Multi-mode and multi-posture knee joint rehabilitation equipment and control method thereof

Abstract

The invention discloses multi-mode and multi-posture knee joint rehabilitation equipment and a control method thereof. The knee joint rehabilitation equipment is composed of a thigh fixing part, a shank fixing part, an inner side joint assembly, an outer side joint assembly, a double-lasso transmission assembly, a motor, an electromyographic signal measuring unit, a first processing module, an inertia measuring unit, a second processing module, a control module and the like. The knee joint rehabilitation equipment is wearable rehabilitation equipment, a user can carry out rehabilitation training under four kinds of rehabilitation such as prone position rehabilitation, sitting position rehabilitation, standing rehabilitation and walking rehabilitation, more personalized training is provided for the user, and the knee joint rehabilitation equipment has a wider application scene; in addition, a passive mode and an active and passive combined mode are provided, the passive mode helps the rehabilitation user to recover the joint function through passive movement, the active and passive combined mode assists the user in autonomous movement to conduct rehabilitation training through external force, the two modes are suitable for different rehabilitation stages of the user, and the more efficient rehabilitation effect can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of rehabilitation equipment, and in particular to a multi-mode and multi-posture knee joint rehabilitation equipment and a control method thereof. Background Art

[0002] CPM (Continuous Passive Motion) is a device used for knee rehabilitation that relies on continuous passive motion to help rehabilitation users restore joint function. CPM simulates normal joint movement by constantly moving the user's knee joint within a set range. This continuous passive motion helps reduce joint stiffness after surgery or injury and promotes the repair and metabolism of cartilage in the joint. CPM can accurately control the range and speed of joint movement and adjust it according to the rehabilitation stage and the user's individual situation to ensure that rehabilitation exercises are performed within a safe range while avoiding additional stress or damage to the joints. In addition, CPM can promote blood circulation and the flow of lubricating fluid in the joints when performing passive movements. This helps reduce joint swelling and increase the supply of nutrients, which is beneficial to the progress and speed of rehabilitation.

[0003] CPM is often used for post-operative recovery of the knee joint, rehabilitation after trauma or injury, and disease or degenerative changes. However, CPM uses passive movement, rather than autonomous rehabilitation exercises to enhance muscle strength and function, which may cause users to rely too much on the device, thus affecting the rehabilitation effect. Moreover, CPM usually requires users to lie down and be operated by professionals, so its application scenarios and scope are also limited.

[0004] In summary, although the knee CPM machine has its unique advantages and application scenarios in the rehabilitation process, it also has some potential defects and limitations. Medical professionals need to consider the user's individual situation and rehabilitation goals when selecting and recommending it. Summary of the invention

[0005] In order to enhance the rehabilitation effect of a knee joint rehabilitation device and reduce its defects and limitations, the present invention provides a multi-mode and multi-posture knee joint rehabilitation device and a control method thereof.

[0006] The technical solution adopted by the present invention is as follows: a multi-mode and multi-posture knee joint rehabilitation device, characterized in that it includes: a thigh fixing part and a calf fixing part, respectively used to fix the thigh part and the calf part of the leg that needs rehabilitation; an inner joint component, rotatably connected to the inner side of the thigh fixing part and the calf fixing part; an outer joint component, having a rotating shaft and a first rotating plate and a second rotating plate hinged to each other, respectively fixed to the thigh fixing part and the calf fixing part; a double lasso transmission component, used to drive the second rotating plate to rotate equivalent to the first rotating plate; a motor, fixed to the waist or back, and connected to the double lasso transmission component; an electromyographic signal measuring unit A first processing module is used to detect the electrical activity of the leg muscles and collect electromyographic data; a first processing module is used to identify the muscle contraction and movement intention of the leg according to the electromyographic data; an inertial measurement unit is used to detect the acceleration and angular velocity of the knee joint or related parts on three axes; a second processing module is used to perform time domain-frequency domain data conversion on the acceleration values ​​of the knee joint or related parts in multiple directions, and compare the amplitude of the frequency domain data with a reference value, and determine the movement intention of the leg according to the comparison result; a control module is used to control the rotation action of the motor based on a predetermined input signal and the output signal of the first processing module or the second processing module.

[0007] Preferably, the thigh fixing member and the calf fixing member are arched plates made of lightweight, hard materials, respectively covering the front sides of the thigh and calf, and are fixed with straps.

[0008] Preferably, the medial joint assembly includes a third rotating plate, a connecting plate and a fourth rotating plate connected in sequence, and the adjacent ends of the third rotating plate and the fourth rotating plate have mutually meshing transmission teeth; the upper end of the third rotating plate and the lower end of the fourth rotating plate are fixed to the thigh fixing member and the calf fixing member, respectively.

[0009] Preferably, the installation positions of the first rotating plate, the third rotating plate and the thigh fixing member are adjustable, and the installation positions of the second rotating plate, the fourth rotating plate and the calf fixing member are adjustable.

[0010] Preferably, the double lasso transmission assembly includes: an active rotating disk, rotating with the output shaft of the motor; a driven rotating disk, fixedly mounted on the second rotating plate; a bearing, supported between the driven rotating disk and the rotating shaft; and a double lasso, transmission-connected between the active rotating disk and the driven rotating disk.

[0011] Preferably, the electromyographic signal measurement unit is used for the electrical activities of the quadriceps femoris and the gastrocnemius; the inertial measurement unit includes an accelerometer and a gyroscope, which are installed at the part of the calf near the ankle.

