JP2020074978A - X-ray fluoroscopic apparatus - Google Patents

Abstract

To prevent an ineffective exposure of a subject when determining an appropriate irradiation condition of X-ray pulse.SOLUTION: An X-ray fluoroscopic apparatus 100 includes: an X-ray tube 1 for irradiating repeated X-ray pulse at a predefined pulse rate to a subject 101; an X-ray detector 10 for detecting the X-ray that has penetrated through the subject 101; a distance measuring part 6 provided in the vicinity of the X-ray tube 1 and measuring a first distance d1 to a body surface of the subject 101; and a system control part 14 that determines the irradiation condition of the repeatedly irradiated X-ray pulse according at least to the first distance d1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an X-ray fluoroscopic imaging apparatus, and more particularly to a technique for performing X-ray fluoroscopic imaging according to distance information from an X-ray irradiation unit to a body surface.

  X-ray image diagnosis methods include general radiography such as chest X-ray photography in which the subject is irradiated with X-rays once to generate a still image, and the subject is repeatedly irradiated with X-rays at a predetermined irradiation rate. There is a fluoroscopic imaging that generates a moving image.

  As an X-ray imaging apparatus for performing general imaging, an apparatus that starts time measurement at the start of imaging and ends the imaging when a predetermined time elapses, or detects the integrated amount of X-rays by an X-ray detector such as an ion chamber at the start of imaging. For the first time, there is known a device or the like that terminates shooting when the integrated amount exceeds a predetermined value.

  Further, as an example of a system provided with an X-ray imaging apparatus, in Patent Document 1, an optical sensor is used to measure a distance from the optical sensor to the body surface of the subject and a distance from the optical sensor to the table, A technique is disclosed in which the body thickness is calculated from the difference and the X-ray imaging condition (tube voltage or tube current of the X-ray tube) is set from the calculated body thickness.

  On the other hand, in an X-ray fluoroscopic imaging apparatus that performs fluoroscopic imaging, first, an X-ray irradiating unit repeatedly irradiates the subject with X-ray pulses at a predetermined rate, and the X-rays transmitted through the subject are detected by an X-ray detector. Then, the moving image is displayed by generating the detection result as an image and displaying it in time series. The X-ray dose detected at this time is fed back to the X-ray irradiation unit, and it is determined whether or not the irradiation amount is appropriate. If the irradiation amount is not appropriate, the irradiation condition of the X-ray (transparent X-ray condition) such as the irradiation pulse rate is changed, and the irradiation of the transparent X-ray and the condition change are repeated until the irradiation intensity becomes appropriate. For example, when the intensity of the fluoroscopic X-ray is high, the fluoroscopic X-ray is emitted at a lower intensity than the previous time when the fluoroscopic X-ray is irradiated next time. As a result, an appropriate fluoroscopic X-ray irradiation amount is set. Further, the irradiation intensity (imaging X-ray condition) of the imaging X-ray is determined based on the appropriate irradiation amount of the transparent X-ray.

JP, 2017-136300, A

  In the fluoroscopic imaging, as described above, it is impossible to determine whether or not the fluoroscopic X-rays irradiated to the subject have an appropriate intensity until the fluoroscopic X-rays are irradiated. After the first X-ray pulse is irradiated, the irradiation intensity of the appropriate X-ray pulse is reached after a lapse of a predetermined time, but the subject repeats the irradiation of the X-ray pulse until the appropriate intensity of the fluoroscopic X-ray is reached. You will receive it. The fluoroscopic X-ray image obtained until the appropriate irradiation intensity is determined is an inappropriate X-ray image for radiogram interpretation, and is an invalid exposure for the subject.

  As described above, the problem of ineffective exposure occurring until obtaining an appropriate fluoroscopic X-ray condition is peculiar to fluoroscopic X-ray imaging. Therefore, preventing it is the system of Patent Document 1 for performing general radiography. Is not considered in.

  An object of the present invention is to prevent invalid exposure of a subject when determining an appropriate irradiation condition of an X-ray pulse.

  An X-ray fluoroscopic imaging apparatus of the present invention includes an X-ray irradiator that repeatedly irradiates a subject with X-ray pulses at a predetermined pulse rate, an X-ray detector that detects X-rays that have passed through the subject, and an X-ray detector. A distance measuring unit that is provided in the vicinity of the X-ray irradiation unit and measures the first distance to the body surface of the subject, and determines the irradiation condition of the repeatedly irradiated X-ray pulse according to at least the first distance. And a system control unit.

  According to the present invention, it is possible to prevent invalid exposure of a subject when determining an appropriate irradiation condition of an X-ray pulse.

FIG. 3 is a block diagram showing the overall configuration of an X-ray fluoroscopic imaging apparatus 100. 3 is a block diagram showing the configuration of a system control unit 14 according to the first embodiment. FIG. 3 is a flowchart of processing executed by the fluoroscopic imaging apparatus 100 according to the first embodiment. Explanatory drawing which shows the relationship of distance d1, forbidden distance d-dis, and permission distance d-ena. 6 is a block diagram showing the configuration of a system control unit 14 according to the second embodiment. FIG. 7 is a flowchart of processing executed by the X-ray fluoroscopic imaging apparatus 100 according to the second embodiment. 6 is a block diagram showing the configuration of a system control unit 14 of Embodiment 3. FIG. 9 is a flowchart of processing executed by the fluoroscopic imaging apparatus 100 according to the third embodiment. The flowchart which shows the fluctuation determination process which the distance fluctuation monitoring part 18 performs. Explanatory drawing which shows the fluctuation | variation of distance d1, and the relationship of permissible fluctuation range d-rge. 7 is a block diagram showing the configuration of a system control unit 14 of Embodiment 4. FIG. 9 is a flowchart of processing executed by the X-ray fluoroscopic imaging apparatus 100 according to the fourth embodiment. FIG. 16 is a block diagram showing the configuration of a system control unit 14 according to the fifth embodiment. 6 is a graph showing the relationship between the variation of the distance d1 and the allowable variation range d-rge. 9 is a flowchart of processing executed by the fluoroscopic imaging apparatus 100 according to the fifth embodiment. (A) Explanatory drawing which shows a partial structure of the X-ray fluoroscopic imaging apparatus 100 at the time of vertical imaging, (B) Explanatory drawing which shows a partial structure of the X-ray fluoroscopic imaging apparatus 100 at the time of oblique imaging. 9 is a flowchart of processing executed by the fluoroscopic imaging apparatus 100 according to the sixth embodiment. 9 is a flowchart of processing executed by the fluoroscopic imaging apparatus 100 according to the seventh embodiment.

  Hereinafter, the X-ray fluoroscopic imaging apparatus 100 of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, an X-ray fluoroscopic imaging apparatus 100 includes an X-ray irradiation unit (X-ray tube) 1 that repeatedly irradiates a subject with an X-ray pulse at a predetermined pulse rate, and an X-ray that passes through the subject. An X-ray detector 10 for detecting X-rays; a distance measuring unit 6 provided near the X-ray tube 1 for measuring a first distance d1 to the body surface of the subject 101 of the X-ray tube 1; The system control unit 14 determines the irradiation condition (transparent X-ray condition) of the X-ray pulse repeatedly irradiated according to the distance d1 of 1.

  Since the X-ray fluoroscopic imaging apparatus 100 of the present invention can determine an appropriate fluoroscopic X-ray condition according to the distance d1, irradiation of the fluoroscopic X-ray and fluoroscopic X-ray to determine an appropriate fluoroscopic X-ray condition. There is no need to repeat changing conditions. This makes it possible to prevent invalid exposure of the subject when determining an appropriate fluoroscopic X-ray condition.

  Further, the X-ray fluoroscopic imaging apparatus 100 determines the radiographic X-ray condition determining the irradiation intensity (radioactive X-ray condition) of the radiographic X-ray when performing X-ray imaging from the fluoroscopic X-ray condition determined by the system control unit 14. Part (high voltage generator 2 and X-ray controller 3), X-ray movable diaphragm 4 for setting the X-ray irradiation area for the subject 101, and X-ray movable diaphragm controller 5 for controlling the X-ray movable diaphragm 4. A distance measuring unit control device 7 that controls the distance measuring unit 6, a table 8 on which the subject 101 is placed, and a support mechanism control device 9 that controls the support mechanism of the X-ray fluoroscopic imaging apparatus including the table 8. ..

