Wearable robots, systems, and methods for correcting gait impairments

Abstract

A wearable robot (1000), system and method are provided for correcting a gait impairment, such as knee hyperextension, of a user. The wearable robot (1000) is an assistive lower extremity exoskeleton having a frame (1100, 1300, 1400) and a drive system (1200) to generate an assistive force (F) having a time, duration, and magnitude in accordance with a gait impairment mitigation strategy.

Description

Technical Field

[0001] A wearable robot, system, and method are provided for correcting gait impairments in users, such as knee hyperextension. The wearable robot is an assistive lower limb exoskeleton with a frame and an execution system to generate assistive forces with timing, duration, and amplitude based on gait impairment mitigation strategies. Background Technology

[0002] Gait disturbances and lower limb injuries caused by aging and pathological conditions such as neuromuscular and musculoskeletal disorders are among the leading causes of limited quality of life and loss of personal independence. For example, knee hyperextension is a very common problem in people affected by neurological disorders (where damage to neural pathways leads to knee weakness or loss of control, such as stroke, multiple sclerosis, cerebral palsy, muscular dystrophy, spinal cord injury, etc.) or in people with knee deformities or injuries.

[0003] The normal range of motion for an adult knee joint is 0° to 135°. During a normal gait cycle, full knee extension should generally not exceed 10°. Knee hyperextension typically manifests as an increase in full knee extension during the stance phase of the gait cycle. This can be mild, moderate, or severe, and can restrict movement and lead to other conditions by disrupting an individual's balance and gait patterns, including the development of asymmetrical gait patterns, pain, osteoarthritis, tendon or ligament injuries, etc.

[0004] Walking ability is an important goal in the treatment of any neurological disorder because this fundamental ability not only contributes to independent living and its associated psychological benefits, but also increases patient adherence to other treatment options, increases muscle strength, improves cardiovascular health, and helps restore or maintain cognitive function. Treatment of the underlying causes of knee hyperextension and corrective measures for chronic knee hyperextension are also highly needed.

[0005] Conventional treatment for knee hyperextension typically relies on gait training to optimize walking performance. Gait training focuses on guiding patients through exercises that complete the various components of the gait cycle, such as through direct intervention and guidance from a trained clinician, or using specialized treadmills and biofeedback devices to guide assisted exercises. While generally successful over the long term, gait training requires regular, monitored sessions and may take several years to show improvement. Outside of these relatively limited periods of direct clinical intervention and training, patients may still experience the negative effects of immobility and knee hyperextension, potentially prolonging the time required for successful treatment.

[0006] Braces, walkers, and other orthotic devices have been used as corrective measures for everyday “outside the lab” to meet the real-life needs of patients with knee hyperextension. For example, rigid braces can be designed to mechanically limit the range of motion of the knee joint and prevent hyperextension by forcibly stopping rotation at a given point. Other braces are designed with elastic elements to provide a resilient response to knee hyperextension by more progressively reducing it.

[0007] While some success has been found with these devices and related methods in mitigating the effects of knee hyperextension on gait cycles, the assistance provided to the knee cannot be tailored to the specific needs of the patient (such as weight, strength level, spasticity level, and other gait injuries) or replicate the gradual progression of a natural gait cycle. Interventions implemented in conventional corrective measures are often abrupt and passive, thus only intervening to counteract hyperextension once it has begun or otherwise negatively impacts other parts of the user's gait cycle. Known corrective measures cannot replicate the comfort and stability of natural movement. Significant challenges remain in designing therapeutic or corrective strategies that achieve a more natural gait and contribute to the effectiveness of clinical gait training.

[0008] In summary, there is a need for methods and systems capable of correcting gait injuries such as knee hyperextension, achieved by mimicking natural gait patterns. Furthermore, there is a need for methods and systems that can finely adapt to the individual user's characteristics and dynamically prevent knee hyperextension and other gait injuries, where an injury to one joint is corrected using a single device or by providing auxiliary torque at a single joint. For example, correction of knee hyperextension provides a more natural and comfortable gait. Additional gait training may also offer benefits, improving patient compliance and reducing the time required to achieve improvement through gait training alone. Summary of the Invention

[0009] One object of this disclosure is to provide improved methods and systems for correcting gait injuries in users, such as knee hyperextension. Another object of the invention is to dynamically counteract knee hyperextension by applying assistive forces at the hip level to correct knee joint patterns based on the individual characteristics of the user.

[0010] According to this disclosure, a system and method for correcting knee hyperextension using a wearable robot or, more specifically, a lower limb assistive exoskeleton are proposed. A novel assistive strategy for correcting knee hyperextension is provided, capable of assisting the user's actual needs by achieving a more natural gait. Correction of knee hyperextension is based on providing assistive forces to the user's limbs during the standing phase of the gait cycle. During the standing phase, flexion assistance can be provided at the user's hip joint, i.e., the thigh, to counteract knee hyperextension.

[0011] Wearable robots are used to assist movement and restore functional gait patterns, representing technological assistive tools that support everyday life scenarios. In the context of this disclosure, wearable robots are powered or passive exoskeletons. In powered exoskeletons, a wearable robot is a machine powered by a system of electric motors, pneumatic actuators, levers, hydraulic devices, or combinations of various technologies, allowing for increased strength and endurance during limb movement. Some wearable robots sense the user's movement and send signals to manage the robot's movement. Wearable robots can be positioned to fix, support, or move the shoulders, waist, and thighs, and can assist in movements involving lifting and grasping heavy objects. In passive exoskeletons, the exoskeleton is not powered, but it can provide mechanical benefits to the user. Wearable robots can improve rehabilitation programs for people with limb injuries and mobility impairments by providing coordination assistance in limb movement.

[0012] With assistive devices designed for individuals with mild lower limb injuries, wearable robots can assist in active lower limb movements by generating appropriate forces during the gait cycle to propel a portion of the limb, for example, by initiating the swing phase. Traditionally, wearable robot interventions have been limited to supporting these active movements to achieve a natural gait, and due to the restriction of forward movement during the standing phase, the irregularity of the standing phase of the gait cycle relies on similar concepts known in conventional braces and walkers to treat knee hyperextension.

[0013] More specifically, existing braces, walkers, orthotics, and assistive devices are all mono-joint devices configured to assist or correct a specific assisted joint by providing torque to induce more physiological patterns in that joint. These devices require direct application of force or resistance to the assisted joint and must be positioned at that joint. Existing devices require different equipment to treat each joint associated with gait impairment.

