Four-connecting-rod knee orthosis applying fabric sensor

Abstract

The invention belongs to the technical field of knee joint orthotics, and discloses a four-bar linkage knee orthotics applying a fabric sensor, which integrates a gait self-adaptive instantaneous center adjustable hinge module through the design of a four-bar linkage mechanism, and shows extremely high flexibility and stability. By applying the mechanical bionics principle, the instantaneous rotation center track of the knee joint of a wearer is comparable with that of the knee joint in a normal physiological state, so that the corrector can be adaptively adjusted according to the gait and walking habit of a user, and a more fitting and natural auxiliary effect is provided. The stretching aid adopts a'safety belt 'locking mechanism and a'quasi-lever' stretching aid mechanism, so that the safety in the using process is remarkably improved, meanwhile, the body burden of a wearer is effectively relieved, and the remarkable stretching aid effect is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of knee joint orthosis, and particularly relates to a four-bar linkage knee orthosis applying a fabric sensor. BACKGROUND

[0002] The base of patients with knee osteoarthritis in China is huge, and epidemiological data shows that the number of patients with knee joint disease has reached more than 100 million, and the middle-aged and elderly population accounts for a large proportion of the total number of patients. Knee osteoarthritis is one of the common chronic degenerative joint diseases in China, which seriously affects the daily life function and quality of life of patients. For the common knee osteoarthritis of elderly patients, pain relief, intra-articular injection, joint cleaning and fixed needle implantation or joint replacement surgery are commonly used in clinical treatment, which requires patients to bear a large surgical risk and recovery burden. In addition, in the postoperative rehabilitation stage, patients have a high degree of dependence on auxiliary support devices, and the functional needs of different patients are quite different, so traditional rehabilitation equipment cannot meet the individualized rehabilitation program.

[0003] Knee joint orthosis is an important part of non-surgical rehabilitation auxiliary devices, and has attracted widespread attention in the field of orthopedic rehabilitation and sports protection. Common knee joint orthosis is mainly used to support the knee joint, limit abnormal movement and reduce joint stress, so as to relieve pain and delay disease progression. However, the knee joint orthosis sold on the market has many technical limitations. On the one hand, the traditional knee joint orthosis mainly uses a single mechanical shaft hinge structure to realize synchronous movement with the knee joint. Although this single-axis structure is simple in process implementation and easy to process, it is difficult to balance stability and flexibility. When the patient performs flexion and extension movement, the single fixed pivot cannot match the real complex kinematic trajectory of the knee joint, resulting in obvious slip and pressure feeling during wearing, thereby reducing the wearing comfort. On the other hand, due to the limitation of the movement degree of freedom of the single-axis structure, its instantaneous flexion center position adjustment ability is insufficient under different flexion angles of the knee joint, and it cannot adapt to the dynamic needs in various motion states.

[0004] In addition, with the popularization of the concept of precision medicine and the development of medical rehabilitation technology, higher requirements are put forward for the functionality of rehabilitation equipment, especially in the aspect of data visualization in the rehabilitation process. The knee joint orthosis on the market mainly focuses on passive support and constraint function, and its design lacks dynamic perception and output of information such as lower limb muscle group load and joint angle change, which cannot provide real-time visualized data in the rehabilitation process for clinicians and patients. This makes the formulation and adjustment of the rehabilitation program lack quantitative basis, which is not conducive to the dynamic evaluation and optimization of the rehabilitation effect.

[0005] In summary, the prior art has the following main problems: the traditional knee joint orthosis device has simple structure but insufficient performance, the single mechanical shaft hinge structure is difficult to simultaneously consider stability and flexibility, resulting in discomfort and mismatched movement state of the wearer during movement; the existing orthosis device cannot dynamically detect and visually output parameters such as joint movement state and lower limb muscle group pressure during rehabilitation, and cannot provide intuitive quantitative basis for rehabilitation scheme adjustment. These technical defects restrict the application and promotion of the knee joint orthosis in precise rehabilitation.