[0012] Preferably, the knee joint rehabilitation equipment has four usage postures: lying, sitting, standing and walking.

[0013] The second set of technical solutions adopted by the present invention is as follows: a control method for a multi-mode and multi-posture knee joint rehabilitation device, having a passive mode for controlling the rotation action of the motor based on a predetermined output signal, and an active and passive combined mode for controlling the rotation action of the motor based on the output signal of the first processing module or the second processing module.

[0014] Preferably, the steps of the active-passive combination mode are as follows: Step 1. The user puts on the rehabilitation equipment and selects the active and passive combination mode; Step 2. The user autonomously controls the leg movements, the electromyographic signal measurement unit detects the electrical activity of the leg muscles, collects electromyographic data, and the inertial measurement unit detects the acceleration and angular velocity of the knee joint or related parts on three axes; Step 3. According to the order of amplitude, frequency, stability, waveform shape, and consistency with the data of triaxial acceleration and angular velocity, determine whether the electromyography data is normal. If the electromyography data is determined to be within the normal range, proceed to step 4. If the electromyography data is determined to be abnormal, proceed to step 5. Step 4. If the EMG data is normal, the first processing module identifies the muscle contraction and movement intention of the leg according to the EMG data, and controls the rotation of the motor based on the output signal of the first processing module, and uses the thigh fixing member and the calf fixing member to drive the thigh and calf to perform rehabilitation movements; Step 5. If the EMG data is abnormal, the second processing module performs time domain-frequency domain data conversion on the acceleration values ​​of the knee joint or related parts in multiple directions, and compares the amplitude of the frequency domain data with the reference value, and determines the leg movement intention based on the comparison result, and controls the rotation movement of the motor based on the output signal of the second processing module, and utilizes the thigh fastener and the calf fastener to drive the thigh and calf to perform rehabilitation movements.

[0015] Preferably, step 1 also includes static calibration and dynamic calibration of the inertial measurement unit; The steps for static calibration are: Step 1.1. Place the IMU on a stationary flat surface, ensuring there is no external motion or vibration. Step 1.2. Record the output data of the accelerometer and gyroscope of the inertial measurement unit when it is stationary, collecting data for tens of seconds to several minutes; Step 1.3. For the data on each axis, calculate its average value as the zero bias compensation parameter for static calibration; Step 1.4. Apply the calculated zero bias compensation parameters to the real-time data to reduce the static error; The dynamic calibration steps are: Step 1.5. After the user puts on the rehabilitation device, he / she first selects a certain posture of lying, sitting, standing or walking, and then selects the preset dynamic calibration parameters in the passive mode to control the rotation of the motor, uses the thigh fixing part and the calf fixing part to drive the thigh and calf movements, and records the output data of the inertial measurement unit; Step 1.6. Use the real data of the control motion to compare with the output data recorded by the inertial measurement unit to identify and correct dynamic errors; Step 1.7. After completing the calibration, perform a secondary dynamic calibration verification to ensure that the IMU is performing as expected.

[0016] The present invention has the following beneficial effects: 1. Multi-posture: It is a wearable rehabilitation device that allows users to perform rehabilitation training in four different positions: lying, sitting, standing and walking. It provides users with more personalized training and has a wider range of application scenarios. 2. Multi-mode: It has a passive mode and an active-passive combined mode. The passive mode helps rehabilitation users restore joint function through passive movement, and the active-passive combined mode uses external force to assist the user's autonomous movements for rehabilitation training. Both modes are suitable for different rehabilitation stages of users and can achieve more efficient rehabilitation effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of an embodiment of the present invention.

[0018] Figure 2 Schematic diagram of the medial joint assembly in an embodiment of the present invention.

[0019] Figure 3 Schematic diagram of the outer joint assembly in an embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of the assembly of the double lasso transmission assembly and the outer joint assembly in an embodiment of the present invention.

[0021] Figure 5 A system block diagram of an embodiment of the present invention.

[0022] Figure 6 Flow chart of the electromyography data judgment process in an embodiment of the present invention.

[0023] Figure 7 4 is a flow chart of static calibration of an inertial measurement unit in an embodiment of the present invention.

[0024] Figure 8 The figure is a flow chart of dynamic calibration of an inertial measurement unit in an embodiment of the present invention.

[0025] In the figure: Thigh fixing part 1; Lower leg fixing piece 2; The inner joint assembly 3, the third rotating plate 301, the fourth rotating plate 303, the connecting plate 302; Outer joint assembly 4, rotating shaft 401, first rotating plate 402, second rotating plate 403, end cover 404; Double lasso transmission assembly 5, active rotating disk 501, driven rotating disk 502, bearing 503, double lasso 504; Motor 6; Inertial measurement unit 9; Myoelectric signal measuring unit 7; A first processing module 8; Inertial measurement unit 9; A second processing module 10; Control module 11. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the embodiments and drawings.

