JP2021049069A - X-ray photographing apparatus - Google Patents

Abstract

To provide an X-ray photographing apparatus that allows a power assist operation with improved responsiveness to be executed to an operation of an operator.SOLUTION: An X-ray photographing apparatus 100 includes: a movable body 3 for supporting at least one of an X-ray tube 1 and an X-ray detection part 2 movably; a drive unit 4 for moving the movable body 3; a sensor 5 for detecting force including operation force F for moving the movable body 3 by an operator; a correction circuit unit 6 for executing individual difference correction H1, which is the correction according to individual differences of the sensor 5, for a detection signal S1 output by the sensor 5 in a hardware manner; and a control unit 7 provided separate from the correction circuit unit 6 for executing posture correction H2, which is the correction according to a change in the posture of the movable body 3, for a correction signal S2, which is the detection signal S1 subjected to the correction by the correction circuit unit 6, in a software manner, and controlling a power assist operation of the drive unit 4.SELECTED DRAWING: Figure 1

Description

The present invention relates to an X-ray imaging apparatus.

Conventionally, an X-ray imaging device that performs a power assist operation when manually moving an X-ray tube is known. (For example, Patent Document 1).

Patent Document 1 describes an X-ray tube that irradiates X-rays, an X-ray receiver, a measuring unit that measures a force for manually moving the X-ray tube, and a driving unit that moves the X-ray tube. An X-ray apparatus including a control unit that controls a drive unit is disclosed. In the X-ray imaging apparatus described in Patent Document 1, the control unit controls the drive unit based on the manual force measured by the measurement unit to move the X-ray tube in the direction desired by the user. It is configured to perform operations.

U.S. Pat. No. 10,206,641

Here, although not described in Patent Document 1, the direction of the measuring unit arranged in the X-ray imaging apparatus may be changed by changing the posture of the X-ray imaging apparatus. That is, even when the measuring unit is made to measure the force from the same direction, the direction of the signal output as a result of the measurement by the measuring unit may be different due to the change in the posture of the device. In this case, the direction of the assist force in the power assist operation changes. Therefore, it is necessary to control the operation of the drive unit after correcting the information output from the measurement unit so that the direction of the assist force does not change even if the attitude of the device is changed based on the attitude of the X-ray imaging device. There is. Further, although not described in Patent Document 1, the measuring unit for measuring the force for manually moving the X-ray tube has individual differences in the detected values. Therefore, it is considered necessary to correct individual differences in the measuring unit (sensor). That is, although not described in Patent Document 1, in the conventional X-ray imaging apparatus, the control unit corrects the signal output by the measurement unit based on the posture of the X-ray imaging apparatus and the measurement unit. It is considered that the power assist operation of the drive unit is controlled so as to assist the force for manually moving the X-ray tube after performing the correction based on the individual difference. In the specification of the present application, "individual difference" is described as meaning that there is a difference in the signal detected when the same force is applied to each of a plurality of measuring units (sensors). ..

However, in the above-mentioned conventional X-ray imaging apparatus, the signal measured by the measuring unit is corrected based on the posture of the X-ray imaging apparatus, the correction based on the individual difference of the measuring unit (sensor), and the X-ray tube. Since the power assist operation of the drive unit that assists the force for manual movement and the power assist operation of the drive unit are combined and controlled by the control unit in terms of software, it is considered that the arithmetic processing of the control unit is burdensome. Therefore, it takes time to control the operation of the power assist (the operation of the drive unit starts), and it is considered that the drive unit performs an operation with a delay with respect to the user's operation. In other words, the above-mentioned conventional X-ray imaging apparatus has a problem that a power assist operation having low responsiveness (uncomfortable feeling) is performed in response to an operation of a user (operator).

The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to be able to perform a power assist operation with improved responsiveness to an operation of an operator. It is to provide an X-ray imaging apparatus.

In order to achieve the above object, the X-ray imaging apparatus according to one aspect of the present invention includes an X-ray tube that irradiates a subject with X-rays and an X-ray detection unit that detects X-rays emitted from the X-ray tube. An X-ray imaging device that performs a power assist operation when at least one of the above is manually moved by an operator, and a moving body that movably supports at least one of an X-ray tube and an X-ray detection unit. The drive unit that moves the moving body, the sensor that detects the force including the operating force for moving the moving body by the operator, and the detection signal output by the sensor are corrected according to the individual difference of the sensor. The correction circuit unit that performs individual difference correction in hardware and the correction circuit unit are provided separately, and respond to changes in the posture of the moving body with respect to the correction signal that is the detection signal corrected by the correction circuit unit. It is provided with a control unit that controls the power assist operation of the drive unit while performing attitude correction which is correction by software. In the specification of the present application, "performing in terms of hardware" means that a fixed circuit for performing arithmetic processing is prepared in advance and processing is performed on an input signal. Further, "performing by software" means performing processing on an input signal according to a program instructing what kind of processing is to be performed when performing arithmetic processing.

In the X-ray imaging apparatus according to one aspect of the present invention, as described above, the correction circuit unit that hardware-wise corrects the detection signal output by the sensor according to the individual difference of the sensor. To be equipped. Then, the X-ray imaging apparatus is provided separately from the correction circuit unit, and the correction signal, which is the detection signal corrected by the correction circuit unit, is corrected according to the change in the posture of the moving body. It is provided with a control unit that controls the power assist operation of the drive unit while performing software. As a result, the arithmetic processing for performing software-like correction according to the individual difference of the sensor by the control unit becomes unnecessary. Therefore, the processing power of the control unit can be devoted to the arithmetic processing of the attitude correction and the control of the power assist operation. As a result, it is possible to suppress an increase in the time required for the control unit to perform arithmetic processing related to the control of the power assist operation of the drive unit. Therefore, the drive unit is powered from the time when the operation force is input by the operator. It is possible to suppress an increase in the delay in time until the time when the assist operation is started. That is, it is possible to perform a power assist operation with improved responsiveness to the operation of the operator.

