Chest-imitating rib forming device and method

Abstract

The invention discloses a chest-imitating rib forming device which comprises a heating box body, an embracing device is arranged in the heating box body, a rib connecting plate is connected to the embracing device and made of memory alloy, electric telescopic rods are distributed on the top in the heating box body, and the lower ends of the electric telescopic rods are connected with a shaping rod assembly; the shaping rod assembly is located over the rib connecting plate. The heating box body is provided with a controller, the controller comprises a CT image two-dimensional processing module, a three-dimensional reconstruction module, a point cloud matching and path planning module and a driving signal generation module, and the driving signal generation module is electrically connected with the electric telescopic rod and the shaping rod assembly. The invention further discloses a breast-imitating rib forming method. The chest-imitating rib piece manufactured through the manufacturing method can replace an unfinished 3D printing rib piece so as to maintain the respiratory function of a patient, and the situation that the treatment opportunity is delayed due to waiting is avoided.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a device and method for forming a simulated rib cage. Background Technology

[0002] The sternum is a flat bone located in the center of the anterior chest wall, shaped like a short sword. It consists of three parts: the manubrium, the body, and the xiphoid process. The sternum connects to the ribs on both sides, and the posterior ends of the ribs connect to the thoracic vertebrae, forming the thoracic cage. It plays an important role in protecting the mediastinum and the internal organs of the thoracic cavity. Due to common diseases of the sternum or ribs, such as tumors, infections, radiation ulcers, trauma, and congenital malformations, sternal and rib resection surgery is often required, resulting in defects in the sternum or ribs, which undoubtedly necessitate thoracic cage reconstruction.

[0003] Currently, 3D printing and other methods are often used in clinical practice to reconstruct the thoracic cavity. However, this method has a significant time lag, which greatly delays the patient's surgery time, delays treatment, and reduces the patient turnover rate. Summary of the Invention

[0004] In view of the existing technical problems, the present invention provides a device and method for forming a simulated rib cage to solve the problems in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A rib-shaped device includes a heating chamber with a circumferential retainer inside. A rib connecting plate is connected to the circumferential retainer. The rib connecting plate is made of shape memory alloy. An electric telescopic rod is distributed at the top of the heating chamber. The lower end of the electric telescopic rod is connected to a shaping rod assembly, which is located directly above the rib connecting plate. The heating chamber is equipped with a controller, which includes a CT image 2D processing module, a 3D reconstruction module, a point cloud matching and path planning module, and a drive signal generation module. The CT image 2D processing module is connected to the input terminal of the 3D reconstruction module, the 3D reconstruction module is connected to the input terminal of the point cloud matching and path planning module, the point cloud matching and path planning module is connected to the input terminal of the drive signal generation module, and the drive signal generation module is electrically connected to the electric telescopic rod and the shaping rod assembly, respectively.

[0006] The above technical solution first imports the patient's chest CT two-dimensional image into the controller. After processing by various modules in the controller, the corresponding drive signals are transmitted to the electric telescopic rod and shaping rod assembly. The electric telescopic rod and shaping rod assembly move to move the rib connecting plate, and finally obtain the molded imitation chest rib piece.

[0007] Preferably, the shaping rod assembly includes a mounting frame connected to the lower end of the electric telescopic rod, on which a shaping rod is rotatably connected in the vertical direction, and an arc-shaped toothed rack is provided on the shaping rod in its axial direction; A first gear is rotatably connected to the mounting frame. The first gear meshes with the arc-shaped rack. The central axis of the first gear is connected to the output shaft of the first motor. The first motor is electrically connected to the drive signal generation module.

[0008] In this scheme, the first motor drives the first gear to rotate, and the first gear drives the arc-shaped rack to move. Since the arc-shaped rack is set on the shaping rod along the axial direction of the shaping rod, it can drive the shaping rod to rotate in the vertical plane during the movement of the arc-shaped rack, so as to achieve the purpose of adjusting the rotation angle of the shaping rod and making the rib connecting plate obtain different degrees of curvature.

[0009] Preferably, the mounting frame is provided with a spherical groove and a limiting opening groove communicating with the spherical groove, the limiting opening groove having a U-shaped structure and being arranged in the vertical direction; The upper end of the shaping rod is movably connected to the spherical groove via a ball, the lower end of the shaping rod extends out of the mounting frame, the arc-shaped rack is provided at the limiting opening groove, and the shaping rod can swing back and forth along the limiting opening groove.

[0010] In this design, when the arc-shaped rack moves, it causes the sphere of the shaping rod to move within the spherical groove of the mounting frame. Since the arc-shaped rack is located at the limiting opening groove and the limiting opening groove is connected to the spherical groove, the shaping rod can only move along the limiting opening groove.

[0011] Preferably, the upper end of the electric telescopic rod is connected to the heating box via a rotary table, the fixed part of the rotary table is connected to the heating box, the rotating part of the rotary table is connected to the electric telescopic rod, and the driving part of the rotary table is electrically connected to the driving signal generation module.

