Knee osteoarthritis gait rehabilitation limit cycle evaluation method, system and device

Abstract

The invention discloses a knee osteoarthritis gait rehabilitation limit cycle assessment method, system and device, and belongs to the technical field of medical diagnosis rehabilitation. The method comprises the following steps: S1, establishing a reference database of gaits based on healthy people; s2, gait data of the patient are collected through an optical motion capture system; s3, constructing a gait limit loop of the patient according to the gait data of the patient, and extracting feature parameters of the gait limit loop; s4, determining a gait feature score of the patient by comparing the feature parameters of the gait limit ring of the patient with the reference feature parameters, so as to obtain the condition of the knee osteoarthritis of the patient; and S5, preparing a rehabilitation scheme aiming at the patient according to the condition of the knee osteoarthritis of the patient. The gait characteristic and rehabilitation progress of the patient can be objectively and quantitatively evaluated, and the diagnosis and treatment efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical diagnosis and rehabilitation, and in particular relates to a method, system and device for evaluating a limit cycle of gait rehabilitation of knee osteoarthritis. Background Art

[0002] Knee osteoarthritis (KOA) is a common degenerative joint disease that affects approximately 250 million people worldwide, seriously affecting the quality of life of patients. With the aging of the population and the increase in the number of obese people, the incidence of KOA continues to rise.

[0003] Traditional KOA assessment methods mainly rely on imaging examinations (such as X-rays, MRI) and subjective questionnaires (such as the WOMAC index), lacking objective and quantitative functional assessment methods. Gait analysis, as an important method for assessing lower limb function, has potential application value in the diagnosis and treatment of KOA. However, existing gait assessments are mostly qualitative analyses with complex equipment and long time consumption, which limits their widespread clinical application.

[0004] The concept of limit cycle in dynamic system theory is to describe the repetitive periodic trajectory of the system in long-term behavior; human walking is a periodic motion, and this repetitive motion pattern can be described by limit cycle. For gait, although the initial pace and gait will be different, after a few steps, the gait will tend to be stable and form a stable periodic motion pattern. Therefore, for humans, the knee joint part will show a generally similar limit cycle diagram during normal walking, and the knee joint condition can be compared and analyzed based on this limit cycle.

[0005] Therefore, how to provide a knee osteoarthritis rehabilitation assessment method based on gait limit cycles is an urgent problem to be solved at this stage. Summary of the invention

[0006] The present invention aims to solve one of the technical problems in the above-mentioned related art at least to a certain extent.

[0007] To this end, the purpose of the present invention is to provide a method, system and device for evaluating the limit cycle of gait rehabilitation of knee osteoarthritis, which can objectively and quantitatively evaluate the patient's gait characteristics and rehabilitation progress, and improve the efficiency of diagnosis and treatment.

[0008] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0009] An embodiment of the present invention provides a method for evaluating a limit cycle of gait rehabilitation for knee osteoarthritis, the method comprising:

[0010] S1. Establish a gait benchmark database based on healthy people;

[0011] S2, collecting the patient's gait data through an optical motion capture system;

[0012] S3, constructing a gait limit cycle of the patient according to the gait data of the patient, and extracting characteristic parameters of the gait limit cycle;

[0013] S4. Determine the patient's gait characteristic score by comparing the characteristic parameters of the patient's gait limit cycle with the baseline characteristic parameters, thereby obtaining the patient's knee osteoarthritis condition;

[0014] S5. Prepare a rehabilitation plan for the patient based on the patient's knee osteoarthritis condition.

[0015] In addition, the knee osteoarthritis gait rehabilitation limit cycle assessment method according to the present invention may also have the following additional technical features:

[0016] In some embodiments, the gait data in step S2 includes step length, step speed and knee joint angle change.

[0017] In some embodiments, the content of step S3 includes calculating the knee joint angular velocity and angular acceleration according to the patient's gait data, and drawing a limit cycle curve according to the calculated knee joint angular velocity and angular acceleration; extracting characteristic parameters of the limit cycle including the circumference, area and energy of the limit cycle.

