X-ray diagnostic apparatus, x-ray diagnostic system, and image reconstruction method

Abstract

An X-ray diagnostic apparatus, an X-ray diagnostic system, and an image reconstruction method. The X-ray diagnostic apparatus includes an X-ray tube that irradiates an X-ray to an object, an X-ray detector that detects the X-ray transmitted through the object, a support portion that supports the X-ray tube and the X-ray detector, a moving mechanism that enables the X-ray tube and the X-ray detector to move, and a control portion that controls the X-ray tube and the X-ray detector to perform X-ray imaging, thereby collecting a plurality of X-ray image data. The X-ray diagnostic apparatus further includes sensors provided on the X-ray tube and the X-ray detector, respectively, to acquire vibration data of the X-ray tube and the X-ray detector. The control portion acquires, in advance, motion model information of the X-ray diagnostic apparatus based on structural analysis, i.e., a structural mathematical model. The control portion corrects the structural mathematical model of the X-ray diagnostic apparatus based on the vibration data acquired by the sensors, and generates a reconstructed image based on the corrected structural mathematical model and the plurality of X-ray image data.

Description

Technical Field

[0001] This application relates to X-ray diagnostic devices, X-ray diagnostic systems, and image reconstruction methods. Background Technology

[0002] Typically, X-ray image diagnostic device 1, such as Figure 11 As shown, the device includes an X-ray tube (or X-ray generating unit) 2, a platform 4 for placing the object to be examined 3, an X-ray detector (or simply detection unit) 5, a mechanism control unit 6, a C-arm 7 (or simply holding unit), a system control unit 8, an operation unit 9, an image processing and storage unit 10, and a display unit 11. The operation unit 9 includes a manual switch 12, a switch holding unit 13, and a user interface 14. In an X-ray image diagnostic device, the X-ray tube, detection unit, and their holding mechanism experience movement, deformation, and vibration due to gravity, driving force, and inertial force. The state of this deformation or vibration largely depends on the state of the holding mechanism. When reconstructing a three-dimensional X-ray image, the positional relationship between the three-dimensional position coordinates and the projected image is required. Therefore, the X-ray path needs to be calibrated.

[0003] However, the method disclosed in Patent Document 1 does not utilize the positional information of the X-ray path during three-dimensional scanning, but instead utilizes pre-made calibration data.

[0004] Figure 12 This is a schematic diagram of the calibration method for the X-ray path of the X-ray three-dimensional image diagnostic device used in Patent Document 1. The phantom is fixed to the top plate of a bed (not shown). The phantom used here is, for example, an acrylic material embedded with metal particles. The positions of these particles are defined in a three-dimensional position coordinate system as needed, either by design or by measurement. X-rays emitted from the X-ray focal point are projected onto the detector surface of the X-ray detector through the phantom. Accordingly, the positional correspondence between a specific point on the phantom and the projected detector surface is calculated. This correspondence is called the calibration data (Wobble table). The relationship between the three-dimensional position coordinates (x, y, z) and the coordinates (c, l) in the planar coordinate system on the two-dimensional projected image plane, i.e., the detector surface, is generally given by the following transformation (1).

[0005]

[0006] Here, matrix M is the calibration data. If the matrix is ​​expanded, it becomes the following form.

[0007]

[0008] For ease of calculation, m is defined. 34 =1.

[0009] Equations (1) and (2) provide the reconstruction space (x, y, z) corresponding to the pixels (c, l) of the projection plane image on the left. This allows a correlation to be established between the independent projection image data and the reconstruction space. The expanded form of the aforementioned matrix M is as follows.

[0010]

[0011] However, in the X-ray three-dimensional image diagnostic device of Patent Document 1, a calibration process using a special body membrane is required beforehand for each three-dimensional imaging device motion state. Therefore, there is a problem that three-dimensional imaging can only be performed in a state that has been calibrated beforehand.

[0012] Furthermore, in the method disclosed in Patent Document 2, an accelerometer installed on at least one of the X-ray tube, X-ray detector, and C-arm is used to collect acceleration data during rotational imaging, thereby generating calibration data that reflects the state of the device and reconstructing a three-dimensional image. The calibration data is then updated by comparing the acquired acceleration data with pre-collected acceleration data.

[0013] However, although Patent Document 2 can predict the X-ray path condition of the device under rigid motion by measuring the acceleration sensor, in reality, the X-ray tube and flat panel detector (FPD) positions obtained by extrapolating the rigid motion of the device based on the measurement point do not meet the rigid body condition. In particular, there is a problem that the elastic deformation (including vibration) of the holding structure of the X-ray tube and FPD cannot be ignored.

[0014] Patent Document 1: U.S. Patent No. 6,466,638 B1

[0015] Patent Document 2: Japanese Patent Application Publication No. 2019-180941 Summary of the Invention

[0016] The present invention was made in view of the above problems, and its purpose is to provide an X-ray diagnostic device, X-ray diagnostic system and image reconstruction method that can perform three-dimensional imaging without prior calibration using a special body membrane.

[0017] Technical solution 1 of the present invention is an X-ray diagnostic device, characterized in that,

[0018] It comprises: an X-ray tube that irradiates an object with X-rays, an X-ray detector that detects the X-rays transmitted through the object, a support portion that supports the X-ray tube and the X-ray detector, a moving mechanism that enables the X-ray tube and the X-ray detector to move, and a control portion that controls the X-ray tube and the X-ray detector to perform X-ray imaging, thereby collecting multiple X-ray image data.

[0019] The X-ray diagnostic device also includes sensors, which are respectively installed on the X-ray tube and the X-ray detector to acquire vibration data of the X-ray tube and the X-ray detector.

[0020] The control unit obtains in advance the motion model information of the X-ray diagnostic device based on structural analysis, i.e., the structural mathematical model.

[0021] The control unit corrects the structural mathematical model based on the vibration data obtained by the sensor, and generates a reconstructed image based on the corrected structural mathematical model and the multiple X-ray image data.

[0022] Alternatively, in technical solution 2, it could also be...

[0023] Based on the spatial position information of the detector surfaces of the X-ray tube and the X-ray detector, the control unit calculates the correspondence parameters between the detector surface (projection plane) of the X-ray detector and three-dimensional space, namely the calibration data M.

[0024] The control unit uses the obtained calibration data M to generate a reconstructed image.

[0025] Alternatively, in technical solution 3, the spatial location information can be obtained by prediction using the structural mathematical model.

[0026] Alternatively, in technical solution 4, the spatial position information can be obtained by actually measuring the X-ray diagnostic device through a displacement measurement system.

[0027] Alternatively, in technical solution 5, the control unit may revise the structural mathematical model based on a comparison between the vibration data of the pre-acquired structural mathematical model and the vibration data obtained through the sensor.

