum box of the three-dimensional model outline data of the FPD and the contact object is registered in advance in the shape data registration unit 24 while moving along the movement trajectory between the objects previously calculated. A simulation for moving the minimum box of the FPD in the contact avoidance direction within the range of the distance that can be translated on the holding plane is executed by calculation. By this simulation, the presence or absence of contact avoidance and the movement distance of the FPD that can avoid contact are obtained.

  As described above, when the first X-ray imaging mechanism 4 and the second X-ray imaging mechanism 8 are not in contact with each other by the positional relationship calculation unit 25, the imaging system movement control unit 19 does not take any special retreat measures. In addition, even if both X-ray imaging mechanisms 4 and 8 are likely to contact each other, if the contact can be avoided by moving the FPDs 2 and 6 in the contact avoidance direction, the first or second imaging system movement inspection mechanism At least one of the FPDs 2 and 6 that are likely to come into contact with the detector moving mechanisms 26 and 27 is moved in the contact avoidance direction while the actuators 17 and 18 are operated and brought close to each other. Further, when the positional relationship calculation unit 25 determines that the contact between the X-ray imaging mechanisms 4 and 8 cannot be avoided and the contact cannot be avoided even by the movement of the FPDs 2 and 6, the positional relationship calculation unit 25. Is configured to output to the imaging system movement control unit 19 a control signal for immediately stopping the movement of at least one of the two X-ray imaging mechanisms 4 and 8 in operation.

  In the case of the apparatus according to the present embodiment, when the positional relationship calculation unit 25 determines that both the X-ray imaging mechanisms 4 and 8 are in contact, the moving X-ray imaging mechanism is not stopped. The other X-ray imaging mechanism that is likely to come into contact with the moving X-ray imaging mechanism may be retracted, and the moving X-ray imaging mechanism may be moved as it is.

  Further, the positional relationship calculation unit 25 adjusts the X-ray accompanying the change in the deployment state of the X-ray tube 5 and the FPD 6 by fine adjustment by extending and contracting only the hands 7A and 7B at both ends of the C-type arm 7 in order to adjust the imaging magnification. It is configured to calculate information on the relative positional relationship between the X-ray imaging mechanisms 4 and 8 taking into account the change in the outer shape of the imaging mechanism 8. If there is a change in the outer shape of the second X-ray imaging mechanism 8 due to a change in the deployment status of the X-ray tube 5 and the FPD 6 on the C-arm 7, the facing condition between the outer surfaces of both X-ray imaging mechanisms changes, An error occurs when calculating positional information. Therefore, information on the relative positional relationship between the X-ray imaging mechanisms 4 and 8 is calculated by taking into account the change in the outer shape of the X-ray imaging mechanism 8 accompanying the change in the deployment status of the X-ray tube 5 and the FPD 6.

  In the case of the embodiment apparatus, the BSP tree format three-dimensional model outline data of the X-ray imaging mechanism 8 is divided and registered in the X-ray tube 5 and the FPD 6 and the C-arm 7 respectively, and the X-ray tube 5 and the FPD 6 are arranged. According to the change of the situation, the boxes constituting the three-dimensional model outline data of the X-ray tube 5 and the FPD 6 are respectively moved, and then the presence or absence of contact is determined.

  Further, in the case of the embodiment apparatus, a configuration for reliably avoiding contact between the first and second X-ray imaging mechanisms 4 and 8 and the top plate 10 is provided. In other words, the shape data registration unit 24 registers the 3D model outline data corresponding to the 3D outline shape of the top board 10 in the same process as that of the X-ray imaging mechanism. That is, the positional relationship calculation unit 25 uses the presence or absence of contact between the X-ray imaging mechanisms 4 and 8 and the top 10 as information on the relative positional relationship based on the current position and the three-dimensional model outline data. It is configured to calculate in the same process as in the above. The imaging system movement control unit 19 is configured to control the first and second imaging system movement mechanisms 17 and 18 in consideration of the information on the relative positional relationship between the X-ray imaging mechanisms 4 and 8 and the top 10. Yes.

