A method and system for extracting bone cortical information and trabecular architecture characteristics based on plasticized tomographic slices

Abstract

The present invention discloses a method and system for extracting cortical bone information and trabecular bone structure characteristics based on plasticized tomographic slices, which belongs to the field of biomedical engineering technology, including: through polymer material embedding and image processing technology, accurate analysis of cortical bone and trabecular bone structure is achieved. This method not only extracts the thickness, contour and curvature information of the cortical bone, but also deeply reveals the structural characteristics of trabecular bone, providing an unprecedented anatomical perspective for biomechanical research and biomaterial research and development. This innovative method not only enriches the data basis for bone structure research, but also promotes a deep understanding of bone biomechanical mechanisms, opens up a new path for the development of high-performance, highly biocompatible bone implants, and plays an important role in promoting the development of the field of biomaterials.

Description

Technical Field

[0001] The present invention relates to the field of biomedical engineering technology, and more specifically to a method and system for jointly extracting bone cortical information and trabecular structure characteristics based on plasticized tomographic slices. Background Art

[0002] The human skeleton is in a dynamic change throughout life, with certain regularity. The morphology of living bones, including the shape, diameter, length and curvature of the bones, adapts to long-term loads before and after bone maturity. The deformation and rate produced in different parts are different according to the size, mode and location of the strain. At the microscopic level, bones can be divided into cortical bone and cancellous bone. On the one hand, the mechanical properties of bones depend on the characteristics of cortical bone such as thickness and shape, and on the other hand, they are also closely related to factors such as the structural characteristics of cancellous bone (trabecular bone).

[0003] In the current methods, the morphology and quantity of cortical bone and trabecular bone can be measured separately, but no technology has been found to extract the characteristics of cortical bone and the structural characteristics of trabecular bone in the bone. The human skeleton supports and protects the organism through cortical bone and cancellous bone. Studying a single microstructure will not clearly understand the true mechanical properties of bone.

[0004] In addition, the traditional methods of observing bone structure, micro-CT technology, nuclear magnetic resonance technology and hard tissue cutting and grinding technology, all have their own limitations. For example, MRI cannot show the fine structure of trabeculae; Micro-CT can obtain the trabecular structure of a small range, but ignores the characteristics of cortical bone, such as the radius of curvature of the cortical bone contour, the change of the center of the circle and the structural relationship between trabeculae; and hard tissue cutting and grinding technology is too microscopic, making it impossible for observers to observe local structures from a global perspective. At present, there is a lack of technology to achieve the co-analysis of the structural characteristics of cortical bone and trabeculae.

[0005] Therefore, how to provide a method and system that can realize the joint extraction of cortical bone information and trabecular bone structure characteristics is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0006] In view of this, the present invention provides a method and system for jointly extracting cortical bone information and trabecular bone architectural characteristics based on plasticized tomography slices. Through plasticized tomography technology, cortical bone information and trabecular bone architectural characteristics can be obtained more comprehensively and accurately at the same time.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A method for jointly extracting bone cortical information and trabecular bone structure characteristics based on plasticized tomographic slices, comprising:

[0009] S1: embedding a bone section slice made of a polymer material and acquiring an image of the bone section slice;

[0010] S2: importing the image of the bone tomographic slice into a programmable software to extract the bone cortex area and obtain the bone cortex thickness of the bone cortex area;

[0011] S3: fitting the cortical bone region using discrete points by a least squares circle fitting algorithm to obtain the center of curvature of the cortical bone region and the radius of curvature;

[0012] S4: acquiring the curvature radius and the trabecular structure information of the position of the curvature center according to the image of the bone cortical area;

[0013] S5; based on the thickness of the bone cortex, the radius of curvature, the center of curvature and the trabecular structure information, the morphological characteristics of the mutual connection and influence between the bone cortex and the trabeculae are obtained, and based on the obtained morphological characteristics of the mutual connection and influence between the bone cortex and the trabeculae, the bone stress characteristics are analyzed.

[0014] Preferably, the bone section slices prepared by embedding with polymer materials specifically include: selecting an object to be processed, embedding the object to be processed with polymer materials, freezing, dehydrating, defatting, and polymer infiltration to obtain the bone section slices.

[0015] Preferably, obtaining the image of the bone section slice specifically includes: photographing and recording the entire bone section slice using a digital camera.

