Simulated physiological load loading device and system

Abstract

The invention relates to the technical field of biomechanics, in particular to an imitated physiological load loading device and system. The simulated physiological load loading device comprises a main frame body, a sample mounting frame, a loading piece and a plurality of loading mechanisms; the sample mounting frame is connected with the main frame body and is used for mounting a sample; the plurality of loading mechanisms are connected with the main frame body, and the loading piece is in transmission connection with all the loading mechanisms; wherein the loading part is used for moving relative to the main frame body under the driving action of one or more loading mechanisms, so as to apply one or more loads of compression, rolling and sliding to the sample in the sample mounting frame. According to the simulated physiological load loading device, the simulated physiological load applying of compression, rolling and sliding coupling can be realized, so that obvious deviation between experimental data and an in-vivo actual mechanical environment can be avoided.

Description

Technical Field

[0001] This invention relates to the field of biomechanics, and more specifically, to a physiologically inspired load-bearing device and system. Background Technology

[0002] Knee cartilage is an avascular connective tissue covering the surface of the femoral condyle and tibial plateau. It plays a crucial role in transmitting joint loads and cushioning movement due to its unique biomechanical properties. Because cartilage has extremely weak self-repair capabilities, imbalances in the mechanical microenvironment (such as localized strain concentration and synergistic displacement disruption) are the core causes of cartilage degeneration (osteoarthritis) and mechanical injury. Clinical studies have shown that when the surface strain of cartilage exceeds 8%, collagen fiber breakage is likely to occur, while deep strain concentration may lead to cartilage matrix degradation.

[0003] However, existing technologies for monitoring knee cartilage mechanics lack biomimetic load application, leading to significant discrepancies between experimental data and the actual in vivo mechanical environment. Summary of the Invention

[0004] The present invention aims to provide a physiologically simulated load application device and system that can apply physiologically simulated loads through compression, rolling and sliding coupling, thereby avoiding significant deviations between experimental data and the actual mechanical environment in vivo.

[0005] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a physiological load-loading device, which includes a main frame, a sample mounting frame, a loading component, and multiple loading mechanisms. The sample mounting frame is connected to the main frame and is used to mount the sample; multiple loading mechanisms are connected to the main frame, and the loading components are driven by all the loading mechanisms. The loading element is used to move relative to the main frame under the driving action of one or more loading mechanisms, thereby applying one or more loads of compression, rolling and sliding to the specimen located in the specimen mounting frame.

[0006] In an optional implementation, the main frame includes a base plate, a connecting frame, and three support columns; The base plate is a triangular plate, with three support columns arranged in parallel and spaced apart. One end of each support column is connected to a corner of the base plate, and the other end of each of the three support columns is connected to the connecting frame. Multiple loading mechanisms are connected to the connecting frame.

[0007] In an optional embodiment, the connecting frame includes three first connecting columns, three first connecting members, and three connecting plates; The three first connecting posts are arranged in a triangle, with a first connecting piece at each corner and each first connecting piece connected to the two first connecting posts at that corner; the three connecting plates are each connected to a first connecting post, and the three connecting plates extend and connect towards the center of the triangle formed by the three first connecting posts. The physiological load-loading device includes three loading mechanisms, each of which is connected to a connecting plate. Each of the three first connectors is connected to a support column.

[0008] In an optional implementation, each loading mechanism includes a drive motor, a transmission component, a drive arm, and a connecting arm; The drive motor is connected to the corresponding connecting plate, the drive arm is rotatably connected to the main frame, and the two ends of the connecting arm are rotatably connected to the drive arm and the loading component, respectively. The rotation axis of the drive arm relative to the main frame, the rotation axis of the connecting arm relative to the drive arm, and the rotation axis of the connecting arm relative to the loading component are parallel, and are all parallel to the first connecting column corresponding to the connecting plate connected to the drive motor.

[0009] In an optional implementation, the main frame also includes three second connecting columns and three second connecting members; The three second connecting columns are arranged in a triangle, with a second connecting piece at each corner, and each second connecting piece is connected to the two second connecting columns at that corner; the three second connecting pieces are each connected to a support column. Among them, the three second connecting posts correspond one-to-one with the three first connecting posts and are parallel, and each driving arm is rotatably connected to a corresponding second connecting post. The rotation axis of each driving arm relative to its corresponding second connecting post is parallel to the second connecting post.

[0010] In an alternative embodiment, the transmission element includes a drive gear and an arcuate rack; The drive gear is connected to the main shaft of the drive motor; the arc-shaped rack is connected to the drive arm, and the arc-shaped rack is arranged around the axis of the second connecting column corresponding to the drive arm; The drive gear meshes with the arc-shaped rack.