[0012] In this design, the rotating table drives the electric telescopic rod and the shaping rod assembly to rotate synchronously, and then shapes the rib connecting plate. This allows for shaping of the rib connecting plate in all directions, resulting in a better shaping effect.

[0013] Preferably, the heating chamber is provided with a lifting mechanism, which includes a fixed frame disposed in the heating chamber, a second gear rotatably connected to the fixed frame, the second gear being driven by a second motor, a movable rack movably connected to the fixed frame in the vertical direction, the movable rack meshing with the second gear, a support plate connected to the upper end of the movable rack in the horizontal direction, and the circumferential device connected to the support plate.

[0014] The design incorporates a lifting mechanism to facilitate the installation and removal of the circumferential clamp and rib connecting plate. In practice, the second motor drives the second gear to rotate, which in turn drives the moving rack to move up and down, thus raising and lowering the support plate.

[0015] Preferably, the rib connecting plate is provided with at least one set of hairpin assemblies. The hairpin assembly includes connecting blocks symmetrically arranged on both sides of the rib connecting plate. A left gear is rotatably connected to a connecting block on the left side. The left gear meshes with a left arc-shaped rack. The left arc-shaped rack is slidably connected to the connecting block on that side. A right gear is rotatably connected to a connecting block located on the right side. This right gear meshes with a right-side arc-shaped rack. The right-side arc-shaped rack is slidably connected to the connecting block on that side. The left-side arc-shaped rack is arranged opposite to the right-side arc-shaped rack, and either the right-side or left-side arc-shaped rack has a socket. Correspondingly, either the left-side or right-side arc-shaped rack has a insert. During the movement of the right-side and left-side arc-shaped racks, the insert is driven to engage with the socket.

[0016] The design incorporates a hairpin-like component to facilitate the connection between the molded imitation rib piece and the human rib. Specifically, the human rib is positioned between the corresponding left and right arc-shaped toothed racks. The left gear rotates, causing the left arc-shaped toothed rack to slide along the connecting block, while the right gear rotates, causing the right arc-shaped toothed rack to slide along the right connecting block. As the left and right arc-shaped toothed racks move relative to each other, the insert and the insertion hole move synchronously. The insert is then inserted into the insertion hole, connecting the left and right arc-shaped toothed racks and thus linking the human rib with the molded imitation rib piece.

[0017] Preferably, the connecting block is provided with a mounting groove, and sliders are fixed on both sides of the mounting groove. Arc-shaped grooves are provided on both sides of the right arc-shaped rack and the left arc-shaped rack, and the sliders are slidably connected to the arc-shaped grooves.

[0018] In this design, the slider is fixed to the connecting block. When the left or right arc-shaped rack moves, the arc groove on it slides with the slider to achieve the movement of the left and right arc-shaped racks relative to the connecting block.

[0019] Preferably, the top of the heating box is provided with two Y-axis slide rails, and an X-axis slide rail is slidably connected to the Y-axis slide rails via a Y-axis slider. The rotary table is slidably connected to the X-axis slide rails via an X-axis slider.

[0020] This solution, through the setting of X-axis slide rails and X-axis sliders, enables the adjustment of the X-axis position of the rotary table, electric telescopic rod, and shaping rod, while the setting of Y-axis slide rails and Y-axis sliders enables the adjustment of the Y-axis position of the rotary table, electric telescopic rod, and shaping rod. This allows the shaping rod to accurately match different rib connection plates and adapt to individual differences.

[0021] A method for forming a simulated rib cage, using the aforementioned simulated rib cage forming device, includes the following steps: S1, acquire the patient's CT two-dimensional tomographic image; S2, the CT image two-dimensional processing module processes the patient's CT two-dimensional tomographic image to obtain the two-dimensional coordinates of the rib contour points of each tomographic layer; S3, the three-dimensional reconstruction module processes the two-dimensional coordinates of the rib contour points of each fracture layer to obtain the target point cloud coordinates of the rib. S4, the point cloud matching and path planning module converts the acquired target point cloud of the rib into motion parameters of the rotary table, the shaping rod assembly, and the electric telescopic rod. , , ); θ is the rotation angle of the rotary table, φ is the rotation angle of the shaping rod assembly, and s is the displacement of the electric telescopic rod; This step specifically includes: S41, input the target point cloud coordinates of the rib and the source point cloud coordinates of the rib connecting plate into the point cloud matching and path planning module; S42, based on the coordinates of the two endpoints of the rib, the source point cloud coordinate data of the rib connecting plate is aligned with the target point cloud coordinate data of the rib. Then, a constrained ICP algorithm is used to compare the source point cloud coordinate data of the two endpoints of the rib with the target point cloud coordinate data of the rib, with the endpoint error ≤0.5mm as a constraint. Then, the rotation matrix and translation vector are iteratively optimized according to the curvature, length, and endpoints of the rib. The comparison is continuously carried out in each iteration to bring the average distance error between the source point cloud coordinate data and the target point cloud coordinate data to <0.8mm. The average distance refers to the Euclidean distance from each point in the source point cloud to the nearest corresponding point in the target point cloud. The average distance is obtained by calculating the sum of the distances of all corresponding points and dividing by the total number of points. After the alignment of the source point cloud and the target point cloud of the rib connecting plate is completed, the matching curve is decomposed into multiple concentric arcs, and multiple key control points are generated in each layer. S43, finally, the key control points are converted into motion parameters using the following conversion formula: ; ; ; S44, output the motion parameters of the rotary table, the shaping rod assembly, and the electric telescopic rod. , , (to the drive signal generation module); S5, the drive signal generation module acquires the motion parameters of the rotary table, the shaping rod assembly, and the electric telescopic rod. , , The signal is converted into a drive signal for the rotary table, the shaping rod assembly, and the electric telescopic rod, which directly controls the movement of the rotary table, the shaping rod assembly, and the electric telescopic rod. S6, to obtain the molded imitation chest rib piece.