[0006] Based on this, a new knee joint orthosis device and method are needed in the technical scheme design, which can improve the matching of joint movement and wearing stability while ensuring simple structure, and can realize visual detection of key parameters during rehabilitation, providing quantitative evaluation support for patient rehabilitation process. SUMMARY

[0007] In view of the problems existing in the prior art, the application provides a four-bar knee orthosis applying a fabric sensor.

[0008] The application is implemented as follows: a four-bar knee orthosis applying a fabric sensor comprises: The four-bar orthosis and the extension aid mainly include a front rod, an upper rod is arranged at the top of the rear side of the front rod, a rear rod is arranged at one side of the front rod, a lower rod is arranged at the bottom of the rear side of the front rod, and two taper surfaces distributed upward and downward are arranged at the rear end of the front rod. The four-bar orthosis connects the upper rod and the lower rod through a mandrel, and fixes the mandrel by using a screw, so as to limit the translation of the mandrel along the sagittal axis and the rotation of the mandrel around the sagittal axis.

[0009] Further, the relative instantaneous center of the lower rod relative to the upper rod moves upward and downward and forward and backward in the sagittal plane with the flexion and extension of the mechanical knee joint, and the trajectory of the relative instantaneous center is similar to the trajectory of the relative instantaneous center of the movement of the lower leg relative to the upper leg of the human knee joint, so that the instantaneous center position can be adjusted according to different gait cycles. The full-fabric sensor comprises a flexible full-fabric-based lower limb muscle group sensing module and a piezoresistive sensor.

[0010] Further, the flexible electronic fabric used in the flexible full-fabric-based lower limb muscle group sensing module is mainly prepared by an electrode layer and an intermediate conductive layer. The three-layer conductive array configuration is composed of 1+1 rib conductive fabric and MXene modified cotton fabric, which improves the monitoring unit density.

[0011] Further, the piezoresistive sensor utilizes the piezoresistive effect of materials and integrated circuit technology, obtains electrical signal output through resistance change, and is introduced into a background device, and then the pressure size is calculated and displayed on a processor in color depth, so that the flexible electronic fabric has the ability to monitor the dynamic change of pressure.

[0012] In combination with the above technical solutions and the technical problems solved, the technical solutions to be protected by the present application have the following advantages and positive effects: Through the design of the four-bar linkage mechanism, the gait self-adaptive instantaneous center adjustable hinge module is integrated, showing high flexibility and stability.

[0013] By applying the principle of mechanical bionics, the instantaneous rotation center trajectory of the wearer's knee joint is comparable to that of the knee joint in the normal physiological state, so that the corrector can adaptively adjust according to the user's gait and walking habits, thereby providing a more fitted and natural auxiliary effect.

[0014] The extension aid adopts a "safety belt" locking mechanism and a "pseudo-lever" extension mechanism, which significantly improves the safety during use, while effectively reducing the physical burden of the wearer, thereby achieving significant extension effect.

[0015] By adopting the flexible full-fabric lower limb muscle group sensing module, the staggered points on the conductive fabric are more closely ordered, and the monitoring unit density is improved. Under the action of pressure, more contact points are formed, and the conductive path is more easily and quickly formed, so it has the characteristics of high sensitivity and low delay.

[0016] The piezoresistive sensor prepared by utilizing the piezoresistive effect of materials and integrated circuit technology obtains electrical signal output through resistance change and is introduced into a background device, and then the pressure size is calculated and displayed on a processor in color depth, so that the flexible electronic fabric has the ability to monitor the dynamic change of pressure.

[0017] With the help of advanced visual system analysis, precise medical treatment can be realized, and personalized rehabilitation service customization is provided for users to meet the needs of different patients.

[0018] (1) The expected income and commercial value of the technical solutions of the present application after transformation are: Referring to the pricing of main domestic and foreign enterprises in the market, considering the cost of raw materials, labor, existing research and development, and future after-sales service, the product pricing is divided into three grades: low-grade pricing 5000-6000, middle-grade pricing 7000-15000, and high-grade pricing 20000-500000, with an overall gross profit margin of about 60%-80%.