[0011] In an optional implementation, the loading element includes a loading seat, a mounting fixture, and a loading wheel; The mounting fixture is connected to the loading seat, and the loading wheel is connected to the mounting fixture. The loading wheel is used to contact the sample. The connecting arms of all three loading mechanisms are connected to the loading seat.

[0012] In an optional implementation, the loading wheel is integrated into the pressure sensor.

[0013] In an optional embodiment, the sample mounting holder has a built-in load sensor.

[0014] Secondly, the present invention provides a physiological load loading system, which includes an image data acquisition unit and the aforementioned physiological load loading device. The image data acquisition unit is used to acquire motion image data of the loading component of the physiological load loading device and image data of the sample; The control unit is electrically connected to the image data acquisition unit, all loading mechanisms, pressure sensors, and load sensors.

[0015] The beneficial effects of the physiological-inspired load-applying device and system provided in this invention include: This biomimetic load application device includes a main frame, a sample mounting frame, a loading element, and multiple loading mechanisms. The sample mounting frame is connected to the main frame and is used to mount the sample. All loading mechanisms are connected to the main frame, and the loading element is drive-connected to all loading mechanisms. The loading element moves relative to the main frame under the drive of one or more loading mechanisms, thereby applying one or more loads of compression, rolling, and sliding to the sample located in the sample mounting frame. This biomimetic load application device can achieve biomimetic load application with compression, rolling, and sliding coupling, thus avoiding significant deviations between experimental data and the actual in vivo mechanical environment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the physiological load-bearing device provided in this embodiment from a first-view perspective. Figure 2 This is a schematic diagram of the physiological load-bearing device provided in this embodiment from a second perspective. Figure 3 This is a structural schematic diagram of the main frame provided in this embodiment; Figure 4 This is a schematic diagram of the loading mechanism's arrangement from a first-view perspective, provided in this embodiment. Figure 5 This is a schematic diagram of the arrangement of the loading mechanism from a second perspective provided in this embodiment; Figure 6 This is a schematic diagram of the loading mechanism provided in this embodiment; Figure 7This is a schematic diagram of the structure of the loading component provided in this embodiment.

[0018] Icons: 100-Physiological load-bearing device; 110-Main frame; 120-Sample mounting frame; 130-Loading component; 140-Loading mechanism; 111-Base plate; 112-Connecting frame; 113-Supporting column; 114-First connecting column; 115-First connecting component; 116-Connecting plate; 141-Drive motor; 142-Transmission component; 143-Drive arm; 144-Connecting arm; 117-Second connecting column; 118-Second connecting component; 145-Drive gear; 146-Arc rack; 131-Loading seat; 132-Mounting fixture; 133-Loading wheel. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, 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, and therefore should not be construed as a limitation of this invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] Knee cartilage is an avascular connective tissue covering the surface of the femoral condyle and tibial plateau. It plays a crucial role in transmitting joint loads and cushioning movement due to its unique biomechanical properties. Because cartilage has extremely weak self-repair capabilities, imbalances in the mechanical microenvironment (such as localized strain concentration and synergistic displacement disruption) are the core causes of cartilage degeneration (osteoarthritis) and mechanical injury. Clinical studies have shown that when the surface strain of cartilage exceeds 8%, collagen fiber breakage is likely to occur, while deep strain concentration may lead to cartilage matrix degradation.

[0026] The inventors discovered through research that the physiological loads on articular cartilage are complex (combining compressive loads, sliding loads, and rolling loads), dynamic (alternating loads of 0-3 times body weight during the gait cycle), and multi-degree-of-freedom (flexion-extension + rotation + shear coupling). However, existing technologies in knee cartilage biomechanical monitoring can only achieve static loading in a single direction, and cannot reproduce the load characteristics under real physiological conditions such as walking, running, and climbing stairs. This results in a lack of biomimetic load loading, leading to significant deviations between experimental data and the actual biomechanical environment in vivo.

[0027] Please refer to Figures 1-5 This embodiment provides a physiological load loading device 100, which includes a main frame 110, a sample mounting frame 120, a loading element 130, and multiple loading mechanisms 140. The sample mounting frame 120 is connected to the main frame 110 and is used to mount the sample; multiple loading mechanisms 140 are all connected to the main frame 110, and the loading element 130 is connected to all the loading mechanisms 140 in a transmission manner. The loading element 130 is used to move relative to the main frame 110 under the driving action of one or more loading mechanisms 140, thereby applying one or more loads of compression, rolling and sliding to the specimen located in the specimen mounting frame 120.

[0028] Please refer to Figures 1-5 The working principle of the physiological load-bearing device 100 is as follows: The biomimetic load application device 100 includes a main frame 110, a sample mounting frame 120, a loading element 130, and multiple loading mechanisms 140. The sample mounting frame 120 is connected to the main frame 110 and is used to mount the sample. All multiple loading mechanisms 140 are connected to the main frame 110, and the loading element 130 is drivenly connected to all loading mechanisms 140. The loading element 130 is used to move relative to the main frame 110 under the driving action of one or more loading mechanisms 140, thereby applying one or more loads of compression, rolling, and sliding to the sample located in the sample mounting frame 120.