[0016] Preferably, the S2 specifically includes:

[0017] Import the image of the bone section into a programmable software, and select the bone cortical area by mouse click;

[0018] The thickness of the bone cortex region is calculated according to the built-in scale size of the image of the bone cross-section.

[0019] Preferably, the S3 specifically includes:

[0020] A set of discrete points (xi, yi) are randomly given in the bone cortex area, and according to the equation of the circle (xa) 2 +(yb) 2 =r 2 Calculate the error at each discrete point;

[0021] The optimal parameters are found by minimizing the sum of squared errors so that the error between the fitting circle corresponding to the discrete point and the discrete point is minimized.

[0022] Calculate the average distance between the fitting circle and the discrete points as the error index to obtain the discrete points with the highest fitting degree;

[0023] The corresponding center of curvature and radius of curvature are obtained through the discrete point with the highest fitting degree. Preferably, the trabecular structure information includes: the relationship between the radius of curvature and the running and distribution of the trabecular, and the relationship between the center of curvature and the density of the trabecular.

[0024] On the other hand, the present invention also provides a system for extracting bone cortical information and trabecular architecture characteristics based on plasticized tomographic slices, comprising:

[0025] An image acquisition unit, used for acquiring images of bone fracture slices made by embedding with polymer materials;

[0026] A region extraction unit, used for extracting a bone cortical region based on the image of the bone tomographic slice, and obtaining a bone cortical thickness of the bone cortical region;

[0027] A fitting unit, used for fitting the cortical bone region using discrete points through a least squares fitting circle algorithm to obtain the center of curvature of the cortical bone region and the radius of curvature;

[0028] An information extraction unit, used for acquiring the trabecular structure information of the curvature radius and the position of the curvature center according to the image of the bone cortex area;

[0029] An analysis unit is used to obtain the morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone based on the cortical bone thickness, the curvature radius, the curvature center and the trabecular structure information, and analyze the bone stress characteristics based on the obtained morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone.

[0030] Preferably, the acquisition unit is a digital camera.

[0031] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method and system for jointly extracting cortical bone information and trabecular bone architectural features based on plasticized tomographic slices, and a method for co-analyzing cortical bone information and trabecular bone architectural features based on plasticized tomographic slices, which realizes a more comprehensive and accurate understanding of bone structure, and provides an important anatomical method for biomechanical research and the development of biomaterials; the method for co-analyzing cortical bone information and trabecular bone architectural features based on plasticized tomographic slices enables researchers to more comprehensively and accurately obtain cortical bone thickness information, contour information, such as the changing trend of the center of curvature and the radius of curvature, and jointly observe the architectural characteristics of trabecular bone, analyze the potential biomechanical mechanism of bone, and provide more abundant data for in-depth research on bone structure; further, the co-analysis method of plasticized tomographic slices of the present invention helps to better understand the architectural information of cortical bone and trabecular bone in different positions, and plays an important role in the development of cortical bone-cancellous bone dual-bionic implants with better biocompatibility, which will promote the development of the field of biomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the method provided by the present invention;

[0034] Figure 2 This is a digital image of plasticized cross-sectional bone slices;

[0035] Figure 3 It is the mathematical information of the bone cortex displayed on the plasticized tomographic image;

[0036] Figure 4 This is a schematic diagram of the system structure provided by the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The embodiment of the present invention discloses a method for extracting bone cortical information and trabecular architecture characteristics based on plasticized tomographic slices, referring to Figure 1, the method comprising:

[0039] S1: Bone cross-sections made by embedding with polymer materials and obtaining images of bone cross-sections;

[0040] S2: Import the bone section image into programmable software to extract the bone cortical area and obtain the bone cortical thickness of the bone cortical area;

[0041] S3: The center of the curvature of the cortical bone area is obtained by fitting the discrete points of the cortical bone area using the least squares fitting circle algorithm, and the curvature radius is obtained;

[0042] S4: Obtain the curvature radius and the trabecular construction information at the location of the curvature center based on the image of the cortical bone area; specifically, jointly observe the changing trend of the curvature center and radius, as well as the trabecular construction information at their locations, on the image of the plasticized tomographic slice. Based on step S3: the curvature radius has been displayed through discrete points on the image of the plasticized tomographic slice, and the curvature center can be observed through the intersection of the curvature radius. Just observe the information displayed on the image. Figure 3 As shown, the red rays represent the radius of curvature, and the intersection of the red rays is the position of the center of the curvature circle. Figure 3 Red rays and Figure 2 The course of the trabeculae in the middle bone is consistent, and Figure 2 The dense trabecular area Figure 3 This phenomenon shows that the force in the proximal femoral head of the entire femur is concentrated in the center. This force pattern is consistent with the mathematical information of the femoral head cortex, which is important in telling us how to design a strong structure with the least amount of material.

