Adjustable negative Poisson's ratio child ankle-foot orthosis system based on cloth pressure sensing

Abstract

The invention discloses an adjustable negative Poisson's ratio child ankle-foot orthosis system based on cloth pressure sensing, which comprises an orthosis shell and a mobile terminal, a wireless data acquisition module is integrated in the orthosis shell, a negative Poisson's ratio orthosis module is arranged above a bottom plate of the orthosis shell, and the negative Poisson's ratio orthosis module is arranged above the bottom plate of the orthosis shell. A cloth type flexible pressure sensor layer is arranged on the upper surface of the negative poisson ratio shape righting module in an attached mode. The cloth type flexible pressure sensor layer and the negative Poisson's ratio correction module can be detached and replaced. The wireless data acquisition module is wirelessly connected with the mobile terminal to form a closed-loop orthopedic system of real-time pressure detection, pressure analysis, position adjustment of the orthopedic module and re-detection, and dynamic fine adjustment of the foot sole supporting characteristics of the child is achieved. Real-time pressure monitoring and accurate early warning of risks are achieved, real-time and high-resolution collection of plantar pressure is achieved through the cloth type flexible pressure sensor layer, and the mobile terminal timely warns problems of local high pressure, pressure concentration and the like.

Description

Technical Field

[0001] This invention relates to the field of rehabilitation orthotic technology, specifically to an adjustable negative Poisson's ratio ankle-foot orthotic system for children based on fabric pressure sensing. Background Technology

[0002] Ankle-foot deformities in children are a common developmental disorder of the musculoskeletal system, primarily caused by cerebral palsy, spinal cord injury, developmental hip dysplasia, and congenital clubfoot. They manifest as impaired ankle flexion and extension, abnormal foot alignment, leading to gait abnormalities, muscle atrophy, and exacerbation of skeletal deformities, severely impacting children's growth, development, and quality of life. Ankle-foot orthoses (AFOs), as a core non-surgical treatment, help children establish a normal gait and promote normal musculoskeletal development through external support, alignment correction, and movement restriction.

[0003] However, existing pediatric ankle-foot orthoses have several technical shortcomings: First, the orthotic body is mostly made of rigid materials (such as carbon fiber and metal frames) or traditional elastic materials. Rigid materials are uncomfortable to wear and can easily lead to pressure sores and poor blood circulation, while traditional elastic materials lack sufficient support stability and are difficult to achieve precise force line correction. Second, the pressure sensing technology has poor adaptability. Existing orthoses mostly use rigid sensors (such as resistance strain gauges and piezoelectric ceramic sensors) for pressure monitoring. These sensors are hard and lack flexibility, resulting in poor contact with children's delicate skin and easy local pressure. Furthermore, the sensors are scattered and cannot comprehensively collect pressure distribution data from the sole of the foot to the ankle to the lower leg, leading to a lack of accurate basis for evaluating the orthotic effect. Third, the adjustable design is insufficient. Children grow and develop rapidly, and the size and support angle of traditional orthoses are mostly fixed structures, requiring frequent replacements to adapt. The growing demands of children not only increase medical costs, but frequent replacements can also lead to orthodontic interruptions. Furthermore, existing adjustable orthoses are mostly manually adjustable mechanically, lacking dynamic feedback mechanisms and unable to optimize orthodontic parameters in real time based on pressure changes during movement. Fourth, the application of negative Poisson's ratio materials is limited. While these materials possess unique mechanical properties—thickening when stretched and thinning when compressed—and offer excellent impact resistance, support stability, and elastic recovery, their application in pediatric ankle-foot orthoses is mostly limited to single structural forms, failing to integrate with pressure sensing technology and adjustable structures, thus failing to fully leverage the material's advantages. Fifth, the lack of data monitoring and remote intervention capabilities means existing orthoses cannot transmit pressure data to doctors' or parents' terminals in real time, hindering dynamic evaluation and personalized adjustments of orthodontic effects, resulting in orthodontic plans lagging behind children's developmental needs.

[0004] Furthermore, children have higher requirements for wearing comfort. The rigid structure and non-fitting design of traditional orthotics can easily cause resistance, reduce wearing compliance, and thus affect the orthodontic effect. Therefore, developing a pediatric ankle and foot orthotic system that combines flexible pressure monitoring, adjustable negative Poisson's ratio, high comfort, and precise orthodontic functions is key to solving the above-mentioned technical problems. It has important clinical value and social significance for improving the treatment effect of ankle and foot deformities in children, reducing medical costs, and ensuring children's growth and development. Summary of the Invention

[0005] The purpose of this invention is to provide an adjustable negative Poisson's ratio pediatric ankle and foot orthosis system based on fabric pressure sensing, which aims to improve the problem that existing pediatric ankle and foot orthosis systems cannot simultaneously provide pressure monitoring, adjustable negative Poisson's ratio, high comfort, and precise orthotic functions.

[0006] This invention is implemented as follows:

[0007] An adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing includes an orthotic housing and a mobile terminal. The orthotic housing integrates a wireless data acquisition module, and a negative Poisson's ratio orthotic module is positioned above the base plate of the housing. A flexible fabric pressure sensor layer is attached to the upper surface of the negative Poisson's ratio orthotic module. Both the flexible fabric pressure sensor layer and the negative Poisson's ratio orthotic module are detachable and replaceable. The wireless data acquisition module is wirelessly connected to the mobile terminal, forming a closed-loop orthotic system of "real-time pressure detection—pressure analysis—adjustment of orthotic module position—re-detection," enabling dynamic and precise adjustment of the plantar support characteristics of children.

[0008] Preferably, the orthotic housing is made of PP, TPU elastomer or glass fiber reinforced material with a Shore hardness of 85–95A and an anti-slip texture on the surface; the upper surface of the bottom plate of the orthotic housing is divided into a forefoot area, a middle foot area and a hind foot area from front to back, and the bottom plate of the orthotic housing is provided with an array of holes along the forefoot area, the middle foot area and the hind foot area; the two sides of the orthotic housing are symmetrically provided with arc-shaped wrapping side plates, and a battery is integrated into the bottom inner side of the orthotic housing.

[0009] Preferably, the negative Poisson's ratio orthotic module has insertion posts at the positions of the aligned hole array on its bottom surface. The negative Poisson's ratio orthotic module is fabricated using 3D printing technology and is made of TPU, TPEE, or high-resilience polyurethane. The negative Poisson's ratio orthotic module is composed of multiple recessed honeycomb splicing units. The negative Poisson's ratio orthotic module supports horizontal adjustment of ±5-10mm and vertical adjustment of ±5mm, with adjustment increments of 2-4mm. The negative Poisson's ratio orthotic module has three hardness gradients: H1 (Shore hardness 75–80A), H2 (Shore hardness 85–90A), and H3 (Shore hardness 95–100A), to adapt to the support needs of different rehabilitation stages.