It is a front view which showed the structure of the X-ray photographing apparatus. It is a block diagram which showed the whole structure of the X-ray imaging apparatus. It is a perspective view for demonstrating the structure of a moving body. It is a figure for demonstrating the structure of a sensor and a moving body, (A) is a side view for demonstrating the structure of a support part, and (B) is a front view for demonstrating the operation of a moving body. is there. It is a block diagram which showed the structure of the correction circuit part. It is a graph for demonstrating calibration information. It is a figure for demonstrating the control of the grip part own weight correction. It is a figure for demonstrating the calculation of the grip part self-weight correction, (A) is a graph which shows the relationship between a grip part self-weight and an angle θ, (B) is a graph which shows the relationship between a correction signal and an angle θ. Is. It is a figure for demonstrating the control of the support part posture correction, (A) is a front view of a support part, (B) is a plan view of a support part. It is a flowchart for demonstrating the control process of an X-ray photographing apparatus.

(Configuration of X-ray imaging device)
The overall configuration of the X-ray imaging apparatus 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 9.

(Overall configuration of X-ray imaging device)
As shown in FIGS. 1 and 2, the X-ray imaging apparatus 100 according to the present embodiment is a medical X-ray imaging apparatus, and is configured to perform X-ray imaging of a subject P to be imaged. Further, the X-ray imaging device 100 is a general imaging X-ray imaging device provided with a ceiling-traveling X-ray tube suspension device. The X-ray imaging apparatus 100 includes an X-ray tube 1, an X-ray detection unit 2, a moving body 3, a drive unit 4, a sensor 5, a correction circuit unit 6, a control unit 7, a grip unit 8, and the like. A posture detection unit 9 is provided.

As shown in FIG. 1, in the X-ray imaging apparatus 100, the X-ray tube 1 is supported by the moving body 3 so as to be suspended from the ceiling T. The X-ray tube 1 is movably supported in the photographing room by the moving body 3. Further, the X-ray tube 1 includes an X-ray source 11 for irradiating the subject P with X-rays and a collimator 12 for adjusting the X-ray irradiation field.

Further, the X-ray imaging apparatus 100 includes an X-ray detection unit 2 that detects X-rays emitted from the X-ray tube 1. Then, as shown in FIG. 1, the X-ray detection unit 2 stands up the recumbent position imaging table 21 and the subject P for taking a picture in the posture in which the subject P is laid down (the recumbent position). Includes a standing shooting table 22 for shooting in a posture (standing position). The recumbent position detector 21a and the standing position detector 22a are held on the recumbent position imaging table 21 and the standing position photographing table 22 so as to be movable according to the imaging site of the subject P, respectively. The recumbent position detector 21a and the standing position detector 22a are, for example, FPDs (Flat Panel Detectors), and detect X-rays that have passed through the subject P.

The moving body 3 movably supports the X-ray tube 1. As shown in FIG. 1, the moving body 3 moves the X-ray tube 1 from a position where X-ray imaging is performed using the recumbent imaging table 21 to a position where X-ray imaging is performed using the standing imaging table 22. It is configured to be possible. When performing X-ray photography using the recumbent position imaging table 21, the moving body 3 can move the X-ray tube 1 to a position facing the recumbent position detector 21a. In addition, the moving body 3 can move the X-ray tube 1 to a position facing the standing detector 22a when performing X-ray imaging using the standing imaging table 22.

As shown in FIGS. 1 to 3, the moving body 3 has a support portion 31 that rotatably supports the X-ray tube 1 in two directions of the θ direction and the φ direction, and a support portion 31 that supports the support portion 31 in one vertical axis (1 axis in the vertical direction). A vertical moving portion 32 that can move in parallel with the Z-axis) and a horizontal moving portion 33 that can move the vertical moving portion 32 in two horizontal axes (X-axis and Y-axis) are included.

The support portion 31 is attached to the lower portion of the vertical movement portion 32. Further, the support portion 31 is configured to rotatably hold the X-ray tube 1 in the θ direction with respect to the vertical moving portion 32 about the horizontal direction (first rotation axis C1 in FIG. 3). There is. Further, the X-ray tube 1 is configured to be rotatably held in the φ direction with respect to the vertical moving portion 32 about the vertical direction (second rotation axis C2 in FIG. 1).

The vertical moving portion 32 is configured to be able to expand and contract in the vertical direction (Z direction in FIG. 3). The vertical movement portion 32 expands and contracts, so that the support portion 31 is moved in the vertical direction, thereby moving the X-ray tube 1 in the vertical direction.

The horizontal moving portion 33 includes a first horizontal moving portion 33a, a second horizontal moving portion 33b, and a fixed rail 33c. The horizontal moving unit 33 moves the vertical moving unit 32 in the horizontal direction with respect to the ceiling T. Specifically, the fixed rail 33c is fixed to the ceiling T. The first horizontal moving portion 33a is movable with respect to the fixed rail 33c, and extends in a direction orthogonal to the extending direction of the fixed rail 33c (X direction in FIG. 3) (Y direction in FIG. 3). It is provided in. The second horizontal moving portion 33b is attached so as to be movable in the extending direction (Y direction in FIG. 3) of the first horizontal moving portion 33a. That is, while the second horizontal moving portion 33b is stationary with respect to the first horizontal moving portion 33a, the first horizontal moving portion 33a moves on the fixed rail 33c, so that the X-ray tube 1 and the support portion are supported. 31 and the vertical moving portion 32 move in the X direction of FIG. Further, while the first horizontal moving portion 33a is stationary with respect to the fixed rail 33c, the second horizontal moving portion 33b moves on the first horizontal moving portion 33a, so that the X-ray tube 1 and the support portion are supported. 31 and the vertical moving portion 32 move in the Y direction of FIG.

The drive unit 4 includes, for example, a motor and is configured to move the moving body 3. Specifically, the drive unit 4 includes five motors, a first motor, a second motor, a third motor, a fourth motor, and a fifth motor. The first motor rotates the support portion 31 in the θ direction of FIG. 3 with the first rotation axis C1 as the rotation axis with respect to the vertical movement portion 32. The second motor rotates the support portion 31 in the φ direction of FIG. 3 with respect to the vertical movement portion 32 with the second rotation axis C2 as the rotation axis. The third motor moves the vertical moving portion 32 in the Z direction of FIG. The fourth motor moves the first horizontal moving portion 33a in the X direction of FIG. The fifth motor moves the second horizontal moving portion 33b in the Y direction of FIG.