[0029] Therefore, the physiological load loading device 100 adopts a method of transmission connection between multiple loading mechanisms 140 and loading element 130. In the process of use, the loading element 130 directly contacts the sample to complete the load loading. In this process, one or more loading mechanisms 140 can drive the loading element 130 to move. In this way, the application of physiological loads with compression, rolling and sliding coupling can be realized, thereby simulating the actual mechanical environment in the human body. Therefore, the biomimetic load application device 100 can achieve biomimetic load application with compression, rolling and sliding coupling, thereby avoiding significant deviations between experimental data and the actual mechanical environment in vivo.

[0030] It should be noted that in this embodiment, when configuring the physiological load application device 100, three loading mechanisms 140 are used. All three loading mechanisms 140 are connected to the loading member 130 through a transmission. Moreover, the three loading mechanisms 140 can operate synchronously or asynchronously. Their specific actions can be adjusted according to the actual load application requirements. Furthermore, when driving the loading member 130, the three loading mechanisms 140 drive it to move in different directions. In this way, the actions of the three loading mechanisms 140 can be controlled so that when the loading member 130 applies a load to the sample, the load can be in the form of compression, rolling, and sliding coupling.

[0031] Please refer to Figures 1-6 The specific structure of the main frame 110 and the three loading mechanisms 140 in this embodiment will be described in detail below.

[0032] Specifically, in this embodiment, when configuring the main frame 110, its function is to install the base plate 111, the sample mounting frame 120, and multiple loading mechanisms 140. That is, the main frame 110 can provide a stable loading environment. Therefore, the main frame 110 includes a base plate 111, a connecting frame 112, and three support columns 113. The base plate 111 is a triangular plate, and the three support columns 113 are arranged in parallel and at intervals. One end of each support column 113 is connected to a corner of the base plate 111, and the other end of each of the three support columns 113 is connected to the connecting frame 112. The multiple loading mechanisms 140 are all connected to the connecting frame 112.

[0033] Through the structural arrangement of the main frame 110, the three support columns 113 provide support, while the structural arrangement of the connecting frame 112 facilitates the installation of the three loading mechanisms 140. Moreover, when configuring the three support columns 113, they are arranged in a spaced and parallel manner. Based on this, an active space for the loading mechanism 140 to work can be formed between any two support columns 113. In this embodiment, three loading mechanisms 140 are configured accordingly. In this way, the three active spaces formed by the three support columns 113 can each correspond to one loading mechanism 140. This method can ensure the installation stability of the loading mechanism 140 and facilitate the operation of the three loading mechanisms 140.

[0034] When configuring the connecting frame 112, its structural function is to facilitate the installation of the three loading mechanisms 140. Specifically, the connecting frame 112 includes three first connecting columns 114, three first connecting pieces 115, and three connecting plates 116. The three first connecting posts 114 are arranged in a triangle, with a first connecting piece 115 corresponding to each corner. Each first connecting piece 115 is connected to the two first connecting posts 114 at that corner. The three connecting plates 116 are each connected to one of the first connecting posts 114. The three connecting plates 116 extend and connect towards the center of the triangle formed by the three first connecting posts 114. The physiological load loading device 100 includes three loading mechanisms 140, each of which is connected to one of the connecting plates 116. Among them, the three first connectors 115 are respectively connected to a support column 113.

[0035] Therefore, through the above structural arrangement, it should be noted that the three first connecting columns 114 can be connected with the first connecting member 115 to form a triangle that is the same as or similar to the base plate 111, and the three first connecting columns 114 can be connected with the three supporting columns 113. Moreover, the three first connecting columns 114 correspond to one side of the triangle formed. On this basis, the three connecting plates 116, when each is connected to a first connecting column 114, extend towards the center of the triangle, and their extended ends are connected together. Thus, the three connecting plates 116 can be connected together to form a Y-shaped plate structure, thereby improving the structural strength of the overall structure and improving the working stability of the loading mechanism 140.

[0036] When configuring the loading mechanism 140, based on the above information, please refer to... Figures 1-6Each of the three loading mechanisms 140 is connected to a connecting plate 116. When the three support columns 113 of the main frame 110 form three active spaces, each of the three loading mechanisms 140 corresponds to one active space. Moreover, the three loading mechanisms 140 have the same structure. Therefore, the following explanation will take one of the loading mechanisms 140 as an example. Each loading mechanism 140 includes a drive motor 141, a transmission component 142, a drive arm 143, and a connecting arm 144; The drive motor 141 is connected to the corresponding connecting plate 116, the drive arm 143 is rotatably connected to the main frame 110, and the two ends of the connecting arm 144 are rotatably connected to the drive arm 143 and the loading member 130, respectively. The rotation axis of the drive arm 143 relative to the main frame 110, the rotation axis of the connecting arm 144 relative to the drive arm 143, and the rotation axis of the connecting arm 144 relative to the loading member 130 are parallel, and are all parallel to the first connecting post 114 corresponding to the connecting plate 116 connected to the drive motor 141.

