X-ray imaging apparatus and positioning assist device for X-ray imaging apparatus

Abstract

To provide an X-ray imaging apparatus which can suppress an uncomfortable feeling from being given to a subject in a case of positioning an X-ray irradiation unit due to guide light with relatively high light intensity that is irradiated in a case of positioning the X-ray irradiation unit in the time of X-ray imaging.SOLUTION: An X-ray imaging apparatus 100 comprises: an X-ray irradiation unit 1; an X-ray detection unit 2; a guide light irradiation unit 41; an optical camera 42 (region information acquisition unit); and a unit side control unit 43 (guide light irradiation control unit). The unit side control unit 43 performs control of setting a guide light irradiation restriction region 80, acquiring a guide light irradiation region 70 on the basis of an optical image 60 (region acquisition information), and stopping irradiation of the guide light 50 in a portion overlapping at least the guide light irradiation restriction region 80 when the guide light irradiation region 70 overlaps the guide light irradiation restriction region 80, and control of reducing light intensity of the guide light 50 irradiated from the guide light irradiation unit 41.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to an X-ray imaging apparatus and a positioning assist device for an X-ray imaging apparatus.

Background Art

[0002] Conventionally, X-ray imaging apparatuses are known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a mobile X-ray imaging apparatus including an X-ray irradiation unit that irradiates X-rays and a cart on which the X-ray irradiation unit is mounted. The X-ray irradiation unit is provided with an irradiation field lamp that irradiates visible light to indicate the irradiation field of the X-rays irradiated from the X-ray irradiation unit. This X-ray imaging apparatus can indicate the X-ray irradiation field by the guide light of the visible light irradiated from the irradiation field lamp when positioning the X-ray irradiation apparatus during X-ray imaging. Although not specified in Patent Document 1, in a conventional X-ray imaging apparatus as described in Patent Document 1, while the irradiation field lamp irradiates visible light with a light intensity harmless to the human body as guide light, relatively high-intensity visible light is irradiated as guide light to make the region indicating the X-ray irradiation field easier for the user to visually recognize.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in conventional X-ray imaging devices such as the one described in Patent Document 1 above, when imaging the area around the subject's face, such as when imaging the chest, the guide light indicating the X-ray field may be directed towards the subject's eyes when positioning the X-ray irradiation device during X-ray imaging. In this case, a guide light with a relatively high light intensity is directed towards the subject's eyes until the user stops the irradiation of the guide light. Therefore, there is a problem that the relatively high light intensity guide light emitted when positioning the X-ray irradiation device during X-ray imaging may cause discomfort to the subject.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide an X-ray imaging apparatus and a positioning assist device for an X-ray imaging apparatus that can suppress discomfort to the subject during positioning of the X-ray irradiation area caused by guide light with relatively high light intensity that is emitted when positioning the X-ray irradiation area during X-ray imaging. [Means for solving the problem]

[0007] The X-ray imaging apparatus in the first aspect of this invention comprises: an X-ray irradiation unit that irradiates a subject with X-rays; an X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the subject; a guide light irradiation unit that irradiates an X-ray irradiation area or a guide light indicating the center position of the X-ray irradiation area to be irradiated with X-rays by the X-ray irradiation unit; an optical camera that acquires an optical image for acquiring the guide light irradiation area to be irradiated with guide light by the guide light irradiation unit; and a guide light irradiation control unit that sets a guide light irradiation restriction area including an area overlapping with at least the position of the subject's eyes, and controls the irradiation of guide light by the guide light irradiation unit based on the set guide light irradiation restriction area, wherein the guide light irradiation control unit ,lightBased on the optical image acquired by the camera, the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit is obtained. Based on the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit, the guide light irradiation area is geometrically calculated. If the guide light irradiation area overlaps with the guide light irradiation restriction area, the system is configured to either stop the irradiation of guide light in at least the portion overlapping with the guide light irradiation restriction area, or to reduce the light intensity of the guide light emitted from the guide light irradiation unit.

[0008] A positioning assist device for an X-ray imaging apparatus in a second aspect of this invention includes an X-ray irradiation unit for irradiating a subject with X-rays, and an X-ray detection unit for detecting X-rays irradiated from the X-ray irradiation unit and transmitted through the subject. The positioning assist device is attached to the X-ray irradiation unit of an X-ray imaging apparatus and includes a guide light irradiation unit for irradiating a guide light that indicates the position of the X-ray irradiation region or the center of the X-ray irradiation region to which X-rays are irradiated by the X-ray irradiation unit, and a mechanism for acquiring the guide light irradiation region to which the guide light is irradiated by the guide light irradiation unit. Optical image Get Optical camera The system includes a guide light irradiation restriction area which includes at least an area overlapping the eye position of the subject, and a guide light irradiation control unit which controls the irradiation of guide light by the guide light irradiation unit based on the set guide light irradiation restriction area, and the guide light irradiation control unit Optical camera Obtained by The relative positional relationship between the X-ray irradiation unit and the X-ray detection unit is obtained based on the optical image. Based on this, the guide light irradiation area Geometrically calculated Furthermore, when the guide light irradiation area overlaps with the guide light irradiation restriction area, the system is configured to either stop the irradiation of guide light in at least the portion overlapping with the guide light irradiation restriction area, or to reduce the light intensity of the guide light emitted from the guide light irradiation unit. [Effects of the Invention]

[0009] According to the X-ray imaging apparatus in the first aspect of the present invention and the positioning assist device for the X-ray imaging apparatus in the second aspect, when the guide light irradiation area overlaps with the guide light irradiation restriction area which includes an area that overlaps with at least the position of the subject's eyes, the guide light irradiation control unit controls the stopping of guide light irradiation or reduces the light intensity of the guide light emitted from the guide light irradiation unit in at least the portion that overlaps with the guide light irradiation restriction area. As a result, even if the user does not perform an operation to stop the irradiation of the guide light, if the guide light is irradiated into an area that overlaps with the position of the subject's eyes, the guide light irradiation control unit controls the stopping of guide light irradiation or reduces the light intensity of the guide light emitted from the guide light irradiation unit. As a result, it is possible to suppress the discomfort caused to the subject due to relatively high-intensity guide light being irradiated towards the subject's eyes. This makes it possible to provide an X-ray imaging apparatus and a positioning assist device for an X-ray imaging apparatus that can suppress discomfort to the subject during the positioning of the X-ray irradiation area caused by guide light with relatively high light intensity that is emitted when positioning the X-ray irradiation area during X-ray imaging. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram illustrating the configuration of an X-ray imaging apparatus according to the first embodiment. [Figure 2] This is a functional block diagram illustrating the configuration of an X-ray imaging apparatus according to the first embodiment. [Figure 3] This is a schematic diagram illustrating the X-ray detection unit and marker. [Figure 4] This is a diagram illustrating the configuration of a positioning assist unit for an X-ray imaging apparatus according to the first embodiment. [Figure 5] This diagram illustrates the detection of relative positional and angular relationships by a positioning assistance unit. [Figure 6] This is a diagram illustrating the irradiation of guide light by the guide light irradiation unit of the first embodiment. [Figure 7]This is a diagram for explaining the imaging of an optical image by a positioning assistance unit. [Figure 8] This is a diagram for explaining a method for obtaining a guide light irradiation area by the positioning assistance unit of the first embodiment. [Figure 9] This is a diagram for explaining a method for setting a guide light irradiation restriction area according to the first embodiment. [Figure 10] This is a diagram showing a guide light irradiation restriction area set by the guide light irradiation control unit of the first embodiment. [Figure 11] This is a diagram showing the irradiation of guide light when the irradiation of guide light is not controlled by the guide light irradiation control unit. [Figure 12] This is the first diagram for explaining the control of the irradiation of guide light according to the first embodiment. [Figure 13] This is the second diagram for explaining the control of the irradiation of guide light according to the first embodiment. [Figure 14] This is a diagram for explaining a method for obtaining a guide light irradiation area by the positioning assistance unit of the second embodiment. [Figure 15] This is a diagram for explaining a method for setting a guide light irradiation restriction area according to the second embodiment. [Figure 16] This is the first diagram for explaining the control of the irradiation of guide light according to the second embodiment. [Figure 17] This is the second diagram for explaining the control of the irradiation of guide light according to the second embodiment. [Figure 18] This is a diagram for explaining the control of the irradiation of guide light according to the third embodiment. [Figure 19] This is a functional block diagram for explaining the configuration of an X-ray imaging apparatus according to the fourth embodiment. [Figure 20] This is a diagram for explaining the irradiation of guide light by the guide light irradiation unit of the fourth embodiment. [Figure 21] This is a diagram for explaining a method for setting a guide light irradiation restriction area according to the fourth embodiment. [Figure 22]This figure shows the guide light irradiation restriction region set by the guide light irradiation control unit of the fourth embodiment. [Figure 23] Figure 1 illustrates the control of guide light irradiation according to the fourth embodiment. [Figure 24] Figure 2 illustrates the control of guide light irradiation according to the fourth embodiment. [Figure 25] This figure shows a method for setting the guide light irradiation restriction area according to the first modified example. [Figure 26] This figure shows a method for setting the guide light irradiation restriction area according to a second modification. [Modes for carrying out the invention]

[0011] The following describes embodiments of the present invention based on the drawings.