[0022] Preferably, the control system of the controller further includes a real-time error correction module. The output of the three-dimensional reconstruction module is connected to the real-time error correction module, and the real-time error correction module is connected to the input of the drive signal generation module. A miniature camera is installed inside the heating chamber. The miniature camera acquires the measured shape of the shaped rib connecting plate in real time and transmits the corresponding signal to the real-time error correction module after conversion. The real-time error correction module transmits the measured shape of the shaped rib connecting plate, the drive signal obtained after correction of the target point cloud coordinate data, and the final shaping result to the rotary table, the shaping rod assembly, and the electric telescopic rod.

[0023] Compared with existing technologies, the advantages of this invention are as follows: This invention enables surgery to be performed immediately even before the 3D-printed permanent implant is completed. The patient's own respiratory function is maintained by using a simulated rib piece made with the device of this invention to replace the incomplete 3D-printed part, avoiding delays in treatment due to waiting time for printing (usually 1-3 weeks). This is particularly suitable for emergency or rapidly progressing cancer patients. Furthermore, the device of this invention can transmit corresponding drive signals to the electric telescopic rod and shaping rod assembly after processing by various modules within the controller based on the patient's two-dimensional chest CT image. The electric telescopic rod and shaping rod assembly move the rib connecting plate, ultimately obtaining a molded simulated rib piece with precise and rapid shaping and good results. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 A schematic diagram of the molding components in the diagram; Figure 3 for Figure 2 A schematic diagram of the structure of the shaping rod assembly; Figure 4 for Figure 3A schematic diagram of the mounting bracket in the diagram; Figure 5 for Figure 3 A schematic diagram of the structure of the shaping rod in the middle; Figure 6 for Figure 1 A schematic diagram of the rib connection plate in the middle; Figure 7 for Figure 6 A schematic diagram of the structure of the hairpin assembly in the image; Figure 8 for Figure 7 A schematic diagram of the internal connection state of the hairpin component in the image; Figure 9 for Figure 1 A schematic diagram of the lifting mechanism in the diagram; Figure 10 for Figure 9 A schematic diagram of the internal structure of the lifting mechanism in the diagram; Figure 11 for Figure 1 Internal circuit connection diagram of the controller in the diagram; Figure 12 A schematic diagram of the rib connecting plate after molding according to the present invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0026] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] When a patient urgently needs surgery, but the 3D-printed rib cage is not yet complete, the rib cage modeled by this invention can be temporarily installed on the patient's sternum (i.e., the first surgery), allowing the patient to breathe normally. Once the 3D-printed rib cage is complete, a second surgery is performed to remove the rib cage model and install the 3D-printed rib cage.

[0028] As attached Figure 1 - Appendix Figure 11The illustrated rib-simulating molding device includes a heating chamber 1, which is rectangular. The front panel 11 of the rectangular chamber can be rotated to open the chamber, and a handle 12 is provided on the front panel 11 for easy pulling to open the heating chamber 1. The heating chamber 1 contains a heating module 13, which can be a heater or an electric heating wire, etc.

[0029] refer to Figure 9 and Figure 10 The heating chamber 1 is equipped with a lifting mechanism 6. The lifting mechanism 6 includes a fixed frame 61 located inside the heating chamber 1. The fixed frame 61 has two sets of lifting components. Each lifting component includes a second gear 62 rotatably connected to the fixed frame 61. The second gear 62 is driven by a second motor 63, which is mounted on the fixed frame 61. A movable rack 64 is movably connected to the fixed frame 61 in the vertical direction. The movable rack 64 meshes with the second gear 62. The two movable racks 64 are connected by a connecting rod 68. The upper ends of the two movable racks 64 are connected to a support plate 67 in the horizontal direction. A retainer 7 is connected to the support plate 67.