[0010] Preferably, the fabric flexible pressure sensor layer adopts a four-layer composite structure from top to bottom: "skin-friendly fabric layer - pressure-sensitive layer - electrode wiring layer - bottom insulation layer". The skin-friendly fabric layer is a cotton-polyester blended fabric, the pressure-sensitive layer is a CNT / MXene coated fabric, the electrode wiring layer is silver fiber wire, and the bottom insulation layer is polyamide fabric. The fabric flexible pressure sensor layer is divided into a forefoot detection area, a midfoot detection area, and a hindfoot detection area. The forefoot and hindfoot detection areas are 3×3 pressure dot arrays, and the midfoot detection area is a 4×4 high-density dot array. The electrode output end of the fabric flexible pressure sensor layer adopts a magnetic interface. The magnetic interface is elliptical with a major axis of 8.5mm × minor axis of 6.2mm and a height of 5.8mm, which facilitates connection and disassembly with the wireless data acquisition module.

[0011] Preferably, the wireless data acquisition module includes a low-power MCU control module, an ADC conversion circuit, a BLE communication module, and a power management module. The MCU control module is used to control the entire wireless data acquisition module. The ADC conversion circuit is used to receive data from the fabric flexible pressure sensor layer and convert the data. The BLE communication module is used to connect the wireless data acquisition module to the mobile terminal. The power management module is used to connect to the battery to manage and allocate the battery's power.

[0012] Preferably, the mobile terminal includes a data receiving and processing module, a visualization module, an indicator calculation module, an adjustment suggestion module, and a data management module. The data receiving and processing module receives pressure data transmitted by the wireless module via BLE, performs filtering processing, and removes noise interference. The visualization module generates a plantar pressure heatmap, which uses a color gradient of blue → green → yellow → red to indicate pressure levels. The indicator calculation module calculates core rehabilitation indicators. The adjustment suggestion module outputs specific adjustment instructions based on abnormal indicator conditions and the distribution of the pore array. The data management module supports local data storage and export to CSV format; generates a monthly rehabilitation report, including indicator change trends, adjustment records, and rehabilitation suggestions; and supports remote data viewing by physicians, who can send personalized adjustment guidance.

[0013] Preferably, the indicator calculation module calculates the core rehabilitation indicators using the following formula:

[0014] S100, Peak Pressure Index (PP): ,in The pressure values ​​for each pressure point are shown; normal range: 200–500 kPa, warning for values ​​exceeding 500 kPa;

[0015] S200, Midfoot Medial Pressure Index (MMF): ;in, This represents the average pressure value at four points on the medial side of the midfoot. The baseline value for normal children is 150 kPa; MMF > 50 kPa indicates foot arch collapse, and MMF < -30 kPa indicates excessive support.

[0016] S300, forefoot-to-hindfoot pressure ratio ( ): ;in, This represents the average pressure in the forefoot area. Average pressure in the hindfoot area; normal range 0.8–1.1, <0.6 indicates insufficient forefoot load, >1.2 indicates forefoot overload;

[0017] S400, left and right pressure symmetry index ( ): ,in The average pressure on the left foot. This represents the average pressure on the right foot. <10% is considered basically symmetrical Asymmetry is considered mild if it is between 10% and 20%. >20% indicates a significant bias.

[0018] Preferably, the device also includes a lower leg shell and a strap. The rear ends of both sides of the corrective shell are provided with adapter plates. The top of the outer side of the adapter plate is provided with a first friction plate. The adapter plate is provided with a stud along the middle of the first friction plate. The stud is provided with a pressure cap. The bottom ends of both sides of the lower leg shell are respectively sleeved on the stud, and the pressure cap is pressed tightly on both sides of the bottom end of the lower leg shell. The strap is provided on the lower leg shell and is used to tie the lower leg shell to the child's leg.

[0019] Preferably, the lower leg housing has adapters at both front ends, adapters with adapter holes in the middle, connecting rods symmetrically arranged on both sides of the bottom of the lower leg housing, connecting rods with connecting holes at their bottom ends, connecting holes fitted onto studs, and a second friction plate provided at the position of the connecting rod aligned with the first friction plate.

[0020] Preferably, the strap is provided with Velcro for adjusting the tightness of the strap, and both ends of the strap are provided with rotating joints, each of which is provided with an adapter post at its end, and the adapter post is rotatably connected to the adapter hole.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. This invention provides real-time pressure monitoring and accurate risk warning: The fabric-type flexible pressure sensor layer enables real-time, high-resolution acquisition of foot pressure, and the mobile terminal provides timely warnings of problems such as local high pressure and pressure concentration, effectively preventing complications such as skin abrasion, redness, swelling, and ulceration.

[0023] 2. This invention features millimeter-level precise adjustment to adapt to dynamic development: The negative Poisson's ratio orthotic module achieves multi-directional adjustment in increments of 2–4 mm through a hole array, matching the slight shift in the center of gravity of the child's foot pressure. It can be dynamically adjusted with foot growth and development, and has strong long-term adaptability.

[0024] 3. This invention allows for home self-adjustment and is simple and convenient to operate: the mobile terminal outputs intuitive adjustment commands, allowing parents to complete operations such as module position adjustment and hardness replacement without professional background, reducing the number of follow-up visits and lowering rehabilitation costs.

[0025] 4. This invention is flexible and comfortable, providing a superior wearing experience: The fabric pressure sensor is only 0.3–1mm thick, soft, breathable, and flexible, without affecting children's walking and foot movement; the negative Poisson's ratio orthopedic module uses flexible materials that expand laterally when compressed, achieving pressure uniformity and improving wearing comfort.

[0026] 5. The closed-loop orthopedic system of this invention can quantify rehabilitation effects: It constructs a closed-loop system of "sensing-analysis-adjustment-feedback", and achieves objective quantitative evaluation of orthopedic effects through four core rehabilitation indicators and stress trend reports, providing physicians with accurate rehabilitation data support.

[0027] 6. This invention is adaptable to multiple scenarios and has a wide range of applications: It is suitable for various children's foot problems such as flexible flat feet, underdeveloped arches, inversion / outversion of the foot, abnormal gait due to cerebral palsy, and uneven foot load caused by neuromuscular diseases. Moreover, both the sensor layer and the negative Poisson's ratio orthopedic module can be disassembled and replaced to adapt to changes in foot size in children of different ages. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of the corrective housing of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of the wireless data acquisition module of the present invention in conjunction with a mobile terminal;

[0031] Figure 4 This is a schematic diagram of the negative Poisson's ratio orthopedic module of the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of the fabric-type flexible pressure sensor layer of the present invention;

[0033] Figure 6 This is a schematic diagram of the layered structure of the fabric-type flexible pressure sensor layer of the present invention;

[0034] Figure 7 This is a schematic diagram of the lower leg shell structure of the present invention;

[0035] Figure 8 This is a schematic diagram of the strap structure of the present invention;

[0036] Figure 9 This is a flowchart illustrating the operation of the system of this invention;

[0037] Figure 10 This is a flowchart of the implementation path of the mobile terminal of the present invention.

