JP2013252291A - X-ray apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray apparatus which can accurately acquire actual positional discrepancy information, or the rotating angle of a rotating means at the time of fluoroscopy or photographing.SOLUTION: A correlation wherein positional discrepancy information (Δθ) by the backlash of a gear and the rotating direction of the gear immediately before the positional discrepancy information occurs are respectively correlated is stored in a table in advance. The positional discrepancy information (a discrepancy of the rotating angle Δθor Δθ) corresponding to the actual rotating direction of the gear is acquired as the actual positional discrepancy information in response to the actual rotating direction (Ror L) of the gear at the time of fluoroscopy or photographing, and the correlation. As a result, the actual positional discrepancy information can be acquired in response to the correlation, alternatively, the rotating angle of the rotating means (motor) at the time of fluoroscopy or photographing can accurately be acquired.

Description

  The present invention relates to an X-ray apparatus that performs fluoroscopy or imaging of a subject.

  Conventionally, this type of X-ray apparatus includes an image system including an X-ray tube and an X-ray detector, and a bed or a top plate that supports a subject. For example, the X-ray apparatus includes a curved C-arm that supports an X-ray tube at one end and an X-ray detector at the other end. In an X-ray apparatus provided with such a C-arm, a mechanical error occurs due to deflection of the C-arm or the like. Therefore, there is a technique for obtaining an error using a reconstructed image of a phantom having a plurality of wires arranged substantially parallel to the rotation center axis in order to suitably obtain and correct a mechanical error (for example, Patent Documents). 1).

JP 2005-58309 A

  However, even if an error is obtained using such a reconstructed image of the phantom, as shown in FIGS. 8A to 8C, the backlash of the gear g due to the mechanical structure, as shown in FIGS. Therefore, there is a problem that it is difficult to calculate an accurate rotation angle. Specifically, in order to move freely in the gear g / rack r meshing with each other, the gear g / rack r is provided with a gap shown in FIGS. This gap is called “backlash”. On the other hand, if there is no backlash as the gap, the gear g / rack r does not move freely and the driving force of the gear g cannot be transmitted to the rack r.

  For example, when the gear g and the rack r are rotated and stopped in the direction shown in FIG. 8B, the rack r is slightly rotated by the amount of backlash and stopped regardless of the stopping time. Similarly, when the gear g and the rack r are rotated in the reverse direction shown in FIG. 8C and stopped, the rack r is slightly rotated by the amount of backlash regardless of the stop time, and then stopped. As described above, the gear g or the rack r is displaced due to the backlash, so that the image system and the support means (the bed and the top plate) are displaced, so that the subject cannot be seen and photographed at the correct position. In this specification, since the rack also has teeth, the rack is also defined as a gear in a broad sense.

  The present invention has been made in view of such circumstances, and provides an X-ray apparatus capable of obtaining actual positional deviation information or accurately obtaining the rotation angle of the rotating means during fluoroscopy or imaging. For the purpose.

In order to achieve such an object, the present invention has the following configuration.
That is, the X-ray apparatus according to the present invention includes a rotation unit that drives at least one of the imaging system and the support unit that supports the subject by rotation of the gear, and the rotation unit rotates the gear at least. An X-ray apparatus that drives either one of the subject to perform fluoroscopy or imaging of the subject using the video system, and includes information on positional deviation due to backlash of the gear and rotation of the gear immediately before the positional deviation information is generated. And (A) a first calculation for obtaining actual positional deviation information based on the rotational direction of the actual gear and the correlation during fluoroscopy or photographing. Or (B) based on the actual positional deviation information obtained by the first calculation, It is rolling a second operation for obtaining the rotation angle of the unit which is characterized by comprising calculating means for performing together with the first computation.

  [Operation / Effect] According to the X-ray apparatus of the present invention, the correlation means for associating the positional deviation information due to the backlash of the gear with the rotational direction of the gear immediately before the positional deviation information is associated is stored. Is stored in advance. In order to create this correlation, it is preferable to detect positional deviation information by a highly accurate position detecting means or the like. Since this positional deviation information is associated with the rotation direction of the gear immediately before the positional deviation information has occurred, it can be obtained in advance as a correlation in which these are associated with each other. Using this correlation, the calculation means performs the following first calculation or second calculation together with the first calculation. In the case of (A), based on the actual rotation direction of the actual gear at the time of fluoroscopy or photographing and the above-described correlation, the position shift information corresponding to the rotation direction of the actual gear is the actual position shift information. It is obtained by performing one operation. On the other hand, in the case of (B), the rotation angle of the rotating means at the time of fluoroscopy or photographing is obtained by performing the second calculation based on the actual positional deviation information obtained by the first calculation. As a result, based on the above-described correlation, actual positional deviation information can be obtained, or the rotation angle of the rotation means during fluoroscopy or photographing can be accurately obtained.

In the X-ray apparatus according to the present invention, when the rotating means is rotating, the following configuration is preferable.
That is, in the above correlation, the positional deviation information during rotation of the rotation means and the rotation direction of the gear are associated with each other and stored in advance in the storage means, and the calculation means (A) at the time of fluoroscopy or photographing Based on the actual rotation direction of the gear and the above-described correlation, the first calculation for obtaining the actual positional deviation information during the rotation of the rotating means is performed, or (B) the actual rotation during the rotation determined by the first calculation It is preferable to perform the second calculation for obtaining the rotation angle of the rotating means at the time of fluoroscopic observation or photographing based on the positional deviation information together with the first calculation described above.

  When the rotating means is rotating, the positional deviation information during rotation of the rotating means is obtained, and the positional deviation information during rotation and the rotation direction of the gear are stored in the storage means in advance as correlations associated with each other. can do. In the case of (A), based on the actual gear rotation direction at the time of fluoroscopy or photographing and the above-described correlation, the positional deviation information corresponding to the actual gear rotation direction is the actual position during rotation of the rotating means. It is obtained by performing the first calculation as the deviation information. On the other hand, in the case of (B), based on the actual positional deviation information during rotation obtained by the first calculation described above, the rotation angle of the rotating means at the time of fluoroscopy or photographing during the rotation performs the second calculation. It is required by that.