[0019] The product manufacturing cost is greatly reduced compared with the cost of foreign orthosis, and the popularity of the product is improved; compared with the existing domestic orthosis, the stability and flexibility are also creatively considered, the visual tracking of the recovery condition of the user is provided, and the performance is superior. At present, the product has been initially applied to many domestic well-known third-grade hospitals, and has obtained extensive praise of patients and doctors, and has great market prospect.

[0020] (2) The technical scheme of the present application fills the technical gap in the industry at home and abroad: Domestic enterprises such as Beijing Factory, Jingbo Technology and Deao Technology have lower cost than foreign enterprises, and the supply chain is relatively perfect, but the individual adaptability is unstable.

[0021] And the product realizes the technical innovation of four-bar linkage mechanism and stretching aid, ensures the stability and flexibility of the orthosis, fills the gap of poor stability and complicated use steps of domestic orthosis; at the same time, the product greatly reduces the research and development cost, and is helpful to the popularization of the product. (2) The technical scheme of the present application solves the technical problems that people have been eager to solve but have failed to succeed: The present application provides a customized knee joint corrector according to the specific conditions (thigh circumference, calf circumference and knee joint length) of the patient, and through the application of mechanical bionics principle, the instantaneous center trajectory of the knee joint of the wearer is comparable to that of the knee joint in normal physiological state, so that the wearing experience of the user is improved, the orthopedic effect is improved, and the needs of the patient are met.

[0022] The present application utilizes the characteristics of variable instantaneous center of four-bar linkage, and through the design of four-bar linkage mechanism, the instantaneous centers in the support period and swing period are respectively at the upper back and lower front, so as to balance the stability in the support period and the flexibility in the swing period.

[0023] In addition, in order to meet the synchronous tracking of the user's rehabilitation process, the product also adopts a flexible full-textile lower limb muscle group sensing module, which gives the product the characteristics of high sensitivity and low delay; the piezoresistive sensor prepared by applying the piezoresistive effect of the material and integrated circuit technology updates the patient's condition synchronously through the self-contained system.

[0024] (4) The technical scheme of the present application overcomes the technical bias: The existing free-acting hinge type corrector on the market has a rear hinge rotating shaft behind the support, and in the swing period, due to the large distance between the corrector and the instantaneous center of the human knee joint, a significant up-down and front-back movement will be generated, which is not comfortable and may cause skin damage, and is not suitable for patients with sensitive skin, diabetes and the like; after sitting down, the calf cuff will press the patient due to the influence of different shafts, which is very uncomfortable. It is not suitable for patients with poor muscle strength and poor stability.

[0025] And the product application four-bar linkage structure dynamic adjustment instantaneous center position, integrated gait adaptive instantaneous center adjustable hinge module, reduces the possibility of skin damage.

[0026] By applying the principle of mechanical bionics, the trajectory of the instantaneous rotation center of the wearer's knee joint is comparable to that of the normal physiological state of the knee joint, so that the corrector can adaptively adjust according to the user's gait and walking habits, and the feeling of being bound by the orthosis is reduced.

[0027] Meanwhile, the product has provided a variety of knee joint corrector varieties, covering various specifications from basic to high-end customized, not only meeting the differentiated needs of different customers, but also providing personalized treatment plans. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The four-bar linkage knee orthosis structure diagram provided by the embodiment of the application is applied to a fabric sensor.

[0029] Figure 2 The side view of the four-bar linkage knee orthosis provided by the embodiment of the application is applied to a fabric sensor.

[0030] Figure 3 The front view of the four-bar linkage knee orthosis provided by the embodiment of the application is applied to a fabric sensor.

[0031] Figure 4 The monitoring diagram provided by the embodiment of the application is applied to a fabric sensor.

[0032] Figure 5 The swing period mechanical damper structure diagram provided by the embodiment of the application is applied to a fabric sensor.