[0012] [First Embodiment] (Configuration of X-ray imaging equipment) An X-ray imaging apparatus 100 according to a first embodiment of the present invention will be described with reference to Figures 1 to 13.

[0013] As shown in Figures 1 and 2, the X-ray imaging apparatus 100 comprises an X-ray irradiation unit 1 and an X-ray detection unit 2. The X-ray imaging apparatus 100 also includes a main unit 3 that supports the X-ray irradiation unit 1. The main unit 3 is equipped with multiple wheels 31 and is configured to be movable. The X-ray imaging apparatus 100 is a mobile X-ray imaging apparatus in which the entire apparatus (main unit 3) is movable. The X-ray imaging apparatus 100 is configured to be able to move to each patient room of a medical institution during rounds and take X-ray images of patients (subjects 900) lying on a bed 800.

[0014] The X-ray irradiation unit 1 irradiates the subject 900 with X-rays. The X-ray irradiation unit 1 also includes an X-ray tube 11, a collimator 12, and a gripping unit 13. The X-ray tube 11 irradiates X-rays when voltage is applied from a power supply (not shown). The collimator 12 adjusts the irradiation field (irradiation range) of the X-rays irradiated onto the subject 900. The gripping unit 13 is fixed to the collimator 12 and is used to grip the X-ray irradiation unit 1 when the position of the X-ray irradiation unit 1 is changed by a user such as a physician or radiologist.

[0015] The main body 3 of the device is configured as a trolley for the X-ray imaging apparatus 100, and contains a power supply unit, battery, etc. (not shown). The main body 3 is also provided with multiple wheels 31, a storage compartment 32, a support column 33, and an arm 34. The multiple wheels 31 are located at the bottom of the main body 3 to move it. The storage compartment 32 is located at the rear of the main body 3. The storage compartment 32 is configured to allow the X-ray detection unit 2 to be stored in a removable manner.

[0016] Furthermore, the support column 33 is attached to the front of the main body 3 of the device so as to extend vertically. The arm section 34 is attached so as to extend horizontally from the support column 33. The support column 33 is configured to rotate horizontally. The support column 33 is hollow inside, and components that allow the arm section 34 to move up and down are housed inside. The X-ray irradiation unit 1 is movably attached to the arm section 34. The arm section 34 is configured to move up and down relative to the support column 33 and to extend and retract so as to change the horizontal position of the X-ray irradiation unit 1. In other words, the X-ray irradiation unit 1 is configured to move up and down vertically in conjunction with the raising and lowering of the arm section 34, and is configured to move horizontally in conjunction with the horizontal rotation and extension and retraction of the arm section 34. The X-ray irradiation unit 1 is also attached to the arm section 34 so as to be able to change the X-ray irradiation angle.

[0017] In the X-ray imaging apparatus 100, when performing X-ray imaging on a subject 900, the user, such as a physician or radiographer, positions the X-ray detection unit 2 between the subject 900 and the examination table 800, and moves the X-ray irradiation unit 1. The X-ray irradiation unit 1 is positioned so that the direction of X-ray irradiation is perpendicular to the detection surface 2a of the X-ray detection unit 2, and is then positioned by the user so that the irradiation center of the X-rays to be irradiated is at the center of the detection surface 2a of the X-ray detection unit 2 (see Figure 3), which will be described later.

[0018] Furthermore, as shown in Figure 2, the main unit 3 of the device comprises a main unit control unit 35, a storage unit 36, a display operation unit 37, and a display 38. The main unit control unit 35 and the storage unit 36 ​​are housed inside the main unit 3 of the device.

[0019] The main unit control unit 35 controls X-ray imaging by controlling the X-ray irradiation unit 1 and the X-ray detection unit 2. The main unit control unit 35 is also configured to communicate with the X-ray detection unit 2 via a wireless connection such as a wireless LAN. The main unit control unit 35 then generates an X-ray image based on the detection signal of the X-rays detected by the X-ray detection unit 2. The main unit control unit 35 is a computer that includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory).

[0020] The storage unit 36 ​​is composed of a storage device such as a hard disk drive. The storage unit 36 ​​stores image data such as generated X-ray images. The storage unit 36 ​​is also configured to store various setting values ​​for operating the X-ray imaging device 100. Furthermore, the storage unit 36 ​​stores programs used for the control processing of the X-ray imaging device 100 by the main unit control unit 35.

[0021] The display operation unit 37 includes, for example, a touch panel type liquid crystal display. The display operation unit 37 is configured to function as a display unit that displays X-ray images generated by X-ray imaging and imaging order information, and as an input unit that receives various operations from a user such as a doctor or radiographer.

[0022] The X-ray detection unit 2 detects X-rays irradiated from the X-ray irradiation unit 1 and transmitted through the subject 900. As shown in Figure 2, the X-ray detection unit 2 includes a detector 21 and a detector cover 22 attached to the detector 21. A marker 22a is provided on the detector cover 22. The detector 21 includes, for example, an FPD (Flat Panel Detector). The detector 21 outputs a detection signal based on the detected X-rays. The detector 21 is configured as a wireless type X-ray detector and outputs the detection signal as a wireless signal. Specifically, the detector 21 is configured to communicate with the main unit control unit 35 via a wireless connection such as a wireless LAN, and outputs the detection signal as a wireless signal to the main unit control unit 35. The detector 21 and detector cover 22 that constitute the X-ray detection unit 2 are plate-shaped. The X-ray detection unit 2 is positioned between the subject 900 and the bed 800 on which the subject 900 lies during X-ray irradiation (X-ray imaging). Furthermore, the X-ray detection unit 2 has a detection surface 2a (see Figure 3) on the side where the X-rays are irradiated (the side of the X-ray irradiation unit 1).

[0023] Here, if the direction of X-ray irradiation deviates from the direction perpendicular to the detection surface 2a of the X-ray detection unit 2, the visibility of the generated X-ray image will decrease. Furthermore, when performing multiple X-ray imaging on a single subject 900, accuracy in the relative positioning (alignment) of the X-ray irradiation unit 1 and the X-ray detection unit 2 is required to maintain consistency in the generated X-ray images.

[0024] As shown in Figures 1 and 2, the X-ray imaging apparatus 100 includes a positioning assist unit 4. The positioning assist unit 4 has a positioning function for positioning the X-ray irradiation unit 1. The positioning assist unit 4 is attached to the X-ray irradiation unit 1. As shown in Figure 2, the positioning assist unit 4 includes a guide light irradiation unit 41, an optical camera 42, and a unit-side control unit 43. That is, the guide light irradiation unit 41 and the optical camera 42 are attached to the X-ray irradiation unit 1. The positioning assist unit 4 also includes a display 44. The positioning assist unit 4 is communicated with the main unit-side control unit 35. The positioning assist unit 4 is an example of the "positioning assist device for X-ray imaging apparatus" in the claims. The optical camera 42 and the unit-side control unit 43 are examples of the "region information acquisition unit" and "guide light irradiation control unit," respectively, in the claims.

[0025] The guide light irradiation unit 41 includes a laser light irradiation unit 41a and a laser light irradiation unit 41b. Note that the laser light irradiation unit 41a and the laser light irradiation unit 41b are examples of the "first laser light irradiation unit" and the "second laser light irradiation unit" as defined in the claims, respectively. The laser light irradiation units 41a and 41b irradiate laser light in a line shape. The laser light irradiation units 41a and 41b include a laser diode and a lens member that diffuses the laser light from the laser diode into a sheet-like (planar) shape. The laser light irradiation units 41a and 41b include, for example, a line laser module that irradiates a green line laser. This improves the visibility of the laser light compared to irradiating white laser light, allowing the user to easily see and understand the location where the laser light is irradiated.

[0026] <Detection of position and angle> The unit-side control unit 43 of the positioning assist unit 4 acquires the relative angular relationship between the detection surface 2a (see Figure 3) of the X-ray detection unit 2 and the X-ray irradiation direction of the X-ray irradiation unit 1. The unit-side control unit 43 also detects the relative positional relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2. Specifically, the unit-side control unit 43 acquires the relative position and angle between the X-ray irradiation unit 1 and the X-ray detection unit 2 by detecting the marker 22a provided on the X-ray detection unit 2 from the optical image 60 (see Figure 9) captured by the optical camera 42. Note that the X, Y, and Z directions in Figure 3 indicate directions relative to the X-ray detection unit 2.

