Spiral limb fracture external fixator and using method thereof

Abstract

The invention relates to the technical field of medical instruments, and particularly discloses a spiral limb fracture external fixator and a using method thereof.The silica gel air bag bandage is made of silica gel, is in a thin strip shape and is connected through a plurality of air bags, the edges of the air bags are substantial leucorrhea, the inner side and the outer side of each air bag are in special shapes, air holes are formed in the adjacent air bags, and an inflation opening is connected with an air guide pipe; and the digital display inflator pump is connected with the air guide pipe and the sensor. When in use, the sensor is attached to an affected limb, the spirally wound bandage wraps the sensor, and then the digital display inflator pump is used for inflating to a set value. The air bag is of a semicircular structure on the outer side and a trapezoidal table structure on the inner side, when the air bag bandage is wound on an affected limb, the side faces of the trapezoidal tables can be tightly attached and firmly fixed, the semicircle is pulled into a flat empty bag structure, and vibration is relieved. Under the cooperation of devices such as the digital display inflator pump and the flexible film pressure sensor, the air bag can change along with the state of the limb, continuous compression power is generated on the limb, and a patient can do some simple activities.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a spiral limb fracture external fixator and a use method thereof. Background Art

[0002] Limb fractures are a relatively common type of fracture in clinical practice, and refer to the interruption of bone connectivity in the limb bones due to accidental injuries such as falls, car accidents, and construction accidents, including periarticular fractures, upper limb fractures, lower limb fractures, and ankle fractures. Common treatments for limb fractures in clinical practice are surgical treatment and conservative treatment. Surgical treatment has good clinical effects, but it has many limitations. In clinical practice, conservative treatment is often used for patients with fractures who are not suitable for surgery. Conservative treatment methods include: plaster fixation, splint external fixation, air bag fixation, and external application of traditional Chinese medicine. The above conservative treatment methods each have their own advantages, but there are also some technical difficulties that cannot be overcome. The specific analysis is as follows:

[0003] 1. Plaster fixation

[0004] Plaster immobilization is a traditional treatment for external fixation of limb fractures. Finely powdered plaster of Paris is evenly spread on a specially prepared, thin-pore gauze to create a plaster bandage. This bandage is then soaked in warm water and applied to the affected limb. It typically hardens within 5-10 minutes and, once dry and firm, stabilizes the affected limb. As a commonly used treatment for fractures and dislocations, plaster immobilization has both unique advantages and limitations.

[0005] Through its powerful immobilization force, plaster casts ensure stability during the healing process of fractures or dislocations, preventing the risk of displacement or re-injury. Their wide applicability makes them a reliable treatment for a wide range of fractures and dislocations, making them a reliable treatment option for children and patients with difficult-to-surgical conditions. Plaster casts are relatively simple to perform, requiring no complex surgical equipment or techniques, and can be easily performed in an outpatient clinic or emergency room. Furthermore, compared to surgery and other expensive treatments, plaster casts are relatively inexpensive, making them more suitable for patients with limited financial resources and enabling more people to enjoy effective treatment. However, plaster casts also carry risks. Improper application can delay fracture healing and compromise patient safety and comfort. Common complications of plaster casts include infection, venous thromboembolism, pressure and friction injuries, paresthesia or numbness in the limbs, poor fracture fixation, soft tissue swelling, neurovascular compromise, compartment syndrome, and joint stiffness.

[0006] 2. External fixation with splint

[0007] External fixation with a splint is based on the physiological direction of the limb. The cloth tape wrapping exerts compression on the splint, the paper pad prevents or corrects the angular deformity and lateral displacement of the fracture ends, and the intrinsic power is generated during limb muscle movement, so that fracture fixation can restore the internal dynamic balance of the limb.