[0028] Alternatively, in technical solution 6, the structural mathematical model may be a motion model that reflects the spatial position information, vibration characteristics, and mechanical characteristics of the X-ray diagnostic device performing rotational imaging.

[0029] Alternatively, in technical solution 7, the moving mechanism may also include a walking mechanism that can move the X-ray diagnostic device automatically or manually.

[0030] Alternatively, in technical solution 8, the spatial position information may include: the focal vector X of the X-ray tube in a three-dimensional spatial coordinate system. s (x s ,y s ,z s The origin vector X0(x) of the X-ray detector f0 ,yf0 ,z f0 ); and the azimuth angle θ = θ(θ) of the detector plane, i.e., the projection plane, of the X-ray detector, expressed by the rotation angle relative to the three coordinate axes of the three-dimensional spatial coordinate system. x ,θ y ,θ z ),

[0031] The control unit calculates the coordinates (c,l) of the intersection point Pp of an X-ray path passing through any point P(x,y,z) in the three-dimensional spatial coordinate system and the detector surface in the planar coordinate system where the detector surface is located.

[0032] The relationship between point P and point Pp satisfies the following mathematical expression.

[0033]

[0034] The X-ray path has at least 6 channels, meaning there are at least 12 mathematical formulas. The control unit calculates the correspondence parameters between the projection plane and the three-dimensional reconstruction space, i.e., calibration data M, by solving the equations formed by these mathematical formulas. Using the obtained calibration data M, the X-ray three-dimensional image is reconstructed.

[0035] The calibration data M is the following matrix:

[0036]

[0037] Where, m 34 =1.

[0038] Alternatively, in technical solution 9, the X-ray diagnostic device may include a movable connecting element and structural units connected by the connecting element.

[0039] The connecting elements include rotary bearings, rollers, shafts, and slides.

[0040] The structural unit includes the X-ray tube, the X-ray detector, a detector chassis for mounting the X-ray detector, a C-arm, a support part for supporting the rotation and movement of the C-arm, a support column for supporting the support part, and a rotating arm for supporting the rotation of the support column.

[0041] The mathematical model is a digital twin.

[0042] The structural unit is represented by the mathematical model consisting of a mass element that includes mass and inertia, a spring element that represents the rigidity of the structural unit, and a damping element that represents vibration damping.

[0043] The connecting elements are represented by the structural mathematical model consisting of a mass element containing mass and inertia, a friction element resisting relative motion of movable degrees of freedom, a spring element representing rigidity, a damping element representing vibration attenuation, and a gap element between the connecting elements.

[0044] Alternatively, in technical solution 10, the friction element and the gap element may be parameters that represent the variable vibration characteristics of the X-ray diagnostic device during its use.

[0045] Alternatively, in technical solution 11, the control unit can quantitatively calculate the vibration characteristics in the digital twin using the vibration data.

[0046] Alternatively, in technical solution 12, the control unit may modify the structural mathematical model based on the calculated values ​​of the friction element and the clearance element.

[0047] Alternatively, in technical solution 13, the control unit may calculate the gap element based on the amplitude change of the vibration data obtained by the sensor.

[0048] Alternatively, in technical solution 14, the control unit can calculate the inherent vibration characteristics contained in the spectral data based on the vibration data obtained by the sensor, and calculate the friction element based on the inherent vibration characteristics.

[0049] Alternatively, in technical solution 15, the control unit may calculate the spatial position information of the X-ray tube and the detector surface of the X-ray detector based on the modified mathematical model.

[0050] Technical solution 16 of the present invention is an X-ray diagnostic system, characterized in that,

[0051] Including X-ray diagnostic equipment and remote servers,

[0052] The X-ray diagnostic device includes: an X-ray tube that irradiates X-rays onto a subject, an X-ray detector that detects the X-rays transmitted through the subject, a support unit that supports the X-ray tube and the X-ray detector, a moving mechanism that enables the X-ray tube and the X-ray detector to move, and a control unit that controls the X-ray tube and the X-ray detector to perform X-ray imaging, thereby collecting multiple X-ray image data.

[0053] The X-ray diagnostic device also includes:

[0054] The vibration data acquisition mechanism acquires vibration data of the X-ray tube and the X-ray detector by means of sensors respectively installed on the X-ray tube and the X-ray detector;

[0055] The vibration data transmitting mechanism transmits the vibration data to a remote server; and

[0056] Receiving agency

[0057] The remote server stores the motion model information of the X-ray diagnostic device based on structural analysis, i.e., the structural mathematical model. Based on the vibration data obtained from the sensors, the remote server corrects the structural mathematical model, predicts the spatial position information of the X-ray tube and the detector surface of the X-ray detector, and calculates the correspondence parameters between the detector surface (projection plane) of the X-ray detector and three-dimensional space, i.e., the calibration data M, based on the spatial position information.

[0058] The receiving unit receives the spatial location information and the calibration data M sent from the remote server.

[0059] The control unit uses the received calibration data M to generate a reconstructed image.

[0060] Alternatively, in technical solution 17, the spatial position information may include: the focal vector X of the X-ray tube in a three-dimensional spatial coordinate system. s (x s ,y s ,z s The origin vector X0(x) of the X-ray detector f0 ,y f0 ,z f0 ); and the azimuth angle θ = θ(θ) of the X-ray detector's detector surface, i.e., the projection plane, expressed by rotation angles relative to the three coordinate axes of the three-dimensional reconstructed spatial coordinate system. x ,θ y ,θ z ),

[0061] The remote server calculates the coordinates (c,l) of the intersection point Pp of an X-ray path passing through any point P(x,y,z) in the three-dimensional spatial coordinate system and the detector surface in the planar coordinate system where the detector surface is located.

[0062] The relationship between point P and point Pp satisfies the following mathematical expression.

[0063]

[0064] The X-ray pathways are at least 6, meaning there are at least 12 mathematical formulas. The remote server calculates the correspondence parameters between the projection plane and the three-dimensional reconstruction space, i.e., the calibration data M, by solving the equations formed by these mathematical formulas.

[0065] The calibration data M is the following matrix:

[0066]

[0067] Where, m 34 =1.

[0068] Technical solution 18 of the present invention is an image reconstruction method performed by an X-ray diagnostic device. The X-ray diagnostic device includes: an X-ray tube that irradiates X-rays onto a subject, an X-ray detector that detects the X-rays transmitted through the subject, a support portion that supports the X-ray tube and the X-ray detector, a moving mechanism that enables the X-ray tube and the X-ray detector to move, and a control portion that controls the X-ray tube and the X-ray detector to perform X-ray imaging, thereby collecting multiple X-ray image data.

[0069] The X-ray diagnostic device also includes sensors, which are respectively installed on the X-ray tube and the X-ray detector to acquire vibration data of the X-ray tube and the X-ray detector.

[0070] The image reconstruction method is characterized by the following:

[0071] The structural mathematical model information of the X-ray diagnostic device is obtained in advance based on structural analysis.