[0027] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0030] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0031] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] In the embodiment, Figures 1 to 4As shown, a multi-mode and multi-posture knee joint rehabilitation device comprises: a thigh fixing part 1 and a calf fixing part 2, respectively used to fix the thigh part and the calf part of the leg that needs rehabilitation; an inner joint component 3, rotatably connected to the inner side of the thigh fixing part 1 and the calf fixing part 2; an outer joint component 4, having a rotating shaft 401 and a first rotating plate 402 and a second rotating plate 403 hinged to each other, respectively fixed to the thigh fixing part 1 and the calf fixing part 2; a double lasso transmission component 5, used to drive the second rotating plate 403 to rotate equivalent to the first rotating plate 402; a motor 6, fixed to the waist or the back, and connected to the double lasso transmission component 5; an electromyographic signal measuring unit Element 7 is used to detect the electrical activity of leg muscles and collect electromyographic data; the first processing module 8 is used to identify the muscle contraction and movement intention of the leg according to the electromyographic data; the inertial measurement unit 9 is used to detect the acceleration and angular velocity of the knee joint or related parts on three axes; the second processing module 10 is used to convert the acceleration values ​​of the knee joint or related parts in multiple directions from time domain to frequency domain data, and compare the amplitude of the frequency domain data with the reference value, and determine the movement intention of the leg according to the comparison result; the control module 11 is used to control the rotation of the motor 6 based on the predetermined input signal and the output signal of the first processing module 8 or the second processing module 10. The thigh fixing member 1 and the calf fixing member 2 are wearable structures, which are worn from the positive direction of the thigh and calf respectively, and then fixed with a strap; the double lasso transmission component 5 is a long-distance flexible transmission, which can realize the effective separation of the motor 6 and the outer joint component 4, and at the same time can reduce the interference with the user's autonomous movement to a certain extent; the motor 6 is fixed to the waist or abdomen through a strap; the mass and rotational inertia of the knee joint and the entire leg are reduced, which reduces the burden on the user. This embodiment is a lightweight wearable rehabilitation device. Users can perform rehabilitation training in four rehabilitation positions, namely, lying, sitting, standing and walking. Therefore, it can provide users with more personalized training and has a wider range of application scenarios.

[0034] In the embodiment, Figures 1 to 3 As shown, the thigh fixing member 1 and the calf fixing member 2 are arched plates made of light and hard materials, and specifically, materials such as ABS plastic, polycarbonate, polyethylene, nylon and polypropylene can be used. These materials have sufficient strength, rigidity and durability, and are light enough to support the stability and safety required by the rehabilitation equipment during use. In addition, the arched plate also has a hollow structure to further reduce the weight of the thigh fixing member 1 and the calf fixing member 2 to provide comfort for the user.

[0035] In the embodiment, Figure 2As shown, the medial joint assembly 3 includes a third rotating plate 301, a fourth rotating plate 303 and a connecting plate 302 connected in sequence, and the adjacent ends of the third rotating plate 301 and the fourth rotating plate 303 have mutually meshing transmission teeth; the upper end of the third rotating plate 301 and the lower end of the fourth rotating plate 303 are respectively fixed to the thigh fixing member 1 and the calf fixing member 2. The meshing transmission teeth of the third rotating plate 301 and the fourth rotating plate 303, and their fixation to the thigh fixing member 1 and the calf fixing member 2, help to accurately control the movement trajectory and angle of the knee joint, which is particularly important for users who need to control specific movement parameters during the rehabilitation process, and can ensure the accuracy of the movement and the predictability of the effect. Through precise control and stable structural support, the rehabilitation equipment can more effectively help restore the function and range of motion of the knee joint and promote the user's rehabilitation process.

[0036] In the embodiment, Figure 3 As shown, the installation positions of the first rotating plate 402, the third rotating plate 301 and the thigh fixing member 1 are adjustable, and the installation positions of the second rotating plate 403, the fourth rotating plate 303 and the calf fixing member 2 are adjustable. The first rotating plate 402, the second rotating plate 403, the third rotating plate 301 and the fourth rotating plate 303 are assembled in the form of a long hole with a slide groove, and their installation positions are adjustable, allowing adjustment according to the individual situation and rehabilitation stage of the user. This adjustability enables the rehabilitation equipment to adapt to users of different body shapes and athletic abilities, providing conditions for providing a more personalized rehabilitation plan.

[0037] In the embodiment, Figure 4As shown, the double lasso transmission assembly 5 includes: an active rotating disk 501, which rotates with the output shaft of the motor 6; a driven rotating disk 502, which is fixedly mounted on the second rotating plate 403; a bearing 503, which is supported between the driven rotating disk 502 and the rotating shaft 401; and a double lasso 504, which is connected between the active rotating disk 501 and the driven rotating disk 502. The active rotating disk 501 is driven to rotate by the output shaft of the motor 6, so that the device can provide active motion assistance or resistance, which can be adjusted according to the rehabilitation stage and treatment goals. The electric drive design can provide users with precise motion control, which helps to rebuild knee joint function and enhance muscle strength. The driven rotating disk 502 of the double lasso transmission assembly 5 is supported on the rotating shaft 401 by the bearing 503, which ensures the stability and reliability of the transmission system, makes the transmission process more stable and effective, reduces friction loss during movement, and improves the service life of the device. The double lasso transmission assembly 5 enables the active rotating disk 501 and the driven rotating disk 502 to be connected by a double lasso 504, which can provide smoother force transmission and control, while reducing looseness and errors in the transmission process, thereby enhancing the movement accuracy and stability of the device. The combination of electric drive and double lasso transmission can better adapt to wearable devices and provide more treatment modes and posture options for rehabilitation equipment. Through precise force control and transmission adjustment, rehabilitation professionals can formulate personalized rehabilitation plans based on the specific conditions of the user to improve the treatment effect and rehabilitation speed.