[0030] Specifically, a slide groove 610 is provided on the fixed frame 61 along the vertical direction, and support rods 65 are provided on both sides of the moving rack 64. A limiting slider 66 is provided on the support rod 65, and the limiting slider 66 slides in cooperation with the slide groove 610.

[0031] A rib connecting plate 8 is connected to the circumferential retainer 7. One end of the rib connecting plate 8 is connected to the circumferential retainer 7, and the other end is suspended. A cooling and heating module 80 is provided on the rib connecting plate 8. The rib connecting plate 8 is made of shape memory alloy. Relying on the shape memory effect of the shape memory alloy, when the temperature is <45℃, the rib connecting plate 8 is flexibly molded into a rib-like structure under the action of the molding component. When the temperature is high, it can automatically return to its initial shape without plastic deformation.

[0032] The end of the rib connecting plate 8 is provided with a spring mounting hole 81. After successful shaping, when it is installed into the patient's body, a constant force spring is installed in the spring mounting hole 81 on the two opposite rib connecting plates 8 to provide elastic support during temporary use: the constant force spring adapts to expansion and contraction during breathing, increasing the thoracic volume and improving vital capacity.

[0033] refer to Figure 6 , Figure 7 and Figure 8At least one set of hairpin assemblies 9 are distributed along the length of the rib connecting plate 8. Each hairpin assembly 9 includes connecting blocks 92 symmetrically arranged on both sides of the rib connecting plate 8. A left gear 95 is rotatably connected to a connecting block 92 on the left side. The left gear 95 is driven by a left motor 97, which is mounted on the connecting block 92. The left gear 95 meshes with a left arc-shaped rack 93, and the left arc-shaped rack 93 is slidably connected to the connecting block 92 on that side. A right gear 96 is rotatably connected to a connecting block 92 located on the right side. The right gear 96 is driven by a right motor 98, which is mounted on the right connecting block 92. The right gear 96 meshes with a right arc-shaped rack 94, which is slidably connected to the connecting block 92 on that side. A left arc-shaped rack 93 is positioned opposite to the right arc-shaped rack 94, and one end of the right arc-shaped rack 94 or one end of the left arc-shaped rack 93 is provided with a insertion hole 990. Correspondingly, an insertion strip 991 is provided on the end of the left arc-shaped rack 93 or the right arc-shaped rack 94 near the insertion hole 990. During the movement of the right arc-shaped rack 94 and the left arc-shaped rack 93, the insertion strip 991 is synchronously driven to engage with the insertion hole 990.

[0034] The connecting block 92 is provided with a mounting groove 920. The right arc-shaped rack 94 and the left arc-shaped rack 93 are respectively movably installed in the mounting groove 920 on the corresponding side of the connecting block 92. A slider 921 is fixed on both sides of the mounting groove 920. The right arc-shaped rack 94 and the left arc-shaped rack 93 are respectively provided with arc-shaped grooves 941 and 931 on both sides. The slider 921 is slidably connected to the arc-shaped grooves 941 and 931.

[0035] In this embodiment, in order to match the length of ribs of different lengths, lead screws 91 are provided on both sides of the rib connecting plate 8. The lead screws 91 extend along the length direction of the rib connecting plate 8, and the connecting block 92 is slidably connected to the lead screw 91 through the lead screw slider. In order to facilitate shaping and bending together with the rib connecting plate 8, the lead screw 91 in this embodiment is made of shape memory alloy.

[0036] In this embodiment, the length direction of the rib connecting plate 8 in the initial state is defined as the X direction, the width direction of the rib connecting plate 8 as the Y direction, and the extension direction of the electric telescopic rod 4 as the Z direction. The rotating table 41 rotates in the XOY plane, and the shaping rod 54 rotates in the XOZ plane.

[0037] refer to Figure 2The heating chamber 1 has two Y-axis slide rails 2 at its top. Multiple X-axis slide rails 3 are slidably connected to these Y-axis slide rails 2 via Y-axis sliders. Multiple rotating platforms 41 are slidably connected to the X-axis slide rails 3 via X-axis sliders. The number of X-axis slide rails is the same as the number of rib connecting plates 8. The fixed part of each rotating platform 41 is connected to the X-axis slider, and the rotating part of each rotating platform 41 is connected to the upper end of the electric telescopic rod 4. The driving part of each rotating platform 41 is electrically connected to the controller 10, specifically to the drive signal generation module 104 on the controller 10. The driving part of each rotating platform 41 is capable of receiving sine wave signals.

[0038] In this embodiment, one rib connecting plate 8 corresponds to four electric telescopic rods 4. The four electric telescopic rods 4 are distributed in two groups above the rib connecting plate 8. Of course, only two can be set. The specific choice depends on the actual situation. The driving part of the electric telescopic rod 4 can receive PWM signals.

[0039] refer to Figure 3 , Figure 4 and Figure 5 A shaping rod assembly 5 is connected to the lower end of each electric telescopic rod 4, and the shaping rod assembly 5 is located directly above the rib connecting plate 8.