[0027] As shown in Figure 3, the markers 22a are positioned at the corners of the detector cover 22 of the X-ray detection unit 2. For example, one marker 22a is provided at each of the two corners on the X1 direction side of the four corners of the X-ray detection unit 2. The markers 22a are provided separately from the X-ray detection unit 2 and are detachably positioned. The markers 22a are also rectangular in shape. The markers 22a are so-called AR markers, with information that can be acquired by imaging with the optical camera 42 pre-set. The X-ray detection unit 2 is positioned between the subject 900 and the bed 800 so that the markers 22a on the detector cover 22 are recognizable from the optical camera 42 side (Z1 direction side).

[0028] Furthermore, as shown in Figure 4, the laser beam irradiation units 41a and 41b of the guide light irradiation unit 41 are located in the unit housing 40 of the positioning auxiliary unit 4. Note that the U, V, and W directions in Figure 4 are directions relative to the X-ray irradiation unit 1. The laser beam irradiation unit 41a is located near the center of the opening in the V direction on the irradiation direction side (W2 direction side) of the unit housing 40 of the positioning auxiliary unit 4, on the U2 direction side. The laser beam irradiation unit 41b is located adjacent to the optical camera 42 near the center of the opening in the U direction on the irradiation direction side (W2 direction side) of the unit housing 40 of the positioning auxiliary unit 4, on the V2 direction side.

[0029] Furthermore, in the collimator 12 of the X-ray irradiation unit 1, the unit housing 40 of the positioning auxiliary unit 4 is positioned on the irradiation direction side (subject 900 side, W2 direction side) where the X-rays are irradiated. The unit housing 40 is provided with a rectangular opening through which the irradiated X-rays pass on the irradiation direction side of the collimator 12. This opening has a rectangular shape with its sides aligned in the U and V directions on the irradiation direction side of the unit housing 40. The optical camera 42 and the unit-side control unit 43 are located in the unit housing 40.

[0030] Furthermore, the optical camera 42 acquires an optical image 60 (see Figure 9) for acquiring the guide light irradiation area 70 illuminated by the guide light irradiation unit 41. The optical camera 42 includes, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. Note that the optical image 60 is an example of the "area acquisition information" in the claims.

[0031] As shown in Figure 4, the optical camera 42 is positioned near the center in the U direction on the V2 direction side of the opening portion of the unit housing portion 40 of the positioning auxiliary unit 4, on the irradiation direction side (W2 direction side). The optical camera 42 optically images the subject 900 side (W2 direction side) along the X-ray irradiation direction from the X-ray irradiation unit 1 side. The optical camera 42 optically images the marker 22a in order to detect the three-dimensional arrangement (position and angle) of the X-ray detection unit 2. The optical camera 42 captures an optical image 60 as a moving image and outputs the optical image 60 to the unit-side control unit 43.

[0032] The unit-side control unit 43 controls each part of the positioning assist unit 4. The unit-side control unit 43 controls imaging by the optical camera 42, illumination of guide light 50 (see Figure 6) by the guide light irradiation unit 41 (described later), and display of the display 44. The unit-side control unit 43 also controls the display of the display 38. Furthermore, the unit-side control unit 43 is a computer composed of, for example, a CPU, ROM, RAM, and a storage device such as flash memory.

[0033] Specifically, the unit-side control unit 43 detects the relative positional relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2, and the relative angular relationship between the detection surface 2a of the X-ray detection unit 2 and the X-ray irradiation direction (W2 direction) of the X-ray irradiation unit 1, based on the marker 22a captured by the optical camera 42. More specifically, the unit-side control unit 43 acquires three-dimensional positional and angular information of the marker 22a in the optical image 60 by detecting the marker 22a from the optical image 60 captured by the optical camera 42. The unit-side control unit 43 also pre-stores information such as the size and shape of the marker 22a, information indicating the positional relationship of the marker 22a with respect to the X-ray detection unit 2, and information indicating the positional relationship of the optical camera 42 with respect to the X-ray irradiation unit 1 as parameters for detection processing. The unit-side control unit 43 is configured to detect the relative positional and angular relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2 based on the positional information of the marker 22a detected in the optical image 60 and the pre-stored parameters for detection processing.

[0034] As shown in Figure 4, a display 44 is provided on the side of the unit housing 40 of the positioning auxiliary unit 4 on the V2 direction side. The display 44 displays the SID (Source to image receptor distance) by the unit-side control unit 43. Specifically, the unit-side control unit 43 calculates the SID based on the three-dimensional positional relationship between the detected X-ray irradiation unit 1 and the X-ray detection unit 2. The unit-side control unit 43 then displays the calculated SID value on the display 44. The display 44 is, for example, an organic EL display.

[0035] Furthermore, the X-ray imaging apparatus 100 is equipped with a display 38 in addition to the display 44. The display 38 is located above the collimator 12 of the X-ray irradiation unit 1 (on the W1 direction side). The display 38 is, for example, a liquid crystal display. The display 38 is connected to the unit-side control unit 43 via a cable (not shown).

[0036] The unit-side control unit 43 displays the optical image 60 captured by the optical camera 42, the specific numerical values ​​of the detected angle relationship deviations (roll angle deviation and pitch angle deviation), and the SID value on the display 38. The unit-side control unit 43 also displays the optical image 60 captured by the optical camera 42 on the display 38. Based on the position information of the marker 22a detected in the optical image 60, the unit-side control unit 43 calculates the region in which X-rays are detected by the X-ray detection unit 2. The unit-side control unit 43 then displays the X-ray detection region on the detection surface 2a of the X-ray detection unit 2 superimposed on the optical image 60. The X-ray detection region is displayed, for example, as a frame line surrounding the X-ray detection region.

[0037] Furthermore, the unit housing portion 40 (see Figure 4) of the positioning assist unit 4 is configured to be attachable (retrofittable) to the X-ray irradiation unit 1. In other words, the positioning assist unit 4 is configured to be retrofittable to an existing X-ray imaging device 100. Similarly, the display 38 is configured to be attachable (retrofittable) to the X-ray irradiation unit 1, just like the positioning assist unit 4.

[0038] The unit-side control unit 43 is configured to detect the three-dimensional positional relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2. As shown in Figure 5, the unit-side control unit 43 is configured to detect the relative positional relationship of the X-ray detection unit 2 (detection surface 2a) with respect to the X-ray tube 11, which is the X-ray focal point, in each of the three axial directions: the vertical axis direction (X direction), the horizontal axis direction (Y direction), and the orthogonal direction perpendicular to the detection surface 2a (Z direction).

[0039] Furthermore, the unit-side control unit 43 detects the relative angular relationship between the X-ray irradiation direction (W2 direction) of the X-ray irradiation unit 1 and the detection surface 2a of the X-ray detection unit 2 in each of the three rotational angular directions. For example, the unit-side control unit 43 is configured to detect the relative angular relationship in each of the following directions: the roll angle direction (φ direction) with the vertical axis direction (X direction) of the detection surface 2a as the axis of rotation, the pitch angle direction (θ direction) with the horizontal axis direction (Y direction) as the axis of rotation, and the yaw angle direction (ψ direction) with the orthogonal direction (Z direction) as the axis of rotation.

[0040] The positioning assistance unit 4, via the unit-side control unit 43, acquires the three-dimensional arrangement (position and angle) of the X-ray detection unit 2 relative to the X-ray irradiation unit 1. Then, as shown in Figure 6, the guide light irradiation unit 41 projects guide light 50 onto the body surface of the subject 900 to assist in the alignment (positioning) of the X-ray irradiation unit 1.

[0041] In the first embodiment, as shown in Figure 6, the guide light irradiation unit 41 is configured to irradiate guide light 50 that indicates the center position (X-ray irradiation center) of the X-ray irradiation area irradiated by the X-ray irradiation unit 1. Specifically, the laser light irradiation unit 41a irradiates laser light 51 in a line along the U direction. The laser light irradiation unit 41b irradiates laser light 52 in a line along the V direction, which intersects the U direction. The laser light irradiation units 41a and 41b are configured to irradiate laser light such that the laser light (laser light 51 and 52) emitted from each intersects at the center position of the X-ray irradiation area. The laser light irradiation units 41a and 41b of the guide light irradiation unit 41 project mutually orthogonal line-shaped laser light 51 and 52 onto the subject 900, thereby irradiating (projecting) a cross-shaped guide light 50 onto the subject 900. The intersection point of the laser light 51 and laser light 52 indicates the position of the X-ray irradiation center irradiated from the X-ray irradiation unit 1. The guide light irradiation unit 41 (laser light irradiation units 41a and 41b) is configured to irradiate guide light 50 based on a control signal from the unit-side control unit 43. The U direction and V direction are examples of the "first direction" and "second direction" in the claims, respectively.

[0042] Then, as shown in Figure 7, the optical camera 42 captures an optical image 60 showing the X-ray detection unit 2 and the subject 900. The unit-side control unit 43 is configured to acquire the guide light irradiation area 70 (see Figure 9) based on the optical image 60 captured by the optical camera 42.

