Shape memory 4D printing orthopedic or fixing device

Abstract

The invention provides a shape memory 4D printing orthopedic or fixing device, and relates to the technical field of medical instruments. The shape memory 4D printing orthopedic or fixing device comprises a support and a feedback system, and the support comprises a shape memory polymer and a reinforcing material; the feedback system comprises a sensing unit, a control unit and a communication unit, and the feedback system is arranged in the support. The stent is softened and can be shaped at will at the temperature above the glass-transition temperature of the shape memory polymer, and the adjustability is good, so that better fitting degree and comfort are ensured; the sensing unit collects environment signals of the support, and the control unit analyzes the environment signals of the support to obtain motion information and pressure information in real time and then controls the shape memory polymer to flexibly change the shape, so that a patient can repeatedly or gradually adjust the fixing state of the support, and the wound is always in the most ideal fixing state.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a shape memory 4D printed orthopedic or fixation device. Background Art

[0002] Currently, fractures and skeletal deformities affect health and reduce quality of life. Treatments for these conditions, including splints, plaster casts, resins, and external fixators, are the primary treatments for these conditions. These fixations are primarily used to stabilize the fracture and promote healing. However, these methods suffer from drawbacks such as poor adjustability, limited stability, and the potential for limb swelling due to poor shaping. Summary of the Invention

[0003] The problem solved by the present invention is how to solve the shortcomings of the fixation method for fractures or skeletal deformities, such as poor adjustability, poor firmness, and limb swelling caused by poor shaping effect.

[0004] In order to solve the above problems, the present invention provides a shape memory 4D printed orthopedic or fixation device.

[0005] The present invention provides a shape memory 4D printed orthosis or fixation device, comprising:

[0006] a stent comprising a shape memory polymer and a reinforcement material; and

[0007] Feedback system, the feedback system includes a sensing unit, a control unit and a communication unit, and the feedback system is placed in the bracket;

[0008] The control unit is respectively connected to the sensing unit and the communication unit. The sensing unit is used to collect the environmental signals of the bracket and transmit them to the control unit. The control unit is used to control the behavior of the shape memory polymer after analyzing the environmental signals of the bracket and thereby adjust the shape of the shape memory 4D printed orthosis or fixation device. The communication unit is used to communicate with external equipment.

[0009] Optionally, the bracket further includes a piezoelectric material, which generates an electrical signal when the bracket is subjected to an external force, and the shape memory polymer deforms under the influence of the electrical signal.

[0010] Optionally, the sensing unit includes a pressure sensor, an accelerometer, an angle sensor and a temperature sensor.

[0011] Optionally, the pressure sensor collects the pressure distribution of the human body on the bracket, the accelerometer collects the dynamic movement behavior of the bracket accompanying the human body, the angle sensor collects the angle deviation between the bracket and the human body's bones, and the temperature sensor collects the temperature transmitted from the human body to the surface of the bracket to form a data set. The sensing unit is used to transmit the data set to the control unit, and the control unit is used to analyze the data set and control the behavior of the shape memory polymer according to the analysis results to adjust the shape of the shape memory 4D printed orthosis or fixation device.

[0012] Optionally, when the shape memory 4D printed orthosis or fixation device is used for the spine and trunk, the control unit is arranged at the position of the bracket corresponding to the human back, and the angle sensor is arranged at the position of the bracket corresponding to the active bone joints of the human body; when the shape memory 4D printed orthosis or fixation device is used for the limbs, the control unit is arranged at the position of the bracket corresponding to the inactive joints of the human body, and the angle sensor is arranged at the position of the bracket corresponding to the active joints of the human body.

[0013] Optionally, the stent includes a pressure release area, a pressure application area and a main body area, and the shape memory polymers of the pressure application area and the main body area are designed using a metamaterial structure.