[0014] The assistance provided to the limb can be adapted to the characteristics of an individual user (e.g., weight, strength level, spasticity level, and other gait impairments) by adjusting at least the duration of flexion assistance, the duration of flexion assistance, or the amplitude of flexion assistance. According to this disclosure, the duration of flexion assistance can be defined as the center position of the flexion assistance profile measured in the form of 0-100% during the gait cycle or stride; the duration of flexion assistance can be defined as the width of the flexion assistance profile as a percentage during the gait cycle; and the amplitude of flexion assistance can be defined as the peak level of the assistive flexion torque provided to the user's limb during flexion assistance.

[0015] According to one embodiment, the system and method may include determining flexion assistance by identifying hyperextension of the user's knee during a gait cycle, determining the timing of the flexion assistance, determining the duration of the flexion assistance, and determining the initial amplitude of the flexion assistance. After the flexion assistance is determined, the method may include applying an assistive force to the user's limb based on the flexion assistance.

[0016] According to flexion assist, the application of assistive force can advantageously correct knee injuries from the hip level. In the flexion assist profile, the assistive torque at the hip or thigh can gradually increase in parallel with the increase in knee load during the gait cycle and gradually decrease with the decrease in knee load. Fine-tuning of the assistive torque at the hip joint in terms of time, duration, and amplitude advantageously achieves progressive, anticipatory correction of knee hyperextension, rather than the sudden, passive correction known in the prior art.

[0017] In conventional corrective measures for knee hyperextension, the range of motion of the knee joint is restricted directly at the knee joint by bracing or other means, or a reaction force is provided at the knee joint in response to active hyperextension. These corrective measures cause pauses or instabilities in the natural gait cycle, causing discomfort or loss of balance for the user, and also preventing the user from practicing a normal gait. In contrast to prior art methods, the assistive force applied at the hip level by the flexion assist profile according to this disclosure can correct knee hyperextension by effectively counteracting the portion of the load causing hyperextension at the knee joint, thus facilitating the restoration of the user's natural gait. The systems, methods, and apparatus of this disclosure also allow for the mixing of assist profiles for multiple joints, such that the assist at the hip level can correct gait injuries in one or all of the hip, knee, or ankle joints.

[0018] The timing of flexion assistance can be coordinated with a user's specific needs by matching the timing of flexion assistance with the determined time of knee hyperextension or with the time in the middle zone of the stance phase of the gait cycle. For example, the timing of flexion assistance can be in the range of 15% to 40% of the gait cycle, particularly 20% to 35% of the gait cycle, or more specifically 25% to 30% of the gait cycle, and can be fine-tuned according to the user's specific needs and characteristics.

[0019] The duration of flexion assistance can range from 10% to 55% of the gait cycle, particularly 20% to 35%, or more specifically 25% to 30%, and can be fine-tuned according to the user's specific needs and characteristics. The amplitude of flexion assistance can be 1.0. Up to 4.0 Within that range, especially 1.5 Up to 2.5 Within that range, or more specifically 1.75 up to 2.25 Within a certain range, and can be fine-tuned according to the user's specific needs and characteristics.

[0020] In one embodiment, the system and method may include iterative steps for determining a personalized flexion assist for a user. Advantageously, the flexion assist can be provided at a joint different from the source of the gait injury. The steps of the method may include identifying a first hyperextension of the user's knee joint during the gait cycle, determining a first time of the first flexion assist, determining a first duration of the first flexion assist, and determining a first amplitude of the first flexion assist. After the first flexion assist is determined, the method may include applying an assisting force to the user's limb (e.g., at the hip or thigh) based on the first flexion assist.

[0021] During the application of assist force based on the first flexion assist, the method may also include identifying uncorrected hyperextension of the user's knee (referred to as "second knee hyperextension," to distinguish it from initial knee hyperextension) or induced knee flexion during the standing phase of the gait cycle (meaning the flexion assist is too high), which may require fine-tuning of the assist force. If second knee hyperextension has been identified, the method may increase the amplitude of the second flexion assist relative to the first flexion assist and apply assist force to the user's limb based on the modified second flexion assist. On the other hand, if induced knee flexion has been identified during the standing phase, the method may decrease the amplitude of the second flexion assist relative to the first flexion assist and apply assist force to the user's limb based on the modified second flexion assist.

[0022] During the application of assist force based on the second flexion assist, the method may also include identifying uncorrected hyperextension of the user's knee joint (referred to as "third knee hyperextension," to distinguish it from initial knee hyperextension) or induced knee flexion during the standing phase of the gait cycle (meaning the flexion assist is too high), which may require further fine-tuning of the assist force. If third knee hyperextension has been identified, the method may include adjusting the timing of the third flexion assist relative to the first or second flexion assist and applying assist force to the user's limb based on the corrected third flexion assist. Alternatively, if induced knee flexion during the standing phase has been identified, the method may reduce the amplitude of the third flexion assist relative to the first or second flexion assist and apply assist force to the user's limb based on the corrected third flexion assist.

[0023] According to different embodiments, the method may include iteratively repeating the steps described above, for example, determining a fourth, fifth, or any other flexion assist by increasing or decreasing the amplitude of the torque profile, by adjusting the time of the flexion assist, or by adjusting the duration of the flexion assist. By iteratively detecting knee hyperextension or knee flexion during the standing phase and adjusting the amplitude, time, or duration of the flexion assist based on the detection results, the resulting personalized flexion assist can be advantageously fine-tuned according to the user's characteristics and needs.

[0024] An exemplary wearable robot for performing the method and / or forming part of the system may include an active pelvic orthosis (APO) having a drive system arranged to assist bilateral hip flexion / extension movements transmitted by first and second leg units. The APO may include a torso from which the drive system extends to at least one hip joint corresponding to at least one leg unit. The APO preferably includes a power unit and a computing unit. The power unit is preferably configured to provide auxiliary power to the drive system to drive at least one leg unit at the hip joint according to an auxiliary profile of the computing unit. The auxiliary profile may include flexion assistance for correcting knee hyperextension in the user.

[0025] The flexion assist of the auxiliary profile can be determined according to the method of this disclosure. In some embodiments, the computing unit may be configured to determine the timing, duration, and amplitude of the flexion assist of the auxiliary profile based on the identification of knee hyperextension during the standing phase. The computing unit may be connected to at least one sensor to identify knee hyperextension or knee flexion during the standing phase. The computing unit automatically determines the timing, duration, and amplitude of the flexion assist of the auxiliary profile.

[0026] With the flexion assist determined, the computational unit can be configured to control the drive system to drive at least one leg unit at the hip joint according to the assist profile (including the flexion assist).