[0040] The shaping rod assembly 5 includes a mounting frame 51 connected to the lower end of the electric telescopic rod 4. A shaping rod 54 is rotatably connected to the mounting frame 51 in the vertical direction. An arc-shaped rack 55 is provided on the shaping rod 54 in the axial direction. A first gear 56 is rotatably connected to the mounting frame 51. The central axis of the first gear 56 is parallel to the horizontal plane. The first gear 56 meshes with the arc-shaped rack 55. The central axis of the first gear 56 is connected to the output shaft of the first motor 57. The first motor 57 is mounted on the mounting frame 51. The first motor 57 is electrically connected to the drive signal generation module 104 of the controller 10, and the first motor 57 can receive square wave pulse signals.

[0041] Specifically, the mounting frame 51 is provided with a spherical groove 52 and a limiting opening groove 53 communicating with the spherical groove 52. The limiting opening groove 53 has a U-shaped structure and is arranged in the vertical direction. The upper end of the shaping rod 54 is movably connected to the spherical groove 52 via a ball 541. The lower end of the shaping rod 54 extends out of the mounting frame 51. The lower end of the shaping rod 54 has a spherical structure. An arc-shaped rack mounting part 542 is provided on the ball 541. An arc-shaped rack 55 is connected to the arc-shaped rack mounting part 542. The arc-shaped rack 55 is located at the limiting opening groove 53. The shaping rod 54 can swing back and forth along the limiting opening groove 53.

[0042] refer to Figure 11The heating chamber 1 is equipped with a controller 10, which includes a CT image two-dimensional processing module 101, a three-dimensional reconstruction module 102, a point cloud matching and path planning module 103, and a drive signal generation module 104. The CT image two-dimensional processing module 101 is connected to the input end of the three-dimensional reconstruction module 102, the three-dimensional reconstruction module 102 is connected to the input end of the point cloud matching and path planning module 103, the point cloud matching and path planning module 103 is connected to the input end of the drive signal generation module 104, and the drive signal generation module 104 is electrically connected to the electric telescopic rod 4, the shaping rod assembly 5, and the rotary table 41.

[0043] In this embodiment, multiple miniature cameras are provided inside the heating box 1. The multiple miniature cameras are electrically connected to the controller 10. The multiple miniature cameras can collect the measured shape of the rib connecting plate 8 after shaping from different angles in real time and transmit the corresponding signals to the real-time error correction module 105 of the controller 10 after conversion.

[0044] The output of the three-dimensional reconstruction module 102 is connected to the input of the real-time error correction module 105. The output of the real-time error correction module 105 is connected to the input of the drive signal generation module 104. The real-time error correction module 105 transmits the measured shape of the shaped rib connecting plate, the drive signal obtained after correction of the target point cloud coordinate data, and the final shaping result to the rotary table 41, the shaping rod assembly 5, and the electric telescopic rod 4.