[0018] In some embodiments, the method further includes: constructing a personal history database based on the patient's previous gait assessments, and comparing the characteristic parameters of the patient's currently assessed gait limit cycle with the personal history characteristic parameters to determine the patient's degree of recovery.

[0019] In some of the embodiments, the area of ​​the limit cycle is calculated using a Gaussian area formula.

[0020] In some of the embodiments, the perimeter of the limit cycle is obtained by accumulating the distance between each adjacent point on the limit cycle using the Euclidean distance method.

[0021] In some embodiments, the energy calculation formula of the limit cycle is:

[0022]

[0023] Where U is the moment of inertia of the knee joint, is the angular velocity of each point.

[0024] In some embodiments, the gait characteristic score of the patient in step S4 is calculated as follows:

[0025]

[0026] Where A0, P0, and E0 are the area, perimeter, and energy of the benchmark limit cycle, respectively;

[0027] A, P, and E are the area, perimeter, and energy of the patient's current gait limit cycle, respectively.

[0028] The embodiment of the present invention further provides a knee osteoarthritis gait rehabilitation limit cycle assessment system, the system can implement the steps of the knee osteoarthritis gait rehabilitation limit cycle assessment method as described in any one of the above items; the system comprises:

[0029] The database module is used to build a benchmark database of gait based on healthy people and a personal history database of patients' gait assessments;

[0030] An optical motion capture module, used for collecting gait data of the patient through an optical motion capture system;

[0031] A characteristic parameter extraction module, used for constructing a gait limit cycle of the patient according to the gait data of the patient, and extracting characteristic parameters of the gait limit cycle;

[0032] A comparison module determines the patient's gait characteristic score by comparing the characteristic parameters of the patient's gait limit cycle with the baseline characteristic parameters, thereby obtaining the patient's knee osteoarthritis condition; and / or compares the characteristic parameters of the patient's currently assessed gait limit cycle with the personal historical characteristic parameters to determine the patient's degree of recovery;

[0033] The rehabilitation program formulation module prepares a rehabilitation program for the patient based on the patient's current condition of knee osteoarthritis.

[0034] An embodiment of the present invention also provides a knee osteoarthritis gait rehabilitation limit cycle assessment device, comprising a processor and a memory, wherein the memory stores a software program, and when the processor runs the software program, the steps of the knee osteoarthritis gait rehabilitation limit cycle assessment method as described in any one of the above can be implemented.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] In the embodiment of the present invention, the provided knee osteoarthritis gait rehabilitation limit cycle assessment method utilizes the gait limit cycle characteristic parameters to objectively reflect the functional state of the knee joint and avoid the deviation of subjective assessment;

[0037] In the embodiment of the present invention, the provided knee osteoarthritis gait rehabilitation limit cycle assessment method combines transverse and longitudinal data to provide personalized rehabilitation assessment and guidance for patients, thereby effectively improving the treatment effect;

[0038] In the embodiment of the present invention, the provided limit cycle assessment method for gait rehabilitation of knee osteoarthritis has a simple data collection and analysis process, is suitable for clinical environments, and saves time and resources;

[0039] The knee osteoarthritis gait rehabilitation limit cycle assessment method of the present invention can accurately assess the rehabilitation progress of KOA patients, guide personalized treatment and rehabilitation programs, and has broad clinical application prospects.

[0040] The knee osteoarthritis gait rehabilitation limit cycle assessment system and device of the present invention can implement the steps of the knee osteoarthritis gait rehabilitation limit cycle assessment method, and thus at least have all the features and advantages of the knee osteoarthritis gait rehabilitation limit cycle assessment method, which will not be repeated here. Additional aspects and advantages of the present invention will be partially given in the following description, and partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic flow chart of a method for evaluating a limit cycle of gait rehabilitation for knee osteoarthritis disclosed in one embodiment of the present invention;

[0042] Figure 2 A schematic diagram of marker arrangement and a cable tie binding diagram disclosed in an embodiment of the present invention, showing the positions of markers on the legs and knee joints;

[0043] Figure 3 A schematic diagram of data acquisition disclosed in an embodiment of the present invention shows the walking process of a subject under an optical motion capture system;