  In the embodiment apparatus, the information on the relative positional relationship between the X-ray imaging mechanisms 4 and 8 and the top board 10 is also output to the top board movement control unit 14. It is also configured to control the top plate moving mechanism 11 while taking into account information on the relative positional relationship between the X-ray imaging mechanisms 4 and 8 and the top plate 10. However, since the top plate 10 is normally not moved after it is set at a reference position, the top plate movement control unit 14 is usually connected between the X-ray imaging mechanisms 4 and 8 and the top plate 10. The configuration may not be such that relative positional relationship information is output.

  The imaging system movement control unit 19 and the top board movement control unit 14 determine that the contents of the signals output from the positional relationship calculation unit 25 are in contact with the X-ray imaging mechanisms 4 and 8 and the top board 10. In this case, it is configured to immediately output a control signal instructing to stop moving the X-ray imaging mechanisms 4 and 8 and the top 10.

  In the case of the apparatus according to the present invention, when the information content indicates that there is a contact, the object that obstructs the movement of the moving first and second imaging system moving mechanisms 17 and 18 or the top plate 10 is retracted and moved. The X-ray imaging system mechanisms 17 and 18 or the top plate 10 may be moved as they are.

  Next, contact avoidance processing during movement of the first and second X-ray imaging mechanisms 4 and 8 in the above-described embodiment apparatus will be described based on the flowchart shown in FIG. 5 and FIGS.

  In addition, as shown in FIG. 6, in a state where both the X-ray imaging mechanisms 4 and 8 are on the same plane at the same time as the X-ray axes 20 and 21 of the X-ray imaging mechanisms 4 and 8 both pass through the isocenter Q. One first X-ray imaging mechanism 4 is stopped (point A). The case where the other second X-ray imaging mechanism 8 is moved to the point C by slidingly rotating the C-arm 7 from the current position (point B) will be described as an example.

[Step S1] As the slide rotation of the C-arm 7 starts, the second X-ray imaging mechanism 8 starts to move in the direction indicated by the arrow rb.

[Step S2] In conjunction with the start of movement of the second X-ray imaging mechanism 8, the current positions of both the X-ray imaging mechanisms 4 and 8 are detected according to the operating conditions of the first and second imaging system moving mechanisms 17 and 18. And output to the positional relationship calculation unit 25.

[Step S3] The positional relationship calculation unit 25 makes contact between the X-ray imaging mechanisms 4 and 8 based on the current positions of the X-ray imaging mechanisms 4 and 8 and the parent box of each three-dimensional model outline data. Judgment processing to predict the presence or absence of.

[Step S4] If the determination result by the positional relationship calculation unit 25 is the information content that there is no contact, the process returns to Step S1 again until the projection center position of the X-rays emitted from the X-ray tube 1 reaches point C. The processing from step S2 is repeated while continuing the slide rotation of the arm 7. If the calculation result is information content that there is contact, the process proceeds to step S5.

[Step S5] The positional relationship calculation unit 25 identifies the contact object based on the parent box of the three-dimensional model outline data. At this time, when the FPDs 2 and 6 provided in the respective X-ray imaging mechanisms 4 and 8 are not included in the contact object, the process proceeds to step S6, and at least one of the FPDs 2 and 6 is included in the contact object. If so, the process proceeds to step S7.

[Step S6] A signal indicating that the contact object is a part other than the FPDs 2 and 6 is output from the positional relationship calculation unit 25 to the imaging system movement control unit 19. The imaging system movement control unit 19 that has received this signal stops the second imaging system movement mechanism 18 so as to stop at a position where the approach distance between the X-ray imaging mechanisms 4 and 8 is a preset minimum distance for avoiding contact. To control the operation. And a contact avoidance process is complete | finished when the movement of the 2nd X-ray imaging mechanism 8 stops.