  Further, the X-ray fluoroscopic imaging apparatus 100 converts an X-ray signal detected by the X-ray detector 10 into image data into an X-ray detector control device 11 and image data converted by the X-ray detector control device 11. An image processing device 12 that performs image processing, a display device 13 that displays an X-ray image, a message, and the like, and an imaging switch 24 that issues an X-ray imaging command to the system control unit 14 by an operator's operation. .. Further, it is preferable that the X-ray fluoroscopic imaging apparatus 100 includes an X-ray fluoroscopic switch that switches between permission and prohibition of irradiation of the fluoroscopic X-rays by an operator's operation.

  The X-ray tube 1 emits X-rays when a high voltage is applied from a high voltage generator 2 controlled by the X-ray controller 3, and the table 8 is placed on the mounting surface 8b of the subject 101. It is supported by a support mechanism (not shown) so that it can be moved in parallel and can be moved up and down. Further, since this support mechanism rotatably supports the X-ray tube 1 with respect to the table 8, the X-ray fluoroscopic imaging apparatus 100 is configured so that the angle of the X-ray irradiated to the subject 101 (oblique incidence). Angle) can be changed.

  The distance measuring unit 6 is fixed at a position where the distance d1 to the body surface can be detected. Specifically, the distance measuring unit 6 is fixed to the lower part of the X-ray movable diaphragm 4 so as to face the front surface (the surface viewed from the abdominal side) of the subject 101 lying on the table 8 on his back. Since the X-ray tube 1 is movable and rotatable as described above, the distance measuring unit 6 is movable and rotatable integrally with the X-ray tube 1 and the X-ray diaphragm 4.

  The distance measuring unit 6 is configured by a detector that transmits and receives, for example, infrared rays and ultrasonic waves to detect the distance d1 by the TOF (Time Of Flight) method, and notifies the system control unit 14 of information on the detected distance d1. The distance measuring unit 6 may use an infrared array sensor in which a plurality of detection elements for detecting infrared rays are arranged in a two-dimensional array.

  The support mechanism controller 9 controls the operation of a support mechanism that supports the X-ray tube 1 and the table 8 to control the position and inclination of the X-ray tube 1 and the table 8. Further, the support mechanism control device 9 constantly calculates the second distance d2 from the X-ray tube 1 to the mounting surface 8b of the table 8, and notifies the system control unit 14 of the information on the calculated distance d2. .. Further, the support mechanism control device 9 detects the oblique insertion angle of the X-ray tube 1 with respect to the direction orthogonal to the mounting surface 8b of the table 8 at any time, and notifies the system control unit 14 of the information on the detected oblique insertion angle. Good. This oblique insertion angle is used in the processing of Embodiment 6 described later.

  The system control unit 14 controls the operation of each unit of the fluoroscopic imaging apparatus 100. For example, the system control unit 14 determines the fluoroscopic X-ray condition according to the distance information in the processing of Embodiments 1 to 7 described later, and the information of the determined fluoroscopic X-ray condition is used as the high voltage generator 2 and the X-ray control device 3. To notify. The fluoroscopic X-ray condition determined by the system control unit 14 according to the distance information is at least one of the pulse rate of the X-ray pulse and the propriety of irradiation of the X-ray pulse. Further, the fluoroscopic X-ray condition determined by the system control unit 14 may also include the irradiation intensity of the X-ray pulse (tube voltage, tube current).

  Upon receiving the fluoroscopic X-ray condition, the high-voltage generator 2 causes the X-ray tube 1 to emit an X-ray pulse at a predetermined pulse rate according to the notified fluoroscopic X-ray condition. Further, the high voltage generator 2 that has received the fluoroscopic X-ray condition further determines the radiographic X-ray condition from the fluoroscopic X-ray condition, and when the radiographic switch 24 is pressed, the radiographic X-ray is emitted from the X-ray tube 1. Let

  In this embodiment, the function of the system control unit 14 can be realized by a computer including a CPU and a memory. The calculation and control programs may be stored in the storage device in advance, or may be fetched from the outside and uploaded by the CPU to be executed. Note that all or part of the functions of the calculation unit can be realized by hardware such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field Programmable Gate Array).

  The X-ray detector 10 is arranged at a position facing the X-ray tube 1, and is constituted by arranging a plurality of detection elements for detecting X-rays in a two-dimensional array, for example. The X-ray detector 10 detects the X-rays emitted from the X-ray tube 1 and transmitted through the subject 101, and generates an X-ray signal corresponding to the detected X-ray dose. Specifically, the X-rays detected by the X-ray detector 10 are accumulated as electric charges in a storage capacitor (not shown) for each pixel, and generate an X-ray signal based on the electric charges accumulated for each pixel. The X-ray signal generated by the X-ray detector 10 is transmitted to the X-ray detector control device 11 and converted into image data by the X-ray detector control device 11. The converted image data is output to the image processing device 12 by the X-ray detector control device 11.

  The image processing device 12 performs image processing on the image data input from the X-ray detector control device 11 according to an instruction from the system control unit 14. The image processing device 12 saves the image processing result in a storage device (not shown) and displays it on the display device 13.

  Further, in the image processing device 12, the examination site of the subject 101 to be irradiated with X-rays and the type of the procedure to be performed for each examination site are registered in advance, and the examination site to be performed and the type of the procedure can be changed. When it is recognized, the system control unit 14 is notified of a change in the examination site or the type of procedure.

  Hereinafter, processing of the X-ray fluoroscopic imaging apparatus 100 of Embodiments 1 to 7 will be described. The configuration of the X-ray fluoroscopic apparatus 100 described above is common to the following first to seventh embodiments.

<Embodiment 1>
The processing of the X-ray fluoroscopic apparatus 100 according to the first embodiment will be described with reference to FIGS. In the first embodiment, the system control unit 14 calculates the distance Δd from the mounting surface 8b of the table 8 to the body surface which is the X-ray irradiation site, and determines the fluoroscopic X-ray condition from the distance Δd.

[Configuration of system control unit 14]
As shown in FIGS. 1 and 2, the system control unit 14 according to the first embodiment includes a distance calculation unit 15 that calculates the distance Δd using the distance d1 and a fluoroscopy X that determines the fluoroscopic X-ray condition according to the distance d1. The X-ray condition determining unit 16 and the X-ray condition change notifying unit 17 that notifies the high-voltage generator 2 and the X-ray controller 3 of the determined fluoroscopic X-ray condition are provided.

  The distance measuring unit control unit 7 calculates the third distance d3 from the X-ray tube 1 to the distance measuring unit 6 at any time, and transmits information on the calculated distance d3 to the distance calculating unit 15. The distance calculator 15 calculates the distance Δd by subtracting a value obtained by adding the distance d3 to the distance d1 from the distance d2 as in the following Expression 1.

(Equation 1)
Δd = d2- (d1 + d3) (1)

[Processing procedure]
Hereinafter, the processing procedure performed by the X-ray fluoroscopic apparatus 100 of the first embodiment will be described with reference to the flow of FIG.

[Step S11]
As shown in FIG. 3, when the process of the X-ray fluoroscopic imaging apparatus 100 is started, the distance measuring unit 6 detects the distance d1 to the body surface of the examination site of the subject 101 who radiates X-rays. The distance measurement detection control device 7 notifies the distance calculation unit 15 of the information on the distance d1 calculated by the distance measurement unit 6. At the start of the process, initial values of fluoroscopic X-ray conditions (pulse rate, tube voltage of the X-ray tube 1, tube current of the X-ray tube 1, etc.) are set in the high voltage generator 2 and the X-ray controller 3. ing.

[Step S12]
The support mechanism control device 9 calculates the distance d2 from the X-ray tube 1 to the placement surface 8b of the subject 101 of the table 8 at any time. The support mechanism control device 9 notifies the distance calculation unit 15 of the calculated distance d2.

[Step S13]
The distance calculation unit 15 calculates the distance Δd from the above-described formula 1 using the distance d1 received from the distance measuring unit 6, the distance d2 received from the support mechanism control device 9, and the distance d3. The distance calculation unit 15 notifies the fluoroscopic X-ray condition determination unit 16 of the information on the calculated distance Δd.

