Gait event-driven time-phased, multimodal foot rehabilitation system and usage method

Abstract

The present invention provides a gait event-driven, time-phased, multimodal foot rehabilitation system and method of use. The system includes: a pressure sensor module that measures the pressure distribution value of the sole of the foot in real time; a microcontroller module that compares the measured pressure value with a preset threshold value to identify different gait events in dynamic gait and the pressure balance on the inside and outside of the sole of the foot, and controls the corresponding operations in real time; a neuromuscular electrical stimulation module that implements or stops suprathreshold electrical stimulation of target muscles in the foot based on the identified gait events; a pneumatic musculoskeletal complex module that includes pneumatic muscles and deflates or inflates the pneumatic muscles based on the identified gait events; and a vibration biofeedback module that provides biofeedback to correct the force balance of the sole of the foot when the pressure imbalance on the inside and outside of the sole of the foot is identified. Gait events include heel strike, heel lift-off, and foot lift-off. The present invention can correct foot drop and foot inversion, improve muscle compensation and atrophy, and reshape normal gait.

Description

Technical Field

[0001] The present invention relates to the field of auxiliary medical rehabilitation training equipment, and in particular to a rehabilitation system driven by gait events, which provides dynamic foot assistance in different gait phases by neuromuscular electrical stimulation, pneumatic musculoskeletal complex and sensory biofeedback in different combinations (i.e., multimodality), so as to correct foot drop, foot inversion and muscle compensation problems in users with lower limb motor function impairment (such as stroke and spinal cord injury). Background Art

[0002] For users with lower limb motor impairment, especially those with hemiplegia caused by stroke, gait impairments include bilateral imbalance, foot drop (inability to lift the forefoot), and inversion (foot rolling inward). This significantly increases the risk of falls and the difficulty of recovery. Furthermore, long-term gait impairments lead to abnormal muscle compensatory movements, making it difficult to effectively coordinate rehabilitation training for the affected lower limb muscles.

[0003] Conventional auxiliary medical equipment (see, for example, Figure 1 Ankle-foot orthosis (AFOO) is a passive orthosis with a fixed joint angle, which provides constant mechanical support and fixation to prevent foot drop and inversion. However, this type of orthosis cannot help users exercise the target muscles of the affected ankle joint. Excessive use may lead to the risk of muscle atrophy and affect the stability of the ankle joint.

[0004] In addition, existing robots for lower limb rehabilitation provide a single mechanical external force to assist during gait, leading the affected limb to complete a specified gait (such as a specific trajectory). During this process, even if the joint movement generated by the user's own muscle force is inconsistent with the robot's set gait, it will be forcibly led by the robot's motor, resulting in non-autonomous passive movement. This type of robot assistance method cannot guide the user on how to use the target muscles to correctly exert force and complete the corresponding movements during exercise, nor can it provide timely feedback signals during exercise to allow the user to realize the error and correct it, resulting in the user's muscle compensatory problems in dynamic gait cannot be corrected, and the normal gait cannot be effectively reshaped (that is, without system assistance, the user can resume normal walking).

[0005] Among existing mechanical and control designs for lower limb rehabilitation robots, there are no wearable rehabilitation systems that can simultaneously correct foot drop and inversion caused by muscle atrophy and compensatory muscle movements during dynamic walking, or provide corrective feedback. Traditional rigid exoskeleton robots for lower limb rehabilitation have overly simplistic ankle joint designs, providing single mechanical torque support and drive during different gait phases. Typically, a single degree of freedom motor rotates to achieve sagittal plane dorsiflexion (ankle flexion, with the toes moving upward toward the shin) and plantar flexion (ankle extension, with the toes straightening and pressing downward away from the shin). While these designs can offset foot drop with external force provided by the motor, they cannot correct the user's inherent muscle atrophy and compensatory movements, and they neglect to control and correct foot inversion, a common condition after stroke. This mechanical assistance approach can even cause corresponding muscle atrophy due to the lack of horizontal degrees of freedom. Furthermore, the weight of a rigid exoskeleton can easily cause a unilateral user to lose balance while walking, especially for hemiplegic users after a stroke. A musculoskeletal system combining pneumatic muscles (operated by filling air bladders with pressurized air) with an exoskeleton (a rigid external skeletal structure that protects a living organism's soft internal organs) is lighter and more flexible than traditional rigid exoskeletons. It is suitable for unilateral wear on the affected lower limb and can provide adequate mechanical assistance.