[0038] In the embodiment, the electromyographic signal measuring unit 7 is used for the electrical activity of the quadriceps and gastrocnemius. The quadriceps is the main muscle group on the front side of the knee joint, and is composed of four independent muscles: the rectus femoris, vastus medialis, vastus lateralis and vastus musculus. The quadriceps is very important for the extension of the knee joint, and is also involved in a certain degree of joint stability; the hamstring is a small muscle located on the back side of the knee joint, which mainly unlocks the joint when the knee is bent, and provides stability and control during the bending of the joint. The electromyographic signal measuring unit 7 captures the contraction and electrical activity of the quadriceps and hamstrings in real time, and the first processing module 8 can identify the muscle contraction and movement intention of the leg based on this, and then control the rotation of the motor 6 to provide auxiliary power when the user's knee joint is self-help.

[0039] In the embodiment, Figure 1 As shown, the inertial measurement unit 9 includes an accelerometer and a gyroscope, which are installed at the part of the calf near the ankle by means of a strap. Generally speaking, the range of motion of the calf near the ankle is greater than that of the knee joint. Therefore, by indirectly measuring the movement trend of the knee joint through the sensor at the calf near the ankle, better sensitivity can be obtained, and then the inertial measurement unit 9 and the second processing module 10 can more accurately and quickly identify the muscle contraction and movement intention of the leg.

[0040] In the embodiment, the knee joint rehabilitation device has four use postures: lying, sitting, standing and walking. Based on the wearable characteristics of the thigh fixing member 1, the calf fixing member 2, the motor 6, the electromyographic signal measuring unit 7 and the inertial measurement unit 9, no matter what posture, the electromyographic signal measuring unit 7 and the inertial measurement unit 9 can accurately obtain signals, and are less interfered by the outside world, so that the present embodiment can support four different use postures: lying, sitting, standing and walking. Each posture can be used for rehabilitation training and treatment at different stages, from early passive movement to later functional training, making the rehabilitation process more comprehensive and effective. These different use postures cover a variety of daily life and sports scenes that users may face during the rehabilitation process. Starting from lying and sitting positions, used for the recovery of joint flexibility and stability, to standing and walking postures, used for muscle strength and functional training, the device can fully support the user's systemic rehabilitation needs. Each posture helps to adapt to the needs of users at different rehabilitation stages. For example, lying and sitting positions are suitable for the initial rehabilitation stage to help restore joint mobility and flexibility, while standing and walking are more suitable for functional recovery and daily activity simulation to help users restore normal gait and mobility. The device provides a variety of posture options, which not only enhances the user's comfort and experience, but also improves the treatment effect and user treatment compliance. When users perform rehabilitation training in different postures, they can more naturally simulate movements and activities in daily life, which is critical to the comprehensiveness and long-term effects of rehabilitation.

[0041] In the embodiment, the knee joint rehabilitation device has a passive mode for controlling the rotation of the motor 6 based on a predetermined output signal, and an active and passive combination mode for controlling the rotation of the motor 6 based on the output signal of the first processing module 8 or the second processing module 10. The passive mode controls the rotation of the motor 6 based on a predetermined input signal. In this mode, the device can provide passive motion assistance, and help the user to perform knee joint motion through the rotation of the motor 6. This is particularly important for the early stage of rehabilitation or the stage where the user needs auxiliary motion, and can effectively promote the activity and flexibility recovery of the joint. The active and passive combination mode controls the rotation of the motor 6 based on the output signal of the first processing module 8 or the second processing module 10. In this mode, the device can combine the active participation of the user to achieve more accurate and personalized rehabilitation training, and adjust the working mode and power output of the motor according to the user's exercise intention and exercise ability to achieve the best rehabilitation effect. The above two modes allow the selection of a suitable exercise mode according to the specific situation and rehabilitation stage of the user, from completely passive to active participation in different degrees of motion control. The device can provide each user with a personalized rehabilitation plan, which helps to improve the user's treatment compliance and rehabilitation effect, and ensure the effectiveness and safety of rehabilitation training. Through the flexible application of passive mode and active-passive combined mode, the effectiveness of rehabilitation equipment in promoting joint movement, enhancing muscle strength and improving functional recovery can be enhanced. Users can receive customized rehabilitation training at different rehabilitation stages and treatment goals, thereby improving the efficiency and effectiveness of the rehabilitation process.

[0042] In the embodiment, Figures 5 to 8 As shown, the control method of the active and passive combination mode of the knee joint rehabilitation equipment is shown, and the specific steps are as follows.

[0043] Step 1. After the user puts on the rehabilitation device and selects the active and passive combined mode, the inertial measurement unit 9 needs to be calibrated statically and dynamically, such as Figure 7 , 8 As shown, the calibration steps are as follows.

[0044] Step 1.1. Place the inertial measurement unit 9 on a stationary flat surface, ensuring that there is no external motion or vibration influence; Step 1.2. Record the output data of the accelerometer and gyroscope of the inertial measurement unit 9 when it is stationary, and collect data from tens of seconds to several minutes; Step 1.3. For the data on each axis, calculate its average value as the zero bias compensation parameter for static calibration; Step 1.4. Apply the calculated zero bias compensation parameters to the real-time data to reduce the static error; Step 1.5. After the user puts on the rehabilitation device, he first selects a certain posture among lying, sitting, standing and walking, and then selects the preset dynamic calibration parameters in the passive mode to control the rotation of the motor 6, uses the thigh fixing part 1 and the calf fixing part 2 to drive the thigh and calf movements, and records the output data of the inertial measurement unit 9; Step 1.6. Use the real data of the control movement to compare with the output data recorded by the inertial measurement unit 9 to identify and correct dynamic errors; Step 1.7. After completing the calibration, perform a secondary dynamic calibration verification to ensure that the performance of the inertial measurement unit 9 meets expectations.