[0033] In the figure: 1, upper rod; 2, ; 3, upper connecting rod; 4, front rod; 5, rear rod; 6, lower connecting rod; 7, four-bar linkage mechanism; 8, rear desk display analysis unit; 9, lower rod; 10, signal processing and transmission unit; 11, sensing unit; 12, four-bar linkage mechanism; 13, front rod; 14, lower connecting rod; 15, four-bar linkage mechanism; 16, rear rod; 17, upper connecting rod; 18, four-bar linkage mechanism; 19, four-bar linkage mechanism. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the following embodiments are used to further illustrate the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0035] As Figures 1 to 3As shown, the knee joint corrector provided by the present application has a left-right symmetrical structure as a whole, mainly comprising an upper rod 1 fixedly connected with a thigh of a human body, a lower rod 9 fixedly connected with a lower leg of the human body, and a four-bar linkage mechanism arranged between the upper rod 1 and the lower rod 9. The upper rod 1 and the lower rod 9 are reliably fixed with the lateral thighs and lower legs of the user through a binding belt, a pad or a fitting structure, and are used for synchronous movement with the limbs and transmission of correction force.

[0036] The four-bar linkage mechanism is jointly formed by two groups of symmetrical linkage units arranged on the left and right sides, each side comprising an upper linkage rod 3 and 17, a lower linkage rod 6 and 14, a front rod 4 and 13, and a rear rod 5 and 16. The upper linkage rod 3 and 17 are hingedly connected with the upper rod 1 at one end, and the lower linkage rod 6 and 14 are hingedly connected with the lower rod 9 at one end. The front rod 4 and 13 are hingedly connected with the upper linkage rod 3 and 17 and the rear rod 5 and 16 on the corresponding side, respectively. The rear rod 5 and 16 are hingedly connected with the front rod 4 and 13 and the lower linkage rod 6 and 14, respectively, so as to form a closed four-bar linkage movement mechanism.

[0037] A connecting block, a limiting piece and adjusting assemblies 12 to 19 are arranged at the connecting area of the upper linkage rod and the lower linkage rod, which are used for ensuring the synchronous movement of the left and right mechanisms, and can adjust the initial angle, the range of movement or the damping characteristics of the linkage according to the size of the knee joint of the wearer or the needs of the rehabilitation stage. Through the above structure arrangement, the whole corrector has good movement compliance while maintaining high structural strength and wearing stability.

[0038] The core working principle of the knee joint corrector of the present application lies in: the movement characteristics of the instantaneous rotation center of the four-bar linkage mechanism changing with the angle are used to simulate and fit the biomechanical movement trajectory of the real knee joint of the human body.

[0039] As shown, Figure 2 When the user performs the flexion and extension movement of the knee joint, the upper rod 1 moves around the femur of the human body with the thigh, and the lower rod 9 moves around the tibia with the lower leg. Since the human knee joint is not a simple single-axis hinge, the instantaneous center position will continuously migrate during the movement process. The traditional single-axis hinge type protector is difficult to match this characteristic, and is prone to slip, pressure or constraint discomfort during the movement process.

[0040] The present application sets the four-bar linkage mechanism composed of the upper linkage rod 3 and 17, the lower linkage rod 6 and 14, the front rod 4 and 13, and the rear rod 5 and 16, so that a fixed rotation axis is not formed between the upper rod 1 and the lower rod 9, but an equivalent instantaneous center trajectory that changes with the posture is formed. In the initial flexion stage of the knee joint, the geometric relationship of the four-bar linkage mechanism makes the instantaneous center position relatively forward and upward, which is conducive to guiding the lower leg to perform an approximate rolling and sliding compound movement; when the flexion angle increases, the instantaneous center migrates backward and downward, so as to be closer to the movement law of the real knee joint at different flexion stages.

[0041] As shown, Figure 4As shown, the trajectory of the instantaneous center of the four-bar linkage mechanism is a continuously changing curve rather than a fixed point during the entire flexion and extension process, and the trajectory is highly consistent with the kinematic characteristics of the human knee joint. Therefore, during the correction, support or rehabilitation training process, the corrector can allow the knee joint to complete the natural flexion and extension movement while limiting abnormal varus, valgus, hyperextension or deviation, significantly reducing joint shear force and local compression.

[0042] In addition, by reasonably designing the length ratio and hinged position of the front rods 4 and 13 and the rear rods 5 and 16, different correction strategies can be matched, such as enhancing stability within a specific flexion angle range and improving flexibility within other angle ranges, thereby meeting different application requirements such as postoperative rehabilitation, sports protection or functional orthosis.