[0038] In the diagram: 1. Correction housing; 11. Hole array; 12. Arc-shaped wrapping side plate; 13. Adapter plate; 14. Stud; 15. Pressure cap; 16. First friction plate; 2. Negative Poisson's ratio correction module; 21. Insertion post; 22. Recessed honeycomb splicing unit; 3. Fabric flexible pressure sensor layer; 31. Bottom insulation layer; 32. Electrode wiring layer; 33. Pressure sensitive layer; 34. Skin-friendly fabric layer; 4. Lower leg housing; 41. Adapter; 42. Adapter hole; 43. Connecting rod; 44. Second friction plate; 45. Connecting hole; 5. Strap; 51. Velcro adhesive tape; 52. Rotary joint; 53. Adapter post. Detailed Implementation

[0039] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] The following description, in conjunction with the accompanying drawings and specific embodiments, provides further details:

[0041] Example 1

[0042] like Figure 1 and Figure 3As shown, an adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing includes an orthotic housing 1 and a mobile terminal. The orthotic housing 1 protects the child's foot and facilitates foot correction, while the mobile terminal receives the monitored data. The orthotic housing 1 integrates a wireless data acquisition module to collect pressure data from the child's foot, providing a suitable adjustment plan. A negative Poisson's ratio orthotic module is located on the top plate of the orthotic housing 1, and a flexible fabric pressure sensor layer 3 is attached to the upper surface of the negative Poisson's ratio orthotic module 2. Both the flexible fabric pressure sensor layer 3 and the negative Poisson's ratio orthotic module 2 are detachable and replaceable. The flexible fabric pressure sensor layer 3 detects the pressure state of the child's foot, allowing parents to adjust the negative Poisson's ratio orthotic module 2 according to the pressure state, making the negative Poisson's ratio orthotic module 2 fit the child's foot more closely and facilitating more effective foot correction. The wireless data acquisition module connects wirelessly to the mobile terminal, forming a closed-loop orthopedic system of "real-time pressure detection - pressure analysis - adjustment of orthopedic module position - re-detection", which enables dynamic and precise adjustment of the support characteristics of children's feet.

[0043] like Figure 2 As shown, the orthotic shell 1 is made of PP, TPU elastomer, or glass fiber reinforced material with a Shore hardness of 85–95A and a non-slip textured surface, ensuring stable placement of the orthosis on the child's foot. The base plate of the orthotic shell 1 is divided into forefoot, midfoot, and hindfoot areas from front to back, and each area has a perforation array 11 along its upper edge. This perforation array 11 facilitates the installation of the negative Poisson's ratio orthotic module 2, as well as its assembly and use. Symmetrically arranged arc-shaped wrapping side plates 12 on both sides of the orthotic shell 1 help to wrap around the patient's foot, ensuring stability of the child's foot on the temporal region of the orthotic shell 1. A battery is integrated into the inner bottom of the orthotic shell 1, providing power to the entire orthosis and facilitating its operation.

[0044] like Figure 4 As shown, the bottom surface of the negative Poisson's ratio orthotic module 2 is equipped with insertion posts 21 at the positions aligned with the hole array 11. The insertion posts 21 facilitate insertion into the hole array 11, making the assembly and use of the negative Poisson's ratio orthotic module 2 convenient. The negative Poisson's ratio orthotic module 2 is fabricated using 3D printing technology and is made of TPU, TPEE, or high-resilience polyurethane. The negative Poisson's ratio orthotic module 2 is composed of multiple recessed honeycomb splicing units 22. The negative Poisson's ratio orthotic module supports horizontal adjustment of ±5-10mm and vertical adjustment of ±5mm, with adjustment increments of 2-4mm. The negative Poisson's ratio orthotic module 2 has three hardness gradients: H1 (Shore hardness 75–80A), H2 (Shore hardness 85–90A), and H3 (Shore hardness 95–100A), adapting to the support needs of different rehabilitation stages.

[0045] like Figure 5 and Figure 6 As shown, the fabric-type flexible pressure sensor layer 3 adopts a four-layer composite structure from top to bottom: "skin-friendly fabric layer 34 - pressure-sensitive layer 33 - electrode wiring layer 32 - bottom insulation layer 31". The skin-friendly fabric layer 34 is a cotton-polyester blend fabric with a thickness of 0.1–0.2 mm, which is soft, breathable, and has good sweat absorption. The pressure-sensitive layer 33 is a CNT / MXene coated fabric with a coating thickness of 0.05–0.1 mm. The CNT / MXene coated fabric can be washed to a certain extent, ensuring the normal operation of the fabric-type flexible pressure sensor. The resistance variation range is 1 kΩ–100 kΩ, and the pressure sensitivity is 0.5–1. It exhibits good linearity (R²≥0.98) within the range of 0–1000 kPa. The electrode wiring layer 32 is made of silver fiber wire with an insulating surface treatment, and is fixed to the bottom insulating layer 31 by sewing to form a row and column scanning matrix. The bottom insulating layer 31 is made of polyamide fabric; its thickness is 0.05–0.1 mm, and it is waterproof and sweatproof to prevent electrode short circuits. The fabric flexible pressure sensor layer 3 is divided into a forefoot detection area, a midfoot detection area, and a hindfoot detection area. The forefoot and hindfoot detection areas are 3×3 pressure dot arrays, while the midfoot detection area is a 4×4 high-density dot array. The electrode output end of the fabric flexible pressure sensor layer 3 adopts a magnetic interface. The magnetic interface is elliptical, with a major axis of 8.5mm × minor axis of 6.2mm and a height of 5.8mm, which facilitates connection and disconnection with the wireless data acquisition module. When acquiring data, pressure data is collected using a row and column scanning method. The MCU control module scans the electrodes row by row and column by column to obtain the resistance value of each dot array and converts it into a pressure value. The sampling frequency is 10–50Hz, which can be adjusted according to the usage scenario (50Hz when walking and 10Hz when standing). In actual production, it is necessary to calibrate the flexible fabric pressure sensor. Given the characteristics of the flexible fabric pressure sensor (CNT / MXene coated fabric, 0–1000kPa range, multi-point array distribution), the core calibration objective is to ensure the measurement accuracy, consistency, and environmental adaptability of each pressure point array. The specific calibration method for the flexible fabric pressure sensor is as follows:

[0046] T100, Calibration Equipment and Environmental Conditions

[0047] Core equipment: high-precision pressure calibration stage (range 0–1500kPa, accuracy ±0.1%FS), constant temperature and humidity chamber (temperature 20–35℃, humidity 40–60%RH, simulating a child-friendly environment), data acquisition card (resolution ≥16-bit, compatible with magnetic interface for sensors), and computer (with calibration software installed).

[0048] Auxiliary tools: standard weights (100g–2kg, used to help verify the accuracy of pressure loading), flexible fitting pads (material is the same as the sensor's skin-friendly fabric layer 34, to avoid hard contact that could damage the sensor).

[0049] T200, Calibration Procedure

[0050] T210. Zero-point calibration. Lay the sensor flat and fix it on the calibration table, place it in a constant temperature and humidity chamber and let it stand for 30 minutes to ensure temperature stability. Collect the initial resistance value of each point array when there is no pressure using a data acquisition card, record it as the zero-point reference value, and discard abnormal points arrays with initial deviations exceeding ±5%.