The sensor 5 is, for example, a strain gauge. The sensor 5 detects a force including an operating force F applied by the operator to move the moving body 3. Further, as shown in FIG. 4A, the sensor 5 is arranged so as to connect the grip portion 8 described later to the support portion 31, and the sensor 5 is arranged in accordance with the change in the posture of the support portion 31. Posture also changes.

Further, the sensor 5 is configured to detect the magnitude and direction of the force including the operating force F applied to the grip portion 8 and the own weight of the grip portion 8. As shown in FIG. 4B, the sensor 5 corresponds to each of the three axes orthogonal to each other in the Cx direction, the Cy direction, and the Cz direction based on the magnitude and direction of the force including the operating force F3. It is configured to output one detection signal S1x, S1y, and S1z. The Cx direction, Cy direction, and Cz direction are coordinate systems for the sensor 5. For example, when the posture of the support portion 31 rotates by an angle θ around the first rotation axis C1, the sensor 5 also rotates. Therefore, the Cx direction also rotates by an angle θ.

Further, the sensor 5 can also detect the force applied in the direction of rotating the X-ray tube 1. That is, it is possible to detect the force applied in two rotation directions, the θ direction about the horizontal direction (first rotation axis C1) and the φ direction about the vertical direction (second rotation axis C2). It is configured to be possible. Then, the detection signal S1θ corresponding to the θ direction and the detection signal S1φ corresponding to the φ direction are output. That is, the sensor 5 decomposes the magnitude of the applied force in each of the five directions of the θ direction, the φ direction, the Cx direction, the Cy direction, and the Cz direction into five directions. It is configured to be output as a detection signal S1.

As shown in FIG. 5, the correction circuit unit 6 is configured to include a signal amplification unit 61 and an arithmetic circuit unit 60. The calculation circuit unit 60 includes a signal conversion unit 62, a calculation unit 63, and a storage unit 64. Here, in the present embodiment, the correction circuit unit 6 performs the individual difference correction H1 which is the correction according to the individual difference of the sensor 5 with respect to the detection signal S1 output by the sensor 5 in terms of hardware. Then, the correction signal S2 corresponding to each of the detection signals S1 output by the sensor 5 is output. Further, the correction circuit unit 6 is configured to correct the detection signal S1 by hardware so that the same correction signal S2 is output for the same force applied to the sensor 5. Specifically, the correction circuit unit 6 is configured to output three correction signals S2x, S2y, and S2z corresponding to each of the three detection signals S1 of the detection signals S1x, S1y, and S1z.

As shown in FIG. 4A, the correction circuit unit 6 is arranged in the vicinity of the sensor 5. For example, the signal amplification unit 61, the signal conversion unit 62, the calculation unit 63, the storage unit 64, and the sensor 5 are arranged in the support unit 31 included in the moving body 3. The term "near the sensor 5" as used herein includes not only the vicinity of the position of the sensor 5 but also the position in contact with the sensor 5.

The arithmetic circuit unit 60 includes, for example, a field programmable gate array (FPGA: Field Programmable Gate Array) which is a programmable logic device capable of reconstructing the configuration of a logic circuit. Further, the signal amplification unit 61 includes, for example, an IC (Integrated Circuit). In the present embodiment, "performing in terms of hardware" means that when performing arithmetic processing for performing individual difference correction H1, a predetermined circuit is prepared and processing is performed on the detection signal S1. Means that.

The signal amplification unit 61 is configured to amplify the detection signal S1 output by the sensor 5. That is, it is configured to amplify the detection signal S1 output by the sensor 5 and output the amplified signal S1a which is the amplified detection signal S1.

The signal conversion unit 62 analog-digitally converts the detection signal S1 output by the sensor 5 and transmits the converted detection signal S1 (amplification signal S1a), which is the digital signal S1b.

The calculation unit 63 is configured to perform calculation processing for correcting individual differences in the sensor 5 based on the digital signal S1b.

The storage unit 64 is configured to store in advance calibration information A for outputting the same correction signal S2 for the same force applied to the sensor 5. Then, the correction circuit unit 6 is configured to correct the detection signal S1 by hardware based on the calibration information A stored in the storage unit 64. The details of the individual difference correction H1 will be described later. Further, "identical" means that differences that do not depend on individual differences are regarded as the same. For example, the differences that can be considered within the margin of error due to noise are the same.

The control unit 7 is provided separately from the correction circuit unit 6, and performs the posture correction H2, which is the correction according to the change in the posture of the moving body 3, with respect to the correction signal S2, and also performs the posture correction H2 of the drive unit 4 by software. Controls power assist operation. That is, the control unit 7 software-likes the posture correction H2 for the three correction signals S2x, S2y, and S2z corresponding to the three detection signals S1x, S1y, and S1z corrected by the correction circuit unit 6. The power assist operation of the drive unit 4 is controlled so as to move the vertical movement unit 32 and the horizontal movement unit 33. The detailed operation of the control unit 7 will be described later. Further, in the present embodiment, "performing by software" means that when performing arithmetic processing for performing posture correction H2, processing is performed on the correction signal S2 according to a program instructing what kind of processing is to be performed. Means that.

The grip portion 8 is gripped when the moving body 3 is moved. Specifically, the grip portion 8 has a wheel shape and is provided for gripping when the operator manually moves the moving body 3. The grip portion 8 is arranged so as to be connected to the support portion 31 via the sensor 5.

The posture detection unit 9 detects the posture of the moving body 3. Further, the posture detection unit 9 is configured to output the posture signal S3 as information about each posture. Specifically, the posture detection unit 9 is configured to detect the postures of the support unit 31, the vertical movement unit 32, the first horizontal movement unit 33a, and the second horizontal movement unit 33b. ing. Then, the attitude signal S3θ about the angular position in the θ direction of FIG. 3 of the support portion 31, the attitude signal S3φ about the angular position in the φ direction of FIG. 3, and the Z-axis direction of FIG. 3 of the vertical moving portion 32. About the attitude signal S3Z about the position in, the attitude signal S3X about the position of the first horizontal moving portion 33a in the X direction of FIG. 3, and the position of the second horizontal moving portion 33b in the Y direction of FIG. It is configured to output the attitude signal S3Y of. The posture detection unit 9 includes, for example, a potentiometer.