[0043] In the first embodiment, the unit-side control unit 43 is configured to acquire the relative positional relationship between the X-ray irradiation unit 1 to which the guide light irradiation unit 41 is attached and the X-ray detection unit 2 based on the optical image 60 captured by the optical camera 42, and to acquire the guide light irradiation area 70 based on the acquired relative positional relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2.

[0044] The unit-side control unit 43 geometrically calculates the guide light irradiation area 70 based on processing using the position information of the marker 22a as described above. Specifically, as shown in Figure 8, the unit-side control unit 43 acquires the distance D1 between the X-ray irradiation unit 1 (X-ray tube 11) and the X-ray detection unit 2, the angle θ between the X-ray irradiation direction and the detection surface 2a of the X-ray detection unit 2, and the amount of displacement M in the height direction between the center position 11a of the X-ray irradiation unit 1 (X-ray tube 11) and the center position 2b of the X-ray detection unit 2. Based on the acquired distance D1, angle θ, and displacement M, and the aperture (numerical aperture) of the guide light 50 from the guide light irradiation unit 41, the unit-side control unit 43 calculates the guide light irradiation area 70 (see Figure 9).

[0045] (Guide light irradiation control) The positioning assist unit 4 has a guide light irradiation control function that stops the irradiation of guide light 50 when the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80 (see Figure 10). In the first embodiment, when the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80, the unit-side control unit 43 of the positioning assist unit 4 stops the irradiation of guide light 50. The guide light irradiation control function is configured to be switchable between an ON state and an OFF state in response to the imaging area and user operation.

[0046] In the first embodiment, as shown in Figures 9 and 10, the positioning assist unit 4 switches the guide light irradiation control function to the ON state when the chest 903 or other area is set as the X-ray imaging site, where there is a high possibility that the guide light 50 will be irradiated onto the face 901 (eyes 902) of the subject 900 during positioning.

[0047] Furthermore, the unit-side control unit 43 is configured to set a guide light irradiation restriction region 80 (the region shown by hatching in Figure 10) that includes an area overlapping with at least the eye 902 of the subject 900, and to control the irradiation of guide light 50 by the guide light irradiation unit 41 based on the set guide light irradiation restriction region 80.

[0048] Furthermore, the unit-side control unit 43 is configured to stop the irradiation of the guide light 50 when the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80.

[0049] The unit-side control unit 43 detects the position of a specific body part located above the chest 903 of the subject 900 in the optical image 60 (see Figure 9) captured by the optical camera 42. In the first embodiment, the unit-side control unit 43 detects the position of the shoulder 904 of the subject 900 in the optical image 60 captured by the optical camera 42.

[0050] Specifically, the unit-side control unit 43 acquires the body contour of the subject 900 from the optical image 60 captured by the optical camera 42, and detects the position of the subject 900's shoulder 904 from the acquired body contour.

[0051] Then, the unit-side control unit 43 sets a region that includes at least the area overlapping with the eye 902 of the subject 900, based on the position of the detected specific area (shoulder 904 of the subject 900), as the guide light irradiation restriction region 80.

[0052] Specifically, as shown in Figure 10, the unit-side control unit 43 sets the area on the head side 905 of the subject 900, beyond the position of the shoulder 904, as the guide light irradiation restriction area 80. That is, the unit-side control unit 43 sets the guide light irradiation restriction area 80 to include the area overlapping with the position of the face 901 of the subject 900. Furthermore, the unit-side control unit 43 sets the width of the guide light irradiation restriction area 80 in the left-right direction (Y direction) to be wider than that of the X-ray detection unit 2. In the first embodiment, the unit-side control unit 43 sets the entire area in the optical image 60 located on the head side (above) of the detected specific area (shoulder 904 of the subject 900) as the guide light irradiation restriction area 80. Then, the unit-side control unit 43 controls the irradiation of the guide light 50 based on the guide light irradiation restriction area 80, thereby suppressing the irradiation of the guide light 50 to the eye 902 of the subject 900. This suppresses the possibility of causing discomfort to the subject 900 due to the guide light 50 irradiating the subject 900's eyes 902.

[0053] Furthermore, an image showing the guide light irradiation restriction area 80 superimposed on the optical image 60, as shown in Figure 10, is displayed on the display 38 (see Figure 4). Note that the guide light irradiation restriction area 80 set by the unit-side control unit 43 may not be displayed on the display 38, but may be an area used only in the processing within the unit-side control unit 43.

[0054] The unit-side control unit 43 acquires a guide light irradiation area 70 that includes the irradiation areas of the laser light (laser light 51 and 52) irradiated from the laser light irradiation unit 41a and the laser light irradiation unit 41b, respectively. In the first embodiment, the unit-side control unit 43 acquires a guide light irradiation area 70 that includes guide light irradiation areas 70a and 70b corresponding to the laser light 51 and 52, respectively.

[0055] The unit-side control unit 43 then controls the irradiation of the guide light 50 to stop if the guide light irradiation area 70 acquired based on the optical image 60 overlaps with the set guide light irradiation restriction area 80. In the first embodiment, the unit-side control unit 43 is configured to control the irradiation of the guide light 50 to stop if the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80 which includes an area that overlaps with the position of the face 901 of the subject 900.

[0056] As shown in Figure 11, when the unit-side control unit 43 does not control the irradiation of the guide light 50 based on the guide light irradiation area 70 and the guide light irradiation restriction area 80 (when the guide light irradiation control function is OFF), the guide light irradiation area 70 may overlap with the face 901 of the subject 900. In other words, the guide light 50 may be irradiated onto the face 901 and eyes 902 of the subject 900.

[0057] In the first embodiment, when the guide light irradiation control function is ON, as shown in Figure 12, if the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80 during the alignment of the X-ray irradiation unit 1 during X-ray imaging, the irradiation of the guide light 50 is stopped by the control of the unit-side control unit 43 (see Figure 13). Specifically, when the irradiation of the guide light 50 is started for the alignment of the X-ray irradiation unit 1 during X-ray imaging, or when the X-ray irradiation unit 1 is moved for the alignment of the X-ray irradiation unit 1 during X-ray imaging, if at least a part of the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80, the irradiation of the guide light 50 is stopped by the control of the unit-side control unit 43.

[0058] In the first embodiment, the unit-side control unit 43 is configured to stop the irradiation of laser light (laser light 51 and 52) from the laser light irradiation unit 41a and the laser light irradiation unit 41b if at least one of the irradiation areas of the laser light (laser light 51 and 52) irradiated from each of the laser light irradiation unit 41a and the laser light irradiation unit 41b overlaps with the guide light irradiation limiting area 80.

[0059] In other words, if the laser light (laser light 51 or 52) emitted from either the laser light irradiation unit 41a or 41b overlaps with the guide light irradiation restriction area 80, the irradiation of laser light from both the laser light irradiation unit 41a and the laser light irradiation unit 41b is stopped. This prevents the guide light 50 from being irradiated onto the face 901 of the subject 900. The control described above for setting the guide light irradiation restriction area 80, and the control for stopping the irradiation of the guide light 50 when the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80, may be performed in real time or at predetermined time intervals.

[0060] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0061] In the first embodiment, when the guide light irradiation area 70 overlaps with the guide light irradiation restriction area 80, which includes an area overlapping with at least the eye 902 of the subject 900, the unit-side control unit 43 (guide light irradiation control unit) controls the irradiation of the guide light 50 to stop in at least the portion overlapping with the guide light irradiation restriction area 80. As a result, even if the user does not perform an operation to stop the irradiation of the guide light 50, if the guide light 50 is irradiated into an area overlapping with the eye 902 of the subject 900, the irradiation of the guide light 50 is stopped by the control of the unit-side control unit 43. As a result, it is possible to suppress the discomfort caused to the subject 900 due to the irradiation of the guide light 50, which has a relatively high light intensity, towards the eye 902 of the subject 900. This makes it possible to provide an X-ray imaging apparatus 100 and a positioning assist unit 4 (positioning assist device for X-ray imaging apparatus) that can suppress discomfort to the subject 900 during positioning of the X-ray irradiation unit 1, caused by the relatively high-intensity guide light 50 that is emitted when positioning the X-ray irradiation unit 1 during X-ray imaging.

[0062] Furthermore, the X-ray imaging apparatus 100 according to the first embodiment described above can be configured as follows to obtain the following additional effects.

[0063] Furthermore, in the X-ray imaging apparatus 100 according to the first embodiment, the unit-side control unit 43 (guide light irradiation control unit) sets a guide light irradiation restriction area 80 that includes an area overlapping with the position of the face 901 of the subject 900, and controls the irradiation of the guide light 50 when the guide light irradiation area 70 overlaps with the set guide light irradiation restriction area 80. As a result, the guide light irradiation restriction area 80 can be set wider than when the guide light irradiation restriction area 80 is set only in the position overlapping with the eye 902 of the subject 900. Consequently, even if the subject 900 moves during positioning in X-ray imaging, the irradiation of the guide light 50 towards the eye 902 of the subject 900 can be effectively suppressed.