[0072] Based on the vibration data obtained by the sensor, the structural mathematical model of the X-ray diagnostic device is corrected, and a reconstructed image is generated based on the corrected structural mathematical model and the plurality of X-ray image data.

[0073] Alternatively, in technical solution 19, the calibration data M can be calculated based on the spatial position information of the detector surfaces of the X-ray tube and the X-ray detector, respectively, to determine the correspondence parameters between the detector surface (projection plane) and the three-dimensional reconstruction space.

[0074] The obtained calibration data M is used to reconstruct the image.

[0075] Alternatively, in technical solution 20, the spatial position information may include: the focal vector X of the X-ray tube in a three-dimensional spatial coordinate system. s (x s ,y s ,z s The origin vector X0(x) of the X-ray detector f0 ,y f0 ,z f0 ); and the azimuth angle θ = θ(θ) of the X-ray detector's detector surface, i.e., the projection plane, expressed by rotation angles relative to the three coordinate axes of the three-dimensional reconstructed spatial coordinate system. x ,θ y ,θz ),

[0076] Calculate the coordinates (c,l) of the intersection point Pp of an X-ray path passing through any point P(x,y,z) in the three-dimensional spatial coordinate system and the detector surface in the planar coordinate system where the detector surface is located.

[0077] The relationship between point P and point Pp satisfies the following mathematical expression.

[0078]

[0079] The X-ray pathways are at least 6, meaning there are at least 12 mathematical formulas. By solving the equations formed by these mathematical formulas, the correspondence parameters between the projection plane and the three-dimensional reconstruction space, i.e., the calibration data M, are calculated. Using the obtained calibration data M, image reconstruction is performed.

[0080] The calibration data M is the following matrix:

[0081]

[0082] Where, m 34 =1.

[0083] The effects of the invention

[0084] According to the X-ray diagnostic device, X-ray diagnostic system, and image reconstruction method of the present invention, since the correspondence parameter between the detector surface of the X-ray detector (i.e., the projection plane) and the three-dimensional reconstruction space (i.e., calibration data M) is calculated based on the spatial position information of the detector surface of the X-ray tube and the X-ray detector, and the X-ray diagnostic device is calibrated using the obtained calibration data M, it is not necessary to perform calibration work in advance using a special body membrane for the X-ray diagnostic device. Instead, the correspondence parameter calibration data M between the projection data and the three-dimensional reconstruction space can be obtained using the planar position information of the X-ray tube and the X-ray detector, and the X-ray diagnostic device can be calibrated using this calibration data M, thereby realizing the reconstruction of a three-dimensional image.

[0085] Furthermore, according to the X-ray diagnostic device, X-ray diagnostic system, and image reconstruction method of the present invention, since the correspondence parameters between the detector surface of the X-ray detector, i.e. the projection plane, and the three-dimensional reconstruction space, i.e. the calibration data M, are calculated based on the spatial position information of the detector surface of the X-ray tube and the X-ray detector, the calibration data of the C-arm of the X-ray diagnostic device in any state can be calculated.

[0086] Furthermore, according to the X-ray diagnostic device, X-ray diagnostic system, and image reconstruction method of the present invention, since the correspondence parameters between the X-ray detector surface (i.e., the projection plane) and the three-dimensional reconstruction space (i.e., the calibration data M) are calculated based on the spatial position information of the detector surface of the X-ray tube and the X-ray detector, not only fixed X-ray diagnostic devices, but also mobile X-ray diagnostic devices, can perform three-dimensional imaging without prior calibration using a special body membrane.

[0087] Furthermore, according to the X-ray diagnostic apparatus, X-ray diagnostic system, and image reconstruction method of the present invention, a structural mathematical model (Digital twin) reflecting the motion state of the apparatus (X-ray diagnostic apparatus) is created, including gap elements and friction elements of the connecting parts that can reflect the variable characteristics (i.e., vibration characteristics) of the apparatus. The vibration characteristics of the connecting parts are calculated based on vibration data, and the structural mathematical model (Digital twin) is corrected. Because the spatial position information of the X-ray tube and the detector surface of the X-ray detector is calculated based on the elastic deformation of each part of the entire apparatus, the calibration data M calculated based on the spatial position information of the X-ray tube and the detector surface of the X-ray detector has high accuracy. Attached Figure Description

[0088] Figure 1 This is a schematic diagram showing the overall X-ray diagnostic apparatus according to the first embodiment of the present invention.

[0089] Figure 2 This is a schematic diagram illustrating an X-ray diagnostic apparatus according to a first embodiment of the present invention.

[0090] Figure 3 It is a graph that shows the focal point of the X-ray tube and the spatial position information of the X-ray detector.

[0091] Figure 4 This is a schematic diagram showing the coordinate values ​​of six points in an arbitrarily selected reconstructed spatial coordinate system according to the first embodiment of the present invention.

[0092] Figure 5 It is a graph showing the calculated position information of the X-ray tube focal point and the X-ray detector according to the first embodiment of the present invention, as well as the coordinate values ​​of the intersection of the X-ray path and the detector surface of the point in the reconstructed spatial coordinate system in the planar coordinate system.

[0093] Figure 6 This is a chart showing calibration data for specific locations of the X-ray diagnostic apparatus according to the first embodiment of the present invention.

[0094] Figure 7 It is a diagram representing the structural mathematical model of the building blocks.

[0095] Figure 8It is a diagram representing a structural mathematical model of the connecting elements.

[0096] Figure 9 It is a graph representing representative time-domain vibration data under the condition of gaps.

[0097] Figure 10 It is a graph representing representative vibration data in the frequency domain.

[0098] Figure 11 This is a schematic diagram illustrating an existing X-ray three-dimensional image diagnostic device.

[0099] Figure 12 This is a schematic diagram illustrating the calibration method of the X-ray path in an X-ray three-dimensional imaging diagnostic device used in the prior art. Detailed Implementation

[0100] The X-ray diagnostic apparatus, X-ray diagnostic system, and image reconstruction method of the present invention will now be described with reference to the accompanying drawings.

[0101] [First Implementation Method]

[0102] The X-ray diagnostic apparatus 100 of the first embodiment of the present invention is described with reference to the accompanying drawings. Figure 1 This is a schematic diagram showing the overall structure of the X-ray diagnostic apparatus 100 according to the first embodiment of the present invention. Figure 1 As shown, the X-ray diagnostic apparatus 100 of the first embodiment of the present invention includes an X-ray tube (or X-ray generating unit) 102, a bed 104 for placing a subject 103, an X-ray detection unit (or simply detection unit) 105 capable of detecting X-rays emitted from the X-ray tube 102, a detector chassis (not shown) for mounting the X-ray detection unit, a mechanism control unit 106, a C-arm 107, a support unit 108 capable of supporting the rotation and sliding of the C-arm 107, a support column 109 supporting the support unit 108, a base 110 capable of supporting the rotation of the support column 109, a system control unit (not shown), an operation unit (not shown), an image processing and storage unit (not shown), and a display unit (not shown), etc.