Further, in the X-ray apparatus according to the present invention, when the rotating means is stopped, the following configuration is preferable.
That is, in the above-described correlation, the calculation unit stores in advance the above-described storage unit in association with the positional deviation information when the rotation unit is stopped and the rotation direction immediately before the gear is stopped. Alternatively, based on the actual rotation direction of the gear at the time of photographing and the above-described correlation, the first calculation for obtaining the actual positional deviation information when the rotating means is stopped is performed, or (B) is obtained by the first calculation. It is preferable to perform the second calculation for obtaining the rotation angle of the rotating means at the time of fluoroscopy at the time of stop or photographing based on the actual positional deviation information at the time of stop together with the first calculation.

  When the rotating means is stopped, the positional deviation information when the rotating means is stopped is obtained, and the positional deviation information when the rotating means is stopped is correlated with the rotation direction immediately before the gear stops. It can be stored in advance in the storage means. In the case of (A), positional deviation information corresponding to the rotation direction immediately before the actual gear stop is obtained based on the rotation direction immediately before the actual gear stop and the above-described correlation during fluoroscopy or photographing. It is calculated | required by performing a 1st calculation as position shift information at the time of a stop. On the other hand, in the case of (B), the rotation angle of the rotating means at the time of fluoroscopy at the time of stop or photographing is calculated based on the actual position shift information at the time of stop obtained by the above first calculation. It is required by doing.

  In the X-ray apparatus according to these inventions, the rotation direction of the rotation of the gear is determined based on the first calculation and the second calculation in the calculation means, and the rotation control is performed to the target rotation angle of the rotation means. It is even more preferable to provide control means for controlling the rotating means. Since the positional deviation information when the rotation means is rotated to the target rotation angle and stopped is stored in advance in the above correlation, the gear for controlling the target rotation angle based on the first calculation and the second calculation is stored. The target rotation angle can be determined, and as a result, the control means can control the rotation to the target rotation angle. Therefore, it is possible to control the rotating means so as to control the rotation to the target rotation angle without causing a positional shift.

  According to the X-ray apparatus of the present invention, the correlation that associates the positional deviation information due to the backlash of the gear and the rotational direction of the gear immediately before the positional deviation information is stored in the storage means in advance. In the case of (A), based on the rotation direction and correlation of the actual gear at the time of fluoroscopy or photographing, the position shift information corresponding to the rotation direction of the actual gear is the first calculation as the actual position shift information. It is required by doing. On the other hand, in the case of (B), the rotation angle of the rotating means at the time of fluoroscopy or photographing is obtained by performing the second calculation based on the actual positional deviation information obtained by the first calculation. As a result, based on the above-described correlation, actual positional deviation information can be obtained, or the rotation angle of the rotation means during fluoroscopy or photographing can be accurately obtained.

It is the side view which showed schematic structure of the X-ray apparatus provided with C arm which concerns on each Example. 1 is a block diagram of an image processing system in an X-ray apparatus according to Embodiments 1 and 2. FIG. FIG. 6 is a schematic diagram for explanation of performing a first calculation for obtaining positional deviation information during rotation with reference to the table according to the first embodiment. FIG. 10 is a schematic diagram for explanation of performing a first calculation for obtaining positional deviation information at a stop with reference to a table according to a second embodiment. 6 is a block diagram of an image processing system in an X-ray apparatus according to Embodiment 3. FIG. It is the side view which showed schematic structure of the X-ray apparatus which concerns on a modification. It is a block diagram of the image processing system in the X-ray apparatus which concerns on a modification. It is the schematic where it uses for description of backlash.

Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view illustrating a schematic configuration of an X-ray apparatus including a C-arm according to each embodiment, and FIG. 2 is a block diagram of an image processing system in the X-ray apparatus according to the first and second embodiments. is there. In the first embodiment, including later-described second and third embodiments, a top plate on which a subject is placed will be described as an example of support means.

  As shown in FIG. 1, the X-ray apparatus according to the first embodiment, including the second and third embodiments to be described later, performs fluoroscopy or imaging of the top plate 1 on which the subject M is placed and the subject M. A video system 2 and an image processing system 6 are provided as shown in FIG. The top plate 1 corresponds to the support means in this invention, and the video system 2 corresponds to the video system in this invention.

  First, the mechanism around the top plate 1 will be described with reference to FIG. A top plate drive unit (not shown) for driving the top plate 1 in parallel in the horizontal direction (for example, the x direction or the y direction in the figure) is provided. In addition, a top plate elevating unit (not shown) is provided that moves the top plate 1 up and down by parallel driving along the vertical direction (z axis in the drawing). The top plate driving unit and the top plate elevating unit are, for example, a motor (not shown), a gear (not shown) attached to the motor via a rotary shaft (not shown), and the gear 1 meshed with the gear. And a supported flat rack (not shown). In this case, the gear is rotated through the rotation shaft when the motor is driven to rotate. In conjunction with the rotation of the gear, the flat rack engaged with the gear changes the driving direction from the rotational direction to the straight traveling direction, and the top plate 1 moves in parallel with the flat rack in each direction.

  The top plate driving unit and the top plate lifting unit need not be configured with the gears described above. However, when the top plate driving unit is configured with the gear described above, the rotation error due to the backlash described above occurs, so that as will be described later, (A) actual positional deviation information, or (B) during fluoroscopy or photographing. What is necessary is just to obtain | require the rotation angle of a motor. In addition, when the top plate elevating unit for moving the top plate 1 up and down is configured with the above-described gear, the influence of gravity is more dominant than the backlash, so (A) actual positional deviation information, or (B) It is not necessary to obtain the rotation angle of the motor during fluoroscopy or shooting. Of course, it is also possible to combine both positional deviation information due to gravity and positional deviation information due to rotation error due to backlash.

  Next, the video system 2 will be described with reference to FIG. The video system 2 includes a base portion 21 installed on the floor (xy plane in the drawing), a C arm support portion 22 supported by the base portion 21, and a C arm supported by the C arm support portion 22. 23, an X-ray tube 24 supported at one end of the C arm 23, and a flat panel X-ray detector (FPD) 25 supported at the other end.