[0043] Embodiment one: basic structure and four-bar linkage core mechanism As shown in Figures 1 to 4 The knee joint corrector provided by the application comprises an upper rod 1 fixedly connected with a thigh, a lower rod 9 fixedly connected with a lower leg, and a four-bar linkage mechanism arranged between the upper rod 1 and the lower rod 9. The upper rod 1 and the lower rod 9 are fixedly attached to the outside of the thigh and the lower leg of the user through a binding belt or a cladding structure, and are used to move synchronously with the lower limbs of the human body and transmit correction and support force.

[0044] The four-bar linkage mechanism is composed of left and right symmetrical linkage units, each side comprising an upper linkage rod 3 and 17, a lower linkage rod 6 and 14, a front rod 4 and 13, and a rear rod 5 and 16. The front rods 4 and 13 are hinged to the corresponding upper linkage rods 3 and 17 and rear rods 5 and 16, and the rear rods 5 and 16 are hinged to the front rods 4 and 13 and lower linkage rods 6 and 14, thereby forming a closed four-bar linkage movement structure. The instantaneous rotation center of the four-bar linkage mechanism during the flexion and extension of the knee joint is not a fixed point, but continuously changes with the flexion angle, thereby achieving bionics and adjustment of the real movement biomechanical characteristics of the human knee joint from the structure.

[0045] Embodiment two: the instantaneous rotation center of the orthosis changes in a parabolic manner The front upper axis of the corrector at the flexion zero position is taken as the coordination axis, and a plane coordinate system is established at the axis position. The Kinovea motion analysis software is used to analyze the movement process of the knee joint in the range of 0 to 120 degrees of flexion, wherein the instantaneous center position is recorded every 8 degrees in the range of 0 to 80 degrees; in the range of 80 to 120 degrees, the instantaneous center changes slightly, and the instantaneous center position is recorded every 12 degrees for clear expression. As shown in Figure 5 The obtained instantaneous center trajectory presents a J-shaped curve similar to a parabola as a whole, which is highly similar to the instantaneous center change rule of the human knee joint.

[0046] This instantaneous center of gravity trajectory has several advantages: First, by appropriately modifying the instantaneous center of gravity trajectory of the human knee joint, the orthosis has high stability during the support phase and good flexibility during the swing phase; Second, when the knee flexion angle is large, the trajectory is a downward convex arc, which effectively prevents the foot from being lifted too high and affecting the adjustment of the landing posture at the end of the support phase; Third, at the zero-degree flexion position, the instantaneous center of gravity is positioned slightly backward and upward, forming an effect similar to automatic locking, providing strong support without relying on manual operation, which is beneficial for long-term standing or usage scenarios with high stability requirements, while also taking into account the user's psychological feelings and self-esteem needs.

[0047] Example 3: Mechanical damper during oscillation like Figure 5 As shown, two oppositely arranged conical holes are provided on the front rods 4 and 13. The mechanical damper includes a bolt passing through the conical hole and a conical friction plate sleeved on the outside of the bolt. When the nut is tightened, the two conical friction plates press against the conical surfaces of the corresponding conical holes, thereby forming an adjustable planar frictional resistance.

[0048] This mechanical damper primarily functions during the gait swing phase. When a user is walking downhill or accidentally trips, it effectively dampens the knee flexion speed, preventing uncontrolled rapid knee flexion, significantly reducing the risk of falls, and improving walking safety.

[0049] Example 4: Support Phase Instantaneous Center of Motion Adjustment and Extension Limiting Device In the four-bar linkage, the upper links 3 and 17 are connected to the rear links 5 and 16 using an adjustable connection structure. The hinge distance between the upper and rear links can be changed by replacing connecting pins of different lengths or adjusting the position of the mounting holes on the links. When this distance increases, the entire four-bar linkage moves forward, and the instantaneous center of gravity during the support phase moves forward accordingly, making the joint movement more flexible while reducing the maximum extension angle. When this distance decreases, the instantaneous center of gravity moves backward, enhancing overall stability.