[0014] Optionally, the glass transition temperature of the shape memory polymer is 65 to 75 degrees, and the pressure application area is provided with a heating unit, which is connected to a control unit. When the pressure exceeds the tolerance range of the human body, the control unit controls the heating unit to heat to above the glass transition temperature of the shape memory polymer, and the shape memory polymer changes from glass to rubber state. The applied load of the pressure application area is adjusted. After the adjustment, the control unit controls the heating unit to stop, and the shape memory polymer changes from rubber state to glass.

[0015] Optionally, the shape memory polymer is one or more of shape memory polyurethane resin, epoxy-based thermoplastic shape memory polymer, epoxy-based thermosetting shape memory polymer, styrene-based shape memory polymer, cyanate-based shape memory polymer, bismaleimide shape memory polymer, polyimide shape memory polymer and polycaprolactone shape memory polymer.

[0016] Optionally, the reinforcing material is one or more of graphite fiber or fiber fabric, carbon fiber or fiber fabric, glass fiber or fiber fabric, poly(p-phenylene terephthalamide) fiber or fiber fabric, boron fiber, silicon carbide fiber, carbon powder, carbon black, carbon nanotubes and nickel powder, with a volume content of 1%-40%.

[0017] Optionally, the piezoelectric material is one or more of nano-barium titanate, sodium potassium niobate and polyvinylidene fluoride, with a volume content of 1%-40%.

[0018] The beneficial effects of a shape memory 4D printed orthosis or fixation device of the present invention are as follows: the shape memory polymer has a shape memory effect based on the transition between the glass state and the rubber state, so that the shape memory 4D printed orthosis or fixation device exhibits adaptability. Above the glass transition temperature of the shape memory polymer, the bracket is softened and can be arbitrarily shaped with good adjustability. The bracket can be personalized according to the patient's specific fracture condition or orthopedic needs to ensure better fit and comfort, and avoid the problem of limb swelling caused by poor shaping effect; reinforcing materials are added to the shape memory polymer to improve mechanical properties and enhance reliability; the sensing unit collects the environmental signal of the bracket, and the control unit analyzes the environmental signal of the bracket to obtain motion information and pressure information, and then controls the shape memory polymer to flexibly change its shape so that the patient can repeatedly or gradually adjust its fixation state, and monitor the patient's bone state and motion state in real time, so that the injury is always in the most ideal fixation state and will not be displaced due to the loose tube type of the orthosis or fixation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural framework diagram of a feedback system for a shape memory 4D printed orthotic or fixation device according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic structural diagram of a support for a shape memory 4D printed orthotic or fixation device according to an embodiment of the present invention;

[0021] Description of reference numerals:

[0022] 1. Pressure release area; 2. Pressure application area; 3. Main area. DETAILED DESCRIPTION

[0023] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the present invention description are only for the purpose of describing specific embodiments and are not intended to limit the present invention;

[0025] As used herein, the term "including" and its variations are open-ended, i.e., "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments." The relevant definitions of other terms will be given in the following description. In the description of this application, unless otherwise specified, "a plurality" means two or more.

[0026] In response to the problems existing in the above-mentioned related technologies, this embodiment provides a shape memory 4D printed correction or fixation device.

[0027] An embodiment of the present invention provides a shape memory 4D printed orthosis or fixation device.

[0028] The present invention provides a shape memory 4D printed orthosis or fixation device, comprising:

[0029] a stent comprising a shape memory polymer and a reinforcement material; and

[0030] like Figure 1 As shown, the feedback system includes a sensing unit, a control unit and a communication unit, and the feedback system is placed in the bracket;

[0031] The control unit is respectively connected to the sensing unit and the communication unit. The sensing unit is used to collect the environmental signals of the bracket and transmit them to the control unit. The control unit is used to control the behavior of the shape memory polymer after analyzing the environmental signals of the bracket and thereby adjust the shape of the shape memory 4D printed orthosis or fixation device. The communication unit is used to communicate with external equipment.