[0103] The X-ray detection unit 105 in this invention uses a flat panel detector (FPD), but is not limited to this.

[0104] In addition, the operation unit includes various switches, switch holding parts, and user interface, etc. The operation unit, image processing and storage unit, and display unit can use known technologies.

[0105] In addition, the mechanism control unit 106, C-arm 107, support unit 108, support column 109, base 110 and the like constitute a moving mechanism that supports the X-ray tube and the X-ray detector and enables the X-ray tube and the X-ray detector to move.

[0106] In addition, the system control unit uses the projection data of X-rays emitted from the X-ray tube onto the detector surface of the X-ray detector to calculate a three-dimensional image of the reconstructed space. This system control unit corresponds to the "control unit" in the technical solution.

[0107] Furthermore, the base 110 can move the support column 109 automatically or manually, thereby enabling the X-ray diagnostic device to move. This base 110 corresponds to the "moving mechanism" in the technical solution.

[0108] In the X-ray diagnostic apparatus 100 of the first embodiment of the present invention, the X-ray tube 102, the X-ray detector 105, the detector chassis, the C-arm 107, the support 108, the support column 109, and the rotating arm are structural units of the X-ray diagnostic apparatus 100. Furthermore, the X-ray diagnostic apparatus 100 also includes movable connecting elements that connect each structural unit, such as rotary bearings, rollers, and slides. Thus, the X-ray diagnostic apparatus 100 includes movable connecting elements and structural units connected by these connecting elements.

[0109] Furthermore, as described above, the X-ray diagnostic apparatus 100 of the first embodiment of the present invention includes a base 110 capable of supporting the movement of the support column 109. However, it is not limited to the base 110, and may also include, for example... Figure 4 As shown, a rotating arm 111, capable of supporting the rotation of the support column 109, replaces the base 110. For convenience, in Figure 4 The diagram of the mechanism control unit is omitted.

[0110] Based on the spatial position information of the X-ray tube and the detector surface of the X-ray detector, the system control unit calculates the correspondence parameters between the detector surface (projection plane) of the X-ray detector and the three-dimensional reconstruction space, namely the calibration data M.

[0111] In the X-ray diagnostic apparatus 100 of the first embodiment of the present invention, the system control unit calculates the correspondence parameters between the detector surface (projection plane) of the X-ray detector 105 and the three-dimensional reconstruction space based on the spatial position information of the detector surfaces of the X-ray tube 102 and the X-ray detector 105. These correspondence parameters are the calibration data M used to calibrate the X-ray diagnostic apparatus. Furthermore, the system control unit reconstructs an X-ray image using the obtained calibration data M.

[0112] Specifically, the system control unit uses the structural mathematical model stored in the system control unit of the X-ray diagnostic device 100 to make predictions, or uses actual measurements (using a displacement measurement system composed of motion state capture and data analysis software) to obtain the spatial position information of the X-ray tube 102 and the X-ray detector 105, and calculates the calibration data M for generating the X-ray path based on this spatial position information. The aforementioned structural mathematical model can be a structural analysis model established using structural analysis software, but is not limited to this. The aforementioned structural mathematical model is a motion model that reflects the spatial position information, vibration characteristics, and mechanical characteristics of the X-ray diagnostic device 100 performing rotational imaging. Here, vibration characteristics include the frictional elements between the aforementioned connecting elements and the gap elements between the connecting elements that contribute to the vibration data during rotational imaging.

[0113] Figure 3 This is a graph representing the focal point of the X-ray tube 102 and the spatial position information of the X-ray detector 105, obtained by predicting using the structural mathematical model of the X-ray diagnostic device 100. Figure 3 (a) represents the focal vector X of the X-ray tube. s (x s ,y s ,z s ), Figure 3 (b) represents the origin vector X0(x) of the X-ray detector 105. f0 ,y f0 ,z f0 ), Figure 3 (c) represents the azimuth angle θ = θ(θ) of the detector plane, i.e., the projection plane, of the X-ray detector 105. x ,θ y ,θ z ).

[0114] Alternatively, the system control unit can obtain the spatial position information of the X-ray tube 102 and the X-ray detector 105 by performing actual measurements on the X-ray diagnostic device 100, and calculate the calibration data M for generating the X-ray path based on this spatial position information. The aforementioned actual measurements can be performed using a displacement measurement system composed of motion state capture and data analysis software, but are not limited to this.

[0115] In this embodiment, the system control unit generates a Wobble Table representing the correspondence between the projection data and the three-dimensional reconstruction space based on the known spatial position information of the X-ray tube 102 and the X-ray detector 105. That is, the following mathematical formula is obtained.

[0116]

[0117] In the observation coordinates, X sIt is the X-ray focus vector X of X-ray tube 102 in the three-dimensional reconstruction space coordinate system. s (x s ,y s ,z s X0 is the origin vector X0(x) of the X-ray detector 105. f0 ,y f0 ,z f0 ), θ(θ x ,θ y ,θ z ) is the orientation vector of the detector surface of the X-ray detector 105.

[0118] The following describes the method by which the system control unit of the X-ray diagnostic apparatus of the present invention calculates calibration data.

[0119] The spatial position information of the X-ray tube 102 and the X-ray detector 105 includes the X-ray focal vector X of the aforementioned X-ray tube 102. s (x s ,y s ,z s The origin vector X0(x) of the X-ray detector 105 f0 ,y f0 ,z f0 ), and the orientation vector θ(θ) of the detector surface. x ,θ y ,θ z ).

[0120] The azimuth vector θ of the detector plane is represented by the rotation angle relative to the three coordinate axes of the three-dimensional reconstruction space coordinate system (reference coordinate system). The azimuth angle θ of the detector plane, i.e., the projection plane, of the X-ray detector 105 is θ = θ(θ x ,θ y ,θ z Following the order of rotation along the z-axis → y-axis → x-axis, as follows: Figure 1 As shown, the origin of the X-ray detector 105 is taken as the origin of the coordinate system, and the axes corresponding to the pixels of the detector surface of the X-ray detector 105 are defined as the C-axis and L-axis, respectively. The normal vector of the plane of the detector surface of the X-ray detector 105 is defined as the V-axis. At this time, the transformation matrix from the three-dimensional reconstruction space coordinate system to the X-ray detector coordinate system is as follows (4).

[0121]

[0122] The rotation coordinate transformation matrix R in equation (4) is represented by the following equation (5).

[0123]

[0124] Here, C x =cosθx S x =sinθ x .

[0125] t4 (t 14 ,t 24 ,t 34 ) can be represented in the following form.

[0126]

[0127] The detector plane equation of the X-ray detector 105 can be expressed by the following equation (6).