[0027] In addition to the flexion assist according to currently disclosed methods for correcting knee hyperextension, the assist profile may include additional flexion and / or extension assists, as contemplated by those skilled in the art, to assist movement and restore functional gait patterns by providing coordinated assistance during limb movement. For example, the computing unit may be configured to determine the segmentation of a user's gait cycle and / or gait events based on input from at least one sensor, and to apply assistive forces to the user's limb by initiating a swing phase based on a first flexion assist and an assistive force for propelling a portion of the limb during the gait cycle.

[0028] The computing unit can also be configured to provide feedback to a user or clinician by actively assessing knee hyperextension using at least one sensor. In some embodiments, the computing unit may be arranged to present gait training to the user by means such as an incremental reduction in the duration and / or amplitude of flexion assistance based on feedback determined by the computing unit.

[0029] By providing improved gait assistance with increased adjustability and effectiveness, the above-described embodiments, systems, and methods address the problems of existing systems and methods for correcting knee hyperextension, including braces, walking aids, and other orthotics with limited adjustability and only responding to damage to a single joint. These and other features of this disclosure will be better understood with reference to the following description, the appended claims, and the accompanying drawings. Attached Figure Description

[0030] Figure 1 This provides an exemplary schematic diagram and corresponding chart illustrating a gait cycle that includes a standing phase and a swing phase (divided into heel strike and toe lift phases).

[0031] Figure 1A This is a diagram illustrating an exemplary hip assist profile (hAP).

[0032] Figure 2 This is an exemplary schematic diagram illustrating the gait cycle, including the standing and swinging phases, in a paralyzed limb that exhibits knee hyperextension.

[0033] Figure 3 This is a simplified diagram of hyperextension at the knee joint.

[0034] Figure 4 It is a diagram depicting the change in knee angle as the duration of the gait cycle of a user exhibiting knee hyperextension.

[0035] Figure 5 This is a simplified diagram of a method for correcting knee hyperextension according to an embodiment of the system and / or method of this disclosure.

[0036] Figure 6 This is an illustration of a user wearing a schematic wearable robot while walking, with illustrations of different possibilities for the assistive profile at different times relative to the mean and standard deviation of the hip joint angle.

[0037] Figure 7 This is a flowchart illustrating a method for correcting knee hyperextension according to an embodiment of the present disclosure.

[0038] Figure 8 It is a diagram depicting the knee angle as the duration of the gait cycle of a user whose knee hyperextension has been corrected using an embodiment of the system and / or method according to this disclosure changes.

[0039] Figure 9 This is a flowchart illustrating a method for correcting knee hyperextension according to an embodiment of the present disclosure.

[0040] Figure 10a shows a perspective view of an exemplary wearable robot arranged as an active pelvic orthosis.

[0041] Figure 10b shows a perspective view of an exemplary wearable robot arranged with an open shell for an active pelvic orthosis.

[0042] Figure 11 It is a schematic diagram that classifies different time-state damages and provides guidance for design assistance.

[0043] Figure 12 It is used according to Figure 11 A flowchart of a customized assistance adjustment procedure defined based on a specific gait impairment.

[0044] Figure 13 It is a schematic diagram of a gait cycle divided into seven sub-stages: load response, mid-stance, end-stance, pre-swing, initial swing, mid-swing, and end-swing.

[0045] Figure 14A and 14B The selection of auxiliary primitives is shown based on step 1 in the customized hip joint auxiliary profile (T-hAP) of the system and method.

[0046] Figure 15 This illustrates the identification of a biomechanical gait cycle sub-phase in a user's hip joint angle profile based on step 2 of the system and method.

[0047] Figure 16The sub-stages for identifying auxiliary primitives as the user's gait cycle according to steps 3 and 4 in the system and its method are shown, as well as time-based T-hAP shaping.

[0048] Figure 17 The method of identifying duration-based T-hAP shaping is illustrated in step 5 of the system and its method.

[0049] Figure 18 The method of identifying amplitude-based T-hAP shaping is illustrated in step 6 of the system and its method.

[0050] The accompanying drawings are not necessarily drawn to scale, but are drawn in a way that provides a better understanding of the parts, and are not intended to limit the scope but to provide illustrative examples. Detailed Implementation

[0051] Different embodiments of the invention can be better understood from the following description and accompanying drawings, in which similar reference characters may refer to similar elements.

[0052] While this disclosure is susceptible to various modifications and alternative structures, certain illustrative embodiments are shown in the accompanying drawings and will be described below. However, it should be understood that this disclosure is not intended to be limited to the disclosed embodiments, but rather is intended to cover all modifications, alternative structures, combinations, and equivalents that fall within the spirit and scope of this disclosure and are defined by the appended claims.

[0053] It should be understood that, unless the terms defined in this patent have a descriptive meaning, there is no intention, whether explicit or indirect, to limit the meaning of the term beyond its ordinary or general meaning.

[0054] According to various embodiments, systems and methods for correcting gait disorders using wearable robots or assistive lower limb exoskeletons (such as active pelvic orthotics (APO)) provide a novel assistive strategy for correcting knee hyperextension, capable of providing customized assistance based on the user's actual needs to, for example, allow for a more natural gait. Correction of knee hyperextension can be based on providing assistive forces to the user's limbs during the standing phase of the gait cycle. During the standing phase, flexion assistance can be provided at hip level, i.e., at the thigh, to counteract knee hyperextension.

[0055] While exemplary embodiments of this disclosure have been shown and described for correcting knee hyperextension by providing assistive forces to a user's limbs during the standing phase of the gait cycle, embodiments of this disclosure can also be adapted to correct various gait injuries, including standing and swing injuries. For example, the principles of systems and methods for correcting knee hyperextension based on assistive flexion torque can be applied to systems and methods for correcting knee flexion based on assistive extension torque with extension assist or contour. Furthermore, the final assist provided for different gait injuries may be a sum of different proposed assist contours, such that applying assistive torque to a single joint can address gait injuries in other joints.

[0056] As will be understood by those skilled in the art from this disclosure, embodiments of the present invention are not limited to hip exoskeletons and cannot be applied to any robotic joint that requires correction of gait phases or events, such as robotic joints associated with assistive lower limb physiological joints.

[0057] During ground walking exercises and under dynamic conditions, the APO provides hip flexion / extension torque at precise times and durations, known as the hip assist profile (hAP). Because of the ability to customize the hAP, the APO can improve one or more gait determinants for users affected by gait impairment (e.g., lower limb amputees or users with neurological disorders, such as stroke patients after a stroke).