[0032] In this embodiment, the stent can be formed by 4D printing. During the printing process, the printed material is wrapped around the feedback system, so that the feedback system is placed within the stent, thereby preparing a shape memory 4D printed orthosis or fixation device. The shape memory polymer in the stent has a shape memory effect based on the transition between a glassy state and a rubbery state, which makes the shape memory 4D printed orthosis or fixation device exhibit adaptability. Above the glass transition temperature of the shape memory polymer, the orthosis or fixation device is softened and can be arbitrarily shaped, with good adjustability. The fixation device can be personalized according to the patient's specific fracture condition or orthosis needs to ensure better fit and comfort, and avoid the problem of limb swelling that may be caused by poor shaping effect. Reinforcement materials are added to the shape memory polymer to improve mechanical properties and enhance stability. The sensing unit collects environmental signals from the stent, and the control unit analyzes the environmental signals from the stent to obtain motion information and pressure information. It then controls the shape memory polymer to flexibly change shape, allowing the patient to repeatedly or gradually adjust its fixation state. The patient's skeletal state and motion state are monitored in real time, ensuring that the injured area is always in the most ideal fixation state and preventing displacement due to loose tubing of the orthosis or fixation device.

[0033] Specifically, when a patient has scoliosis, ankylosing spondylitis, or spinal deformity, the device can be used for correction and orthodontics; when a patient has a fracture, the device can be used to fix the affected area.

[0034] Specifically, the environmental signals of the stent mainly include the shape signal of the stent, the compression signal of the stent caused by external force, and the movement signal of the stent.

[0035] Specifically, the reinforcing material, also known as the plastic reinforcing agent, refers to a substance added to the shape memory polymer that can be tightly combined with the shape memory polymer and significantly improve the mechanical properties of the product.

[0036] Optionally, the bracket further includes a piezoelectric material, which generates an electrical signal when the bracket is subjected to an external force, and the shape memory polymer deforms under the influence of the electrical signal.

[0037] Specifically, the piezoelectric material generates an electrical signal when the bracket is subjected to external force. The electrical signal is directly related to the pressure value. When the electrical signal exceeds a certain threshold, the shape memory effect of the shape memory polymer is triggered, resulting in deformation behavior.

[0038] Piezoelectric materials are crystalline materials that generate a voltage between their two ends when pressure is applied. Piezoelectric materials exhibit both triboelectric and piezoelectric effects.

[0039] The triboelectric effect refers to the fact that when two different materials come into contact and separate, charge transfer occurs on the surface due to the difference in electron affinity, forming frictional charges. If conductive electrodes are integrated into the structure, the charge imbalance generated during the movement of the material will be converted into induced current or voltage, thereby realizing signal output.

[0040] The piezoelectric effect occurs when a piezoelectric material (such as nano-barium titanate, sodium potassium niobate, or polyvinylidene fluoride) experiences a change in its internal polarization direction when subjected to external mechanical forces (compression, stretching, or bending). This causes charge to accumulate on the material's surface, generating an electrical signal. This effect can be used to capture this charge change by connecting electrodes, enabling precise detection of stress or deformation.

[0041] The principle of directly controlling shape memory polymers with piezoelectric materials relies primarily on the piezoelectric effect of the piezoelectric material and the thermoplastic properties of the shape memory polymer. When an external force acts on the piezoelectric material, a charge separation occurs, creating an electric potential difference. By combining the piezoelectric material with the shape memory polymer, this potential difference can be used to control the shape change of the shape memory polymer.

[0042] Based on the above, in a possible embodiment, the feedback system further includes a power supply unit, which can be a small lithium battery or an energy collection device, embedded in a non-contact part of the shape memory 4D printed orthosis or fixation device (such as the side of the device that does not contact the body).

[0043] Based on the above, in a possible implementation manner, the sensing unit and the control unit are directly electrically connected, the control unit is electrically connected to the communication unit, and the communication unit may use wireless communication.

[0044] You can choose one or more of the following communication methods:

[0045] Bluetooth is suitable for short-range data transmission, low power consumption and high-speed response.

[0046] Wi-Fi is suitable for remote real-time monitoring and can connect to cloud databases for model optimization.

[0047] LoRa or NB-IoT is suitable for low-power, long-distance medical monitoring.