[Step S14]
The fluoroscopic X-ray condition determination unit 16 refers to a table of predetermined fluoroscopic X-ray conditions (pulse rate, tube voltage of the X-ray tube 1, and tube current of the X-ray tube 1) and receives it from the distance calculation unit 15. The fluoroscopic X-ray condition corresponding to the distance Δd is determined from the information on the distance Δd. Note that the fluoroscopic X-ray condition determining unit 16 may determine the fluoroscopic X-ray condition by referring to different fluoroscopic X-ray condition tables according to the examination site of the subject 101. The fluoroscopic X-ray condition determination unit 16 notifies the X-ray condition change notification unit 17 of the determined fluoroscopic X-ray condition.

[Step S15]
The X-ray condition change notification unit 17 notifies the high-voltage generator 2 and the X-ray control device 3 of the determined fluoroscopic X-ray condition and instructs the high-voltage generator 2 and the X-ray controller 3 to change the fluoroscopic X-ray condition.

[Step S16]
The high-voltage generator 2 and the X-ray controller 3 change the set fluoroscopic X-ray condition to the fluoroscopic X-ray condition determined by the X-ray condition change notification unit 17.

[Step S17]
The high voltage generator 2 and the X-ray controller 3 refer to a table in which fluoroscopic X-ray conditions and radiographic X-ray conditions (tube voltage of the X-ray tube 1, tube current of the X-ray tube 1, etc.) are associated in advance. , The imaging X-ray condition is determined from the fluoroscopic X-ray condition.

[Step S18]
The system control unit 14 determines whether the user has turned on the X-ray fluoroscopic switch. When the see-through switch is ON, the system control unit 14 notifies the high-voltage generator 2 and the X-ray controller 3 that the see-through switch is ON.

[Step S19]
The high voltage generator 2 and the X-ray controller 3 send an instruction to the X-ray tube 1 to irradiate the X-ray pulse under the fluoroscopic X-ray condition determined by the fluoroscopic X-ray condition determining unit 16. Thereby, the fluoroscopic X-ray irradiation is started under the fluoroscopic X-ray conditions (pulse rate, tube voltage of the X-ray tube 1, and tube current of the X-ray tube 1) set for the subject 101, and pulse fluoroscopy is started. To be done.

[Step S20]
When the pulse fluoroscopy is started, the subject 101 is repeatedly irradiated with X-ray pulses to generate a moving image. Specifically, first, the X-ray tube 1 irradiates the subject 101 with an X-ray pulse under the fluoroscopic X-ray condition determined by the fluoroscopic X-ray condition determining unit 16. The X-rays that have passed through the subject 101 are accumulated as electric charges for each pixel of the X-ray detector 10. The X-ray detector 10 generates an X-ray signal for each pixel based on the accumulated charges and sends it to the X-ray detector control device 11. The X-ray detector control device 11 converts the received X-ray signal into image data, and outputs the converted image data to the image processing device 12. The image processing device 12 performs image processing on the image data input from the X-ray detector control device 11. The result of image processing by the image processing device 12 is stored in a storage device (not shown) and displayed on the display device 13. In pulse fluoroscopy, since X-ray pulses are repeatedly emitted from the X-ray tube 1, the image displayed on the display device 13 becomes a moving image.

[Step S21]
After pulse fluoroscopy in step S20 or when the fluoroscopy switch is OFF in step S18, the system control unit 14 determines whether the imaging switch 24 is pressed by a doctor or the like in step S21. When the imaging switch 24 is ON, the system control unit 14 notifies the high voltage generator 2 and the X-ray controller 3 that the imaging switch 24 is ON. The process of the X-ray fluoroscopic imaging apparatus 100 proceeds to the next step S22 for performing X-ray imaging. When the imaging switch 24 is OFF, the X-ray fluoroscopic imaging apparatus 100 does not perform X-ray imaging and returns to step S11.

[Step S22]
When the imaging switch 24 is pressed by a doctor or the like, X-ray imaging is started. The high voltage generator 2 and the X-ray control device 3 send an instruction to the X-ray tube 1 to irradiate the photographing X-ray under the determined photographing X-ray condition. As a result, imaging X-ray irradiation is started for the subject 101, and X-ray imaging is started.

[Step S23]
The X-ray detector 10 detects the imaged X-rays that are irradiated from the X-ray tube 1 to the subject 101 and transmitted through the subject 101. The X-ray detector 10 generates an X-ray signal for each pixel based on the accumulated charges and sends it to the X-ray detector control device 11. The X-ray detector control device 11 converts the received X-ray signal into image data, and outputs the converted image data to the image processing device 12. The image processing device 12 performs image processing on the image data input from the X-ray detector control device 11. The result of image processing by the image processing device 12 is stored in a storage device (not shown) and displayed on the display device 13. Note that the X-ray fluoroscopic imaging apparatus 100 may shoot a single still image, or may continuously shoot while the imaging switch 24 is being pressed.

  In the first embodiment, when step S23 ends, the process returns to step S11, and these steps S11 to S23 are repeated.

  As described above, in the first embodiment, the distance calculation unit 15 calculates the distance Δd from the distances d1 to d3, and the fluoroscopic X-ray condition determination unit 16 determines the fluoroscopic X-ray condition from the distance Δd. Therefore, it is optimal according to the distance Δd. The X-ray pulse can be emitted after determining the transparent X-ray condition. As a result, the X-ray pulse can be emitted under the optimum fluoroscopic X-ray condition according to the body thickness of the subject 101 lying on the table 8.

<Embodiment 2>
Hereinafter, processing of the X-ray fluoroscopic imaging apparatus 100 according to the second embodiment will be described with reference to FIGS. In the second embodiment, the X-ray fluoroscopic imaging apparatus 100 monitors the variation of the distance d1 and determines whether the X-ray irradiation prohibition distance d-dis and the permission distance d-ena are predetermined, and the X-ray radiography is performed according to the relationship between the distance d1. Performs processing to permit or prohibit the irradiation of line pulses.

  For example, as shown in FIG. 4, when a medical staff S, such as a doctor, performs a procedure and a support for the subject 101 on the table 8, the head of the medical staff S and the X-ray tube 1 and the subject 101 It may get in between. When the head of the medical staff S or the like enters between the X-ray tube 1 and the subject 101, the distance d1 detected by the distance measuring unit 6 is smaller than the distance to the body surface of the subject 101. . Therefore, in the second embodiment, the X-ray fluoroscopic imaging apparatus 100 emits an X-ray pulse when the distance d1 is equal to or greater than the permitted distance d-ena, and emits an X-ray pulse when the distance d1 is equal to or less than the prohibited distance d-dis. By prohibiting the above, the medical staff S is prevented from being irradiated with the X-ray pulse.

  A threshold for prohibiting the irradiation of the X-ray pulse is set to the prohibited distance d-dis. The prohibited distance d-dis is preferably set based on, for example, the distance between the X-ray tube and the skin defined by the medical law.

  In the permitted distance d-ena, a distance larger than the prohibited distance is set in order to irradiate X-rays more safely. It is preferable that the permission distance d-ena be set to a value that prohibits the irradiation of the X-ray pulse when it is clearly predicted that the distance is not the distance to the body surface of the subject 101.

  As shown in FIG. 5, the system control unit 14 of the second embodiment includes, in addition to the distance calculation unit 15, a distance change monitoring unit 18 that monitors a change in the distance d1 and a prohibited distance d-dis and X of X-ray irradiation. An X-ray irradiation prohibition / permission distance setting unit 19 in which a permitted distance d-ena for the irradiation of rays is stored in advance.

  Hereinafter, a processing procedure performed by the fluoroscopic imaging apparatus 100 in the second embodiment will be described. The processing procedure of the second embodiment is the same as that of the first embodiment up to step S13 in which the distance calculation unit 15 calculates the distance Δd from the distances d1 to d3.