[0058] like Figure 1A As shown, the hAP of APO is a curve of torque versus gait period, characterized by parameters (a) corresponding to amplitude (a), phase (p), and duration (d). flexion or a1, p flexion or p1, d flexion or d1, a extension or a2, p extension or p2 and d extension Or d2). These parameters define the position of two torque clocks at a specific percentage in the user's gait pattern, as well as their duration and amplitude. Similar characteristics for amplitude (a), phase (p), and duration (d) are applied to... Figure 14A , Figure 14B and Figures 16-18 .

[0059] For each user, there is a problem of determining the most effective hAP (i.e., torque and gait cycle) provided at the user's hip, with the primary objectives of: (1) mitigating the effects of gait impairment at different joints (i.e., hip, knee, and ankle); and / or (2) improving the user's functional outcomes (i.e., walking speed, stability, and symmetry). When considering neurological disorders in the population, such as stroke rehabilitation, users exhibit significant variability in residual conditions such as gait impairment, spasticity, and weakness, which complicates the ability to determine the most effective hAP for an individual.

[0060] According to this disclosure, the improved and effective role of hAP (torque-gait cycle) provided on a user's hip joint to mitigate hip, knee, ankle, and gait injuries is referred to as customized hip assist profile (T-hAP). In the embodiments, systems, and methods described herein, an improved solution is provided to allow for the identification of T-hAP for a specific user and the provision of such T-hAP to the user.

[0061] To facilitate understanding of embodiments of the disclosed systems and methods for correcting knee hyperextension, the description of some terms may be useful. The described biomechanical and anatomical terms do not deviate from their normal understanding and are readily understood by those skilled in the art of kinesiology.

[0062] Examples of systems and methods for correcting knee hyperextension can be described in conjunction with gait cycles, defined as the period and sequence of events or movements during movement from when one foot contacts the ground to when the same foot contacts the ground again. Figure 1 The figure shows a single gait cycle 100 or stride of a healthy individual, which distinguishes the time parameters of the gait cycle when the heel strikes the ground and the toes leave the ground on the left and right legs.

[0063] Each gait cycle has two phases: the stance phase 102 and the swing phase 104. The stance phase 102 is the period when the foot is in contact with the ground. The swing phase 104 is the period when the foot is not in contact with the ground. In cases where the foot never leaves the ground (drag), the swing phase 104 can be defined as the phase in which all parts of the foot are moving forward. Figure 1 As shown in the exemplary schematic diagram, the standing phase 102 typically accounts for 60% of the gait cycle 100, and the swing phase 104 typically accounts for 40% of the gait cycle 100.

[0064] The double-support phase (both feet in contact with the ground simultaneously) during the stance phase 102 of gait cycle 100 gives way to two double-float phases (neither foot in contact with the ground) at the beginning and end of the gait swing phase. The double-support phase typically accounts for 20% of the gait cycle. Single-support refers to the phase where only one foot is in contact with the ground. In walking, this corresponds to the swing phase of the other limb.

[0065] Figure 1 The heel strike 106 is shown as an event marking the initial contact phase. Initial contact comprises a brief period beginning when the foot contacts the ground and is the first phase of double support. Heel strike 106 and initial contact involve 30° hip flexion with the knee fully extended, the ankle moving from dorsiflexion to a neutral position, and then into plantar flexion. The normal range of motion for an adult knee is 0° to 135°, and full knee extension should generally not exceed 10° during a normal gait cycle.

[0066] Following this, knee flexion (5°) increases, just as plantar flexion of the heel increases. Plantar flexion is caused by eccentric contraction of the anterior tibia, and knee extension is caused by contraction of the quadriceps. Hamstring contraction leads to flexion, and rectus femoris contraction leads to hip flexion. Toe lift-off occurs when the toes make distal contact. Hip extension becomes less, and the knee is often flexed at 35-40° with the toes off the ground.

[0067] Knee hyperextension is typically characterized by an increase in full knee extension during the knee load phase of the gait cycle 100, specifically the stance phase 102. Hyperextension can be classified as mild, moderate, or severe depending on the importance of associated ligament defects, quadriceps atrophy or weakness, ankle flexion spasm, Achilles tendon contracture, gastrocnemius-plantar muscle weakness, symptomatic patellofemoral arthritis, etc.

[0068] Figure 2 An example of knee hyperextension in a paralyzed limb (such as a limb with mild or partial paralysis) is shown during gait cycle 200. During heel strike 206 (or initial contact) in the standing phase 202, as... Figure 3 As shown, knee instability causes the knee joint to "bounce" backward under the load L when weight is transferred forward onto the limb (especially onto the knee joint 310 of the limb), entering a state of hyperextension. Hyperextension 312 of knee joint 310 may include a range of knee extension from 10° to 20° or greater, and may continue from heel strike 206 to toe lift 208, or until knee flexion in swing phase 204 restores the knee joint to an extension of no more than 10°.

[0069] Figure 4An illustration is shown depicting the knee extension / flexion angle as the duration of gait cycle 400 varies in a patient with a paralyzed side, resulting in knee hyperextension during the standing phase of the paralyzed limb. As shown, the patient's knee hyperextension 412 begins between 25% and 30% of the gait cycle, resulting in knee extension approaching 15°.

[0070] Embodiments of systems and methods for correcting knee hyperextension are described herein to provide customized assistance according to the user's needs. Embodiments of systems and related methods for correcting knee hyperextension according to this disclosure advantageously achieve a more natural gait by providing assistive forces to the user's limb at hip level during the standing phase of the gait cycle to counteract knee hyperextension, and, as those skilled in the art will understand from this disclosure, the same principles apply to correcting gait injuries in other joints.

[0071] exist Figure 5 The simplified diagram illustrates an embodiment of a method for mitigating or correcting knee hyperextension in a user. In this method, a force F is applied to counteract knee hyperextension as a load L moves forward onto the knee joint 510 of the limb. This force F prevents hyperextension of the knee joint 510 between the hip joint 514 and the ankle joint 516. The force F can be generated by providing an auxiliary flexion torque at the hip joint 514 via the thigh connection during the standing phase, and can increase and decrease with variations in the load applied to the knee joint 510 during the standing phase. This auxiliary torque forms a flexion assist in the assist profile. Although the auxiliary torque does not match the bio-torque of the assisted joint (i.e., the hip joint), the auxiliary torque can be tailored to correct gait impairments of the knee joint, thereby reducing the need for additional sensors and systems for correcting the user's gait.