(Regarding control related to individual difference correction)
FIG. 6 is a graph showing the relationship between the force applied to the sensor 5 (horizontal axis) and the value output by the sensor 5 (vertical axis). The solid line (detection line L1) in FIG. 6 is a straight line linearly interpolated based on the value of the acquired detection signal S1. The alternate long and short dash line (reference line L0) in FIG. 6 is an ideal straight line after the individual difference correction H1 is performed.

As shown in FIG. 6, when the X-ray imaging apparatus 100 is installed in the imaging room, a plurality of detection signals S1 (FIG. 6) are applied by applying a plurality of forces (Fα, Fβ, Fγ in FIG. 6) to the sensor 5. S1α, S1β, S1γ) are acquired. Then, by performing linear interpolation on the acquired plurality of detection signals S1, the detection characteristics (detection line L1 in FIG. 6) of the detection signals S1 of the sensor 5 are acquired. Then, a correction method for correcting the acquired detection characteristic (detection line L1 in FIG. 6) so as to be close to the reference characteristic (reference line L0 in FIG. 6) which is the detection characteristic of the preset reference is acquired. The acquired correction method is stored in the storage unit 64 as calibration information A regarding the sensor 5. Based on the calibration information A stored in the storage unit 64, the correction circuit unit 6 outputs the correction signal S2 by performing the individual difference correction H1 on the detection signal S1.

For example, regarding the magnitude of the force detected by the sensor 5, the detection range is -10 [N] or more and +10 [N] or less. Note that [N] represents Newton, which is a unit representing the magnitude of force. Then, the sensor 5 outputs a value of +0.5 [V] or more and +4.5 [V] or less as the detection signal S1 according to the magnitude of the detected force. Note that [V] represents a volt, which is a unit representing the magnitude of voltage. Here, as a reference characteristic (reference line L0 in FIG. 6), for example, when a force of −5 [N], 0 [N], or +2 [N] is input with respect to the Cx direction of the sensor 5, the output is output. The detection signals S1x to be generated are +1.5 [V], +2.5 [V], and +2.9 [V], respectively. The power supply of the sensor 5 is 5 [V], but the values of 0 [V] and +5 [V] are output only when an abnormality such as disconnection occurs, and are not output within the detection range. ing.

Then, since the detection signal S1 output when a force is actually applied differs depending on the individual difference of the sensor 5, the correction circuit unit 6 performs the individual difference correction H1. For example, the individual difference correction H1 so as to satisfy the reference characteristics with respect to the detection signal S1 output when a force of three points (-5 [N], 0 [N], 5 [N]) is applied in advance. By performing the above, the individual difference correction H1 is performed so that the detection signals S1 corresponding to each of the three points indicate −5 [N], 0 [N], and 5 [N]. Then, the calibration information A for linear interpolation from the output values at the three points is stored in the storage unit 64. That is, when a force of -5 [N], 0 [N], or +2 [N] is applied to the sensor 5, the correction circuit unit 6 sets the correction signal S2 to -5 [N]. , 0 [N], +2 [N] are output so that the individual difference correction H1 is performed. If no force is applied to the sensor 5, 0 is output.

As described above, when the magnitude of the force applied to the sensor 5 is the same, the correction circuit unit 6 outputs the same value as the correction signal S2 regardless of the individual difference of the sensor 5. Individual difference correction H1 is performed on the detection signal S1 of the sensor 5. That is, the correction circuit unit 6 outputs a correction signal S2 indicating each of the forces applied to the sensor 5 decomposed in the Cx direction, the Cy direction, and the Cz direction, regardless of the individual difference of the sensor 5.

(About control related to posture correction)
The control unit 7 performs the grip portion self-weight correction H2a and the support portion posture correction H2b as the posture correction H2. Based on the posture signal S3 output from the posture detection unit 9, the control unit 7 corrects the correction signal S2 output from the correction circuit unit 6 according to the weight of the grip portion 8. The H2a and the support portion posture correction H2b, which is a correction according to a change in the posture of the support portion 31, are performed by software, and the power assist operation of the drive unit 4 is controlled. That is, the control unit 7 performs the grip portion own weight correction H2a on the correction signal S2 (S2x, S2y, S2z) output by the correction circuit unit 6 to obtain the own weight correction signal S4 (S4x, S4y, S4z). Output. Then, the control unit 7 outputs the posture correction signal S5 (S5x, S5y, S5z) by performing the support portion posture correction H2b with respect to the self-weight correction signal S4 (S4x, S4y, S4z). The self-weight correction signals S4x, S4y, and S4z are values obtained by performing the grip portion self-weight correction H2a on each of the correction signals S2x, S2y, and S2z, respectively. Further, the posture correction signals S5x, S5y, and S5z are values obtained by performing support portion posture correction H2b on each of the self-weight correction signals S4x, S4y, and S4z, respectively.

<About gripping part weight correction>
As shown in FIG. 7, the control unit 7 acquires a change in the posture of the grip unit 8 based on the posture signal S3θ output by the posture detection unit 9. Then, based on the posture of the grip portion 8, the grip portion self-weight correction H2a, which is a correction for the force applied to the sensor 5 by the self-weight of the grip portion 8, is performed separately from the operating force F. That is, in a state where the operating force F is not applied to the sensor 5 (a state in which the operating force F is 0), the grip portion self-weight correction H2a is performed so that the self-weight correction signal S4 becomes 0. Specifically, since the sensor 5 is configured to detect the magnitude and direction of the force including the operating force F applied to the grip portion 8 and the own weight of the grip portion 8, the correction circuit unit 6 is used to detect the magnitude and direction of the force. The output correction signal S2 is a value indicating a force including the operating force F and the own weight of the grip portion 8. By performing the grip portion self-weight correction H2a on the correction signal S2, the control unit 7 acquires the value obtained by extracting the operating force F excluding the self-weight of the grip portion 8 as the self-weight correction signal S4. That is, the control unit 7 outputs a self-weight correction signal S4 (S4x, S4y, S4z) indicating each of the forces in which the operating force F is decomposed in the Cx direction, the Cy direction, and the Cz direction.