[0051] T220, Gradient pressure loading calibration. In increments of 50 kPa, gradually increase the pressure from 0 kPa to 1000 kPa, holding each pressure level for 5 seconds, and collect the resistance value and corresponding pressure value of each point. Repeat this process 3 times and take the average value to establish a "pressure-resistance" mapping dataset.

[0052] T230, Regional Consistency Calibration. For different detection areas of the foreleg (3×3), midleg (4×4), and hindleg (3×3), gradient loading is applied separately, and the calibration curve of each dot matrix is ​​fitted individually to ensure that the dot matrix error within the region is ≤3%.

[0053] S240. Temperature compensation calibration. Repeat the gradient loading in step 2 at four temperature points: 20℃, 25℃, 30℃, and 35℃. Record the effect of temperature on the resistance value and establish a temperature compensation model (ΔR=k×ΔT+b, where k is the temperature coefficient and b is the intercept).

[0054] T250, Dynamic Calibration. Simulating a child's walking gait, dynamic pressure loading of 10-50Hz is achieved through a calibration platform (matching the sensor sampling frequency) to verify the applicability of the calibration curve under dynamic conditions and correct dynamic response delay errors.

[0055] T300, Data Processing and Verification

[0056] T310. The least squares method is used to fit the "pressure-resistance" curve, and linear fitting is preferred (R²≥0.98). Piecewise fitting is used to optimize the nonlinear section.

[0057] T320. Calculate the calibration error of each dot matrix (the difference between the actual pressure and the measured pressure). Dot matrices with errors exceeding ±2% need to be recalibrated until all dot matrices meet the accuracy requirements.

[0058] The T330 generates a calibration coefficient table (containing the slope, intercept, and temperature compensation coefficient for each dot matrix), which is written to the MCU via a wireless data acquisition module for real-time measurement data calibration.

[0059] like Figure 3 As shown, the wireless data acquisition module includes a low-power MCU control module, an ADC conversion circuit, a BLE communication module, and a power management module. The MCU control module controls the entire wireless data acquisition module. The ADC conversion circuit receives data from the fabric flexible pressure sensor layer 3 and converts the data. The BLE communication module connects the wireless data acquisition module to the mobile terminal. The power management module connects to the battery to manage and allocate battery power. The MCU control module is a Nordic RF52840 or ESP32-C3. The ADC conversion circuit has a resolution of ≥12 bits. The BLE communication module supports the BLE 5.0 / 5.2 protocol, whose core function is to provide the device with efficient, energy-saving, and flexible wireless connectivity. The data transmission rate is no less than 1Mbps, and the communication distance is 5–10m.

[0060] like Figure 3 and Figure 10 As shown, the mobile terminal includes a data receiving and processing module, a visualization module, an indicator calculation module, an adjustment suggestion module, and a data management module. The data receiving and processing module receives pressure data transmitted by the wireless module via BLE, performs filtering processing, and removes noise interference. The visualization module is used to generate a plantar pressure heat map, which uses a color gradient of blue → green → yellow → red to indicate the pressure magnitude. The indicator calculation module is used to calculate core rehabilitation indicators. The adjustment suggestion module is used to output specific adjustment instructions based on abnormal indicator conditions and the distribution of the hole array 11. For example: MMF>50kPa → "Move the midfoot negative Poisson's ratio orthotic module outward by 1 hole (2mm)"; F / H>1.2 → "Move the hindfoot negative Poisson's ratio orthotic module backward by 2 holes (4mm), or replace the H3 hardness module"; SI>20% → "Adjust the tightness of the left side strap 5 and move the medial malleolus module inward by 1 hole." The data management module supports local data storage and export to CSV format; it generates monthly rehabilitation reports, including indicator trends, adjustment records, and rehabilitation suggestions; and it supports remote data viewing by physicians, who can send personalized adjustment guidance. The indicator calculation module uses the following formula to calculate core rehabilitation indicators:

[0061] S100, Peak Pressure Index (PP): ,in The pressure values ​​for each pressure point are shown; normal range: 200–500 kPa, warning for values ​​exceeding 500 kPa;

[0062] S200, Midfoot Medial Pressure Index (MMF): ;in, This represents the average pressure value at four points on the medial side of the midfoot. The baseline value for normal children is 150 kPa; MMF > 50 kPa indicates foot arch collapse, and MMF < -30 kPa indicates excessive support.

[0063] S300, forefoot-to-hindfoot pressure ratio ( ): ;in, This represents the average pressure in the forefoot area. Average pressure in the hindfoot area; normal range 0.8–1.1, <0.6 indicates insufficient forefoot load, >1.2 indicates forefoot overload;

[0064] S400, left and right pressure symmetry index ( ): ,in The average pressure on the left foot. This represents the average pressure on the right foot. <10% is considered basically symmetrical Asymmetry is considered mild if it is between 10% and 20%. >20% indicates a significant bias.

[0065] Mobile terminals include the following functions:

[0066] (1) Use machine learning algorithms to classify and identify stress data, distinguish different movement states such as standing, walking, and running, and automatically adjust the sampling frequency and index judgment threshold;

[0067] (2) Establish a database of children's foot development and dynamically adjust the range of normal indicators according to parameters such as age, gender, and foot length to improve the accuracy of assessment;

[0068] (3) The adjustment suggestion algorithm considers the synergistic effect of module position, hardness, and strap tightness to avoid abnormality of other indicators caused by single adjustment and ensure the optimal adjustment effect.

[0069] The algorithms in the mobile terminal (including core indicator calculation, motion state recognition, adjustment suggestion generation, etc.) are deeply integrated with the system hardware to form a closed loop of "data acquisition-analysis-control-feedback". The specific interaction objects and logic are as follows:

[0070] 1. Data input hardware (the "data source support" for algorithms)

[0071] Fabric-type flexible pressure sensor layer 3: The algorithm obtains the raw pressure data of each dot matrix through this hardware, which serves as the core input for index calculation and motion state recognition. The dot matrix distribution of the sensor (forefoot / midfoot / hindfoot partitions) determines the feature extraction dimension of the algorithm, and the high-density midfoot area (4×4) data provides accurate support for the calculation of the medial midfoot pressure index (MMF).

[0072] Wireless data acquisition module:

[0073] ADC conversion circuit: converts the analog resistance signal of the sensor into a digital signal. The algorithm receives and processes the filtered digital signal. The ADC's resolution of 12 bits or more ensures the accuracy of the algorithm's data input.

[0074] BLE communication module: Enables real-time data transmission. The algorithm must match the transmission rate (≥1Mbps) of the BLE module to ensure that data is not lost under dynamic operating conditions.

[0075] MCU control module: The algorithm sends sampling frequency adjustment instructions (such as 50Hz when walking and 10Hz when standing) to the MCU through the mobile terminal. The MCU controls the sensor's acquisition rhythm according to the instructions.

[0076] 2. Control output hardware (the "execution carrier" of the algorithm)

[0077] The hole array 11 of the correction shell 1: The adjustment suggestions of the algorithm (such as "the middle foot module moves 1 hole outward") need to be generated based on the distribution law of the hole array 11. The spacing of the holes (2-4mm adjustment increment) determines the granularity of the adjustment suggestions.

