3D printed scoliosis orthosis and design method

Abstract

The invention relates to a 3D printed scoliosis orthosis and a design method, and belongs to the technical field of medical instruments, the 3D printed scoliosis orthosis comprises a body, the body is provided with three sets of auxiliary correction ribs, two kinds of auxiliary correction ribs are located on the same side, and the last set of auxiliary correction ribs is located on the other side and located between the two kinds of auxiliary correction ribs. The auxiliary correcting tendon adopts a three-point force system, and the local force pair system and sagittal plane spine balance is achieved. The'three-point force system 'refers to the stress condition of three points on the same plane but not on the same straight line, when the stress direction of one point is opposite to that of the other two points, the three-point force interacts to generate a correction effect according to the acting force, the counter-acting force, the force decomposition law and the lever balance principle, and the correction effect is achieved. During design, through accurate force application position, reasonable force application size and proper force application area selection, the scoliosis condition of a patient can be remarkably improved, and the requirement for surgical intervention is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a 3D printed scoliosis orthosis and a design method thereof. Background Art

[0002] Scoliosis refers to a three-dimensional deformity of the spine caused by one or more segments of the spine deviating from the midline of the body in the coronal plane and bending sideways, usually accompanied by spinal rotation. Scoliosis is usually divided into functional scoliosis and structural scoliosis. The latter is further divided into idiopathic scoliosis with uncertain causes and non-specific scoliosis caused by metabolic, congenital and other diseases. Among them, idiopathic scoliosis accounts for about 80% of the total.

[0003] Scoliosis not only causes aesthetic defects, but also affects the physical and mental health of adolescents. Scoliosis affects the patient's respiratory function, damages the growth and development of the adolescent's lungs, hinders chest movement, and affects the patient's gas exchange and ventilation functions. Statistics show that this disease accounts for about 0.5% to 3% of the total number of adolescents, of which about 10% require surgical treatment, and the rest require scoliosis orthoses for treatment. The quality of the orthosis design determines the treatment effect.

[0004] Orthotics are currently considered the only effective non-surgical treatment for early scoliosis. Conventional scoliosis orthotics are standardized products, produced by manufacturers in different sizes, and patients choose the appropriate model to wear according to the shape of their spine. However, this mass-produced standardized orthosis is only suitable for 70% of scoliosis patients, while the remaining scoliosis patients need personalized scoliosis orthotics designed according to their spine shape. Existing methods for making personalized scoliosis orthotics usually use plaster molding to make a plaster model of the patient, then manually shape the plaster model, and finally use vacuum low-pressure molding to make the orthosis. This production method requires manual shaping to achieve spinal correction, so that the correction effect often depends on the experience of the technician, and there are problems of time-consuming and labor-intensive. Summary of the invention

[0005] The present invention aims to solve the above-mentioned technical problems and provides a 3D printed scoliosis orthosis and a design method.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0007] A 3D printed scoliosis orthosis, comprising a body, wherein when a patient wears the scoliosis orthosis, the body wraps around the patient's torso;

[0008] The main body is provided with three groups of auxiliary correction ribs, two of which are on the same side, and the last group of which is located on the other side and between the two auxiliary correction ribs.

[0009] Preferably, one side of the body is open, and a Velcro strip for tightening is installed at the opening.

[0010] Preferably, the main body has a plurality of hollow holes, and the main body has a plurality of exhaust holes.

[0011] Preferably, the body is made of polylactic acid with a density of 1.25-1.28 g / cm 3 .

[0012] A design method for a 3D printed scoliosis orthosis comprises the following steps:

[0013] S1. Data collection:

[0014] The CT scan images of the patients were collected, and the three-dimensional models of the trunk and the corresponding scoliosis orthosis were constructed through inverse technology to obtain the three-dimensional model of the body surface and the three-dimensional model of the spine.

[0015] S2. Finite element analysis:

[0016] Finite element analysis is performed on the three-dimensional model of the body surface and the three-dimensional model of the spine to predict the orthopedic effect after the human body wears it and optimize the design.