  In addition, a first video system drive unit 31 is provided that rotates the base unit 21 about the vertical axis (z axis in the figure) with respect to the floor surface. The first video system drive unit 31 includes a motor 32, a belt 33 that transmits the rotation of the motor 32, a gear box 34 that converts the rotation transmitted to the belt 33 into a rotation around the vertical axis, and a gear box 34. A gear 35 that transmits rotation about the vertical axis of the gear 35 and a gear 36 meshed with the gear 35 are provided. The gear 36 is fixed to the floor surface with a bearing (not shown) interposed. When the motor 32 is driven to rotate, the gear 36 rotates around the vertical axis via the belt 33, the gear box 34, and the gear 35. The rotation of the gear 36 causes the base portion 21 to rotate around the vertical axis with respect to the floor surface. Further, when the base unit 21 is rotated about the vertical axis by the first video system driving unit 31, the C arm support unit 22 supported by the base unit 21 is also rotated about the vertical axis, and C The C arm 23 supported by the arm support 22 also rotates around the vertical axis, and the X-ray tube 24 and the FPD 25 supported by the C arm 23 also rotate around the vertical axis. As described above, the motor 32 of the first video system driving unit 31 rotates the video system 2 having the X-ray tube 24 and the FPD 25 around the vertical axis by the rotation of the gear 35. The motor 32 including the motors 42 and 54 described later corresponds to the rotating means in the present invention, and the gear 35 including the gear 45 described later corresponds to the gear in the present invention.

  In addition, a second video system driving unit 41 is provided for rotating the C arm support unit 22 around the axis of the body axis of the subject M (x axis in the figure) with respect to the base unit 21. The second video system drive unit 41 includes a motor 42, a belt 43 that transmits the rotation of the motor 42, a gear box 44 that converts the rotation transmitted to the belt 43 into a rotation around the axis of the body axis, and a gear box A gear 45 for transmitting rotation around the axis of the body axis from 44 and a gear 46 meshed with the gear 45 are provided. The gear 46 is fixed to the base portion 21 with a bearing (not shown) interposed. When the motor 42 is driven to rotate, the gear 46 rotates around the axis of the body axis via the belt 43, the gear box 44, and the gear 45. By the rotation of the gear 46, the C-arm support portion 22 rotates around the axis of the body axis with respect to the base portion 21. Further, the C arm 23 supported by the C arm support portion 22 also rotates around the axis of the body axis, and the X-ray tube 24 and the FPD 25 supported by the C arm 23 also rotate around the axis of the body axis. . As described above, the motor 42 of the second video system drive unit 41 rotates the video system 2 having the X-ray tube 24 and the FPD 25 around the axis of the body axis by the rotation of the gear 45.

  In addition, a third video system driving unit 51 is provided that rotates the C arm 23 around an axis (y axis in the figure) orthogonal to the body axis (x axis in the figure) of the subject M in the horizontal plane. Yes. The C-arm 23 is formed in a rail shape, and the third video system drive unit 51 includes two bearings 52 fitted in the groove of the C-arm 23 and a belt 53 attached along the outer peripheral surface of the C-arm 23. And a motor 54 that winds up a part of the belt 53. When the motor 54 is driven to rotate, the belt 53 rotates and the C arm 23 slides relative to the bearing 52 accordingly. By this sliding, the C-arm 23 is rotationally moved around the axis of the axis orthogonal to the body axis in the horizontal plane. Further, the X-ray tube 24 and the FPD 25 supported by the C arm 23 also rotate around the axis of the axis orthogonal to the body axis in the horizontal plane. As described above, the motor 54 of the third video system driving unit 51 rotates the video system 2 having the X-ray tube 24 and the FPD 25 around the axis of the axis orthogonal to the body axis in the horizontal plane.

  In FIG. 1, the third video system driving unit 51 is not configured with a gear, but the top video driving unit, the top plate lifting unit, the first video system driving unit 31, and the second video system driving unit 41 are configured with a gear. It may be configured. The third video system driving unit 51 includes, for example, a motor, a gear (not shown) attached to the motor via a rotation shaft (not shown), and a tooth along the outer peripheral surface of the C arm 23 that is meshed with the gear. An arc-shaped rack (not shown) having In this case, when the motor is driven to rotate, the gear rotates about the axis of the axis orthogonal to the body axis in the horizontal plane via the rotating shaft. In conjunction with the rotation of the gear, the C arm 23 rotates together with the arc-shaped rack meshed with it and rotates around the axis of the axis perpendicular to the body axis in the horizontal plane, and is supported by the C arm 23. The tube 24 and the FPD 25 also rotate around the axis of the axis orthogonal to the body axis in the horizontal plane.

  In addition, by moving the base unit 21, the C arm support unit 22 or the C arm 23 in the horizontal direction (for example, the x direction or the y direction in the drawing), the video system 2 is driven in parallel in the horizontal direction. A system drive unit (not shown), an FPD moving unit (not shown) that the C arm 23 drives to rotate around a support axis supporting the FPD 25, and the like are provided. In addition, an image system elevating unit (not shown) that drives the image system 2 in parallel along the vertical axis by moving the C arm support unit 22 or the C arm 23 along the vertical axis may be provided.

  The video system driving unit and the video system lifting / lowering unit that are driven in parallel in the above-described directions may also be configured with gears. Similar to the top plate driving unit and the top plate lifting unit, the video system driving unit and the video system lifting unit include, for example, a motor and a gear (not shown) attached to the motor via a rotation shaft (not shown), A flat rack (not shown) that is engaged with the gear and supports the base 21, the C-arm support 22 and the C-arm 23 may be provided. In this case, the gear is rotated through the rotation shaft when the motor is driven to rotate. In conjunction with the rotation of the gear, the flat rack meshed with the gear changes the driving direction from the rotational direction to the straight traveling direction, and the base portion 21, the C-arm support portion 22, and the C-arm 23, together with the flat plate rack, respectively. The X-ray tube 24 and the FPD 25 supported by them are also translated in the respective directions.