[0072] Figure 6 An example of the auxiliary profile 600 is shown, illustrating the relationship between the auxiliary assistance and the % gait cycle. As illustrated, the flexion assistance 620 can be characterized by time 622, duration 624, and amplitude 626. Time 622 can be defined as the % gait cycle at half the duration of the flexion assistance 620. Duration 624 can be defined as the % gait cycle from the initial application of the auxiliary torque to the end of the application of the auxiliary torque. Amplitude 626 can be defined as the maximum value of the auxiliary torque 620.

[0073] The flexion assist 620 can have a symmetrical bell or Gaussian shape, wherein amplitude 626 defines the height of the curve peak, time 622 defines the location of the peak center, and duration 624 defines the width of the curve. Advantageously, the flexion assist can be increased and decreased at varying rates as the gait cycle progresses, thereby allowing the assist torque to follow the natural contour of the knee joint load.

[0074] According to some embodiments, the shape and slope of the buckling assist profile can be configured to vary depending on the user's different characteristics and needs or the capabilities of the assist torque generating device. For example, the buckling assist profile may be asymmetrical, with a leftward or rightward tilt or skew, so that the timing and amplitude of buckling assist occur at different points along the gait cycle. Depending on the user's needs and the capabilities of the assist torque generating device, the slope on one side of the buckling assist profile may be constant, so that the rate of increase or decrease in assist torque can vary at different times or remain constant. For example, the buckling assist profile may form a bending peak, a triangular peak, or another variation with a peak or local maximum.

[0075] According to Figure 7 In an embodiment of the method, method 700 may include identifying hyperextension of the user's knee joint during a gait cycle 750 and determining flexion assistance parameters 760 based on the identified hyperextension of the user's knee joint, the parameters including the duration of flexion assistance, the duration of flexion assistance, and the initial amplitude of flexion assistance.

[0076] The timing of flexion assistance can be tailored to a user's specific needs by matching the timing of flexion assistance with the determined time of knee hyperextension or the time in the middle region of the stance phase of the gait cycle. For example, the timing of flexion assistance can be in the range of 15% to 40% of the gait cycle, particularly 20% to 35%, or more specifically 25% to 30%, and can be fine-tuned according to the user's specific needs and characteristics.

[0077] The duration of flexion assistance can range from 10% to 55% of the gait cycle, particularly 20% to 35%, or more specifically, 25% to 30%, and can be fine-tuned according to the user's specific needs and characteristics. For example, the duration of flexion assistance can be adjusted based on a clinical assessment of spasticity or weakness in the paralyzed limb during the standing phase; the more spastic the limb is characterized by spastic contractions, the smoother, gentler, and longer the flexion assistance should be to avoid inducing spastic contractions.

[0078] The amplitude of the flexion assist can be 1.0. ~3.0 Within the range, especially at 1.5 ~2.5 Within that range, or more specifically within 1.75 ~2.25 Within a certain range, and can be fine-tuned to meet the specific needs and characteristics of the user (e.g., by applying pressure to the user). (Flexion assist in units of / kg). In one example, the amplitude of the flexion assist can be adjusted based on the severity of knee hyperextension (i.e., severe, moderate, or mild) and the user's weight. The amplitude can be iterative or real-time, determined based on average or normal gait speed, or it can be adjusted based on the user's gait speed, the severity of knee hyperextension, and weight.

[0079] After determining the flexion assist 760, the method may include applying an assisting torque 770 to the user's limb based on the determined flexion assist to correct hyperextension. The corrected gait cycle may be reassessed to identify any remaining knee hyperextension or irregularities 780, such as irregular knee flexion during the standing phase. As Figure 9 As described in the embodiments, the timing, amplitude, or duration of flexion assistance can be adjusted in fine-tuning step 790 to minimize any remaining knee hyperextension or irregularity.

[0080] While known hip orthoses provide flexion torque during the swing phase and extension torque during the standing phase, thus replicating the physiological torque pattern of the hip joint, the flexion assistance of this disclosure can be applied by a hip orthoses to provide hip flexion torque during the standing phase (which corresponds to the extension phase of the hip joint). It has now been found that embodiments of this disclosure alleviate knee hyperextension by providing torque at the hip level (and therefore not directly acting on the joint exhibiting pathological symptoms). Prior to this disclosure, it was considered impossible to correct specific knee pathological symptoms by acting on the hip joint. Advantageously, embodiments of this disclosure allow for correction of gait injuries from a single location, such as knee hyperextension correction from the hip, increasing ease of use and reducing the number and extent of sensors, actuators, braces, etc., required for gait correction.

[0081] exist Figure 8 Some advantages of the described method are illustrated, with a diagram depicting the knee angle as a function of the duration of gait cycle 80° for a user undergoing correction of knee hyperextension, according to an embodiment of the system and / or method of this disclosure. In this example, according to the use of Figure 7 The method of this disclosure shown determines the buckling assist and directs it toward Figure 4 To provide assistance to users.

[0082] Figure 8 An example of knee flexion / extension during a gait cycle of 800 in a patient with a paralyzed side is shown, wherein an assistive force with flexion assistance is applied according to the method of this disclosure. Figure 4In contrast to the unassisted gait cycle 400 which exhibits hyperextension 412, the flexion-assisted gait cycle 800 according to this disclosure results in normal physiological extension 818 of the knee joint, approximately 5°, during the standing phase of the paralyzed limb, thus demonstrating that knee hyperextension has been corrected and the user's natural gait has been restored.

[0083] According to Figure 9 In one embodiment, the method of this disclosure may include an iterative step for fine-tuning steps (e.g., ... Figure 7 During the fine-tuning step 790), a personalized buckling assist is determined for the user. For example... Figure 7 As shown in method 700, method 900 may similarly include identifying a first hyperextension of the user's knee during a gait cycle 750, determining a first time of first flexion assistance, determining a first duration of the first flexion assistance, and determining a first amplitude of the first flexion assistance. After determining the first flexion assistance 760, the method may include applying an assistive force to the user's limb based on the first flexion assistance 770.

[0084] During the application of assistive force based on the first flexion assist, the method may further include identifying a second hyperextension or first knee flexion 780, 980 of the user's knee during the standing phase of the gait cycle, and, for example, possibly requiring fine-tuning of the assistive force. Second knee hyperextension is identified. The method may include increasing the magnitude of the second flexion assist 982 relative to the first flexion assist and applying assistive force to the user's limb based on the modified second flexion assist. First knee flexion is identified during the standing phase. The method may reduce the magnitude of the second flexion assist 986 relative to the first flexion assist and apply assistive force to the user's limb based on the modified second flexion assist.