[0037] With the above-described structure, the drive motor 141 can drive the drive arm 143 to rotate relative to the main frame 110. The rotation of the drive arm 143 can then drive the connecting arm 144 and the loading member 130 connected to the connecting arm 144 to move. Furthermore, since three loading mechanisms 140 are configured, the independent control of the three loading mechanisms 140 can make their movements synchronous or asynchronous. This allows the three loading mechanisms 140 to drive the loading member 130 to apply a load to the sample. The form of the load can be achieved by controlling the three drive motors 141 to apply physiologically simulated loads such as compression, rolling, and sliding coupling.

[0038] It should be noted that, taking the application of compressive load as an example, the three drive motors 141 can be controlled to move synchronously, thereby making the movements of the three drive arms 143 synchronous and consistent, so that the loading member 130 applies load in a direction perpendicular to the sample, thereby achieving the application of compressive load; while rolling and sliding loads can be achieved by controlling one or more of the drive motors 141, which will not be elaborated here.

[0039] Based on the above structure, during the application of load, the loading mechanism 140 drives the drive arm 143 to move through the action of the drive motor 141. In order to improve the stability of the drive arm 143, the main frame 110 also includes three second connecting columns 117 and three second connecting pieces 118. The three second connecting posts 117 are arranged in a triangle, with a second connecting piece 118 corresponding to each corner. Each second connecting piece 118 is connected to the two second connecting posts 117 at that corner. The three second connecting pieces 118 are each connected to a support post 113. Among them, the three second connecting posts 117 correspond one-to-one with the three first connecting posts 114 and are parallel, and each driving arm 143 is rotatably connected to one of the second connecting posts 117. The rotation axis of each driving arm 143 relative to its corresponding second connecting post 117 is parallel to the second connecting post 117.

[0040] As can be seen from the above, the three second connecting columns 117 are arranged in a triangle. In addition to being interconnected by multiple second connecting pieces 118, they can also be connected to the three support columns 113 through the second connecting pieces 118. Therefore, the structural setting principle of the three second connecting columns 117 is the same as that of the three first connecting columns 114. Moreover, on this basis, the three second connecting columns 117 correspond to a loading mechanism 140 and also correspond to an active space. In this way, the rotational stability of the three drive arms 143 can be improved through the structural setting of the three second connecting columns 117.

[0041] Based on the above structure, there are various driving methods when connecting the drive motor 141 and the drive arm 143. In this embodiment, to improve the control accuracy of its rotation, the transmission component 142 includes a drive gear 145 and an arc-shaped rack 146. The drive gear 145 is connected to the main shaft of the drive motor 141; the arc-shaped rack 146 is connected to the drive arm 143, and the arc-shaped rack 146 is arranged around the axis of the second connecting post 117 corresponding to the drive arm 143; the drive gear 145 meshes with the arc-shaped rack 146. Thus, with this arrangement, the drive arm 143 can be driven to rotate by the drive motor 141, and the control of its rotation can be adjusted based on the number of meshing teeth.

[0042] Please refer to Figures 1-7 When the loading member 130 is configured, its function is to contact the sample and apply a load to the sample. In order to reduce the friction at the contact point between the loading member 130 and the sample, a wheel-type structure can be used for contact. In other embodiments of the present invention, other structural forms can also be used.

[0043] For details, please refer to Figures 1-7In this embodiment, the loading member 130 includes a loading seat 131, a mounting fixture 132, and a loading wheel 133; the mounting fixture 132 is connected to the loading seat 131, the loading wheel 133 is connected to the mounting fixture 132, and the loading wheel 133 is used to contact the sample; wherein, the connecting arms 144 of the three loading mechanisms 140 are all connected to the loading seat 131.

[0044] Thus, by means of this, the loading seat 131 can be connected to the three loading mechanisms 140, and by means of the operation of one or more of the three loading mechanisms 140, the loading can be driven to move relative to the main frame 110. In this way, when the loading wheel 133 contacts the sample, the loading form can be adjusted by means of the operation of one or more of the three loading mechanisms 140, so that the loading form is one or more of compression, rolling and sliding.