When the grip portion 8 (support portion 31) is rotated by an angle θ around the first rotation axis C1, the values of the self-weight correction signals S4x, S4y, and S4z are expressed by the equations (1), (2), and S4z, respectively. It is expressed as (3).
S4x = S2x-Mx
= S2x-Mx (0) cosθ ... (1)
S4y = S2y-My
= S2y-My (90) sinθ ... (2)
S4z = S2z ... (3)
Note that Mx is the value of the correction signal S2x based on the detection signal S1x detected by the sensor 5 due to the weight of the grip portion 8 when the grip portion 8 is rotated by an angle θ. Further, My is a value of the correction signal S2y based on the detection signal S1y detected by the sensor 5 by the weight of the grip portion 8 when the grip portion 8 is rotated by an angle θ. Further, Mx (0) represents the value of Mx when the value of θ is 0 degrees. Further, My (90) represents the value of My when the value of θ is 90 degrees.

Note that FIG. 8A is a graph showing the angle θ (horizontal axis) and the values of Mx and My (vertical axis). That is, it is a graph showing the relationship between the angle θ and the values of the correction signals S2x and S2y acquired by the own weight of the grip portion 8 when the operating force F is not applied. The solid line in FIG. 8 (A) represents the value of Mx, and the alternate long and short dash line in FIG. 8 (A) represents the value of My. FIG. 8B is a graph showing the angle θ (horizontal line) and the value (vertical axis) of the correction signal S2 output by the correction circuit unit 6. The solid line in FIG. 8B represents the value of the correction signal S2x in the Cx direction, and the alternate long and short dash line in FIG. 8B represents the value of the correction signal S2y in the Cy direction. As shown in FIG. 8, since the value exerted by the weight of the gripping portion 8 on the correction signals S2x and S2y can be calculated from the angle θ, the gripping is performed based on the equations (1) and (2) and the posture signal S3θ. In order to detect the magnitude and direction of the operating force F excluding the own weight of the unit 8, the control unit 7 performs the grip portion own weight correction H2a.

<About support posture correction>
Further, as shown in FIGS. 9A and 9B, the control unit 7 acquires a change in the attitude of the support unit 31 based on the attitude signals S3θ and S3φ output by the attitude detection unit 9. Then, based on the posture of the support portion 31, the magnitude and direction of the force detected by the sensor 5 in the Cx direction, the Cy direction, and the Cz direction are set in the X direction (the direction in which the fixed rail 33c extends) and the Y direction (the first horizontal direction). The support portion posture correction H2b, which is a correction for converting the coordinates between the moving portion 33a (extending direction) and the Z direction (vertical direction moving portion 32 extending direction), is performed. Specifically, the control unit 7 uses the posture correction signal S5x indicating the magnitude of the force in the X direction and the magnitude of the force in the Y direction for the self-weight correction signal S4 acquired by performing the grip portion self-weight correction H2a. The posture correction signal S5y representing the above and the posture correction signal S5z representing the magnitude of the force in the Z direction are corrected. When the support portion 31 (grip portion 8) is rotated by an angle θ around the first rotation axis C1 and rotated by an angle φ around the second rotation axis C2, the posture correction signal S5 (S5x, S5y, S5z) and , The relationship with the self-weight correction signal S4 (S4x, S4y, S4z) is expressed as the equations (4), (5), and (6), respectively.
S5x = (S4ycosθ-S4xsinθ) cosφ + S4zsinφ ... (4)
S5y = S4zcosφ- (S4ycosθ-S4xsinθ) sinφ ... (5)
S5z = S4xcosθ + S4ysinθ ... (6)
As described above, the control unit 7 applies the operating force F represented by the three directions of the Cx direction, the Cy direction, and the Cz direction to the X direction, the Y direction, and the Z direction by the support portion posture correction H2b. The coordinates are transformed so that they are represented by three directions.

(Regarding control related to the operation of the drive unit)
The control unit 7 changes the magnitude and direction of the operating force F based on the detection signal S1 to which the individual difference correction H1 and the posture correction H2 (the grip portion own weight correction H2a and the support portion posture correction H2b) are applied. Convert in each direction of movement of 3. Then, the control unit 7 controls the power assist operation of the drive unit 4 so that an assist force obtained by multiplying the converted operating force F by the assist ratio is generated as in the equation (7).
m ・ a ＝ FF _R ＋ k ・ F ・ ・ ・ (7)
Incidentally, m is the mass of the movable body 3, a is the acceleration, F is the operation force applied to the grip portion 8, F _R is resistance, k is the amount of the assist ratio with respect to the operating force F. m is, for example, several hundred kg. k is, for example, about 2 or more and 10 or less. That is, a force of about 2 times or more and 10 times or less with respect to the operating force F is applied as an assist force in the power assist operation.

(Control processing by the X-ray imaging apparatus 100)
Next, with reference to FIG. 10, a control processing flow related to X-ray imaging by the X-ray imaging apparatus 100 according to the present embodiment will be described. Further, steps 101 to 104 show the control process by the correction circuit unit 6, and steps 105 to 107 show the control process by the control unit 7.

First, in step 101, the detection signal S1 output by the sensor 5 is acquired.

Next, in step 102, the acquired detection signal S1 is amplified by the signal amplification unit 61 and output as an amplification signal S1a.

Next, in step 103, the amplified signal S1a output by the signal amplification unit 61 is analog-digital converted by the signal conversion unit 62 and output as a digital signal S1b.

Next, in step 104, the digital signal S1b output by the signal conversion unit 62 is subjected to individual difference correction H1 by the calculation unit 63 based on the calibration information A stored in the storage unit 64, and the correction signal is corrected. It is output as S2.

Next, in step 105, the correction signal S2 in which the individual difference correction H1 is performed by the correction circuit unit 6 is subjected to the grip portion self-weight correction H2a and output as the self-weight correction signal S4.

Next, in step 106, the self-weight correction signal S4 in which the grip portion self-weight correction H2a is performed is subjected to the support portion posture correction H2b and output as the posture correction signal S5.

Next, in step 107, the power assist operation is performed by controlling the operation of the drive unit 4 based on the operating force F (posture correction signal S5). That is, the power assist operation is performed by controlling the operation of the drive unit 4 by the posture correction signal S5 acquired based on the operating force F.

(Effect of embodiment)
In this embodiment, the following effects can be obtained.

