JP2006014935A - X-ray diagnostic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diagnostic apparatus in which a movable part moves quickly while avoiding a collision with an obstacle.
In an X-ray fluoroscopic apparatus, a distance Lm between a detector 3 for detecting X-rays, a subject M, an operator, and other obstacles is measured by a capacitive sensor 7 and a sensor circuit 8. To do. Here, the effective measurement range (range) of the sensor circuit 8 is changed based on the moving speed v of the detector 3. Therefore, the measured separation distance Lm has good accuracy. Based on the separation distance Lm and the moving speed v of the detector 3, the drive control unit 11 operates the drive unit 5 so as to brake the detector 3. Therefore, since the accuracy of the measured separation distance Lm is good, the collision between the detector 3 and the obstacle can be avoided with certainty. Therefore, the detector 3 is not unnecessarily braked when moving at a low speed, and is not erroneously braked due to a measurement error or the like.
[Selection] Figure 1

Description

  The present invention relates to an X-ray diagnostic apparatus that performs X-ray imaging, such as an X-ray fluoroscopic apparatus, and more particularly to a technique for controlling a movable part so as not to collide with an obstacle.

  Conventionally, as this type of apparatus, there are an X-ray fluoroscopic apparatus and an X-ray tomographic apparatus. Such an X-ray diagnostic apparatus often has a movable part in order to perform X-ray imaging from an arbitrary direction or to allow a subject to easily get on and off the top board.

  Examples of the movable unit include an X-ray tube that irradiates X-rays, an X-ray detector such as an image intensifier that detects X-rays and a flat panel display, and a top plate on which a subject is placed.

The movable portion is driven and controlled so that the movable portion does not come into contact with the subject, the operator, or other obstacles. Specifically, a distance sensor that measures the distance (separation distance) between the obstacle and the movable part in a non-contact manner is provided, and the separation distance is constantly monitored. When a sufficient separation distance cannot be ensured, braking control such as deceleration and stop of the movable part is performed to prevent the movable part from colliding with the subject or the like. Here, a capacitance type is exemplified as the distance sensor (see, for example, Patent Document 1).
JP 2001-208504 A

  However, the conventional example having such a configuration has the following problems.

  In recent years, the operation speed of the movable part has been increased. Along with this, the speed range of the movable part is also widened.

  The distance necessary for avoiding the collision between the movable part and the obstacle becomes longer as the movable part becomes higher in speed, and it is necessary to start the braking control earlier. Therefore, if it is assumed that the movable part is always moving at the maximum speed and the braking control is performed, the collision can be avoided regardless of the moving speed.

  For this reason, when the movable part moves at a low speed, the movable part is braked such as decelerating or stopping more than necessary. An X-ray diagnostic apparatus having such a behavior is difficult for an operator to operate.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an X-ray diagnostic apparatus in which the movable part moves quickly while the collision of the movable part with the obstacle is avoided. .

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

  That is, the invention described in claim 1 is an X-ray diagnostic apparatus that performs X-ray imaging by irradiating a subject with X-rays, and includes an X-ray detection unit that detects the irradiated X-rays, and an X-ray detection unit. Driving means for driving, control means for controlling the movement of the X-ray detection means by operating the driving means, distance measuring means for measuring the distance between the X-ray detection means and the obstacle, and movement of the X-ray detection means Change means for changing the effective measurement range of the distance measurement means based on the speed, and the control means is an X-ray detection means based on the separation distance measured by the distance measurement means and the moving speed of the X-ray detection means. Is controlled to brake.

  [Operation / Effect] According to the invention described in claim 1, the effective measurement range of the distance measuring means is changed based on the moving speed of the X-ray detecting means. Therefore, the separation distance between the moving X-ray detection means and the subject, the operator, and other obstacles can be accurately measured. Based on the measured separation distance and the moving speed of the X-ray detection means, the X-ray detection means is controlled to be braked, such as decelerating or stopping. Therefore, compared to the case where the X-ray detection unit is braked based only on the separation distance, the X-ray detection unit is not unnecessarily braked when moving at a low speed. Moreover, since the accuracy of the measured separation distance is good, the collision between the X-ray detection means and the obstacle can be avoided with certainty, and the X-ray detection means is not erroneously braked due to a measurement error or the like. .

