Ankle-foot orthosis based on passive double clutch and correction method thereof

Abstract

The present invention discloses an ankle-foot orthosis based on a passive dual-clutch and an orthosis method thereof. The ankle-foot orthosis includes a leg support mechanism, a rotating pair, an assist spring, a first clutch device, and a second clutch device; the first clutch device includes a storage box, a displacement transmission mechanism, a trigger block, a first clutch mechanism, and a cover plate; the second clutch device includes a fixed shell, an outer end cover, a first fixed spindle, an energy storage and release mechanism, and the energy storage and release mechanism includes a second clutch mechanism and an energy storage mechanism. The ankle-foot orthosis of the present invention stores energy in the assist spring in the early and middle stages of support through the first clutch device, and assists the patient in the late stages of support, thereby improving the walking ability of hemiplegic patients; at the same time, in the late stages of support, the coil spring is stored with energy through the second clutch device, and the patient's foot is prevented from sagging during the swinging stage, thereby solving the problem of hemiplegic patients falling due to their feet sagging and hitting the ground.

Description

Technical Field

[0001] The present invention relates to the technical field of assistive exoskeleton robots, and in particular to an exoskeleton that can be worn on the human body and has the functions of assisting and preventing foot drop, in particular to an ankle-foot orthosis based on a passive double clutch and a correction method thereof. Background Art

[0002] According to statistics from the seventh national census in 2021, China's population aged 60 and over reached 264 million, accounting for 18.70% of the total population. Of these, nearly 191 million were aged 65 and over, accounting for 13.50%. Compared to the sixth national census in 2010, these proportions increased by 5.44 percentage points and 4.63 percentage points, respectively. With the increasing aging of the population, the problem of hemiplegia caused by stroke has become more serious among the elderly. Hemiplegic patients are prone to foot drop, inversion, and other movement disorders, which seriously affect their daily activities and quality of life. Addressing walking difficulties in hemiplegic patients is crucial. Generally, patients can perform normal plantar flexion movements. Depending on their specific health conditions, selective treatments such as orthodontic treatment, functional electrical stimulation, physical therapy, and surgery can provide some walking assistance. While these methods provide some biomechanical support, they are merely supplemental treatments outside of walking and cannot provide assistance or gait correction during walking, nor can they eliminate significant gait complications. This makes the application of exoskeletons increasingly important.

[0003] In recent years, exoskeleton robotics technology has gradually emerged, developed, and entered into practical application. Exoskeleton robotics are generally categorized into three types based on their intended use: human augmentation exoskeletons, which aim to enhance human load-bearing capacity and are typically used in military settings; rehabilitation exoskeletons, primarily used in rehabilitation therapy; and assistive exoskeletons, which aid the disabled or elderly in mobility. Given the increasing number of patients with lower limb hemiplegia who urgently need to improve their ability to walk normally, research on lower limb exoskeletons, particularly assistive, portable, wearable ankle-foot orthoses, has become increasingly urgent.

[0004] Ankle-foot orthoses (AFOs) can be categorized as active and passive. Active AFOs are generally complex, with numerous and heavy components, but they offer a wider range of functions. Passive AFOs, on the other hand, lack dynamic components within the exoskeleton mechanism and rely on ingenious structural design to achieve their intended functions. Although passive AFOs offer fewer functions than actively controlled AFOs, their simplicity and low cost make them particularly effective in reducing gait impairment in patients with hemiplegia who still retain plantar flexion. Current research, both domestically and internationally, has largely favored active AFOs, with limited research on passive AFOs. Traditional passive AFOs typically consist of a monolithic mechanical brace that supports the foot and prevents toe drop during swing phase. While these braces can correct gait impairments to a certain extent, they cannot address gait impairments caused by foot drop during the initial phase of support. Furthermore, these devices completely restrict ankle joint motion, potentially leading to atrophy of the ankle flexor muscles with long-term wear.

[0005] Therefore, it is necessary to develop a flexible passive ankle-foot orthosis that can not only provide assistance in the late support phase to further improve the patient's motor ability, but also enable the patient to avoid the abnormal gait of foot drop during the swing phase. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings of the existing technology and proposes an ankle-foot orthosis based on a passive dual-clutch and a correction method thereof. The orthosis can not only collect the negative work of the ankle joint to provide assistance to hemiplegic patients, but also correct the foot drop problem of hemiplegic patients during the swing phase.

[0007] In order to achieve the above effects, the technical solution adopted by the present invention is:

[0008] A passive dual-clutch ankle-foot orthosis comprises a leg support mechanism fixed to both sides of the calf by straps, a revolving pair rotatably connected to the bottom of the leg support mechanism, a booster spring arranged parallel to the calf, a first clutch device fixedly connected to the outside of the bottom of the revolving pair, and a second clutch device fixedly connected to the outside of the leg support mechanism.