[0128]

[0129] Any point P in the reconstructed three-dimensional coordinate system i (x pi ,y pi ,z pi The linear equation of the X-ray path can be expressed by the following equation (7).

[0130]

[0131] The intersection point P of the aforementioned X-ray path and detector surface pi (x ppi ,y ppi ,z ppi The result can be obtained by combining equations (6) and (7), and is defined as {P} in the plane coordinate system where the detector surface is located. pi} f (c i ,l i ,v i =0).

[0132] On the other hand, equation (2) can be used to obtain equation (8).

[0133]

[0134] P i (x pi ,y pi ,z pi ) and {P pi} f (c i ,l i ,v i =0) satisfies equation (8), therefore, using any 6 or more points P iThe solution to equation (8), i.e., the calibration data M (Wobble table), can be obtained. In other words, there are at least 6 X-ray paths, i.e., at least 12 mathematical expressions as shown in equation (8). The system control unit calculates the correspondence parameters between the detector surface, i.e., the projection plane, and the three-dimensional reconstruction space, i.e., the calibration data M, by solving the equation composed of at least 12 mathematical expressions, and reconstructs the three-dimensional X-ray image using the obtained calibration data M.

[0135] The calibration data M is the following matrix:

[0136]

[0137] Where, m 34 =1.

[0138] Figure 4 It represents 6 points P in an arbitrarily selected reconstructed image coordinate system. i A schematic diagram. Figure 5 This represents the focal point of the X-ray tube 102 and the position information of the X-ray detector, as well as the calculated intersection point P of the X-ray path and the detector surface. pi (x ppi ,y ppi ,z ppi The coordinates of {P} in the plane coordinate system where the detector surface is located pi} f The chart. Figure 6 This is a chart representing the calibration data M obtained by the above method.

[0139] exist Figure 5 and Figure 6 The data above are shown in the figure, respectively, when the C-shaped arm 107 rotates around the axis of the support part 108 at different angles.

[0140] LAO (Left Anterior Oblique): Left anterior oblique refers to rotation in one direction about the axis of the support 108.

[0141] RAO (Right Anterior Oblique): Right anterior oblique refers to rotation in the opposite direction about the axis of the support 108.

[0142] Home: Initial State

[0143] RAO90: Lean forward 90° to the right

[0144] RAO60: Right forward tilt 60°

[0145] RAO30: Right forward tilt 30°

[0146] Home0: Initial 0°

[0147] LAO30: Left forward tilt 30°

[0148] LAO60: Left forward tilt 60°

[0149] LAO90: Lean forward 90° to the left

[0150] In order to predict the positional information of the X-ray tube 102 and the X-ray detector 105 using the structural mathematical model of the X-ray diagnostic device, the structural mathematical model must be able to reflect the actual state of the X-ray diagnostic device. Here, the structural mathematical model is a digital twin.

[0151] First, the X-ray diagnostic apparatus 100 is capable of supporting the X-ray tube 102 and the X-ray detector 105, and is capable of enabling the X-ray tube 102 and the X-ray detector 105 to function properly. To this end, the X-ray diagnostic apparatus 100, as described above, includes connecting elements and structural units connected by these connecting elements.

[0152] Figure 7 It is a diagram representing the structural mathematical model of the building blocks. In Figure 7 In this context, k represents the spring, m represents the mass, and C represents the damping.

[0153] The structural units of the X-ray diagnostic device 100, such as the X-ray tube 102, X-ray detector 105, detector chassis, C-arm 107, support 108, support column 109, and rotating arm, are as follows: Figure 7 The structure is represented by a mathematical model consisting of a mass element that includes mass and inertia, a spring element that represents the rigidity of the building unit, and a damping element that represents vibration attenuation.

[0154] Figure 8 It is a diagram representing the structural mathematical model of the connecting elements. Figure 8 In this context, k represents the spring, m represents the mass, C represents the damping, δ represents the clearance, and f represents the friction.

[0155] The connecting elements such as rotating bearings, rollers, shafts, and slides are represented by a structural mathematical model consisting of a mass element containing mass and inertia, a friction element resisting relative motion, a spring element representing rigidity, a damping element representing vibration attenuation, and a gap element between the connecting elements. Furthermore, the friction of the aforementioned connecting elements is represented by a structural mathematical model in the form of external forces.

[0156] Since the mechanical properties of the materials used in the structural units, such as mass, elasticity, and viscosity, remain unchanged during the warranty period of the X-ray diagnostic device 100, the characteristic parameters of its structural mathematical model do not change after the X-ray diagnostic device 100 leaves the factory or is maintained. However, the connecting elements experience wear and loosening with the use of the X-ray diagnostic device 100, and the characteristic parameters of their structural mathematical model change over time. Generally, structural systems have multiple natural vibration modes. Each natural vibration mode depends on the low-rigidity structural element that governs it. In the X-ray diagnostic device 100, the low-rigidity structural element is the connecting element. From the low-order natural vibration state, the connecting elements that affect the vibration can be identified. These connecting elements affect the state of the X-ray path. In experimental measurements, the bearings and rollers that change over time have the greatest impact on the changes in the state of the X-ray path. For example, the connecting elements of the support retaining bearing, the support retaining bearing, the C-arm retaining roller, and the X-ray detector retaining bearing have a significant impact on the X-ray path.

[0157] Next, the method for updating the structural mathematical model of the X-ray diagnostic device in real time on the actual X-ray diagnostic device will be explained.

[0158] While specialized equipment can be used to measure these variable characteristic parameters (friction elements, backlash elements), it is difficult to perform these measurements at the site of X-ray diagnostic equipment use. In this invention, instead of directly measuring the vibration characteristics of the connection elements, identification is performed based on vibration data (ODS: Operating Deflection Shapes) measured under specified operations during the actual operating conditions of the X-ray diagnostic equipment 100. The parameters representing the characteristics of the friction element and backlash element in the aforementioned connection elements change with the use of the X-ray diagnostic equipment 100. Vibration data is acquired each time the X-ray diagnostic equipment 100 operates using sensors (e.g., accelerometers, not shown) mounted on the X-ray diagnostic equipment 100. The vibration data is measured using strain gauges and / or accelerometers, but is not limited to these methods. Furthermore, the relationship between the vibration data and the aforementioned friction and backlash elements has been calibrated in a laboratory setting.

[0159] In a first embodiment of the invention, an accelerometer is mounted on the X-ray tube 102 and the X-ray detector 105. These mounting locations are most sensitive to vibrations of the X-ray diagnostic device 100 and are directly related to the motion characteristics of the X-ray path. Acceleration (vibration) values ​​at test points are obtained in a specified three-dimensional scan sequence. By comparing this time-domain vibration data and the frequency-domain data obtained by performing a Fourier transform on this vibration data with measurement data from the same scan sequence performed in the laboratory, the state changes of the X-ray diagnostic device 100 can be determined. Through calibration, the variable characteristic parameters in the structural mathematical model can be quantitatively calculated.

