JP2015085070A - Fluoroscopic x-ray apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluoroscopic X-ray apparatus which, when performing an action of varying an inclination angle of a bed, can reduce a load applied on a motor for turning a bed.SOLUTION: A weight driving motor control part 52 detects a start of a turning action of an inclination angle variable part 18 on the basis of information from an inclination encoder 38 and calculates an inclination angle variable part 18's turning direction and inclination angle. After that, when performing an action of varying an inclination angle of a bed and wherever the position of the imaging device body 9 is, the weight driving motor control part 52 moves a balance weight 11 to the direction as approaching the downward moving one of both end parts of the bed in the longitudinal direction, so as to reduce a load of the inclination angle variable motor 32.

Description

  The present invention relates to an X-ray fluoroscopic apparatus, and particularly to control of a bed.

  In a conventional X-ray fluoroscopic apparatus, a balance weight is connected via a wire rope to a rapid-shooting device unit having an X-ray tube device and a rapid-shooting device, and when the rapid-motion device unit is moved in the longitudinal direction of the bed, The balance weight is moved in the direction opposite to the rapid photographing device (see, for example, Patent Document 1).

JP-A 61-288839

  As described above, with the configuration in which the balance weight is moved in the direction opposite to the speed-graphing device unit with respect to the movement of the speed-graphing device unit in the longitudinal direction of the bed, the moment around the rotation axis of the tilting operation of the bed is balanced. be able to. However, depending on the position of the balance weight, when the tilt angle of the bed is changed, the moment of the balance weight may act in a direction that gives resistance to the operation. This reduces the load on the motor for the tilt angle of the bed. It becomes an obstacle.

  The present invention has been made to solve the above-described problems, and provides an X-ray fluoroscopic apparatus capable of reducing a load applied to a motor that rotates a bed during a tilt angle changing operation of the bed. With the goal.

  The X-ray fluoroscopic apparatus according to the present invention includes a bed, an X-ray tube device, and an X-ray detector that can change an inclination angle by rotating around a rotation axis, and the longitudinal direction of the bed A balance weight movable in the longitudinal direction of the bed independently of the imaging apparatus body, and a balance weight in the longitudinal direction of the bed according to the position of the imaging apparatus body in the longitudinal direction of the bed. A weight position control unit is provided, and the weight position control unit moves the balance weight in a direction approaching an end portion that moves downward among both end portions in the longitudinal direction of the bed when the tilt angle of the bed is changed.

  In the X-ray fluoroscopic apparatus of the present invention, the weight position control unit moves the balance weight in a direction approaching an end portion that moves downward among both ends in the longitudinal direction of the bed at the time of the tilt angle changing operation of the bed. It is possible to reduce the load applied to the motor that rotates the bed during the tilt angle changing operation of the bed.

1 is a perspective view showing an X-ray fluoroscopic apparatus according to Embodiment 1 of the present invention. It is a side view which shows the principal part of the X-ray fluoroscopic apparatus of FIG. It is a side view which shows the movement mechanism of the balance weight of FIG. It is a side view which shows the drive mechanism of the imaging device main body and inclination angle variable part of FIG. It is a block diagram which shows the principal part of the X-ray fluoroscopic apparatus of FIG. It is a side view which shows the state which moved the imaging device main body of FIG. 2 to the head direction of the subject. FIG. 3 is a side view showing a state in which the imaging apparatus main body of FIG. 2 is moved in the direction of a subject's foot. It is a side view which shows the state in the middle of rotating the bed of FIG. 2 to the standing direction. It is a side view which shows the state which stopped rotation of the bed of FIG. It is a side view which shows the state in the middle of rotating the bed of FIG. 2 to a reverse inclination direction. It is a side view which shows the state which stopped rotation of the bed of FIG. It is a flowchart which shows operation | movement of the weight drive motor control part with respect to inclination angle variable switch operation of FIG. 6 is a flowchart illustrating an operation of a weight drive motor control unit in response to an operation of a photographing apparatus body movement switch in FIG. 5. It is explanatory drawing which shows the effect | action of the weight of the inclination angle variable part of the X-ray fluoroscopic imaging apparatus by Embodiment 3 of this invention, and the weight of a balance weight. FIG. 10 is a side view showing a main part of an X-ray fluoroscopic apparatus according to Embodiment 3. It is sectional drawing which follows the XVI-XVI line | wire of FIG. 10 is an explanatory diagram illustrating a method of calculating a balance weight movement amount according to Embodiment 3. FIG. FIG. 10 is a block diagram illustrating a main part of an X-ray fluoroscopic apparatus according to a third embodiment. 12 is a flowchart showing an outline of the operation of the weight drive motor control unit when the bed of the third embodiment is stationary.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
1 is a perspective view showing an X-ray fluoroscopic apparatus according to Embodiment 1 of the present invention. In the figure, a support frame 2 is supported on the leg 1. A bed 3 on which a subject is placed is supported on the support frame 2. The support frame 2 and the bed 3 can be rotated (tilted up and down) with respect to the leg 1 about a rotation axis 4 (FIG. 2) that is perpendicular to the longitudinal direction of the bed 3 and is horizontal. Thereby, the inclination angle of the bed 3 can be changed.