[0043] S5: Based on the thickness of the cortical bone, the radius of curvature, the center of the curvature and the trabecular structure information, the morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone are obtained, and based on the morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone, the bone stress characteristics are analyzed.

[0044] In the fixation surgery of proximal femoral intertrochanteric fracture, the design of the proximal femoral implant is closely related to the success rate of the surgery. Due to the lack of biomechanical performance information between the proximal femoral cortical bone and the cancellous bone, it is still impossible to design an implant with higher biocompatibility. By using the method of the present invention, the bidirectional structural characteristics of the proximal femoral cortical bone and the cancellous bone can be analyzed, and then an implant with higher biocompatibility can be designed.

[0045] The proximal femoral cortical bone area is obtained through plasticization tomography technology; the center of the curvature of the proximal femur is fitted with discrete points through the least squares circle fitting algorithm to display the radius of curvature; the radius of curvature is observed together with the center of the circle and the trabecular structure information of its position, and this structure information is applied to the design of proximal femoral implants to obtain an implant with bidirectional bionic properties of proximal femoral cortical bone and cancellous bone.

[0046] Furthermore, the bone section slices prepared by embedding with polymer materials specifically include: selecting a healthy object to be treated, embedding the object to be treated with polymer materials, freezing, dehydrating, defatting, and polymer infiltration to obtain the bone section slices.

[0047] Furthermore, obtaining the image of the bone section slice specifically includes: photographing and recording the entire bone section slice with a digital camera.

[0048] In another embodiment, S2 specifically includes:

[0049] The image of the bone section is imported into a programmable software, and the bone cortical area is obtained by clicking with the mouse; the programmable software may be MATLAB, etc., and the contour information of the slice image, i.e. the bone cortical area, is calculated for the image in S1 through program writing, or the bone cortical area is accurately selected by selecting a point through the real-time position of the mouse.

[0050] The thickness of the cortical bone area is calculated based on the built-in scale size of the bone tomographic slice image. During the process of taking pictures of the plasticized tomographic slices, a scale bar is marked, and the actual size (such as Figure 2 The thickness of the bone cortex can be used to find out the parts where the load is dispersed or concentrated (the thicker the bone cortex, the stronger the load, and the thinner the bone cortex, the weaker the load). The sparse and dense areas of the trabeculae can be observed and compared to analyze the real mechanical characteristics of the bone.

[0051] In another embodiment, S3 specifically includes:

[0052] Given a set of discrete points (xi, yi) randomly, according to the equation of the circle (xa) 2 +(yb) 2 =r 2 Calculate the error of each discrete point, where (a, b) is the coordinate of the center of the circle and r is the radius of the circle;

[0053] The optimal parameters are found by minimizing the sum of squared errors so that the error between the fitting circle corresponding to the discrete point and the discrete point is minimized.

[0054] Calculate the average distance between the fitting circle and the discrete points as the error index to obtain the discrete points with the highest fitting degree;

[0055] The corresponding curvature center and curvature radius are obtained through the discrete point with the highest fitting degree.

[0056] Preferably, the trabecular structure information includes: the relationship between the radius of curvature and the running and distribution of the trabeculae, and the relationship between the center of curvature and the density of the trabeculae.

[0057] On the other hand, the present invention also provides a system for extracting bone cortical information and trabecular architecture characteristics based on plasticized tomographic slices, such as Figure 4 As shown, including:

[0058] An image acquisition unit, used for acquiring images of bone fracture slices made by embedding with polymer materials;

[0059] A region extraction unit, used for extracting a bone cortical region based on an image of a bone tomographic slice, and obtaining a bone cortical thickness of the bone cortical region;

[0060] A fitting unit is used to obtain the center of the curvature of the cortical bone region by using a least squares fitting circle algorithm to fit the cortical bone region using discrete points, and to obtain the curvature radius;

[0061] An information extraction unit, used for acquiring the trabecular structure information of the curvature radius and the location of the curvature center according to the image of the bone cortex area;

[0062] The analysis unit is used to obtain the morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone based on the cortical bone thickness, curvature radius, curvature center and trabecular structure information, and analyze the bone stress characteristics based on the obtained morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone.