[0017] S3. Stress analysis:

[0018] The central vertical line of the spine of the patient's CT scan image is the y-axis, the central projection line of the spine is the S-line, the convex position of the S-line and the y-axis is determined, the longest distance between the convex position and the S-line is C, and the position of the auxiliary correction muscle acting on the convex position is determined, and the extrusion elastic force of the auxiliary correction muscle is

[0019]

[0020] S4. Orthopedic force loading:

[0021] Design the structure of the orthosis to ensure that the correction force can be accurately loaded to the apex and end point of the scoliosis;

[0022] S5. Verification and adjustment:

[0023] Through finite element simulation calculation and analysis, the loading effect of the correction force is verified, and adjustments are made based on the results to ensure that the orthosis conforms to the patient's scoliosis curve;

[0024] S6, 3D printing:

[0025] The model is printed by a 3D printer using polylactic acid as the material to obtain the main body;

[0026] S7. Body Verification:

[0027] The shape error of the body is detected and adapted to the patient.

[0028] Preferably, the thickness of the scoliosis orthosis printed by the 3D printer is 3 mm, 3.5 mm, 4 mm or 4.5 mm.

[0029] Preferably, f is a coefficient, E is an elastic modulus, and p is a strain of the material.

[0030] Preferably, the value of f is 0.85-0.92.

[0031] Preferably, the extrusion elastic force of the other two auxiliary correction ribs is 0.2-0.5 times of F.

[0032] After adopting the above structure, the present invention has the following advantages:

[0033] The auxiliary correction ribs of the present invention adopt a "three-point force system", a local "force pair system" and sagittal plane spinal balance. The "three-point force system" refers to the force conditions of three points in the same plane but not in the same straight line. When the force direction of one point is opposite to that of the other two points, the three-point forces interact with each other to produce a corrective effect according to the action and reaction force, the law of force decomposition and the principle of lever balance. The present invention can significantly improve the patient's scoliosis and reduce the need for surgical intervention through precise force application position, reasonable force application size and appropriate force application area selection during design.

[0034] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a schematic diagram of the structure of the present invention;

[0037] Figure 2 is a schematic diagram of scoliosis forces of the present invention;

[0038] Figure 3 is a graph of scoliosis of the present invention;

[0039] Figure 4 It is a schematic diagram of the force acting on the spine of the present invention;

[0040] Figure 5 It is a design flow chart of the present invention.

[0041] As shown in the figure: 1. Main body; 2. Auxiliary correction ribs; 3. Velcro; 4. Hollow holes; 5. Exhaust holes. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0043] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] The present invention is further described in detail below in conjunction with the full text.

[0045] Combined with Figure 1-Figure 5 , a 3D printed scoliosis orthosis, comprising a body 1, when a patient wears the scoliosis orthosis, the body 1 wraps around the patient's torso;

[0046] The main body 1 has three groups of auxiliary correction ribs 2 , two of the auxiliary correction ribs 2 are on the same side, and the last group of the auxiliary correction ribs 2 is located on the other side and between the two auxiliary correction ribs 2 .

[0047] One side of the body 1 is open, and a Velcro 3 for tightening is installed at the opening.

[0048] The main body 1 has a plurality of hollow holes 4 , and the main body 1 has a plurality of exhaust holes 5 .

[0049] The body 1 is made of polylactic acid with a density of 1.25-1.28 g / cm 3 .

[0050] A design method for a 3D printed scoliosis orthosis comprises the following steps:

[0051] S1. Data collection:

[0052] Collect the patient's CT scan images, and use the reverse technology to construct a three-dimensional model of the trunk and the corresponding scoliosis orthosis to obtain a three-dimensional model of the body surface and a three-dimensional model of the spine. Specifically, the patient's spine and trunk data are obtained through CT scanning, three-dimensional human body scanning system and other technologies. Three-dimensional modeling: Import CT or MRI data into medical image processing software for three-dimensional reconstruction. This step can generate a three-dimensional structural model of hard tissue and soft tissue. A three-dimensional scanner can be used to obtain the patient's body surface point cloud data and construct a three-dimensional model of the patient's body surface.

[0053] S2. Finite element analysis:

[0054] Finite element analysis is performed on the three-dimensional model of the body surface and the three-dimensional model of the spine to predict the orthopedic effect after the human body wears it and optimize the design.