[0085] During the application of assistive force based on a second flexion assist, the method may further include identifying a third hyperextension or second knee flexion of the user's knee during the standing phase of the gait cycle 980. Third knee hyperextension is identified. The method may include adjusting the timing of the third flexion assist relative to the first or second flexion assist 984, and applying assistive force to the user's limb based on the modified third flexion assist. Second knee flexion is identified during the standing phase. The method may include reducing the amplitude of the third flexion assist relative to the first or second flexion assist 988, and applying assistive force to the user's limb based on the modified third flexion assist.

[0086] According to different embodiments, the method may include iteratively repeating the above steps, for example, determining a fourth, fifth, or any other flexion assist by increasing or decreasing the amplitude of the flexion torque, by adjusting the time of the flexion assist, and / or by adjusting the duration of the flexion assist. By iteratively detecting knee hyperextension or knee flexion during the standing phase and adjusting the amplitude, time, and / or duration of the flexion assist based on the detection results, the resulting personalized flexion assist can be advantageously fine-tuned to suit the user's characteristics and needs.

[0087] Although described in the preceding embodiments as an iterative process with successive steps, the methods of this disclosure can be applied in real time to determine a second, third, fourth, fifth, or any other flexion assist by increasing or decreasing the amplitude of the flexion assist, by adjusting the timing of the flexion assist, and / or by adjusting the duration of the flexion assist within a single gait cycle, in order to correct the assist profile. For example, a knee joint sensor can be provided to obtain real-time measurements of the knee joint, allowing for real-time fine-tuning or adjustment of the applied flexion assist within the gait cycle without asynchronous observation and correction.

[0088] As shown in Figures 10a and 10b, an exemplary system for correcting knee hyperextension according to this disclosure may include a wearable robot or robotic exoskeleton, such as an active pelvic orthosis (APO) 1000, which has a drive system arranged to assist bilateral hip flexion / extension movements transmitted by first and second leg units 1400. An exemplary APO can be found in U.S. Patent Application Publication 2017 / 0367919, published December 28, 2017, which is incorporated herein by reference. The APO 1000 may include a torso 1100 from which a drive mechanism 1200 of the drive system extends to first and second hip joints 1300, each having at least one sensor 1320, and the first and second hip joints 1300 corresponding to the first and second leg units 1400, respectively.

[0089] The APO 1000 comprises at least a torso 1100, first and second hip joints 1300, and first and second leg units 1400 forming a wearable frame. The method of securing the APO to the user's torso and / or waist and the user's legs can be a common, conventional form of APO, including belts, cuffs, straps, and other auxiliary fixation elements common in orthotics. An example interface of an APO is described in U.S. Patent 11,000,439, issued May 11, 2021, which is incorporated herein by reference and is not intended to be limiting of this disclosure.

[0090] In one embodiment, at least one sensor 1320 may include an encoder arranged to measure hip flexion / extension angles of the first and second leg units 1400 relative to the torso 1100 at the first and second hip joints 1300. Alternative sensor arrangements are also contemplated, including onboard sensors connected to the computing unit 1140, offboard sensors (pressure sensors in shoes or treadmills, optical sensors, gait analysis labs), etc., as understood by those skilled in the art, for assessing gait or identifying knee hyperextension.

[0091] The APO preferably includes a power supply unit 1120 and a computing unit 1140, such as a battery and a processor or system-on-a-module control board, respectively. According to one embodiment, the power supply unit 1120 and the computing unit 1140 may be housed within the torso 1100 of the APO. According to different embodiments, the torso 1100 may be attached to a waist belt to accommodate a user, and the first and second leg units 1400 may each be attached to limb straps or linkages to transmit mechanical power to the user's limbs.

[0092] The power supply unit 1120 is preferably arranged to provide auxiliary power to the drive unit 1200 for driving the transmission units 1420 of the first and second leg units 1400 at the first and second hip joints 1300 according to an auxiliary profile provided by the computing unit 1140. This auxiliary profile may include a flexion assist for correcting knee hyperextension in the user, which may be determined by the computing unit 1140 based on input signals provided by at least the sensors 1320 or a clinician.

[0093] Flexion assistance of the assist profile can be determined according to the method of this disclosure. In some embodiments, the computing unit 1140 may be connected to at least one sensor 1132 to identify hyperextension or flexion of the knee joint during the standing phase, and the computing unit 1140 automatically determines the time for flexion assistance, the duration of flexion assistance, and the amplitude of flexion assistance for the assist mode. After determining the flexion torque, the computing unit 1140 may be configured to control the drive device 1200 to drive at least one leg unit 1400 at the hip joint 1300 according to the assist profile including flexion assistance.

[0094] The computing unit 1140 can be configured to iteratively or continuously monitor a user's gait cycle to dynamically adjust flexion assistance according to the user's needs. In different embodiments, the user's gait cycle can be assessed and / or iteratively reassessed by a clinician, such as in a gait analysis laboratory. The clinician can then provide the computing unit 1140 with an assistance profile including flexion assistance based on the disclosed flexion assistance.

[0095] The assist profiles of this disclosure are not limited to flexion assist for correcting knee hyperextension, and may include additional flexion and / or extension assist as contemplated by those skilled in the art. The methods and apparatus of this disclosure may allow assistance to multiple joints from a single location (such as the hip joint), such that assistance at the hip joint level may correct gait impairment at one or all of the hip, knee, or ankle joints.

[0096] According to this disclosure, in addition to flexion-assisted correction of knee hyperextension, the additional flexion and / or extension assistance of the assist profile can be configured to assist movement and restore functional gait patterns by providing coordinated assistance during limb movement within the gait cycle. For example, computing unit 1140 can be configured to determine the segmentation of the user's gait cycle and / or gait events based on input from at least one sensor 1132, and to apply assistive forces to the user's limbs based on a first flexion assist and assistive forces for propelling portions of the limbs during the gait cycle (such as by initiating a swing phase).

[0097] exist Figure 11-12 This document illustrates guidance on designing aids for asynchronous injuries using the disclosed methods and devices for correcting knee hyperextension. Figure 11 In this study, gait injuries are classified according to (i) the swing / standing phase and (ii) the anatomical joint in which the gait injury occurs. Each box represents a type of gait injury, where the clinical name of the gait injury is followed by the torque (extension torque for hip extension and knee flexion defects; flexion torque for the remaining injury) and one or more sub-phases in which the torque should be applied to the hip joint. Figure 12 A block diagram is provided illustrating a customized gait assistance adjustment procedure defined based on a specific gait impairment, which can reflect... Figure 7 and Figure 9 Methods to address knee hyperextension. Figure 13 The seven sub-phases of the gait cycle are shown: as in Figure 11 The load response, mid-stage standing, end-stage standing, pre-oscillation, initial oscillation, mid-stage oscillation, and end-stage oscillation mentioned in the text.