[0048] Optionally, the control unit handles data processing and communication interfaces, using a processor such as the ESP32 (supporting Bluetooth and Wi-Fi) or the STM32 (supporting LoRa). Designed for mobile devices, wearable electronics, and IoT applications, the ESP32 offers industry-leading low-power performance, including fine-resolution clock gating, power-saving modes, and dynamic voltage scaling. The STM32 is a 32-bit microcontroller developed by STMicroelectronics based on the ARM Cortex-M core.

[0049] The communication unit can be embedded in the bracket and work in an integrated manner with the sensing unit and the control unit.

[0050] If the communication unit uses a Bluetooth module (such as BLE5.0), it can be arranged on the side or connection part of the bracket, close to the patient's skin.

[0051] If the communication unit uses a Wi-Fi module, it can be arranged on the control unit and can be powered through the USB interface.

[0052] If the communication unit uses a LoRa module, it is suitable for low-power deployment and is located in a non-critical area of ​​the bracket, such as the outside of the bracket.

[0053] Based on the above, in a possible implementation, the feedback system can also be connected to an external device outside the bracket through a communication unit for communication. The external device can be a mobile device such as a smart phone or a cloud server or a learning module. After the communication is connected, the control unit can transmit the signal to the mobile device or cloud server, so that the patient and the doctor can view the device status, monitor the data and adjust the settings at any time. The adjustment setting signal is transmitted to the control unit through the communication unit for control. It can also respond to environmental changes of the bracket by controlling conditions (such as temperature, etc.), and assist in adjusting the hardness and shape of the device in real time to meet the needs of different recovery stages.

[0054] Optionally, the sensing unit includes a pressure sensor, an accelerometer, an angle sensor and a temperature sensor.

[0055] The sensing data range is as follows:

[0056] The angle sensor is used to measure the angular deviation of the patient's spine. The angle sensor can measure the angle in the range of -30° to 30° with an accuracy of ±0.1°.

[0057] The pressure sensor is used to monitor the correction pressure applied by the bracket to the skin. The pressure sensor can correct the pressure in the range of 0 to 200kPa with an accuracy of ±1kPa.

[0058] The temperature sensor is used to detect the surface temperature of the bracket in contact with the skin. The temperature sensor can detect temperatures in the range of 30 to 40°C with an accuracy of ±0.1°C.

[0059] The accelerometer is used to monitor the patient's movement status and determine whether to dynamically adjust the pressure. The accelerometer can adjust the pressure within a range of ±16g and an accuracy of ±0.01g.

[0060] The pressure adjustment mechanism involves using electrothermal or electromagnetic stimulation to change the shape of the stent, adjusting the magnitude and direction of the corrective force. If the angle sensor in the sensing unit detects that the correction angle is in line with the target, the current force is considered appropriate. If the correction is insufficient or overcorrected, the pressure is adjusted to prevent secondary damage.

[0061] Specifically, the pressure sensor collects the pressure distribution of the human body on the bracket, the accelerometer collects the dynamic movement behavior of the bracket accompanying the human body, the angle sensor collects the angle deviation between the bracket and the human body's bones, and the temperature sensor collects the temperature transmitted from the human body to the surface of the bracket to form a data set. The sensing unit is used to transmit the data set to the control unit, and the control unit is used to analyze the data set and control the behavior of the shape memory polymer according to the analysis results, thereby adjusting the shape of the shape memory 4D printed orthotic or fixation device.

[0062] Optionally, when the shape memory 4D printed orthosis or fixation device is used for the spine and trunk, the control unit is arranged at the position of the bracket corresponding to the human back, and the angle sensor is arranged at the position of the bracket corresponding to the active bone joints of the human body; when the shape memory 4D printed orthosis or fixation device is used for the limbs, the control unit is arranged at the position of the bracket corresponding to the inactive joints of the human body, and the angle sensor is arranged at the position of the bracket corresponding to the active joints of the human body.