[0008] External splinting is convenient, economical, effective, and quick, while also offering a certain degree of toughness, elasticity, and plasticity. However, it is only suitable for simple limb fractures. Because splinting is cumbersome, the tightness of the bandage must be controlled. Too loose can fail to stabilize the fracture, while too tight can impair blood circulation. Furthermore, the tightness of the bandage must be adjusted constantly as the patient's fractured limb experiences changes in swelling. Therefore, skilled manipulation is essential.

[0009] 3. Airbag fixation

[0010] Balloon fixation stabilizes fractures through inflation. Balloon fixation is a simple and quick procedure, requiring no complex tools or procedures. Simply place the balloon at the desired location and inflate it using an inflator. It also offers excellent stability. Once inflated, the balloon generates evenly distributed pressure, effectively securing the affected limb and preventing movement or slippage. This stable fixation not only ensures accuracy and precision, but also reduces risks and improves efficiency. Balloon fixation, due to its excellent adaptability, stability, ease of use, object protection, and reusability, has gained widespread adoption and acceptance in numerous fields. It plays a vital role in industrial production, scientific research, and everyday life, bringing convenience and benefits to people's lives and work. However, it also has certain drawbacks. The material properties of the balloon are demanding, particularly at the connection points, which are susceptible to damage. If sutured with thread, pinholes can easily lead to air leakage. If glued with adhesive, the adhesive can easily delaminate, resulting in fixation failure. Furthermore, the inflation device is expensive, making it inaccessible to a wide range of patients.

[0011] 4. External application of Chinese medicine

[0012] Traditional Chinese medicine preparations used in topical application generally consist of three components: the topical herbal remedy, an excipient, and a carrier. Topical application primarily delivers the therapeutic effect. Topical application involves transdermal administration of the drug. Based on the specific condition, the appropriate drug is formulated into ointments, pills, pastes, tablets, and other formulations, which are then applied to the appropriate body surface area or acupoints. The drug penetrates the epidermis and appendages, entering the body's circulation and reaching the target site to exert its therapeutic effect. Topical application of traditional Chinese medicine is based on natural herbs, with mild ingredients, no side effects, and minimal skin irritation, ensuring patient safety. The drug penetrates the skin directly to the affected area, exerting its therapeutic effect, resulting in a more immediate effect. Furthermore, the protective film formed by the drug on the skin surface can prolong its duration of action. Clinical studies have demonstrated that topical application of traditional Chinese medicine can cool blood, reduce inflammation, activate blood circulation, and reduce adverse reactions such as redness, swelling, increased pain, and infection. While skin absorption offers certain advantages, it also has limitations. For example, for diseases requiring rapid effects, drug absorption through the skin may not be as rapid as with intravenous injections. The preparation of topical medications requires different combinations of materials depending on the fracture situation, making operation inconvenient, the formulation process complex, and the drugs prone to mold and deterioration. Different batches of raw materials and excipients can lead to different clinical effects. Most excipients use preservatives, and some traditional preservatives have certain irritants, safety risks, and allergenic properties. Topical application of Traditional Chinese Medicine also presents other challenges that need to be addressed: Drug penetration and leakage are inevitable, not only contaminating the affected area but also making daily necessities unclean and difficult to clean. Topical medications cannot be stored for long periods of time and are prone to mold, affecting drug quality.

[0013] Therefore, it is urgent to design an external fixation device for conservative treatment of fractures using medical silicone materials that has reliable fixation, good plasticity, adjustable tightness, and light material, and provide a method for its use. Summary of the Invention

[0014] The technical problem to be solved by the present invention is to provide a spiral external fixator for limb fractures and a method of use thereof, so as to solve the problems existing in existing external fixation methods for limb fractures, such as difficulty in adjusting the fixation pressure, poor air permeability, and inconvenient operation, thereby achieving uniform and stable fixation of the fracture site and improving the patient's comfort and treatment effect.