[0044] Figure 4 A walking diagram of a human body 3D model after marker points are marked according to an embodiment of the present invention; wherein (a) and (b) are walking diagrams in frontal and side views, respectively;

[0045] Figure 5 This is a qualisys 3D mode diagram disclosed in one embodiment of the present invention, and the movement of the marker points can be clearly observed during subsequent walking;

[0046] Figure 6The angular velocity and angular acceleration change curves of the thigh, calf and knee joint disclosed in an embodiment of the present invention reflect the dynamic characteristics of the knee joint during the gait cycle; wherein (a) and (b) are angle curves of the right and left thighs in a certain time period, respectively; (c) and (d) are angle curves of the right and left calves in a certain time period, respectively; (e) and (f) are angle curves of the right and left knee joints in a certain time period, respectively; (g) is an angular velocity curve of the angular velocity of the right calf in time periods 1 and 2 respectively obtained after data processing; (h) is an angular acceleration curve of the right calf in time periods 1 and 2 respectively obtained after data processing;

[0047] Figure 7 A curve showing changes of selected marking points over time disclosed in one embodiment of the present invention;

[0048] Figure 8 A schematic diagram of a gait limit cycle characteristic spectrum disclosed in an embodiment of the present invention shows a limit cycle curve with angular velocity and angular acceleration as coordinates. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The embodiments of the present invention are described in detail below through specific embodiments and application scenarios in conjunction with the accompanying drawings.

[0051] See also Figure 1 As shown, in some embodiments of the present invention, a method for evaluating the limit cycle of gait rehabilitation for knee osteoarthritis is provided, the steps comprising:

[0052] Step 1: Data Collection

[0053] Use an optical motion capture system such as Qualisys to collect gait data when the patient walks, including parameters such as step length, step speed, knee joint angle change, etc. When using an optical motion capture system such as Qualisys for capture, the captured signal includes the spatial coordinates of the marker points installed on the leg and knee joint, defines a fixed coordinate system, and determines the position of the camera and the coordinate system.

[0054] In some embodiments of the present invention, no less than eight high-resolution cameras are installed in the optical motion capture system and placed around the patient's gait trajectory to form 360° all-round coverage. The system is captured by setting no less than 10 marker points on the legs, knee joints and ankles, and a fixed coordinate system is defined to ensure the accuracy of data acquisition. The data acquisition frequency is set to 100 to 120 frames per second to meet the high-precision requirements of kinematic data and ensure that continuous gait features are captured during dynamic changes in gait.

[0055] Step 2: Establishment of gait database

[0056] Establishment of horizontal indicators: Collect a large amount of gait data from healthy people of different ages and genders, establish a normal gait database, and provide a reference standard for evaluation;

[0057] Establishment of longitudinal indicators: Regularly collect gait data of KOA patients, establish a personal historical gait database, and track rehabilitation progress.

[0058] Among them, the horizontal indicator analysis is to establish a benchmark database based on the gait data of healthy people, and analyze the gait characteristics of people of different age groups through big data, including limit cycle area, energy and shape complexity. Each healthy group contains 100 cases, and different age groups are divided into 20-40 years old, 40-60 years old, and over 60 years old. The longitudinal indicator analysis is to divide KOA patients into three groups according to mild, moderate and severe, each containing 50 cases, establish a graded gait model, and extract the gait characteristic values ​​of each group of patients as a longitudinal comparison benchmark.

[0059] Step 3: Construction of gait limit cycle feature map

[0060] Use the corresponding motion capture system software such as QTM software to process the collected data and calculate the angular velocity and angular acceleration of the knee joint during walking. Use the angular velocity as the horizontal coordinate and the angular acceleration as the vertical coordinate to draw the gait limit cycle curve and extract characteristic parameters, including circumference, area, and energy.

[0061] In the above-mentioned embodiment, the extent of foot lifting can be determined by the height of the marking point at the ankle from the ground, and the corresponding motion capture system software, such as QTM software, can be used to record and analyze the changes in the movement process of the marking points on the thigh and calf in the sagittal plane, evaluate the range of motion of the knee joint, and process the collected data using the corresponding motion capture system software, such as QTM software, to generate a phase diagram of the knee joint angular velocity and angular acceleration.