  According to a second aspect of the present invention, in the X-ray diagnostic apparatus according to the first aspect, the control unit has a short separation distance measured compared to a safety distance according to the moving speed of the X-ray detection unit. At this time, the X-ray detection means is controlled to be braked.

  [Operation / Effect] According to the invention described in claim 2, it is possible to clearly determine whether or not the separation distance is secured by comparing with the safe speed based on the moving speed of the X-ray detection means. Therefore, it is possible to reliably prevent the X-ray detection means from colliding with the obstacle.

  This specification also discloses an invention relating to the following X-ray diagnostic apparatus.

  (1) In an X-ray diagnostic apparatus that performs X-ray imaging by irradiating a subject with X-rays, a driving unit that drives a movable unit, a control unit that operates the driving unit to control movement of the movable unit, and a movable unit Distance measuring means for measuring the separation distance between the part and the obstacle, and the control means changes the effective measurement range of the distance measuring means based on the moving speed of the movable part, and the moving speed of the movable part An X-ray diagnostic apparatus, wherein the movable part is controlled to be braked on the basis of the distance measured by the distance measuring means.

  In many cases, the top plate on which the subject is placed, the X-ray irradiation means for irradiating X-rays, the X-ray detection means for detecting X-rays transmitted through the subject, and the like are movably supported and become movable parts. The movable part may always collide with the subject, the operator, and other obstacles. Therefore, according to the invention described in (1), it is possible to reliably and accurately avoid the collision of these movable parts with an obstacle, and to brake the movable parts unnecessarily or accidentally. There is no.

  (2) In an X-ray diagnostic apparatus that performs X-ray imaging by irradiating a subject with X-rays, an X-ray irradiation unit that irradiates X-rays, a driving unit that drives the X-ray irradiation unit, and a driving unit are operated. Control means for controlling the movement of the X-ray irradiation means and distance measurement means for measuring the separation distance between the X-ray irradiation means and the obstacle, the control means being based on the moving speed of the X-ray detection means. The effective measurement range of the distance measuring means is changed, and the X-ray detecting means is controlled to be braked based on the moving speed of the X-ray detecting means and the separation distance measured by the distance measuring means. X-ray diagnostic equipment.

  According to the invention described in the above (2), the collision between the X-ray irradiation means and the obstacle can be surely and accurately avoided, and the movable part is not braked unnecessarily or accidentally. .

  According to the X-ray diagnostic apparatus of the present invention, the effective measurement range (range) of the distance measuring unit is changed based on the moving speed of the X-ray detecting unit. The separation distance can be accurately measured. Since the X-ray detection means is controlled to be braked based on the separation distance and the moving speed of the X-ray detection means, X-ray detection is performed as compared with the case where the X-ray detection means is braked based only on the separation distance. It is not unnecessarily braked when the means is moving at low speed. Moreover, since the accuracy of the measured separation distance is good, the collision between the X-ray detection means and the obstacle can be avoided with certainty, and the X-ray detection means is not erroneously braked due to a measurement error or the like. . Therefore, the movable part can move quickly while avoiding the collision of the movable part with the obstacle. In addition, the operability of the X-ray diagnostic apparatus is improved.

  Embodiment 1 of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram illustrating a schematic configuration of the X-ray fluoroscopic apparatus according to the embodiment.

  The X-ray fluoroscopic apparatus of the embodiment includes a top plate 1 on which the subject M is placed, an X-ray tube 2 that irradiates the subject M with X-rays, and a detector 3 that detects X-rays that pass through the subject M. A C-shaped arm 4 that holds the X-ray tube 2 and the detector 3, and a drive unit 5 that drives the C-shaped arm 4. In addition to this, the X-ray fluoroscopic apparatus includes a capacitive sensor 7 that detects a change in the electromagnetic field, and a sensor circuit 8 that measures a separation distance Lm between the detector 3 and the obstacle from the detected signal. A range changing unit 9 that changes the effective measurement range (range) of the sensor circuit 8, a drive control unit 11 that controls the movement of the detector 3 by operating the drive unit 5, and an operation command for the X-ray fluoroscope And an input unit 17 for inputting. Here, the obstacle is a general term for the subject M, the operator, and other obstacles. The X-ray fluoroscopic apparatus corresponds to the X-ray diagnostic apparatus according to the present invention.