[0078] Negative Poisson's Ratio Correction Module 2: The algorithm outputs hardness replacement suggestions (such as changing from H2 to H3) based on abnormal core indicators (such as F / H>1.2 indicating forefoot overload). The module's three hardness gradients (H1 / H2 / H3) provide adjustment options for the algorithm.

[0079] Strap 5 adjustment structure: When the algorithm identifies the left and right pressure symmetry index (SI>20%), it outputs a suggestion for adjusting the tightness of strap 5. The Velcro adhesive strip 51 structure of strap 5 supports the accurate execution of the algorithm suggestion.

[0080] 3. Feedback adjustment hardware (support for algorithm effect verification)

[0081] Battery and power management module: The algorithm's motion state recognition results (standing / walking / running) are fed back to the power management module, which dynamically adjusts the power supply strategy (such as increasing power supply when running and reducing power consumption when standing) to ensure a balance between battery life and performance.

[0082] The angle adjustment structure of the lower leg shell 4: The algorithm determines whether the gait is uneven due to abnormal ankle angle by using pressure data, and outputs the angle adjustment suggestions of the lower leg shell 4 and the correction shell 1. The adapter plate 13, stud 14 and other structures support the execution of the adjustment. The adjusted pressure data is fed back to the algorithm to verify the adjustment effect.

[0083] Example 2

[0084] like Figure 1 and Figure 3 As shown, an adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing includes an orthotic housing 1 and a mobile terminal. The orthotic housing 1 protects the child's foot and facilitates foot correction, while the mobile terminal receives the monitored data. The orthotic housing 1 integrates a wireless data acquisition module to collect pressure data from the child's foot, providing a suitable adjustment plan. A negative Poisson's ratio orthotic module is located on the top plate of the orthotic housing 1, and a flexible fabric pressure sensor layer 3 is attached to the upper surface of the negative Poisson's ratio orthotic module 2. Both the flexible fabric pressure sensor layer 3 and the negative Poisson's ratio orthotic module 2 are detachable and replaceable. The flexible fabric pressure sensor layer 3 detects the pressure state of the child's foot, allowing parents to adjust the negative Poisson's ratio orthotic module 2 according to the pressure state, making the negative Poisson's ratio orthotic module 2 fit the child's foot more closely and facilitating more effective foot correction. The wireless data acquisition module connects wirelessly to the mobile terminal, forming a closed-loop orthopedic system of "real-time pressure detection - pressure analysis - adjustment of orthopedic module position - re-detection", which enables dynamic and precise adjustment of the support characteristics of children's feet.

[0085] like Figure 2 As shown, the orthotic shell 1 is made of PP, TPU elastomer, or glass fiber reinforced material with a Shore hardness of 85–95A and a non-slip textured surface, ensuring stable placement of the orthosis on the child's foot. The base plate of the orthotic shell 1 is divided into forefoot, midfoot, and hindfoot areas from front to back, and each area has a perforation array 11 along its upper edge. This perforation array 11 facilitates the installation of the negative Poisson's ratio orthotic module 2, as well as its assembly and use. Symmetrically arranged arc-shaped wrapping side plates 12 on both sides of the orthotic shell 1 help to wrap around the patient's foot, ensuring stability of the child's foot on the temporal region of the orthotic shell 1. A battery is integrated into the inner bottom of the orthotic shell 1, providing power to the entire orthosis and facilitating its operation.

[0086] like Figure 4As shown, the bottom surface of the negative Poisson's ratio orthotic module 2 is equipped with insertion posts 21 at the positions aligned with the hole array 11. The insertion posts 21 facilitate insertion into the hole array 11, making the assembly and use of the negative Poisson's ratio orthotic module 2 convenient. The negative Poisson's ratio orthotic module 2 is fabricated using 3D printing technology and is made of TPU, TPEE, or high-resilience polyurethane. The negative Poisson's ratio orthotic module 2 is composed of multiple recessed honeycomb splicing units 22. The negative Poisson's ratio orthotic module supports horizontal adjustment of ±5-10mm and vertical adjustment of ±5mm, with adjustment increments of 2-4mm. The negative Poisson's ratio orthotic module 2 has three hardness gradients: H1 (Shore hardness 75–80A), H2 (Shore hardness 85–90A), and H3 (Shore hardness 95–100A), adapting to the support needs of different rehabilitation stages.

[0087] like Figure 5 and Figure 6 As shown, the fabric-type flexible pressure sensor layer 3 adopts a four-layer composite structure from top to bottom: "skin-friendly fabric layer 34 - pressure-sensitive layer 33 - electrode wiring layer 32 - bottom insulation layer 31". The skin-friendly fabric layer 34 is a cotton-polyester blend fabric with a thickness of 0.1–0.2 mm, which is soft, breathable, and has good sweat absorption. The pressure-sensitive layer 33 is a CNT / MXene coated fabric with a coating thickness of 0.05–0.1 mm. The CNT / MXene coated fabric can be washed to a certain extent, ensuring the normal operation of the fabric-type flexible pressure sensor. The resistance variation range is 1 kΩ–100 kΩ, and the pressure sensitivity is 0.5–1. It exhibits good linearity (R²≥0.98) within the range of 0–1000 kPa. The electrode wiring layer 32 is made of silver fiber wire with an insulating surface treatment, and is fixed to the bottom insulating layer 31 by sewing to form a row and column scanning matrix. The bottom insulating layer 31 is made of polyamide fabric; its thickness is 0.05–0.1 mm, and it is waterproof and sweatproof to prevent electrode short circuits. The fabric flexible pressure sensor layer 3 is divided into a forefoot detection area, a midfoot detection area, and a hindfoot detection area. The forefoot and hindfoot detection areas are 3×3 pressure dot arrays, while the midfoot detection area is a 4×4 high-density dot array. The electrode output end of the fabric flexible pressure sensor layer 3 adopts a magnetic interface. The magnetic interface is elliptical, with a major axis of 8.5mm × minor axis of 6.2mm and a height of 5.8mm, which facilitates connection and disconnection with the wireless data acquisition module. When acquiring data, pressure data is collected using a row and column scanning method. The MCU control module scans the electrodes row by row and column by column to obtain the resistance value of each dot array and converts it into a pressure value. The sampling frequency is 10–50Hz, which can be adjusted according to the usage scenario (50Hz when walking and 10Hz when standing). In actual production, it is necessary to calibrate the flexible fabric pressure sensor. Given the characteristics of the flexible fabric pressure sensor (CNT / MXene coated fabric, 0–1000kPa range, multi-point array distribution), the core calibration objective is to ensure the measurement accuracy, consistency, and environmental adaptability of each pressure point array. The specific calibration method for the flexible fabric pressure sensor is as follows:

[0088] T100, Calibration Equipment and Environmental Conditions

[0089] Core equipment: high-precision pressure calibration stage (range 0–1500kPa, accuracy ±0.1%FS), constant temperature and humidity chamber (temperature 20–35℃, humidity 40–60%RH, simulating a child-friendly environment), data acquisition card (resolution ≥16-bit, compatible with magnetic interface for sensors), and computer (with calibration software installed).