[0062] The collected three-dimensional gait data is analyzed using the corresponding motion capture system software such as QTM analysis software to generate a gait limit cycle characteristic map. The angular velocity and angular acceleration of the knee joint are obtained at each time point and used as the horizontal and vertical axes respectively to draw the instantaneous trajectory of the gait limit cycle.

[0063] Step 4: Rehabilitation Assessment

[0064] By comparing the patient's limit cycle characteristic parameters with the standard values ​​of the normal population, as well as the patient's own data at different stages of rehabilitation, the rehabilitation effect and progress can be evaluated to guide subsequent treatment and rehabilitation plans.

[0065] In the above implementation, the changes in the characteristic parameters of the limit cycle at different periods and different rehabilitation stages are used to evaluate the rehabilitation progress and efficacy. The longitudinal comparison is conducted by analyzing the changes in the characteristics of the limit cycle of the patient's initial rehabilitation and current gait to determine the rehabilitation effect. If the area of ​​the limit cycle increases and the complexity of the shape decreases, it indicates that the gait is tending to be normal. The change value of the rehabilitation progress is quantified by Matlab programming, and the output report contains key rehabilitation indicators, such as the area of ​​the limit cycle (unit: cm 2 ), circumference (unit: cm), energy (unit: J).

[0066] The limit cycle area is used to quantify the stability of the gait; the more stable the gait, the larger the limit cycle area is usually. The limit cycle area calculation uses the Gaussian area formula (Shoelace Formula) to calculate the area of ​​a closed curve (limit cycle):

[0067]

[0068] Among them, i is an integer used to identify each point on the curve, starting from 1 and increasing to n-1 in sequence, used to traverse all points on the curve; is the rate of change of the angle θ at the i-th point with time; Represents the first derivative of an angle The rate of change of the independent variable over time, that is, how fast the angular velocity changes; Indicates how fast the angle changes at the i+1th point; Indicates how fast the angular velocity changes at the i+1th point.

[0069] The circumference of the limit cycle is used to measure the variability of gait; a longer circumference indicates a larger gait variability and possible instability. The circumference of the limit cycle is calculated using the Euclidean distance method to accumulate the distances of each adjacent point on the limit cycle. The formula is:

[0070]

[0071] in, Indicates how fast the angle changes at the i+1th point; Indicates how fast the angular velocity changes at the i+1th point. Let is the discrete data point of the limit cycle curve, that is, the coordinate sequence of angular velocity and angular acceleration, n is the number of data points on the curve, and are the discrete coordinate values ​​of angular velocity and angular acceleration respectively.

[0072] The limit cycle energy reflects the dynamic characteristics of gait and can reveal the total energy consumption of gait in the entire movement cycle. The formula for calculating the limit cycle energy is:

[0073]

[0074] Where I is the moment of inertia of the knee joint, is the angular velocity of the i-th point.

[0075] The degree of rehabilitation achievement is used to quantify the patient's rehabilitation progress and reflect the degree to which the gait limit cycle characteristics are close to the health benchmark. The ratio of the current limit cycle characteristic value to the health benchmark is calculated, and the degree of rehabilitation achievement is obtained by combining various indicators. The formula is:

[0076]

[0077] Among them, A0, P0, and E0 are the limit cycle area, perimeter, and energy baseline values ​​of healthy people, respectively. This formula represents the degree of closeness of the current gait characteristics to the healthy gait. The closer the value is to 100%, the more ideal the rehabilitation progress.

[0078] The circumference of the limit cycle in the characteristic map shows the difference in gait, the area represents the stability of gait, and the energy reflects the dynamics of gait. Through numerical calculation and cumulative analysis of each feature, that is, numerical calculation of the above features is performed on the limit cycles of multiple cycles, and then the results are accumulated or averaged to obtain the quantitative map of the patient's gait limit cycle, providing intuitive rehabilitation evaluation indicators.

