Bionic model of bicycle rider injury with fiftieth percentile male signs and construction method and application thereof

Abstract

The application discloses a bionic model of a bicycle rider injury, also referred to as a biomechanical model, with the Chinese 50th percentile male body sign, which is a digital calculation tool in the technical field of vehicle safety and intelligent high-end detection equipment. The bionic model of the injury conforms to the Chinese 50th percentile male body sign parameter of the latest human body size statistical data of the China Standardization Research Institute; the model has detailed human anatomy structure features and conforms to the standard riding posture in the international standard ISO 19206-4:2020. The content of the application can provide a theoretical basis for optimizing a bicycle rider safety protection system and has a wide application prospect in improving the safety protection level of vulnerable road users in China.

Description

Technical Field

[0001] This invention relates to the fields of vehicle transport safety and biomechanics of human injury, and in particular to a biomimetic model of cyclist injury with physical characteristics of a male at the 50th percentile in China and its construction method, as well as its application in the study of human collision injury mechanisms in the field of vehicle collision safety. Background Technology

[0002] Cyclists are often considered among the most vulnerable road users. In traffic accidents, they lack sufficient protection compared to motor vehicles and are often economically disadvantaged, making them more susceptible to serious injury. With rapid urbanization and the rise of green transportation trends, more and more people are choosing bicycles as their daily mode of transport. While this improves traffic efficiency and reduces environmental pollution, it also increases the safety risks faced by cyclists. Therefore, research on injury protection for cyclists is of great significance.

[0003] Currently, various finite element models of the human body exist internationally, but research on finite element models for cyclists is relatively scarce, especially lacking finite element models of cyclists with detailed anatomical structures adjusted according to standard definitions. Developing a biomimetic injury model for cyclists that conforms to the physical characteristics of the 50th percentile male in China, and analyzing the injury mechanism and response, can provide a theoretical basis for optimizing cyclist safety protection systems, and is of great significance for improving the safety protection level of vulnerable road users in my country.

[0004] Existing research often employs methods such as registering and adjusting a general human finite element model with a bicycle geometric model, or directly reconstructing riding postures from traffic accident video images. These methods not only lack standardized definitions based on standard cycling biomechanical postures, but also suffer from shortcomings in complex joint modeling, making it difficult to accurately reproduce the coordinated postures of the lower limbs, trunk, and upper limbs during real-world cycling. Furthermore, the basic human models used are generally constructed based on the physical characteristics of the 50th percentile males in Europe and America, whose body proportions, limb length, and mass distribution differ significantly from those of the Chinese population. This leads to distorted biomechanical responses in Chinese cycling scenarios, making it difficult to support injury mechanism analysis and safety protection design for vulnerable road users in China. Summary of the Invention

[0005] To address the shortcomings of the aforementioned technologies, the present invention aims to provide a biomimetic model of cyclist injury based on the standard cycling posture in the international standard ISO 19206-4-2020, which features physical characteristics of a Chinese male at the 50th percentile, as well as its construction method and application scenarios.

[0006] This invention proposes a method for constructing a biomimetic model of injuries in Chinese male cyclists with detailed anatomical structures at the 50th percentile. The method uses a standing injury biomimetic model with physical characteristics of Chinese males at the 50th percentile as a baseline model and includes the following steps:

[0007] Step A: Determine the rotation centers of important joints on the baseline model;

[0008] Step B: Adjust the lower limb finite element model of the baseline model according to the standard riding posture;

[0009] Step C: Adjust the torso lean angle of the baseline model according to the angle in the standard riding posture;

[0010] Step D: Adjust the upper limb finite element model of the baseline model according to the standard riding posture;

[0011] Step E: Integrate and adjust the whole-body soft tissue continuity of the model;

[0012] Step F: Check and adjust the penetration problem to obtain a biomimetic model of cyclist injury with physical characteristics of the 50th percentile male in China.

[0013] Preferably, the standing injury biomimetic model with the physical characteristics of a Chinese 50th percentile male is the TUST IBMs M50-P male car occupant injury biomimetic model.

[0014] Preferably, the standard riding posture is the standard riding posture specified in the international standard ISO 19206-4:2020.