[0045] Traditional loading devices can only collect macroscopic load and contact pressure data, failing to capture the microscopic mechanical response of cartilage (such as strain differences between the surface and deep layers of cartilage, and changes in local strain gradients), making it difficult to establish a quantitative correlation mechanism between "macroscopic load and microscopic damage." Furthermore, most devices do not achieve synchronous triggering of loading and monitoring, leading to misaligned data timestamps and distorted correspondence between mechanical parameters and damage evolution. Therefore, to detect parameters during the loading process, a pressure sensor is built into the loading wheel 133, and a load sensor is built into the sample mounting frame 120. The pressure sensor captures the pressure distribution characteristics at the interface between the sample and the loading wheel 133; while the load sensor allows for real-time acquisition of macroscopic load data applied to the sample.

[0046] Based on the above, please refer to Figures 1-7 This embodiment also provides a physiological load loading system, which includes an image data acquisition unit and the above-mentioned physiological load loading device 100. The image data acquisition unit is used to acquire motion image data of the loading component 130 of the physiological load loading device 100 and image data of the sample; The control unit is electrically connected to the image data acquisition unit, all loading mechanisms 140, pressure sensors, and load sensors.

[0047] It should be noted that the physiological load loading system, by adopting the aforementioned physiological load loading device 100, possesses all the advantages of the physiological load loading device 100. Moreover, while acquiring motion image data of the loading component 130 of the physiological load loading device 100 and image data of the sample, the system can also receive the output image data through the control unit, as well as the pressure data of the contact interface between the sample and the loading wheel 133, and the load data applied to the sample. It can also control all loading mechanisms 140.

[0048] In summary, the physiological load loading system provided in this embodiment, by employing the aforementioned physiological load loading device 100, can accurately monitor the dynamic evolution of the micromechanical parameters (layered displacement, global strain, strain gradient) of knee joint cartilage tissue (ex vivo natural cartilage, engineered cartilage) under physiological load, providing core data support for cartilage damage mechanism research, cartilage repair material optimization, and knee joint cartilage prosthesis fit assessment.

[0049] Please refer to Figures 1-7 The structure of this physiologically simulated load-bearing system will be described in detail below: First, the three support columns 113 of the main frame 110 are all made of high-strength aluminum alloy (e.g., model parameters could be 6061-T6, diameter 25mm, length 500mm); the Y-shaped support plate formed by the three connecting plates 116 can be 15mm thick and made of aluminum; and the triangular base plate 111 can be 20mm thick and made of No. 45 steel to improve the stability during loading; and the aforementioned structural configuration can form a stable triangular support structure. Furthermore, the support column 113, the base plate 111, and the connecting plate 116 are all connected by threads with locking nuts (such as M12 threads), and the height is adjustable (adjustment range 300-500mm) to accommodate samples of different sizes. A shock-absorbing pad (Shore hardness 60° silicone material) is provided at the bottom of the base plate 111 to reduce vibration interference during the load application process.

[0050] When configuring the drive motors 141, all three drive motors 141 can use a 42BYG250C stepper motor (with parameters of holding torque 0.44 N·m, step angle 1.8°, and drive voltage 48VDC) as the power source. Each drive motor 141 can be connected to the corresponding drive gear 145 through a coupling. The drive gear 145 has a module of 1, 14 teeth, a tooth width of 11 mm, and is made of 30CrMnSi. The arc-shaped rack 146 meshing with the drive gear 145 has a module of 1, 123 teeth, and a tooth width of 11 mm. Thus, the transmission ratio between the drive gear 145 and the arc-shaped rack 146 is 123:14. It should be noted that all three drive motors 141 are driven by a closed-loop control system with a position positioning accuracy of ±0.01 mm and a load application frequency range of 0.5-5 Hz, which is suitable for different working conditions such as simulated walking (1 Hz) and running (3-5 Hz).

[0051] The loading wheel 133 is connected via the mounting clamp 132 to apply compression, rolling, and sliding coupled loads under the drive of the loading mechanism 140. This configuration allows for replaceable roller components, which can be connected to the loading seat 131 via double-ended bolts during installation, enabling quick replacement to adjust the contact method. Furthermore, the mounting clamp 132 is connected to the loading seat 131 via a ball joint, allowing for adaptive adjustment of the loading wheel 133's posture. The loading seat 131 incorporates an SKF W619 / 3-2Z rolling bearing (rated dynamic load 390N) for rotatable connection with the loading wheel 133, reducing roller rotation friction. When configuring the sample mounting rack 120, in order to facilitate the installation of the sample, the sample mounting rack 120 is equipped with a sample fixing clamp, and the sample mounting rack 120 is provided with an adjustable V-groove structure with a clamping range of 10-50mm. The contact surface between the sample fixing clamp and the sample is provided with an inner silicone pad (3mm thick) to avoid damaging the sample. The sample fixing clamp is locked with M10 bolts, and the clamping force is adjustable from 0-50N to ensure good contact with the sample surface. When configuring the pressure sensor and load sensor, a miniature pressure sensor (range 0-1MPa, accuracy ±1%FS) is embedded inside the loading wheel 133 to capture the pressure distribution characteristics of the contact interface. The data sampling frequency is 1000Hz to ensure data synchronization with the DIC system. Meanwhile, a PLD204L-15 type load sensor (range 0.5-50Kg, nonlinearity ±0.05%FS) is embedded at the bottom of the sample fixing fixture to collect macroscopic load data applied to the sample in real time.