[0045] Using the rib-simulating forming device shown in the attached figure, a method for forming rib-simulating breast bones is designed, including the following steps: S1, acquire the patient's CT two-dimensional tomographic image; These 2D CT images are acquired by scanning the chest with a CT (computed tomography) scanner and then processing the data. This processing involves a computer processing massive amounts of raw projection data, using a "back-projection algorithm" (or a more advanced iterative reconstruction algorithm) to calculate the X-ray attenuation coefficient of each "voxel" (the smallest unit in three-dimensional space) in the chest. The attenuation coefficients of voxels within the same slice (e.g., a horizontal section) are then converted into grayscale values—the higher the attenuation coefficient (e.g., ribs), the higher the grayscale value (bright white); the lower the attenuation coefficient (e.g., lungs), the lower the grayscale value (black). This ultimately generates a series of continuous 2D tomographic images (each corresponding to a scanning slice), arranged continuously between layers to fully present the anatomical structure of the chest from superficial to deep. S2, the CT image two-dimensional processing module 101 processes the patient's CT two-dimensional tomographic image to obtain the two-dimensional coordinates of the rib contour points of each tomographic layer; This step specifically includes: First, the aforementioned CT two-dimensional tomographic images are received, and each image is then processed using... Gaussian filtering removes noise while preserving rib edge details; Next, the high-density rib region of each CT two-dimensional tomographic image is segmented with a threshold of 250HU to separate the high-density rib region from the surrounding soft tissue and obtain the segmented connected regions (multiple regions composed of adjacent pixels). Because small connected regions are often artifacts caused by small calcifications, noise interference, etc. Therefore, the area was subsequently selected based on a screening area > 100mm. 2 By eliminating artifacts such as small calcifications from the connected regions and retaining the main rib area, the processed rib area is obtained. Finally, the Sobel operator (edge ​​detection algorithm) is used to extract the edges of the processed rib region. By calculating the horizontal and vertical coordinates of the edge points in the image, two-dimensional coordinates of the rib contour points corresponding to each tomographic image are generated (data format is (x pixel, y pixel, layer number)). S3, the three-dimensional reconstruction module 102 processes the two-dimensional coordinates of the rib contour points of each fracture layer to obtain the target point cloud coordinates of the rib. This step specifically includes: First, inter-layer registration is performed based on the centroid coordinates between the rib contours of adjacent slices, with a centroid distance of <5mm as a constraint to ensure the alignment of each fault position. The rib contours of the aligned slices are then stacked along the Z-axis (fault depth direction), and a three-dimensional mesh model is constructed using the voxel stitching method. Finally, point cloud data containing spatial coordinate information is generated by uniformly sampling from the surface of the 3D mesh model at 1mm intervals. The final output is the target point cloud coordinates of the rib (data format: (x, y, z), containing 10...). 4 -10 5 (points); S4, the point cloud matching and path planning module 103 converts the acquired target point cloud coordinates of the rib into motion parameters of the rotary table 41, the shaping rod assembly 5, and the electric telescopic rod 4. , , ); θ is the rotation angle of the rotary table 41, φ is the rotation angle of the shaping rod assembly 5, and s is the displacement of the electric telescopic rod 4; This step specifically includes: S41, input the target point cloud coordinates of the rib and the source point cloud coordinates of the rib connecting plate into the point cloud matching and path planning module 103; S42, based on the coordinates of the two endpoints of the rib, the source point cloud coordinate data of the rib connecting plate is aligned with the target point cloud coordinate data of the rib. Then, a constrained ICP algorithm is used to compare the source point cloud coordinate data of the two endpoints of the rib with the target point cloud coordinate data of the rib, with the error of the two endpoints ≤0.5mm as a constraint. Then, the rotation matrix and translation vector are iteratively optimized according to the curvature, length, and endpoints of the rib. The comparison is continuously carried out in each iteration to make the average distance error between the source point cloud coordinate data and the target point cloud coordinate data converge to <0.8mm. The average distance refers to the Euclidean distance from each point in the source point cloud to the nearest corresponding point in the target point cloud. The average distance is obtained by calculating the sum of the distances of all corresponding points and dividing by the total number of points. After the alignment of the source point cloud coordinates and the target point cloud coordinates of the rib connecting plate is completed, the matching curve is decomposed into multiple concentric arcs, and multiple key control points are generated in each layer. S43, finally, the key control points are converted into motion parameters using the following conversion formula: ; ; ; S44, output the motion parameters of the rotary table 41, the shaping rod assembly 5, and the electric telescopic rod 4. , , (to the drive signal generation module 104); Formula derivation process: In a Cartesian coordinate system, let the projected coordinates of the control point on the horizontal plane be ( ). , The rotation center of the rotary table is the origin of the coordinate system. , According to the definition of the tangent function in trigonometric functions, in a right triangle, the ratio of an opposite side to an adjacent side is equal to the tangent of that angle. The rotation angle of the rotating platform... Used to adjust the rotation angle within a plane. To obtain the angle value, it is calculated using the arctangent function, i.e. In fields such as robot motion control and robotic arm positioning, similar coordinate relationships are often used to calculate the horizontal rotation angle. The three-dimensional coordinates of the control point are ( , , ), (Controlling the tilt of the space), consider the shaping rod as the hypotenuse of a right triangle, and the coordinates of the control point in the vertical direction are... In a spatial rectangular coordinate system, In the right triangle containing the sine function, according to the definition of the sine function, the sine value is equal to the ratio of the opposite side to the hypotenuse. To solve... Taking the arcsine function of both sides of the equation, we get... In scenarios such as spatial attitude control and joint angle calculation, the spatial tilt angle is often determined based on such trigonometric function relationships. Displacement of electric telescopic pole According to the formula for the distance between two points in three-dimensional space, the spatial distance from the control point to the origin is: Considering that the material will deform during the shaping process, a shape memory alloy deformation coefficient is introduced. The actual displacement is corrected, therefore the displacement of the electric telescopic pole is... In fields involving displacement control and material deformation, such as material forming and machining, it is often necessary to make similar corrections to theoretical calculation results based on specific material properties; shape memory metal deformation coefficient Determination: Under standard experimental conditions, different degrees of external force were applied to shape memory alloy samples from the same batch to induce deformation, and the magnitude of the external force, the amount of deformation, and the temperature change data were recorded. When the temperature returned to the shape memory alloy's phase transition temperature, the dimensions of the material after recovery were measured. Through fitting multiple experimental data, the deformation coefficient of the shape memory alloy was finally determined. The value; S5, the drive signal generation module 104 acquires the motion parameters of the rotary table 41, the shaping rod assembly 5, and the electric telescopic rod 4. , , The signal is converted into a drive signal for the rotary table 41, the shaping rod assembly 5, and the electric telescopic rod 4, and the controller 10 directly controls the operation of the rotary table 41, the shaping rod assembly 5, and the electric telescopic rod 4. This step specifically includes: The drive signal generation module 104 receives motion parameters output by the rotary table 41 / shaping rod assembly 5 / electric telescopic rod 4. , , These parameters determine the specific characteristics of the signal, for example: A 50Hz sine wave signal is generated for the rotary table 41, the signal amplitude of which is related to the rotation angle. Proportional to the voltage, ranging from 0 to 3V, to ensure smooth rotation; For the shaping rod assembly 5, a 200Hz square wave pulse signal is generated, with the number of pulses and angle... Relatedly, every 10 pulses correspond to a 1° rotation angle, ensuring the accuracy of angle adjustment; For the electric telescopic pole 4, generate a PWM signal; S6, to obtain the molded imitation chest rib piece; This step specifically includes: Real-time error correction: The miniature camera converts the measured shape data of the shaped rib connecting plate and inputs it into the target point cloud coordinate data obtained by the 3D reconstruction module 102 into the real-time error correction module 105. First, the measured shape of the shaped rib connecting plate is converted and compared with the shape of the target point cloud coordinates. The local deviation value between the two is calculated. If the local deviation value is greater than 0.8mm, the parameter adjustment stage is entered. The corrected drive signal is fed back to the drive signal generation module 104, and then the action of the rotary table 41, electric telescopic rod 4 and shaping rod assembly 5 is controlled again through the signal to complete the plasticization of the rib connecting plate 8. If the deviation is not greater than 0.8mm, the final shaping result is output to obtain the molded imitation chest rib part.