[Step S24]
As shown in FIG. 6, in step S24, the distance variation monitoring unit 18 records the distances d1 and d2 received by the distance calculation unit 15 and the distance Δd calculated by the distance calculation unit 15. The X-ray irradiation prohibition / permission distance setting unit 19 notifies the distance variation monitoring unit 18 of the preset X-ray irradiation prohibition distance d-dis and the X-ray irradiation permission distance d-ena. The distance variation monitoring unit 18 determines whether or not the distance d1 is equal to or less than the X-ray irradiation prohibited distance d-dis (d1 ≦ d-dis). The process of the X-ray fluoroscopic apparatus 100 proceeds to step S25 when the distance d1 is equal to or less than the X-ray irradiation prohibited distance d-dis, and proceeds to step S26 when the distance d1 is greater than the X-ray irradiation prohibited distance d-dis.

[Step S25]
If the distance d1 is equal to or less than the X-ray irradiation prohibited distance d-dis in step S24, the distance variation monitoring unit 18 determines that the distance d1 from the X-ray tube 1 to the body surface is too short, and prohibits the X-ray irradiation. decide. Then, the distance variation monitoring unit 18 notifies the X-ray irradiation prohibition / permission notifying unit 20 of the prohibition of X-ray irradiation.

[Step S26]
If the distance d1 is greater than the X-ray irradiation prohibited distance d-dis in step S24, the distance variation monitoring unit 18 determines whether the distance d1 is equal to or greater than the X-ray irradiation permitted distance d-ena (d1 ≧ d-ena). to decide. The process of the X-ray fluoroscopic imaging apparatus 100 proceeds to step S27 if the distance d1 is the X-ray irradiation permission distance d-ena or more. When the distance d1 is less than the X-ray irradiation permission distance d-ena, the process proceeds to step S27.

[Step S27]
When the distance d1 is equal to or greater than the X-ray irradiation permission distance d-ena in step S26, the distance variation monitoring unit 18 determines that the distance d1 from the X-ray tube 1 to the body surface is sufficiently secured and the X-ray irradiation is performed. Determine the permission of. Then, the distance variation monitoring unit 18 notifies the X-ray irradiation prohibition / permission notifying unit 20 of the permission of X-ray irradiation.

[Step S28]
When the distance d1 is less than the X-ray irradiation permission distance d-ena in step S26, the distance variation monitoring unit 18 determines that the distance d1 from the X-ray tube 1 to the body surface is insufficient and the X-ray irradiation is not performed. Determine the ban. Then, the distance variation monitoring unit 18 notifies the X-ray irradiation prohibition / permission notifying unit 20 of the prohibition of X-ray irradiation.

[Step S29]
The X-ray irradiation prohibition / permission notifying unit 20 notifies the high voltage generator 2 and the X-ray controller 3 of the notification of the prohibition or permission of the X-ray irradiation received from the distance variation monitoring unit 18. The high voltage generator 2 continues to emit the X-ray pulse while receiving the notification of permission of the X-ray irradiation, and stops the irradiation of the X-ray pulse when receiving the notice of prohibition of the X-ray irradiation. Send instructions to the X-ray tube 1. In the second embodiment, when step S29 ends, the process returns to step S11, and these steps S11 to S29 are repeated.

  As described above, in the second embodiment, the variation of the distance d1 detected by the distance measuring unit 6 can be monitored, and the prohibition or permission of X-ray irradiation can be determined according to the distance d1. For example, when the subject 101 approaches the X-ray tube 1 by moving on the table 8 and the distance d1 approaches the X-ray irradiation permission distance d-ena, the X-ray irradiation is prohibited. It is possible to prevent invalid exposure of the worker 101. Further, when the head of the medical staff S or the like enters between the X-ray tube 1 and the subject 101, irradiation of X-rays is prohibited, so that the medical staff S can be prevented from being exposed. Further, even when the cleaning staff who cleans the table 8 after the procedure or the inspection enters between the X-ray tube 1 and the table 8, the exposure of the cleaning staff can be prevented.

<Embodiment 3>
Hereinafter, processing of the X-ray fluoroscopic apparatus 100 according to the third embodiment will be described with reference to FIGS. In the X-ray fluoroscopic imaging apparatus 100 according to the third embodiment, the distance measuring unit 6 detects the time (stop time) t at which the subject 101 (variation in the distance d1) should be stopped in order to emit the X-ray pulse. The process of permitting or prohibiting the irradiation of the X-ray pulse is performed depending on whether or not the variation of the distance d1 is within the allowable variation amount d-rge.

  As shown in FIG. 7, the system control unit 14 of the third embodiment, in addition to the distance calculation unit 15, prohibits or permits the X-ray irradiation with the distance fluctuation monitoring unit 18 that constantly monitors the fluctuation of the distance d1. The X-ray irradiation prohibition / permission notifying unit 20 for notifying the high voltage generator 2 and the X-ray control device 3, the allowable fluctuation amount setting unit 21 in which the fluctuation amount d-rge is preset, and the stop time t are preset. The variable stop time setting unit 22 is provided.

  The distance variation monitoring unit 18 sends a notification permitting the X-ray irradiation to the X-ray irradiation prohibition / permission notifying unit 20 while the distance d1 is within the range of the variation amount d-rge, and the distance d1 changes the variation amount d-rge. If it is out of the range, the X-ray irradiation prohibition / permission notifying unit 20 is notified that the X-ray irradiation is permitted.

  Here, a procedure in which the system control unit 14 controls prohibition or permission of X-ray irradiation according to the variation of the distance d1 in the third embodiment will be described with reference to FIG. The processing procedure of the third embodiment is the same as that of the first embodiment up to step S13 in which the distance calculation unit 15 calculates the distance Δd from the distances d1 to d3.

[Step S34]
The distance variation monitoring unit 18 records the distances d1 and d2 received by the distance calculation unit 15 and the distance Δd calculated by the distance calculation unit 15. The allowable fluctuation amount setting unit 21 notifies the distance fluctuation monitoring unit 18 of the allowable fluctuation amount d-rge. The fluctuation stop time setting unit 22 notifies the distance fluctuation monitoring unit 18 of the stop time t. The distance variation monitoring unit 18 determines whether or not the distance d1 is within the allowable variation amount d-rge during the stop time t. The process executed by the distance variation monitoring unit 18 in step S34 will be described in detail later.

[Step S35]
If the variation of the distance d1 is within the variation amount d-rge, the distance variation monitoring unit 18 determines that the variation of the distance d1 is stopped, and the X-ray irradiation prohibition / permission notifying unit 20 is irradiated with the X-ray irradiation. Notify permission of.

[Step S36]
When the fluctuation of the distance d1 exceeds the range of the fluctuation amount d-rge, the distance fluctuation monitoring unit 18 determines that the fluctuation of the distance d1 is continuing, and the X-ray irradiation prohibition / permission notifying unit 20 is irradiated with the X-ray irradiation. Is prohibited and the measurement of the stop time t is stopped and reset.

[Step S37]
The X-ray irradiation prohibition / permission notifying unit 20 notifies the high voltage generator 2 and the X-ray controller 3 of prohibition or permission of X-ray irradiation. When the high voltage generator 2 receives the X-ray irradiation prohibition notification, the high-voltage generator 2 stops the irradiation of the X-ray pulse from the X-ray tube 1. On the other hand, the high voltage generator 2 continues the irradiation of the X-ray pulse from the X-ray tube 1 while receiving the notification of permission of the X-ray irradiation. In the third embodiment, when step S37 ends, the process returns to step S11, and these steps S11 to S37 are repeated.

  Here, the procedure of the variation determination process for determining whether the variation of the distance d1 is within the range of the variation amount d-rge will be described with reference to FIG.

[Step S341]
When the fluctuation determination process is started, the distance fluctuation monitoring unit 18 updates the stop time t for judging the fluctuation of the distance d1 and starts measuring the stop time t.

[Step S342]
The distance variation monitoring unit 18 updates the maximum value (maximum distance) d1 (max) and the minimum value (minimum distance) d1 (min) of the distance d1 within the stop time t updated in step S341.

[Step S343]
The distance variation monitoring unit 18 determines whether or not the latest distance (current distance) d1 among the distances d1 received from the distance calculation unit 15 is equal to or greater than the maximum distance d1 (max) updated in step S342. To do. The current distance d1 is the maximum distance d1 (max) within the stop time t if the value is equal to or greater than the updated maximum distance d1 (max). On the other hand, the current distance d1 is not the maximum distance d1 (max) within the stop time t unless the value is equal to or larger than the updated maximum distance d1 (max).