[0052] In this physiologically simulated load-bearing system, the image data acquisition unit and the control unit together form a DIC system; Specifically, the DIC system consists of a high-speed camera, an LED surface light source, an image acquisition card, and analysis software, with an optimized imaging scheme specifically designed for cartilage tissue. The high-speed camera, LED surface light source, and image acquisition card constitute the image data acquisition unit. The high-speed camera can be a CMOS camera with a resolution of 1920×1080 pixels, an adjustable frame rate range of 10-100fps, a lens focal length of 50mm, and a working distance of 100-200mm to ensure clear imaging of the sample side. The camera is fixed on an adjustable tripod (height adjustment range of 500-1500mm, horizontal rotation of 360°), arranged parallel to the side of the main frame 110, with the center of the lens at the same height as the center of the sample. The LED surface light source uses a cold light source (color temperature 5500K, power 50W) with light uniformity ≥90%. The light is projected onto the sample surface through a diffuser plate to avoid strong light reflection interfering with imaging. The light source angle is adjustable (±45°) to ensure that the speckle contrast meets the measurement requirements. Image acquisition card: The transmission interface is USB3.0, the data transmission rate is ≥5Gbps, and it supports real-time image storage and preprocessing to ensure no frame loss. The analysis software is applied in the control unit. It is developed based on digital image correlation algorithms and integrates a layered strain extraction module, a strain gradient calculation module, and a dynamic evolution visualization module. It supports custom regions of interest (ROI) and can accurately extract displacement and strain data of the cartilage surface (0-500μm), middle layer (500-1000μm), and deep layer (1000-1500μm), with a measurement accuracy of ±0.01% and a strain resolution of 0.001%.

[0053] For the specific structure of the above-described physiological-inspired load-loading system, please refer to [reference needed]. Figures 1-7 The working process of this physiologically simulated load-bearing system will be described in detail below: 1. System preprocessing and checks: Sample preparation: Select isolated natural cartilage or engineered cartilage samples and cut them into cuboids with dimensions of 20mm × 10mm × 5mm (length × width × thickness). Random speckle patterns (speckle diameter 50-100μm, made of biocompatible fluorescent pigment to avoid reaction with cartilage tissue) are prepared on the side of the sample by air spraying. The sample is then immersed in phosphate-buffered saline (PBS) for 30 min to simulate the in vivo physiological environment. System check: Check the mechanical connections of the physiological load loading device 100, whether the support column 113, each connecting rod, the mounting clamp 132 and the loading mechanism 140 are secure, the interface connection between the drive motor 141 and the control unit is intact, and the load sensor is calibrated with standard weights (calibration error ≤0.1%); turn on the DIC system and check that the camera and surface light source are working properly and the image acquisition card is transmitting stably; test the coordination of each module through the synchronization controller to ensure that the trigger delay is ≤1ms.

[0054] Sample clamping and system debugging: Install loading wheel 133. Select the loading wheel 133 with the corresponding diameter according to the experimental requirements. Fix it to loading seat 131 with double-headed bolts. Tighten the torque to 5 N·m to ensure that loading wheel 133 rotates flexibly without jamming. Sample clamping: Place the pretreated sample in the V-groove of the sample holder, adjust the sample position so that the test surface faces the camera, and slowly clamp the sample with bolts. The clamping force should be controlled at 10-20N to avoid sample deformation or damage. DIC system debugging: Adjust the tripod height and camera angle to fill the imaging field of view (field of view range 25mm×15mm) with the side of the sample, turn on the LED surface light source, and adjust the light angle and brightness to ensure speckle contrast ≥30%; perform image pre-acquisition through analysis software, check that there is no speckle detachment or reflection, and set the region of interest (surface, middle, deep) and measurement parameters (sampling interval, strain calculation window).

[0055] 2. Physiological-inspired load loading and data acquisition: Parameter settings: The physiological load parameters of each loading mechanism during operation are set through the control unit, including load type (compression + rolling + sliding coupling load), load magnitude (0-3 times body weight, corresponding to 0-1800N, converted to contact pressure 0-3MPa according to sample size), loading frequency (0.5-5Hz), and number of loading cycles (1-10000 times); the data acquisition parameters are set through the synchronous controller, including DIC imaging interval (1-10s / frame, adjusted according to the loading frequency to ensure ≥5 frames of images are acquired per loading cycle) and load data sampling frequency (1000Hz). Loading and Acquisition: The synchronous control module is activated, and each loading mechanism 140 applies physiological loads according to the set parameters. At the same time, the DIC system performs imaging scans synchronously, and the load monitoring module collects macroscopic load and contact pressure data in real time. All data is stored on the server and automatically associated with timestamps.