  The X-ray tube 2 and the detector 3 are held by the C-shaped arm 4 so as to face each other with the subject M interposed therebetween. The C-shaped arm 4 is rotatably supported by the drive unit 5. The drive unit 5 rotates the C-shaped arm 4 based on the drive control unit 11. The C-shaped arm 4 is driven to rotate about a horizontal axis that faces the longitudinal direction of the top plate 1, and the C-shaped arm 4 is rotated about the center of the arc formed by the C-shaped arm 4. Rotating drive. Thereby, the X-ray tube 2 and the detector 3 rotate together with the C-shaped arm 4. The drive unit 5 corresponds to the drive means in this invention.

  When the X-ray tube 2 irradiates the subject M with X-rays, the X-rays transmitted through the subject M reach the detector 3. By detecting this X-ray, the detector 3 can obtain a fluoroscopic image of the subject M. The detector 3 is exemplified by an image intensifier or a flat panel display type detector. The X-ray tube 2 and the detector 3 correspond to the X-ray irradiation means and the X-ray detection means in this invention, respectively.

  The detector 3 is provided with a capacitance type sensor 7. A sensor circuit 8 is electrically connected to the capacitance type sensor 7. FIG. 2 is a schematic diagram showing a schematic configuration of the capacitance type sensor 7 and the sensor circuit 8.

  The capacitive sensor 7 includes a transmission electrode 21 and a reception electrode 22 that are arranged to face each other, and the transmission electrode 21 and the reception electrode 22 are installed on the side wall of the detector 3.

  The sensor circuit 8 is electrically connected to the transmission electrode 21 and the reception electrode 22, respectively.

  A predetermined input voltage Vi is applied to the transmission electrode 21 from the power supply unit 23 to generate a constant electromagnetic field around the detector 3. The generated electromagnetic field is weakened as an obstacle approaches the detector 3. Therefore, as the separation distance Lm between the detector 3 and the obstacle decreases, the output voltage Vo acquired by the receiving electrode 22 also decreases. The comparison amplifier circuit 25 amplifies the difference between the predetermined input voltage Vi and the output voltage Vo corresponding to the separation distance Lm, and detects the detection signal Vd. Therefore, the detection signal Vd increases as the separation distance Lm decreases. The separation distance Lm is measured based on the magnitude of the detection signal Vd.

  As described above, the separation distance Lm between the detector 3 and the obstacle is measured in a non-contact manner by the capacitive sensor 7 and the sensor circuit 8. The capacitive sensor 7 and the sensor circuit 8 correspond to the distance measuring means in this invention.

  Further, the range changing unit 9 adjusts the amplification factor of the comparison amplifier circuit 25. Thereby, the effective measurement range (range) of the separation distance Lm by the sensor circuit 8 and the capacitive sensor 7 can be changed.

  An example of changing the effective measurement range (range) will be described with reference to FIG. FIG. 3 is a diagram schematically showing the relationship between the separation distance Lm and the detection signal Vd when the amplification factor is changed. When the amplification factor is relatively small, the characteristic shown by the curve G1 is obtained. When the amplification factor is increased, the characteristic shown by the curve G2 is obtained.

  Both the curve G1 and the curve G2 output a detection signal Vd corresponding to the separation distance Lm. However, the range in which the separation distance Lm can be accurately measured is different. As shown in FIG. 2, according to the curve G1, a relatively short separation distance Lm within the range R1 can be accurately measured. On the other hand, according to the curve G2, the separation distance Lm within the range R2 can be accurately measured.

  Thus, by adjusting the amplification factor of the comparison amplification unit 25, the range of the separation distance Lm that can be accurately measured, that is, the effective measurement range (range) can be changed. The range changing unit 9 corresponds to changing means in the present invention.

  The input unit 17 is operated when the operator operates the X-ray fluoroscope, and various operation commands are input thereto. The operation command includes “X-ray irradiation” and “movement of the detector 3”.