[0063] Furthermore, the acquisition unit is a digital camera.

[0064] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0065] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for extracting cortical bone information and trabecular bone structure characteristics based on plasticized tomographic slices, characterized in that: include: S1: embedding a bone section slice made of a polymer material and acquiring an image of the bone section slice; S2: importing the image of the bone tomographic slice into a programmable software to extract the bone cortex area and obtain the bone cortex thickness of the bone cortex area; S3: fitting the cortical bone region using discrete points by least squares circle fitting algorithm to obtain the center of curvature of the cortical bone region and the radius of curvature; specifically including: A set of discrete points (xi, yi) are randomly given in the bone cortex area, and according to the equation of the circle (xa) 2 +(yb) 2 =r 2 Calculate the error at each discrete point; The optimal parameters are found by minimizing the sum of squared errors so that the error between the fitting circle corresponding to the discrete point and the discrete point is minimized. Calculate the average distance between the fitting circle and the discrete points as an error indicator to obtain the discrete points with the highest fitting degree; Obtain the corresponding curvature center and curvature radius through the discrete point with the highest fitting degree; S4: acquiring the curvature radius and the trabecular structure information of the position of the curvature center according to the image of the bone cortical area; S5; based on the thickness of the bone cortex, the radius of curvature, the center of curvature and the trabecular structure information, the morphological characteristics of the mutual connection and influence between the bone cortex and the trabeculae are obtained, and based on the obtained morphological characteristics of the mutual connection and influence between the bone cortex and the trabeculae, the bone stress characteristics are analyzed.

2. The method for extracting bone cortical information and trabecular bone structure characteristics based on plasticized tomographic slices according to claim 1, characterized in that: The bone section slices prepared by polymer material embedding specifically include: selecting an object to be processed, embedding the object to be processed with a polymer material, freezing, dehydrating, defatting, and polymer infiltration to obtain the bone section slices.

3. The method for extracting bone cortical information and trabecular bone structure characteristics based on plasticized tomographic slices according to claim 1, characterized in that: Acquiring the image of the bone section slice specifically includes: photographing and recording the entire bone section slice using a digital camera.

4. The method for extracting cortical bone information and trabecular bone structure characteristics based on plasticized tomographic slices according to claim 3, characterized in that: The S2 specifically includes: Import the image of the bone section into a programmable software, and select the bone cortical area by mouse click; The thickness of the bone cortex region is calculated according to the built-in scale size of the image of the bone cross-section.

5. The method for extracting bone cortical information and trabecular bone structure characteristics based on plasticized tomographic slices according to claim 1, characterized in that: The trabecular structure information includes: the relationship between the radius of curvature and the running and distribution of the trabeculae, and the relationship between the center of curvature and the density of the trabeculae.

6. A system for extracting cortical bone information and trabecular bone structure characteristics based on plasticized tomographic slices, characterized in that: include: An image acquisition unit, used for acquiring images of bone fracture slices made by embedding with polymer materials; A region extraction unit, used for extracting a bone cortical region based on the image of the bone tomographic slice, and obtaining a bone cortical thickness of the bone cortical region; A fitting unit is used to obtain the center of curvature of the cortical bone region and the radius of curvature by using a least squares fitting circle algorithm to fit the cortical bone region using discrete points; specifically comprising: A set of discrete points (xi, yi) are randomly given in the bone cortex area, and according to the equation of the circle (xa) 2 +(yb) 2 =r 2 Calculate the error at each discrete point; The optimal parameters are found by minimizing the sum of squared errors so that the error between the fitting circle corresponding to the discrete point and the discrete point is minimized. Calculate the average distance between the fitting circle and the discrete points as an error indicator to obtain the discrete points with the highest fitting degree; Obtain the corresponding curvature center and curvature radius through the discrete point with the highest fitting degree; An information extraction unit, used for acquiring the trabecular structure information of the curvature radius and the position of the curvature center according to the image of the bone cortex area; An analysis unit is used to obtain the morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone based on the cortical bone thickness, the curvature radius, the curvature center and the trabecular structure information, and analyze the bone stress characteristics based on the obtained morphological characteristics of the mutual connection and influence between the cortical bone and the trabecular bone.

7. The system for extracting bone cortical information and trabecular bone structure characteristics based on plasticized tomographic slices according to claim 6, characterized in that: The acquisition unit is a digital camera.

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