[0090] Auxiliary tools: standard weights (100g–2kg, used to help verify the accuracy of pressure loading), flexible fitting pads (material is the same as the sensor's skin-friendly fabric layer 34, to avoid hard contact that could damage the sensor).

[0091] T200, Calibration Procedure

[0092] T210. Zero-point calibration. Lay the sensor flat and fix it on the calibration table, place it in a constant temperature and humidity chamber and let it stand for 30 minutes to ensure temperature stability. Collect the initial resistance value of each point array when there is no pressure using a data acquisition card, record it as the zero-point reference value, and discard abnormal points arrays with initial deviations exceeding ±5%.

[0093] T220, Gradient pressure loading calibration. In increments of 50 kPa, gradually increase the pressure from 0 kPa to 1000 kPa, holding each pressure level for 5 seconds, and collect the resistance value and corresponding pressure value of each point. Repeat this process 3 times and take the average value to establish a "pressure-resistance" mapping dataset.

[0094] T230, Regional Consistency Calibration. For different detection areas of the foreleg (3×3), midleg (4×4), and hindleg (3×3), gradient loading is applied separately, and the calibration curve of each dot matrix is ​​fitted individually to ensure that the dot matrix error within the region is ≤3%.

[0095] T240. Temperature compensation calibration. Repeat the gradient loading in step 2 at four temperature points: 20℃, 25℃, 30℃, and 35℃. Record the effect of temperature on the resistance value and establish a temperature compensation model (ΔR=k×ΔT+b, where k is the temperature coefficient and b is the intercept).

[0096] T250, Dynamic Calibration. Simulating a child's walking gait, dynamic pressure loading of 10-50Hz is achieved through a calibration platform (matching the sensor sampling frequency) to verify the applicability of the calibration curve under dynamic conditions and correct dynamic response delay errors.

[0097] T300, Data Processing and Verification

[0098] T310. The least squares method is used to fit the "pressure-resistance" curve, and linear fitting is preferred (R²≥0.98). Piecewise fitting is used to optimize the nonlinear section.

[0099] T320. Calculate the calibration error of each dot matrix (the difference between the actual pressure and the measured pressure). Dot matrices with errors exceeding ±2% need to be recalibrated until all dot matrices meet the accuracy requirements.

[0100] The T330 generates a calibration coefficient table (containing the slope, intercept, and temperature compensation coefficient for each dot matrix), which is written to the MCU via a wireless data acquisition module for real-time measurement data calibration.

[0101] like Figure 3As shown, the wireless data acquisition module includes a low-power MCU control module, an ADC conversion circuit, a BLE communication module, and a power management module. The MCU control module controls the entire wireless data acquisition module. The ADC conversion circuit receives data from the fabric flexible pressure sensor layer 3 and converts the data. The BLE communication module connects the wireless data acquisition module to the mobile terminal. The power management module connects to the battery to manage and allocate battery power. The MCU control module is a Nordic RF52840 or ESP32-C3. The ADC conversion circuit has a resolution of ≥12 bits. The BLE communication module supports the BLE 5.0 / 5.2 protocol, whose core function is to provide the device with efficient, energy-saving, and flexible wireless connectivity. The data transmission rate is no less than 1Mbps, and the communication distance is 5–10m.

[0102] like Figure 3 and Figure 10 As shown, the mobile terminal includes a data receiving and processing module, a visualization module, an indicator calculation module, an adjustment suggestion module, and a data management module. The data receiving and processing module receives pressure data transmitted by the wireless module via BLE, performs filtering processing, and removes noise interference. The visualization module is used to generate a plantar pressure heat map, which uses a color gradient of blue → green → yellow → red to indicate the pressure magnitude. The indicator calculation module is used to calculate core rehabilitation indicators. The adjustment suggestion module is used to output specific adjustment instructions based on abnormal indicator conditions and the distribution of the hole array 11. For example: MMF>50kPa → "Move the midfoot negative Poisson's ratio orthotic module outward by 1 hole (2mm)"; F / H>1.2 → "Move the hindfoot negative Poisson's ratio orthotic module backward by 2 holes (4mm), or replace the H3 hardness module"; SI>20% → "Adjust the tightness of the left side strap 5 and move the medial malleolus module inward by 1 hole." The data management module supports local data storage and export to CSV format; it generates monthly rehabilitation reports, including indicator trends, adjustment records, and rehabilitation suggestions; and it supports remote data viewing by physicians, who can send personalized adjustment guidance. The indicator calculation module uses the following formula to calculate core rehabilitation indicators:

[0103] S100, Peak Pressure Index (PP): ,in The pressure values ​​for each pressure point are shown; normal range: 200–500 kPa, warning for values ​​exceeding 500 kPa;

[0104] S200, Midfoot Medial Pressure Index (MMF): ;in, This represents the average pressure value at four points on the medial side of the midfoot. The baseline value for normal children is 150 kPa; MMF > 50 kPa indicates foot arch collapse, and MMF < -30 kPa indicates excessive support.

[0105] S300, forefoot-to-hindfoot pressure ratio ( ): ;in, This represents the average pressure in the forefoot area. Average pressure in the hindfoot area; normal range 0.8–1.1, <0.6 indicates insufficient forefoot load, >1.2 indicates forefoot overload;

[0106] S400, left and right pressure symmetry index ( ): ,in The average pressure on the left foot. This represents the average pressure on the right foot. <10% is considered basically symmetrical Asymmetry is considered mild if it is between 10% and 20%. >20% indicates a significant bias.

[0107] Mobile terminals include the following functions:

[0108] (1) Use machine learning algorithms to classify and identify stress data, distinguish different movement states such as standing, walking, and running, and automatically adjust the sampling frequency and index judgment threshold;

[0109] (2) Establish a database of children's foot development and dynamically adjust the range of normal indicators according to parameters such as age, gender, and foot length to improve the accuracy of assessment;

[0110] (3) The adjustment suggestion algorithm considers the synergistic effect of module position, hardness, and strap tightness to avoid abnormality of other indicators caused by single adjustment and ensure the optimal adjustment effect.

[0111] The algorithms in the mobile terminal (including core indicator calculation, motion state recognition, adjustment suggestion generation, etc.) are deeply integrated with the system hardware to form a closed loop of "data acquisition-analysis-control-feedback". The specific interaction objects and logic are as follows:

[0112] 1. Data input hardware (the "data source support" for algorithms)

[0113] Fabric-type flexible pressure sensor layer 3: The algorithm obtains the raw pressure data of each dot matrix through this hardware, which serves as the core input for index calculation and motion state recognition. The dot matrix distribution of the sensor (forefoot / midfoot / hindfoot partitions) determines the feature extraction dimension of the algorithm, and the high-density midfoot area (4×4) data provides accurate support for the calculation of the medial midfoot pressure index (MMF).

[0114] Wireless data acquisition module:

[0115] ADC conversion circuit: converts the analog resistance signal of the sensor into a digital signal. The algorithm receives and processes the filtered digital signal. The ADC's resolution of 12 bits or more ensures the accuracy of the algorithm's data input.