[0046] The preferred embodiments of the present invention have been described above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A device for forming ribs and sternum, characterized in that: The heating box (1) includes a heating chamber (1) with a ring (7) inside. A rib connecting plate (8) is connected to the ring (7). The rib connecting plate (8) is made of shape memory alloy. An electric telescopic rod (4) is distributed at the top inside the heating chamber (1). The lower end of the electric telescopic rod (4) is connected to a shaping rod assembly (5). The shaping rod assembly (5) is located directly above the rib connecting plate (8). The heating box (1) is equipped with a controller (10). The controller (10) includes a CT image two-dimensional processing module (101), a three-dimensional reconstruction module (102), a point cloud matching and path planning module (103), and a drive signal generation module (104). The CT image two-dimensional processing module (101) is connected to the input end of the three-dimensional reconstruction module (102). The three-dimensional reconstruction module (102) is connected to the input end of the point cloud matching and path planning module (103). The point cloud matching and path planning module (103) is connected to the input end of the drive signal generation module (104). The drive signal generation module (104) is electrically connected to the electric telescopic rod (4) and the shaping rod assembly (5) respectively.

2. The rib-simulating molding device according to claim 1, characterized in that: The shaping rod assembly (5) includes a mounting frame (51) connected to the lower end of the electric telescopic rod (4), on which a shaping rod (54) is rotatably connected in the vertical direction, and an arc-shaped toothed rack (55) is provided on the shaping rod (54) in the axial direction. A first gear (56) is rotatably connected to the mounting frame (51). The first gear (56) meshes with the arc-shaped rack (55). The central axis of the first gear (56) is connected to the output shaft of the first motor (57). The first motor (57) is electrically connected to the drive signal generation module (104).

3. The rib-simulating molding device according to claim 2, characterized in that: The mounting frame (51) is provided with a spherical groove (52) and a limiting opening groove (53) communicating with the spherical groove (52). The limiting opening groove (53) has a U-shaped structure and is set in the vertical direction. The upper end of the shaping rod (54) is movably connected to the spherical groove (52) through a ball (541), the lower end of the shaping rod (54) extends out of the mounting frame (51), the arc-shaped rack (55) is provided at the limiting opening groove (53), and the shaping rod (54) can swing back and forth along the limiting opening groove (53).

4. The rib-simulating molding device according to claim 2, characterized in that: The upper end of the electric telescopic rod (4) is connected to the heating box (1) via a rotating platform (41). The fixed part of the rotating platform (41) is connected to the heating box (1), the rotating part of the rotating platform (41) is connected to the electric telescopic rod (4), and the driving part of the rotating platform (41) is electrically connected to the driving signal generation module (104).

5. The rib-simulating molding device according to claim 4, characterized in that: The heating box (1) is equipped with a lifting mechanism (6). The lifting mechanism (6) includes a fixed frame (61) located inside the heating box (1). A second gear (62) is rotatably connected to the fixed frame (61). The second gear (62) is driven by a second motor (63). A movable rack (64) is movably connected to the fixed frame (61) in the vertical direction. The movable rack (64) meshes with the second gear (62). A support plate (67) is connected to the upper end of the movable rack (64) in the horizontal direction. The circumferential device (7) is connected to the support plate (67).