[0015] In this invention, step A involves determining the rotation centers of important joints on a reference model to ensure the rationality of bone movement direction and soft tissue deformation. Specific steps include:

[0016] Step A1: Select the nodes of the left and right femoral head rotation centers of the reference model, and take the midpoint of the line connecting the two points as the hip joint rotation center;

[0017] Step A2: Select the patella, femoral condyle, and tibial condyle on both sides of the reference model respectively, and use the ND_R_BD command under the LS-DYNA panel to find the midpoint of each of the three on the left and right sides, which will be used as the rotation center of the left and right knee joints;

[0018] Step A3: Select the proximal and distal ends of the tibia of the reference model, select the center of each, construct the line connecting the two points and the extension line using the Curves command under the TOPO module, and extend the line downwards, taking the lowest intersection point with the outer surface of the shoe as the lower edge point of the left and right feet.

[0019] In this invention, step B involves adjusting the lower limb finite element model of the baseline model according to the standard cycling posture. Key angle parameters of the lower limbs are determined based on the ISO standard cycling posture diagram. The angle between the thigh and the horizontal plane is obtained according to the standard diagram. Rotational adjustment is applied to the femur through the hip joint rotation center to bring the thigh to a specified angle and maintain its natural anatomical position in the sagittal and coronal planes. The lower leg position is adjusted according to the knee joint rotation center to ensure that the knee flexion and extension direction conforms to the real human body. The foot posture is determined by the contact constraint between the foot's edge and the pedal, maintaining contact between the sole plane and the pedal and preserving the true geometric continuity between the tibia and the foot. Specific steps include:

[0020] Step B1: Import the standard cycling posture diagram into CATIA software. Use the spline curve command to construct lines, connecting the left and right knee joints to the hip joint rotation center to generate two straight lines I and II. Then connect the knee joint rotation center to the foot edge to generate two straight lines III and IV. Establish an X-axis horizontal line passing through the hip joint rotation center. Use the "Measure" tool to measure the angles between lines I and II and the horizontal plane, as well as the angles between line III and line I, and between line IV and line II. These measurements will serve as the basis for initial model adjustments.

[0021] Step B2: Based on the angle data measured in the standard diagram, initially adjust the angle between the left and right thighs and the horizontal plane, and then fine-tune the thigh position by registering the knee joint rotation center; adjust the angle between the left and right lower legs and the thighs, and then adjust the lower leg position by registering the foot edge point;

[0022] Step B3: Further adjust the position according to the coordinates given in the standard to make the lower limb posture meet the spatial geometric relationship corresponding to the riding posture.

[0023] In this invention, in step C, the torso of the reference model is adjusted in the sagittal plane, tilting it 10° or 30° forward towards the front of the body with the center of rotation of the hip joint as the center of rotation. At the same time, the line connecting the center of mass of the first thoracic vertebra to the center of rotation of the hip joint is used as a reference axis to constrain the angular relationship between it and the vertical direction, thus completing the adjustment of the torso angle for the two riding postures.

[0024] In this invention, step D introduces a "three-segment geometric reference line" to achieve precise positioning of the upper limb posture in spatial relationships, and adjusts the posture according to the geometric reference line to achieve the spatial positional relationship between the shoulder joint, elbow joint, wrist joint, and distal end of the hand that conforms to the standard cycling posture. Specific steps include:

[0025] Step D1: Obtain posture image information of the cyclist's upper limbs under actual cycling conditions. The posture image information includes the relative positional relationship and joint spatial distribution characteristics of the cyclist's upper limbs during cycling. The posture image information can be obtained by taking pictures with an image acquisition device, extracting video sequences, calling existing posture databases, or obtaining publicly available human posture data.

[0026] Step D2: Based on the posture image information, the key joint positions of the cyclist's upper limbs are calibrated, and the positional and angular relationships between the joints of the upper limbs are extracted;

[0027] Step D3: Import the joint position and angle relationship as posture constraints into the 3D modeling software to construct a geometric model of the rider's upper limbs that is consistent with the actual riding posture.

[0028] Step D4: Import the three geometric curves into ANSA software and scale the geometric curves to make them consistent with the length of the model.

[0029] Step D5: After moving the three geometric curves to the center of shoulder joint rotation, align them with the bicycle handlebars so that the hand geometric curves are placed on the handlebars;

[0030] Step D6: Select the upper limb finite element model in ANSA software and register it with the extracted geometric curves using the Mirror 3 point Plane command.