[0006] Neuromuscular electrical stimulation (NMS) can correct foot drop during the swing phase of gait by inducing calf muscle contraction through transcutaneous stimulation. Simultaneously, multi-channel NMS can correct muscle compensation. However, currently, single-channel NMS technology cannot correct foot inversion during the stance phase. Sensors sense the balance of force applied to the plantar surface at the start of the stance or swing phase, providing the user with immediate sensory feedback such as vibration, sound, light, or temperature. Users can then adjust the plantar force distribution to achieve a desired balance range and correct foot inversion. However, single-channel plantar sensory balance feedback cannot simultaneously address both foot drop and muscle compensation throughout the entire gait phase. The present invention, through a unique multimodal mechanical and electronic design, coupled with an innovative time-phased, gait-event-driven control algorithm, integrates multi-channel NMS, pneumatic musculoskeletal integration, and plantar sensory biofeedback, utilizing these elements for coordinated implementation across all gait phases. The realized rehabilitation system can be used to correct foot drop and foot inversion problems simultaneously, and can provide real-time feedback signals to enable the user to correct the deviation autonomously. It can also improve the coordination ability of the lower limb muscles and improve muscle compensation and atrophy. Summary of the Invention

[0007] As mentioned above, existing foot and ankle rehabilitation systems are not able to simultaneously correct foot drop and foot inversion in real time while walking, and also improve muscle compensation and muscle atrophy. Specifically, various existing foot and ankle rehabilitation systems have the following problems:

[0008] 1) Traditional ankle-foot orthosis: It fixes the entire ankle joint passively to prevent foot drop and inversion, but this can cause muscle atrophy and joint degeneration, making it impossible to restore a normal gait.

[0009] 2) Lower limb rehabilitation robots: The ankle design is overly simplistic, providing single mechanical torque support and drive during different gait phases. Typically, a single-degree-of-freedom motor rotates to achieve dorsiflexion and plantar flexion of the foot in the sagittal plane. This cannot simultaneously correct foot drop and foot inversion.

[0010] 3) Neuromuscular electrical stimulation: Currently, single neuromuscular electrical stimulation technology cannot be used to correct the problem of foot inversion during the stance phase of gait.

[0011] To address these issues, the present invention provides a gait event-driven, time-limited, multimodal foot control and feedback rehabilitation system. This lightweight system facilitates unilateral use (e.g., for hemiplegic patients) without compromising bilateral balance. Furthermore, compared to traditional lower limb rehabilitation robots, it is less expensive and offers superior rehabilitation results.

[0012] In a first embodiment of the present invention, a gait event-driven, time-phased, multimodal foot rehabilitation system is provided, the system comprising:

[0013] A pressure sensor module is connected to the sole of the user's foot and measures the pressure distribution values ​​of different areas of the sole of the foot in real time;

[0014] a microcontrol module that receives the measured pressure value, compares the measured pressure value with a preset threshold value to identify different gait events and pressure balance between the inner and outer sides of the sole during dynamic gait, and controls the neuromuscular electrical stimulation module, the pneumatic musculoskeletal complex module, and / or the vibration biofeedback module in real time to perform corresponding operations;

[0015] a neuromuscular electrical stimulation module configured to initiate or stop suprathreshold electrical stimulation of target muscles of the foot based on gait events recognized by the microcontroller module;

[0016] a pneumatic musculoskeletal complex module, the pneumatic musculoskeletal complex module including a musculoskeletal complex for providing mechanical support to the foot, and configured to deflate or inflate pneumatic muscles of the musculoskeletal complex based on gait events identified by the microcontroller module to secure the foot and ankle during the stance phase or to relax the foot and ankle during the swing phase of the gait cycle; and

[0017] a vibration biofeedback module configured to provide biofeedback to correct the force balance of the user's sole when the microcontroller module identifies an imbalance in the pressure between the inner and outer sides of the sole.

[0018] Gait events include heel strike, heel lift-off, and foot lift-off.

[0019] The pressure sensor module may include a first pressure sensor placed at a first metatarsal head on the sole of the foot, a second pressure sensor placed at a fifth metatarsal head on the sole of the foot, and a third pressure sensor placed at the heel.

[0020] The microcontroller module can identify gait events to achieve real-time control by:

[0021]

[0022] Among them, E is the real-time recognition of gait events, FSR1(t), FSR5(t), FSR 脚跟 (t) are the real-time pressure data measured by the first pressure sensor, the second pressure sensor, and the third pressure sensor, T1, T5, T 脚跟 They are respectively the preset thresholds of the first pressure sensor, the second pressure sensor, and the third pressure sensor.

[0023] When the pressure value measured by the third pressure sensor is less than the preset threshold, the microcontroller module can identify the gait event as heel-off, control the pneumatic muscles to deflate and stop mechanical support, and at the same time control the neuromuscular electrical stimulation module to perform suprathreshold electrical stimulation on the target muscles.

[0024] When the first pressure sensor, the second pressure sensor and the third pressure sensor are all less than or equal to their respective preset thresholds, the microcontrol module can identify the gait event as the foot leaving the ground, control the inflation of the pneumatic muscles, and at the same time control the neuromuscular electrical stimulation module to perform suprathreshold electrical stimulation on the target muscles.