  When the top plate 1 is driven in parallel in the horizontal direction as in the top plate drive unit, the video system 2 (X-ray tube 24 and FPD 25) is driven to rotate around the vertical axis as in the first video system drive unit 31. When the video system 2 rotates and moves in a horizontal plane, when the video system 2 (X-ray tube 24 and FPD 25) is driven in parallel in the horizontal direction as in the video system drive unit, it is not driven in the vertical direction. Therefore, when the top plate drive unit, the first video system drive unit 31 and the video system drive unit are configured with the above-described gears, the rotation error due to the backlash described above occurs as described in the top plate drive unit. Therefore, as described later, (A) actual positional deviation information or (B) the rotation angle of the motor during fluoroscopy or photographing may be obtained.

  On the other hand, when the top plate 1 is moved up and down like the top plate elevating unit, the horizontal axis (for example, the x axis and the y axis in the figure) like the second video system driving unit 41 and the third video system driving unit 51 is used. When the video system 2 is rotated around the axis, the vertical drive is also included when the video system 2 is moved up and down as in the video system lifting unit. Therefore, since these movements are also affected by gravity in the vertical direction, it is necessary to consider the rotation angle especially for positional deviation information at the time of stopping. Therefore, when these top plate elevating unit, second video system driving unit 41, third video system driving unit 51, and video system elevating unit are configured with the above-described gears, they rotate as described in the top plate elevating unit. Depending on the angle, the influence of gravity is more dominant than the backlash, so it is not always necessary to obtain (A) actual positional deviation information or (B) the rotation angle of the motor during fluoroscopy or photographing. Of course, it is also possible to combine both positional deviation information due to gravity and positional deviation information due to rotation error due to backlash.

  In addition, you may provide the FPD moving part (illustration omitted) which translates FPD25 along the support-axis direction in which C arm 23 supports FPD25. In this case, since the support shaft on which the C-arm 23 supports the FPD 25 is parallel to the perpendicular direction (ie, the irradiation center axis) lowered from the X-ray tube 24 to the FPD 25, the FPD moving portion is along the support shaft direction. By translating the FPD 25, the FPD 25 is translated along the perpendicular direction. That is, the FPD moving unit changes the distance (ie, SID: Source Image Distance) at which the perpendicular line is dropped from the X-ray tube 24 to the FPD 25, and the video system 2 is translated in the perpendicular direction.

  The X-ray detection signal obtained by moving the top board 1 and the video system 2 as described above and the FPD 25 detects the X-rays emitted from the X-ray tube 24 is processed by the image processing system 6 described later. Thus, an X-ray image of the subject M is obtained. In this way, the rotating means (motor) for driving at least one of the supporting means (the top plate 1 in each embodiment) supporting the imaging system 2 and the subject M by the rotation of the gear is provided. At least one of them is driven by rotation of a gear by a (motor), and the subject M is seen through or imaged by the video system 2. The fluoroscopy of the subject M is performed by sequentially displaying in real time an X-ray image obtained by irradiating a dose of X-ray that is weaker than that at the time of imaging. For imaging of the subject M, an X-ray image obtained by irradiating a normal dose of X-rays is temporarily stored in a storage medium (memory unit 68 in FIG. 2) represented by a RAM (Random-Access Memory) or the like. This is done by writing to and storing, and then reading and displaying or printing.

  Next, the image processing system 6 will be described with reference to FIG. The image processing system 6 includes a top plate drive control unit 61 that controls a motor (not shown) of the top plate drive unit and the top plate elevating unit in order to drive the top plate 1 in parallel, and a rotational drive or parallel drive of the video system 2. In order to achieve this, the motor 32 (see FIG. 1) of the first video system drive unit 31 (see FIG. 1), the motor 42 (see FIG. 1) of the second video system drive unit 41 (see FIG. 1) and the second A video system drive control unit 62 that controls the motor 54 (see FIG. 1) of the 3 video system drive unit 51 (see FIG. 1), and a tube voltage and a tube current are applied to the X-ray tube 24 to provide the X-ray tube 24. An X-ray tube control unit 63 that controls the image, an image processing unit 64 that processes the X-ray detection signal detected by the FPD 25 as an X-ray image, and (A) actual positional deviation information, or (B) at the time of fluoroscopy or imaging Calculation unit 65 for calculating the rotation angle of the motor and gear backlash The table 66 pre-stores the correlation in which the positional deviation information and the rotation direction of the gear immediately before the positional deviation information are associated with each other, the controller 67 that performs overall control thereof, and the image processing unit 64 A memory unit 68 that stores the X-ray image and the like, an input unit 69 that performs input setting, and an output unit 70 that outputs an image processed by the image processing unit 64. The arithmetic unit 65 corresponds to the arithmetic means in the present invention, and the table 66 corresponds to the storage means in the present invention.

  The top plate drive control unit 61 controls each motor (not shown) to rotate as described above, thereby driving the top plate 1 in parallel in the directions of the arrows in FIG. 1 by rotation of gears (not shown). The video system drive control unit 62 controls the rotation of each motor as described above, so that the movable part of the video system 2 (the base unit 21, the C arm support unit 22, the C arm 23, the X-ray tube 24, and the FPD 25). Is driven in the direction of the arrow in FIG. 1 by the rotation of each gear. The top panel drive control unit 61, the video system drive control unit 62, the X-ray tube control unit 63, the image processing unit 64, the calculation unit 65, and the controller 67 are configured by a central processing unit (CPU) and the like.

  The X-ray tube control unit 63 controls the X-ray tube 24 by applying a tube voltage or a tube current to the X-ray tube 24. The X-ray tube control unit 63 controls a collimator (not shown) to control the irradiation field of X-rays emitted from the X-ray tube 24. The image processing unit 64 performs various types of image processing (for example, lag correction and gain correction) on the X-rays (X-ray detection signals) irradiated from the X-ray tube 24 and transmitted through the subject M and detected by the FPD 25. To obtain an X-ray image of the subject M. The X-ray image is sent to the memory unit 68 and the output unit 70 via the controller 67 as necessary.

  Further, since a rotation error occurs due to the gear backlash, the calculation unit 65 obtains the actual positional deviation information and the rotation angle of the motor at the time of fluoroscopy or photographing, and sends them to the controller 67 or via the controller 67. To the image processing unit 64. In particular, when the image processing unit 64 obtains a three-dimensional image such as a tomographic image, the actual position of the video system 2 and the actual rotation angle at the time of photographing are required. After being sent to the unit 64, the image processing unit 64 obtains a three-dimensional image based on these.