  A pair of support columns 5 are supported on the support frame 2. The support columns 5 are arranged at intervals in the longitudinal direction of the bed 3. An X-ray tube device 6 that irradiates the subject with X-rays and an X-ray diaphragm device 7 that sets an X-ray irradiation region for the subject are supported at the upper end of the column 5. An X-ray detector 8 that detects X-rays transmitted through the subject is supported at the lower end of the column 5.

  The X-ray tube device 6 and the X-ray diaphragm device 7 are disposed above the bed 3 when the bed 3 is in a horizontal state. The X-ray detector 8 is disposed below the bed 3 when the bed 3 is in a horizontal state. The X-ray detector 8 faces the X-ray tube device 6 with the bed 3 interposed therebetween. The X-ray diaphragm device 7 is disposed on the bed 3 side of the X-ray tube device 6.

  The imaging apparatus main body (video system) 9 includes a support column 5, an X-ray tube device 6, an X-ray diaphragm device 7, and an X-ray detector 8. Further, the photographing apparatus main body 9 can be moved in the longitudinal direction of the bed 3 by a support column moving mechanism unit 10. Further, the X-ray tube device 6, the X-ray diaphragm device 7, and the X-ray detector 8 move in the short direction of the bed 3 (direction perpendicular to the longitudinal direction and parallel to the upper surface of the bed 3) with respect to the column 5. It is possible.

  A balance weight 11 is supported on the support frame 2. The balance weight 11 can be moved in the longitudinal direction of the bed 3 independently from the photographing apparatus main body 9. The weight of the balance weight 11 is set according to the weight of the photographing apparatus main body 9, and is about 100 kg, for example.

  The high voltage generator 12 supplies power to the X-ray tube device 6. The X-ray image processing unit 13 performs image processing using the X-ray signal detected by the X-ray detector 8. The display device 14 displays the X-ray image obtained by the X-ray image processing unit 13. The external storage unit 15 stores and stores the X-ray image data obtained by the X-ray image processing unit 13. The control unit 16 controls the entire X-ray fluoroscopic apparatus. Input of a command to the control unit 16 is performed by the operation unit 17.

  FIG. 2 is a side view showing a main part of the X-ray fluoroscopic apparatus of FIG. The X-ray fluoroscopic apparatus according to the first embodiment rotates about an imaging apparatus main body 9 that moves in the longitudinal direction of the bed 3, a balance weight 11 that also moves in the longitudinal direction of the bed 3, and a rotation shaft 4. Thus, there are included three movable parts of an inclination angle variable part (raising / lowering part) 18 capable of changing the inclination angle. The tilt angle variable unit 18 includes a support frame 2, a bed 3, an imaging device main body 9, and a balance weight 11.

  FIG. 3 is a side view showing a moving mechanism of the balance weight 11 of FIG. A base 21 is fixed to the support frame 2. A linear motion guide 22 that guides the movement of the balance weight 11 is fixed to the base 21. The balance weight 11 slides along the linear motion guide 22.

  The support frame 2 is provided with a drive sprocket 23 and a driven sprocket 24. A chain 25 is wound around the drive sprocket 23 and the driven sprocket 24. The chain 25 is connected to the balance weight 11. A weight drive motor 26 that rotates the drive sprocket 23 is connected to the drive sprocket 23. The balance weight 11 moves in parallel with the upper surface of the bed 3 in the longitudinal direction of the bed 3 by rotating the drive sprocket 23 by the weight drive motor 26.

  The rotation of the drive sprocket 23 is transmitted to the encoder sprocket 27. A weight encoder 28 is connected to the encoder sprocket 27. A signal from the weight encoder 28 is output to the control unit 16. The control unit 16 obtains the relative position information of the balance weight 11 based on the signal from the weight encoder 28.