[0025] While implementing suprathreshold electrical stimulation, the vibration biofeedback module can provide biofeedback to correct the force balance of the user's sole.

[0026] When the pressure value measured by the third pressure sensor is greater than a preset threshold, the microcontrol module can identify the gait event as a heel strike, control the neuromuscular electrical stimulation module to stop suprathreshold electrical stimulation of the target muscle, and control the vibration biofeedback module to stop biofeedback.

[0027] The neuromuscular electrical stimulation module may include a stimulation generator and an electrode array. The electrode array may be connected to the stimulation generator via a wire, thereby implementing suprathreshold electrical stimulation on the target muscle.

[0028] The electrode array may be a dual-channel stimulation electrode array connected to the target muscles, wherein the target muscles are the tibialis anterior and the gastrocnemius.

[0029] The rehabilitation system may further include an electromyographic signal amplifier, which may be configured to feed back the electromyographic signal collected by the electrode array to the microcontroller module for calculating muscle dynamic coordination.

[0030] The suprathreshold electrical stimulation mode of the neuromuscular electrical stimulation module can be as follows:

[0031]

[0032]

[0033] ES1 and ES2 are suprathreshold electrical stimulation applied to the tibialis anterior and gastrocnemius muscles, respectively; E is a gait event identified in real time; 1 indicates the application of suprathreshold electrical stimulation; and 0 indicates the cessation of suprathreshold electrical stimulation.

[0034] The suprathreshold electrical stimulation may be a symmetrical square wave electrical stimulation with an amplitude of 70V, a frequency of 40Hz, and a bandwidth of 50us.

[0035] The pneumatic musculoskeletal complex module may further include an electric air pump, an electric air valve, and an air pressure sensor.

[0036] The pneumatic musculoskeletal complex module may be further configured to determine inflation or deflation of the pneumatic muscle based on a comparison of an air pressure value in the pneumatic muscle measured by the air pressure sensor with a preset pressure threshold.

[0037] The musculoskeletal complex may also include an exoskeleton that serves as a container for all electronics, control circuit boards, and batteries.

[0038] The exoskeleton can be 3D printed from polylactide material.

[0039] The exoskeleton can be connected to the pneumatic muscles via exoskeleton extensions.

[0040] The vibration biofeedback module may include a vibration motor located between a first toe and a second toe on the sole of the foot.

[0041] The vibration motor can be controlled as follows:

[0042]

[0043] Among them, Z represents the control of the vibration motor, Z=1 means turning on the vibration motor, Z=0 means stopping the vibration motor, FSR 1max and FSR 5max are the maximum values ​​of the first pressure sensor at the first metatarsal head and the second pressure sensor at the fifth metatarsal head during the timing period after the heel leaves the ground, b% is the preset balance threshold, and E is the gait event recognized in real time.

[0044] The rehabilitation system may further include a fastening integration module for securing the rehabilitation system to the foot.

[0045] The fastening integration module may include a connecting piece for connecting and fixing the exoskeleton and a position fixing piece for fixing and cushioning the position of the pneumatic muscle.

[0046] The fastening integration module can be made of breathable and elastic textile materials.

[0047] The pneumatic muscle is made of polyvinyl chloride film.

[0048] In another embodiment of the present invention, a method for using the aforementioned time-phased, multimodal foot rehabilitation system driven by gait events is provided.

[0049] The scope of the present invention is defined by the claims, which are incorporated into this section by reference. For those skilled in the art, a more complete understanding of the embodiments of the present invention and additional advantages will be realized by considering the following detailed description of one or more embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The preferred features, embodiments, and variations of the present invention will be apparent from the following detailed description, which provides sufficient information for those skilled in the art to carry out the invention. The detailed description should not be construed as limiting the scope of the foregoing invention in any way. The detailed description will refer to the following figures:

[0051] Figure 1 A picture showing a conventional ankle-foot orthosis in the prior art is shown.

[0052] Figure 2 Shown is a structural block diagram of the control components of the rehabilitation system of the present invention.

[0053] Figure 3 A schematic diagram showing the mechanical assembly structure of a pneumatic musculoskeletal complex module and a neuromuscular electrical stimulation module according to an embodiment of the present invention is shown.

[0054] Figure 4 A schematic structural diagram of a pneumatic musculoskeletal complex module wrapped in a fastening integration module according to an embodiment of the present invention is shown.

[0055] Figure 5 A schematic structural diagram showing the distribution of pressure sensor modules and vibration biofeedback modules at the sole of the foot according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0056] The following describes a specific embodiment of the present invention in detail. The embodiment described herein is an illustration of unilateral use of the lower limb and is not intended to limit the present invention. The system and method proposed by the present invention can also be used for bilateral use of the lower limb.