  Specific functions of the calculation unit 65 and the table 66 will be described later with reference to FIG. The memory unit 68 is configured by a storage medium such as a ROM (Read-only Memory) or a RAM (Random-Access Memory), and writes and stores the X-ray image processed by the image processing unit 64. The X-ray image is read out as necessary. The table 66 is composed of a storage medium represented by a RAM or the like, and stores and stores the above-described correlation in advance prior to fluoroscopy or radiography, and reads and refers to it during fluoroscopy or radiography. Further, it is possible to overwrite and store the data in order to update the correlation, or to write and store the data additionally.

  The input unit 69 includes a pointing device represented by a mouse, a keyboard, a joystick, a trackball, a touch panel, and the like. An operator (operator) inputs a command (command) related to imaging via the input unit 69, and the top panel drive control unit 61, the video system drive control unit 62, the X-ray tube control unit 63, and the like via the controller 67. To send. The output unit 69 is a display unit represented by a monitor or a printing unit represented by a printer.

  In FIG. 2, the CPU is separated into a top panel drive control unit 61, a video system drive control unit 62, an X-ray tube control unit 63, an image processing unit 64, a calculation unit 65, and a controller 67, respectively. However, it may be combined into one or more. In particular, the function of the calculation unit 65 corresponding to the calculation means in the present invention may be shared by the image processing unit 64 or the controller 67, or the functions of the image processing unit 64 and the calculation unit 65 may be shared by the controller 67. Good.

  Next, specific functions of the calculation unit 65 and the table 66 will be described with reference to FIG. FIG. 3 is a schematic diagram for explanation of performing a first calculation for obtaining positional deviation information during rotation with reference to the table according to the first embodiment.

Prior to fluoroscopy or photographing, the positional deviation information due to gear backlash and the rotation direction of the gear immediately before the occurrence of the positional deviation information are associated with each other as shown in FIG. (See) in advance. For example, as shown in FIG. 3, gear when rotated to the right direction in FIG. And R _1, which when rotated to the left direction in FIG. And L _1.

Since the positional deviation changes in accordance with these rotational directions, the positional deviation information at R ₁ when the gear rotates in the right direction R ₁ and the position at L ₁ when the gear rotates in the left direction L _1. Find the gap information. When obtaining the positional deviation information, it is preferable to detect the positional deviation information by a highly accurate position detecting means or the like.

As positional deviation information, when the driving direction of the video system 2 (see FIGS. 1 and 2) is the rotation direction by the first video system driving unit 31 and the second video system driving unit 41 (both refer to FIG. 1). 1 may be detected by a rotational angle deviation Δθ _X (the unit is “radian” or “°”) as shown in FIG. 1 or converted into an orthogonal coordinate system (x, y, z in FIG. 1). You may detect with the gap which did. Further, when the driving direction of the video system 2 is the straight direction, the positional deviation information is preferably a deviation amount in an orthogonal coordinate system (x, y, z in FIG. 1). Only the difference Δ in which the deviation has occurred may be detected as the positional deviation information, or the amount of movement from the reference position represented by the start position at the time of fluoroscopy or photographing to the current position (that is, the difference Δ in which the deviation has occurred). The total amount of movement considered) may be detected as positional deviation information.

In the same manner, the rotation of the gears in the right direction R ₂ , R ₃ ,. Are obtained in accordance with the rotation directions L ₂ , L ₃ ,.

Further, when the motor is rotating, the positional deviation information becomes positional deviation information during the rotation of the motor. This will be described with reference to FIGS. 8 (a) to 8 (c). 8A to 8C, it is assumed that the gear g is rotated in the left direction (counterclockwise) and stopped. It should be noted that the state before the start of rotation is indefinite because it depends on the rotation direction immediately before the stop. When the motor starts to rotate, since the deviation [Delta] [theta] _X occurs after Δt elapses from the start of rotation is a constant deviation [Delta] [theta] _X is in a rotated together with the gear g a state shown in FIG. 8 (c) rack r is started to rotate Become. When the motor stops rotating, only the rack r rotates slightly after the lapse of Δt ′ from the rotation stop, and after reaching the state shown in FIG. 8B, the rack r also stops. As described above, a time lag is generated by Δt from the start of rotation and Δt ′ from the stop of rotation. However, Δt and Δt ′ are minute time intervals and can be ignored.

In addition, when obtaining the positional deviation information during rotation, since the motor is rotating, it is difficult for the position detection means to detect the positional deviation information. In that case, positional deviation information at the time of stopping is acquired in advance, and positional deviation information when the rotation direction immediately before the stop is leftward is Δθ _L (BL), and when it is rightward, Δθ _R (BL). The position deviation information during rotation in the left direction is Δθ _R (BL), and the position deviation information during rotation in the right direction is Δθ _L (BL). May be.

As shown in FIG. 3, the calculation unit 65 (see FIG. 2) refers to the table 66 associated with each other, and performs a first calculation for obtaining actual positional deviation information during rotation of the motor. For example, when the actual gear rotation direction at the time of fluoroscopy or photographing rotates in the right direction _Rb , it is obtained as shown in FIG. The rotation angle deviation Δθ _Rb at the time of R _b shown by a thick frame is obtained as actual positional deviation information during rotation of the motor.

Further, when the actual gear rotation direction at the time of fluoroscopy or photographing rotates in the left direction _Lb , it is obtained as shown in FIG. The deviation [Delta] [theta] _Lb of the rotational angle when the L _b depicted by a bold frame is obtained as the actual positional displacement information in the rotation of the motor.

  Only the first calculation for obtaining positional deviation information may be performed, or the following second calculation may be performed together with the first calculation described above. When the driving direction of the video system 2 is the rotational direction and the positional deviation information is a rotational angle deviation as shown in FIG. 3, only the first calculation is required, but the driving direction of the video system 2 is the rotational direction. Thus, when the displacement detected in the orthogonal coordinate system is detected, the rotation angle may be converted again, and the rotation angle of the motor at the time of fluoroscopy or photographing corresponding to the rotation angle of the video system 2 may be obtained. A table may be created in advance for the correlation between the rotation angle of the video system 2 and the rotation angle of the motor, and the rotation angle of the motor may be obtained by referring to the table.