[0064] Furthermore, in the X-ray imaging apparatus 100 according to the first embodiment, the unit-side control unit 43 (guide light irradiation control unit) acquires the guide light irradiation area 70 based on the optical image 60 captured by the optical camera 42. The guide light irradiation unit 41 and the optical camera 42 are attached to the X-ray irradiation unit 1. The unit-side control unit 43 (guide light irradiation control unit) then acquires the relative positional relationship between the X-ray irradiation unit 1 to which the guide light irradiation unit 41 is attached and the X-ray detection unit 2 based on the optical image 60 captured by the optical camera 42, and acquires the guide light irradiation area 70 based on the acquired relative positional relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2. Thus, unlike the case where the guide light irradiation area 70 is acquired based on the relative positional relationship between the optical camera 42 (positioning assistance unit 4) acquired using a magnetic sensor or the like and the X-ray detection unit 2, the unit-side control unit 43 is not affected by the surrounding magnetic field when acquiring the guide light irradiation area 70. As a result, the unit-side control unit 43 can accurately acquire the guide light irradiation area 70 regardless of the influence of the surrounding magnetic field.

[0065] Furthermore, in the X-ray imaging apparatus 100 according to the first embodiment, the unit-side control unit 43 (guide light irradiation control unit) sets the guide light irradiation restriction area 80 based on the optical image 60 captured by the optical camera 42. The unit-side control unit 43 then controls the irradiation of the guide light 50 to stop when the guide light irradiation area 70 acquired based on the optical image 60 overlaps with the set guide light irradiation restriction area 80. This prevents the guide light 50 from being irradiated into the guide light irradiation restriction area 80 set based on the optical image 60. In addition, unlike the case where the guide light irradiation restriction area 80 is set based on the relative positional relationship between the optical camera 42 (positioning assistance unit 4) and the X-ray detection unit 2 acquired using a magnetic sensor or the like, the unit-side control unit 43 is not affected by the surrounding magnetic field when setting the guide light irradiation restriction area 80. As a result, the unit-side control unit 43 can set the guide light irradiation restriction area 80 with high accuracy regardless of the influence of the surrounding magnetic field.

[0066] Furthermore, in the X-ray imaging apparatus 100 according to the first embodiment, the unit-side control unit 43 (guide light irradiation control unit) detects the position of the subject 900's shoulder 904 (specific area) located above the chest 903 of the subject 900 in the optical image 60 captured by the optical camera 42. The unit-side control unit 43 is configured to set a guide light irradiation restriction area 80, which includes an area overlapping with at least the position of the subject 900's eye 902, based on the detected position of the subject 900's shoulder 904 (specific area). This makes it possible to suppress the irradiation of guide light 50 within the guide light irradiation restriction area 80 set based on the position of the subject 900's shoulder 904 (specific area). In addition, since the guide light irradiation restriction area 80 is set by detecting the subject 900's shoulder 904, it is easier for the unit-side control unit 43 to set the guide light irradiation restriction area 80 compared to the case where the guide light irradiation restriction area 80 is set by detecting the eye 902, which is smaller than the shoulder 904.

[0067] Furthermore, in the X-ray imaging apparatus 100 according to the first embodiment, the laser light irradiation unit 41a (first laser light irradiation unit) and the laser light irradiation unit 41b (second laser light irradiation unit) irradiate laser light such that the laser light (laser light 51 and 52) emitted from each unit intersects at the center of the X-ray irradiation area. The unit-side control unit 43 (guide light irradiation control unit) acquires a guide light irradiation area 70 that includes the irradiation areas of the laser light (laser light 51 and 52) emitted from each of the laser light irradiation units 41a and 41b. As a result, the unit-side control unit 43 can control the irradiation of the laser light emitted from each of the laser light irradiation units 41a and 41b based on the guide light irradiation restriction area 80 and the guide light irradiation area 70 that includes the irradiation areas of the laser light emitted from each of the laser light irradiation units 41a and 41b (guide light irradiation areas 70a and 70b). As a result, unlike when the irradiation area of ​​only one of the laser beams irradiated from each of the laser beam irradiation units 41a and 41b is acquired as the guide light irradiation area 70, it is possible to suppress the irradiation of an area overlapping the position of the subject 900's eyes 902 with either the laser beam 51 irradiated from the laser beam irradiation unit 41a or the laser beam 52 irradiated from the laser beam irradiation unit 41b.

[0068] Furthermore, in the X-ray imaging apparatus 100 according to the first embodiment, the unit-side control unit 43 (guide light irradiation control unit) controls the irradiation of laser light (laser light 51 and 52) from the laser light irradiation unit 41a (first laser light irradiation unit) and the laser light irradiation unit 41b (second laser light irradiation unit) if at least one of the irradiation areas of the laser light (laser light 51 and 52) irradiated from each of them overlaps with the guide light irradiation restriction area 80. This prevents the laser light irradiated from each of the laser light irradiation units 41a and 41b from irradiating into the guide light irradiation restriction area 80. As a result, it is possible to prevent the laser light irradiated from each of the laser light irradiation units 41a and 41b from irradiating into an area that overlaps with the position of the eyes 902 of the subject 900.

[0069] Furthermore, the X-ray imaging apparatus 100 according to the first embodiment includes a mobile type apparatus body 3 that supports the X-ray irradiation unit 1 and is equipped with a plurality of wheels 31 to make it movable. This makes it possible to suppress discomfort to the patient 900 caused by the relatively high-intensity guide light 50 that is emitted when positioning the X-ray irradiation unit 1 during X-ray imaging in mobile examinations.

[0070] [Second Embodiment] The setting of the guide light irradiation limiting region 280 according to the second embodiment will be described with reference to Figures 14 to 17. In the figures, parts with the same configuration as in the first embodiment are denoted by the same reference numerals.

[0071] Unlike the first embodiment, in order to acquire the guide light irradiation restriction area 280, the unit-side control unit 43 is configured to acquire the position of the X-ray detection unit 2 based on the optical image 60 captured by the optical camera 42. The unit-side control unit 43 is then configured to set the area including the area on the head 905 side of the subject 900 relative to the X-ray detection unit 2 as the guide light irradiation restriction area 280 based on the acquired position of the X-ray detection unit 2.

[0072] In the second embodiment, as shown in Figure 14, the unit-side control unit 43 acquires the position of the end 2c of the X-ray detection unit 2 based on the distance D2 between the center position 2b of the X-ray detection unit 2 and the end 2c of the X-ray detection unit 2. As shown in Figure 15, the unit-side control unit 43 acquires the position of the end 2c of the X-ray detection unit 2 on the head 905 side of the subject 900 based on the optical image 60, and sets the area on the head 905 side of the subject 900, which is further from the end 2c of the X-ray detection unit 2, as the guide light irradiation restriction area 280 (the area shown by hatching in Figure 16).

[0073] Furthermore, the unit-side control unit 43, similar to the first embodiment, acquires the relative positional relationship between the X-ray irradiation unit 1 to which the guide light irradiation unit 41 is attached and the X-ray detection unit 2 based on the optical image 60 captured by the optical camera 42. Then, the unit-side control unit 43 acquires the guide light irradiation area 70 (see Figure 16) based on the acquired relative positional relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2.

[0074] Then, similar to the first embodiment, the control of the irradiation of guide light 50 by the guide light irradiation unit 41 is performed by the unit-side control unit 43 based on the guide light irradiation area 70 and the guide light irradiation restriction area 280. As a result, when the guide light irradiation area 70 acquired based on the optical image 60 overlaps with the guide light irradiation restriction area 280 during X-ray imaging alignment, the irradiation of guide light 50 is stopped by the control of the unit-side control unit 43 (see Figure 17).

[0075] The other configurations of the second embodiment are the same as those of the first embodiment described above.

[0076] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0077] In the second embodiment, similar to the first embodiment, it is possible to suppress causing discomfort to the subject 900 during the positioning of the X-ray irradiation unit 1, due to the guide light 50 with relatively high light intensity that is emitted when positioning the X-ray irradiation unit 1 during X-ray imaging.

[0078] Furthermore, in the second embodiment described above, the following additional effects can be obtained by configuring it as follows.

[0079] In the second embodiment, the unit-side control unit 43 acquires the position of the X-ray detection unit 2 based on the optical image 60 captured by the optical camera 42. Based on the acquired position of the X-ray detection unit 2, the unit-side control unit 43 sets the area including the area on the head 905 side of the subject 900 relative to the X-ray detection unit 2 as the guide light irradiation restriction area 280. This makes it possible to suppress the irradiation of the guide light 50 to the area on the head 905 side of the subject 900 relative to the X-ray detection unit 2. As a result, when the X-ray detection unit 2 is positioned so as to overlap with a part of the subject 900 other than the head 905, such as when imaging the chest 903, it is possible to suppress the irradiation of the guide light 50 to the eyes 902 of the subject 900.

[0080] Furthermore, the other effects of the second embodiment are the same as those of the first embodiment described above.