[0031] In this invention, step E involves adjusting the continuity of the model's whole-body soft tissue. Specific steps include:

[0032] Step E1: Upper and lower limb muscle adjustment. For muscles on the flexed side, morphological reconstruction is performed, compressing the distal muscle ends connected to the bone while increasing density. For muscles involving interference and penetration, the outermost hexahedral mesh is removed, and the removed portion is reconstructed using a pentahedral mesh, ensuring the appearance conforms to biomechanical properties. For muscles on the extended side, the mesh at the muscle ends connected to the bone is stretched and the mesh count is increased to maintain biomechanical properties. Tendons at joints are reconstructed using Shell units, and ligaments are reconstructed using a hybrid Shell and Solid approach.

[0033] Step E2: Construct the adipose tissue lining. Fat cells are generated at the knee, hip, elbow, and shoulder joints. Shell cells are then generated on these fat cells to reconstruct the skin. Connections between any two layers are made using a shared-node approach, with shared nodes and spatial geometry constraining the relative displacement between soft tissue and bone. After reconstruction, a mesh penetration check is performed on the reconstructed portion. The Intersections command in ANSA software is used to calculate and check the penetration between bone and muscle, between bone / muscle and ligament / tendon, and between muscle and fat.

[0034] In this invention, step F involves performing a full-body penetration check and adjustment on the model. The adjusted lower limbs, torso, and upper limbs are integrated, and the entire model is checked for penetration issues. For meshes with penetration problems, the move or fix command should be used for local adjustments to eliminate penetration phenomena, ensuring no geometric interference between the model's components, ultimately resulting in a biomimetic model of a cyclist's injury with physical characteristics of a Chinese 50th percentile male.

[0035] This invention also proposes a biomimetic model of cyclist injury based on the above method, constructed with physical characteristics of a Chinese male at the 50th percentile. The model strictly adheres to the standard cycling posture requirements specified in the international standard ISO 19206-4:2020 in terms of geometry, joint spatial positions, and limb posture angles. Specifically, this includes: the angle between the line connecting the center of mass of the first thoracic vertebra and the center of rotation of the hip joint and the vertical direction is 10° or 30° for two typical cycling conditions; the spatial positions of the thigh and lower leg are adjusted according to the coordinates specified in the international standard to ensure that the posture meets the standard requirements; the contact position between the lower edge of the foot and the ground conforms to the standard shoe-pedal contact geometry; and the upper limb posture is calibrated based on real cycling data to ensure that the spatial distribution of the shoulder, elbow, and wrist joints is consistent with the actual cycling state. Furthermore, the model possesses complete anatomical details, including multiple tissue layers such as bones, muscles, ligaments, tendons, fat, and skin. These tissues are connected by common nodes and maintain biomechanical continuity, making it suitable for high-precision collision simulation analysis.

[0036] The biomimetic damage model proposed in this invention can be applied to the simulation of typical vehicle collision scenarios. In the simulation, the cyclist model is placed directly in front of the moving vehicle and configured according to the actual collision test conditions, including: vehicle speed, gravity field simulation of the real environment, contact between the cyclist and the bicycle, car, and ground, self-contact of the cyclist, contact between the vehicle and the ground, and setting the friction force between the vehicle and the ground. The simulation can effectively evaluate various injury types such as fractures, traumatic brain injury, and internal organ damage.

[0037] The biomimetic model of cyclist injury disclosed in this invention, which reflects the physical characteristics of the 50th percentile male in China, has the following beneficial effects: This invention fills the gap in current finite element models for cyclists, particularly in providing a biomimetic model of cyclist injury with detailed anatomical structure that conforms to the physical characteristics of the 50th percentile male in China. By analyzing the injury mechanism and response of cyclists, it can provide a theoretical basis for optimizing cyclist safety protection systems and has broad application prospects in improving the safety protection level of vulnerable road users in my country.

[0038] Furthermore, the biomimetic damage model constructed in this invention is applicable to bicycle-vehicle collision scenarios. This model can serve as a core component of a digital human body platform, supporting the ergonomic optimization design of personalized cycling equipment (such as helmets, protective gear, and bicycle seats), as well as biomechanical research on the impact of cycling posture on sports injury risk. This will provide technical support in multiple fields such as traffic safety, sports medicine, and intelligent mobility, significantly enhancing my country's independent innovation capabilities and international standard discourse power in the field of vulnerable road user protection. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a diagram illustrating the ISO standard riding posture.