[0045] Step 2. The user autonomously controls the leg movements, the electromyographic signal measurement unit 7 detects the electrical activity of the leg muscles, collects electromyographic data, and the inertial measurement unit 9 detects the acceleration and angular velocity of the knee joint or related parts on three axes.

[0046] Step 3. Determine whether the EMG data is normal. If the EMG data is determined to be within the normal range, proceed to step 4. If the EMG data is determined to be abnormal, proceed to step 5.

[0047] In this embodiment, normal EMG data should be within a specific amplitude range, and the frequency changes within a certain range. Abnormal conditions are manifested as signal amplitudes that are too high or too low, or abnormally narrow or abnormally wide frequency ranges. In addition, normal EMG data is relatively stable, and the waveform morphology conforms to the expected muscle activity pattern. Abnormal conditions may include instability of signal drift or noise, or abnormal waveform morphology. Detecting these changes by setting appropriate thresholds can help identify abnormalities.

[0048] In addition, the judgment can be made by detecting the consistency between the electromyographic data and the three-axis acceleration and angular velocity. The electromyographic data obtained by the electromyographic signal measuring unit 7 is correlated with the three-axis acceleration and angular velocity recorded by the inertial measurement unit 9. Abnormal electromyographic data may be inconsistent with the motion state, for example, the electromyographic does not show the expected activity in the motion phase expected by the inertial measurement unit 9, or the electromyographic shows data opposite to the expected activity.

[0049] Therefore, this embodiment determines whether the EMG data is abnormal by comprehensively considering parameters such as the amplitude, frequency, stability, and waveform shape of the signal, and also considers the consistency of the EMG data with the three-axis acceleration and angular velocity measured in real time.

[0050] In the embodiment, Figure 6 As shown, taking the calculation amount from small to large as the standard, according to the order of amplitude, frequency, stability, waveform shape, and consistency with the three-axis acceleration and angular velocity data, whether the electromyography data is normal is judged in turn. The specific steps are as follows.

[0051] Step 3.1. Amplitude analysis: determine whether the amplitude of the EMG data is within the normal range.

[0052] Use RMS value (root mean square) to represent the amplitude of EMG data

[0053] in: is a discrete time index, is the total number of data points, The electromyography data is The amplitude of the sampling points.

[0054] Set the threshold, the normal amplitude range is ,Require .like If the value exceeds the above range, it means that the signal has obvious noise, vibration or fault, and the EMG data is judged to be abnormal. Go to step 5. If it does not exceed the limit, further determination is made.

[0055] Step 3.2. Frequency analysis: determine whether the frequency of the EMG data is within the normal range.

[0056] EMG data Perform discrete Fourier transform and calculate the frequency domain components

[0057] in: is a discrete time index, is the total number of data points, is the index of the frequency domain component, ranging from 0 to , is an imaginary unit, The electromyography data is frequency components, is the angular frequency of each frequency component.

[0058] Calculate the magnitude of the frequency domain components

[0059] in: and They are The real and imaginary parts of .

[0060] Calculate specific frequency band Total power within

[0061] Total Power It is the sum of the powers of all frequency components in the frequency band, indicating the signal energy in the frequency band.

[0062] Set the threshold, the normal power range is ,Require .like If the value exceeds the above range, it means that there are too obvious or too weak signal components in the frequency band, and the EMG data is judged to be abnormal. Go to step 5. If it does not exceed the limit, further determination is made.

[0063] Step 3.3. Stability analysis: determine whether the stability of the EMG data is normal.

[0064] Calculating EMG data Standard Deviation

[0065] in: is a discrete-time index, is the total number of data points, The electromyography data is The amplitude of the sampling points, yes expected value.

[0066] Set the standard deviation threshold. The normal standard deviation range is ,Require .like If the signal is beyond the above range, it means that the signal stability is poor, and the EMG data is judged to be abnormal, and then go to step 5. If it does not exceed the limit, further judgment is made.

[0067] Step 3.4. Waveform morphology analysis: determine whether the waveform morphology of the EMG data conforms to the expected muscle activity pattern.

[0068] Knee joint rehabilitation movements are usually cyclical reciprocating knee flexion or leg extension movements. Therefore, the features extracted from the EMG data during the specific waveform morphology analysis process usually include peak value, mean value, irregular peak value and cycle length, etc. The peak value and mean value have been verified in steps 3.1 and 3.3, so this step is mainly used to determine the irregular peak value and cycle length.

[0069] for EMG data within cycles, each cycle Divided into sample points, by finding The local maximum of the sample points determines the local peak , and calculate the local peak value in all cycles Standard Deviation

[0070] in: is the period number index, is the total number of cycles, is the local peak value of the EMG data in each cycle, yes expected value.

[0071] Set the standard deviation threshold. The normal standard deviation range is ,Require .like If the waveform is outside the above range, it means that the waveform is irregular, and the EMG data is judged to be abnormal. Go to step 5. If it does not exceed the limit, further judgment is made.

[0072] Calculate the duration of each cycle

[0073] in: is the length of a cycle, and Respectively represent the time points of two adjacent consecutive peaks.

[0074] calculate The standard deviation of the cycle length within a cycle

[0075] in: yes expected value.

[0076] Set the standard deviation threshold. The normal standard deviation range is ,Require .like If the waveform is outside the above range, it means that the waveform is irregular, and the EMG data is judged to be abnormal. Go to step 5. If it does not exceed the limit, further judgment is made.