[0057] The present invention provides a gait event-driven, time-phased, multimodal foot control and feedback rehabilitation system and its use method, which simultaneously uses multi-channel neuromuscular electrical stimulation, pneumatic musculoskeletal complex and sensory biofeedback for lower limb gait training, and can simultaneously correct foot drop and foot inversion problems.

[0058] Figure 2 FIG. 1 shows a structural block diagram of the rehabilitation system of the present invention. Figure 2 As shown, the rehabilitation system of the present invention includes, but is not limited to: 1) a pressure sensor module 110; 2) a neuromuscular electrical stimulation module 100; 3) a pneumatic musculoskeletal complex module 200; 4) a vibration biofeedback module 109; 5) a microcontroller module 111; 6) a fastening and integration module 102; and 7) an electromyographic signal amplifier 112. The neuromuscular electrical stimulation module 100 includes a stimulation generator 104 and an electrode array 103. The pneumatic musculoskeletal complex module 200 includes an electric air pump 106, an electric air valve 107, a musculoskeletal complex 105, and an air pressure sensor 108. The vibration biofeedback module 109 includes a vibration motor 402.

[0059] The pressure sensor module 110 is used to measure the pressure value of the foot during different gait events in dynamic gait in real time. The microcontroller module 111 receives the pressure value measured by the pressure sensor module 110, and identifies the different gait events in dynamic gait and the pressure balance on the inside and outside of the sole, so as to drive the corresponding functional modules to provide neuromuscular electrical stimulation, mechanical assistance and vibration biofeedback respectively, wherein the functional modules include the neuromuscular electrical stimulation module 100, the pneumatic musculoskeletal complex module 200, and the vibration biofeedback module 109. For example, the pressure sensor module 110 may include multiple pressure sensors. In one embodiment of the present invention, three pressure sensors may be provided, wherein the first pressure sensor is placed at the first metatarsal head of the foot, the second pressure sensor is placed at the fifth metatarsal head of the foot, and the third pressure sensor is placed at the heel. For example, each pressure sensor may be placed at the corresponding sole of the foot by adhesion.

[0060] Figure 3-5 The present invention shows a schematic diagram of the system structure for the ankle joint, which can simultaneously correct the foot drop and foot inversion problems of the lower limbs and improve muscle compensation. Figure 3-5 , further explaining the invented rehabilitation system.

[0061] Specifically, Figure 3 A schematic diagram showing the mechanical assembly structure of a pneumatic musculoskeletal complex module and a neuromuscular electrical stimulation module according to an embodiment of the present invention is shown; Figure 4A schematic diagram showing a structure in which a pneumatic musculoskeletal complex is wrapped in a fastening integration module according to an embodiment of the present invention is shown; and Figure 5 A schematic diagram showing the distribution of pressure sensors and vibration biofeedback modules at the sole of the foot according to an embodiment of the present invention is shown.

[0062] In one embodiment of the present invention, the electrode array 103 is connected to (for example, can be attached to) the skin surface of the tibialis anterior and gastrocnemius muscles on the affected side of the user's foot through adhesive stimulation electrodes (transcutaneous stimulation), and is connected to the stimulation generator 104 through a wire, and then the target muscles of the foot are electrically stimulated through the micro-control module 111 to help the user correct foot drop and inversion problems caused by muscle imbalance. In this embodiment, electrical stimulation can be applied to the target muscles, and can also be used to collect corresponding muscle electrical signals, and the collected muscle electrical signals are fed back to the micro-control module 111 through the electromyographic signal amplifier 112 for calculating muscle dynamic coordination. Figure 3 As shown, the electrode array 103 may include, for example, 2 electrodes.

[0063] The battery 202 provides power to the entire rehabilitation system and can be a rechargeable battery or a disposable battery. The wireless transmission chip 201 is configured to implement wireless information exchange between the microcontroller module 111 and the smart device.

[0064] like Figure 4 As shown, the pneumatic musculoskeletal complex includes an artificial muscle 305 and an exoskeleton 301 fixed on both sides of the ankle joint, wherein the exoskeleton 301 can be used as a container (i.e., a control box) that can house all electronic devices, a control circuit board, and a battery. The artificial muscle can be an electric field-driven artificial muscle, a gas-driven artificial muscle (pneumatic muscle), a heat-driven artificial muscle, a solvent absorption-driven artificial muscle, an electrochemically driven artificial muscle, or the like. In an embodiment of the present invention, for example, a pneumatic muscle 305 is selected as the artificial muscle of the present invention. The pneumatic muscle 305 can be an air bag that can be inflated by pressurized air, and it can be made of a thin film material, such as a polyvinyl chloride film or other material with small inflation deformation. The pneumatic muscle 305 is controlled by a microcontroller module 111 and is connected to an electric air pump 106, an electric air valve 107, and an air pressure sensor 108 via a gas conduit, thereby achieving inflation of the pneumatic muscle, maintaining air pressure, and deflation.