[0081] [Third Embodiment] The control of the irradiation of the guide light 50 according to the third embodiment will be described with reference to Figure 18. In the figure, parts with the same configuration as those in the first and second embodiments are denoted by the same reference numerals.

[0082] In the third embodiment, the unit-side control unit 43 controls the irradiation of guide light 50 to stop in the portion that overlaps with the guide light irradiation limiting region 80 (the region shown by hatching in Figure 18) when the guide light irradiation region 70 overlaps with the guide light irradiation limiting region 80.

[0083] The unit-side control unit 43 controls the irradiation of laser light from one of the laser light irradiation units 41a and 41b to stop if at least one of the irradiation areas of the laser light (laser light 51 and 52) irradiated from each of the laser light irradiation units 41a and 41b overlaps with the guide light irradiation limiting area 80.

[0084] Specifically, the unit-side control unit 43 is configured to stop the irradiation of the laser beam 51 emitted from the laser beam irradiation unit 41a if the laser beam 51 emitted from the laser beam irradiation unit 41a overlaps with the guide light irradiation limiting region 80, as shown in Figure 18. Furthermore, the unit-side control unit 43 stops the irradiation of the laser beam 52 emitted from the laser beam irradiation unit 41b if the laser beam 52 emitted from the laser beam irradiation unit 41b overlaps with the guide light irradiation limiting region 80.

[0085] The other configurations of the third embodiment are the same as those of the first and second embodiments described above.

[0086] (Effects of the third embodiment) In the third embodiment, the following effects can be obtained.

[0087] In the third embodiment, similar to the first and second embodiments, it is possible to suppress causing discomfort to the subject 900 during the positioning of the X-ray irradiation unit 1, due to the relatively high-intensity guide light 50 that is emitted when positioning the X-ray irradiation unit 1 during X-ray imaging.

[0088] Furthermore, in the third embodiment described above, the following additional effects can be obtained by configuring it as follows.

[0089] Furthermore, in the third embodiment, the unit-side control unit 43 controls the irradiation of the laser beam (laser beams 51 and 52) emitted from each of the laser beam irradiation units 41a and 41b to stop the irradiation of the laser beam emitted from one of the laser beam irradiation units 41a and 41b if at least one of the irradiation areas overlaps with the guide light irradiation restriction area 80. This prevents the laser beam emitted from each of the laser beam irradiation units 41a and 41b from being irradiated into the guide light irradiation restriction area 80. As a result, it is possible to prevent the laser beam emitted from each of the laser beam irradiation units 41a and 41b from being irradiated into an area that overlaps with the position of the eyes 902 of the subject 900. In addition, among the laser beams emitted from each of the laser beam irradiation units 41a and 41b, only the irradiation of the laser beam that overlaps with the guide light irradiation restriction area 80 is stopped. As a result, among the laser beams emitted from each of the laser beam irradiation units 41a and 41b, the irradiation of laser beams that do not overlap with the guide light irradiation restriction area 80 is not stopped. Consequently, positioning during X-ray imaging can be made easier compared to the case where the irradiation of laser beams emitted from both of the laser beam irradiation units 41a and 41b is stopped.

[0090] Furthermore, the other effects of the third embodiment are the same as those of the first and second embodiments described above.

[0091] [Fourth Embodiment] The configuration of the X-ray imaging apparatus 400 according to the fourth embodiment will be described with reference to Figures 19 to 24. In the figures, parts with the same configuration as in the first embodiment are denoted by the same reference numerals.

[0092] In the X-ray imaging apparatus 400 of the fourth embodiment, the guide light irradiation unit 441 (see Figure 19) irradiates guide light 450 (see Figure 20) that indicates the X-ray irradiation area to be irradiated by the X-ray irradiation unit 1. The guide light irradiation unit 441 includes, for example, a halogen lamp. The guide light irradiation unit 441 is also provided within the X-ray irradiation unit 1. The irradiation area of ​​the guide light 450 irradiated from the guide light irradiation unit 441 is adjusted by the collimator 12, similar to the X-rays irradiated from the X-ray tube 11. Therefore, the irradiation area of ​​the guide light 450 corresponds to the X-ray irradiation area. The guide light 450 is irradiated in a substantially rectangular shape.

[0093] In the fourth embodiment, guide light 450 is emitted in such a way that a cross-shaped shadow is created to indicate the position of the irradiation center of the X-rays emitted from the X-ray irradiation unit 1. The intersection of the cross-shaped shadow indicates the position of the irradiation center of the X-rays emitted from the X-ray irradiation unit 1. Note that the cross-shaped shadow is omitted in Figures 21 to 24.

[0094] The control of the irradiation of guide light 450 by the guide light irradiation unit 441 is performed by the main unit control unit 35. The unit-side control unit 43 is connected to the main unit control unit 35 for communication. The unit-side control unit 43 controls the irradiation of guide light 450 by the guide light irradiation unit 441 based on the guide light irradiation area 470 (see Figure 21) and the guide light irradiation restriction area 80 (area shown by hatching in Figure 22) via the main unit control unit 35. The main unit control unit 35 and the unit-side control unit 43 may be configured as a single unit. Furthermore, the X-ray irradiation unit 1 and the positioning assist unit 4 of the X-ray imaging apparatus 400 may be configured as a single unit.

[0095] Furthermore, the unit-side control unit 43 is configured to stop the irradiation of guide light 450 emitted from the guide light irradiation unit 41 when the guide light irradiation area 470 overlaps with the guide light irradiation restriction area 80.

[0096] The unit-side control unit 43 acquires a guide light irradiation area 470 that includes the irradiation area of ​​the guide light 450 irradiated from the guide light irradiation unit 441.

[0097] Furthermore, the unit-side control unit 43, similar to the first embodiment, acquires the body contour of the subject 900 from the optical image 60 captured by the optical camera 42, and detects the position of the subject 900's shoulder 904 (see Figure 21) from the acquired body contour of the subject 900.

[0098] As shown in Figure 22, the unit-side control unit 43 sets a region that includes at least the area overlapping the position of the eye 902 of the subject 900, based on the detected position of the shoulder 904 of the subject 900, as the guide light irradiation restriction region 80.

[0099] The unit-side control unit 43 then controls the irradiation of the guide light 450 to stop if the guide light irradiation area 470 acquired based on the optical image 60 overlaps with the set guide light irradiation restriction area 80. The unit-side control unit 43 also controls the irradiation of the guide light 450 to stop if the guide light irradiation area 470 overlaps with the guide light irradiation restriction area 80, which includes an area that overlaps with the position of the face 901 of the subject 900.

[0100] As shown in Figure 23, the unit-side control unit 43 is configured to stop the irradiation of guide light 450 emitted from the guide light irradiation unit 441 when the guide light irradiation area 470 overlaps with the guide light irradiation restriction area 80. As a result, when aligning X-ray imaging, if the guide light irradiation area 470 overlaps with the guide light irradiation restriction area 80, the irradiation of guide light 450 is stopped (see Figure 24).

[0101] The other configurations of the fourth embodiment are the same as those of the first to third embodiments described above.

[0102] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0103] The X-ray imaging apparatus 400 according to the fourth embodiment, like the first to third embodiments described above, can suppress causing discomfort to the subject 900 during the positioning of the X-ray irradiation unit 1 due to the relatively high light intensity guide light 450 that is emitted when positioning the X-ray irradiation unit 1 during X-ray imaging.

[0104] Furthermore, the other effects of the fourth embodiment are the same as those of the first to third embodiments described above.

[0105] Furthermore, two or more embodiments from the first to fourth embodiments may be combined.

[0106] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0107] For example, in the first to fourth embodiments described above, the unit-side control unit 43 (guide light irradiation control unit) is shown to stop the irradiation of guide light 50 or 450 when the guide light irradiation area 70 overlaps with a guide light irradiation restriction area 80 or 280 that includes an area overlapping with at least the eye 902 of the subject 900, but the present invention is not limited thereto. In the present invention, the guide light irradiation control unit may be configured to reduce the light intensity of the guide light irradiated from the guide light irradiation unit when the guide light irradiation area overlaps with a guide light irradiation restriction area that includes an area overlapping with at least the eye of the subject. In this case, when the guide light irradiation area overlaps with a guide light irradiation restriction area that includes an area overlapping with at least the eye of the subject, the light intensity of the guide light is reduced, so that the discomfort caused when the guide light is irradiated towards the subject's eyes can be reduced compared to when the light intensity of the guide light is not reduced. As a result, it is possible to suppress the discomfort caused to the subject due to the irradiation of relatively high-intensity guide light towards the subject's eyes. This makes it possible to suppress discomfort to the subject during the positioning of the X-ray irradiation unit 1, which is caused by relatively high-intensity guide light emitted when positioning the X-ray irradiation unit 1 during X-ray imaging.