In the present embodiment, the X-ray imaging apparatus 100 has at least one of an X-ray tube 1 that irradiates the subject P with X-rays and an X-ray detection unit 2 that detects the X-rays emitted from the X-ray tube 1. An X-ray imaging device 100 that performs a power assist operation when manually moved by an operator, and moves with a moving body 3 that movably supports at least one of an X-ray tube 1 and an X-ray detection unit 2. The individual sensor 5 with respect to the drive unit 4 for moving the body 3, the sensor 5 for detecting the force including the operation force F for moving the moving body 3 by the operator, and the detection signal S1 output by the sensor 5. A correction circuit unit 6 that performs individual difference correction H1 that is a correction according to a difference in hardware, and a correction signal S2 that is a detection signal S1 that is provided separately from the correction circuit unit 6 and is corrected by the correction circuit unit 6. On the other hand, the posture correction H2, which is a correction according to the change in the posture of the moving body 3, is performed by software, and the control unit 7 for controlling the power assist operation of the drive unit 4 is provided. As a result, the arithmetic processing for performing software-like correction according to the individual difference of the sensor 5 by the control unit 7 becomes unnecessary. Therefore, the processing capacity of the control unit 7 can be devoted to the arithmetic processing of the posture correction H2 and the control of the power assist operation. As a result, it is possible to suppress an increase in the time required for the control unit 7 to perform arithmetic processing related to the control of the power assist operation of the drive unit 4, so that the drive unit 4 starts from the time when the operation force F is input by the operator. It is possible to suppress an increase in the delay in time until the start of the power assist operation. In other words, it is possible to perform a power assist operation with improved responsiveness to the operation of the operator.

Further, in the present embodiment, the correction circuit unit 6 is configured to correct the detection signal S1 by hardware so that the same correction signal S2 is output for the same force applied to the sensor 5. ing. As a result, the control unit 7 can perform the same processing on the correction signal S2 output from the correction circuit unit 6, so that it is not necessary to change the calculation processing according to the individual difference of the sensor 5. As a result, it is possible to suppress an increase in the processing load of the control unit 7, so that it is possible to suppress an increase in the delay in performing the power assist operation with respect to the operating force F of the operator.

Further, in the present embodiment, the correction circuit unit 6 includes a storage unit 64 in which calibration information A for outputting the same correction signal S2 for the same force applied to the sensor 5 is stored in advance. The detection signal S1 is hardware-corrected based on the calibration information A stored in the unit 64. As a result, the correction circuit unit 6 stores the correction method as a reference in advance as the calibration information A, so that the correction according to the individual difference can be easily performed.

Further, in the present embodiment, the sensor 5 is configured to output three detection signals S1 corresponding to each of the three axes orthogonal to each other based on the magnitude and direction of the force including the operating force F. The moving body 3 has a support portion 31 that rotatably supports the X-ray tube 1, a vertical movement portion 32 that can move the support portion 31 to one axis in the vertical direction, and a vertical movement portion 32 in the horizontal direction. The control unit 7 includes a horizontal movement unit 33 that can move in two axes, and the control unit 7 corrects the attitude of the three correction signals S2 corresponding to each of the three detection signals S1 corrected by the correction circuit unit 6. H2 is performed by software, and the power assist operation of the drive unit 4 is controlled so as to move the vertical movement unit 32 and the horizontal movement unit 33. As a result, the operating force F applied by the operator is three-dimensionally detected, and the vertical moving portion 32 is movable in one direction and the horizontal moving portion 33 is movable in two directions, which are orthogonal to each other. It can be converted in a total of 3 directions. As a result, the control unit 7 can control the moving body 3 to move based on each of the converted operating forces F, so that the power assist is performed by a force proportional to the magnitude and direction of the operating force F. It can be controlled to perform a power assist operation that performs the operation. Therefore, since the operator can move the moving body 3 as intended by himself / herself, it is possible to suppress an increase in the burden on the operator.

Further, in the present embodiment, the grip portion 8 that grips the moving body 3 when moving the moving body 3 and the posture detecting unit 9 that detects the posture of the moving body 3 are further provided, and the sensor 5 is added to the grip portion 8. The control unit 7 is configured to detect a force including the operating force F and the weight of the gripping unit 8, and the control unit 7 is output from the correction circuit unit 6 based on the attitude signal S3 output from the attitude detection unit 9. With respect to the correction signal S2, the grip portion own weight correction H2a, which is a correction according to the own weight of the grip portion 8, and the support portion posture correction H2b, which is a correction according to the change in the posture of the support portion 31, are performed by software. At the same time, it is configured to control the power assist operation of the drive unit 4. As a result, the posture detection unit 9 can detect the posture of the moving body 3 and perform the grip portion self-weight correction H2a and the support portion posture correction H2b based on the detected values indicating the posture of the moving body 3. As a result, since the power assist operation can be performed in response to the change in the posture of the device, the power assist operation corresponding to the operation force F applied by the operator can be performed. Then, since the movement of the moving body 3 in the direction not intended by the operator is suppressed, the burden on the operator due to the movement of the moving body 3 in the unintended direction can be reduced.

Further, in the present embodiment, the correction circuit unit 6 is arranged in the vicinity of the sensor 5. As a result, the transmission distance from the output of the detection signal S1 detected by the sensor 5 to the correction by the correction circuit unit 6 can be reduced. As a result, the electrical noise that the detection signal S1 receives from the outside can be suppressed, so that a more accurate power assist operation can be performed with respect to the operating force F applied by the operator.

Further, in the present embodiment, the correction circuit unit 6 analog-digitally converts the signal amplification unit 61 that amplifies the detection signal S1 output by the sensor 5 and the detection signal S1 output by the sensor 5 into a detection signal. A signal conversion unit 62 that outputs a digital signal S1b converted by S1 and a calculation unit 63 that performs arithmetic processing based on the digital signal S1b are included, and a signal amplification unit 61, a signal conversion unit 62, a calculation unit 63, and a sensor. Reference numeral 5 is arranged on the support portion 31. Here, when the signal conversion unit 62 and the calculation unit 63 are arranged at positions separate from the support unit 31 and separated from the sensor 5, electrical noise is generated in the detection signal S1 while the detection signal S1 is transmitted. It is considered that there is a risk of receiving. In consideration of this point, the detection signal detected by the sensor 5 is detected by arranging the signal amplification unit 61, the signal conversion unit 62, the calculation unit 63, and the sensor 5 on the support unit 31 as in the above embodiment. Before S1 receives electrical noise from the outside, it is amplified and analog-digitally converted to perform individual difference correction H1. As a result, the electrical noise that the detection signal S1 receives from the outside can be suppressed, so that a more accurate power assist operation can be performed with respect to the operating force F applied by the operator.