[0116] BLE communication module: Enables real-time data transmission. The algorithm must match the transmission rate (≥1Mbps) of the BLE module to ensure that data is not lost under dynamic operating conditions.

[0117] MCU control module: The algorithm sends sampling frequency adjustment instructions (such as 50Hz when walking and 10Hz when standing) to the MCU through the mobile terminal. The MCU controls the sensor's acquisition rhythm according to the instructions.

[0118] 2. Control output hardware (the "execution carrier" of the algorithm)

[0119] The hole array 11 of the correction shell 1: The adjustment suggestions of the algorithm (such as "the middle foot module moves 1 hole outward") need to be generated based on the distribution law of the hole array 11. The spacing of the holes (2-4mm adjustment increment) determines the granularity of the adjustment suggestions.

[0120] Negative Poisson's Ratio Correction Module 2: The algorithm outputs hardness replacement suggestions (such as changing from H2 to H3) based on abnormal core indicators (such as F / H>1.2 indicating forefoot overload). The module's three hardness gradients (H1 / H2 / H3) provide adjustment options for the algorithm.

[0121] Strap 5 adjustment structure: When the algorithm identifies the left and right pressure symmetry index (SI>20%), it outputs a suggestion for adjusting the tightness of strap 5. The Velcro adhesive strip 51 structure of strap 5 supports the accurate execution of the algorithm suggestion.

[0122] 3. Feedback adjustment hardware (support for algorithm effect verification)

[0123] Battery and power management module: The algorithm's motion state recognition results (standing / walking / running) are fed back to the power management module, which dynamically adjusts the power supply strategy (such as increasing power supply when running and reducing power consumption when standing) to ensure a balance between battery life and performance.

[0124] The angle adjustment structure of the lower leg shell 4: The algorithm determines whether the gait is uneven due to abnormal ankle angle by using pressure data, and outputs the angle adjustment suggestions of the lower leg shell 4 and the correction shell 1. The adapter plate 13, stud 14 and other structures support the execution of the adjustment. The adjusted pressure data is fed back to the algorithm to verify the adjustment effect.

[0125] like Figure 1 and Figure 2As shown, the system also includes a lower leg housing 4 and a strap 5. Adapter plates 13 are located at the rear ends of both sides of the corrective housing 1. These adapter plates 13 facilitate rotational connection with the lower leg housing 4, allowing for convenient use of the lower leg housing 4 in conjunction with the corrective housing 1. A first friction plate 16 is located on the top of the outer side of the adapter plate 13. This first friction plate 16 increases the friction between the corrective housing 1 and the lower leg housing 4, facilitating adjustment of the angle between them and improving the overall corrective system's usability. A stud 14 is located along the middle of the first friction plate 16 on the adapter plate 13. A pressure cap 15 is mounted on the stud 14. The lower leg housing 4 is fitted onto the stud 14 at its bottom ends, and the pressure cap 15 is pressed firmly against the bottom ends of the lower leg housing 4. The stud 14 and pressure cap 15 ensure a stable connection between the lower leg housing 4 and the corrective housing 1, facilitating the use of the entire device. The strap 5 is attached to the lower leg housing 4 and used to secure it to the child's leg.

[0126] like Figure 7 and Figure 8 As shown, the lower leg housing 4 has adapters 41 on both front ends, and adapter holes 42 in the middle of the adapters 41. The adapters 41 and adapter holes 42 facilitate the connection between the lower leg housing 4 and the orthopedic housing 1. The lower leg housing 4 has connecting rods 43 symmetrically arranged on both sides of the bottom. The bottom end of the connecting rods 43 has connecting holes 45, which are fitted onto the studs 14. The connecting rods 43 and connecting holes 45 facilitate the stable connection between the lower leg housing 4 and the orthopedic housing 1, and facilitate the stable use of the entire orthopedic system. Furthermore, a second friction plate 44 is provided at the position of the connecting rod 43 aligned with the first friction plate 16. The cooperation between the first friction plate 16 and the second friction plate 44 facilitates the increase of friction between the connecting rod 43 and the adapter plate 13, ensuring sufficient stability after the inclination angle between the calf housing 4 and the orthopedic housing 1 is adjusted. The strap 5 is provided with a Velcro adhesive tape 51 for adjusting the tightness of the strap. Both ends of the strap 5 are provided with rotating joints 52, and each end of the rotating joint 52 is provided with an adapter post 53. The adapter post 53 is rotatably connected to the adapter hole 42, facilitating the fixation and use of the orthopedic system through the strap 5.

[0127] like Figure 9 As shown, the workflow of this orthopedic system is as follows:

[0128] S10. When a child is standing or walking, the fabric flexible pressure sensor layer 3 collects pressure data from various areas of the sole of the foot.

[0129] S20, the wireless data acquisition module transmits pressure data to the mobile terminal in real time via BLE;

[0130] S30: The mobile terminal filters and extracts features from the stress data, and calculates the four core rehabilitation indicators and the stress center trajectory.

[0131] S40. Compare the indicators with baseline data of normal children to determine whether the stress is abnormal;

[0132] S50. If normal, the mobile terminal displays the daily stress trend; if abnormal, it outputs targeted orthopedic adjustment suggestions.

[0133] S60. Parents can adjust the position, rotation angle, or change the hardness of the negative Poisson's ratio orthopedic module 2 according to the adjustment suggestions.

[0134] S70. After adjustment, the system re-collects pressure data and repeats the above process to form a closed-loop optimization until the pressure distribution reaches the ideal state.

[0135] Working principle: When a child stands or walks, the flexible fabric pressure sensor layer 3 (divided into forefoot, midfoot, and hindfoot detection areas, acquiring pressure data from each point array via a row and column scanning matrix) attached to the negative Poisson's ratio orthopedic module first captures pressure signals from different areas of the sole. The CNT / MXene coated fabric of its pressure-sensitive layer 33 changes resistance with pressure, and this change is transmitted to the wireless data acquisition module via the electrode wiring layer 32. The wireless data acquisition module uses a low-power MCU control module to drive an ADC conversion circuit to convert the resistance signal into a digital signal, which is then transmitted in real time to the mobile terminal via a BLE communication module at a rate of no less than 1 Mbps. After receiving the data, the mobile terminal first filters it to remove noise and then extracts features. The system calculates four core rehabilitation indicators: peak pressure index, medial midfoot pressure index, forefoot-to-hindfoot pressure ratio, and left-right pressure symmetry index. It also generates a plantar pressure heatmap, comparing it with baseline data from normal children to determine if the pressure distribution is abnormal. If the data is normal, the mobile terminal only displays the daily pressure trend; if abnormalities are found, it uses the hole array 11 on the bottom plate of the orthotic housing 1 to display the units in the negative Poisson's ratio orthotic module 2 that need adjustment. Parents adjust the units as shown, and the system then collects new pressure data again through the fabric flexible pressure sensor layer 3, repeating the "data acquisition—transmission—analysis—judgment—adjustment" process to form a closed-loop optimization, which can improve the fit between the negative Poisson's ratio orthotic module 2 and the child's foot.