  The base 21 is provided with a first limit switch 29 that detects that the balance weight 11 is located at one end of the movable range, and a second limit switch 30 that detects that the balance weight 11 is located at the other end. ing. An operation cam 31 that mechanically operates the first and second limit switches 29 and 30 is fixed to the balance weight 11.

  Signals from the first and second limit switches 29 and 30 are output to the control unit 16. The control unit 16 detects the absolute position of the balance weight 11 based on signals from the first and second limit switches 29 and 30. Further, when the first or second limit switch 29, 30 is operated, the control unit 16 prevents the weight drive motor 26 from being driven in a direction in which the balance weight 11 goes out of its movable range.

  FIG. 4 is a side view showing a driving mechanism of the photographing apparatus main body 9 and the tilt angle variable unit 18 of FIG. The tilt angle variable unit 18 is rotated about the rotation shaft 4 by the tilt angle variable motor 32. A tilted sprocket 33 is connected to the tilt angle variable motor 32. The tilt angle variable portion 18 is provided with a gear 34 that rotates integrally with the tilt angle variable portion 18 around the rotation shaft 4.

  A chain 35 is wound between the inclined sprocket 33 and the gear 34. The driving force of the variable tilt angle motor 32 is transmitted to the variable tilt angle unit 18 via the tilt sprocket 33, the chain 35, and the gear 34.

  The rotation of the inclined sprocket 33 is transmitted to the encoder sprocket 37 via the chain 36. A tilt encoder 38 is connected to the encoder sprocket 37. A signal from the tilt encoder 38 is output to the control unit 16. The control unit 16 detects the tilt angle of the bed 3 based on the signal from the tilt encoder 38.

  The support frame 2 is provided with a drive sprocket 39 and a driven sprocket 40. A chain 41 is wound around the drive sprocket 39 and the driven sprocket 40. The chain 41 is connected to the photographing apparatus main body 9. The driving sprocket 39 is connected to an imaging apparatus main body driving motor 42 that rotates the driving sprocket 39. The imaging apparatus main body 9 moves in parallel with the upper surface of the bed 3 in the longitudinal direction of the bed 3 by rotating the drive sprocket 39 by the imaging apparatus body drive motor 42.

  The rotation of the drive sprocket 39 is transmitted to the encoder sprocket 44 through the chain 43. An imaging device main body encoder 45 is connected to the encoder sprocket 44. A signal from the imaging apparatus main body encoder 45 is output to the control unit 16. The control unit 16 obtains relative position information of the photographing apparatus main body 9 based on a signal from the photographing apparatus main body encoder 45.

  FIG. 5 is a block diagram showing a main part of the X-ray fluoroscopic apparatus of FIG. The control unit 16 includes a variable tilt angle motor control unit (tilt angle control unit) 51 that controls the variable tilt angle motor 32, a weight drive motor control unit (weight position control unit) 52 that controls the weight drive motor 26, and a photographing apparatus. An imaging apparatus main body drive motor control unit (apparatus main body position control unit) 53 that controls the main body drive motor 42 is provided. These control units 51 to 53 can be configured by, for example, a common microcomputer or independent microcomputers.

  The operation unit 17 is provided with a first tilt angle variable switch 54, a second tilt angle variable switch 55, a first photographing device main body moving switch 56, and a second photographing device main body moving switch 57.

  The first tilt angle variable switch 54 varies the tilt angle command for rotating the tilt angle varying unit 18 in a direction (standing position) such that the subject's head on the bed 3 is above the foot. This is a switch for inputting to the motor control unit 51. The second variable tilt angle switch 55 is a switch for inputting, to the tilt angle variable motor control unit 51, a command for rotating the tilt angle variable unit 18 in the direction opposite to the standing direction (reverse tilt direction). is there.

  The first imaging apparatus main body moving switch 56 is a switch for inputting a command for moving the imaging apparatus main body 9 in the head direction of the subject on the bed 3 to the imaging apparatus main body drive motor control unit 53. The second imaging device main body moving switch 57 is a switch for inputting a command for moving the imaging device main body 9 toward the subject's foot on the bed 3 to the imaging device main body drive motor control unit 53.

  When the first or second variable tilt angle switch 54, 55 is operated, an operation start command is input from the variable tilt angle motor control unit 51 to the variable tilt angle motor 32, and the variable tilt angle motor 32 is driven. The inclination angle of the bed 3 is changed. At this time, a signal from the tilt encoder 38 is input to the weight drive motor control unit 52.