[Step S7] The positional relationship calculation unit 25 determines the possibility of contact avoidance when the movement control of the FPD that is the contact object is performed. For this determination, the movement direction of the FPD and the contact object and the movement trajectory of the FPD and the object until reaching the movement destination are calculated by calculation. Then, in the virtual three-dimensional space, a simulation is performed in which the parent box of the three-dimensional model outline data of the contact object is moved along the movement trajectories of both the contact objects calculated and obtained. In the process of this simulation, when the parent boxes come into contact with each other, it is further divided into the minimum boxes and the contact part is specified. When the contact portion of the FPD is specified by this simulation, the contact avoidance direction of the FPDs 2 and 6 in the virtual three-dimensional space corresponding to the holding plane of the C-arm is obtained from the specification result and the moving direction.

  When the avoidance direction of the FPDs 2 and 6 is obtained, the positional relationship calculation unit 25 executes a contact avoidance simulation and determines whether or not there is a contact. In the case of the present embodiment, as shown in FIG. 7, the FPD 6 is slid in the direction opposite to the sliding rotation direction of the C-type arm 7 while the C-type arm 7 is slid and rotated in the C-point direction, and the FPD 2 is opposite to the FPD 6 Slide in the direction. In other words, the C-type arm 7 is brought close to the other first X-ray imaging mechanism 4 and the FPDs 2 and 6 are relatively separated within a range in which the C-type arm 7 can move on the holding plane of the C-type arms 3 and 7. Move.

  Further, in the process of this simulation, the movement distance that can avoid contact between the FPDs 2 and 6 is obtained while all the transmitted X-rays are projected on the detection surfaces of the FPDs 2 and 6.

  That is, in this simulation, when it is determined that the contact between the two FPDs 2 and 6 can be avoided, the positional relationship calculation unit 25 determines the position where the FPDs 2 and 6 are not in contact with each other and the second X-ray at that time. The stop position of the imaging mechanism 8 is calculated. Then, the calculation result is transmitted to the imaging system movement control unit 19 and the detector movement control unit 28, and the process proceeds to step S9.

  On the contrary, if it is determined as a result of the simulation that the contact between the two FPDs 2 and 6 cannot be avoided, the positional relationship calculation unit 25 is the position information at which the second X-ray imaging mechanism 8 can stop at a distance where the FPDs 2 and 6 do not contact each other. Is transmitted to the imaging system movement control unit 19, and the process proceeds to step S8.

[Step S8] The imaging system movement control unit 19 controls the operation of the second imaging system movement mechanism 18 according to the information of the received signal from the positional relationship calculation unit 25, and forces the second X-ray imaging mechanism 8 at a predetermined position. Stop. With this process, the contact avoidance process between the FPDs 2 and 6 ends. In this case, since the C-arm 7 has not reached the point C of the destination, the FPD 6 cannot detect the transmitted X-rays irradiated from the X-ray tube 5 and transmitted through the subject M.

[Step S9] The imaging system movement control unit 19 decelerates a motor (not shown) that rotates the C-arm 7 of the second X-ray imaging mechanism 8 in accordance with the information of the received signal from the positional relationship calculation unit 25, and performs predetermined processing. Stop at the position of. Until the C-arm 7 is stopped, the detector movement control unit 28 controls the operation of both detector movement mechanisms 26 and 27 to move the FPDs 2 and 6 relative to each other as shown in FIG. Stop in place. Therefore, contact between the FPDs 2 and 6 is avoided. At the same time, the FPD 6 detects transmitted X-rays irradiated from the X-ray tube 5 and transmitted through the subject M. This is the end of the avoidance operation of the apparatus according to the present embodiment.

  As described above in detail, according to the embodiment apparatus, even when the X-ray imaging mechanisms 4 and 8 are brought into contact with each other as the X-ray imaging mechanisms 4 and 8 are moved, the contact is made. If the target object is FPD 2 or 6 that protrudes from the outer shape of the holding part of the C-shaped arms 3 and 7, the FPD 2 and 6 transmit X-rays by moving the FPD 2 and 6 in a direction that avoids contact on the holding plane. The contact can be avoided while detecting.