[0055] S3. Stress analysis:

[0056] The center vertical line of the spine of the patient's CT scan image is the y-axis, the center projection line of the spine is the S line, the convex position of the S line and the y-axis is determined, the longest distance between the convex position and the S line is C, and the position of the auxiliary correction rib 2 acting on the convex position is determined, and the extrusion elastic force of the auxiliary correction rib 2 is

[0057] S4. Orthopedic force loading:

[0058] Design the structure of the orthosis to ensure that the correction force can be accurately loaded to the apex and end point of the scoliosis;

[0059] S5. Verification and adjustment:

[0060] Through finite element simulation calculation and analysis, the loading effect of the correction force is verified, and adjustments are made based on the results to ensure that the orthosis conforms to the patient's scoliosis curve;

[0061] S6, 3D printing:

[0062] A 3D printer using polylactic acid as the material is used to print the model to obtain a body 1;

[0063] S7. Body Verification:

[0064] The shape error of the body 1 is detected and adapted to the patient.

[0065] The thickness of the scoliosis orthosis printed by the 3D printer is 3 mm, 3.5 mm, 4 mm or 4.5 mm.

[0066] f is the coefficient, E is the elastic modulus, and p is the strain of the material.

[0067] The value of f is 0.85-0.92.

[0068] The extrusion elastic force of the other two auxiliary correction ribs 2 is 0.2-0.5 times of F. Specifically, the auxiliary correction ribs 2 of the present invention adopt a "three-point force system", a local "force pair system" and sagittal plane spinal balance. The "three-point force system" refers to the force conditions of three points that are in the same plane but not in the same straight line. When the force direction of one point is opposite to that of the other two points, the three-point forces interact with each other to produce a corrective effect according to the action and reaction force, the law of force decomposition and the principle of lever balance. The "force pair system" consists of two forces in opposite directions, which are applied to a wider part of the trunk from different directions to cause it to rotate (i.e., local rotation). The "force pair system" must be applied to the level of the top vertebra where the vertebra rotates the most to maximize the force.

[0069] In the specific implementation of the present invention, the main material of the 3D printer is PLA (polylactic acid). Also known as polylactide, it is a polyester polymer obtained by polymerization of lactic acid as the main raw material. It is a new type of biodegradable material. Molecular formula: (C3H4O2)n, density: 1.25 to 1.28g / cm 3 , melting point 176℃.

[0070] Polylactic acid has good thermal stability, a processing temperature of 170-230°C, good solvent resistance, and can be processed in a variety of ways, such as extrusion, spinning, biaxial stretching, and injection blow molding. In addition to being biodegradable, products made of polylactic acid have good biocompatibility, gloss, transparency, feel, and heat resistance.

[0071] It has the following advantages:

[0072] 1) Polylactic acid (PLA) is a new type of biodegradable material, made from starch raw materials from renewable plant resources (such as corn). Starch raw materials are saccharified to obtain glucose, which is then fermented with glucose and certain strains to produce high-purity lactic acid, and then polylactic acid of a certain molecular weight is synthesized by chemical synthesis. It has good biodegradability and can be completely degraded by microorganisms in nature after use, eventually generating carbon dioxide and water without polluting the environment. This is very beneficial to protecting the environment and is a recognized environmentally friendly material. The treatment method for ordinary plastics is still incineration, which causes a large amount of greenhouse gases to be discharged into the air, while polylactic acid plastics are buried in the soil for degradation, and the carbon dioxide produced directly enters the soil organic matter or is absorbed by plants, and will not be discharged into the air, and will not cause a greenhouse effect.

[0073] 2) Good mechanical and physical properties. Polylactic acid is suitable for various processing methods such as blow molding and thermoplastics. It is easy to process and widely used. It can be used to process various plastic products from industrial to civilian use, packaged food, fast food lunch boxes, non-woven fabrics, industrial and civilian fabrics. It can then be processed into agricultural fabrics, health fabrics, rags, sanitary products, outdoor UV protection fabrics, tent fabrics, floor mats, etc. The market prospects are very promising.

[0074] 3) Good compatibility and degradability. Polylactic acid is also widely used in the medical field, such as producing disposable infusion equipment, non-disassembly surgical sutures, etc., and low-molecular polylactic acid as a drug sustained-release packaging agent.