[0065] Exoskeleton 301 has an arcuate shape and can be 3D-printed from polylactide, for example. Exoskeleton 301 can be connected to pneumatic muscles 305 via exoskeleton extensions 303. When microcontroller 111 triggers the inflation of pneumatic muscles 305 and the pneumatic muscles 305 maintain a full state of air pressure, they work together with exoskeleton 301 as a musculoskeletal complex to provide mechanical support for the ankle joint, stabilizing the ankle joint's mechanical structure and preventing inversion. After deflation, pneumatic muscles 305 soften, allowing the ankle joint to achieve plantar flexion with a high degree of freedom and without external force, thereby strengthening the ankle muscles and preventing muscle atrophy.

[0066] The fastening integration module 102 used to secure the rehabilitation system to the user's foot can be made of, for example, a breathable elastic textile material, thereby integrating the pneumatic musculoskeletal complex and the wires therein. The fastening integration module 102 can include connectors 304 for connecting and securing the control box consisting of the exoskeleton 301 on both sides of the ankle joint, thereby facilitating the wearing of the system and enhancing wearing comfort. In one embodiment of the present invention, the connectors 304 can be, for example, elastic Velcro with a certain degree of elasticity. The fastening integration module 102 can also include position fixing members 302 for fixing and cushioning the position of the pneumatic muscles 305 during inflation and deflation. In one embodiment of the invention, the position fixing members 302 can be made of, for example, a breathable textile material with a certain degree of elasticity to facilitate position fixing and cushioning. In addition, the position fixing members 302 can wrap around the wires between the pressure sensor module 110 and the vibration biofeedback module 109 on the sole of the foot and the control box.

[0067] Reference Figure 5 , three (for example, thin film-shaped) pressure sensors 401 are connected to the micro-control module 111 through circuit wires, wherein the first pressure sensor is placed at the first metatarsal head, the second pressure sensor is placed at the fifth metatarsal head, and the third pressure sensor is placed at the heel. The signals from the pressure sensors are used to identify gait events and calculate the balance of the plantar foot in real time to control the coordination of the various functional modules of the system in different phases. The vibration motor 402 is placed between the first toe and the second toe and is connected to the micro-control module 111 through a circuit wire. During the gait process, the vibration motor 402 provides necessary vibration biofeedback to prompt the user to actively adjust the plantar force balance to correct the problem of inversion of the foot.

[0068] In the present invention, when the foot is in a dynamic gait process, the system identifies gait events in the following way to achieve real-time control:

[0069]

[0070] Where E represents the gait event recognized in real time.脚跟 (t) are the real-time pressure data of the first pressure sensor at the first metatarsal head, the real-time pressure data of the second pressure sensor at the fifth metatarsal head, and the real-time pressure data of the third pressure sensor at the heel. 脚跟 They are the threshold strengths of the first pressure sensor, the second pressure sensor, and the third pressure sensor respectively. The threshold strengths can be set as needed, for example, preset to a certain percentage of the maximum value of each pressure sensor during dynamic gait, such as 40%.

[0071] In the initialization state, the heel of the affected side steps on the ground, and the pneumatic muscle 305 in the pneumatic musculoskeletal complex module 200 is in an inflated state to provide mechanical support therefor.

[0072] I) When the pressure value of the third pressure sensor at the heel is less than or equal to the set threshold, the system recognizes it as a "heel-off" event (the start of the stride phase). The pneumatic muscle 305 in the pneumatic musculoskeletal complex module 200 is triggered to enter a deflated state through the microcontroller module 111, mechanical support is stopped, and suprathreshold electrical stimulation is applied to the target muscle (such as the gastrocnemius muscle) through the neuromuscular electrical stimulation module 100 to achieve ankle plantar flexion. II) After timing a fixed time value, such as 2 seconds, the system stops releasing electrical stimulation to the target muscle (such as the gastrocnemius muscle) through the microcontroller module 111; at the same time, the system uses the plantar pressure of the ankle plantar flexion to determine whether to instruct the vibration biofeedback module 109 to provide vibration biofeedback to correct the plantar force balance. III) Wait until the first, second, and third pressure sensors are all less than or equal to their respective preset thresholds, and the system identifies it as a "foot off the ground" event (in the middle of the stride phase), and triggers the pneumatic muscle 305 in the pneumatic musculoskeletal complex module 200 through the microcontroller module 111 to start inflating, while simultaneously releasing suprathreshold electrical stimulation to the target muscle (such as the tibialis anterior muscle) to achieve ankle dorsiflexion (correct foot drop). At this time, the vibration biofeedback module 109 will also provide necessary vibration biofeedback to remind the user 101 to improve foot balance in the subsequent stance phase. IV) When the pressure value of the third pressure sensor at the heel is greater than the set threshold, the system identifies it as a "heel touchdown" event (start of the stance phase), controls the microcontroller module 111 to cause the neuromuscular electrical stimulation module 100 to stop releasing electrical stimulation to the target muscle (such as the tibialis anterior muscle), and the vibration biofeedback module 109 stops vibration biofeedback. At this time, the air pressure value in the pneumatic muscle 305 reaches the maximum. V) When the pressure value of the third pressure sensor at the heel is less than the threshold, the system recognizes that the heel leaves the ground (start of the stride phase), and the gait enters a cyclic process.