[0160] The characteristic parameter of the aforementioned gap element is the gap amount δ. If there is a backlash, the X-ray diagnostic device 100 will experience significant backlash during three-dimensional scanning. This backlash causes a significant change in the amplitude of the aforementioned time-domain vibration data. The gap amount can be calculated by calculating the change in amplitude. The gap amount δ is a function of the steep change in the amplitude of the vibration data in the time domain. Figure 9 This is a graph representing representative time-domain amplitude data with the presence of a gap. The vertical axis represents the amplitude of the vibration, and the horizontal axis represents time. The amplitude without a gap is d, while with a gap, the amplitude increases to D under specific motion conditions. The gap amount δ can be represented as a function of the amplitude change (Dd).

[0161] The aforementioned frictional elements can be represented by a structural mathematical model of frictional force, which changes with wear and loosening of the connecting parts. Low-rigidity components such as bearings and rollers in the X-ray diagnostic device 100 will loosen and wear with use, causing changes in frictional force, while the structural rigidity of the X-ray diagnostic device 100 remains relatively stable. Friction consumes kinetic energy, thus attenuating vibration. The vibration of the X-ray diagnostic device 100 is random vibration, and the current vibration state is influenced by the attenuation of excitations generated at each moment in the past. Such vibrational characteristics can be represented by the half-amplitude of the natural vibration appearing in the frequency domain vibration data. According to vibration theory, frictional force, like viscous properties, is related to the frequency response characteristics of vibration. Viscous properties are related to the half-amplitude of the vibration response at the resonant frequency. Figure 10 This is a graph representing representative vibration data in the frequency domain (usually an FFT of time-domain vibration data), with the vertical axis representing amplitude and the horizontal axis representing frequency. In multi-degree-of-freedom structural systems, there are multiple natural vibrations, and each friction element is most relevant to a specific natural vibration. The frictional force f can be identified as a function of the relative amount of half-amplitude (ω2-ω1) / ω0.

[0162] Next, the method of using digital twins to predict X-ray pathways in the system control unit will be explained.

[0163] The digital twin of the X-ray diagnostic device 100, constructed from a structural mathematical model, is defined by a prescribed coordinate system. When defining the state of the X-ray diagnostic device 100, the coordinate system of the digital twin is also associated with the global coordinate system to represent the gravitational field associated with it. This global coordinate system is directly used to define the three-dimensional reconstruction space. The direction of the gravitational field is known in this global coordinate system. The orientation of the X-ray diagnostic device 100 refers to the state in which the encoder (or other sensor) mounted on the X-ray diagnostic device 100 displays no deformation in the global coordinate system. The initial state (static state) of the X-ray diagnostic device 100 refers to the state resulting from the sum of the aforementioned no-deformation state and the elastic deformation and gap changes caused by the gravitational field. The digital twin of the X-ray diagnostic device 100 is calculated from its initial state through dynamic analysis under the gravitational field and predetermined driving conditions (driving force or driving velocity / displacement). That is, the system control unit defines the initial state of the X-ray diagnostic device 100 in the three-dimensional reconstruction space through a digital twin, and further applies the gravitational field and predetermined driving conditions as external forces to the digital twin, calculating the actual state of the X-ray diagnostic device 100 through dynamic analysis. The state at every moment includes the X-ray focal vector X of the aforementioned X-ray tube 102. s (x s ,y s ,z s The origin vector X0(x) of the X-ray detector 105 f0 ,y f0 ,z f0 The azimuth angle θ = θ(θ) of the detector plane, i.e., the projection plane, of the X-ray detector 105 is expressed by the rotation angle relative to the three coordinate axes of the three-dimensional reconstruction space coordinate system. x ,θ y ,θ z Spatial location information such as )

[0164] Using the above method, the system control unit can generate X-ray calibration data M by utilizing the spatial position information of the X-ray tube 102 and the X-ray detector 105 obtained from digital twin prediction. Furthermore, the system control unit uses the obtained calibration data M to calibrate the X-ray diagnostic device 100.

[0165] [Second Implementation]

[0166] The X-ray diagnostic device 100 of the second embodiment is based on the first embodiment. After establishing a structural mathematical model in the laboratory, the structural mathematical model is modified during the actual use of the X-ray diagnostic device 100.

[0167] Specifically, similar to the first embodiment, sensors are installed at vibration-sensitive locations, such as the X-ray tube 102 and the X-ray detector 105, and the structural mathematical model is calculated and analyzed under the same scanning sequence. The system control unit obtains the motion information of the X-ray diagnostic device 100 based on structural analysis, i.e., the aforementioned structural mathematical model, in advance, and corrects the structural mathematical model of the X-ray diagnostic device 100 based on the vibration data obtained by the sensors, and calculates a three-dimensional image of the reconstructed space based on the corrected structural mathematical model.

[0168] Unlike the first embodiment, where the system control unit corrects the structural mathematical model based on a comparison between vibration data from a pre-obtained structural mathematical model of the X-ray diagnostic device 100 and vibration data obtained from sensors, in the second embodiment, the system control unit can predict the vibration state at the actual sensor installation location based on the pre-obtained structural mathematical model. The system control unit compares the actually measured vibration data with the vibration data calculated by the structural mathematical model. When the actually measured vibration data differs from the vibration data calculated by the structural mathematical model, the structural mathematical model is corrected based on the actually measured vibration data. Here, the method for measuring vibration (sensor selection, use, and installation), vibration data acquisition, and processing are the same as in the first embodiment, so descriptions are omitted.

[0169] In addition, the system control unit calculates the gap element based on the amplitude change of the vibration data obtained by the sensor.

[0170] In addition, the system control unit can calculate the inherent vibration characteristics contained in the spectral data based on the vibration data obtained by the sensor, and calculate the friction element based on the inherent vibration characteristics.

[0171] Furthermore, the system control unit corrects the structural mathematical model based on the calculated values ​​of friction and gap elements. Based on the corrected structural mathematical model, the system control unit calculates the spatial position information of the detector surfaces of the X-ray tube 102 and the X-ray detector 105.

[0172] [Third Implementation Method]

[0173] In the first embodiment of the present invention, the structural mathematical model is stored in the system control unit of the X-ray diagnostic device 100. However, it is not limited to this; the structural mathematical model can also be stored on a remote server using current Internet of Things (IoT) technology. The X-ray diagnostic system 200 of the third embodiment of the present invention includes an X-ray diagnostic device 100 and a remote server (not shown). The structural mathematical model (digital twin) of the X-ray diagnostic device 100 is stored on the remote server. Whenever the imaging parameters of the X-ray diagnostic device 100 are sent to the remote server, the remote server sends to the X-ray diagnostic device 100 the spatial position information of the X-ray tube 102 and the X-ray detector 105 corresponding to the imaging state, as well as calibration data representing the correspondence between the projection data and the three-dimensional reconstruction space.