  In addition to being connected to the drive unit 5 that is the operation target, the drive control unit 11 is connected to the input unit 17 and the sensor circuit 8. From the input unit 17, an operator's driving command is sent. The normal operation unit 15 of the drive control unit 11 controls the movement of the detector 3 by operating the drive unit 5 based on the operation command from the input unit 17. Hereinafter, the control by the normal operation unit 15 is particularly referred to as “normal control”.

  On the other hand, the drive control unit 11 is given a separation distance Lm between the detector 3 and the obstacle from the sensor circuit 8. The braking determination unit 13 determines whether to brake the detector 3 based on the separation distance Lm and the moving speed v of the detector 3. When it is determined that braking is to be performed, the operation of the drive unit 5 is switched from the normal operation unit 15 to the braking operation unit 14. The braking operation unit 14 operates the driving unit 5 so as to brake the moving speed v of the detector 3. Here, braking means decelerating or stopping the moving speed v of the detector 3. Hereinafter, the control by the braking operation unit 14 is particularly referred to as “braking control”. The drive control unit 11 corresponds to the control means in this invention.

  Hereinafter, the drive control unit 11 will be described in detail with reference to FIG. FIG. 4 is a flowchart showing a process flow until braking control is started during normal control.

  First, it is assumed that the X-ray fluoroscopic apparatus is operated by normal control based on an operation command from the input unit 17 by the operator.

<Step S <b>1> The braking determination unit 13 acquires the movement speed v. The braking determination unit 13 acquires the movement speed v of the detector 3. Here, the moving speed v of the detector 3 may be actually measured and acquired, but may be calculated and acquired from the operation amount of the drive unit 5 by the normal operation unit 15.

<Step S2> Obtaining the Safety Distance Ls The braking determination unit 13 determines the minimum distance (hereinafter referred to as “safety distance”) Ls that can avoid the detector 3 from colliding with an obstacle safely. It calculates | requires based on the moving speed v of the detector 3. FIG. In other words, the safety distance Ls continuously changes according to the moving speed v of the detector 3.

  FIG. 5 illustrates how to adopt the safety distance Ls. For example, the safety distance Ls may be changed so as to be proportional to the moving speed v like a straight line with a reference symbol P1. Further, the safety distance Ls may be changed in a curved manner according to the moving speed v, as in the curve denoted by reference symbol P2. Alternatively, as indicated by reference numeral P3, the safety distance Ls may be changed stepwise.

  Therefore, a table in which the moving speed v of the detector 3 and the corresponding safe distance Ls are associated with each other is stored in advance in a storage unit (not shown), and the safe distance Ls is read from the storage unit. It may be configured. Alternatively, the safe distance Ls may be calculated by substituting the moving speed v of the detector 3 into the relational expression between the moving speed v of the detector 3 and the safe distance Ls.

<Step S3> The range changing unit 9 acquires the moving speed v. The range changing unit 9 acquires the moving speed v of the detector 3. Here, the moving speed v of the detector 3 may be actually measured and acquired, but may be acquired indirectly from the braking determination unit 13.

<Step S4> Changing the Range The range changing unit 9 adjusts the amplification factor of the comparison amplifier circuit 25 of the sensor circuit 8 based on the moving speed v. As a result, the effective measurement range (range) of the separation distance Lm between the sensor circuit 8 and the capacitive sensor 7 is changed.

  In the present embodiment, it is important whether the separation distance Lm can secure the safety distance Ls. Therefore, the safety distance Ls corresponding to the moving speed v is changed so that it is at least included in the effective measurement range (range).

<Step S5> Obtaining the Separation Distance Lm The sensor circuit 8 detects the detection signal Vd from the input voltage Vi and the output voltage Vo of the capacitive sensor 7. The braking determination unit 13 acquires the separation distance Lm based on the detection signal Vd.

<Step S6> Does the separation distance Lm secure the safety distance Ls?
The braking determination unit 13 compares the measured separation distance Lm with the determined safety distance Ls. Here, if it can be determined that the separation distance Lm is greater than or equal to the safety distance Ls, braking is not necessary. In this case, the operation of the X-ray fluoroscopic apparatus under normal control is continued and a series of operations are repeated again from step S1.

  On the other hand, when the separation distance Lm is less than the safety distance Ls, it is necessary to brake, and the process proceeds to step S7.