[0073] The neuromuscular electrical stimulation module 100 includes an electrode array 103 and a stimulation generator 104. In this embodiment, the electrode array 103 is a dual-channel stimulation electrode array. The dual-channel stimulation electrode array is attached to the antagonistic muscle pair (such as the tibialis anterior and gastrocnemius) of the controlled joint movement (such as ankle dorsiflexion and plantar flexion) to perform alternating, time-phased transcutaneous electrical stimulation to induce effective contraction of the target muscle in the relevant phase, which is used to guide the muscle coordination involved in ankle dorsiflexion and plantar flexion during gait. The controlled mode of neuromuscular electrical stimulation is as follows:

[0074]

[0075]

[0076] Where ES1 and ES2 represent suprathreshold neuromuscular electrical stimulation of the target muscles (i.e., the tibialis anterior and gastrocnemius muscles), respectively. The stimulation intensity is preset to a fixed value based on the user's needs, such as a symmetrical square wave electrical stimulation with an amplitude of 70V, a frequency of 40Hz, and a bandwidth of 50us. During dynamic gait, when the sole of the foot leaves the ground, the system provides corresponding electrical stimulation (ES1=1) to cause the tibialis anterior muscle to contract, driving the ankle joint to complete dorsiflexion. When the heel touches the ground, the system stops this electrical stimulation (ES1=0). When the heel leaves the ground, the system provides corresponding electrical stimulation (ES2=1) to cause the gastrocnemius muscle to contract, driving the ankle joint to complete plantar flexion. This neuromuscular electrical stimulation lasts for a preset fixed time of n seconds, such as 2 seconds. After 2 seconds, the system stops this electrical stimulation (ES2=0). The stimulating electrode array can also obtain muscle electrical signals from the skin surface through the stimulating electrodes, which are amplified by the electromyographic signal amplifier and fed back to the microcontroller module 111.

[0077] The pneumatic musculoskeletal complex module 200 includes, but is not limited to, a musculoskeletal complex 105 that combines pneumatic muscles 305 with an exoskeleton 301, an electric air valve 107, an electric air pump 106, and an air pressure sensor 108. The control method thereof is as follows:

[0078]

[0079] Where P and V represent the control of the electric air pump 106 and the electric air valve 107, respectively. Ap and Tp represent the air pressure value and the preset pressure threshold in the pneumatic muscle 305, respectively. The preset pressure threshold is set according to the user's individual needs. When the foot is identified as off-the-ground and the air pressure in the pneumatic muscle 305 is less than or equal to the preset threshold, the system activates the electric air pump 106 and closes the electric air valve 107, triggering the inflation of the pneumatic muscle 305 to provide mechanical support to the target joint position. When the air pressure in the pneumatic muscle 305 exceeds the preset threshold, the system stops the electric air pump 106 and closes the electric air valve 107, maintaining the air pressure in the pneumatic muscle 305 near the preset threshold to prevent damage to the pneumatic muscle 305 due to overinflation. When the heel is identified as off-the-ground, the system stops the electric air pump 106 and opens the electric air valve 107, triggering the deflation of the pneumatic muscle 305 to enable free movement of the ankle joint during push-off. The exoskeleton 301 and its extension 303 in the musculoskeletal complex 105 are designed to fit the user's calves in an arc shape, and together with the pneumatic muscles, provide mechanical support for the joints to help them fix their angles and prevent soft tissue damage caused by inversion of the foot.

[0080] In one embodiment of the present invention, the vibration biofeedback module 109 may be a vibration motor 402 located between the first and second toes of the foot, which operates based on real-time pressure data FSR1 from a first pressure sensor at the first metatarsal head and real-time pressure data FSR5 from a second pressure sensor at the fifth metatarsal head, and is controlled as follows:

[0081]

[0082] Where Z represents the control of the vibration motor 402, FSR 1max and FSR 5max are the maximum values ​​of the first pressure sensor at the first metatarsal head and the second pressure sensor at the fifth metatarsal head during the timing period after the heel leaves the ground, and b% is the preset balance threshold, such as 50%. 5max After multiplying by the preset balance threshold, it is still greater than or equal to FSR 1max , the system identifies the gait imbalance and turns on the vibration motor 402 (Z=1) to provide vibration biofeedback to remind the user 101 to adjust the force balance of the affected side of the foot. The vibration intensity is the mechanical vibration threshold that the user can perceive. 5max After multiplying by the preset balance threshold, it is less than FSR 1max , the system does not trigger the vibration motor 402 (Z=0), that is, the plantar balance meets the standard. When it is identified as a heel strike event, the system turns off the vibration motor 402 and stops the vibration biofeedback.