[0015] To solve the above technical problems, the present invention provides a technical solution as follows: a spiral limb fracture external fixator, comprising a silicone airbag bandage, a flexible film pressure sensor, a digital display air pump and an airway tube;

[0016] The silicone airbag bandage is made of silicone and is in the form of a thin strip, consisting of several airbags connected in sequence; the edges of the airbags are solid leucorrhea; the inner side of the airbag is trapezoidal, the outer side is a semicircular structure, and the space between the inner and outer sides is solid; ventilation holes are provided between adjacent airbags;

[0017] The silicone airbag bandage is provided with an inflation port, the inflation port is connected to the airway tube, and the digital display inflation pump is connected to the airway tube and the flexible film pressure sensor.

[0018] Furthermore, the manufacturing method of the silicone airbag bandage is as follows:

[0019] Pour equal amounts of type A and type B liquid silica gel into beakers respectively, stir with a glass rod for 3 minutes, and after thorough mixing, place the beaker containing liquid silica gel in a vacuum degassing machine and degas for 5 minutes;

[0020] Pour the degassed liquid silicone into the airbag mold, take out the finished product after curing, and check its air tightness.

[0021] Furthermore, the inflation port adopts a stainless steel SUS420 / 40CR valve.

[0022] Furthermore, the air guide tube is a silicone tube.

[0023] The present invention also provides a method for using a spiral limb fracture external fixator, comprising the following steps:

[0024] S1. Attach the flexible film pressure sensor to the affected limb, then spirally wrap a silicone airbag bandage around the affected limb to enclose the flexible film pressure sensor.

[0025] S2. Inflate the silicone airbag bandage using the digital air pump and stop when the set value is reached.

[0026] The advantages of the present invention compared with the prior art are:

[0027] 1. The medical silicone airbag with a spiral structure can gradually eliminate some adverse prognoses during the swelling and swelling reduction process of fracture healing, and can also deform according to the curve of the human body to achieve a good fixation effect.

[0028] 2. The airbag is a semicircular structure on the outside and a trapezoidal structure on the inside. When the airbag bandage is wrapped around the affected limb, the sides of the trapezoidal platform can be tightly attached to each other for a secure fixation, and the semicircle is pulled into a flat hollow structure to reduce shock.

[0029] 3. Adjacent airbags are connected by circular pores; the inner and outer airbags are separated by substantial silicone material, and the pores are not connected; the pore structure makes the changes caused by the inflation and deflation of the airbags smoother, which plays a role in reducing shock.

[0030] 4. The three-layer structure of the airbag from outside to inside is: semicircular hollow structure, silicone uniform solid structure, trapezoidal hollow structure; the middle layer's solid structure provides support for the airbag, making the airbag bandage more stable in clinical applications.

[0031] 5. A certain amount of substantial blank tape is left on the edge of the silicone airbag bandage. When wrapping, the blank tape of the next circle is pressed on the blank tape of the previous circle, which can make the airbag bandage more stable during clinical application.

[0032] 6. The present invention places an airbag in a silicone airbag bandage and inflates and deflates it through an automatic pump, making the tightness of the bandage adjustable, effectively reducing the incidence of diseases such as inflammatory exudation, compartment syndrome, and joint stiffness caused by blood circulation disorders, and can also effectively prevent complications such as pressure sores.

[0033] 7. With the cooperation of digital display air pump, flexible film pressure sensor and other devices, the present invention enables the air bag to change with the state of the limb, generate continuous compression power in the limb, and enable the patient to perform some simple activities.

[0034] 8. The silicone material used in the present invention has good air permeability, certain strength, hardness and resilience, heat and low temperature resistance, resistance to erosion by medical chemicals, and no adhesion to human tissue and blood. It has good biological adaptability, is non-toxic, odorless, and non-carcinogenic, and can ensure the safety of clinical applications.

[0035] 9. The digital display air pump and flexible film pressure sensor are cost-effective. The silicone material can be reused after sterilization and regeneration, solving the environmental pollution problem caused by the large amount of waste generated by the inability to decompose silicone materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of a silicone airbag bandage.