[Step S344]
When determining that the current distance d1 is the maximum distance d1 (max) within the stop time t, the distance variation monitoring unit 18 proceeds to step S344 and updates the current distance d1 to the maximum distance d1 (max).

[Step S345]
When the distance variation monitoring unit 18 determines that the current distance d1 is not the maximum distance d1 (max) within the stop time t, the current distance d1 is a value equal to or smaller than the minimum distance d1 (min) updated in step S342. Or not. The current distance d1 is the minimum distance d1 (min) within the stop time t if the value is equal to or smaller than the updated minimum distance d1 (min). On the other hand, the current distance d1 is not the minimum distance d1 (min) within the stop time t unless it is a value equal to or smaller than the updated minimum distance d1 (min).

[Step S346]
When the distance variation monitoring unit 18 determines that the current distance d1 is the minimum distance d1 (min) within the stop time t, the process proceeds to step S346, and the current distance d1 is updated to the minimum distance d1 (min). ..

[Step S347]
The distance fluctuation monitoring unit 18 determines that the difference between the maximum distance d1 (max) and the minimum distance d1 (min) within the stop time t is within the fluctuation amount d-rge (| d1 (max) -d1 (min)). | ≦ d-rge) is determined. If Yes in step S347, the difference between the maximum distance d1 (max) and the minimum distance d1 (min) within the stop time t is within the range of the fluctuation amount d-rge (| d1 (max) -d1 (min) | ≦ d-rge), the distance variation monitoring unit 18 determines that the distance d1 is within the range of the variation amount d-rge, and shifts the processing to step S35 in FIG. 8 (permits X-ray pulse irradiation). ..

  On the other hand, if No in step S347, the distance variation monitoring unit 18 determines that the difference between the maximum distance d1 (max) and the minimum distance d1 (min) within the stop time t exceeds the range of the variation amount d-rge. Since (| d1 (max) -d1 (min) |> d-rge), it is determined that the variation of the distance d1 exceeds the range of the variation amount d-rge, and the process proceeds to step S36 of FIG. 8 (X-ray pulse Irradiation is prohibited).

  Hereinafter, a specific example of the variation determination process described in FIG. 9 will be described with reference to FIG. 10. In this example, it is assumed that the stop time t = 5 and the allowable fluctuation amount d-rge = 7 are preset. The horizontal axis in FIG. 10 is the time axis (tx), and the time tx has the same value as the number of times of detection of the distance d1 detected by the distance measuring unit 6. For example, at time tx = 2, the distance d1 is detected twice by the distance measuring unit 6. Also, the numerical values in the square blocks in the figure respectively indicate the distance d1 at each time, and for example, the numerical value "30" in the block located at the top in the figure indicates the distance d1 at time tx = 1. = 30.

  The distance variation monitoring unit 18 stores and accumulates the distance d1 for each time. For example, when the time tx = 3, the distance variation monitoring unit 18 determines that the distance d1 = 30 when the time tx = 1, the distance d1 = 31 when the time tx = 2, and the distance d1 when the time tx = 3. = 29 is stored.

  The distance variation monitoring unit 18 determines the variation amount of the distance d1 when the elapsed time tx is the same as the stop time t or longer than the stop time t. For example, in this example, since the stop time t = 5, the variation amount of the distance d1 is determined when the time tx ≧ 5. Hereinafter, a specific example of the change of the distance d1 for each elapsed time tx and the process performed by the distance change monitoring unit 18 for each time tx will be described.

[When tx = 1]
The distance variation monitoring unit 18 starts measuring the stop time t at the same time when the irradiation of the X-ray pulse is started. The distance variation monitoring unit 18 updates and stores the distance d1 (at time tx = 1) obtained first after the start of the stop time t as the maximum distance d1 (max) and the minimum distance d1 (min).

[When tx = 2]
When the time tx = 2, the distance variation monitoring unit 18 compares the current distance d1 = 31 with the distance d1 (= 30) stored so far. In this case, since the current distance d1 = 31 is larger than the distance d1 = 30 when the time tx = 1, the current distance d1 = 31 is updated to the maximum distance d1 (max).

[When tx = 3]
The distance variation monitoring unit 18 compares the current distance d1 = 29 with the distance d1 (= 30, 31) when tx = 1 and tx = 2 stored so far. In this case, the current distance d1 = 29 is smaller than the distance d1 up to now, so the current distance d1 is updated to the minimum distance d1 (min).

[When tx = 4]
The distance variation monitoring unit 18 updates the current distance d1 to the maximum distance d1 (max) because the current distance d1 = 31 is the maximum value among the distances d1 stored so far.

  In this way, the distance variation monitoring unit 18 compares the current distance d1 with the distance d1 stored so far, and updates the maximum distance d1 (max) and the minimum distance d1 (min) as needed. In addition, when the time tx = 1 to 4 described above, the time tx <5, which is less than the preset stop time t = 5, the distance variation monitoring unit 18 still determines the variation amount of the distance d1. The determination of No. is not performed and the irradiation of the X-ray pulse is continued to be permitted. The distance variation monitoring unit 18 determines the variation amount of the distance d1 when the time tx ≧ 5 and the number of detected distances d1 (the number of samples) becomes 5 or more samples. The processing when the time tx ≧ 5 is described below.

[When tx = 5]
When the time tx = 5, the distance variation monitoring unit 18 determines whether the current distance d1 = 30 is the maximum value or the minimum value among the distances d1 stored so far. Here, since the current distance d1 = 30 is neither the maximum value nor the minimum value, the maximum distance d1 (max) and the minimum distance d1 (min) are not updated. Then, the distance fluctuation monitoring unit 18 determines that the difference between the maximum distance d1 (max) = 31 (when tx = 2, 4) and the minimum distance d1 (min) = 29 (when tx = 3) is the fluctuation amount d- It is determined whether or not rge = 7 or less. Specifically, the difference between the maximum distance d1 (max) (= 31) and the minimum distance d1 (min) (= 29) is calculated, and the absolute value of the difference is compared with the variation d-rge (= 7). .. Since the difference between the maximum distance d1 (max) and the minimum distance d1 (min) is less than or equal to the fluctuation amount d-rge (| 31-29 | ≦ 7), the distance fluctuation monitoring unit 18 changes the fluctuation amount of the distance d1 by the fluctuation amount d-rge. -It is judged to be within the range of rge.

[When tx = 6]
The distance variation monitoring unit 18 monitors the variation of the distance d1 at the stop time t = 5 by using the five latest samples of the distance d1. Therefore, when tx = 6, the distance variation monitoring unit 18 monitors the variation of the distance d1 using 5 samples at the time tx = 2 to tx = 6. Specifically, it is determined whether the current distance d1 = 40 is the maximum value or the minimum value among the distances d1 stored between tx = 2 and tx = 6. At this time, since the current distance d1 is the maximum value, the distance variation monitoring unit 18 updates the current distance d1 = 40 to the maximum distance d1 (max). Then, the distance variation monitoring unit 18 determines whether or not the difference between the maximum distance d1 (max) = 40 and the minimum distance d1 (min) = 29 (when tx = 3) is the variation amount d-rge = 7 or less. To judge. Since the difference between the maximum distance d1 (max) and the minimum distance d1 (min) exceeds the fluctuation amount d-rge (| 40-29 |> 7), the distance fluctuation monitoring unit 18 changes the fluctuation of the distance d1. It is judged that the amount exceeds the range of d-rge, and the irradiation of the X-ray pulse is prohibited.

[When tx = 7]
When tx = 7, the distance variation monitoring unit 18 monitors the variation of the distance d1 using 5 samples at the time tx = 3 to tx = 7. Specifically, the distance variation monitoring unit 18 determines whether the current distance d1 = 30 is the maximum value or the minimum value among the distances d1 stored during tx = 3 to tx = 7. At this time, since the current distance d1 is neither the maximum value nor the minimum value, the maximum distance d1 (max) and the minimum distance d1 (min) are not updated. Then, the distance variation monitoring unit 18 determines whether or not the difference (40-29) between the maximum distance d1 (max) = 40 and the minimum distance d1 (min) = 29 is less than or equal to the variation amount d-rge = 7. To do. Since 40-29> 7, the distance variation monitoring unit 18 determines that the variation of the distance d1 exceeds the range of the variation amount d-rge, and continues to prohibit the irradiation of the X-ray pulse.