[0077] In reality, however, knee rehabilitation exercises are highly autonomous, and the duration of each cycle may vary greatly. Therefore, this embodiment does not use the cycle length as a conventional feature of waveform morphology analysis, but only calls it out for use in specific exercise modes or during the debugging phase.

[0078] Step 3.5. Consistency analysis, determine the consistency between the EMG data and the real-time three-axis acceleration and angular velocity data.

[0079] Time domain analysis can directly compare the synchronization and amplitude changes of signals in time, so it is possible to evaluate the synchronization between the muscle activity level measured by the electromyographic signal measurement unit 7 and the three-axis acceleration or angular velocity measured by the inertial measurement unit 9. This embodiment uses the mean of the electromyographic data, acceleration and angular velocity within a fixed time window for consistency analysis to achieve the purpose of simplifying the calculation. The specific steps are as follows.

[0080] Step 3.5.1. Data preprocessing.

[0081] choose Continuous cycles As a fixed time window for analysis, each cycle Divided into Sample points, use timestamps or interpolation methods to ensure that the data is aligned within the window, and calculate the fixed time window Cycle Intramural electromyography data (expressed as voltage amplitude), triaxial acceleration (expressed as ) and the three-axis angular velocity (expressed in )

[0082] in: is the period number index, is the total number of cycles, is a discrete time index, is the total number of data points in each cycle, The electromyography data is The amplitude of the sampling points, , and is the triaxial acceleration at In the cycle The amplitude of the sampling points, , and is the angular velocity of the three axes In the cycle The amplitude of the sampling points, It is The mean amplitude of the electromyography data in a cycle, It is The average value of the three-axis acceleration amplitude within a cycle, It is The average value of the angular velocity amplitude of the three axes within a period.

[0083] Step 3.5.2. Calculate the correlation coefficient.

[0084] For internal electromyography data and triaxial acceleration

[0085] For the internal electromyography data and the three-axis angular velocity

[0086] in: yes and The covariance of yes and The covariance of , and They are , and The standard deviation of is the Pearson correlation coefficient between the internal EMG data and the triaxial acceleration, is the Pearson correlation coefficient between the intra-EMG data and the triaxial angular velocity.

[0087] Step 3.5.3. Consistency judgment.

[0088] The Pearson correlation coefficient measures the degree of linear relationship between two sets of data. Its value ranges from -1 to 1. A correlation coefficient close to 1 or -1 indicates that there is a strong linear relationship between the data. A correlation coefficient close to 0 indicates a weak linear relationship and possible inconsistency between the data.

[0089] Set the correlation coefficient threshold and ,Require and .like and If the value exceeds the above range, it indicates that the EMG data is consistent with the real-time three-axis acceleration and angular velocity data. This is used to determine that the EMG data is abnormal and go to step 5. and If it does not exceed, it is judged that the electromyography data is normal, and the process goes to step 4. In this embodiment, Take 0.7, Take 0.5.

[0090] This embodiment uses correlation analysis to determine the consistency between the electromyography data and the real-time three-axis acceleration and angular velocity data. Regression analysis can also be used for determination. The general idea is as follows.

[0091] Construct a linear regression model of the intermittent EMG data and the real-time triaxial acceleration and angular velocity

[0092] in: , and They are electromyography data, three-axis acceleration and three-axis angular velocity, is the intercept, and is the regression coefficient, is the error term. The historical data of healthy users are used to train the regression model to fit the relationship between the EMG data and the real-time three-axis acceleration and angular velocity. , , and value.

[0093] When it is necessary to judge the consistency between the EMG data and the real-time triaxial acceleration and angular velocity data, the goodness of fit is calculated ( value) to measure the variability between the model and the real-time data. The higher the value, the better the regression model can explain the changes in the EMG data, indicating that the triaxial acceleration and angular velocity data are consistent with the EMG data; if Low values ​​indicate that the model does not fit well and there may be inconsistencies in the data.

[0094] Generally speaking, it is more accurate to combine the results of correlation analysis and regression analysis. The value is also high, indicating that there is good linear consistency between the EMG data and the acceleration and angular velocity data. On the contrary, if both results are low, there may be inconsistency. In this embodiment, the correlation analysis can be used to make a more accurate consistency judgment, and even if a misjudgment occurs, in most cases the consistency is judged as inconsistency, which does not affect the normal use of the rehabilitation equipment. In addition, there are differences in health status and age between different users, which will reduce the Therefore, this embodiment only uses correlation analysis to determine the linear consistency between the electromyography data and the acceleration and angular velocity data.

[0095] Step 4. If the EMG data is normal, the first processing module 8 identifies the muscle contraction and movement intention of the leg according to the EMG data, and controls the rotation of the motor 6 based on the output signal of the first processing module 8, and uses the thigh fixing part 1 and the calf fixing part 2 to drive the thigh and calf to perform rehabilitation movements.

[0096] Step 5. If the EMG data is abnormal, the second processing module 10 performs time domain-frequency domain data conversion on the acceleration values ​​of the knee joint or related parts in multiple directions, and compares the amplitude of the frequency domain data with the reference value, and determines the movement intention of the leg based on the comparison result, and controls the rotation movement of the motor 6 based on the output signal of the second processing module 10, and utilizes the thigh fixing part 1 and the calf fixing part 2 to drive the thigh and calf to perform rehabilitation movements.

[0097] In the embodiment, the second processing module 10 uses the acceleration and angular velocity data acquired by the inertial measurement unit 9 to determine the movement intention of the knee joint. The specific steps are as follows.