[0079] Embodiment 1:

[0080] A limit cycle assessment method for gait rehabilitation of knee osteoarthritis, comprising the following steps:

[0081] Step 1: Data Collection

[0082] Stick reflective markers on key locations of the patient's legs and knee joints, such as Figure 2 As shown, the subjects walked in a natural gait in a laboratory environment. An optical motion capture system such as Qualisys was used to collect gait data, including step length, step speed, knee joint angle changes, etc.

[0083] The captured signals are the spatial coordinates of markers installed on the legs and knee joints, and a fixed coordinate system is defined and the positional relationship between the camera and the coordinate system is determined to obtain clearer and more reliable spatial coordinates.

[0084] Furthermore, no less than eight high-resolution cameras are installed in the optical motion capture system and placed around the patient's gait trajectory to form 360° full coverage, such as Figure 3 As shown, no less than 10 marker points are set at the legs, knee joints and ankles for capture, and a fixed coordinate system is defined to ensure the accuracy of data acquisition. The data acquisition frequency is set to 100-120 frames / second to meet the high-precision requirements of kinematic data and ensure that continuous gait features are captured during dynamic changes in gait.

[0085] Make sure there are no extra reflective points in the environment to reduce errors, measure data more accurately and calculate results. Therefore, the best option is to draw the curtains and close the doors and windows in a closed room, wear clothes and shoes without reflective points, and temporarily remove the lenses of glasses. After collecting data, you can open the curtains and put on glasses again.

[0086] In addition, data collection requires patients to walk within a specified range. For the range that eight high-resolution cameras can capture, the most suitable range is a rectangular area within 70 cm in width and 400 cm in length. Patients can walk slowly from one end of the length range to the other end (such as Figure 4 As shown in the figure, during this process, several cameras collect the real-time position data of the reflective points, and after the whole process, the corresponding motion forms of each joint marked by the marking points can be generated.

[0087] Furthermore, the height of the ankle marker from the ground is used to determine the extent of the foot lift, and the corresponding motion capture system software such as QTM software is used to record and analyze the changes in the movement of the markers on the thigh and calf in the sagittal plane (such as Figure 5 Assess the knee's range of motion.

[0088] Use the corresponding motion capture system software such as QTM software to process the collected data and generate the phase diagram of knee joint angular velocity and angular acceleration (such as Figure 6 shown).

[0089] Among them, the surface composed of three marking points can be selected to analyze the motion state of this part (such as Figure 7 As shown in the figure, for example, by selecting the marking points of the knee joint and then selecting a movement time period, an image of the knee joint angle and angular acceleration changing with time in this time period can be generated.

[0090] Step 2: Create a gait database

[0091] By extensively collecting gait data from healthy people, a normal gait database is established, covering individuals of different ages, genders and body shapes. By analyzing the gait characteristics of people of different age groups through big data, including the circumference, area, energy and shape complexity of the limit cycle, a benchmark database based on the gait data of healthy people is constructed. Each healthy group in the benchmark database contains 100 cases, and different age groups are divided into 20-40 years old, 40-60 years old, and over 60 years old. The patient's gait limit cycle feature map is compared with the horizontal data in the benchmark database to detect gait differences. Horizontal data comparison refers to comparing the limit cycle data of the gait of patients with that of healthy people of the same age group in the benchmark database to obtain the gait difference between the patient's gait limit cycle and the gait limit cycle of healthy people.

[0092] For KOA patients, their gait data is collected regularly and a personal historical database is established for longitudinal comparison of the patients themselves to determine changes in their condition or recovery.

[0093] Furthermore, multiple KOA patients can be divided into three groups according to mild, moderate and severe conditions, and a graded gait model can be established. The gait characteristic values ​​of each group of patients can be extracted as a longitudinal comparison benchmark and the conditions after each stage of rehabilitation treatment can be used as a control. In this way, longitudinal comparative analysis can show the comparison with previous rehabilitation at each stage of rehabilitation. In the specific analysis, if the limit cycle area and energy values ​​are close to the benchmark of healthy people, it indicates that the rehabilitation is progressing well.