[0108] Furthermore, in the first to fourth embodiments described above, examples were shown in which the entire region of the optical image 60 located above (towards the head) the position of the shoulder 904 of the subject 900 detected from the optical image 60, or the entire region of the optical image 60 located above (towards the head) the position of the end 2c of the X-ray detection unit 2, are set as the guide light irradiation restriction region 80 or 280, respectively, but the present invention is not limited thereto. In the present invention, as shown in the first modified example in Figure 25, the guide light irradiation restriction region 580 (the region shown by hatching in Figure 25) may be set in the vertical direction (X direction) for a predetermined width. In this case, the guide light irradiation restriction region 580 may be set in correspondence with the subject 900. For example, the region set as the guide light irradiation restriction region 580 may be changed in correspondence with the gender and age of the subject 900. Also, as shown in the second modified example in Figure 26, the guide light irradiation restriction region 680 (the region shown by hatching in Figure 26) may be set in the horizontal direction (Y direction) for a predetermined width. For example, the width of the guide light irradiation restriction area 680 in the left-right direction (Y direction) may be set based on the position of the marker 22a. Also, the width of the guide light irradiation restriction area 680 in the up-down direction (X direction) may be set based on the position of the marker 22a. Furthermore, the method for setting the guide light irradiation restriction area by the guide light irradiation control unit may be a combination of the methods described in each of the first to fourth embodiments, the first modification, and the second modification. Furthermore, the guide light irradiation control unit may be configured to switch the method for setting the guide light irradiation restriction area to the methods described in each of the first to fourth embodiments, the first modification, and the second modification.

[0109] Furthermore, in the first to fourth embodiments described above, an example was shown in which the unit-side control unit 43 is set as a guide light irradiation restriction area 80 that includes an area overlapping with the position of the face 901 of the subject 900, but the present invention is not limited thereto. In the present invention, the guide light irradiation control unit may detect the position of the subject's eyes from the optical image and set the area overlapping with the subject's eyes as the guide light irradiation restriction area. When the guide light irradiation area overlaps with the area overlapping with the subject's eyes, the guide light irradiation control unit may perform control to stop the irradiation of guide light in at least the portion overlapping with the area overlapping with the subject's eyes, or control to reduce the light intensity of the guide light irradiated from the guide light irradiation unit.

[0110] Furthermore, in the first to fourth embodiments described above, the unit-side control unit 43 (guide light irradiation control unit) acquires the relative positional relationship between the X-ray irradiation unit 1 to which the guide light irradiation unit 41 is attached and the X-ray detection unit 2 based on the optical image 60 captured by the optical camera 42, and acquires the guide light irradiation area 70 based on the acquired relative positional relationship between the X-ray irradiation unit 1 and the X-ray detection unit 2. However, the present invention is not limited to this. In the present invention, the guide light irradiation control unit may also acquire (detect) the guide light irradiation area by detecting the guide light reflected in the optical image.

[0111] Furthermore, in the first to fourth embodiments described above, an example was shown in which the unit-side control unit 43 acquires the guide light irradiation area 70 based on the optical image 60, but the present invention is not limited thereto. In the present invention, the guide light irradiation control unit may acquire the relative positional relationship between the X-ray irradiation unit to which the guide light irradiation unit is attached and the X-ray detection unit using a magnetic sensor, and acquire the guide light irradiation area 70 based on the acquired relative positional relationship between the X-ray irradiation unit and the X-ray detection unit. In this case, the magnetic sensor is an example of the "area information acquisition unit" in the claims.

[0112] Furthermore, while the first to fourth embodiments described above show an example of detecting the relative arrangement (position and angle) of the X-ray detection unit 2 with respect to the X-ray irradiation unit 1 based on the position of the marker 22a in the optical image 60 captured by the optical camera 42, the present invention is not limited thereto. In the present invention, the relative angular relationship between the X-ray irradiation direction of the X-ray irradiation unit and the X-ray detection unit may be detected by detecting infrared rays, radio waves (electromagnetic waves), or ultrasonic waves. Alternatively, the relative angular relationship may be detected by arranging angle sensors in both the X-ray irradiation unit and the X-ray detection unit.

[0113] Furthermore, in the first to fourth embodiments described above, an example was shown in which the unit-side control unit 43 (guide light irradiation control unit) sets a region including an area overlapping with at least the eye 902 of the subject 900, based on the position of the shoulder 904 of the subject 900 detected from the optical image 60, as the guide light irradiation restriction region 80. However, the present invention is not limited thereto. In the present invention, the guide light irradiation control unit may detect the position of the subject's face or head from the optical image captured by the optical camera, and based on the detected position of the subject's face or head, set a region including an area overlapping with at least the eye position of the subject as the guide light irradiation restriction region.

[0114] Furthermore, in the first to fourth embodiments described above, the X-ray imaging apparatus 100 (X-ray imaging apparatus 400) is shown as a mobile X-ray imaging apparatus comprising a movable apparatus body 3, where the entire apparatus is movable. However, the present invention is not limited to this. For example, the present invention may also be applied to fixed X-ray imaging apparatuses, such as an X-ray imaging apparatus suspended from the ceiling of the imaging room, or an X-ray imaging apparatus fixed to the floor of the imaging room.

[0115] [Aspect] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0116] (Item 1) An X-ray irradiation unit that irradiates the subject with X-rays, An X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the subject, A guide light irradiation unit that emits guide light indicating the X-ray irradiation area to which X-rays are irradiated by the X-ray irradiation unit or the center position of the X-ray irradiation area, An optical camera that acquires an optical image for acquiring the guide light irradiation area to which the guide light is irradiated by the guide light irradiation unit, The system includes a guide light irradiation control unit that sets a guide light irradiation restriction region that includes at least an area overlapping with the eye position of the subject, and controls the irradiation of the guide light by the guide light irradiation unit based on the set guide light irradiation restriction region, The guide light irradiation control unit is ,before An X-ray imaging apparatus configured to obtain the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit based on the optical image acquired by the optical camera, geometrically calculate the guide light irradiation area based on the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit, and, when the guide light irradiation area overlaps with the guide light irradiation restriction area, to perform control to stop the irradiation of the guide light or to reduce the light intensity of the guide light irradiated from the guide light irradiation unit in at least the portion that overlaps with the guide light irradiation restriction area.

[0117] (Item 2) The X-ray imaging apparatus according to item 1, wherein the guide light irradiation control unit is configured to set a guide light irradiation restriction area that includes an area overlapping the position of the subject's face, and when the guide light irradiation area overlaps the set guide light irradiation restriction area that includes an area overlapping the position of the subject's face, it is configured to stop the irradiation of the guide light or to reduce the light intensity of the guide light irradiated from the guide light irradiation unit in at least the portion that overlaps the guide light irradiation restriction area.

[0118] (Item 3) beforeThe X-ray imaging apparatus according to item 1 or 2, wherein the guide light irradiation control unit is configured to acquire the guide light irradiation area based on the optical image captured by the optical camera.

[0119] (Item 4) The optical camera and the guide light irradiation unit are attached to the X-ray irradiation unit. The X-ray imaging apparatus according to item 3, wherein the guide light irradiation control unit is configured to acquire the relative positional relationship between the X-ray irradiation unit to which the guide light irradiation unit is attached and the X-ray detection unit based on the optical image captured by the optical camera, and to acquire the guide light irradiation area based on the acquired relative positional relationship between the X-ray irradiation unit and the X-ray detection unit.

[0120] (Item 5) The X-ray imaging apparatus according to item 3, wherein the guide light irradiation control unit is configured to set a guide light irradiation restriction area based on the optical image captured by the optical camera, and when the guide light irradiation area acquired based on the optical image overlaps with the set guide light irradiation restriction area, it is configured to stop the irradiation of the guide light or to reduce the light intensity of the guide light irradiated from the guide light irradiation unit in at least the portion that overlaps with the guide light irradiation restriction area.

[0121] (Item 6) The X-ray imaging apparatus according to item 5, wherein the guide light irradiation control unit is configured to detect the position of a specific part of the body located above the chest of the subject in the optical image captured by the optical camera, and to set a region including at least the area overlapping the position of the eyes of the subject as the guide light irradiation restriction region based on the detected position of the specific part.

[0122] (Item 7) The X-ray imaging apparatus according to item 6, wherein the guide light irradiation control unit is configured to detect the position of the subject's shoulder in the optical image captured by the optical camera, and to set a region including at least the area overlapping the position of the subject's eyes as the guide light irradiation restriction region based on the detected position of the subject's shoulder.

[0123] (Item 8) The X-ray imaging apparatus according to item 5, wherein the guide light irradiation control unit is configured to acquire the position of the X-ray detection unit based on the optical image captured by the optical camera, and to set a region including the area on the head side of the subject relative to the X-ray detection unit as the guide light irradiation restriction region based on the acquired position of the X-ray detection unit.

[0124] (Item 9) The guide light irradiation unit includes a first laser light irradiation unit that irradiates laser light in a line along a first direction, and a second laser light irradiation unit that irradiates laser light in a line along a second direction intersecting the first direction. The first laser beam irradiation unit and the second laser beam irradiation unit irradiate laser beams such that the laser beams emitted from each unit intersect at the center of the X-ray irradiation area. The X-ray imaging apparatus according to item 1 or 2, wherein the guide light irradiation control unit is configured to acquire the guide light irradiation area, which includes the irradiation area of ​​the laser light irradiated from each of the first laser light irradiation unit and the second laser light irradiation unit.