  On the other hand, when the first or second photographing device main body moving switches 56 and 57 are operated, an operation start command is input from the photographing device main body driving motor control unit 53 to the photographing device main body driving motor 42, and the photographing device main body driving motor When the camera 42 is driven, the photographing apparatus main body 9 moves in the longitudinal direction of the bed 3. At this time, a signal from the imaging apparatus main body encoder 45 is input to the weight drive motor control unit 52.

  The weight drive motor control unit 52 calculates the position of the photographing apparatus main body 9 based on a signal from the photographing apparatus main body encoder 45, and places the balance weight 11 in the longitudinal direction of the bed 3 so as to balance the moments around the rotation shaft 4. Move in the direction. At this time, a signal from the weight encoder 28 is fed back to the weight drive motor control unit 52.

  Further, when the weight drive motor control unit 52 detects that the rotation operation of the tilt angle variable unit 18 is started based on the information from the tilt encoder 38, the rotation direction and the tilt angle of the tilt angle variable unit 18 are detected. Is calculated. Further, the weight drive motor control unit 52 balances in the direction of approaching the end of the bed 3 that moves downward, regardless of the position of the photographing apparatus body 9, during the tilt angle changing operation of the bed 3. The weight 11 is moved.

  Thereby, when the tilt angle of the bed 3 is changed, the moment of the balance weight 11 acting in the direction of giving resistance to the operation is reduced, or the moment of the balance weight 11 is applied in the direction of assisting the operation. The load on the variable tilt angle motor 32 can be reduced.

  In this way, the movement of the photographing apparatus main body 9 in the longitudinal direction of the bed 3 and the movement of the balance weight 11 in the longitudinal direction of the bed 3 can be synchronized. Further, the rotation of the tilt angle varying unit 18 and the movement of the balance weight 11 in the longitudinal direction of the bed 3 can be synchronized.

  Signals from the first and second limit switches 29 and 30 are input to the weight drive motor control unit 52. Accordingly, the weight drive motor control unit 52 prevents the weight drive motor 26 from being driven in a direction in which the balance weight 11 goes out of the movable range.

  6 and 7 are side views showing a movement pattern of the balance weight 11 when the photographing apparatus main body 9 is moved. As shown in FIG. 6, when the imaging apparatus main body 9 is moved in the head direction of the subject, the weight drive motor control unit 52 moves the balance weight 11 in the direction of the subject's feet. In FIG. 6, F <b> 1 is the weight of the balance weight 11, and F <b> 2 is the weight of the tilt angle variable unit 18.

  As shown in FIG. 7, when the imaging apparatus main body 9 is moved in the direction of the subject's foot, the weight drive motor control unit 52 moves the balance weight 11 in the direction of the subject's head. Thereby, the moments around the rotation axis 4 can be balanced regardless of the position of the photographing apparatus main body 9 in the longitudinal direction of the bed 3.

  8 is a side view showing a state where the bed 3 (inclination angle varying unit 18) in FIG. 2 is being rotated in the standing direction, and FIG. 9 is a state in which the rotation of the bed 3 in FIG. 8 is stopped. FIG. When rotation of the bed 3 in the standing direction (inclination angle changing operation) is started, the weight drive motor control unit 52 moves to the lower end of the longitudinal direction of the bed 3, that is, the subject. The balance weight 11 is moved in a direction approaching the end of the foot side. When the rotation of the bed 3 is stopped, the weight drive motor control unit 52 returns the balance weight 11 to the position before the start of the inclination angle changing operation.

  10 is a side view showing a state in which the bed 3 (inclination angle varying unit 18) in FIG. 2 is being rotated in the reverse tilt direction, and FIG. 11 is a state in which the rotation of the bed 3 in FIG. 10 is stopped. FIG. When rotation of the bed 3 in the reverse tilt direction (tilt angle changing operation) is started, the weight drive motor control unit 52 is the end of the bed 3 that moves downward, that is, the subject. The balance weight 11 is moved in a direction approaching the end on the head side of the head. When the rotation of the bed 3 is stopped, the weight drive motor control unit 52 returns the balance weight 11 to the position before the start of the inclination angle changing operation.

  Further, when the first or second limit switch 29, 30 is operated during the movement of the balance weight 11, the weight drive motor control unit 52 stops the weight drive motor 26. As a result, when the inclination angle changing operation is performed in a state where the balance weight 11 is positioned at the stroke end, the balance weight 11 does not move beyond the movable range.

  FIG. 12 is a flowchart showing the operation of the weight drive motor controller 52 in response to the operation of the variable tilt angle switches 54 and 55 of FIG. When the processing of FIG. 12 is started, the weight drive motor control unit 52 monitors whether or not the first or second tilt angle variable switches 54 and 55 are turned on (steps S1 and S2).