[0063] Alternatively, as Figure 2 As shown, the bracket includes a pressure release area 1, a pressure application area 2 and a main body area 3. The shape memory polymer of the pressure application area 2 and the main body area 3 is designed using a metamaterial structure. The metamaterial structure has structural parameters such as metamaterial structure porosity, thickness distribution and support shape.

[0064] Specifically, metamaterial structures are a new type of material that optimizes properties by designing microscopic geometric structures rather than relying on the material itself. Taking advantage of their excellent lightweight and high-strength properties, metamaterials have shown great application potential in orthopedic devices. Through carefully designed metamaterial structures, orthopedic devices can maintain or enhance mechanical properties while significantly reducing weight, improving wearer comfort and reducing movement restrictions. In addition, the customized design capabilities of metamaterials enable them to optimize the stiffness, flexibility and deformation behavior of the device according to the needs of different patients, thereby improving the effectiveness of orthopedic treatment. Combined with additive manufacturing technologies (such as 4D printing), metamaterial structures can achieve high-precision manufacturing of complex geometries, providing revolutionary technical support for the development of next-generation orthopedic devices.

[0065] Pressure release zone 1 is hollowed out to release pressure and is often placed at joints with high human activity, as these areas are more likely to exert greater pressure on the stent. Pressure application zone 2 is also located at joints with high human activity, and a sensing unit is placed in this area to accurately capture the stent's movement behavior. Main body zone 3 is located at inactive joints to secure the stent to the patient and prevent it from falling off. The control unit is often placed in this area.

[0066] Optionally, the glass transition temperature of the shape memory polymer is 65 to 75 degrees, and the pressure application zone 2 is provided with a heating unit, which is connected to the control unit. When the pressure exceeds the tolerance range of the human body, the control unit controls the heating unit to heat to above the glass transition temperature, and the shape memory polymer changes from glass to rubber state. The applied load of the pressure application zone 2 is adjusted. After the adjustment, the control unit controls the heating unit to stop, and the shape memory polymer changes from rubber state to glass.

[0067] Specifically, when the body is subjected to excessive pressure or the sensor unit senses significant pressure, the shape memory properties of the shape memory polymer are triggered. Applying a temperature stimulus to the scoliosis correction device causes it to transition from a glassy state to a rubbery state. Different shape memory polymers have different glass transition temperatures, but those suitable for human use can typically be adjusted to around 70 degrees Celsius through material modification.

[0068] Through material modification, its glass transition temperature can be adjusted to a temperature suitable for human use, which is around 70 degrees.

[0069] By arranging a heating unit (such as a heating wire) in the pressure application area 2, when the pressure exceeds the tolerance range of the human body or makes the patient unable to withstand the heating of the heating unit, the load applied to the pressure application area 2 is adjusted automatically or manually.

[0070] Optionally, the shape memory polymer is one or more of shape memory polyurethane resin, epoxy-based thermoplastic shape memory polymer, epoxy-based thermosetting shape memory polymer, styrene-based shape memory polymer, cyanate-based shape memory polymer, bismaleimide shape memory polymer, polyimide shape memory polymer and polycaprolactone shape memory polymer.

[0071] Specifically, thermoplastic shape memory polymers (SMPs) are a type of smart material with a reversible shape memory effect, usually composed of linear molecular chains or block copolymers. Its shape memory effect depends on the controllable phase change or molecular chain reconstruction of the material at a specific temperature (shape memory conversion temperature). When the material is heated above the conversion temperature, the plasticity increases and it can be deformed into a new shape; after cooling, the shape is fixed, and when heated again it returns to its original shape. Thermoplastic SMPs have the advantages of recyclability, strong processability and multiple shape memory cycles, and are widely used in medical devices, flexible electronics, aerospace, and smart devices. Thermoplastic shape memory polymers can melt when heated to a certain temperature.