[When tx = 8]
The distance variation monitoring unit 18 monitors the variation of the distance d1 by using 5 samples at the time tx = 4 to tx = 8. At this time, since the sample of tx = 3, which is the minimum distance so far, is not used, the distance variation monitoring unit 18 causes the distance d1 = 30 at the time tx = 5 and 7 at which the distance d1 becomes the smallest within the stop time t. Is updated to the minimum distance d1 (min). Then, the distance variation monitoring unit 18 determines whether or not the difference between the maximum distance d1 (max) = 40 and the minimum distance d1 (min) = 30 is the variation amount d-rge = 7 or less. Since 40-30> 7, the distance variation monitoring unit 18 determines that the variation of the distance d1 exceeds the range of the variation amount d-rge, and continues to prohibit the irradiation of the X-ray pulse.

[When tx = 9, when tx = 10]
Similarly, when tx = 9 and 10, the distance variation monitoring unit 18 determines whether the variation of the distance d1 is within the range of the variation amount d-rge. Since the variation of the distance d1 exceeds the range of the variation amount d-rge at any of tx = 9 and 10, the distance variation monitoring unit 18 continues to prohibit the irradiation of the X-ray pulse.

[When tx = 11]
The distance variation monitoring unit 18 monitors the variation of the distance d1 using 5 samples at the time tx = 7 to tx = 11. At this time, since the sample of tx = 6 which is the maximum distance so far is not used, the distance variation monitoring unit 18 sets the maximum distance d1 = 31 at the time tx = 8 when the distance d1 becomes the largest within the stop time t. The distance is updated to d1 (max). Then, the distance variation monitoring unit 18 determines whether or not the difference between the maximum distance d1 (max) = 31 and the minimum distance d1 (min) = 29 is less than or equal to the variation amount d-rge = 7. Since 31-29 ≦ 7, the distance variation monitoring unit 18 determines that the distance d1 is within the range of the variation amount d-rge, and determines permission of X-ray pulse irradiation.

As described above, in the third embodiment, it is possible to determine whether or not the X-ray pulse irradiation is possible, depending on whether or not the variation of the distance d1 is allowable. For example, when the body movement of the subject 101 exceeds the allowable range within the stop time t, irradiation of the X-ray pulse can be prohibited to prevent invalid exposure. Further, for example, even when a medical staff or a cleaning staff is working in an area where X-rays are irradiated, the variation of the distance d1 exceeds the allowable range, and therefore the irradiation of X-ray pulses is prohibited to prevent invalid exposure. Can be prevented.
<Embodiment 4>
Hereinafter, processing of the X-ray fluoroscopic imaging apparatus 100 according to the fourth embodiment will be described with reference to FIGS. The processing procedure of the fourth embodiment is based on the third embodiment, and the distance variation monitoring unit 18 is the same as the processing procedure of the third embodiment until step S34 of monitoring whether the variation of the distance d1 is within the range of d-rge. Is. The X-ray fluoroscopic apparatus 100 according to the fourth embodiment monitors the fluctuation of the distance d1 and determines whether the fluctuation of the distance d1 is within the allowable fluctuation amount d-rge during the fluctuation stop time t. The pulse rate of the X-ray pulse is controlled accordingly.

  As shown in FIG. 11, the system control unit 14 of the fourth embodiment includes a distance calculation unit 15, a fluoroscopic X-ray condition determination unit 16, an X-ray condition change notification unit 17, a distance variation monitoring unit 18, and an allowable variation. An amount setting unit 21 and a fluctuation stop time setting unit 22 are provided.

[Step S34]
As shown in FIG. 12, in the fourth embodiment, the distance variation monitoring unit 18 determines whether or not the distance d1 is within the allowable variation amount d-rge during the stop time t in the third embodiment. It is determined in the same manner as in step S34. The process of the X-ray fluoroscopic imaging apparatus 100 proceeds to the next step S45 when it is determined that the distance d1 does not change, and proceeds to step S46 when it is determined that the distance d1 continues to change.

[Step S45]
When the fluctuation of the distance d1 is within the allowable fluctuation amount d-rge, the distance fluctuation monitoring unit 18 determines that the fluctuation of the distance d1 is stopped, and the fluctuation of the distance d1 is stopped. The information is notified to the fluoroscopic X-ray condition determining unit 16. When the fluoroscopic X-ray condition determining unit 16 receives the information that the variation of the distance d1 is stopped, the fluoroscopic X-ray condition determining unit 16 determines to maintain the current pulse fluoroscopic rate.

[Step S46]
When the fluctuation of the distance d1 exceeds the allowable fluctuation amount d-rge, the distance fluctuation monitoring unit 18 determines that the fluctuation of the distance d1 is continuing, and the fluctuation of the distance d1 is continuing. Is notified to the fluoroscopic X-ray condition determining unit 16, and the measurement of the stop time t is stopped and reset. When the fluoroscopic X-ray condition determination unit 16 receives the information that the variation of the distance d1 continues from the distance variation monitoring unit 18, the fluoroscopic X-ray condition determination unit 16 determines to change the pulse fluoroscopic rate to a low value.

[Step S47]
The X-ray condition change notifying unit 17 notifies the high voltage generator 2 and the X-ray controller 3 of the maintenance or change of the pulse fluoroscopic rate determined in step S47 or step S48. When the high voltage generator 2 receives the pulse fluoroscopic rate change notification, the high voltage generator 2 changes the pulse fluoroscopic rate to a low value. In the fourth embodiment, when step S47 ends, the process returns to step S11, and these steps S11 to S47 are repeated.

  As described above, in the fourth embodiment, the variation of the distance d1 detected by the distance measuring unit 6 is monitored, and the fluoroscopic pulse rate is set according to whether the variation of the distance d1 is within the allowable range during a predetermined time. Can be changed. For example, when the body movement of the subject 101 exceeds the allowable range, the fluoroscopic pulse rate can be changed to a low value to reduce the invalid exposure of the subject 101.

<Embodiment 5>
Hereinafter, the processing of the X-ray fluoroscopic imaging apparatus 100 according to the fifth embodiment will be described with reference to FIGS. The processing of the fifth embodiment is based on the first embodiment, and is the same as the processing of the first embodiment up to step S22 when the irradiation of the imaging X-ray is started when the imaging switch 24 is pressed. In the X-ray fluoroscopic imaging apparatus 100 according to the fifth embodiment, the variation of the distance d1 is within a permissible variation range d-rge between the start and the end of the X-ray irradiation after the X-ray pulse irradiation. Depending on whether or not it is within the range, processing for determining whether to continue or interrupt the shooting is performed.

  As shown in FIG. 13, the system control unit 14 of the fifth embodiment includes a distance calculation unit 15, a distance variation monitoring unit 18, an allowable variation amount setting unit 21, and imaging control for controlling irradiation or continuation of imaging X-rays. And a section 23.

  The X-ray imaging is started when a doctor or the like presses the imaging switch 24 during irradiation of the X-ray pulse, and ends when the operation of the imaging switch 24 is stopped. When continuously capturing X-ray images, as shown in FIG. 14, when a doctor or the like presses the capturing switch 24, capturing X-rays are continuously emitted at a predetermined timing. The distance variation monitoring unit 18 determines that the distance d1 has greatly changed at the moment when the distance d1 exceeds the allowable variation amount d-rge while the operation switch 24 is operated and is turned on, and the photographing X Prohibit irradiation of rays. After that, the distance variation monitoring unit 18 prohibits the X-ray irradiation even if the photographing switch 24 is pressed. Therefore, in the case shown in FIG. No shooting is performed after shooting.

  Hereinafter, a processing procedure performed by the X-ray fluoroscopic apparatus 100 according to the fifth embodiment will be described.

[Step S22]
As shown in FIG. 15, when the X-ray imaging is started in step S22, the subject 101 is thereby irradiated with the imaging X-ray. At this time, the distance variation monitoring unit 18 records the distances d1 and d2 received by the distance calculation unit 15 and the distance Δd calculated by the distance calculation unit 15. The allowable fluctuation amount setting unit 21 notifies the distance fluctuation monitoring unit 18 of the allowable fluctuation amount d-rge.