[0050] This structure can be adapted to the needs of different stages of postoperative rehabilitation, such as limiting the maximum extension angle in the early stage to protect the joint, training gait through instantaneous heart rate regulation in the middle stage of rehabilitation, or correcting knee hyperextension and flexion contractures, and can achieve continuous orthopedic correction through different day and night settings.

[0051] Examples 5 and 6: Intelligent Monitoring System like Figure 3As shown, the knee joint corrector of the present application further integrates an intelligent monitoring system, which comprises a sensing unit 11, a signal processing and transmission unit 10 and a background display and analysis unit 8. The sensing unit 11 is a full-fabric-based flexible force sensor, which is prepared by integrated weaving forming technology, adopts a three-layer conductive array structure and is directly integrated in the fixing bandage or the covering fabric in contact with the thigh and the lower leg, for real-time and distributed monitoring of local pressure changes.

[0052] The signal processing and transmission unit 10 is electrically connected with the sensing unit 11, for preliminary processing of the collected signals and wireless sending. The background display and analysis unit 8 runs on a mobile terminal or a computer, presents the received data in the form of visual images in real time, intuitively reflects the pressure distribution state through the color depth and area, and provides data support for rehabilitation evaluation and individual adjustment.

[0053] The above is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any modification, equivalent replacement and improvement made by any person skilled in the art within the technical range disclosed by the present application and within the spirit and principles of the present application shall be covered within the protection scope of the present application.

Claims

1. A knee joint correction device, comprising an upper rod for fixed connection with a human thigh, a lower rod for fixed connection with a human calf, and a linkage mechanism arranged between the upper rod and the lower rod, characterized in that the linkage mechanism is a four-bar linkage mechanism, the four-bar linkage mechanism is composed of at least one upper link, a lower link, a front rod and a rear rod on one side, wherein one end of the upper link is hinged to the upper rod, and one end of the lower link is hinged to the lower rod, the front rod is hinged to the upper link and the rear rod respectively, and the rear rod is hinged to the front rod and the lower link respectively, the four-bar linkage mechanism forms an equivalent instantaneous rotation center continuously changing with the flexion angle during the relative rotation of the upper rod and the lower rod, the equivalent instantaneous rotation center migrates along a continuous trajectory during flexion and extension, so that the upper rod and the lower rod do not form a fixed rotation shaft relationship.

2. The knee joint correction device according to claim 1, characterized in that the four-bar linkage mechanism is two groups of linkage units arranged symmetrically left and right, the two groups of linkage units are consistent in structure size and hinged topology, and are used to ensure the synchronous movement of the upper rod and the lower rod in the left and right directions.

3. The knee joint correction device according to claim 1, characterized in that in the four-bar linkage mechanism, the upper link and the front rod preferentially participate in the movement at the initial stage of knee joint flexion and extension, so that the equivalent instantaneous rotation center is located on the side close to the upper rod, and the relative sliding trend between the upper rod and the lower rod at the initial stage of flexion and extension is reduced.

4. A knee joint correction device, comprising an upper rod, a lower rod, a four-bar linkage mechanism and an adjusting assembly, characterized in that the adjusting assembly is arranged in the linkage connection area of the four-bar linkage mechanism, the adjusting assembly is used to change the initial geometric state of the four-bar linkage mechanism, the adjusting assembly adjusts the movement participation proportion of the four-bar linkage mechanism in different flexion angle intervals in an overall manner, and the adjusting effect of the adjusting assembly on the four-bar linkage mechanism shows an overall influence on the migration trajectory of the equivalent instantaneous rotation center.

5. The knee joint correction device according to claim 4, characterized in that the adjusting assembly is used to adjust the stress distribution relationship of the four-bar linkage mechanism at the initial stage of flexion and extension and at the later stage of flexion, so as to change the dominant action sequence of the upper link, the lower link, the front rod and the rear rod at different stages.

6. The knee joint correction device according to claim 4, characterized in that the adjusting assembly is used to limit the migration of the equivalent instantaneous rotation center within a preset spatial range, so as to allow the upper rod and the lower rod to complete natural flexion and extension movement while limiting abnormal movement direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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