  Further, when the driving direction of the video system 2 is a straight traveling direction and the positional shift information is a shift amount in the orthogonal coordinate system, the rotation is performed again by converting the same arc as the shift amount into a rotation angle. You may obtain | require the rotation angle of the motor at the time of fluoroscopic imaging | photography or imaging | photography corresponding to an angle. Similarly, a table may be created in advance for the correlation between the rotation angle of the video system 2 and the rotation angle of the motor, and the rotation angle of the motor may be obtained by referring to the table.

  According to the X-ray apparatus according to the first embodiment, the table 66 stores in advance the correlation that associates the positional deviation information due to the backlash of the gear with the rotation direction of the gear immediately before the positional deviation information is generated. To do. As described above, in order to create this correlation, it is preferable to detect positional deviation information by a highly accurate position detecting means or the like. Since this positional deviation information is associated with the rotation direction of the gear immediately before the positional deviation information has occurred, it can be obtained in advance as a correlation in which these are associated with each other.

  Using this correlation, the calculation unit 65 performs the following first calculation or second calculation together with the first calculation. In the case of (A), based on the actual gear rotation direction at the time of fluoroscopy or photographing and the above-described correlation, the position shift information corresponding to the rotation direction of the actual gear is the actual position shift information. It is obtained by performing one operation. On the other hand, in the case of (B), the rotation angle of the rotating means (motor) during fluoroscopy or photographing is obtained by performing the second calculation based on the actual positional deviation information obtained by the first calculation. It is done. As a result, based on the above-described correlation, actual positional deviation information can be obtained, or the rotation angle of the rotating means (motor) during fluoroscopy or photographing can be obtained accurately.

In the X-ray apparatus, when the rotating means (motor) is rotating as in the first embodiment, the following configuration is preferable.
That is, in the above-described correlation, the positional deviation information during rotation of the rotating means (motor) and the rotation direction of the gear are associated with each other and stored in advance in the above-described table 66. Alternatively, a first calculation for obtaining actual positional deviation information during rotation of the rotating means (motor) is performed based on the actual rotation direction of the gear at the time of photographing and the above-described correlation, or (B) obtained by the first calculation. It is preferable to perform the second calculation for obtaining the rotation angle of the rotating means (motor) at the time of fluoroscopic observation or photographing during the rotation based on the actual positional deviation information during the rotation together with the first calculation described above.

  When the rotating means (motor) is rotating, the positional deviation information during rotation of the rotating means (motor) is obtained, and the correlation in which the positional deviation information during rotation is associated with the rotation direction of the gear. Can be stored in the table 66 in advance. In the case of (A), based on the actual gear rotation direction at the time of fluoroscopy or photographing and the above-mentioned correlation, the positional deviation information corresponding to the actual gear rotation direction indicates that the rotation means (motor) is rotating. It is obtained by performing the first calculation as actual positional deviation information. On the other hand, in the case of (B), the rotation angle of the rotating means (motor) at the time of fluoroscopy or photographing during rotation is based on the actual positional deviation information during rotation obtained by the first calculation described above. It is obtained by performing an operation.

Next, Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic diagram for explaining the first calculation for obtaining positional deviation information with reference to the table according to the second embodiment. The parts common to the above-described first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Further, the configuration of FIG. 1 and the image processing system 2 of FIG.

  Similar to the first embodiment described above, the image processing system 6 according to the second embodiment includes a top panel drive control unit 61, a video system drive control unit 62, an X-ray tube control unit 63, and an image process as shown in FIG. A unit 64, a calculation unit 65, a table 66, a controller 67, a memory unit 68, an input unit 69, and an output unit 70 are provided. The arithmetic unit 65 corresponds to the arithmetic means in the present invention, and the table 66 corresponds to the storage means in the present invention.

The difference from the first embodiment is that, in the first embodiment, the positional deviation information is the positional deviation information during the rotation of the motor (the deviation Δθ _{X in} FIG. 3), whereas in the second embodiment, the positional deviation information is different. This is positional deviation information when the motor is stopped (in FIG. 4, deviation Δθ _X (BL)). In the second embodiment, the rotational direction is the rotational direction immediately before the gear is stopped. Therefore, in the second embodiment, as shown in FIG. 4, the positional deviation information when the motor is stopped and the rotation direction immediately before the gear stop are associated with each other and written in advance in the table 66 (see FIG. 2). Remember me.

As in FIG. 3, the positional shift changes according to the rotation direction. Therefore, as illustrated in FIG. 4, the positional shift information at R ₁ immediately before the stop when the gear rotates and stops in the right direction R ₁ , and gear respectively obtained and positional displacement information in the L ₁ immediately before stopping when rotated and stopped to the left L _1.

As shown in FIG. 4, the calculation unit 65 (see FIG. 2) refers to the table 66 associated with each other, and performs a first calculation for obtaining actual positional deviation information when the motor is stopped. For example, when the actual gear rotation direction at the time of fluoroscopy or photographing is rotated in the right direction _Rb , it is obtained as shown in FIG. A rotation angle shift Δθ _Rb (BL) at R _b shown in a thick frame is obtained as actual position shift information when the motor is stopped.

Further, when the actual gear rotation direction at the time of fluoroscopy or photographing is rotated in the left direction _Lb , it is obtained as shown in FIG. The deviation [Delta] [theta] _{Lb (BL)} of the rotational angle when the L _b depicted by a bold frame is obtained as the actual positional deviation information at the time of stopping the motor.

  As in the first embodiment, when the driving direction of the video system 2 is the rotation direction and the positional deviation information is a deviation of the rotational angle as shown in FIG. In the case where the driving direction of 2 is a rotation direction, if it is detected by a shift converted to an orthogonal coordinate system, it is converted again to a rotation angle, and a motor at the time of fluoroscopy at the time of stopping or photographing corresponding to the rotation angle of the video system 2 The rotation angle may be obtained. Further, when the driving direction of the video system 2 is a straight traveling direction and the positional shift information is a shift amount in the orthogonal coordinate system, the rotation is performed again by converting the same arc as the shift amount into a rotation angle. You may obtain | require the rotation angle of the motor at the time of fluoroscopy at the time of a stop corresponding to an angle, or imaging | photography.