[0075] 4) In addition to the basic properties of biodegradable plastics, polylactic acid (PLA) also has its own unique properties. The strength, transparency and resistance to climate change of traditional biodegradable plastics are not as good as those of ordinary plastics.

[0076] 5) The basic physical properties of polylactic acid (PLA) are similar to those of petrochemical synthetic plastics, which means that it can be widely used to manufacture various application products. Polylactic acid also has good gloss and transparency, which is comparable to the film made of polystyrene, which is something that other biodegradable products cannot provide.

[0077] 6) Polylactic acid (PLA) has the best tensile strength and ductility. It can also be produced by various common processing methods, such as melt extrusion molding, injection molding, blown film molding, foam molding and vacuum molding. It has similar molding conditions as widely used polymers. In addition, it also has the same printing performance as traditional films. In this way, polylactic acid can be made into a variety of application products to meet the needs of different industries.

[0078] 7) Polylactic acid (PLA) film has good air permeability, oxygen permeability and carbon dioxide permeability, and it also has the property of isolating odors. Viruses and molds easily attach to the surface of biodegradable plastics, so there are concerns about safety and hygiene. However, polylactic acid is the only biodegradable plastic with excellent antibacterial and antifungal properties.

[0079] 8) When incinerating polylactic acid (PLA), its calorific value is the same as that of incinerating paper, which is half of that of incinerating traditional plastics (such as polyethylene), and incinerating polylactic acid will never release toxic gases such as nitrides and sulfides. The human body also contains lactic acid in monomer form, which shows the safety of this decomposable product.

[0080] Due to the above excellent comprehensive performance, it is called "amazing plastic" by European and American countries and is highly valued and widely used in many industries.

[0081] (1) Physical properties:

[0082] Density: 1.25-1.28g / cm3;

[0083] Melting point: 176°C;

[0084] Intrinsic viscosity IV: 0.2-8dL / g;

[0085] Glass transition temperature: 60-65°C;

[0086] Heat transfer coefficient: 0.025λ(w / m·k);

[0087] (2) Mechanical properties:

[0088] Tensile strength: 40-60MPa;

[0089] Elongation at break: 4%-10%;

[0090] Elastic modulus: 3000-4000MPa;

[0091] Flexural modulus: 100-150MPa;

[0092] Izod impact strength (unnotched): 150-300 J / m;

[0093] Izod impact strength (notched): 20-60J / m;

[0094] Rockwell hardness: 88;

[0095] (3) Features:

[0096] 1). Biodegradability

[0097] Compared with traditional plastics, polylactic acid can be degraded into CO2 and H2O by microorganisms, light, etc. Its degradation products are non-toxic and harmless and will not pollute the environment. The monomer for producing polylactic acid is lactic acid, which can be produced by fermentation of crops or agricultural by-products such as wheat, rice and beets. Therefore, the raw materials for producing polylactic acid are renewable. As an emerging biodegradable material, polylactic acid has extremely wide applications.

[0098] 2). Biocompatibility and absorbability

[0099] Polylactic acid can be hydrolyzed by acid or enzymes to generate lactic acid in the human body. As a metabolic product of cells, lactic acid can be further metabolized by enzymes in the body to generate CO2 and H2O. Therefore, polylactic acid is non-toxic and harmless to the human body and has good biocompatibility and bioabsorbability. Polylactic acid has been certified by the U.S. Food and Drug Administration and can be used as a biomaterial implanted in the human body.

[0100] 3). Physical processability

[0101] As a thermoplastic polymer material, polylactic acid has good plasticity and physical processing properties, high melting point and crystallinity, good elasticity and flexibility, and excellent thermoforming properties. Like other polymer materials such as polypropylene (PP), polystyrene (PS) and polyphenylene ether resin (PPO), polylactic acid materials can be processed by extrusion, stretching and injection blow molding.

[0102] In the biomedical field, polylactic acid materials can be used as drug delivery materials, tissue engineering scaffold materials, bone repair materials, etc. The medical field is an early application field of PLA and its composites. At present, extensive basic research and clinical applications have been carried out in the fields of orthopedic surgery, thoracic surgery, maxillofacial surgery, and targeted treatment of tumors.