[0174] Specifically, the X-ray diagnostic device 100 in the X-ray diagnostic system 200 of the third embodiment of the present invention further includes, based on the X-ray diagnostic device 100 of the first embodiment: a vibration data acquisition mechanism (not shown), which acquires vibration data of the X-ray tube 102 and the X-ray detector 105 by means of sensors respectively installed on the X-ray tube 102 and the X-ray detector 105; a vibration data transmission mechanism (not shown), which transmits the vibration data to a remote server; and a receiving mechanism (not shown).

[0175] In addition, the remote server in the X-ray diagnostic system 200 stores the motion model information of the X-ray diagnostic device 100 based on structural analysis, namely the structural mathematical model. Based on the vibration data obtained by the sensor, the remote server corrects the structural mathematical model, predicts the spatial position information of the detector surface of the X-ray tube 102 and the X-ray detector 105, and calculates the correspondence parameters between the detector surface of the X-ray detector 105, i.e. the projection plane, and the three-dimensional space, i.e., the calibration data M, based on the spatial position information.

[0176] The receiving unit receives spatial location information and calibration data M sent from a remote server. Then, the system control unit uses the received calibration data M to reconstruct a three-dimensional X-ray image.

[0177] Here, the method by which the remote server calculates the calibration data M is the same as the method by which the system control unit calculates the calibration data M in the first embodiment. That is, any point P in the three-dimensional reconstructed spatial coordinate system... i (x pi ,y pi ,z pi The X-ray path has at least 6 X-ray paths and at least 12 mathematical expressions as shown in equation (8). The remote server calculates the correspondence parameters between the detector surface, i.e. the projection plane, and the three-dimensional reconstruction space, i.e. the calibration data M, by solving the equation composed of at least 12 mathematical expressions, and sends the calibration data M to the receiving mechanism of the X-ray diagnostic device 100.

[0178] Next, the system control unit of the X-ray diagnostic device 100 reconstructs a three-dimensional X-ray image using the calibration data M received by the receiving mechanism.

[0179] [Effects]

[0180] According to the X-ray diagnostic device, X-ray diagnostic system, and image reconstruction method of the present invention, since the correspondence parameter between the detector surface of the X-ray detector (i.e., the projection plane) and the three-dimensional reconstruction space (i.e., calibration data M) is calculated based on the spatial position information of the detector surface of the X-ray tube and the X-ray detector, and the X-ray diagnostic device is calibrated using the obtained calibration data M, it is not necessary to perform calibration work in advance using a special body membrane for the X-ray diagnostic device. Instead, the correspondence parameter calibration data M between the projection data and the three-dimensional reconstruction space can be obtained using the planar position information of the X-ray tube and the X-ray detector, and the X-ray diagnostic device can be calibrated using this calibration data M, thereby realizing the reconstruction of a three-dimensional image.

[0181] Furthermore, according to the X-ray diagnostic device, X-ray diagnostic system, and image reconstruction method of the present invention, since the correspondence parameters between the detector surface of the X-ray detector, i.e. the projection plane, and the three-dimensional reconstruction space, i.e. the calibration data M, are calculated based on the spatial position information of the detector surface of the X-ray tube and the X-ray detector, the calibration data of the C-arm of the X-ray diagnostic device in any state can be calculated.

[0182] Furthermore, according to the X-ray diagnostic device, X-ray diagnostic system, and image reconstruction method of the present invention, since the correspondence parameters between the X-ray detector surface (i.e., the projection plane) and the three-dimensional reconstruction space (i.e., the calibration data M) are calculated based on the spatial position information of the detector surface of the X-ray tube and the X-ray detector, not only fixed X-ray diagnostic devices, but also mobile X-ray diagnostic devices, can perform three-dimensional imaging without prior calibration using a special body membrane.

[0183] Furthermore, according to the X-ray diagnostic apparatus, X-ray diagnostic system, and image reconstruction method of the present invention, a structural mathematical model (Digital twin) reflecting the motion state of the apparatus (X-ray diagnostic apparatus) is created, including gap elements and friction elements of the connecting parts that can reflect the variable characteristics (i.e., vibration characteristics) of the apparatus. The vibration characteristics of the connecting parts are calculated based on vibration data, and the structural mathematical model (Digital twin) is corrected. Because the spatial position information of the X-ray tube and the detector surface of the X-ray detector is calculated based on the elastic deformation of each part of the entire apparatus, the calibration data M calculated based on the spatial position information of the X-ray tube and the detector surface of the X-ray detector has high accuracy.

[0184] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the above description is merely a specific example of the present invention, used to understand the present invention, and is not intended to limit the scope of the present invention. Those skilled in the art can make various modifications and combinations to the embodiments based on the technical concept of the present invention, and the resulting methods are also included within the scope of the present invention.

Claims

1. An X-ray diagnostic device, characterized in that, It comprises: an X-ray tube that irradiates an object with X-rays, an X-ray detector that detects the X-rays transmitted through the object, a support portion that supports the X-ray tube and the X-ray detector, a moving mechanism that enables the X-ray tube and the X-ray detector to move, and a control portion that controls the X-ray tube and the X-ray detector to perform X-ray imaging, thereby collecting multiple X-ray image data. The X-ray diagnostic device also includes sensors, which are respectively installed on the X-ray tube and the X-ray detector to acquire vibration data of the X-ray tube and the X-ray detector. The control unit obtains in advance the motion model information of the X-ray diagnostic device based on structural analysis, i.e., the structural mathematical model. The control unit corrects the structural mathematical model based on the vibration data obtained by the sensor, and generates a reconstructed image based on the corrected structural mathematical model and the multiple X-ray image data. The control unit corrects the structural mathematical model based on a comparison between the vibration data from the pre-acquired structural mathematical model and the vibration data obtained through the sensors. The structural mathematical model is a motion model that reflects the spatial position information, vibration characteristics, and mechanical characteristics of the X-ray diagnostic device during rotational imaging. The X-ray diagnostic device includes a movable connecting element and structural units connected by the connecting element. The connecting elements include rotary bearings, rollers, shafts, and slides. The structural unit includes the X-ray tube, the X-ray detector, a detector chassis for mounting the X-ray detector, a C-arm, a support part for supporting the rotation and movement of the C-arm, a support column for supporting the support part, and a rotating arm for supporting the rotation of the support column. The mathematical model is a digital twin. The structural unit is represented by the mathematical model consisting of a mass element that includes mass and inertia, a spring element that represents the rigidity of the structural unit, and a damping element that represents vibration damping. The connecting elements are represented by the structural mathematical model consisting of a mass element containing mass and inertia, a friction element resisting relative motion of movable degrees of freedom, a spring element representing rigidity, a damping element representing vibration attenuation, and a gap element between the connecting elements.