[0098] Case Scenario

[0099] In clinics, physical therapists use APOs to treat stroke patients. Clinically, the intended use of APOs is to reduce gait damage in the hip, knee, and ankle joints, ultimately improving functional outcomes such as gait speed and symmetry. The challenge for physical therapists is determining which movements the APO should provide, such as the torque delivered to the hip via the APO, to achieve positive results.

[0100] An APO can communicate with a physical therapist using terminology and concepts familiar to clinicians. The following methods can be used to determine the appropriate parameters for use with an APO:

[0101] A. Identify the user's gait impairment (through instrumental gait analysis or visual analysis) and the degree of spasticity and weakness in different muscles. This data may include gait impairment, strength level, spasticity level, and body weight.

[0102] B. Ask the user to (i) wear the APO and (ii) perform 2-3 walks in the transparent mode "TM" (i.e., the APO is unassisted and unresisted) to determine the baseline operation of the APO and the hip angle profile.

[0103] C. Use data as input to a specific routine that automatically extracts T-hAP from the data for the user.

[0104] D. Provide the APO with the recommended T-hAP to train the user to walk better.

[0105] An overview of the system and method is provided. First, a list of gait impairments is input. This leads to Step 1, which involves selecting auxiliary primitives on the "Gait Impairment & Assistance" taxonomy. The internal output 1 of Step 1 generates a list of auxiliary primitives based on the user's gait impairments.

[0106] like Figure 12 As shown, standing-related injuries may include defects in hip extension, hip abduction, knee flexion, knee hyperextension, and plantar flexion. When considering the standing phase, it's important to assess muscle weakness and spasticity or laxity during this phase. Swing-related injuries may include defects in hip flexion, hip elevation, circumduction, knee flexion, knee stiffness, foot drop, or clubfoot. Similarly, assessments for muscle weakness and spasticity / laxity are necessary during the swing phase.

[0107] Reference Figure 14A and 14B The auxiliary primitives are determined based on gait impairment. For example, in Figure 14A In this context, the first auxiliary unit 1 for hip abduction defects may cause the APO to be adjusted to accommodate a greater extension torque (a2), particularly at the mid-stance center of the user's gait cycle sub-phase, as demonstrated by the percentage of the gait cycle.

[0108] exist Figure 14B In the second auxiliary unit of gait injury in stiff knee joints, the APO action can be set to provide greater flexion torque (a1) in the user's gait cycle sub-phase, from the forward rocking to the backward rocking phase, as demonstrated by the percentage of the gait cycle.

[0109] like Figure 11 As shown, the following list outlines the guidelines for adjusting APO based on the following gait impairment and assistance classifications.

[0110] For standing injuries:

[0111] Defects in hip extension result in extension torque, accompanied by a mid-stance load response (LRMSint).

[0112] Defects in hip abduction result in extension torque, accompanied by a load response at the mid-stance center (MSc).

[0113] Knee flexion or hyperflexion and defects in knee extension result in extension torque at the midpoint of the standing position (MSc).

[0114] Knee hyperextension or defects in the knee stabilizer can lead to flexion torque during the standing phase, where hyperextension occurs.

[0115] For the ankle joint, a deficiency in plantar flexion results in flexion torque at the pre-swing center (PSc).

[0116] For swing injuries:

[0117] A defect in hip flexion occurs when the hip flexor muscles are weak, resulting in flexion torque at the pre-swing center (PSc).

[0118] Hip elevation occurs during contralateral hip adduction compensation, resulting in flexion torque at the early pre-swing crossover point (PSESint).

[0119] Circumduction or hip abduction compensation results in flexion torque at the early pre-swing crossover point (PSESint).

[0120] Defects in knee flexion result in flexion torque at the early swing center (Esc).

[0121] Stiffness results in buckling torque at the pre-swing-end swing intersection (PSLSint).

[0122] Reduced foot gap (such as defects in foot drop or dorsiflexion) results in buckling torque at the early swing center (ESc)x.

[0123] Next, the hAP is provided by the APO's TM. Step 2 includes identifying the biomechanical gait cycle sub-stage in the user's TM's hAP. Step 2 generates the user's internal output 2 of the hAP, which is divided into seven gait cycle sub-stages.

[0124] For example, Figure 15The relationship between gait cycle and hip angle (degrees) is shown. In this example, the mean and standard deviation of the angular profile of short-distance walking in TM are plotted along with the data to determine the biomechanical gait cycle as a function of the TM hip angle profile. In the example shown, the following information was obtained: Stand Phase Duration (StPD): 54%; Swing Phase Duration (SwPD): 46%; Load Response-Mid-Stand Crossover (LRMSint): 10%; Mid-Stand Center (MSc): 22%; Pre-Swing Center (PSc): 59%; Pre-Swing Early Swing Crossover (PSESint): 64%; Early Swing Center (ESc): 70%; Pre-Swing-End Swing Crossover (PSLSint): 77%.

[0125] From the hAP perspective, step 3 includes adapting, transforming, and / or re-adapting the auxiliary primitive list obtained in step 1 to the user's gait cycle sub-stages. Step 3 produces an internal output 3 of the auxiliary primitive list represented by the user's gait cycle sub-stages. Figure 16 Examples 1 and 2 related to output 3 are shown. In Example 1, the auxiliary primitive of step 1 for a gait injury with a known head-down, feet-up (i.e., hip abduction defect) and the APO effect of extension torque in the MSC of the user's gait cycle sub-phase are used, with data from step 2 used to identify this extension torque as being at 22% of the gait cycle. In Example 2, the auxiliary primitive of step 1 for a gait injury with a known knee stiffness and the APO effect of flexion torque in the PSLSint of the user's gait cycle sub-phase are used, with data from step 2 used to identify this flexion torque at 77% of the gait cycle.

[0126] Step 4 involves combining the auxiliary primitive with the internal output 4 of T-hAP, defined in units of time (t). Figure 16 An example is given of combining auxiliary primitives by weighted sum of gait damage from buckling torque and extension torque obtained from step 3, thereby creating a time-defined T-hAP output, and combining Example 1 and Example 2 of step 3 into output 4.