[0072] Thermoset Shape Memory Polymers (SMPs) are a class of smart materials composed of a highly cross-linked three-dimensional network structure with irreversible curing characteristics and a significant shape memory effect. Their shape memory behavior depends on the reversible phase change or molecular segment movement of the material at a specific temperature (shape memory transition temperature). When the material is heated above the transition temperature, it can be deformed by external force; after cooling, the shape is fixed, and when heated again, the material returns to its original shape. Due to the cross-linked network structure, thermosetting SMPs exhibit high strength, excellent thermal stability and chemical stability, and are widely used in aerospace, medical implants, structural repair and other fields. Thermosetting shape memory polymers cannot be melted.

[0073] Optionally, the reinforcing material is one or more of graphite fiber or fiber fabric, carbon fiber or fiber fabric, glass fiber or fiber fabric, poly(p-phenylene terephthalamide) fiber or fiber fabric, boron fiber, silicon carbide fiber, carbon powder, carbon black, carbon nanotubes and nickel powder, with a volume content of 1%-40%.

[0074] Optionally, the piezoelectric material is one or more of nano-barium titanate, sodium potassium niobate and polyvinylidene fluoride, with a volume content of 1%-40%.

[0075] Specifically, nano-barium titanate (BaTiO3) can provide the compatibility of high-voltage electrical performance and shape memory function, and can convert external mechanical signals into electrical signals.

[0076] Potassium sodium niobate (KNN) is a lead-free piezoelectric material with high flexibility and biocompatibility, which can be used for dynamic mechanical detection in flexible devices.

[0077] Polyvinylidene fluoride (PVDF) has both piezoelectric and triboelectric properties. Due to its high flexibility and processability, it can be used as a flexible substrate material, while improving the sensitivity and durability of the device.

[0078] Piezoelectric materials can play a role in signal detection. When a patient wears a brace, the applied external force (such as body movement or external pressure) causes the piezoelectric / triboelectric sensor to generate electrical signals; these signals correspond to real-time stress, deformation or contact status information.

[0079] The feedback system can also connect to an external learning module via a communication unit. The learning module receives real-time measurement parameters from the sensor unit in the control unit, analyzes the corrective effect corresponding to the shape of the bracket, and inputs the analysis results into a pre-trained neural network model to predict the optimal corrective force value. The initial prediction model is trained and, based on the initial model, the system gradually adapts to the individual differences of the current patient through transfer learning technology, optimizes the model parameters, and trains and generates a new model. The new model can predict the optimal shape of a shape memory 4D printed orthosis or fixation device that matches the optimal corrective force value. The parameter signal corresponding to the optimal shape can be fed back to the control unit, which can then adjust the shape of the shape memory 4D printed orthosis or fixation device based on the feedback signal.

[0080] Combined with the function of the sensing unit, the patient's bone status can be monitored in real time through the environmental signals of the bracket, and the data can be fed back to the control unit. The control unit then dynamically adjusts the applied pressure to optimize the correction effect, and the control unit transmits the data to the learning module through the communication unit. The learning module continuously optimizes the model and can adapt to new data and requirements. Combined with the function of the sensing unit, the patient's movement status can also be monitored, so that the control unit can provide real-time data analysis and feedback to help medical personnel develop personalized treatment plans, track recovery progress, and prevent complications. Combined with the function of the sensing unit, the fixation status of the shape memory 4D printed orthosis or fixation device can also be monitored in real time, so that the control unit can trigger the shape memory performance of the device in real time, so that the patient can repeatedly or gradually adjust to the optimal fixation state.

[0081] Optionally, shape memory 4D printed orthopedic or fixation devices can utilize the shape memory effect to timely adjust the correction state as the patient's correction recovery degree progresses. The shape memory polymer responds to environmental changes by controlling conditions (such as temperature, humidity, etc.) through a control unit, and adjusts the hardness and shape of the device in real time to meet the needs of different recovery stages.

[0082] Based on the above, in a possible implementation, the application of the learning module in real-time adjustment of the shape of a shape memory 4D printed orthotic or fixation device is mainly reflected in data processing, pattern recognition, and personalized optimization. The following are the specific implementation steps:

[0083] Data collection and feature extraction: The patient's physiological data is collected through the built-in sensing unit of the bracket (such as a pressure sensor or an angle sensor), and the data including pressure distribution and bone angle deviation are input into the control unit; the control unit extracts features, such as the size and distribution of the force-bearing area, the patient's dynamic movement behavior, etc., to form an input data set, and the control unit transmits the data set to the learning module through the communication unit.