[0041] Figure 2 This is a schematic diagram of the method for extracting lower limb angles.

[0042] Figure 3 This is a schematic diagram illustrating the method for calculating the center of rotation of the hip joint.

[0043] Figure 4 This is a schematic diagram illustrating the method for calculating the center of rotation of the knee joint.

[0044] Figure 5a This is a schematic diagram of the method for adjusting the torso to a 10° forward tilt posture.

[0045] Figure 5b This is a schematic diagram of the method for adjusting the torso to a 30° forward tilt posture.

[0046] Figure 6a This is a schematic diagram of the extraction of the three-segment geometric reference line of the upper limb in CAD software.

[0047] Figure 6b This is a schematic diagram of importing the three-segment geometric reference line of the upper limb into the preprocessing software.

[0048] Figure 7a This is a schematic diagram of the registration of the three-segment geometric reference line of the upper limb with the handlebars.

[0049] Figure 7b A schematic diagram showing the registration of the three-segment geometric reference line of the upper limb with the finite element model of the upper limb.

[0050] Figure 8a A schematic diagram of a 10° forward-leaning cycling posture for a biomimetic model of a cyclist with physical characteristics of a 50th percentile male in China.

[0051] Figure 8b A schematic diagram of a 30° forward-leaning cycling posture for a bionic model of injury in a cyclist with physical characteristics of a Chinese male at the 50th percentile.

[0052] Figure 9a A schematic diagram illustrating the application of a biomimetic model of injury in a cyclist with physical characteristics of the 50th percentile male in China in a 10° posture experiment during vehicle collision simulation.

[0053] Figure 9b A schematic diagram illustrating the application of a biomimetic model of injury in a cyclist with physical characteristics of the 50th percentile male in China in a 30° posture experimental setup during vehicle collision simulation.

[0054] Figure 10a A schematic diagram of the von Mises stress cloud map of the head of a bionic model of injury in a cyclist with physical characteristics of the 50th percentile male in China.

[0055] Figure 10b A schematic diagram of the head shear stress cloud map for a bionic model of injury in a cyclist with physical characteristics of the 50th percentile male in China.

[0056] Figure 10c A schematic diagram of the maximum principal strain in the head of a bionic model of a cyclist with physical characteristics of the 50th percentile male in China. Detailed Implementation

[0057] The invention will be further described in detail below with reference to the specific embodiments and accompanying drawings. Except for the specific details mentioned below, the processes, conditions, and experimental methods for implementing this invention are all common knowledge and general knowledge in the art, and this invention does not have any particular limitations.

[0058] This invention provides a method for constructing a biomimetic model of cyclist injury with physical characteristics of a Chinese male at the 50th percentile. This method uses a standing injury biomimetic model with physical characteristics of a Chinese male at the 50th percentile as a baseline model. The baseline model is initially in a neutral standing posture. To ensure the model accurately reflects the cyclist's posture, systematic adjustments are needed to the direction of skeletal movement, joint rotation centers, and the geometric continuity of soft tissues in various parts of the model. This invention provides a complete posture adjustment method, enabling the final model to simultaneously possess both the cycling posture defined by ISO and human biomechanical characteristics. The specific ISO cycling posture definition is as follows: Figure 1 As shown. Figure 1 In the middle: 0-Center of bicycle bottom bracket; 1-Center of front wheel; 2-Center of rear wheel; 3-Front top tube node; 4-Rear top tube node; 5-Handlebars; 6-Saddle; 7-Left foot edge; 8-Right foot edge; 9-Left knee point; 10-Right knee point; A-Torso angle.

[0059] The construction method proposed in this invention includes the following:

[0060] (1) Definition method of joint coordinate system and rotation center of skeletal system

[0061] In the posture construction process, the selection of the joint rotation center is crucial in determining the direction of skeletal movement and the rationality of soft tissue deformation. Based on the skeletal geometry, the ND_R_BD command under the LS-DYNA panel of ANSA software was used to calculate the rotation center positions of the hip and knee joints. The hip joint consists of the femoral head and the acetabulum, with the femoral head being approximately spherical. By extracting the left and right femoral head nodes, the ND_R_BD command under the LS-DYNA panel in ANSA software was used to fit a sphere and calculate its geometric center, obtaining the coordinates of the center of the left and right femoral heads. By connecting the two centers and taking the midpoint, the overall hip joint rotation center was determined, ensuring that the lower limb rotation movement is consistent with the actual movement relationship of the acetabulum and femur. The calculated rotation center is shown below. Figure 3 As shown.