[0083] The microcontroller module 111 receives real-time signals from the sequential pressure sensor module 110 and the air pressure sensor 108 to identify gait events and issues commands to control the operation of the neuromuscular electrical stimulation module 100, the pneumatic musculoskeletal complex module 200, and the vibration biofeedback module 109 in real time. Simultaneously, the microcontroller module 111 receives muscle electrical signals measured by the stimulating electrode array 103, normalizes and calculates them, and generates real-time automated assessment parameters. These are then transmitted to a smart device via wireless data exchange. Training records and assessment parameters are then uploaded to a cloud server for archiving, management, and analysis by medical personnel. Automated assessment parameters include, but are not limited to, muscle activation levels and antagonist muscle pair co-contraction indexes; smart devices include, but are not limited to, smartphones, smart tablets, and portable computers.

[0084] The system and method of the present invention have the following advantages:

[0085] 1) A multimodal (integration of multiple assistive technologies) and time-phased real-time control method is used to simultaneously correct foot drop and foot inversion, and improve muscle compensation and atrophy to reshape normal gait.

[0086] 2) Design of wearable foot and ankle multimodal system structure.

[0087] 3) Provide biofeedback signals to allow users to correct their foot balance independently.

[0088] 4) Improve muscle coordination and prevent muscle atrophy through neuromuscular electrical stimulation.

[0089] In addition to being used to simultaneously correct foot drop and foot inversion problems for users with unilateral hemiplegia as in the embodiment, this lower limb exercise rehabilitation system can also be used by users with bilateral paralysis, such as those with spinal cord injuries, after online pairing to provide them with bilateral lower limb exercise rehabilitation training.

[0090] Although the present disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the disclosure as described herein. Accordingly, the scope of the present disclosure should be limited only by the appended claims.

Claims

1. A gait event-driven, time-phased, multimodal foot rehabilitation system, comprising: A pressure sensor module (110), which is connected to the sole of the user's foot and measures the pressure distribution values ​​of different areas of the sole of the foot in real time; a microcontrol module (111) receiving a measured pressure value, comparing the measured pressure value with a preset threshold value to identify different gait events in a dynamic gait and the pressure balance between the inner and outer sides of the sole, and controlling the neuromuscular electrical stimulation module (100), the pneumatic musculoskeletal complex module (200), and / or the vibration biofeedback module (109) in real time to perform corresponding operations; a neuromuscular electrical stimulation module (100), the neuromuscular electrical stimulation module being configured to initiate or stop suprathreshold electrical stimulation of target muscles of the foot based on gait events identified by the microcontroller module (111); a pneumatic musculoskeletal complex module (200), comprising a musculoskeletal complex (105) for providing mechanical support to a foot, and configured to deflate or inflate pneumatic muscles (305) of the musculoskeletal complex (105) based on gait events identified by the microcontroller module (111) to secure the ankle during a stance phase or to relax the ankle during a stride phase of a gait cycle; and a vibration biofeedback module (109), configured to provide biofeedback to correct the force balance of the user's sole when the microcontroller module (111) identifies an imbalance in the pressure between the inner and outer sides of the sole, The gait events include heel strike, heel lift-off and sole lift-off. Wherein, the microcontroller module (111) is configured as follows: When the heel is detected to be off the ground, the pneumatic muscle (305) is triggered to deflate, and a suprathreshold electrical stimulation is performed on the first target muscle through the neuromuscular electrical stimulation module (100); After a fixed time value and before the sole of the foot leaves the ground, the electrical stimulation of the first target muscle is stopped, and when an imbalance in pressure between the inner and outer sides of the sole of the foot is identified, the vibration biofeedback module (109) is instructed to provide vibration; When the sole of the foot is detected to be off the ground, the pneumatic muscle (305) is triggered to inflate, and a second target muscle is subjected to suprathreshold electrical stimulation via the neuromuscular electrical stimulation module (100), and when an imbalance in pressure between the inner and outer sides of the sole of the foot is identified, the vibration biofeedback module (109) is instructed to provide vibration; When the heel strikes the ground, the electrical stimulation of the second target muscle is stopped, the vibration is stopped, and the pneumatic muscle (305) is inflated to a maximum value.

2. The foot rehabilitation system according to claim 1, wherein: The pressure sensor module (110) comprises a first pressure sensor placed at the first metatarsal head of the sole of the foot, a second pressure sensor placed at the fifth metatarsal head of the sole of the foot, and a third pressure sensor placed at the heel.