  According to the X-ray apparatus according to the second embodiment, as in the first embodiment described above, the positional deviation information due to the gear backlash is associated with the rotation direction of the gear immediately before the positional deviation information is generated. The correlation is stored in the table 66 in advance. In the case of (A), based on the rotation direction and correlation of the actual gear at the time of fluoroscopy or photographing, the position shift information corresponding to the rotation direction of the actual gear is the first calculation as the actual position shift information. It is required by doing. On the other hand, in the case of (B), the rotation angle of the rotating means (motor) during fluoroscopy or photographing is obtained by performing the second calculation based on the actual positional deviation information obtained by the first calculation. It is done. As a result, based on the above-described correlation, actual positional deviation information can be obtained, or the rotation angle (motor) of the rotating means at the time of fluoroscopy or photographing can be obtained accurately.

In the X-ray apparatus, when the rotating means (motor) is stopped as in the second embodiment, the following configuration is preferable.
That is, in the above correlation, the positional deviation information at the time when the rotating means (motor) is stopped and the rotation direction immediately before the gear is stopped are associated with each other in advance and stored in the table 66. (A) Performing a first calculation for obtaining actual positional deviation information when the rotating means (motor) is stopped based on the rotational direction of the actual gear at the time of fluoroscopy or photographing and the above-mentioned correlation, or (B) The second calculation for obtaining the rotation angle of the rotating means (motor) at the time of fluoroscopy at the time of stop or photographing based on the actual positional deviation information at the time of stop obtained by the first calculation together with the above first calculation It is preferred to do so.

  When the rotation means (motor) is stopped, position deviation information when the rotation means (motor) is stopped is obtained, and the position deviation information when the rotation means (motor) is stopped and the rotation direction immediately before stopping the gear are respectively obtained. It can be stored in advance in the table 66 as the correlated correlation. In the case of (A), positional deviation information corresponding to the rotation direction immediately before the actual gear stop is based on the rotation direction immediately before the actual gear stop and the above-described correlation during fluoroscopy or photographing. It is calculated | required by performing a 1st calculation as position shift information at the time of a stop of a motor. On the other hand, in the case of (B), the rotation angle of the rotating means (motor) at the time of fluoroscopy at the time of stop or photographing is based on the actual positional deviation information at the time of stop obtained by the first calculation described above. It is obtained by performing the second calculation.

Next, Embodiment 3 of the present invention will be described with reference to the drawings.
FIG. 5 is a block diagram of an image processing system in the X-ray apparatus according to the third embodiment. The parts common to the first and second embodiments described above are denoted by the same reference numerals, and the description thereof is omitted. The configuration of FIG. 1 other than the image processing system 2 is common to the first and second embodiments.

  As in the first and second embodiments, the image processing system 6 according to the third embodiment includes a top panel drive control unit 61, a video system drive control unit 62, and an X-ray tube control unit 63 as shown in FIG. An image processing unit 64, a calculation unit 65, a table 66, a controller 67, a memory unit 68, an input unit 69, and an output unit 70 are provided. The top panel drive control unit 61 and the video system drive control unit 62 correspond to control means in the present invention, the calculation unit 65 corresponds to calculation means in the present invention, and the table 66 corresponds to storage means in the present invention. .

  The difference from the first and second embodiments is that, in the third embodiment, the rotation direction of the gear is determined based on the first calculation and the second calculation in the calculation unit 65, and the rotation means (motor) The motor 12 (see FIG. 1), the motor 32 (see FIG. 1) of the first video system drive unit 31 (see FIG. 1), and the second video system drive unit 41 (see FIG. 1) so as to control the rotation to the target rotation angle. The top plate drive control unit 61 and the video system drive control unit 62 have the function of the control means for controlling the motor 42 (see FIG. 1) of the motor 42 (see FIG. 1). Therefore, in the third embodiment, as shown in FIG. 5, positional deviation information and the like in the calculation unit 65 are sent to the top board drive control unit 61 and the video system drive control unit 62.

For example, as in the table shown in FIG. 4 of the second embodiment, when the actual gear rotation direction at the time of fluoroscopy or photographing is associated with the rotation angle deviation Δθ _X (BL), the target rotation When the angle is θ, the target rotation angle θ includes a rotation angle shift Δθ _X (BL). Therefore, if rotational driving is performed at an angle of (θ−Δθ _X (BL)), the rotational angle deviation Δθ _X (BL) is added. As a result, the deviation Δθ _X (BL) is canceled and the motor rotates to the target rotational angle θ. Can be controlled. Here, the rotation control is performed so as to reach the shortest distance (minimum angle), but it is also possible to perform the rotation control as follows.

  That is, when controlling the rotation to the target rotation angle, if the rotation control is performed at the same target rotation angle, there is a backlash between the rotation from the left direction and the rotation from the right direction. The rotation is controlled so as to reach (for example, from the right direction). That is, for example, in the case of rotation from the left direction, the rotation is controlled so as to reach the target rotation angle by rotation from the right direction so as to pass the target rotation angle and then return to the target rotation angle. Moreover, you may combine the rotation control which reaches | attains with the above-mentioned shortest distance (minimum angle), and the rotation control which returns to the target rotation angle once it passes the target rotation angle.

  The positional deviation information in the table shown in FIG. 4 is a case where only the difference Δ in which the deviation has occurred is detected, but as described in the first embodiment, the reference represented by the start position at the time of fluoroscopy or photographing, etc. When the amount of movement from the position to the current position (that is, the total amount of movement considering the difference Δ in which the deviation has occurred) is detected as position deviation information, the following control is performed. In other words, since the actual gear rotation direction during fluoroscopy or shooting is associated with the amount of movement to the current position, if the rotation is driven to the amount of movement to the current position, the rotation angle at the current position is the target. It becomes a rotation angle and the motor can be controlled. Therefore, the positional deviation information in the table can be controlled as the target rotation angle without subtracting the deviation amount.