  At this time, by moving the FPDs 2 and 6 relatively apart from each other, the FPDs 2 and 6 can detect transmitted X-rays by using the detection surfaces close to each other. Can be made smaller than the opening angle α of the conventional device shown in FIG. 9. That is, since both X-ray imaging mechanisms 4 and 8 can be brought closer to each other as compared with the conventional apparatus, it is possible to suppress a dead space in which imaging transmission X-rays cannot be detected.

The present invention is not limited to the above embodiment, and can be modified as follows.
(1) In the apparatus of the embodiment, the relative positional relationship information is calculated using an algorithm for determining whether or not the objects are in a positional relationship where the objects are in contact with each other. Also good.

  For example, a plurality of capacitive proximity sensors are provided on each side of the movable parts constituting the X-ray imaging mechanisms 4 and 8 such as the X-ray tubes 1 and 5, the FPDs 2 and 6, and the C-shaped arms 3 and 7. When the proximity sensor detects an approaching object, the positional relationship calculation unit 25 calculates the direction and distance in which the approaching object exists based on the change in capacitance. Then, based on the calculation result, the positional relationship calculation unit 25 calculates a moving direction and a moving distance that can avoid contact between the two X-ray imaging mechanisms 4 and 8 and the FPDs 2 and 6 that are contact objects. What is necessary is just to comprise.

(2) In the embodiment apparatus, the X-ray tube further includes a diaphragm for reducing the beam diameter, the beam diameter is reduced so that only the region of interest is irradiated with X-rays, and both the FPDs 2 and 6 are held flat. In a state where the FPDs 2 and 6 are relatively moved apart from each other, the transmission X-rays may be detected from the detection surfaces close to each other. According to this configuration, the opening angle α formed by the two transmitted X-rays can be further reduced, and the dead space in which the transmitted X-rays cannot be detected can be minimized.

(3) Although the apparatus according to the embodiment is configured to be equipped with a floor installation type and an overhead traveling type X-ray imaging mechanism, the X-ray imaging mechanism may be all floor installation type, or may be all overhead traveling type. It is also possible to use a floor traveling type.

(4) In the embodiment apparatus, the X-ray detector is an FPD, but an image intensifier (II tube) may be used as the X-ray detector.

(5) In the embodiment apparatus, the number of X-ray imaging mechanisms is two, but the number is not limited to two and may be three or more. In addition, the movement control of the FPDs 2 and 6 is not limited to the case where the FPDs are close to each other. Move controlled.

(6) Although the example device was a medical device, the device of the present invention can also be applied to an industrial device.

(7) In the embodiment device, the top plate 10 is movable. However, the device of the present invention can be applied to a configuration in which the top plate 10 does not move.

It is a perspective view which shows the whole structure of the X-ray fluoroscopic apparatus of an Example. It is a block diagram which shows the whole structure of the X-ray fluoroscopic imaging apparatus of an Example. It is a schematic diagram for demonstrating the format of the three-dimensional model external shape data of a VOXEL format. It is a schematic diagram for demonstrating the format of the three-dimensional model external shape data of a BSP tree format. It is a flowchart which shows the contact avoidance process in an Example apparatus. It is a schematic diagram which shows the movement condition of the X-ray imaging mechanism in an Example apparatus. It is a schematic diagram which shows the movement condition of the X-ray imaging mechanism in an Example apparatus. It is a schematic diagram which shows the movement condition of the X-ray imaging mechanism in an Example apparatus. It is a schematic diagram which shows two sets of X-ray imaging mechanisms in the conventional X-ray imaging mechanism of a double imaging mechanism system.