[Step S55]
The distance variation monitoring unit 18 monitors whether or not the variation amount of the distance d1 is within the allowable range d-rge during X-ray imaging. The distance variation monitoring unit 18 records the distance d1 (distance d1-rs) at the timing when the imaging switch 24 is pressed by a doctor or the like and X-ray imaging is started.

[Step S56]
When the difference between the distance d1-rs at the start of X-ray photography and the current distance d1 (tx) is within the allowable range d-rge (| d1-rs-d1 (tx) | ≦ d-rge), The distance variation monitoring unit 18 determines that the variation of the distance d1 is within the allowable range. When the difference between the distance d1-rs and the current distance d1 (tx) exceeds the allowable range d-rge, the distance variation monitoring unit 18 determines that the distance d1 has significantly changed during the X-ray imaging. The process of the X-ray fluoroscopic apparatus 100 proceeds to step S57 when it is determined that the variation of the distance d1 is within the allowable range, and proceeds to step S58 when it is determined that the distance d1 has significantly changed.

[Step S57]
The imaging control unit 23 determines whether the X-ray imaging is continued or ended. If the X-ray imaging is continuing, the process of the system control unit 14 returns to step S56.

[Step S58]
The distance variation monitoring unit 18 instructs the imaging control unit 23 to suspend the X-ray imaging when the imaging control unit 23 determines that a large variation occurs during the continuous irradiation of the imaging X-rays. The imaging controller 23 instructs the high voltage generator 2 and the X-ray controller 3 to suspend the X-ray imaging. When the high voltage generator 2 and the X-ray controller 3 receive the instruction to interrupt the continuous X-ray imaging, the X-ray irradiation from the X-ray tube 1 is interrupted.

[Step S59]
When the irradiation of the photographing X-ray is stopped due to the end or interruption of the X-ray photographing, the photographing control unit 23 notifies the distance variation monitoring unit 18 of the timing when the irradiation of the photographing X-ray is stopped. In the fifth embodiment, when the shooting ends in step S59, the process returns to step S11 in FIG.

  As described above, in the fifth embodiment, when the distance d1 exceeds the permissible range d-rge during the period from the start to the end of continuous X-ray imaging, the distance variation monitoring unit 18 makes continuous X-rays. Stop the irradiation of the line. As a result, when the subject 101 makes a large movement, or when the medical staff is working by entering an area where X-rays are irradiated, it is possible to prohibit X-ray imaging and prevent invalid exposure.

  In the fifth embodiment, when the distance d1 exceeds the allowable range d-rge, the distance variation monitoring unit 18 interrupts continuous X-ray irradiation, but the present invention is not limited to this. For example, when the distance d1 exceeds the allowable range d-rge, the X-ray fluoroscopic imaging apparatus 100 notifies the user of a warning, such as the distance variation monitoring unit 18 instructing the display device 13 to display a warning. Good.

<Sixth Embodiment>
Hereinafter, processing of the X-ray fluoroscopic imaging apparatus 100 according to the sixth embodiment will be described with reference to FIGS. 16 and 17. In the sixth embodiment, the X-ray fluoroscopic imaging apparatus 100 uses the distance Δd calculated by the distance calculation unit 15 to pass through the subject 101 according to the inclination (oblique angle θ) of the X-ray tube 1 with respect to the table 8. The actual X-ray transmission distance ΔD is calculated, and the set values of the fluctuation amount d-rge and the stop time t are changed.

  As described in the configuration of the X-ray fluoroscopic imaging apparatus 100, as shown in FIGS. 16A and 16B, the X-ray tube 1 is rotatable with respect to the table 8. As shown in FIG. 16A, when the X-ray pulse is applied to the subject 101 lying on his / her back on the table 8 from directly above (abdominal side) (hereinafter, referred to as vertical imaging), the X-ray from the table 8 is emitted. The distance Δd to the irradiation position and the distance of the X-ray transmitted through the body of the subject 101 match. On the other hand, when the subject 101 is obliquely irradiated with the X-ray pulse as shown in FIG. 16B (hereinafter, referred to as oblique photographing), the distance from the table 8 to the X-ray irradiation position and the penetration through the body. The X-ray transmission distance ΔD is different. Therefore, in the sixth embodiment, the X-ray fluoroscopic imaging apparatus 100 calculates the X-ray transmission distance ΔD that penetrates the subject 101 from the oblique insertion angle θ and the distance Δd, and determines the threshold value (variation amount d-rge) of the fluoroscopic X-ray condition. And stop time t) are changed.

  Hereinafter, a processing procedure performed by the X-ray fluoroscopic apparatus 100 according to the sixth embodiment will be described. The processing procedure of the sixth embodiment is the same as that of the first embodiment up to step S13 in which the distance calculator 15 calculates the distance Δd from the distances d1 to d3. When the process of the sixth embodiment is started, the allowable fluctuation amount setting unit 21 is set to a predetermined fluctuation amount d-rge, and the fluctuation stop time setting unit 22 is set to a predetermined stop time t. ..

[Step S64]
As shown in FIG. 17, in step S64, the distance calculation unit 15 receives the information on the oblique insertion angle θ detected and transmitted by the support mechanism control device 9.

[Step S65]
The distance calculator 15 determines whether the X-ray tube 1 is tilted with respect to the table 8. The process of the X-ray fluoroscopic imaging apparatus 100 proceeds to step S66 during oblique irradiation (θ ≠ 0), and returns to step S11 during vertical imaging (θ = 0).

[Step S66]
At the time of oblique incident irradiation (θ ≠ 0), the distance calculation unit 15 recalculates the distance Δd by correcting the distance d1 and the distance d2 by using the information of the oblique angle θ received by the system control unit 14, and calculates the distance Δd. The actual X-ray transmission distance ΔD that passes through the examiner 101 is calculated.

[Step S67]
The distance calculation unit 15 transmits information on the oblique insertion angle θ to the allowable fluctuation amount setting unit 21 and the fluctuation stop time setting unit 22. The allowable variation amount setting unit 21 changes the setting value (threshold value) of the variation amount d-rge from the received information on the oblique insertion angle θ. Further, the variable stop time setting unit 22 changes the set value (threshold value) of the stop time t. In the sixth embodiment, when step S67 ends, the process returns to step S11, and these steps S11 to S67 are repeated.

  As described above, in the sixth embodiment, the set values of the variation amount d-rge and the stop time t can be changed according to the oblique incidence angle θ of the X-ray pulse. As a result, the processing of the first to fifth embodiments can be performed using the variation amount d-rge and the stop time t that are changed according to the oblique insertion angle θ. Therefore, even if the X-ray tube 1 is tilted with respect to the table 8, it is possible to determine an appropriate fluoroscopic X-ray irradiation condition and reduce the exposure dose of the subject.

  Since the X-rays are radially emitted from the X-ray tube 1, the distance of transmission through the subject 101 differs depending on the radiation angle. Therefore, the distance of the X-ray transmitted through the subject 101 has a value different from the distance Δd depending on the radiation angle. Therefore, the distance calculation unit 15 is not limited to the case where the X-ray tube 1 is inclined with respect to the table 8, and the distance Δd is calculated using the radiation angle of the X-rays emitted from the X-ray tube 1 toward the subject 101. May be corrected to change the variation amount d-rge and the stop time t.

<Embodiment 7>
Hereinafter, the processing of the X-ray fluoroscopic imaging apparatus 100 according to the seventh embodiment will be described with reference to FIG. The seventh embodiment uses the distance Δd calculated by the distance calculation unit 15 to set a variation amount d-rge and a set value (threshold value) of the stop time t according to the portion when the procedure or the inspection portion is changed. Modifications are different from the other embodiments.

  As described in the configuration of the X-ray fluoroscopic imaging apparatus 100, the image processing apparatus 12 stores the combination of the examination site and the procedure. When at least one of the examination site and the procedure stored in the image processing apparatus 12 is changed by a doctor or the like operating an operation unit (not shown) connected to the system control unit 14, the system control unit 14 The threshold value of the fluoroscopic X-ray condition (the set value of the variation amount d-rge and the stop time t) is changed according to the changed examination site or procedure.