[0103] Embodiment 1:

[0104] A patient with S-shaped scoliosis in the upper thoracic region was selected. He was 9 years old and weighed 30 kg. Scoliosis occurred in the cervical and lumbar vertebrae, with the most severe deformation in the thoracic and cervical vertebrae, and the shape of the area below the vertebral body was normal.

[0105] A design method for a 3D printed scoliosis orthosis comprises the following steps:

[0106] S1. Data collection:

[0107] The CT scan images of the patients were collected, and the three-dimensional models of the trunk and the corresponding scoliosis orthosis were constructed through inverse technology to obtain the three-dimensional model of the body surface and the three-dimensional model of the spine.

[0108] S2. Finite element analysis:

[0109] Finite element analysis is performed on the three-dimensional model of the body surface and the three-dimensional model of the spine to predict the orthopedic effect after the human body wears it and optimize the design.

[0110] S3. Stress analysis:

[0111] The central vertical line of the spine of the patient's CT scan image is the y-axis, the central projection line of the spine is the S-line, the convex position of the S-line and the y-axis is determined, the longest distance between the convex position and the S-line is C, and the position of the auxiliary correction rib 2 acting on the convex position is determined, and the extrusion elastic force of the auxiliary correction rib 2 is F=212N;

[0112] S4. Orthopedic force loading:

[0113] Design the structure of the orthosis to ensure that the correction force can be accurately loaded to the apex and end point of the scoliosis;

[0114] S5. Verification and adjustment:

[0115] Through finite element simulation calculation and analysis, the loading effect of the correction force is verified, and adjustments are made based on the results to ensure that the orthosis conforms to the patient's scoliosis curve;

[0116] S6, 3D printing:

[0117] The model is printed by a 3D printer using polylactic acid as the material to obtain a body 1, and the thickness of the body 1 is 3 mm;

[0118] S7. Body Verification:

[0119] The shape error of the body 1 was detected and the patient was fitted. The stress of the orthosis was mainly concentrated in the upper chest, which was consistent with the actual situation that scoliosis occurred in the upper thoracic segment. No excessive bending stress occurred locally.

[0120] Embodiment 2:

[0121] A scoliosis patient (14 years old, S-type scoliosis, thoracic Cobb angle 10°, lumbar Cobb angle 13°) was selected.

[0122] A design method for a 3D printed scoliosis orthosis comprises the following steps:

[0123] S1. Data collection:

[0124] The CT scan images of the patients were collected, and the three-dimensional models of the trunk and the corresponding scoliosis orthosis were constructed through inverse technology to obtain the three-dimensional model of the body surface and the three-dimensional model of the spine.

[0125] S2. Finite element analysis:

[0126] Finite element analysis is performed on the three-dimensional model of the body surface and the three-dimensional model of the spine to predict the orthopedic effect after the human body wears it and optimize the design.

[0127] S3. Stress analysis:

[0128] The central vertical line of the spine of the patient's CT scan image is the y-axis, the central projection line of the spine is the S-line, the convex position of the S-line and the y-axis is determined, the longest distance between the convex position and the S-line is C, and the position of the auxiliary correction rib 2 acting on the convex position is determined, and the extrusion elastic force of the auxiliary correction rib 2 is F=212N;

[0129] S4. Orthopedic force loading:

[0130] Design the structure of the orthosis to ensure that the correction force can be accurately loaded to the apex and end point of the scoliosis;

[0131] S5. Verification and adjustment:

[0132] Through finite element simulation calculation and analysis, the loading effect of the correction force is verified, and adjustments are made based on the results to ensure that the orthosis conforms to the patient's scoliosis curve;

[0133] S6, 3D printing:

[0134] The model is printed by a 3D printer using polylactic acid as the material to obtain a body 1, and the thickness of the body 1 is 4 mm;

[0135] S7. Body Verification:

[0136] The shape error of the body 1 was detected and the patient was fitted. The stress of the orthosis was mainly concentrated in the middle spine, which was consistent with the actual situation that scoliosis occurred in the upper thoracic segment. No excessive bending stress occurred locally.

[0137] Comparative Example:

[0138] Two patients similar to Example 1 and Example 2 were selected, and plaster models of the patients were made for the patients using a plaster molding method. The plaster models were then manually reshaped, and then the two patients wore the plaster models.