  When the first tilt angle variable switch 54 that turns the bed 3 in the standing direction is turned on, it is confirmed whether or not the second limit switch 30 located on the subject's foot side is turned on ( Step S3). If the second limit switch 30 is on, the balance weight 11 is not moved and the first tilt angle variable switch 54 is waited for to turn off.

  If the second limit switch 30 is off, the balance weight 11 is moved in the direction of the subject's foot (step S4). After the movement of the balance weight 11 is started, the state of the second limit switch 30 is monitored (step S5), and the state of the first tilt angle variable switch 54 is monitored (step S6).

  If the first tilt angle variable switch 54 is turned off before the balance weight 11 reaches the position of the second limit switch 30, the balance weight 11 is stopped (step S7), and the opposite direction (the head direction of the subject) (Step S8).

  Thereafter, it is confirmed whether or not the balance weight 11 has reached the original position before the start of the tilt angle changing operation, that is, the position where the moments around the rotating shaft 4 are balanced (step S9), and the first or second. It is confirmed whether the tilt angle variable switches 54 and 55 are turned on (step S10).

  When the balance weight 11 reaches the original position, the balance weight 11 is stopped (step S11), and the process returns to step S1. If the first or second variable tilt angle switch 54 or 55 is turned on before the balance weight 11 reaches the original position, the balance weight 11 is stopped at that position (step S11). Return to S1.

  On the other hand, when the second limit switch 30 is turned on during the tilt angle changing operation, the balance weight 11 is immediately stopped (step S12), and the first tilt angle variable switch 54 is awaited to be turned off. (Step S13). Then, when the first tilt angle variable switch 54 is turned off, the operation proceeds to steps S8 to S11.

  The above is the operation when the bed 3 is rotated in the standing direction, but when rotating in the reverse tilt direction, that is, when the second tilt angle variable switch 55 is turned on, the head side of the subject. It is confirmed whether or not the first limit switch 29 located at is turned on (step S14). If the first limit switch 29 is on, the balance weight 11 is not moved and the second tilt angle variable switch 55 is awaited to be turned off.

  If the first limit switch 29 is off, the balance weight 11 is moved in the head direction of the subject (step S15). After the movement of the balance weight 11 is started, the state of the first limit switch 29 is monitored (step S16), and the state of the second tilt angle variable switch 55 is monitored (step S17).

  If the second variable tilt angle switch 55 is turned off before the balance weight 11 reaches the position of the first limit switch 29, the balance weight 11 is stopped (step S18), and the operations of steps S8 to S11 are performed. move on. If the first limit switch 29 is turned on during the tilt angle changing operation, the operation proceeds to steps S12 and S13.

  FIG. 13 is a flowchart showing the operation of the weight drive motor controller 52 in response to the operation of the photographing apparatus main body moving switches 56 and 57 of FIG. When the processing of FIG. 13 is started, the weight drive motor control unit 52 monitors whether or not the first or second imaging device body movement switches 56 and 57 are turned on (steps S21 and S22).

  Then, when the first imaging apparatus main body moving switch 56 for moving the imaging apparatus main body 9 in the head direction of the subject is turned on, the balance weight 11 is moved in the direction of the subject's feet (step S23). After the movement of the balance weight 11 is started, the state of the second limit switch 30 located on the subject's foot side is monitored (step S24), and the state of the first imaging device body movement switch 56 is monitored. (Step S25).

  If the first photographing apparatus body movement switch 56 is turned off before the balance weight 11 reaches the position of the second limit switch 30, the balance weight 11 is stopped (step S26), and the process returns to step S21. On the other hand, when the second limit switch 30 is turned on while moving the photographing apparatus main body 9, the balance weight 11 is immediately stopped (step S26), and the process returns to step S1.

  The above is the operation for moving the imaging apparatus main body 9 in the head direction of the subject. When the imaging apparatus main body 9 is moved in the foot direction, that is, when the second imaging apparatus main body moving switch 57 is turned on, the balance weight 11 is set. Is moved toward the head of the subject (step S27). After the movement of the balance weight 11 is started, the state of the first limit switch 29 located on the head side of the subject is monitored (step S28), and the state of the second tilt angle variable switch 55 is monitored (step S28). Step S29).

  If the second photographing apparatus main body moving switch 57 is turned off before the balance weight 11 reaches the position of the first limit switch 29, the balance weight 11 is stopped (step S26), and the process returns to step S21. On the other hand, when the first limit switch 29 is turned on while the photographing apparatus body 9 is being moved, the balance weight 11 is immediately stopped (step S26), and the process returns to step S21.