  Hereinafter, a processing procedure performed by the X-ray fluoroscopic imaging apparatus 100 according to the seventh embodiment will be described. The processing procedure of the seventh embodiment is the same as that of the first embodiment up to step S13 in which the distance calculation unit 15 calculates the distance Δd from the distances d1 to d3. When the process of the seventh embodiment is started, the allowable fluctuation amount setting unit 21 is set to a predetermined fluctuation amount d-rge, and the fluctuation stop time setting unit 22 is set to a predetermined stop time t. ..

[Step S74]
When a doctor or the like operates an operation unit (not shown), at least one of the examination site and the procedure stored in the image processing apparatus 12 is changed. When the image processing apparatus 12 recognizes that at least one of the examination site and the procedure has been changed, the image processing apparatus 12 notifies the distance calculation unit 15 of the information about the changed examination site or the procedure.

[Step S75]
The distance calculation unit 15 notifies the allowable variation amount setting unit 21 and the variation stop time setting unit 22 of the changed information on the changed inspection site or procedure. The permissible fluctuation amount setting unit 21 changes the set value (threshold value) of the fluctuation amount d-rge from the received information on the inspection site or the procedure information. Further, the variable stop time setting unit 22 changes the set value (threshold value) of the stop time t based on the received information on the inspection site or the procedure information. In the seventh embodiment, when step S75 ends, the process returns to step S11, and these steps S11 to S75 are repeated.

  As described above, in the seventh embodiment, the set values of the variation amount d-rge and the stop time t can be changed according to the inspection site or the procedure. Thereby, the processing of Embodiments 1 to 5 can be performed using the variation amount d-rge and the stop time t that are changed according to the inspection site or the procedure. Therefore, it is possible to determine an appropriate irradiation condition of the fluoroscopic X-ray according to the examination site or the procedure and reduce the exposure dose of the subject.

  The internal configuration of the system control unit 14 may be a combination of the units described in the first to seventh embodiments, and the X-ray fluoroscopic imaging apparatus 100 is one of the processes in the first to seventh embodiments described above. One process may be carried out, or a plurality of processes may be carried out in combination.

  DESCRIPTION OF SYMBOLS 1 ... X-ray irradiation part (X-ray tube), 2 ... High voltage generator, 3 ... X-ray control device, 4 ... X-ray movable diaphragm, 5 ... X-ray movable diaphragm control device, 6 ... Distance measuring part, 7 ... Distance measuring unit control device, 8 ... Table, 9 ... Support mechanism control device, 10 ... X-ray detector, 11 ... X-ray detector control device, 12 ... Image processing device, 13 ... Display device, 14 ... System control unit, 15 ... Distance calculation unit, 16 ... Perspective X-ray condition determination unit, 17 ... X-ray condition change notification unit, 18 ... Distance variation monitoring unit, 19 ... X-ray irradiation prohibition / permission distance setting unit, 20 ... X-ray irradiation prohibition permission Notification unit, 21 ... Allowable fluctuation amount setting unit, 22 ... Fluctuation stop time setting unit, 23 ... Imaging control unit, 100 ... X-ray fluoroscopic imaging apparatus, 101 ... Subject

Claims (11)

An X-ray irradiation unit that repeatedly irradiates the subject with X-ray pulses at a predetermined pulse rate;
An X-ray detector for detecting X-rays transmitted through the subject;
A distance measuring unit that is provided in the vicinity of the X-ray irradiation unit and measures a first distance to the body surface of the subject;
An X-ray fluoroscopic imaging apparatus comprising: a system control unit that determines an irradiation condition of an X-ray pulse that is repeatedly irradiated according to at least the first distance. The X according to claim 1, wherein the system control unit determines at least one of the pulse rate of the X-ray pulse and whether or not to irradiate the X-ray pulse according to the first distance. Fluoroscopic imaging device. A support mechanism that supports the X-ray irradiation unit and a table on which a subject is placed, and moves the positions of the X-ray irradiation unit and the table;
A support mechanism control unit that controls the operation of the support mechanism to calculate a second distance from the X-ray irradiation unit to the table surface;
A distance measuring unit control unit that calculates a third distance from the X-ray irradiation unit to the distance measuring unit;
A body thickness calculator that calculates a fourth distance between the table surface and the body surface from the first distance, the second distance, and the third distance,
The fluoroscopy apparatus according to claim 1, wherein the system control unit determines the irradiation condition by using the fourth distance. The X-ray X-ray condition determining unit that determines the irradiation intensity of X-rays for X-ray imaging from the irradiation conditions determined by the system control unit is further provided. Fluoroscopic imaging device. The system control unit,
A distance variation monitoring unit that monitors the variation of the first distance,
An irradiation prohibition / permission distance setting unit that sets a prohibition distance that becomes a threshold value that prohibits the irradiation of the X-ray pulse or an allowable distance that becomes a threshold value that allows the irradiation of the X-ray pulse,
An irradiation prohibition / permission notifying unit which notifies the photographing X-ray condition determining unit of prohibition or permission of irradiation of the X-ray pulse,
5. The distance variation monitoring unit compares the prohibited distance or the permitted distance with the changed first distance to determine whether to prohibit or permit the irradiation of the X-ray pulse. The X-ray fluoroscopic imaging apparatus described in 1. The system control unit,
A distance variation monitoring unit that monitors the variation of the first distance,
A distance variation recording unit that records the variation of the first distance,
An allowable fluctuation amount setting unit that sets an allowable fluctuation amount of the first distance;
A variable stop time setting unit that sets a stop time at which the subject should be stopped,
When the distance variation monitoring unit determines that the variation amount of the first distance exceeds the allowable variation amount within the stop time, the X-ray irradiation unit stops the irradiation of the X-ray pulse. The X-ray fluoroscopic imaging apparatus according to claim 1.   When the distance variation monitoring unit determines that the difference between the maximum value of the first distance and the minimum value of the first distance exceeds the allowable variation amount within the stop time, the X-ray irradiation is performed. The X-ray fluoroscopic imaging apparatus according to claim 6, wherein the unit stops irradiation of the X-ray pulse. The system control unit,
A distance variation monitoring unit that monitors the variation of the first distance,
A distance variation recording unit that records the variation of the first distance,
A pulse fluoroscopic rate control unit for controlling the pulse rate of the X-ray pulse,
The X-ray fluoroscopic imaging apparatus according to claim 1, wherein the pulse fluoroscopic rate control unit changes the pulse rate according to a variation amount of the first distance. The system control unit,
A distance variation monitoring unit that monitors the variation of the first distance,
A distance variation recording unit that records the variation of the first distance,
An imaging control unit that controls the irradiation of imaging X-rays is provided,
The distance variation monitoring unit allows the first distance to have an allowable variation amount during continuous irradiation of imaging X-rays in order to perform continuous X-ray imaging by the X-ray irradiation unit. The X-ray fluoroscopic imaging apparatus according to claim 1, wherein the imaging control unit is instructed to interrupt the continuous irradiation of the imaging X-rays when the number exceeds X. The system control unit,
A distance variation monitoring unit that monitors the variation of the first distance,
An allowable fluctuation amount setting unit that sets an allowable fluctuation amount of the first distance;
A variable stop time setting unit that sets a stop time at which the subject should be stopped,
When the X-ray pulse is obliquely applied to the table surface on which the subject is placed, the system control unit sets the allowable fluctuation amount set by the allowable fluctuation amount setting unit, The X-ray fluoroscopic imaging apparatus according to claim 1, wherein at least one of the stop times set by the variable stop time setting unit is changed. The system control unit,
A distance variation monitoring unit that monitors the variation of the first distance,
An allowable fluctuation amount setting unit that sets an allowable fluctuation amount of the first distance;
A variable stop time setting unit that sets the stop time that the subject should have stopped,
An examination procedure performed on the subject or an examination procedure part recognition unit for recognizing the examination part of the subject irradiated with the X-ray pulse;
When the inspection technique part recognition unit recognizes the inspection technique or the change of the inspection region, the system control unit causes the allowable fluctuation amount set by the allowable fluctuation amount setting unit and the fluctuation stop time setting unit. The X-ray fluoroscopic imaging apparatus according to claim 1, wherein at least one of the stop times set by is changed according to the inspection procedure or the inspection site.

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