[0098] Step 5.1. Data acquisition.

[0099] The inertial measurement unit 9 is used to measure the acceleration and angular velocity of the knee joint or related parts on three axes, and collects discrete time series data. and , respectively, at discrete time points The collected acceleration data and angular velocity data.

[0100] Step 5.2. Time domain to frequency domain conversion.

[0101] Since the inertial measurement unit 9 collects discrete time series data and , that is, the acceleration and angular velocity values ​​are collected at fixed time intervals, so the second processing module 10 uses discrete Fourier transform to convert the acceleration data and angular velocity data into time domain and frequency domain.

[0102] in: is the total number of data points, is the index of the frequency domain component, ranging from 0 to , is an imaginary unit, This is the acceleration data. frequency components, is the angular velocity data frequency components, is the angular frequency of each frequency component.

[0103] Step 5.3. Amplitude calculation.

[0104] Calculate the amplitude of acceleration and angular velocity in the frequency domain respectively

[0105] in: and They are The real and imaginary parts of and They are The real and imaginary parts of .

[0106] Step 5.4. Compare the amplitude with the reference value.

[0107] The calculated amplitude is compared with the preset reference value to determine the leg movement intention. The reference values ​​of acceleration and angular velocity are set to and , the amplitude of the current acceleration and angular velocity in the frequency domain and Compare with the reference value to get the acceleration amplitude difference and angular velocity amplitude difference

[0108] Action intention judgment: setting acceleration threshold With angular velocity threshold ,if and , indicating that the knee joint is performing a certain specific knee flexion or leg extension movement, otherwise it indicates that the movement state is stable or there is no significant movement intention.

[0109] The control method of the knee joint rehabilitation device of this embodiment has the following advantages in the active and passive combined mode.

[0110] (1) The user's muscle activity, joint angle and movement speed can be monitored in real time through the electromyographic signal sensor 7 and the inertial measurement unit 9. This real-time data feedback can help rehabilitation professionals more accurately evaluate the user's motor ability and rehabilitation progress, thereby adjusting the rehabilitation plan and optimizing the treatment effect.

[0111] (2) The electromyographic data state can more accurately reflect the user's actual movement intention than the acceleration and angular velocity of the knee joint or related parts on the three axes. Therefore, the first processing module 8 automatically identifies the user's movement intention and adjusts the rotational movement of the motor 6 according to different electromyographic data states. This control method makes rehabilitation training more targeted and effective, and can be dynamically adjusted according to the user's actual muscle activity ability, thereby improving the efficiency and effect of rehabilitation training.

[0112] (3) In some rehabilitation stages, the electromyographic data will be in an abnormal state. At this time, the first processing module 8 is difficult to identify the user's action intention. At this time, the second processing module 10 analyzes the data through time domain-frequency domain conversion and adjusts the control strategy of the motor 6 accordingly. This processing capability improves the adaptability of the device to different users and effectively responds to abnormal muscle electrical activity caused by changes in the user's physiological state.

[0113] (4) Static calibration and dynamic calibration processes ensure that the inertial measurement unit 9 provides accurate and reliable data during motion. Static calibration records the sensor output in a stationary state and calculates the zero bias compensation parameters to effectively reduce static errors; dynamic calibration compares the actual motion data with the output data recorded by the sensor to identify and correct dynamic errors, thereby improving the accuracy and reliability of the data. Completion of the calibration process ensures the performance stability of the inertial measurement unit during the use of the device. This is very important for long-term rehabilitation training, which can maintain the consistency and reliability of the equipment, thereby improving the user's treatment experience and rehabilitation effect.

[0114] (5) Furthermore, the accurately calibrated inertial measurement unit 9 can also provide more precise motion monitoring and control to ensure the safety of movement and the comfort of the user during the rehabilitation process. Through dynamic calibration, the response of the sensor can be adjusted in time to adapt to different rehabilitation training needs and motion states, thereby ensuring the safety of the user and the progress of rehabilitation.

[0115] Obviously, the above embodiments of the present invention are only examples for explaining the present invention, and are not intended to limit the implementation methods of the present invention. Other obvious changes or modifications derived from the essence of the present invention still fall within the protection scope of the present invention.

Claims

1. A multi-mode and multi-posture knee joint rehabilitation device, characterized in that: include: The thigh fixing member (1) and the calf fixing member (2) are used to fix the thigh part and the calf part of the leg requiring rehabilitation, respectively; An inner joint component (3) is rotatably connected to the inner sides of the thigh fixing component (1) and the calf fixing component (2); The outer joint assembly (4) comprises a rotating shaft (401) and a first rotating plate (402) and a second rotating plate (403) which are hinged to each other and are respectively fixed to the thigh fixing member (1) and the calf fixing member (2); A double lasso transmission assembly (5) is used to drive the second rotating plate (403) to rotate in the same manner as the first rotating plate (402); The motor (6) is fixed to the waist or back and is in driving connection with the double lasso transmission assembly (5); An electromyographic signal measuring unit (7) is used to detect the electrical activity of the leg muscles and collect electromyographic data; A first processing module (8) identifies leg muscle contraction and movement intention based on electromyography data; An inertial measurement unit (9) for detecting acceleration and angular velocity of the knee joint or an associated part on three axes; The second processing module (10) performs time domain-frequency domain data conversion on the acceleration values ​​of the knee joint or related parts in multiple directions, compares the amplitude of the frequency domain data with a reference value, and determines the movement intention of the leg according to the comparison result; The control module (11) controls the rotation of the motor (6) based on a predetermined input signal and an output signal of the first processing module (8) or the second processing module (10).