[0037] Figure 2 This is a production flow chart of silicone airbag bandage.

[0038] Figure 3 It is a structural diagram of a flexible film pressure sensor.

[0039] Figure 4 It is a structural diagram of a digital display air pump.

[0040] Figure 5 It is a schematic diagram of the structure of the air sac and the actual leucorrhea.

[0041] Figure 6 It is a schematic diagram of the structure of the airbag.

[0042] Figure 7 It is a schematic diagram of the structure of ventilation pores.

[0043] Figure 8 It is a schematic diagram of the connection structure between the digital display air pump and the flexible film pressure sensor.

[0044] Figure 9 The present invention is a schematic structural diagram of a spiral external fixator for limb fractures.

[0045] Figure 10 This is a diagram of a femur model.

[0046] Figure 11 This is a simplified model diagram of the femur.

[0047] Figure 12 It is a wireframe diagram of the combined model of a spiral silicone fracture external fixator.

[0048] Figure 13 This is a combined model diagram of a spiral silicone fracture external fixator.

[0049] Figure 14 This is a perspective view of a combined model of a spiral silicone fracture external fixator.

[0050] Figure 15 It is a schematic diagram of the model.

[0051] Figure 16 It is a cross-sectional deformation diagram.

[0052] Figure 17 This is a cross-sectional deformation diagram after magnification 5 times.

[0053] Figure 18 It is the displacement variation diagram along the axial direction.

[0054] Figure 19 It is the stress variation diagram along the axial direction.

[0055] Figure 20 It is the stress cloud diagram of the finite element calculation results.

[0056] Figure 21 It is the displacement cloud diagram of the finite element calculation results.

[0057] As shown in the figure: 1. Silicone airbag bandage, 2. Flexible film pressure sensor, 3. Digital air pump, 4. Airway tube, 5. Airbag, 6. Substantial leucorrhea, 7. Ventilation pore, 8. Inflation port. DETAILED DESCRIPTION

[0058] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", "vertical", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0059] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0060] The spiral external fixator for limb fractures and its use method of the present invention will be further described in detail below with reference to the accompanying drawings.

[0061] Working principle of the present invention:

[0062] The device mainly consists of a silicone airbag bandage 1, a flexible film pressure sensor 2, a digital display air pump 3, an air filling port 8, and an air guide tube 4.

[0063] 1. Silicone airbag bandage

[0064] (1) Material analysis

[0065] The silicone airbag bandage 1 is made of medical silicone as raw material. Medical silicone material has good tissue compatibility, low irritation to human skin, low toxicity, and weak foreign body sensation. The one-piece molding technology used can effectively avoid air leakage, debonding, etc. The spiral bandage can change with the changes in human body shape and is firmly fixed. See the attached for the specific design. Figure 1 .

[0066] (2) Preparation of silicone airbag bandage

[0067] The silicone mold is based on the prototype and is made using a rapid reproduction process. The production process is shown in Appendix 2.

[0068] Material preparation: mold design and production, medical silicone material, airway tube 4, sealing silicone, connector, cylindrical metal rod, release agent, wire and other material preparation.

[0069] Silicone airbag casting molding:

[0070] ① Pour equal amounts of type A and type B liquid silica gel into the beaker, stir with a glass rod for 3 minutes, and fully

[0071] After mixing, place the beaker containing liquid silica gel in a vacuum degassing machine and degas for 5 minutes.

[0072] ② Pour the degassed liquid silicone into the airbag mold, take out the finished product after curing, and check its air tightness.

[0073] 2. Flexible film pressure sensor

[0074] The flexible film pressure sensor 2 uses the flexible film pressure sensor 2 available on the market as raw material, which has the characteristics of easy manufacturing, low cost, high sensitivity and simple structure. Figure 3 .

[0075] 3. Digital display air pump

[0076] The raw materials used by the digital display air pump 3 are the digital display air pump 3 available on the market, which has the advantages of small size, easy to carry, automatic charging and stopping, etc. The specific design is shown in the attached Figure 4 .