  In such an X-ray fluoroscopic apparatus, the weight driving motor control unit 52 moves the balance weight 11 in a direction approaching an end portion of the bed 3 that moves downward among both longitudinal ends of the bed 3 when the tilt angle of the bed 3 is changed. Therefore, the load applied to the variable tilt angle motor 32 during the tilt angle changing operation can be reduced.

  Thereby, the power saving and downsizing of the variable tilt angle motor 32 can be achieved, and for example, installation on a medical examination vehicle or the like can be facilitated.

  Further, when the tilt angle changing operation of the bed 3 is stopped, the balance weight 11 is returned to the position before the start of the tilt angle changing operation, so that the moment around the rotating shaft 4 can be balanced when the bed 3 is stationary.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. The configuration of the X-ray fluoroscopic apparatus of the second embodiment is the same as that of the first embodiment. Also in the second embodiment, during the tilt angle changing operation of the bed 3, the balance weight 11 is moved in the direction of approaching the end of the bed 3 that moves downward among the longitudinal ends of the bed 3. However, in the second embodiment, in the middle of the tilt angle changing operation, the balance weight 11 is reversed, and the operation of returning the balance weight 11 to the position before the start of the tilt angle changing operation is started.

  The timing for reversing the balance weight 11 during the tilt angle changing operation is set, for example, from a) the start of the tilt angle changing operation (when the first or second tilt angle variable switches 54 and 55 are turned on). When the time has passed, b) when the tilt angle of the bed changes from the start of the tilt angle changing operation, or c) when the balance weight 11 is moved by the set distance from the start of the tilt angle changing operation, etc. It is done.

  In addition, as a setting method of the set time of a), for example, a-1) a method of setting a fixed time regardless of the tilt angle and rotation direction of the bed 3 at the start of the tilt angle changing operation, or a- 2) A method of changing the set time according to the tilt angle and the rotation direction of the bed 3 at the start of the tilt angle changing operation can be mentioned.

  As the setting method of the above a-1), for example, an average duration of the tilt angle changing operation in the X-ray fluoroscopic apparatus is measured or estimated, and a predetermined ratio (for example, 50%) of the average duration The method of setting to is mentioned.

  As a setting method of the above a-2), for example, a method of setting a predetermined ratio (for example, 50%) of the time required to rotate the bed 3 by the remaining stroke in the rotation direction, or an inclination angle changing operation There is a method of setting to a predetermined ratio (for example, 50%) of the time required to move the balance weight 11 from the starting position to the end of the movable range.

  As a setting method of the setting angle of b), for example, there is a method of setting to a predetermined ratio (for example, 50%) of the rotatable angle from the current inclination angle of the bed 3.

  As a setting method of the set distance of c), for example, there is a method of setting a distance of a predetermined ratio (for example, 50%) for the remaining stroke in the movement direction of the balance weight 11.

  There is also a method of reversing the balance weight 11 when the balance weight 11 reaches the end of the movable range or a set position within the movable range (for example, the position of the rotating shaft 4).

  Here, in the first embodiment, the first or second tilt angle variable switches 54 and 55 are turned off or the first or second limit switches 29 and 30 are turned on during the tilt angle changing operation. Since the balance weight 11 is moved to a long time, it takes a long time to return the balance weight 11 to the original position if the duration of the tilt angle changing operation is long, and it may take a long time to perform the next inspection operation. is there.

  On the other hand, in the X-ray fluoroscopic apparatus of the second embodiment, the balance weight 11 is reversed during the tilt angle changing operation and returned to the position before the tilt angle changing operation is started. While reducing the load of the variable angle motor 32 to some extent, the time until the next inspection operation is performed can be shortened, and the inspection efficiency can be improved.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. In the first and second embodiments, it is assumed that the rotation center of the tilt angle variable unit 18, the center of gravity of the tilt angle variable unit 18, and the center of gravity of the balance weight 11 are on the same straight line. In the first and second embodiments, the influence of the change in the center of gravity for each subject (human body) is ignored.

  However, in reality, the three points of the rotation center of the tilt angle varying unit 18, the center of gravity of the tilt angle varying unit 18, and the center of gravity of the balance weight 11 are not necessarily on the same straight line. The position of the center of gravity changes.