[0139] Four patients in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 wore the plaster models for 22 hours a day for 3 months. In the first month, the plaster models worn by Comparative Example 1 and Comparative Example 2 showed obvious discomfort, stuffiness, tight binding force and high friction to the body.

[0140] Experimental results:

[0141] Embodiment 1 Embodiment 2 Comparative Example 1 Comparative Example 2 Corrective effect Correction Correction Uncorrected Uncorrected Wearing effect suitable suitable Not suitable Not suitable

[0142] The auxiliary correction ribs of the present invention have an important impact on the correction effect of scoliosis. Through accurate force application position, reasonable force application size and appropriate force application area selection, the patient's scoliosis condition can be significantly improved and the need for surgical intervention can be reduced.

[0143] When designing the present invention, it was found that the magnitude of the orthopedic force and the selection of the force application area have a significant impact on the correction effect. The analysis emphasizes the need to consider three-dimensional factors when designing orthotics to ensure that the orthopedic force can effectively correct the rotation and displacement of the spine.

[0144] The present invention and its embodiments are described above, and such description is not restrictive. What is shown in the full text is only one of the embodiments of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. A 3D printed scoliosis orthosis, characterized in that: It comprises a body (1), and when the patient wears the scoliosis orthosis, the body (1) wraps around the patient's torso; The main body (1) is provided with three groups of auxiliary correction ribs (2), two of the auxiliary correction ribs (2) are on the same side, and the last group of the auxiliary correction ribs (2) is located on the other side and between the two auxiliary correction ribs (2).

2. A 3D printed scoliosis orthosis, characterized in that: One side of the body (1) is open, and a Velcro (3) for tightening is installed at the opening.

3. A 3D printed scoliosis orthosis, characterized in that: The main body (1) is provided with a plurality of hollow holes (4), and the main body (1) is provided with a plurality of exhaust holes (5).

4. A 3D printed scoliosis orthosis, characterized in that: The body (1) is made of polylactic acid with a density of 1.25-1.28 g / cm 3 .

5. A method for designing a 3D printed scoliosis orthosis as claimed in any one of claims 1 to 4, comprising the following steps: S1. Data collection: The CT scan images of the patients were collected, and the three-dimensional models of the trunk and the corresponding scoliosis orthosis were constructed through inverse technology to obtain the three-dimensional model of the body surface and the three-dimensional model of the spine. S2. Finite element analysis: Finite element analysis is performed on the three-dimensional model of the body surface and the three-dimensional model of the spine to predict the orthopedic effect after the human body wears it and optimize the design. S3. Stress analysis: The center vertical line of the spine of the patient's CT scan image is the y-axis, the center projection line of the spine is the S-line, the convex position of the S-line and the y-axis is determined, the longest distance between the convex position and the S-line is C, and the position of the auxiliary correction muscle (2) acting on the convex position is determined, and the extrusion elastic force of the auxiliary correction muscle (2) is S4. Orthopedic force loading: Design the structure of the orthosis to ensure that the correction force can be accurately loaded to the apex and end point of the scoliosis; S5. Verification and adjustment: Through finite element simulation calculation and analysis, the loading effect of the correction force is verified, and adjustments are made based on the results to ensure that the orthosis conforms to the patient's scoliosis curve; S6, 3D printing: A 3D printer using polylactic acid as the material is used to print the model to obtain a body (1); S7. Body Verification: The shape error of the body (1) is detected and adapted to the patient.

6. The method for designing a 3D printed scoliosis orthosis according to claim 5, characterized in that: The thickness of the scoliosis orthosis printed by the 3D printer is 3 mm, 3.5 mm, 4 mm or 4.5 mm.

7. The method for designing a 3D printed scoliosis orthosis according to claim 5, characterized in that: f is the coefficient, E is the elastic modulus, and p is the strain of the material.

8. A method for designing a 3D printed scoliosis orthosis according to claim 7, characterized in that: The value of f is 0.85-0.

92.

9. The method for designing a 3D printed scoliosis orthosis according to claim 5, characterized in that: The extrusion elastic force of the other two auxiliary correction ribs (2) is 0.2-0.5 times of F.

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