[0084] Model training and optimization involves collecting extensive patient data and using machine learning algorithms (such as deep neural networks or support vector machines) to build a predictive model that identifies each patient's force characteristics and correction needs. The model then generates optimized force application and support structure designs based on individual patient characteristics, such as pressure magnitude, distribution, and the metamaterial structure of the shape memory polymer (SMP) used in the metamaterial design.

[0085] The optimized force application scheme and support structure morphology design scheme are transmitted to the control unit, and the control unit adjusts the shape memory 4D printed orthosis or fixation device in real time by triggering the shape memory performance of the device in real time.

[0086] The data flow is roughly as follows: the sensing unit collects patient status data → the control unit processes the data → the communication unit transmits it to the learning module or mobile terminal or cloud → the machine learning model analyzes and optimizes the solution → generates a control signal and feeds it back to the control unit.

[0087] Based on the above, in a possible implementation, the steps of initial model training include:

[0088] Data collection: Historical correction data based on multiple patients can be collected, including angle deviation, applied pressure, skin condition and correction effect.

[0089] Model construction: A multi-layer neural network is used to map the patient's skin condition and applied pressure input to the correction effect output to train the initial prediction model.

[0090] Real-time learning and feedback: The basic bracket records each correction data (such as angle change or pressure value, etc.) through real-time monitoring and updates it to the learning module.

[0091] Through transfer learning, the initial model is gradually adapted to the individual differences of the current patient. Transfer learning is a machine learning method that uses the model developed for task A as a starting point and reuses it in the process of developing a model for task B.

[0092] Model Optimization: Optimize model parameters based on the deviation between the correction target and the actual effect (such as angle deviation and penalty for excessive pressure). New patient data is uploaded to the learning module every day or every few days for centralized training and generation of a new model.

[0093] Results Verification: Compare the pressure values ​​predicted by the model before and after optimization with the actual correction effect to verify the accuracy of the adjustment. Monitor data trends over a long period of time to ensure model stability.

[0094] In a possible embodiment, the trained model is used to customize a shape memory 4D printed orthotic or fixation device for the patient.

[0095] Based on the above, in a possible embodiment, the workflow of a shape memory 4D printed orthotic or fixation device includes:

[0096] Signal detection: When the patient wears the brace, the applied external force (such as body movement or external pressure) causes the sensing unit to collect electrical signals generated by piezoelectricity / triboelectricity; these electrical signals correspond to real-time stress, deformation or contact status information.

[0097] Signal processing and analysis: The detected voltage, current or charge changes are recorded and analyzed by the control unit to extract key features (such as applied load, corrected angle deviation, etc.).

[0098] Combining perception and feedback, shape memory control, the control unit controls the heating or driving behavior of the shape memory polymer material through signal analysis to achieve dynamic adjustment of the bracket shape.

[0099] Intelligent monitoring: signals are transmitted in real time to the learning module or cloud or edge computing device, compared with stored patient data and models, and stent performance is dynamically optimized.

[0100] For example, in smart shape memory 4D printed orthopedic or fixation devices:

[0101] The sensing unit monitors the real-time pressure distribution during patient movement; the sensing unit records dynamic slip and contact events.

[0102] The data is fed into a learning module that analyzes whether the pressure is evenly distributed and dynamically adjusts the shape of the brace to optimize the corrective force.

[0103] Through the sensory feedback of piezoelectric materials, the bracket can also detect the patient's fatigue state after wearing it for a long time, and provide timely reminders or adjustments.

[0104] This combination of perception and feedback systems enables the intelligent application of shape memory polymer materials and sensing technology in medical equipment, greatly improving the adaptability and accuracy of the stent.