Explanation of symbols

1, 5 ... X-ray tube 2, 6 ... FPD (X-ray detector)
3, 7 ... C-arm (support arm)
DESCRIPTION OF SYMBOLS 4 ... 1st X-ray imaging mechanism 8 ... 2nd X-ray imaging mechanism 9 ... X-ray imaging system moving mechanism 10 ... Top plate 17 ... 1st imaging system moving mechanism 18 ... 2nd imaging system moving mechanism 19 ... Imaging system movement control part 24 ... shape data registration unit 25 ... positional relationship calculation unit 26 ... first detector movement mechanism 27 ... second detector movement mechanism 28 ... detector movement control unit M ... subject Q ... isocenter

Claims (6)

An X-ray tube for X-ray irradiation and an X-ray detector for detecting transmitted X-rays are provided with an X-ray imaging mechanism disposed opposite to both ends of a support arm, and X for moving the X-ray imaging mechanism In an X-ray imaging apparatus equipped with a line imaging system moving mechanism,
An X-ray detector moving mechanism for translating an X-ray detector arranged on an arm of the X-ray imaging mechanism on a holding plane;
Detecting means for detecting that the X-ray imaging mechanism is moving and detecting that the object is approaching and outputting a detection signal;
When a signal is output from the detection means, at least the X-ray detector is moved in parallel on the holding plane of the arm so as to move away from the approaching object while bringing the X-ray imaging mechanism close. A moving mechanism control means for controlling the operation of the X-ray detector moving mechanism;
An X-ray imaging apparatus comprising: The X-ray imaging apparatus according to claim 1,
The object is an X-ray imaging mechanism including the X-ray tube and an X-ray detector,
When at least one of the X-ray imaging mechanisms is moving and the detection means detects that the X-ray imaging mechanism is approaching another X-ray imaging mechanism, the movement mechanism control means is based on the detection signal. While moving the X-ray imaging mechanisms close to each other, the X-ray detector is translated on the holding plane of the arm so that at least one X-ray detector is separated from other approaching X-ray imaging mechanisms. The X-ray imaging apparatus is configured to control the operation of the X-ray detector moving mechanism. The X-ray imaging apparatus according to claim 2,
The detection means includes shape data registration means for registering 3D model outline data corresponding to the 3D outline of each X-ray imaging mechanism;
Based on the current position of each X-ray imaging mechanism and the three-dimensional model outline data, distance information between the X-ray imaging mechanisms and the X-ray detectors, and the relative relationship between the X-ray imaging mechanisms and the X-ray detectors It is composed of positional relationship calculation means for calculating positional relationship information in real time,
The movement mechanism control means moves each X-ray imaging mechanism according to a common position coordinate system with a mechanical center point of the apparatus as a reference point, and the information calculated by the positional relationship calculation means. X-ray imaging characterized in that the X-ray detector moving means is operated and controlled so that the X-ray detector moves in a direction avoiding contact while bringing the X-ray imaging mechanisms close to each other in consideration of apparatus. The X-ray imaging apparatus according to claim 3,
The detection means is a capacitive proximity sensor,
The positional relationship calculating means calculates information on the relative positional relationship between the X-ray detectors in real time based on the capacitance change of each proximity sensor,
The moving mechanism control means makes the X-ray detection approaching while bringing the X-ray imaging mechanisms close to each other while taking into account information on the relative positional relationship of each X-ray detector calculated by the positional relation calculating means. The X-ray imaging apparatus characterized in that the operation of the X-ray detector moving means is controlled so that the instruments move in a direction to avoid contact. The X-ray imaging apparatus according to claim 3 or 4,
The positional relationship calculation means is configured to calculate information on the relative positional relationship between X-ray detectors using an algorithm that calculates a minimum distance between adjacent X-ray imaging mechanisms and X-ray detectors. X-ray imaging apparatus characterized by the above. The X-ray imaging apparatus according to any one of claims 3 to 5,
Each of the X-ray tubes includes a diaphragm for adjusting an X-ray irradiation area to an X-ray irradiation target,
A diaphragm adjusting means for adjusting the diaphragm so as to irradiate X-rays only to the minimum region of the region of interest of X-ray irradiation when the X-ray detectors approach each other;
The positional relationship calculating means adjusts the irradiation area by the diaphragm adjusting means, and detects the X-rays within the detection surface of the X-ray detector, but the relative positional relationship is the minimum interval at which the X-ray detections do not contact each other. An X-ray imaging apparatus characterized in that the information is calculated.

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