[0094] The establishment of the previous database and the horizontal and vertical comparisons can all be obtained through significant statistical analysis using software such as SPSS, thus ensuring the scientific nature of the analysis results.

[0095] The changes in the characteristic parameters of the limit cycle at different periods and different stages of rehabilitation are used to evaluate the progress and efficacy of rehabilitation. The longitudinal comparison is conducted by analyzing the changes in the characteristics of the limit cycle of the patient's gait at the initial stage of rehabilitation and at the current stage to judge the rehabilitation effect. If the area of ​​the limit cycle increases and the complexity of the shape decreases, it indicates that the gait is tending to be normal. The change value of the rehabilitation progress is quantified by calculation and output as a report. The report contains key rehabilitation indicators, such as the area of ​​the limit cycle (unit: cm 2 ), circumference (unit: cm) and energy (unit: J), etc.

[0096] Step 3: Construct gait limit cycle feature map

[0097] Using the collected data, the angular velocity and angular acceleration of the knee joint are calculated, the limit cycle curve is drawn, and the characteristic parameters are extracted, including the circumference, area and energy of the limit cycle.

[0098] The corresponding motion capture software system, such as QTM software, is used to process the collected data and calculate the angular velocity and angular acceleration of the knee joint during the gait cycle. The gait limit cycle curve is drawn with angular velocity as the horizontal coordinate and angular acceleration as the vertical coordinate.

[0099] Furthermore, the characteristic parameters of the above-mentioned extraction of limit cycles specifically include:

[0100] The area of ​​the limit cycle is extracted. The area can reflect the range of motion of the knee joint and the stability of the gait. The area of ​​the limit cycle is calculated using the Gaussian area formula (Shoelace Formula) to calculate the area of ​​the closed curve (limit cycle):

[0101]

[0102] Extract the circumference of the limit cycle, which can reflect the complexity of the gait. The circumference of the limit cycle is calculated by accumulating the distance of each adjacent point on the limit cycle using the Euclidean distance method. The formula is:

[0103]

[0104] in, is the discrete data point of the limit cycle curve, that is, the coordinate sequence of angular velocity and angular acceleration, n is the number of data points on the curve, and are the discrete coordinate values ​​of angular velocity and angular acceleration respectively.

[0105] The energy of the limit cycle is extracted, and the energy can represent the dynamic characteristics of the knee joint movement and the dynamics of the gait. The formula for calculating the energy of the limit cycle is:

[0106]

[0107] Where I is the moment of inertia of the knee joint, is the angular velocity of each point.

[0108] Step 4: Rehabilitation Assessment

[0109] By comparing the limit cycle characteristic parameters of patients with the standard values ​​of normal people, the difference from normal levels can be evaluated. Figure 8 As shown, there are significant differences in the limit cycle curves of patients before and after recovery.

[0110] Among them, the degree of rehabilitation achievement is used to quantify the patient's rehabilitation progress and reflect the degree to which the gait limit cycle characteristics are close to the health benchmark.

[0111] By calculating the ratio of the current limit cycle eigenvalue to the health benchmark, the rehabilitation achievement degree is obtained by combining various indicators. The formula is:

[0112]

[0113] Among them, A0, P0, and E0 are the limit cycle area, perimeter, and energy baseline values ​​of healthy people, respectively. This formula represents the degree of closeness of the current gait characteristics to the healthy gait. The closer the value is to 100%, the more ideal the rehabilitation progress.

[0114] The circumference of the limit cycle in the feature map shows the complexity of the gait, the area indicates the stability of the gait, and the energy reflects the dynamics of the gait. Through the numerical calculation and cumulative analysis of each feature, the quantitative map of the patient's gait limit cycle is obtained, and a horizontal comparison is made to determine the severity of the patient's condition, thereby providing an intuitive rehabilitation evaluation indicator. At the same time, the changes in the patient's limit cycle at different stages of rehabilitation are compared longitudinally to evaluate the patient's rehabilitation progress. For example, as rehabilitation training progresses, the area and energy of the limit cycle gradually approach normal values, and the shape complexity increases, indicating that the knee joint function has improved. Doctors can adjust the rehabilitation plan based on the results of each evaluation, provide personalized treatment suggestions, and improve the rehabilitation effect.