(Modification example)
It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the claims rather than the description of the above-described embodiment, and further includes all modifications (modifications) within the meaning and scope equivalent to the claims.

For example, in the above embodiment, an example in which a power assist operation is performed in a general radiographing X-ray imaging apparatus 100 provided with a ceiling-traveling X-ray tube suspension device is shown, but the present invention is not limited to this. In the present invention, the power assist operation may be performed in an X-ray imaging apparatus provided with a close-up fluoroscopy table.

Further, in the above embodiment, an example in which the power assist operation is performed in the movement of the X-ray tube 1 is shown, but the present invention is not limited to this. In an X-ray imaging apparatus provided with a close-up fluoroscopy table, a power assist operation may be performed by detecting an operating force F using a sensor 5 when moving a top plate on which a subject P is placed. .. Further, by providing the grip portion 8 in each of the X-ray tube 1 and the X-ray detection unit 2, the operating force F is detected in the movement of both the X-ray tube 1 and the X-ray detection unit 2, and the power assist operation is performed. You may do it.

Further, in the above embodiment, the correction circuit unit 6 is configured to correct the detection signal S1 by hardware so that the same correction signal S2 is output for the same force applied to the sensor 5. However, the present invention is not limited to this. For example, even if the magnitude of the force applied to the sensor 5 is different, the correction signal S2 having the same magnitude may be output.

Further, in the above embodiment, the correction circuit unit 6 includes a storage unit 64 in which calibration information A for outputting the same correction signal S2 for the same force applied to the sensor 5 is stored in advance. Although an example in which the detection signal S1 is configured to be corrected by hardware based on the calibration information A stored in the unit 64 is shown, the present invention is not limited to this. For example, the correction circuit unit 6 may be configured to acquire the calibration information A by calculating a correction method based on a reference detection characteristic.

Further, in the above embodiment, the sensor 5 is configured to output three detection signals S1 corresponding to each of the three axes orthogonal to each other based on the magnitude and direction of the force including the operating force F. The moving body 3 has a support portion 31 that rotatably supports the X-ray tube 1, a vertical movement portion 32 that can move the support portion 31 to one axis in the vertical direction, and a vertical movement portion 32 in the horizontal direction. The control unit 7 includes a horizontal moving unit 33 that can move in two axes, and the control unit 7 corrects the attitude of the three correction signals S2 corresponding to each of the three detection signals S1 corrected by the correction circuit unit 6. An example is shown in which H2 is performed by software and the power assist operation of the drive unit 4 is controlled so as to move the vertical movement unit 32 and the horizontal movement unit 33. Not limited to this. For example, the correction signal S2 may be output for more than three detection signals S1. That is, it is configured to output not only the three correction signals S2 for the total of three detection signals S1 in the X direction, the Y direction, and the Z direction, but also the correction signals S2 in the θ direction and the φ direction. You may be.

Further, in the above embodiment, the grip portion 8 that grips the moving body 3 when moving the moving body 3 and the posture detecting unit 9 that detects the posture of the moving body 3 are further provided, and the sensor 5 is added to the grip portion 8. The control unit 7 is configured to detect a force including the operating force F and the own weight of the grip unit 8, and the control unit 7 is output from the correction circuit unit 6 based on the attitude signal S3 output from the attitude detection unit 9. With respect to the correction signal S2, the grip portion own weight correction H2a, which is a correction according to the own weight of the grip portion 8, and the support portion posture correction H2b, which is a correction according to the change in the posture of the support portion 31, are performed by software. Although an example is shown in which the drive unit 4 is configured to control the power assist operation, the present invention is not limited to this. For example, it may be configured to detect the operating force F applied to other parts of the moving body 3 instead of the operating force F applied to the grip portion 8. Further, the posture may not be detected by the posture detecting unit 9, but the posture may be estimated from the operation history of the driving unit 4.

Further, in the above embodiment, the correction circuit unit 6 is arranged in the vicinity of the sensor 5, but the present invention is not limited to this. That is, the correction circuit unit 6 and the sensor 5 may be arranged apart from each other. For example, the correction circuit unit 6 may be arranged not in the support unit 31 but in the vertical movement unit 32.

Further, in the above embodiment, the correction circuit unit 6 analog-digitally converts the signal amplification unit 61 that amplifies the detection signal S1 output by the sensor 5 and the detection signal S1 output by the sensor 5 into a detection signal. The signal amplification unit 61, the signal conversion unit 62, the calculation unit 63, and the sensor 5 include a signal conversion unit 62 for transmitting the digital signal S1b converted by S1 and a calculation unit 63 for performing arithmetic processing based on the digital signal S1b. Although an example of being arranged on the moving body 3 is shown, the present invention is not limited to this. For example, the calculation unit 63 may be arranged at a place separate from the moving body 3. That is, the calculation unit 63 may be arranged in the vicinity of the control unit 7.

Further, in the above embodiment, an example in which the calibration information A is stored when the X-ray imaging apparatus 100 is installed in the imaging room is shown, but the present invention is not limited to this. For example, the calibration information A may be stored at the time of shipment from the factory. Further, the calibration information A may be stored every time the engine is started.

Further, in the above embodiment, the sensor 5 is arranged on the support portion 31, but the present invention is not limited to this. For example, it may be arranged between the vertical moving portion 32 and the horizontal moving portion 33.

[Aspect]
It will be understood by those skilled in the art that the above exemplary embodiments are specific examples of the following embodiments.

(Item 1)
When the operator manually moves at least one of the X-ray tube that irradiates the subject with X-rays and the X-ray detection unit that detects the X-rays emitted from the X-ray tube, a power assist operation is performed. It is an X-ray imaging device to perform
A moving body that movably supports at least one of the X-ray tube and the X-ray detector,
A drive unit that moves the moving body and
A sensor that detects a force including an operating force for moving the moving body by the operator, and a sensor.
A correction circuit unit that performs hardware-like correction of individual differences, which is correction according to individual differences of the sensor, with respect to the detection signal output by the sensor.
The correction signal, which is the detection signal corrected by the correction circuit unit, is provided separately from the correction circuit unit, and the posture correction, which is the correction according to the change in the posture of the moving body, is performed by software. An X-ray imaging device including a control unit that controls the power assist operation of the drive unit.