[0062] The knee joint has a complex structure, involving the femoral condyle, tibial condyle, and patella. By extracting the patellar node, femoral condyle node, and tibial condyle node, and calculating their geometric centers separately, a three-point combination center is formed to fit the direction of the knee joint rotation axis. The calculated knee joint rotation center is shown below. Figure 4 As shown. Next, by selecting the proximal and distal ends of the tibia, the centers of both are calculated. Using the Curves command in the TOPO module, a line connecting these two points and its extension are constructed, extending to the intersection of the projection point on the sole plane and the outer edge contour line of the sole to determine the foot's lower edge point. This ensures that subsequent posture adjustment points are consistent with the ISO standard. Based on the definition of the above rotation center points, subsequent posture adjustments are performed based on these points for rotation along the coronal axis.

[0063] (2) Lower limb posture construction method based on ISO standard cycling posture

[0064] Lower limb posture determines the cyclist's kinematic response in collision simulation. This invention determines key angle parameters of the lower limbs based on ISO standard cyclist diagrams. The angle between the thigh and the horizontal plane is obtained according to the standard diagrams. Rotational adjustment is applied to the femur through the hip joint rotation center to bring the thigh to a specified angle while maintaining its natural anatomical position in the sagittal and coronal planes. The angle between the lower leg and thigh is obtained according to ISO standard diagrams, such as... Figure 2 As shown, the obtained angle data are: angle a - the angle between the left thigh and the horizontal plane is 16.25°; angle b - the angle between the right thigh and the horizontal plane is 37.17°; angle c - the angle between the left thigh and the lower leg is 69.07°; angle d - the angle between the right thigh and the lower leg is 134.23°. The lower leg position is adjusted according to the knee joint rotation center to ensure that the knee flexion and extension direction conforms to the real human body. The foot posture is determined by the contact constraint between the foot's edge and the pedal, maintaining contact between the sole of the foot and the pedal, and preserving the true geometric continuity between the tibia and the foot. After the thigh and lower leg rotate to the designated position, a geometric check is performed using the Checks command in ANSA software to eliminate bone conflicts and soft tissue penetration, and point-line-plane constraints are used to maintain the coordination of muscle and bone surface morphology. Through the above steps, a standard-defined lower limb cycling posture can be obtained.

[0065] (3) Methods for adjusting the forward-leaning posture of the torso

[0066] During cycling, the torso typically leans forward to varying degrees. The ISO standard defines cycling postures as 10° and 30°. To accurately describe these two postures, this invention adjusts the torso posture based on the hip joint rotation center. The entire torso rotates around the hip joint rotation center, with the horizontal extension of the hip joint rotation center in the coronal plane as the rotation axis. This causes the spine and thoracic structure to rotate as a whole in the sagittal plane at a set angle. To ensure that the geometric relationships between the spinal segments do not undergo non-physiological displacement after rotation, this invention uses the line connecting the first thoracic vertebra to the hip joint rotation center as a reference axis during torso rotation, constraining its angular relationship with the vertical direction. This maintains the natural physiological curvature between the cervical, thoracic, and lumbar vertebrae, effectively preventing abnormal twisting or misalignment between vertebrae. The torso posture after rotation is shown in Figure 5.

[0067] (4) Methods for constructing three-segment geometric reference lines for the upper limbs and methods for adjusting upper limb posture

[0068] A cyclist's upper limbs need to maintain a proper elbow flexion posture and a stable grip on the handlebars; therefore, the spatial relationship between the shoulder joint, elbow joint, wrist joint, and distal end of the hand has a decisive influence on the cycling posture. This invention introduces a "three-segment geometric reference line" to achieve precise positioning of the upper limb posture in spatial relationships, and calculates and adjusts the upper limb posture of the model based on the geometric reference line using the Mirror 3point Plane command. The upper limb reference line is formed by connecting the following key points: the center of the shoulder joint, the center of the elbow joint, the center of the wrist joint, and the distal end of the hand. The posture image information of the cyclist's upper limbs under actual cycling conditions is obtained, and the upper limb cycling posture image is imported into CATIA software. The spline curve command is used to select the three segments of curves: the upper arm segment, the forearm segment, and the hand segment. The extracted three-segment curve is shown below. Figure 6a As shown. These three line segments are used to define the upper limb posture. After the hand segment is registered with the bicycle handlebar position, the upper limb finite element model is positioned and moved to adjust the model's posture.