[0056] 3. Data Processing and Analysis: Image processing: The acquired image sequences are registered and correlated using DIC analysis software to extract global displacement and strain field data, with a focus on analyzing the layered strain values ​​and strain gradient changes in the surface, middle, and deep layers. Data correlation: Align load data and strain data by timestamp to establish a "macro load - micro strain" correlation curve and identify the correspondence between strain concentration areas and load thresholds; Visualization output: The software generates dynamic evolution maps of the mechanical microenvironment, including layered strain time-series curves, global strain cloud maps, and strain gradient distribution maps, and supports data export (in Excel and TIF formats).

[0057] Based on the above-mentioned physiological-inspired loading system, the following example illustrates its application to the monitoring of the mechanical microenvironment of isolated natural cartilage under walking conditions: Sample preparation: Select healthy adult pig knee joint cartilage, cut it into 20mm×10mm×5mm samples, prepare fluorescent speckles (50μm in diameter) on the side, and soak in PBS for 30min; System settings: The physiological load loading device 100 is set to walking conditions parameters, with a load size of 1 times body weight (corresponding to a contact pressure of 1 MPa), a loading frequency of 1 Hz, and a loading cycle of 1000 times; the DIC imaging interval is 1 s / frame, and the load sampling frequency is 1000 Hz. Experimental procedure: The clamping, debugging, loading and data acquisition were completed according to the above monitoring method and steps, and the evolution of the mechanical microenvironment was continuously monitored within 1000 cycles; Results: Layered strain values ​​of the superficial, middle, and deep cartilage layers were successfully captured. The maximum strain was 6.8% in the superficial layer, 4.2% in the middle layer, and 2.5% in the deep layer, with the strain gradient decreasing along the thickness direction. After 500 cycles, a sudden increase in strain (from 6.8% to 8.2%) was observed in the strain concentration area of ​​the superficial layer, while the corresponding macroscopic load did not change significantly, indicating that collagen fibers began to break, providing data support for early warning of cartilage damage.

[0058] Based on the above-mentioned physiologically inspired load-loading system, the following explanation will take the application of the physiologically inspired load-loading system in the mechanical compatibility evaluation of engineered cartilage repair materials as an example: Sample preparation: Engineered cartilage samples constructed from polylactic acid-glycolic acid copolymer (PLGA) scaffolds and chondrocytes were selected, with dimensions of 20 mm × 10 mm × 5 mm, and speckled patterns were prepared on the side. System settings: The physiological load loading device 100 is set to a load size of 0.5 times the body weight (contact pressure 0.5 MPa), a loading frequency of 0.5 Hz, and a loading cycle count of 5000 times; the DIC imaging interval is 5 seconds per frame. Experimental procedure: The experiment was conducted according to the monitoring method to compare the differences in mechanical response between engineered cartilage and natural cartilage; Results: The maximum strain of engineered cartilage was 8.5% in the surface layer, 5.1% in the middle layer, and 3.0% in the deep layer. The strain concentration area was more dispersed than that of natural cartilage. After 5000 cycles, the strain value did not drift significantly, indicating that the repair material has good mechanical stability and is suitable for the physiological and mechanical environment, providing a quantitative basis for material optimization.

[0059] Based on the above, please refer to Figures 1-7 The biomimetic load loading device 100, and the biomimetic load loading system employing the biomimetic load loading device 100, have at least the following advantages: It can achieve deep coupling between physiological load and microscopic monitoring: the loading device realizes the application of composite loads with compression, rolling and sliding coupling. The load parameters (magnitude, frequency and mode) can be accurately matched with physiological conditions such as walking and running. At the same time, combined with the optimized DIC system, it realizes dynamic quantitative monitoring of cartilage tissue layered strain and global strain gradient for the first time, establishes a direct correlation between "macroscopic load and microscopic mechanical response", and solves the problem of disconnect between loading and monitoring in traditional technology.

[0060] The monitoring accuracy and reliability are significantly improved: the DIC imaging scheme (fluorescence speckle, cold light source, and layered ROI settings) is optimized for cartilage tissue characteristics, and the strain measurement accuracy reaches ±0.01% and the strain resolution is 0.001%, which can effectively capture the strain difference between the surface and deep layers (minimum identification difference of 0.1%); the synchronization control module ensures data timestamp synchronization (delay ≤1ms) to avoid analysis errors caused by data misalignment.