6. The rib-simulating molding device according to claim 4, characterized in that: At least one set of hairpin assemblies (9) are provided on the rib connecting plate (8). The hairpin assembly (9) includes connecting blocks (92) symmetrically arranged on both sides of the rib connecting plate (8). A left gear (95) is rotatably connected to a connecting block (92) on the left side. The left gear (95) meshes with a left arc-shaped rack (93). The left arc-shaped rack (93) is slidably connected to the connecting block (92) on that side. A right gear (96) is rotatably connected to a connecting block (92) on the right side. The right gear (96) meshes with a right arc-shaped rack (94). The right arc-shaped rack (94) is slidably connected to the connecting block (92) on the same side. The left arc-shaped rack (93) is arranged opposite to the right arc-shaped rack (94). The right arc-shaped rack (94) or the left arc-shaped rack (93) is provided with a socket (990). Correspondingly, the left arc-shaped rack (93) or the right arc-shaped rack (94) is provided with a strip (991). During the movement of the right arc-shaped rack (94) and the left arc-shaped rack (93), the strip (991) is driven to engage with the socket (990).

7. The rib-simulating forming device according to claim 6, characterized in that: The connecting block (92) is provided with an installation groove (920), and sliders (921) are fixed on both sides of the installation groove (920). The right arc-shaped rack (94) and the left arc-shaped rack (93) are respectively provided with arc-shaped grooves (941, 931) on both sides. The sliders (921) are slidably connected to the arc-shaped grooves (941, 931).

8. The rib-simulating molding device according to claim 7, characterized in that: The top of the heating box (1) is provided with two Y-axis slide rails (2), and an X-axis slide rail (3) is slidably connected to the Y-axis slide rail (2) via a Y-axis slider. The rotary table (41) is slidably connected to the X-axis slide rail (3) via an X-axis slider.

9. A method for forming a simulated rib cage, characterized in that, The rib-forming device according to any one of claims 4-8 includes the following steps: S1, acquire the patient's CT two-dimensional tomographic image; S2, the CT image two-dimensional processing module (101) processes the patient's CT two-dimensional tomographic image to obtain the two-dimensional coordinates of the rib contour points of each tomographic layer; S3, the three-dimensional reconstruction module (102) processes the two-dimensional coordinates of the rib contour points of each fracture to obtain the target point cloud coordinates of the rib; S4, the point cloud matching and path planning module (103) converts the acquired target point cloud coordinates of the rib into motion parameters of the rotary table (41), the shaping rod assembly (5), and the electric telescopic rod (4). , , ); θ is the rotation angle of the rotary table (41), φ is the rotation angle of the shaping rod assembly (5), and s is the displacement of the electric telescopic rod (4); This step specifically includes: S41, input the target point cloud coordinates of the rib and the source point cloud coordinates of the rib connecting plate into the point cloud matching and path planning module (103). S42, based on the coordinates of the two endpoints of the rib, the source point cloud coordinate data of the rib connecting plate is aligned with the target point cloud coordinate data of the rib. Then, a constrained ICP algorithm is used to compare the source point cloud coordinate data of the two endpoints of the rib with the target point cloud coordinate data of the rib, with the error of the two endpoints ≤0.5mm as a constraint. Then, the rotation matrix and translation vector are iteratively optimized according to the curvature, length, and endpoints of the rib. The comparison is continuously carried out in each iteration to make the average distance error between the source point cloud coordinate data and the target point cloud coordinate data converge to <0.8mm. The average distance refers to the Euclidean distance from each point in the source point cloud to the nearest corresponding point in the target point cloud. The average distance is obtained by calculating the sum of the distances of all corresponding points and dividing by the total number of points. After the alignment of the source point cloud coordinates and the target point cloud coordinates of the rib connecting plate is completed, the matching curve is decomposed into multiple concentric arcs, and multiple key control points are generated in each layer. S43, finally, the key control points are converted into motion parameters using the following conversion formula: ； ； ； S44, output the motion parameters of the rotary table (41), the shaping rod assembly (5), and the electric telescopic rod (4). , , ) to the drive signal generation module (104); S5, the drive signal generation module (104) will acquire the motion parameters of the rotary table (41), the shaping rod assembly (5), and the electric telescopic rod (4). , , The signal is converted into a drive signal for the rotary table (41), the shaping rod assembly (5), and the electric telescopic rod (4), which directly controls the operation of the rotary table (41), the shaping rod assembly (5), and the electric telescopic rod (4). S6, to obtain the molded imitation chest rib piece.

10. A method for forming a simulated rib cage, characterized in that: It also includes a real-time error correction module (105). The output end of the three-dimensional reconstruction module (102) is connected to the real-time error correction module (105). The real-time error correction module (105) is connected to the input end of the drive signal generation module (104). A miniature camera is installed inside the heating box (1). The miniature camera collects the measured shape of the shaped rib connecting plate (8) in real time and transmits the corresponding signal to the real-time error correction module (105) after conversion. The real-time error correction module (105) transmits the measured shape of the shaped rib connecting plate (8), the drive signal obtained after correction of the target point cloud coordinate data, and the final shaping result to the rotary table (41), the shaping rod assembly (5), and the electric telescopic rod (4).

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