[0136] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing, characterized in that, The device includes a correction housing (1) and a mobile terminal. The correction housing (1) integrates a wireless data acquisition module. A negative Poisson's ratio correction module is provided on the top plate of the correction housing (1). A fabric flexible pressure sensor layer (3) is attached to the upper surface of the negative Poisson's ratio correction module. Both the fabric flexible pressure sensor layer (3) and the negative Poisson's ratio correction module (2) are detachable. The wireless data acquisition module is wirelessly connected to the mobile terminal. The wireless data acquisition module is used to transmit the pressure data detected by the fabric flexible pressure sensor layer (3) to the mobile terminal. The mobile terminal generates an adjustment command based on the received pressure data and sends it back. The adjustment command is used to control the negative Poisson's ratio correction module to adjust its position.

2. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 1, characterized in that, The orthotic housing (1) is made of PP, TPU elastomer or glass fiber reinforced material and has anti-slip texture on the surface; the upper surface of the bottom plate of the orthotic housing (1) is divided into a forefoot area, a middle foot area and a hind foot area from front to back, and the bottom plate of the orthotic housing (1) is provided with a hole array (11) along the forefoot area, the middle foot area and the hind foot area; the two sides of the orthotic housing (1) are symmetrically provided with arc-shaped wrapping side plates (12), and the bottom of the inner side of the orthotic housing (1) is integrated with a battery.

3. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 2, characterized in that, The negative Poisson's ratio orthopedic module (2) has insertion posts (21) at the positions of the alignment hole array (11) on its bottom surface. The negative Poisson's ratio orthopedic module (2) is made of TPU, TPEE or high-resilience polyurethane. The negative Poisson's ratio orthopedic module (2) is spliced ​​from multiple recessed honeycomb splicing units (22). The negative Poisson's ratio orthopedic module supports horizontal ±5-10mm and vertical ±5mm adjustment, with an adjustment increment of 2-4mm. The negative Poisson's ratio orthopedic module (2) has three hardness gradients: H1, H2 and H3. The Shore hardness range of H1 is 75-80A, the Shore hardness range of H2 is 85-90A, and the Shore hardness range of H3 is 95-100A.

4. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 1, characterized in that, The fabric flexible pressure sensor layer (3) is a four-layer composite structure, consisting of a skin-friendly fabric layer (34), a pressure-sensitive layer (33), an electrode wiring layer (32), and a bottom insulating layer (31) from top to bottom. The skin-friendly fabric layer (34) is a cotton-polyester blended fabric, the pressure-sensitive layer (33) is a CNT / MXene coated fabric, the electrode wiring layer (32) is a silver fiber thread, and the bottom insulating layer (31) is a polyamide fabric. The fabric flexible pressure sensor layer (3) is divided into a forefoot detection area, a midfoot detection area, and a hindfoot detection area. The forefoot and hindfoot detection areas are 3×3 pressure dot arrays, and the midfoot detection area is a 4×4 high-density dot array. The electrode output end of the fabric flexible pressure sensor layer (3) adopts a magnetic interface. The magnetic interface is elliptical with a major axis of 8.5mm × minor axis of 6.2mm and a height of 5.8mm, which facilitates connection and disassembly with the wireless data acquisition module.

5. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 2, characterized in that, The wireless data acquisition module includes a low-power MCU control module, an ADC conversion circuit, a BLE communication module, and a power management module. The MCU control module is used to control the entire wireless data acquisition module. The ADC conversion circuit is used to receive data from the fabric flexible pressure sensor layer (3) and convert the data. The BLE communication module is used to connect the wireless data acquisition module to the mobile terminal. The power management module is used to connect to the battery to manage the battery's power.

6. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 1, characterized in that, The mobile terminal includes a data receiving and processing module, a visualization module, an indicator calculation module, an adjustment suggestion module, and a data management module. The data receiving and processing module receives pressure data transmitted by the wireless module via BLE, performs filtering processing, and removes noise interference. The visualization module is used to generate a plantar pressure heat map, and the heat map uses a color gradient of blue → green → yellow → red to indicate the pressure magnitude. The indicator calculation module is used to calculate core rehabilitation indicators. The adjustment suggestion module is used to output specific adjustment instructions based on the abnormality of the indicators and the distribution of the pore array (11). The data management module includes a data storage unit, a monthly report generation unit, and a data export unit. The data storage unit is used for local data storage. The monthly report generation unit is used to generate a monthly rehabilitation report and store it in the data storage unit. The monthly rehabilitation report includes indicator change trends, adjustment records, and rehabilitation suggestions. The data export unit is used to cause the data storage unit to store data according to instructions.

7. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 6, characterized in that, The indicator calculation module uses the following formula to calculate the core rehabilitation indicators: S100, Peak Pressure Index (PP): ,in The pressure values ​​for each pressure point are shown; normal range: 200–500 kPa, warning for values ​​exceeding 500 kPa; S200, Midfoot Medial Compression Index (MMF): ;in, This represents the average pressure value at four points on the medial side of the midfoot. The baseline value for normal children is 150 kPa; MMF > 50 kPa indicates foot arch collapse, and MMF < -30 kPa indicates excessive support. S300, forefoot-to-hindfoot pressure ratio ( ): ;in, This represents the average pressure in the forefoot area. Average pressure in the hindfoot area; normal range 0.8–1.1, <0.6 indicates insufficient forefoot load, >1.2 indicates forefoot overload; S400, left and right pressure symmetry index ( ): ,in The average pressure on the left foot. The average pressure on the right foot; <10% is considered basically symmetrical Asymmetry is considered mild if it is between 10% and 20%. >20% indicates a significant bias.

8. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to any one of claims 1-7, characterized in that, The device also includes a lower leg shell (4) and a strap (5). The corrective shell (1) has an adapter plate (13) at both rear ends. The adapter plate (13) has a first friction plate (16) at the top of its outer side. The adapter plate (13) has a stud (14) along the middle of the first friction plate (16). The stud (14) has a pressure cap (15). The lower leg shell (4) is fitted onto the stud (14) at both bottom ends. The pressure cap (15) is pressed against the lower leg shell (4) at both bottom ends. The strap (5) is placed on the lower leg shell (4) and is used to tie the lower leg shell (4) to the child's leg.

9. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 8, characterized in that, The lower leg housing (4) has an adapter (41) at the front end of both sides, and an adapter hole (42) in the middle of the adapter (41). The lower leg housing (4) has connecting rods (43) symmetrically arranged on both sides of the bottom. The bottom end of the connecting rod (43) has a connecting hole (45). The connecting hole (45) is sleeved on the stud (14), and the connecting rod (43) is provided with a second friction plate (44) aligned with the position of the first friction plate (16).

10. The adjustable negative Poisson's ratio pediatric ankle-foot orthosis system based on fabric pressure sensing according to claim 9, characterized in that, The strap (5) is provided with a Velcro adhesive strip (51) for adjusting the tightness of the strap, and the strap (5) is provided with a rotating joint (52) at both ends. The rotating joint (52) is provided with a connecting post (53) at the end of each connecting post (53), and the connecting post (53) is rotatably connected to the connecting hole (42).

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