3. The foot rehabilitation system according to claim 2, wherein: The microcontroller module (111) recognizes the gait event in the following manner to achieve real-time control: Among them, E is the real-time recognition of gait events, FSR1(t), FSR5(t), FSR 脚跟 (t) are the real-time pressure data measured by the first pressure sensor, the second pressure sensor, and the third pressure sensor, T1, T5, T 脚跟 They are respectively the preset thresholds of the first pressure sensor, the second pressure sensor, and the third pressure sensor.

4. The foot rehabilitation system according to claim 3, wherein: When the pressure value measured by the third pressure sensor is less than the preset threshold, the micro-control module (111) identifies the gait event as the heel-off.

5. The foot rehabilitation system according to claim 3, wherein: When the first pressure sensor, the second pressure sensor and the third pressure sensor are all less than or equal to their respective preset thresholds, the micro-control module (111) identifies the gait event as the foot leaving the ground.

6. The foot rehabilitation system according to claim 3, wherein: When the pressure value measured by the third pressure sensor is greater than the preset threshold, the micro-control module (111) recognizes the gait event as the heel strike.

7. The foot rehabilitation system according to claim 1, wherein: The neuromuscular electrical stimulation module (100) comprises a stimulation generator (104) and an electrode array (103), wherein the electrode array (103) is connected to the stimulation generator (104) via a wire, thereby implementing suprathreshold electrical stimulation on the target muscle.

8. The foot rehabilitation system according to claim 7, wherein: The electrode array (103) is a dual-channel stimulation electrode array connected to the target muscles, wherein the first target muscle is the gastrocnemius muscle and the second target muscle is the tibialis anterior muscle.

9. The foot rehabilitation system according to claim 7, wherein: The foot rehabilitation system further includes an electromyographic signal amplifier (112), which is configured to feed back the electromyographic signal collected by the electrode array (103) to the microcontroller module (111) for calculating muscle dynamic coordination.

10. The foot rehabilitation system according to claim 8, wherein: The above-threshold electrical stimulation mode of the neuromuscular electrical stimulation module (100) is as follows: ES1 and ES2 are suprathreshold electrical stimulation applied to the tibialis anterior and gastrocnemius muscles, respectively; E is a gait event identified in real time; 1 indicates the application of suprathreshold electrical stimulation; and 0 indicates the cessation of suprathreshold electrical stimulation.

11. The foot rehabilitation system according to claim 1, wherein: The above-threshold electrical stimulation is a symmetrical square wave electrical stimulation with an amplitude of 70V, a frequency of 40Hz, and a bandwidth of 50us.

12. The foot rehabilitation system according to claim 1, wherein: The pneumatic musculoskeletal complex module (200) further comprises an electric air pump (106), an electric air valve (107) and an air pressure sensor (108).

13. The foot rehabilitation system according to claim 12, wherein: The pneumatic musculoskeletal complex module (200) is further configured to determine the inflation or deflation of the pneumatic muscle (305) based on a comparison between the air pressure value in the pneumatic muscle (305) measured by the air pressure sensor (108) and a preset pressure threshold.

14. The foot rehabilitation system according to claim 1, wherein the musculoskeletal complex (105) further comprises an exoskeleton (301), and the exoskeleton (301) can serve as a container for all electronic devices, control circuit boards and batteries.

15. The foot rehabilitation system according to claim 14, wherein the exoskeleton (301) is 3D printed from polylactide material.

16. The foot rehabilitation system according to claim 14, wherein the exoskeleton (301) is connected to the pneumatic muscle (305) via an exoskeleton extension (303).

17. The foot rehabilitation system according to claim 1, wherein: The vibration biofeedback module (109) includes a vibration motor (402) located between a first toe and a second toe on the sole of the foot.

18. The foot rehabilitation system according to claim 17, wherein: The vibration motor (402) is controlled as follows: Wherein, Z represents the control of the vibration motor (402), Z=1 represents turning on the vibration motor (402), and Z=0 represents stopping the vibration motor (402), FSR 1max and FSR 5max are the maximum values ​​of the first pressure sensor at the first metatarsal head and the second pressure sensor at the fifth metatarsal head during the timing period after the heel leaves the ground, b% is the preset balance threshold, and E is the gait event recognized in real time.

19. The foot rehabilitation system according to claim 14, wherein: The foot rehabilitation system further comprises a fastening integration module (102) for fixing the foot rehabilitation system to the foot.

20. The foot rehabilitation system according to claim 19, wherein: The fastening integration module (102) comprises a connecting piece (304) for connecting and fixing the exoskeleton (301) and a position fixing piece (302) for fixing and buffering the position of the pneumatic muscle (305).

21. The foot rehabilitation system according to claim 19, wherein: The fastening integration module (102) is made of breathable and elastic textile material.

22. The foot rehabilitation system according to claim 1, wherein: The pneumatic muscle (305) is a polyvinyl chloride film.

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