[0105] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A shape memory 4D printed orthopedic or fixation device, characterized in that: include: a stent comprising a shape memory polymer and a reinforcing material; as well as A feedback system, the feedback system comprising a sensing unit, a control unit and a communication unit, and the feedback system is placed in the bracket; The control unit is signal-connected to the sensing unit and the communication unit respectively. The sensing unit is used to collect the environmental signal of the bracket and transmit it to the control unit. The control unit is used to control the behavior of the shape memory polymer after analyzing the environmental signal of the bracket and then adjust the shape of the shape memory 4D printed orthosis or fixation device. The communication unit is used to communicate with an external device.

2. The shape memory 4D printed orthosis or fixation device according to claim 1, characterized in that: The support also includes a piezoelectric material, which generates an electrical signal when the support is subjected to an external force, and the shape memory polymer performs deformation behavior under the influence of the electrical signal.

3. The shape memory 4D printed orthosis or fixation device according to claim 1, characterized in that: The sensing unit includes a pressure sensor, an accelerometer, an angle sensor and a temperature sensor.

4. The shape memory 4D printed orthosis or fixation device according to claim 3, characterized in that: The pressure sensor collects the pressure distribution of the human body on the bracket, the accelerometer collects the dynamic movement behavior of the bracket accompanying the human body, the angle sensor collects the angle deviation between the bracket and the human body's bones, and the temperature sensor collects the temperature transmitted from the human body to the surface of the bracket to form a data set. The sensing unit is used to transmit the data set to the control unit, and the control unit is used to analyze the data set and control the behavior of the shape memory polymer according to the analysis results, thereby adjusting the shape of the shape memory 4D printed orthosis or fixation device.

5. The shape memory 4D printed orthosis or fixation device according to claim 3, characterized in that: When the shape memory 4D printed orthosis or fixation device is used for the spine and trunk, the control unit is arranged at the position of the bracket corresponding to the back of the human body, and the angle sensor is arranged at the position of the bracket corresponding to the active bone joints of the human body; when the shape memory 4D printed orthosis or fixation device is used for the limbs, the control unit is arranged at the position of the bracket corresponding to the inactive joints of the human body, and the angle sensor is arranged at the position of the bracket corresponding to the active joints of the human body.

6. The shape memory 4D printed orthosis or fixation device according to claim 1, characterized in that: The bracket comprises a pressure release area, a pressure application area and a main body area, and the shape memory polymer in the pressure application area and the main body area is designed with a metamaterial structure.

7. The shape memory 4D printed orthosis or fixation device according to claim 6, characterized in that: The glass transition temperature of the shape memory polymer is 65 to 75 degrees. The pressure application zone is provided with a heating unit, and the heating unit is connected to the control unit. When the pressure exceeds the tolerance range of the human body, the control unit controls the heating unit to heat to above the glass transition temperature of the shape memory polymer, and the shape memory polymer changes from glass to rubber state. The applied load of the pressure application zone is adjusted. After the adjustment, the control unit controls the heating unit to stop, and the shape memory polymer changes from rubber state to glass.

8. The shape memory 4D printed orthosis or fixation device according to claim 1, characterized in that: The shape memory polymer is one or more of shape memory polyurethane resin, epoxy-based thermoplastic shape memory polymer, epoxy-based thermosetting shape memory polymer, styrene-based shape memory polymer, cyanate-based shape memory polymer, bismaleimide shape memory polymer, polyimide shape memory polymer and polycaprolactone shape memory polymer.

9. The shape memory 4D printed orthosis or fixation device according to claim 1, characterized in that: The reinforcing material is one or more of graphite fiber or fiber fabric, carbon fiber or fiber fabric, glass fiber or fiber fabric, poly(p-phenylene terephthalamide) fiber or fiber fabric, boron fiber, silicon carbide fiber, carbon powder, carbon black, carbon nanotube and nickel powder, and the volume content is 1%-40%.

10. The shape memory 4D printed orthosis or fixation device according to claim 2, characterized in that: The piezoelectric material is one or more of nano barium titanate, sodium potassium niobate and polyvinylidene fluoride, with a volume content of 1%-40%.

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