[0077] 4. Inflatable port

[0078] The charging port 8 adopts a stainless steel SUS420 / 40CR valve, which has the characteristics of safety, reliability, low price and stable air pressure.

[0079] 5. Airway

[0080] The air guide tube 4 is made of silicone as raw material, which has the advantages of pressure resistance, wear resistance, and high temperature resistance.

[0081] 6. Device assembly method

[0082] The silicone airbag bandage 1 is made of silicone material. The silicone airbag bandage 1 is in the shape of a thin strip. A certain amount of substantial blank space is left at the edge of the airbag 5 (attached). Figure 5 ), the inner side of the airbag 5 is a trapezoidal structure, the outer side is a semicircular structure, and the middle layer is a uniform solid structure (attached Figure 6 ), there are ventilated gaps between 5 adjacent air cells (attached Figure 7 ), after inflation, each airbag 5 has a range of movement, which can adapt to the displacement caused by swelling of the human body; the silicone airbag bandage 1 leaves an inflation port 8, which is connected to the airway 4; the inflation pump is connected to the flexible film pressure sensor 2 and the airway 4 (attached Figure 8 ); Before the silicone airbag bandage 1 is wrapped around the affected limb, the flexible film pressure sensor 2 is attached to the affected limb, and then the silicone airbag bandage 1 is wrapped around the affected limb. Figure 9 .

[0083] Combined with attachment Figure 1-21 The specific implementation process of the spiral limb fracture external fixator and its use method of the present invention is as follows:

[0084] A spiral external fixator for limb fractures comprises a silicone airbag bandage 1, a flexible film pressure sensor 2, a digital display air pump 3 and an air guide tube 4.

[0085] Silicone airbag bandage 1: Made of silicone, in the shape of thin strips, composed of several airbags 5 connected in sequence. The edges on both sides of the airbag 5 are substantial leucorrhea 6, which can enhance the strength and stability of the bandage and prevent the edges of the airbag 5 from breaking during the wrapping process. The inner side of the airbag 5 is in the shape of a trapezoid, which can better fit the surface of the affected limb and provide uniform pressure distribution; the outer side is a semicircular structure, and the inner and outer sides are substantial structures. This design not only ensures the elasticity of the airbag 5, but also facilitates expansion after inflation. Ventilation holes 7 are provided between adjacent airbags 5, which are conducive to air circulation, improve the breathability of the bandage, and reduce the discomfort of the patient's skin caused by long-term wrapping. The silicone airbag bandage 1 is provided with an inflation port 8, which is connected to the air duct 4 so that it can be connected to the digital display air pump 3 through the air duct 4 to realize the inflation operation.

[0086] Flexible film pressure sensor 2: used to monitor the pressure applied by the silicone airbag bandage 1 on the affected limb in real time, and transmit the pressure data to the digital display inflation pump 3, so that medical staff or patients can adjust the inflation pressure according to actual conditions to ensure that the fixed pressure is within a safe and effective range.

[0087] Digital display air pump 3: connected to the airway tube 4 and the flexible film pressure sensor 2, it can accurately control the inflation amount according to the pressure data fed back by the flexible film pressure sensor 2, so that the silicone airbag bandage 1 reaches the set pressure value, and automatically stops inflation after reaching the set value.

[0088] Airway tube 4: used to connect the inflation port 8 of the silicone airbag bandage 1 and the digital display inflation pump 3 to realize gas delivery.

[0089] How to make silicone airbag bandage:

[0090] Pour equal amounts of type A and type B liquid silica gel into the beaker respectively, and stir with a glass rod for 3 minutes to fully mix the two liquid silica gels.

[0091] The beaker containing the evenly mixed liquid silicone was placed in a vacuum degassing machine for 5 minutes to remove bubbles in the liquid silicone and ensure the quality of the silicone airbag bandage 1.