[0061] Integration and ease of operation: It integrates sample clamping, load application, image acquisition, and data processing into one unit, eliminating the need for additional multi-device connection systems; the replaceable roller assembly and adjustable clamps are compatible with cartilage samples of different sizes and types (ex vivo natural cartilage, engineered cartilage, and repair material samples); the analysis software has a built-in automated processing module that supports real-time visualization of dynamic evolution spectra, reducing the operational threshold.

[0062] Its applications are wide-ranging: it can provide core data support for the study of cartilage injury mechanisms (such as the correlation between strain concentration and collagen breakage), optimization of cartilage repair materials (such as the mechanical compatibility assessment of different scaffold materials), and knee joint prosthesis design (such as the influence of prosthesis surface morphology on the cartilage mechanical environment), thus promoting technological progress in the fields of biomechanics and cartilage tissue engineering.

[0063] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A physiologically simulated load-bearing device, characterized in that: The biomimetic load loading device includes a main frame, a sample mounting frame, a loading component, and multiple loading mechanisms. The sample mounting frame is connected to the main frame and is used to mount the sample; multiple loading mechanisms are all connected to the main frame, and the loading component is drivenly connected to all the loading mechanisms; The loading member is used to move relative to the main frame under the driving action of one or more of the loading mechanisms, thereby applying one or more loads of compression, rolling and sliding to the specimen located in the specimen mounting frame.

2. The physiological-inspired load-loading device according to claim 1, characterized in that: The main frame includes a base plate, a connecting frame, and three support columns; The base plate is a triangular plate, and the three support columns are arranged in parallel and spaced apart. One end of each support column is connected to a corner of the base plate, and the other end of each of the three support columns is connected to the connecting frame. All of the loading mechanisms are connected to the connecting frame.

3. The physiological-inspired load-loading device according to claim 2, characterized in that: The connecting frame includes three first connecting columns, three first connecting pieces, and three connecting plates; The three first connecting posts are arranged in a triangle, with one first connecting piece at each corner and each first connecting piece connected to the two first connecting posts at that corner; the three connecting plates are each connected to one of the first connecting posts, and the three connecting plates extend and connect toward the center of the triangle formed by the three first connecting posts. The biomimetic load loading device includes three loading mechanisms, each of which is connected to one of the connecting plates. Each of the three first connectors is connected to one of the support columns.

4. The physiological-inspired load-loading device according to claim 3, characterized in that: Each of the loading mechanisms includes a drive motor, a transmission component, a drive arm, and a connecting arm; The drive motor is connected to the corresponding connecting plate, the drive arm is rotatably connected to the main frame, and both ends of the connecting arm are rotatably connected to the drive arm and the loading member, respectively. The rotation axis of the drive arm relative to the main frame, the rotation axis of the connecting arm relative to the drive arm, and the rotation axis of the connecting arm relative to the loading member are all parallel, and are all parallel to the first connecting column corresponding to the connecting plate connected to the drive motor.

5. The physiological-inspired load-loading device according to claim 4, characterized in that: The main frame also includes three second connecting columns and three second connecting pieces; The three second connecting columns are arranged in a triangle, with one second connecting piece at each corner, and each second connecting piece is connected to the two second connecting columns at that corner; the three second connecting pieces are each connected to one of the supporting columns. The three second connecting posts correspond one-to-one with the three first connecting posts and are parallel to each other. Each driving arm is rotatably connected to one of the second connecting posts, and the rotation axis of each driving arm relative to its corresponding second connecting post is parallel to the second connecting post.

6. The physiologically simulated load-bearing device according to claim 5, characterized in that: The transmission component includes a drive gear and an arc-shaped rack; The drive gear is connected to the main shaft of the drive motor; the arc-shaped rack is connected to the drive arm, and the arc-shaped rack is arranged around the axis of the second connecting column corresponding to the drive arm; The drive gear meshes with the arc-shaped rack.

7. The physiologically simulated load-bearing device according to claim 4, characterized in that: The loading component includes a loading seat, a mounting fixture, and a loading wheel; The mounting fixture is connected to the loading seat, the loading wheel is connected to the mounting fixture, and the loading wheel is used to contact the sample; The connecting arms of all three loading mechanisms are connected to the loading seat.

8. The physiological-inspired load-loading device according to claim 7, characterized in that: The loading wheel is built into the pressure sensor.

9. The physiological-inspired load-bearing device according to any one of claims 1-8, characterized in that: The sample mounting frame has a built-in load sensor.

10. A physiologically inspired load-bearing system, characterized in that: The biomimetic load loading system includes an image data acquisition unit, a control unit, and a biomimetic load loading device as described in any one of claims 1-9; The image data acquisition unit is used to acquire motion image data of the loading component of the biomimetic load loading device and image data of the sample. The control unit is electrically connected to the image data acquisition unit, all loading mechanisms, pressure sensors, and load sensors.

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