(Item 2)
Item 2. The item 1 wherein the correction circuit unit is configured to hardware-correct the detection signal so that the same correction signal is output for the same force applied to the sensor. X-ray imaging device.

(Item 3)
The correction circuit unit includes a storage unit in which calibration information for outputting the same correction signal for the same force applied to the sensor is stored in advance, and the calibration information stored in the storage unit. Item 2. The X-ray imaging apparatus according to item 2, which is configured to correct the detection signal in terms of hardware based on the above.

(Item 4)
The sensor is configured to output the three detection signals corresponding to each of the three axes orthogonal to each other based on the magnitude and direction of the force including the operating force.
The moving body includes a support portion that rotatably supports the X-ray tube, a vertical moving portion that can move the supporting portion in one vertical axis, and two horizontal axes that support the vertical moving portion. Including a movable part in the horizontal direction, which can be moved to
The control unit performs the posture correction on the three correction signals corresponding to each of the three detection signals corrected by the correction circuit unit by software, and also performs the vertical movement unit and the horizontal movement unit. The X-ray imaging apparatus according to any one of items 1 to 3, which is configured to control the power assist operation of the drive unit so as to move the direction moving unit.

(Item 5)
A grip portion to be gripped when moving the moving body, and a grip portion to be gripped.
A posture detection unit for detecting the posture of the moving body is further provided.
The sensor is configured to detect a force including the operating force applied to the grip portion and the own weight of the grip portion.
Based on the posture signal output from the posture detection unit, the control unit corrects the correction signal output from the correction circuit unit according to the weight of the grip unit. Item 4. The X-ray imaging according to item 4, which is configured to perform software-like correction of the support portion posture, which is a correction according to a change in the posture of the support portion, and to control the power assist operation of the drive unit. apparatus.

(Item 6)
The X-ray imaging apparatus according to any one of items 1 to 5, wherein the correction circuit unit is arranged in the vicinity of the sensor.

(Item 7)
The correction circuit unit has a signal amplification unit that amplifies the detection signal output by the sensor, analog-digital conversion of the detection signal output by the sensor, and transmission of the converted digital signal. An item in which the signal amplification unit, the signal conversion unit, the calculation unit, and the sensor are arranged on the moving body, including a signal conversion unit and a calculation unit that performs calculation processing based on the digital signal. 6. The X-ray imaging apparatus according to 6.

1 X-ray tube 2 X-ray detection unit 3 Moving body 4 Drive unit 5 Sensor 6 Correction circuit unit 7 Control unit 8 Grip unit 9 Attitude detection unit 31 Support unit 32 Vertical movement unit 33 Horizontal movement unit 61 Signal amplification unit 62 Signal Conversion unit 63 Calculation unit 64 Storage unit 100 X-ray imaging device A Calibration information F Operating force H1 Individual difference correction H2 Attitude correction H2a Grip unit own weight correction H2b Support part Attitude correction P Subject S1 Detection signal S1b Digital signal S2 Correction signal Attitude signal

Claims (7)

When the operator manually moves at least one of the X-ray tube that irradiates the subject with X-rays and the X-ray detection unit that detects the X-rays emitted from the X-ray tube, a power assist operation is performed. It is an X-ray imaging device to perform
A moving body that movably supports at least one of the X-ray tube and the X-ray detector,
A drive unit that moves the moving body and
A sensor that detects a force including an operating force for moving the moving body by the operator, and a sensor.
A correction circuit unit that performs hardware-like correction of individual differences, which is correction according to individual differences of the sensor, with respect to the detection signal output by the sensor.
The correction signal, which is the detection signal corrected by the correction circuit unit, is provided separately from the correction circuit unit, and the posture correction, which is the correction according to the change in the posture of the moving body, is performed by software. An X-ray imaging device including a control unit that controls the power assist operation of the drive unit. The correction circuit unit is configured to correct the detection signal in hardware so that the same correction signal is output for the same force applied to the sensor, according to claim 1. X-ray imaging device. The correction circuit unit includes a storage unit in which calibration information for outputting the same correction signal for the same force applied to the sensor is stored in advance, and the calibration information stored in the storage unit. The X-ray imaging apparatus according to claim 2, which is configured to correct the detection signal in terms of hardware based on the above. The sensor is configured to output the three detection signals corresponding to each of the three axes orthogonal to each other based on the magnitude and direction of the force including the operating force.
The moving body includes a support portion that rotatably supports the X-ray tube, a vertical moving portion that can move the supporting portion in one vertical axis, and two horizontal axes that support the vertical moving portion. Including a movable part in the horizontal direction, which can be moved to
The control unit performs the posture correction on the three correction signals corresponding to each of the three detection signals corrected by the correction circuit unit by software, and also performs the vertical movement unit and the horizontal movement unit. The X-ray imaging apparatus according to any one of claims 1 to 3, which is configured to control the power assist operation of the drive unit so as to move the direction moving unit. A grip portion to be gripped when moving the moving body, and a grip portion to be gripped.
A posture detection unit for detecting the posture of the moving body is further provided.
The sensor is configured to detect a force including the operating force applied to the grip portion and the own weight of the grip portion.
Based on the posture signal output from the posture detection unit, the control unit corrects the correction signal output from the correction circuit unit according to the weight of the grip unit. The X-ray according to claim 4, wherein the support portion posture correction, which is a correction according to a change in the posture of the support portion, is performed by software and the power assist operation of the drive unit is controlled. Shooting device. The X-ray imaging apparatus according to any one of claims 1 to 5, wherein the correction circuit unit is arranged in the vicinity of the sensor. The correction circuit unit has a signal amplification unit that amplifies the detection signal output by the sensor, analog-digital conversion of the detection signal output by the sensor, and transmission of the converted digital signal. A claim that includes a signal conversion unit and a calculation unit that performs arithmetic processing based on the digital signal, and the signal amplification unit, the signal conversion unit, the calculation unit, and the sensor are arranged on the moving body. Item 6. The X-ray imaging apparatus according to Item 6.

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