[0092] Pour the degassed liquid silicone into the airbag mold, take out the finished product after the silicone solidifies, and check its air tightness to ensure that the silicone airbag bandage 1 will not leak during use.

[0093] The inflation port 8 adopts a stainless steel SUS420 / 40CR valve, which has good sealing and corrosion resistance, can ensure that the gas does not leak during the inflation process, and has a long service life.

[0094] The airway tube 4 is made of a silicone tube, which has good flexibility and corrosion resistance, can adapt to the bending and deformation of the silicone airbag bandage 1 during the winding process, and will not hinder the gas transmission.

[0095] A method of using a spiral limb fracture external fixator is as follows:

[0096] Step S1: Sensor attachment and bandage wrapping

[0097] Attach the flexible film pressure sensor 2 evenly to the skin surface near the fracture site of the affected limb, ensuring close contact with the skin to accurately monitor pressure changes. Then, wrap the silicone airbag bandage 1 around the affected limb in a spiral pattern, maintaining the appropriate tightness to avoid being too tight or too loose. Once wrapped, ensure that the flexible film pressure sensor 2 is completely encased within the silicone airbag bandage 1.

[0098] Step S2: Inflation operation

[0099] Plug the power plug of digital air pump 3 into an electrical outlet and turn it on. Set the appropriate pressure on digital air pump 3 based on the patient's specific condition and the doctor's advice. Press the inflation button, and digital air pump 3 will begin inflating the silicone airbag bandage 1 through airway tube 4. During the inflation process, the flexible film pressure sensor 2 monitors the pressure applied by the silicone airbag bandage 1 on the affected limb in real time and transmits this data to digital air pump 3. When the pressure reaches the set value, digital air pump 3 automatically stops inflating.

[0100] Monitoring and adjustment during use:

[0101] During use, medical staff or patients should regularly observe the condition of the affected limb, such as skin color, temperature, sensation, etc. If abnormal conditions such as increased swelling, purple skin, or numbness are found in the affected limb, the pressure of the silicone airbag bandage 1 should be adjusted promptly using the digital inflation pump 3 to ensure the patient's safety.

[0102] Related experimental verification:

[0103] The spiral external fixator for limb fractures proposed in this invention consists of a silicone airbag bandage 1, a flexible film pressure sensor 2, a digital air pump 3, an inflation port 8, and an airway tube 4. The silicone airbag bandage 1 was analyzed and modeled using Abaqus, and its stress and displacement were calculated using finite element analysis to verify the accuracy of the proposed model.

[0104] 1. The present invention uses the femur of a 75kg adult as the research object, and the load is the load borne by a person walking slowly. The force transmitted by the femoral head is F1, the muscle force transmitted by the gluteal muscles is F2, and the muscle force transmitted by the patellotibial band is F3. Figure 10 For the convenience of calculation, a simplified model is obtained as shown in the attached Figure 11 The loads are: Q = 153.3N, M = 48N, N = 760.2N.

[0105] In order to more accurately simulate the mechanical behavior of the fracture state and improve the analysis efficiency, the femoral model was broken in the middle, ignoring the influence of the bone marrow cavity and treating the femoral model as a solid material. The outer side of the femoral model was followed by the soft tissue model and the spiral silicone airbag bandage 1 model. Figure 12-14 These are the wireframe, model, and perspective drawings of the spiral silicone fracture external fixator.

[0106] 2. Interaction between components

[0107] Combined with attachment Figure 15 In finite element analysis, contact conditions are special, discontinuous constraints whose forces vary continuously during the simulation. Constraints exist between contacting surfaces only when they are in contact. These forces act in both normal and tangential directions. The former maintains contact, while the latter can cause sliding and friction. Different contact characteristics are defined by different models, which are crucial for predicting the motion and forces acting on objects.