  Therefore, in the third embodiment, movement control of the balance weight 11 is performed according to the following procedure. That is, in order to always maintain the moment balance regardless of how the tilt angle of the bed 3 changes, as described above, the center of rotation of the bed 3 and the center of gravity of the load need to be on the same straight line. is there. For this purpose, as shown in FIG. 14, the balance weight 11 must be movable not only in the longitudinal direction of the bed 3 but also in a direction (thickness direction) perpendicular to the surface of the bed 3 on which the subject is placed. . In FIG. 14, F <b> 1 is the weight of the balance weight 11, and F <b> 2 is the weight of the tilt angle variable unit 18.

  15 is a side view showing the main part of the X-ray fluoroscopic apparatus according to Embodiment 3, and FIG. 16 is a cross-sectional view taken along the line XVI-XVI of FIG. In this example, the base 21 is supported by first and second ball screws 61a and 61b. A first thickness direction drive motor 62 a is connected to the first ball screw 61. A second thickness direction drive motor 62b is connected to the second ball screw 61b.

  The first and second thickness direction drive motors 62a and 62b rotate the first and second ball screws 61a and 61b in synchronization. As a result, the balance weight 11 moves in the thickness direction of the bed 3 together with the base 21.

  FIG. 17 is an explanatory diagram illustrating a method for calculating the amount of movement of the balance weight 11 according to the third embodiment. In the third embodiment, a first pressure sensor 63 and a second pressure sensor 64 are installed inside the bed 3. The first pressure sensor 63 is arranged on the head side of the bed 3 in the longitudinal direction, here in the vicinity of the end of the head side. The second pressure sensor 64 is disposed on the foot side of the bed 3 in the longitudinal direction, here, in the vicinity of the end portion on the foot side.

  In FIG. 17, F1 is the weight of the balance weight 11, F2 is the weight of the tilt angle varying unit 18 that does not include the subject, F3 is the weight of the subject, and F2 ′ is the weight of the tilt angle varying unit 18 that includes the subject. .

  L1x is a horizontal distance from the center of gravity of the balance weight 11 before the subject is placed on the bed 3 to the center of rotation. L2x is a horizontal distance from the center of gravity of the tilt angle varying unit 18 before the subject is placed on the bed 3 to the center of rotation. L2y is a vertical distance from the center of gravity of the tilt angle varying unit 18 before the subject is placed on the bed 3 to the center of rotation.

  Further, L1x ′ is a horizontal distance from the center of gravity of the balance weight 11 after placing the subject on the bed 3 to the center of rotation. L1y ′ is the vertical distance from the center of gravity of the balance weight 11 after placing the subject on the bed 3 to the center of rotation. L2x ′ is a horizontal distance from the center of gravity of the tilt angle varying unit 18 after the subject is placed on the bed 3 to the center of rotation. L2y ′ is the vertical distance from the center of gravity of the tilt angle varying unit 18 after the subject is placed on the bed 3 to the center of rotation.

  Furthermore, L3x is the horizontal distance from the center of gravity of the subject to the center of rotation. L3y is the vertical distance from the center of gravity of the subject to the center of rotation.

Before the subject is placed on the bed 3, the moments around the rotation axis 4 are balanced, so the following equation is established.
F1L1x = F2L2x (1)

Further, in order to balance the moment around the rotation axis 4 even after the subject is placed on the bed 3, the following equation needs to be satisfied.
F1L1x ′ = F2′L2x ′ (2)

When the horizontal direction distance L1x ′ from the balance weight 11 to the rotation center is obtained from the equation (2), the following equation is obtained.
L1x ′ = (F2′L2x ′) / F1 (3)

Further, the horizontal center-of-gravity position L2x ′ of the tilt angle varying unit 18 after the subject is placed on the bed 3 is expressed by the following equation.
L2x ′ = (F2L2x + F3L3x) / (F2 + F3) (4)

Substituting equation (4) into equation (3) yields:
L1x ′ = (F2L2x + F3L3x) / F1 (5)

Further, the vertical center of gravity position L1y ′ of the balance weight 11 after placing the subject on the bed 3 is expressed by the following equation.
L1y ′ = L1x ′ (L2y ′ / L2x ′) (6)

Furthermore, the vertical direction gravity center position L2y ′ of the tilt angle varying unit 18 after the subject is placed on the bed 3 is expressed by the following equation.
L2y ′ = (F2L2y + F3L3y) / (F2 + F3) (7)

Substituting Equation (4), Equation (5), and Equation (6) into Equation (7) yields the following equation:
L1y ′ = (F2L2y + F3L3y) / F1 (8)

  According to the above formulas (5) and (8), even after the subject is placed on the bed 3, the moment around the rotation axis 4 is balanced, and the center of gravity, the rotation center, and the balance of the tilt angle variable unit 18 are balanced. The movement amount of the balance weight 11 for arranging the three points of the center of gravity of the weight 11 on the same straight line can be calculated.