2. The multi-mode and multi-posture knee joint rehabilitation device according to claim 1, characterized in that: The thigh fixing member (1) and the calf fixing member (2) are arched plates made of lightweight, hard materials, respectively covering the front sides of the thigh and calf, and are fixed by straps.

3. The multi-mode and multi-posture knee joint rehabilitation device according to claim 1, characterized in that: The medial joint assembly (3) comprises a third rotating plate (301), a connecting plate (302) and a fourth rotating plate (303) which are connected in sequence; the adjacent ends of the third rotating plate (301) and the fourth rotating plate (303) have mutually meshing transmission teeth; the upper end of the third rotating plate (301) and the lower end of the fourth rotating plate (303) are respectively fixed to the thigh fixing member (1) and the calf fixing member (2).

4. The multi-mode and multi-posture knee joint rehabilitation device according to claim 3, characterized in that: The installation positions of the first rotating plate (402), the third rotating plate (301) and the thigh fixing member (1) are adjustable, and the installation positions of the second rotating plate (403), the fourth rotating plate (303) and the calf fixing member (2) are adjustable.

5. The multi-mode and multi-posture knee joint rehabilitation device according to claim 1, characterized in that: The double lasso transmission assembly (5) comprises: An active rotating disk (501) rotates along with the output shaft of the motor (6); A driven rotating disk (502) is fixedly mounted on the second rotating plate (403); A bearing (503) supported between the driven rotating disk (502) and the rotating shaft (401); The double lasso (504) is transmission-connected between the active rotating disk (501) and the driven rotating disk (502).

6. The multi-mode and multi-posture knee joint rehabilitation device according to claim 1, characterized in that: The electromyographic signal measuring unit (7) is used for measuring the electrical activities of the quadriceps femoris and the gastrocnemius muscles; the inertial measurement unit (9) comprises an accelerometer and a gyroscope and is installed at a portion of the calf near the ankle.

7. The multi-mode and multi-posture knee joint rehabilitation device according to claim 1, characterized in that: It has four usage postures: lying, sitting, standing and walking.

8. A control method for a multi-mode and multi-posture knee joint rehabilitation device according to any one of claims 1 to 7, characterized in that: The invention has a passive mode for controlling the rotational movement of the motor (6) based on a predetermined output signal, and an active and passive combined mode for controlling the rotational movement of the motor (6) based on an output signal of a first processing module (8) or a second processing module (10).

9. The control method of the multi-mode and multi-posture knee joint rehabilitation device according to claim 8, characterized in that: The steps of active and passive combined mode are as follows: Step 1. The user puts on the rehabilitation equipment and selects the active and passive combination mode; Step 2. The user autonomously controls the leg movements, the electromyographic signal measurement unit (7) detects the electrical activity of the leg muscles, collects electromyographic data, and the inertial measurement unit (9) detects the acceleration and angular velocity of the knee joint or related parts on three axes; Step 3. According to the order of amplitude, frequency, stability, waveform shape, and consistency with the data of triaxial acceleration and angular velocity, determine whether the electromyography data is normal. If the electromyography data is determined to be within the normal range, proceed to step 4. If the electromyography data is determined to be abnormal, proceed to step 5. Step 4. If the electromyographic data is in a normal state, the first processing module (8) identifies the muscle contraction and movement intention of the leg according to the electromyographic data, and controls the rotation of the motor (6) based on the output signal of the first processing module (8), and uses the thigh fixing member (1) and the calf fixing member (2) to drive the thigh and calf to perform rehabilitation movements; Step 5. If the electromyography data is abnormal, the second processing module (10) performs a time-domain-frequency-domain data conversion on the acceleration values ​​of the knee joint or related parts in multiple directions, compares the amplitude of the frequency-domain data with the reference value, and determines the movement intention of the leg based on the comparison result, and controls the rotation movement of the motor (6) based on the output signal of the second processing module (10), and uses the thigh fixing member (1) and the calf fixing member (2) to drive the thigh and calf to perform rehabilitation movements.

10. The control method of the multi-mode and multi-posture knee joint rehabilitation device according to claim 9, characterized in that: Step 1 also includes static calibration and dynamic calibration of the inertial measurement unit (9); The steps for static calibration are: Step 1.

1. Place the inertial measurement unit (9) on a stationary flat surface, ensuring that there is no external motion or vibration influence; Step 1.

2. Record the output data of the accelerometer and gyroscope of the inertial measurement unit (9) when the unit is stationary, and collect data for tens of seconds to several minutes; Step 1.

3. For the data on each axis, calculate its average value as the zero bias compensation parameter for static calibration; Step 1.

4. Apply the calculated zero bias compensation parameters to the real-time data to reduce the static error; The dynamic calibration steps are: Step 1.

5. After the user puts on the rehabilitation device, he first selects a certain posture of lying, sitting, standing or walking, and then selects the dynamic calibration parameters preset in the passive mode to control the rotation movement of the motor (6), uses the thigh fixing member (1) and the calf fixing member (2) to drive the thigh and calf movement, and records the output data of the inertial measurement unit (9); Step 1.

6. Use the real data of the control motion to compare with the output data recorded by the inertial measurement unit (9) to identify and correct dynamic errors; Step 1.

7. After completing the calibration, perform a secondary dynamic calibration verification to ensure that the performance of the inertial measurement unit (9) meets expectations.

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