[0108] A bind constraint is used to secure two surfaces together, ensuring their consistent motion. The master surface is typically a rough or hard surface that serves as a reference, while the slave surface follows the master surface, maintaining contact with it. The slave surface nodes are constrained to the nearest point on the master surface and cannot intrude upon it. To ensure accuracy, the slave surface mesh should be finer. The contact properties for each component are shown in Table 1.

[0109] Table 1: Contact properties of each component

[0110] part 1 (main surface) and 2 (main surface) 2 (main side) and 3 (main side) 4 (main side) and 5 (main side) Contact properties Binding Constraints Small sliding, hard contact, friction coefficient 0.5 Small sliding, hard contact, no friction

[0111] 3. Results and Analysis

[0112] Combined with attachment Figure 16 and attached Figure 17 From the above analysis, we can see that when an adult is stationary or walking slowly, the femur is subjected to superposition of compression and bending loads. It can be clearly observed from the deformed cross-sectional diagram and the deformed cross-sectional diagram after magnification 5 times that a slight separation occurs at one end of the fracture section.

[0113] After a fracture, bone remodeling is influenced by the load environment. Appropriate stress promotes blood circulation, stimulates the growth of new bone cells, accelerates fracture healing, and improves healing quality. Under a stable environment, mechanical stimulation promotes callus formation, achieving indirect fracture healing. Minor displacement of the fracture end under load stimulates callus formation and promotes healing. Therefore, the minor displacement of the fracture site during slow walking after fixation of a femoral fracture with a silicone airbag bandage is reasonable.

[0114] Attachment Figure 18 is the displacement variation diagram along the axial direction, Figure 19 The graph of stress along the axial direction shows that displacement increases axially away from the fixed end, while stress decreases as the bending moment decreases. Neither displacement nor stress changes suddenly. This indicates that the force on the femur is minimally affected by the fracture end, and that Silicone Airbag Bandage 1 can effectively stabilize the fracture.

[0115] Combined with attachment Figure 20 and attached Figure 21 According to the finite element calculation results, the maximum Mises stress of the spiral is 7.255 MPa, and the maximum displacement is 5.243 mm. The maximum Mises stress does not exceed the allowable stress, and the maximum displacement is not too large. Therefore, the silicone airbag bandage 1 is safe in terms of stress and deformation, and is unlikely to be damaged or fail.

[0116] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A spiral external fixator for limb fractures, characterized by: It includes a silicone airbag bandage, a flexible film pressure sensor, a digital display air pump and an airway tube; The silicone airbag bandage is made of silicone and is in the form of a thin strip, consisting of several airbags connected in sequence; the edges of the airbags are solid leucorrhea; the inner side of the airbag is trapezoidal, the outer side is a semicircular structure, and the space between the inner and outer sides is solid; ventilation holes are provided between adjacent airbags; The silicone airbag bandage is provided with an inflation port, the inflation port is connected to the airway tube, and the digital display inflation pump is connected to the airway tube and the flexible film pressure sensor.

2. The spiral external fixator for limb fractures according to claim 1, characterized in that: The manufacturing method of the silicone airbag bandage is as follows: Pour equal amounts of type A and type B liquid silica gel into beakers respectively, stir with a glass rod for 3 minutes, and after thorough mixing, place the beaker containing liquid silica gel in a vacuum degassing machine and degas for 5 minutes; Pour the degassed liquid silicone into the airbag mold, take out the finished product after curing, and check its air tightness.

3. The spiral external fixator for limb fractures according to claim 2, characterized in that: The inflation port adopts a stainless steel SUS420 / 40CR valve.

4. The spiral external fixator for limb fractures according to claim 3, characterized in that: The air guide tube is a silicone tube.

5. A method for using a spiral external fixator for limb fractures, characterized in that: The following steps are involved: S1. Attach the flexible film pressure sensor to the affected limb, then spirally wrap a silicone airbag bandage around the affected limb to enclose the flexible film pressure sensor. S2. Inflate the silicone airbag bandage using the digital air pump and stop when the set value is reached.

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