[0125] (Item 10) The guide light irradiation control unit is the first laser light irradiation unit If the irradiation area of ​​the laser light emitted from overlaps with the guide light irradiation limiting area, control is performed to stop the irradiation of laser light emitted from at least the first laser light irradiation unit. The second laser beam irradiation department The laser is irradiated from there. Light If the irradiation area overlaps with the guide light irradiation limiting area, , at least before Note: Second laser beam irradiation department The X-ray imaging apparatus described in item 9, which is configured to control the irradiation of the laser light being emitted.

[0126] (Item 11) The X-ray imaging apparatus according to item 1 or 2, further comprising a mobile type apparatus body that supports the aforementioned X-ray irradiation unit and is configured to be movable by having a plurality of wheels attached.

[0127] (Item 12) An X-ray imaging apparatus including an X-ray irradiation unit that irradiates a subject with X-rays, and an X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the subject, is attached to the X-ray irradiation unit and emits guide light that indicates the X-ray irradiation area to which X-rays are irradiated by the X-ray irradiation unit or the center position of the X-ray irradiation area, For acquiring the guide light irradiation area to which the guide light is irradiated by the guide light irradiation unit. Optical image Get Optical camera and, The system includes a guide light irradiation control unit that sets a guide light irradiation restriction region that includes at least an area overlapping with the eye position of the subject, and controls the irradiation of the guide light by the guide light irradiation unit based on the set guide light irradiation restriction region, The guide light irradiation control unit is the Optical camera The above obtained by Based on the optical image, the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit is obtained, and the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit is obtained. Based on this, the guide light irradiation area Geometrically calculated A positioning assist device for an X-ray imaging apparatus, configured to stop the irradiation of the guide light or reduce the light intensity of the guide light irradiated from the guide light irradiation unit when the guide light irradiation area overlaps with the guide light irradiation restriction area. [Explanation of Symbols]

[0128] 1 X-ray irradiation section 2 X-ray detection unit 3. Main body of the device 4. Positioning assist unit (positioning assist device for X-ray imaging equipment) 31 wheels 41, 441 Guide light irradiation section 41a Laser beam irradiation section (first laser beam irradiation section) 41b Laser beam irradiation section (first laser beam irradiation section) 42 Optical camera (region information acquisition unit) 43 Unit-side control unit (guide light irradiation control unit) 50, 450 guide light 51, 52 Laser light 60 Optical image (area acquisition information) 70, 70a, 70b, 470 Guide light illumination area 80, 280, 580, 680 Guide light irradiation limiting region 100, 400 X-ray imaging equipment 900 subjects 901 Face 902nd 903 Chest 904 Shoulder 905 Head

Claims

1. An X-ray irradiation unit that irradiates the subject with X-rays, An X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the subject, A guide light irradiation unit that emits guide light indicating the X-ray irradiation area to which X-rays are irradiated by the X-ray irradiation unit or the center position of the X-ray irradiation area, An optical camera that acquires an optical image for acquiring the guide light irradiation area to which the guide light is irradiated by the guide light irradiation unit, The system includes a guide light irradiation control unit that sets a guide light irradiation restriction region that includes at least an area overlapping with the eye position of the subject, and controls the irradiation of the guide light by the guide light irradiation unit based on the set guide light irradiation restriction region, The X-ray imaging apparatus is configured such that the guide light irradiation control unit acquires the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit based on the optical image acquired by the optical camera, geometrically calculates the guide light irradiation area based on the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit, and, when the guide light irradiation area overlaps with the guide light irradiation restriction area, controls to stop the irradiation of the guide light or to reduce the light intensity of the guide light irradiated from the guide light irradiation unit in at least the portion that overlaps with the guide light irradiation restriction area.

2. The X-ray imaging apparatus according to claim 1, wherein the guide light irradiation control unit is configured to set a guide light irradiation restriction area that includes an area overlapping with the position of the subject's face, and when the guide light irradiation area overlaps with the set guide light irradiation restriction area that includes an area overlapping with the position of the subject's face, it is configured to stop the irradiation of the guide light or to reduce the light intensity of the guide light irradiated from the guide light irradiation unit in at least the portion that overlaps with the guide light irradiation restriction area.

3. The X-ray imaging apparatus according to claim 1 or 2, wherein the guide light irradiation control unit is configured to acquire the guide light irradiation area based on the optical image captured by the optical camera.

4. The optical camera and the guide light irradiation unit are attached to the X-ray irradiation unit. The X-ray imaging apparatus according to claim 3, wherein the guide light irradiation control unit is configured to acquire the relative positional relationship between the X-ray irradiation unit to which the guide light irradiation unit is attached and the X-ray detection unit based on the optical image captured by the optical camera, and to acquire the guide light irradiation area based on the acquired relative positional relationship between the X-ray irradiation unit and the X-ray detection unit.

5. The X-ray imaging apparatus according to claim 3, wherein the guide light irradiation control unit is configured to set a guide light irradiation restriction area based on the optical image captured by the optical camera, and when the guide light irradiation area acquired based on the optical image overlaps with the set guide light irradiation restriction area, it is configured to stop the irradiation of the guide light or to reduce the light intensity of the guide light irradiated from the guide light irradiation unit in at least the portion that overlaps with the guide light irradiation restriction area.

6. The X-ray imaging apparatus according to claim 5, wherein the guide light irradiation control unit is configured to detect the position of a specific part of the body located above the chest of the subject in the optical image captured by the optical camera, and to set a region including at least a region overlapping the position of the eyes of the subject as the guide light irradiation restriction region based on the detected position of the specific part.

7. The X-ray imaging apparatus according to claim 6, wherein the guide light irradiation control unit is configured to detect the position of the subject's shoulder in the optical image captured by the optical camera, and to set a region including at least a region overlapping the position of the subject's eyes as the guide light irradiation restriction region based on the detected position of the subject's shoulder.

8. The X-ray imaging apparatus according to claim 5, wherein the guide light irradiation control unit is configured to acquire the position of the X-ray detection unit based on the optical image captured by the optical camera, and to set a region including the area on the head side of the subject relative to the X-ray detection unit as the guide light irradiation restriction region based on the acquired position of the X-ray detection unit.

9. The guide light irradiation unit includes a first laser light irradiation unit that irradiates laser light in a line along a first direction, and a second laser light irradiation unit that irradiates laser light in a line along a second direction intersecting the first direction. The first laser beam irradiation unit and the second laser beam irradiation unit irradiate laser beams such that the laser beams emitted from each unit intersect at the center of the X-ray irradiation area. The X-ray imaging apparatus according to claim 1 or 2, wherein the guide light irradiation control unit is configured to acquire the guide light irradiation area, which includes the irradiation area of ​​the laser light irradiated from each of the first laser light irradiation unit and the second laser light irradiation unit.

10. The X-ray imaging apparatus according to claim 9, wherein the guide light irradiation control unit is configured to stop the irradiation of laser light from at least the first laser light irradiation unit when the irradiation area of ​​the laser light irradiated from the first laser light irradiation unit overlaps with the guide light irradiation limiting area, and to stop the irradiation of laser light from at least the second laser light irradiation unit when the irradiation area of ​​the laser light irradiated from the second laser light irradiation unit overlaps with the guide light irradiation limiting area.

11. The X-ray imaging apparatus according to claim 1 or 2, further comprising a mobile type apparatus body that supports the X-ray irradiation unit and is equipped with a plurality of wheels to make it movable.

12. An X-ray imaging apparatus including an X-ray irradiation unit that irradiates a subject with X-rays, and an X-ray detection unit that detects X-rays irradiated from the X-ray irradiation unit and transmitted through the subject, is attached to the X-ray irradiation unit and emits guide light that indicates the X-ray irradiation area to which X-rays are irradiated by the X-ray irradiation unit or the center position of the X-ray irradiation area, An optical camera that acquires an optical image for acquiring the guide light irradiation area to which the guide light is irradiated by the guide light irradiation unit, The system includes a guide light irradiation control unit that sets a guide light irradiation restriction region that includes at least an area overlapping with the eye position of the subject, and controls the irradiation of the guide light by the guide light irradiation unit based on the set guide light irradiation restriction region, The positioning assist device for an X-ray imaging apparatus is configured such that the guide light irradiation control unit acquires the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit based on the optical image acquired by the optical camera, geometrically calculates the guide light irradiation area based on the relative positional relationship between the X-ray irradiation unit and the X-ray detection unit, and, when the guide light irradiation area overlaps with the guide light irradiation restriction area, controls to stop the irradiation of the guide light or to reduce the light intensity of the guide light irradiated from the guide light irradiation unit in at least the portion that overlaps with the guide light irradiation restriction area.

Images