<Step S7> Starting Braking Control The braking determination unit 13 switches the operation of the driving unit 5 from the normal operation unit 15 to the braking operation unit 14. As a result, the operation command from the input unit 17 is canceled and braking control is started so as to brake the detector 3.

  When the braking control is started, the detector 3 decelerates or stops to avoid a collision with an obstacle.

  Thus, according to the X-ray fluoroscopic apparatus according to the present embodiment, the range changing unit 9 changes the effective measurement range (range) based on the moving speed v of the detector 3. Thereby, the separation distance Lm near the safety distance Ls can be accurately measured. Therefore, the determination to start the braking control is also accurate. Therefore, the detector 3 can reliably avoid the collision with the obstacle, and the braking control is not started due to the measurement error of the separation distance Lm.

  Further, since the safe distance Ls is obtained based on the moving speed v of the detector 3, it is possible to make a determination to start the braking control more accurately than in the case where the safe distance is uniformly set. Therefore, the detector 3 can reliably avoid an obstacle and a collision, and braking control is not started unnecessarily, particularly when the detector 3 is moving at a low speed.

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

  (1) In the above-described embodiment, the capacitive sensor 7 is installed in the detector 3, but the configuration is not limited thereto. In other words, the capacitive sensor 7 may be installed in any movable part of the X-ray fluoroscopic apparatus. Thereby, it can avoid colliding with a movable part and an obstruction. For example, the capacitive sensor 7 may be installed in the X-ray tube 2 so as to measure the separation distance Lm between the X-ray tube 2 and the obstacle. Further, in the case where the top plate 1 is moved up and down to become a movable part, the capacitive sensor 7 is installed on the top plate 1 so as to measure the separation distance Lm between the top plate 1 and the obstacle. You may comprise.

  (2) In the above-described embodiment, the capacitive sensor 7 is used as a distance sensor. However, the distance sensor is not limited to the capacitive sensor as long as the distance can be measured without contact. For example, an ultrasonic sensor may be used. Thereby, restrictions, such as a material of a detection target object, can be decreased.

  (3) In the above-described embodiment, the C-shaped arm 4 is provided. However, the configuration is not limited thereto. If the detector 3 is configured to move, it is not necessary to provide the C-shaped arm 4. In addition, the detector 3 and the X-ray tube 2 are configured to move together, but may be configured to move individually.

  (4) The X-ray diagnostic apparatus according to the present invention is not limited to the X-ray fluoroscopic apparatus according to the embodiment but may be an X-ray tomography apparatus.

It is a block diagram which shows schematic structure of the X-ray fluoroscope which concerns on an Example. 3 is a schematic diagram showing a schematic configuration of a capacitance type sensor 7 and a sensor circuit 8. FIG. It is a figure which shows typically the relationship between the separation distance Lm and the detection signal Vd. It is a flowchart which shows the flow of a process until braking control starts in normal control. It is a figure which shows typically the relationship between the moving speed v of the detector 3, and the safe distance Ls.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Top plate 2 ... X-ray tube 3 ... Detector 4 ... C-shaped arm 5 ... Drive part 7 ... Capacitance type sensor 8 ... Sensor circuit 9 ... Range change part 11 ... Drive control part 13 ... Braking judgment part 14 ... Brake operation part 15 ... Normal operation part M ... Subject Lm ... Distance Ls ... Safe distance v ... Movement speed

Claims (2)

  In an X-ray diagnostic apparatus that performs X-ray imaging by irradiating a subject with X-rays, an X-ray detection unit that detects irradiated X-rays, a drive unit that drives the X-ray detection unit, and a drive unit that operates The control means for controlling the movement of the X-ray detection means, the distance measurement means for measuring the distance between the X-ray detection means and the obstacle, and the effective measurement range of the distance measurement means based on the moving speed of the X-ray detection means And the control means controls the X-ray detection means to be braked based on the separation distance measured by the distance measurement means and the moving speed of the X-ray detection means. X-ray diagnostic equipment. The X-ray diagnostic apparatus according to claim 1, wherein the control unit brakes the X-ray detection unit when the measured separation distance is shorter than a safety distance corresponding to the moving speed of the X-ray detection unit. An X-ray diagnostic apparatus characterized by controlling.

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