2. The X-ray diagnostic device as described in claim 1, characterized in that, Based on the spatial position information of the detector surfaces of the X-ray tube and the X-ray detector, the control unit calculates the correspondence parameters between the detector surface (projection plane) of the X-ray detector and three-dimensional space, namely the calibration data M. The control unit uses the obtained calibration data M to generate a reconstructed image.

3. The X-ray diagnostic device as described in claim 2, characterized in that, The spatial location information is obtained by prediction through the structural mathematical model.

4. The X-ray diagnostic device as described in claim 2, characterized in that, The spatial location information is obtained by actually measuring the X-ray diagnostic device using a displacement measurement system.

5. The X-ray diagnostic device as described in claim 1, characterized in that, The moving mechanism also includes a walking mechanism that enables the X-ray diagnostic device to move automatically or manually.

6. The X-ray diagnostic device as described in claim 1, characterized in that, The friction element and the gap element are parameters that represent the variable vibration characteristics of the X-ray diagnostic device during its use.

7. The X-ray diagnostic device as described in claim 6, characterized in that, The control unit uses the vibration data to quantitatively calculate the vibration characteristics in the digital twin.

8. The X-ray diagnostic apparatus as described in claim 7, characterized in that, The control unit modifies the structural mathematical model based on the calculated values ​​of the friction element and the clearance element.

9. The X-ray diagnostic apparatus as described in claim 7, characterized in that, The control unit calculates the gap element based on the amplitude change of the vibration data obtained by the sensor.

10. The X-ray diagnostic apparatus as described in claim 7, characterized in that, The control unit calculates the inherent vibration characteristics contained in the spectral data based on the vibration data obtained by the sensor, and calculates the friction element based on the inherent vibration characteristics.

11. The X-ray diagnostic apparatus as described in claim 8, characterized in that, The control unit calculates the spatial position information of the X-ray tube and the detector surface of the X-ray detector based on the modified mathematical model.

12. An X-ray diagnostic system, characterized in that, Including X-ray diagnostic equipment and remote servers, The X-ray diagnostic device includes: an X-ray tube that irradiates X-rays onto a subject, an X-ray detector that detects the X-rays transmitted through the subject, a support unit that supports the X-ray tube and the X-ray detector, a moving mechanism that enables the X-ray tube and the X-ray detector to move, and a control unit that controls the X-ray tube and the X-ray detector to perform X-ray imaging, thereby collecting multiple X-ray image data. The X-ray diagnostic device also includes: The vibration data acquisition mechanism acquires vibration data of the X-ray tube and the X-ray detector by means of sensors respectively installed on the X-ray tube and the X-ray detector; The vibration data transmitting mechanism sends the vibration data to a remote server; as well as Receiving agency The remote server stores the motion model information of the X-ray diagnostic device based on structural analysis, i.e., the structural mathematical model. Based on the vibration data obtained from the sensors, the remote server corrects the structural mathematical model, predicts the spatial position information of the X-ray tube and the detector surface of the X-ray detector, and calculates the correspondence parameters between the detector surface (projection plane) of the X-ray detector and three-dimensional space, i.e., the calibration data M, based on the spatial position information. The receiving unit receives the spatial location information and the calibration data M sent from the remote server. The control unit uses the received calibration data M to generate a reconstructed image. The control unit corrects the structural mathematical model based on a comparison between the vibration data from the pre-acquired structural mathematical model and the vibration data obtained through the sensors. The structural mathematical model is a motion model that reflects the spatial position information, vibration characteristics, and mechanical characteristics of the X-ray diagnostic device during rotational imaging. The X-ray diagnostic device includes a movable connecting element and structural units connected by the connecting element. The connecting elements include rotary bearings, rollers, shafts, and slides. The structural unit includes the X-ray tube, the X-ray detector, a detector chassis for mounting the X-ray detector, a C-arm, a support part for supporting the rotation and movement of the C-arm, a support column for supporting the support part, and a rotating arm for supporting the rotation of the support column. The mathematical model is a digital twin. The structural unit is represented by the mathematical model consisting of a mass element that includes mass and inertia, a spring element that represents the rigidity of the structural unit, and a damping element that represents vibration damping. The connecting elements are represented by the structural mathematical model consisting of a mass element containing mass and inertia, a friction element resisting relative motion of movable degrees of freedom, a spring element representing rigidity, a damping element representing vibration attenuation, and a gap element between the connecting elements.

13. An image reconstruction method, performed by an X-ray diagnostic device, the X-ray diagnostic device comprising: an X-ray tube irradiating an object to be examined with X-rays, an X-ray detector detecting X-rays transmitted through the object to be examined, a support portion supporting the X-ray tube and the X-ray detector, a moving mechanism capable of moving the X-ray tube and the X-ray detector, and a control portion controlling the X-ray tube and the X-ray detector to perform X-ray imaging, thereby collecting multiple X-ray image data. The X-ray diagnostic device also includes sensors, which are respectively installed on the X-ray tube and the X-ray detector to acquire vibration data of the X-ray tube and the X-ray detector. The image reconstruction method is characterized by the following: The structural mathematical model information of the X-ray diagnostic device is obtained in advance based on structural analysis. Based on the vibration data obtained by the sensor, the structural mathematical model of the X-ray diagnostic device is corrected, and a reconstructed image is generated based on the corrected structural mathematical model and the multiple X-ray image data. The control unit corrects the structural mathematical model based on a comparison between the vibration data from the pre-acquired structural mathematical model and the vibration data obtained through the sensors. The structural mathematical model is a motion model that reflects the spatial position information, vibration characteristics, and mechanical characteristics of the X-ray diagnostic device during rotational imaging. The X-ray diagnostic device includes a movable connecting element and structural units connected by the connecting element. The connecting elements include rotary bearings, rollers, shafts, and slides. The structural unit includes the X-ray tube, the X-ray detector, a detector chassis for mounting the X-ray detector, a C-arm, a support part for supporting the rotation and movement of the C-arm, a support column for supporting the support part, and a rotating arm for supporting the rotation of the support column. The mathematical model is a digital twin. The structural unit is represented by the mathematical model consisting of a mass element that includes mass and inertia, a spring element that represents the rigidity of the structural unit, and a damping element that represents vibration damping. The connecting elements are represented by the structural mathematical model consisting of a mass element containing mass and inertia, a friction element resisting relative motion of movable degrees of freedom, a spring element representing rigidity, a damping element representing vibration attenuation, and a gap element between the connecting elements.

14. The image reconstruction method as described in claim 13, characterized in that, Based on the spatial position information of the detector surfaces of the X-ray tube and the X-ray detector, the correspondence parameters between the detector surface (projection plane) and the three-dimensional reconstruction space of the X-ray detector, i.e., the calibration data M, are calculated. The obtained calibration data M is used to reconstruct the image.

Images