[0069] To ensure positioning accuracy, this invention scales the extracted three line segments based on upper limb data from a benchmark model. The scaling factor is calculated by dividing the anatomical length (including upper arm, forearm, and hand length) of the corresponding upper limb three-segment geometric reference line in the original model by the 50th percentile male in China. The reference line is imported into ANSA software, ensuring the shoulder joint center of the reference line coincides with the shoulder joint center point in the human finite element model. The scaling factor is then input into the Scale command in ANSA software to scale the three curve segments. Figure 6b As shown. After scaling the guide line, rotate its spatial position to position the hand segment on the bicycle handlebars, as shown. Figure 7a As shown. Reference line positioning involves establishing a three-point spatial constraint between the distal fingertip, the center of the wrist joint, and the handlebar contact point. After reference line positioning, the ONCOG-Edges command in ANSA software is used to generate midpoints in the middle of the three reference lines. The upper arm, forearm, and hand are selected respectively, and the Symmetry-Mirror 3-point Plane command is used to position the upper limb finite element model to the reference line positions, thus completing the upper limb adjustment. Figure 7b As shown. After completing the three-point registration, check for any penetration between the hand and the handlebars, and make minor adjustments by rotating the hand to resolve the penetration issue. The final position of the hand drives the positional changes of the forearm and upper arm segments, so that the entire upper limb presents a natural riding grip posture at the shoulder, elbow, and wrist joint levels, thus completing the adjustment of the upper limb model.

[0070] (5) Methods for handling geometric constraints on the continuity of soft tissues of limbs

[0071] During the construction of upper and lower limb postures, soft tissues such as the quadriceps, hamstrings, and subcutaneous fat deform due to changes in the position of the femur and tibia. Without proper geometric constraints, these soft tissues may experience undue stretching or folding. This invention achieves soft tissue continuity through the following steps: For muscles on the flexed side, morphological reconstruction is performed; for distal muscles connected to the skeleton, volume is compressed while density is increased to ensure quality. For muscles involving interference and penetration, the outermost hexahedral mesh is removed, and the Solid facets command is used to reconstruct a pentahedral mesh in the removed portion, ensuring no penetration in the initial model state and that the appearance conforms to biomechanical characteristics. For muscles on the extended side, the mesh is stretched and the mesh count is increased at the muscle ends connecting to the skeleton to ensure biomechanical properties. Tendons at joints are reconstructed using Shell units, and ligaments are reconstructed using a hybrid Shell and Solid approach to ensure geometric constraints and continuity of the limb.

[0072] After fixing the spatial positions of bones and muscles, a fat lining is constructed. Using the Solid Builder command, fat cells are generated at the knee and hip joints. Shell cells are then generated on these fat cells to reconstruct the skin. Connections between any two layers are made using a shared-node approach, with shared nodes and spatial geometry constraining the relative displacement between soft tissue and bone. After reconstruction, a mesh penetration check is performed on the reconstructed portion. The Intersections command in ANSA software is used to calculate and check the penetration between bones and muscles, between bones / muscles and ligaments / tendons, and between muscles and fat.

[0073] (6) Methods for morphological verification and pre-collision inspection of the whole skeleton, muscles and soft tissues

[0074] After adjusting the posture of the upper limbs, lower limbs, and trunk, it is necessary to verify the overall skeletal structure, muscle tissue distribution, and skin morphology to ensure that the model is free of geometric anomalies or non-physiological deformations before collision simulation. This invention completes the verification through the following steps: integrating the adjusted upper limbs, trunk, and lower limbs; reconstructing the tendons, ligaments, fat, and skin at the junctions of the three parts; reconstructing the tendons and ligaments using the Face New command under the TOPO module in ANSA software; and reconstructing the fat using Solid Build. l The `der` command is used for reconstruction. After soft tissue reconstruction, the `Intersections` command is used to check for penetration between the three sections. If penetration is found, the `Execute-Fix` command is used to repair it while ensuring the correct position. A second check is then performed to ensure there is no penetration between two adjacent sections. After the check passes, the biomimetic model of a cyclist's injury with physical characteristics of a 50th percentile male in China is obtained. Figure 8a , Figure 8b As shown.