[0115] The parts of the present invention that are not described in detail may refer to the prior art or are known to those skilled in the art, and this embodiment does not limit this and will not be described in detail here.

[0116] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A limit cycle evaluation method for gait rehabilitation of knee osteoarthritis, characterized in that: The method comprises: S1. Establish a gait benchmark database based on healthy people; S2, collecting the patient's gait data through an optical motion capture system; S3, constructing a gait limit cycle of the patient according to the gait data of the patient, and extracting characteristic parameters of the gait limit cycle; S4. Determine the patient's gait characteristic score by comparing the characteristic parameters of the patient's gait limit cycle with the baseline characteristic parameters, thereby obtaining the patient's knee osteoarthritis condition; S5. Prepare a rehabilitation plan for the patient based on the patient's knee osteoarthritis condition.

2. The knee osteoarthritis gait rehabilitation limit cycle assessment method according to claim 1, characterized in that: The gait data in step S2 includes step length, step speed and knee joint angle change.

3. The knee osteoarthritis gait rehabilitation limit cycle assessment method according to claim 1, characterized in that: The content of step S3 includes calculating the knee joint angular velocity and angular acceleration according to the patient's gait data, drawing a limit cycle curve according to the calculated knee joint angular velocity and angular acceleration; and extracting characteristic parameters of the limit cycle including the circumference, area and energy of the limit cycle.

4. The method for evaluating the limit cycle of gait rehabilitation for knee osteoarthritis according to claim 1, characterized in that: The method further includes: constructing a personal history database based on the patient's previous gait assessments, and comparing the characteristic parameters of the patient's currently assessed gait limit cycle with the personal history characteristic parameters to determine the patient's degree of recovery.

5. The knee osteoarthritis gait rehabilitation limit cycle assessment method according to claim 3, characterized in that: The area of ​​the limit cycle is calculated using the Gaussian area formula.

6. The knee osteoarthritis gait rehabilitation limit cycle assessment method according to claim 3, characterized in that: The perimeter of the limit cycle is obtained by accumulating the distance between each adjacent point on the limit cycle using the Euclidean distance method.

7. The knee osteoarthritis gait rehabilitation limit cycle assessment method according to claim 3, characterized in that: The energy calculation formula of the limit cycle is: Where I is the moment of inertia of the knee joint, is the angular velocity of each point.

8. The knee osteoarthritis gait rehabilitation limit cycle assessment method according to claim 1, characterized in that: The patient's gait characteristic score in step S4 is calculated as follows: Where A0, P0, and E0 are the area, perimeter, and energy of the benchmark limit cycle, respectively; A, P, and E are the area, perimeter, and energy of the patient's current gait limit cycle, respectively.

9. A knee osteoarthritis gait rehabilitation limit cycle assessment system, characterized in that: The system can implement the steps of the knee osteoarthritis gait rehabilitation limit cycle assessment method according to any one of claims 1 to 8; the system comprises: The database module is used to build a benchmark database of gait based on healthy people and a personal history database of patients' gait assessments; An optical motion capture module, used for collecting gait data of the patient through an optical motion capture system; A characteristic parameter extraction module, used for constructing a gait limit cycle of the patient according to the gait data of the patient, and extracting characteristic parameters of the gait limit cycle; A comparison module determines the patient's gait characteristic score by comparing the characteristic parameters of the patient's gait limit cycle with the baseline characteristic parameters, thereby obtaining the patient's knee osteoarthritis condition; and / or compares the characteristic parameters of the patient's currently assessed gait limit cycle with the personal historical characteristic parameters to determine the patient's degree of recovery; The rehabilitation program formulation module prepares a rehabilitation program for the patient based on the patient's current condition of knee osteoarthritis.

10. A knee osteoarthritis gait rehabilitation limit cycle assessment device, comprising a processor and a memory, wherein a software program is stored in the memory, characterized in that: When the processor runs the software program, it can implement the steps of the knee osteoarthritis gait rehabilitation limit cycle assessment method as described in any one of claims 1 to 8.

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