  According to the X-ray apparatus according to the third embodiment, as in the first and second embodiments described above, the positional deviation information due to the backlash of the gear and the rotation direction of the gear immediately before the positional deviation information is generated are respectively shown. The associated correlation is stored in the table 66 in advance. In the case of (A), based on the rotation direction and correlation of the actual gear at the time of fluoroscopy or photographing, the position shift information corresponding to the rotation direction of the actual gear is the first calculation as the actual position shift information. It is required by doing. On the other hand, in the case of (B), the rotation angle of the rotating means (motor) during fluoroscopy or photographing is obtained by performing the second calculation based on the actual positional deviation information obtained by the first calculation. It is done. As a result, based on the above-described correlation, actual positional deviation information can be obtained, or the rotation angle (motor) of the rotating means at the time of fluoroscopy or photographing can be obtained accurately.

  In the X-ray apparatus according to the third embodiment, the rotation direction of the gear rotation is determined based on the first calculation and the second calculation in the calculation unit 65, and the target rotation angle of the rotation means (motor) is determined. It is even more preferable to provide control means (the top panel drive control unit 61 and the video system drive control unit 62 in the third embodiment) for controlling the rotation means (motor) so as to control the rotation. Since the positional deviation information when the rotation means (motor) is rotated to the target rotation angle and stopped is stored in advance in the above-described correlation, in order to control the target rotation angle based on the first calculation and the second calculation. The target rotation angle of the gear can be determined, and as a result, the control means (top plate drive control unit 61 and video system drive control unit 62) can control the rotation to the target rotation angle. Therefore, it is possible to control the rotating means (motor) so as to control the rotation to the target rotation angle without causing a positional shift.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In each of the above-described embodiments, the X-ray apparatus provided with the C-arm as shown in FIG. 1 has been described as an example. However, the video system and supporting means for supporting the subject (the top plate in each embodiment) The X-ray apparatus is not particularly limited as long as at least one of 1) is driven by the rotation of a gear to perform fluoroscopy or imaging of the subject by an image system. The present invention can also be applied to an X-ray apparatus in which only the video system is driven by the rotation of the gear and only the support means is driven by the rotation of the gear. In addition, as described in the first embodiment, the X-ray apparatus is configured to convert the driving direction from the rotation direction to the straight traveling direction in conjunction with the rotation of the gear and drive at least one of the video system and the support unit in parallel. You may apply.

  (2) In each of the above-described embodiments, the top plate on which the subject is placed is described as an example of the support means. However, if the support means supports the subject, a round bed or a standing posture is used. The support means is not particularly limited as exemplified by an upright stand that performs only fluoroscopy or photographing.

  (3) As shown in FIG. 6, the top plate 1 may be applied to a device that tilts up and down in a standing posture, an inclined posture, and a horizontal posture (a standing posture). Around the top plate 1, a main column 11 that supports the top plate 1, a motor 12 provided on the back of the main column 11, a rotary shaft 13 having one end attached to the motor 12, and the other end of the rotary shaft 13 And a fan-shaped rack 15 meshed with the gear 14. The rotating shaft 13 is inserted into the main column 11. The motor 12 corresponds to the rotating means in the present invention, and the gear 14 corresponds to the gear in the present invention.

  (4) In each of the embodiments described above, a flat panel X-ray detector (FPD) has been described as an example of the X-ray detector, but it is exemplified by an image intensifier (I.I) or the like. In addition, there is no particular limitation as long as it is an X-ray detector that detects X-rays that are normally used.

  (5) In the third embodiment described above, the positional deviation information in the calculation unit 65 is sent to the top panel drive control unit 61 and the video system drive control unit 62 as shown in FIG. 61 and the video system drive control unit 62 are sent directly, but when the controller 67 also functions as the top panel drive control unit 61 and the video system drive control unit 62, as shown in FIG. The controller 67 may directly control. In the case of FIG. 7, the controller 67 corresponds to the control means in this invention.

DESCRIPTION OF SYMBOLS 1 ... Top plate 2 ... Video system 12, 32, 42, 54 ... Motor 14, 35, 45 ... Gear 61 ... Top plate drive control part 62 ... Video system drive control part 65 ... Calculation part 66 ... Table 67 ... Controller M ... Subject

Claims (4)

Rotating means for driving at least one of the imaging system and the supporting means for supporting the subject by rotation of the gear,
An X-ray apparatus that performs fluoroscopy or imaging of the subject by the video system by driving at least one of the gears by rotation of the rotating means,
Storage means for preliminarily storing a correlation in which the positional deviation information due to the backlash of the gear and the rotation direction of the gear immediately before the positional deviation information are associated with each other;
(A) A first calculation for obtaining actual positional deviation information based on the actual gear rotation direction and the correlation during fluoroscopy or photographing is performed, or (B) the actual position obtained by the first calculation. An X-ray apparatus comprising: a calculation unit that performs a second calculation for obtaining a rotation angle of the rotation unit at the time of fluoroscopy or imaging based on deviation information together with the first calculation. The X-ray apparatus according to claim 1,
In the correlation, the positional deviation information during rotation of the rotation means and the rotation direction of the gear are associated with each other and stored in advance in the storage means,
The calculation means (A) performs the first calculation to obtain actual positional deviation information during rotation of the rotation means based on the actual gear rotation direction and the correlation during fluoroscopy or photographing, or (B ) A second calculation for determining the rotation angle of the rotating means during fluoroscopy or photographing during rotation based on the actual positional deviation information during rotation determined by the first calculation is performed together with the first calculation. X-ray equipment. The X-ray apparatus according to claim 1,
In the correlation, the positional deviation information when the rotating means is stopped and the rotation direction immediately before the gear is stopped are associated with each other and stored in advance in the storage means,
The calculating means performs (A) a first calculation for obtaining actual positional deviation information when the rotating means is stopped based on the actual gear rotation direction and the correlation during fluoroscopy or photographing, or (B ) Performing a second calculation together with the first calculation for obtaining a rotation angle of the rotating means at the time of fluoroscopy at the time of stop or photographing based on the actual positional deviation information at the time of stop determined by the first calculation X-ray apparatus characterized by this. In the X-ray apparatus in any one of Claims 1-3,
Control means for determining the rotation direction of the rotation of the gear based on the first calculation and the second calculation by the calculation means and controlling the rotation means to control the rotation to the target rotation angle of the rotation means. An X-ray apparatus comprising:

Images