[0075] Example

[0076] This embodiment demonstrates the application of the damage biomimetic model provided by this invention in a typical vehicle collision scenario, including simulation analysis processes at different velocities under two torso angles, such as... Figure 9a , Figure 9b As shown. The vehicle model can be a sedan, SUV, or MPV, with the front-end structure using a simplified FE model or a real body structure model. The cyclist model is placed in front of the vehicle's direction of motion, and the collision speed is set according to the collision conditions: 20km / h-50km / h; the cyclist posture is selected with a 10° and 30° torso forward lean angle. The collision simulation preprocessing uses ANSA software, and the calculation uses the LS-DYNA solver. The Single Surface command is used to set the cyclist's self-contact; the Surface to Surface command is used to set the contact between the bicycle and the cyclist, the cyclist and the vehicle, the bicycle and the vehicle, the bicycle, the cyclist, and the vehicle and the ground. The coefficient of friction between the bicycle tires, vehicle tires, and the ground is set to 0.58, and a gravity field is applied to ensure the accuracy of the initial simulation conditions. The Spherical connection command is applied to the cyclist's hands, and the connection value is input to simulate the cyclist's grip force on the bicycle handlebars. After conducting a frontal collision simulation test of the cyclist, key biomechanical indicators of the cyclist model under different postures are extracted, including... Figure 10a , Figure 10b , Figure 10c The schematic diagram of the head biomechanical response shown provides a quantitative basis for the analysis of damage mechanisms and influencing factors.

[0077] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0078] As used in this invention, the term "comprising" is an open-ended expression, meaning it includes the contents specified in this invention but does not exclude other aspects.

[0079] As used in this invention, the term "and / or" includes any one or more of the related listed items and all combinations thereof.

[0080] The scope of protection of this invention is not limited to the above embodiments. Any variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of the inventive concept are included in this invention and are protected by the appended claims.

Claims

1. A method for constructing a biomimetic model of injury in a cyclist with physical characteristics of the 50th percentile male in China, characterized in that, The specific steps of the construction method are as follows: Step A: Using a standing injury bionic model with physical characteristics of the 50th percentile male in China as the baseline model, determine the center of rotation of the hip joint, the center of rotation of the knee joint, and the foot edge point. Step B: Adjust the lower limb finite element model of the reference model according to the standard riding posture so that the posture of the lower limb finite element model satisfies the spatial geometric relationship corresponding to the standard riding posture; Step C: Using the center of hip joint rotation as the center, adjust the forward tilt angle of the trunk in the sagittal plane of the human body so that the trunk of the reference model conforms to the forward tilt angle of the trunk in the standard riding posture, and ensure that the continuous geometric relationship of the spinal segments is not disrupted. Step D: Construct a three-segment geometric reference line for the upper limb using the shoulder joint, elbow joint, wrist joint, and distal end of the hand. Scale the three-segment geometric reference line for the upper limb according to the upper limb proportion of the 50th percentile male in China. Register the distal end of the hand with the handlebar contact point to achieve posture adjustment of the upper limb finite element model of the reference model. Step E: Integrate the adjusted upper limb, lower limb, and trunk postures with the rest of the baseline model, and adjust the whole-body soft tissue continuity of the model; Step F: Check and adjust the penetration problem to obtain a biomimetic model of injury of a cyclist with physical characteristics of a Chinese male at the 50th percentile.

2. The construction method as described in claim 1, characterized in that, The standing posture model with the physical characteristics of the 50th percentile male is the Tust 50th percentile male standing posture model. And / or, The standard riding posture is the standard riding posture in the international standard ISO 19206-4:2020; And / or, The hip joint rotation center is determined by calculating the geometric center of the left and right femoral head spherical surfaces and taking the midpoint of the line connecting the two points. And / or, The knee joint rotation center is calculated based on the three-dimensional geometric center points of the patella, femoral condyle, and tibial condyle. And / or, The foot edge point is determined by the intersection of the projection point of the extended longitudinal axis of the tibia onto the sole plane and the outer edge contour line of the sole, so that the selection of this point is consistent with the standard riding posture.

3. The construction method as described in claim 1, characterized in that, In step B, the spatial geometric relationship corresponding to the standard riding posture is obtained by three-dimensional geometric analysis of the line formed by the hip joint, knee joint and the foot edge point in the standard riding posture, so as to ensure the objectivity and repeatability of posture acquisition. And / or, When constraining the angle of lower limb posture, geometric continuity constraints are applied to the connection relationship between the femur, tibia and related soft tissues, so that the flexion and extension posture maintains the rationality of soft tissue deformation while maintaining the true axis of rotation.