  FIG. 18 is a block diagram showing the main part of the X-ray fluoroscopic apparatus according to the third embodiment. Signals from the first and second pressure sensors 63 and 64 are input to the weight drive motor control unit 52. The weight drive motor control unit 52 controls the weight drive motor 26 and the first and second thickness direction drive motors 62a and 62b based on signals from the first and second pressure sensors 63 and 64.

  The weight driving motor control unit 52 arranges the balance weight 11 according to the position of the imaging apparatus main body 9 in the longitudinal direction of the bed 3 when the subject is not placed on the bed 3. That is, the weight drive motor control unit 52 balances the moments around the rotation shaft 4 and positions the center of gravity of the tilt angle variable unit 18, the center of rotation, and the center of gravity of the balance weight 11 on the same straight line.

  In this state, when the subject is placed on the bed 3, the weight drive motor control unit 52 measures the weight of the subject and the longitudinal center of gravity position of the bed 3 based on the signals from the pressure sensors 63 and 64. A command for moving the balance weight 11 in the longitudinal direction of the bed 3 is output to the weight drive motor 26, and a command for moving the balance weight 11 in the thickness direction of the bed 3 is provided in the first and second thicknesses. It outputs to the direction drive motors 62a and 62b.

  FIG. 19 is a flowchart showing an outline of the operation of the weight drive motor control unit 52 when the bed 3 of the third embodiment is stationary. The weight drive motor control unit 52 monitors whether or not a load is applied to the bed 3 based on signals from the first and second pressure sensors 63 and 64 (step S31).

  When a load is applied to the bed 3, the movement amount of the balance weight 11 is calculated as described above (step S32), and the balance weight 11 is moved (step S33). Thereafter, it is confirmed whether or not the movement of the balance weight 11 is completed (step S34), and when the movement is completed, the balance weight 11 is stopped (step S35). Other configurations and operations are the same as those in the first embodiment.

  In such an X-ray fluoroscopic apparatus, the balance weight 11 can also be moved in the thickness direction of the bed 3, and the weight drive motor control unit 52 is based on signals from the pressure sensors 63 and 64. Is also moved in the thickness direction of the bed 3, so that the balance of moment can always be maintained no matter how the tilt angle of the bed 3 changes with the subject placed thereon.

Note that only the movement control of the balance weight 11 when the bed 3 is stationary shown in the third embodiment is performed separately from the movement control of the balance weight 11 during the tilt angle changing operation shown in the first and second embodiments. It is also possible.
The mechanism for moving the balance weight 11 in the longitudinal direction of the bed 3 is not limited to the above example, and may be moved using, for example, a linear motor, a hydraulic cylinder, an air cylinder, or the like.

  3 Bed, 4 Rotating shaft, 6 X-ray tube device, 8 X-ray detector, 9 Imaging device body, 11 Balance weight, 52 Weight drive motor control unit (weight position control unit), 63 First pressure sensor, 64 Second pressure sensor.

Claims (4)

A bed whose inclination angle can be changed by rotating around a rotation axis,
An imaging apparatus main body having an X-ray tube device and an X-ray detector and movable in the longitudinal direction of the bed;
A balance weight that can move in the longitudinal direction of the bed independently of the imaging apparatus body, and a weight that moves the balance weight in the longitudinal direction of the bed according to the position of the imaging apparatus body in the longitudinal direction of the bed With a position controller
X-ray fluoroscopy, wherein the weight position control unit moves the balance weight in a direction approaching an end portion that moves downward among both longitudinal end portions of the bed during an operation of changing the tilt angle of the bed Shooting device.   The X-ray fluoroscopic imaging apparatus according to claim 1, wherein the weight position control unit returns the balance weight to a position before the start of the tilt angle changing operation when the tilt angle changing operation of the bed is stopped.   The X-ray fluoroscopic apparatus according to claim 1, wherein the weight position control unit reverses the balance weight in the middle of the tilt angle changing operation of the bed and returns the balance weight to a position before starting the tilt angle changing operation. The balance weight is movable in the thickness direction of the bed,
The bed is provided with a plurality of pressure sensors,
The weight position control unit moves the balance weight also in the thickness direction of the bed based on a signal from the pressure sensor, according to any one of claims 1 to 3. The X-ray fluoroscopic apparatus described.

Images