[0127] Regarding the level of spasticity, step 5 involves shaping the T-hAP based on duration and generating an internal output 5 described by time (t) and duration (d). The duration of the assist torque is determined based on a clinical assessment of spasticity or laxity of the paralyzed limb during the standing / swinging phase. The more spastic contraction characterizing the limb, the smoother and gentler the hip assist should be to avoid inducing spastic contraction (i.e., the longer the duration of assist should be). Conversely, if the limb is characterized by laxity, the duration will be shorter.

[0128] according to Figure 17Referring to Examples 1 and 2, in step 2, it is determined that spasm exists during the standing phase and also during the swinging phase. Therefore, since the total duration of the Gaussian function is determined for both the standing and swinging phases, the standing phase duration (StPD) is determined to be 54%, while the swinging phase duration is determined to be 46%. Figure 17 The T-hAP is shown based on the timing from step 4 and the duration from step 5.

[0129] Regarding the intensity level corresponding to the user's weight, step 6 includes shaping the T-hAP based on amplitude and obtaining the internal output 6 of the T-hAP. Amplitude is determined based on body mass and degree of muscle weakness. For stroke patients, muscle strength should be considered in addition to the user's body mass.

[0130] When determining the amplitude, muscle weakness during the standing and swinging phases is determined based on thresholds related to body mass. Figure 18 In the example shown, the first threshold 1 is determined to be 10% of body mass, and muscle weakness is present. The second threshold is 8% of body mass, and no muscle weakness is present. The amplitudes of the first and second amplitudes (a1, a2) are both determined to be 5.6. .

[0131] When establishing guidelines for the combination of auxiliary primitives, the time for providing the combination of auxiliary primitives for buckling torque is limited as follows: the total number of gait injuries requiring buckling torque for each sub-stage should be taken into account, and the weighted sum should be calculated as follows: , where N i Let be the index of the gait injury requiring flexion assistance in the i-th sub-stage, and i = 1, ..., 7, representing the respective sub-stages from load response (i = 1) to end swing (i = 7). Due to the effect of weighted summation, the timing at which the assist element combination provides flexion torque may, for example, be more consistent with the earlier swing sub-stages.

[0132] Similarly, the time for the auxiliary element combination to provide extension torque is limited as follows, taking into account the total number of gait injuries requiring extension torque in each sub-stage, and the weighted sum is calculated as follows: , where N i Let be the sequence number of the gait injury requiring extension assistance in the i-th sub-stage, and i = 1, ..., 7, representing the various sub-stages from load response (i = 1) to end swing (i = 7). Due to the effect of weighted summation, the timing at which the auxiliary primitive combination provides extension torque may, for example, be more consistent with the mid-stance sub-stage.

[0133] Knee hyperextension is treated separately because physical therapists can preferably determine its timing. The extension torque provided by the combination of the knee hyperextension unit and other auxiliary units is not treated using a weighted sum, but rather addressed through prioritization.

[0134] It should be understood that not all objectives or advantages need to be achieved under any embodiment or method of this disclosure. Those skilled in the art will recognize that the disclosed wearable robots, systems, and methods can be embodied or implemented to achieve or optimize one or more of the advantages taught herein without needing to achieve other objectives or advantages taught or suggested herein.

[0135] Those skilled in the art will recognize the substitutability of the various features and methods disclosed. In addition to the described variations, those skilled in the art can mix and match other known equivalents of each feature and method to construct wearable robots in accordance with the principles of this disclosure. It will be understood by those skilled in the art that the described features can be applied to other types of orthotics, prostheses, or medical devices.

Claims

1. A system for using an assistive lower limb exoskeleton to reduce or correct knee hyperextension in a user, characterized in that, The auxiliary lower limb exoskeleton includes: A wearable frame having a torso from which a drive system for flexion / extension movements of bilateral hips extends, the drive system including drive devices connected to first and second hip joints, the first and second hip joints having at least one sensor connected to first and second leg units; The system for reducing or correcting knee hyperextension is configured as follows: (a) Identify the first hyperextension of the user's knee joint during the standing phase of the gait cycle; (b) The first flexion assist of the assist profile is determined based on the first hyperextension of the knee joint in the following manner: (i) Determine the timing of the first buckling assistance; (ii) Determine the duration of the first buckling assistance; and (iii) Determine the amplitude of the first buckling aid; (c) In accordance with the first flexion assist of the assist profile, during the standing phase, an assist flexion torque is applied to the user's limb via the assist lower limb exoskeleton; The auxiliary lower limb exoskeleton includes a power supply unit and a controller. The power supply unit is arranged to provide auxiliary power to the drive device to drive the transmission units of the first and second leg units at the first and second hip joints via the controller based on the auxiliary profile determined by the controller according to the input signals provided by the at least one sensor. The at least one sensor is arranged to determine at least one gait parameter; The controller is configured to determine the amplitude, duration, and time based on the at least one gait parameter; The controller is configured to drive the drive system at least during the standing phase based on the amplitude, duration, and time of knee hyperextension of the at least one limb.

2. The system according to claim 1, characterized in that, The system is also configured to: (d) During the standing phase in step (c), identify the second hyperextension or first flexion of the user's knee joint; (e) Adjust the first flexion assist based on identifying the second hyperextension or the first flexion of the knee joint to determine the second flexion assist; (f) Applying an assistive flexion torque to the user’s limb during the standing phase, according to the second flexion assist.

3. The system according to claim 2, characterized in that, Adjusting the first flexion assist to determine the second flexion assist based on the identification of the second hyperextension or the first flexion in the knee joint includes: increasing the amplitude of the second flexion assist relative to the first flexion assist in response to the identification of the second hyperextension in the knee joint.

4. The system according to claim 2, characterized in that, Adjusting the first flexion assist to determine the second flexion assist based on the identification of the second hyperextension or the first flexion in the knee joint includes: increasing or decreasing the duration of the second flexion assist relative to the first flexion assist in response to the identification of the second hyperextension in the knee joint.

5. The system according to claim 2, characterized in that, Adjusting the first flexion assist to determine the second flexion assist based on the identification of the second hyperextension or the first flexion in the knee joint includes: reducing the magnitude of the second flexion assist relative to the first flexion assist in response to the identification of the first flexion in the knee joint.

6. The system according to claim 1, characterized in that, The duration of the first flexion assistance is within 15% to 40% of the gait cycle, and / or the amplitude of the first flexion assistance is 1.

0. ~3.0 Within the range.

7. The system according to claim 1, characterized in that, The duration of the first flexion assist coincides with the peak velocity of the gait cycle.

8. The system according to claim 1, characterized in that, The assistive flexion torque is configured to be applied to the user's limb above the knee joint.

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