4. The construction method as described in claim 1, characterized in that, Step B includes the following sub-steps: Step B1: Based on the standard riding posture, obtain the angle between the thigh and the horizontal plane, the angle between the thigh and the lower leg, and combine the hip joint rotation center, knee joint rotation center and the foot edge point to perform preliminary constraints on the lower limb segment; Step B2: Based on the lower limb coordinates of the standard cycling posture, further adjust the lower limb posture and impose coordinate space constraints so that the lower limb posture meets the spatial geometric relationship corresponding to the cycling posture, and its biomechanical rotation axis is consistent with that of the real human body.

5. The construction method as described in claim 4, characterized in that, The angle between the thigh and the horizontal plane refers to the angle between the line connecting the center of rotation of the knee joint and the center of rotation of the hip joint and the horizontal direction; the angle between the thigh and the lower leg refers to the angle between the line connecting the center of rotation of the knee joint and the foot edge and the line connecting the center of rotation of the knee joint and the center of rotation of the hip joint.

6. The construction method as described in claim 1, characterized in that, In step D, the upper limb three-segment geometric reference line is composed of three spatial curves formed by connecting the three-dimensional coordinates of the shoulder joint, elbow joint, wrist joint and distal end of the hand in sequence. It is used to limit the movement direction of the upper limb bone segments and ensure their biomechanical accuracy. And / or, The scaling factor of the three-segment geometric reference line for the upper limb is calculated by dividing the anatomical length of the upper arm, forearm, and hand of the 50th percentile male in China by the length of the corresponding part of the three-segment geometric reference line. And / or, The registration of the distal end of the hand with the handlebar contact point creates a three-point spatial constraint between the distal end of the fingers, the wrist joint, and the handlebar contact point, thereby limiting the positions of the elbow and shoulder joints to achieve the upper limb posture of a realistic grip.

7. The construction method as described in claim 1, characterized in that, When integrating the postures of the upper limbs, lower limbs, and trunk, three-dimensional posture coordination constraints are applied to the coupling relationship between the thoracic cavity, pelvis, and spinal segments to ensure the overall coherence and biomechanical authenticity of the whole body posture during cycling.

8. A biomimetic model of injury in a cyclist with physical characteristics of the 50th percentile male in China, characterized in that, The injury bionic model is constructed using the method described in any one of claims 1-7; the injury bionic model conforms to the standard cycling posture requirements specified in the international standard ISO 19206-4:2020 in terms of geometric shape, joint spatial position and limb posture angle.

9. A biomimetic model of cyclist injury with physical characteristics of a Chinese 50th percentile male, as described in claim 8, characterized in that, The spatial positions of the thigh and calf of the bionic model of the injury are adjusted according to the standard riding posture to ensure that the posture meets the standard requirements; the contact position between the lower edge of the foot and the ground conforms to the geometric relationship of shoe-pedal contact in the standard riding posture; the upper limb posture is calibrated according to real riding data to ensure that the spatial distribution of the shoulder, elbow and wrist joints is consistent with the real riding state. And / or, The angle between the left thigh and the horizontal plane of the damaged bionic model is 16.25°; the angle between the right thigh and the horizontal plane of the damaged bionic model is 37.17°; the angle between the left thigh and the lower leg of the damaged bionic model is 69.07°; and the angle between the right thigh and the lower leg of the damaged bionic model is 134.23°. And / or, The angle between the line connecting the centroid of the first thoracic vertebra and the rotation center of the hip joint in the biomimetic model of the injury and the vertical direction is 10° or 30°. And / or, The biomimetic damage model has complete anatomical details, including multiple tissue layers such as bones, muscles, ligaments, tendons, fat and skin. The tissues are connected by common nodes and maintain biomechanical continuity, making it suitable for high-precision collision simulation analysis. The model is applicable to collision simulation under different vehicle speeds, collision angles and collision types, and can be used to assess the risk of injury to the rider's head, neck, chest, abdomen and limbs.

10. The application of a biomimetic model of cyclist injury with physical characteristics of a Chinese 50th percentile male as described in claim 8 or 9 in biomechanical response analysis.

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