[0009] The first clutch device includes a storage box fixedly arranged on the side of the sole of the foot, a displacement transmission mechanism arranged inside the storage box, a trigger block fixedly connected to the power input end of the displacement transmission mechanism, a first clutch mechanism rotatably connected to the power output end of the displacement transmission mechanism, and a cover plate fixedly connected to the storage box, wherein the trigger block is hinged to the rear end of the bottom surface of the storage box and can move in and out of the storage box;

[0010] The first clutch mechanism includes a locking block that moves horizontally back and forth, a trigger that is vertically movably inserted into the front end of the bottom of the storage box, and a lock column fixed to the inner end of the trigger. One end of the trigger protrudes below the bottom surface of the storage box, and the other end is movably inserted into the bottom wall of the storage box and drives the lock column to lock and unlock the locking block.

[0011] The upper end of the assist spring is fixedly connected to one side of the top of the leg support mechanism, and the lower end is fixedly connected to the locking block via a first flexible cable;

[0012] The second clutch device includes a fixed shell fixedly connected to the leg support mechanism, an outer end cover fixedly connected to the outer end surface of the fixed shell, a first fixed spindle fixedly installed between the fixed shell and the outer end cover, and an energy storage and release mechanism installed on the first fixed spindle. The energy storage and release mechanism includes a second clutch mechanism and an energy storage mechanism embedded in the second clutch mechanism. The clutch control end of the second clutch mechanism is fixedly connected to the locking block through a third flexible rope, and the power execution end of the second clutch mechanism is fixedly connected to the bandage fixed to the toe through a second flexible rope.

[0013] Furthermore, the leg support mechanism includes a first calf side panel attached to the outer side of the calf and placed vertically, a second calf side panel attached to the inner side of the calf and parallel to the first calf side panel, and an adjustment connecting plate slidably connected to the bottom of the first calf side panel. The top and bottom of the first calf side panel and the second calf side panel are respectively fixedly connected to a calf upper bracket and a calf lower bracket both located on the back side of the calf, and the side of the calf upper bracket is fixedly connected to a lifting bolt.

[0014] Furthermore, the rotating pair includes a triangular swing rod and a second fixed shaft connected to the top of the triangular swing rod, the second fixed shaft is sleeved on the bottom of the adjustment connecting plate, and a strip-shaped through hole is opened on the bottom section of the triangular swing rod.

[0015] Furthermore, the displacement transmission mechanism includes two groups of symmetrically arranged and synchronously moving connecting rod mechanisms, each connecting rod mechanism includes a C-shaped rod fixedly connected to the trigger block, a first connecting rod rotatably connected to the top end of the C-shaped rod, and a parallel four-bar mechanism rotatably connected to the other end of the first connecting rod. The parallel four-bar mechanism is rotatably connected to a fifth connecting rod at one end away from the first connecting rod, and the other end of the fifth connecting rod is rotatably connected to the locking block.

[0016] Furthermore, the first clutch mechanism also includes a first rolling wheel and a second rolling wheel respectively threadedly connected to both sides of the locking block, and a support platform is fixedly provided at the internal front end of the storage box, and the first rolling wheel and the second rolling wheel roll horizontally on the top surface of the support platform. A through lock column hole is provided on the top surface of the support platform, and the top end of the lock column can be movably extended and retracted in the lock column hole, and the bottom end of the lock column is threadedly connected to a force block, and the force block is located above the bottom wall of the storage box, and the bottom end of the force block is threadedly connected to the trigger, and the lock column is also covered with a first compression spring located between the support platform and the force block.

[0017] Furthermore, the second clutch mechanism includes a one-way transmission wheel rotatably sleeved on the first fixed spindle, a locking pin in a clutch relationship with the one-way transmission wheel, and a cylindrical pin seat fixedly sleeved on the first fixed spindle and located between the one-way transmission wheel and the outer end cover. The end surface of the one-way transmission wheel close to the locking pin is provided with one-way transmission grooves evenly distributed around the circumference. One end of the locking pin is movably inserted in the cylindrical pin seat and detachably embedded in the one-way transmission groove. The other end of the locking pin is fixedly connected to the third flexible cable. A wire groove is provided on the wheel cylindrical surface of the one-way transmission wheel, and one end of the second flexible cable is wound in the wire groove.

[0018] Furthermore, a second compression spring is sleeved on the locking pin, and the cylindrical pin seat is fixedly connected to a support seat near the outer end cover side, and the cylindrical pin seat is axially positioned by a shaft retaining ring.

[0019] Furthermore, the energy storage mechanism includes a coil spring fixing bracket sleeved on the first fixed spindle and embedded in the one-way transmission wheel, a coil spring connected between the first fixed spindle and the coil spring fixing bracket, and a bearing seat located outside the coil spring fixing bracket is fixedly connected to the end face of the one-way transmission wheel.

[0020] Furthermore, the ankle-foot orthosis based on the passive dual clutch also includes a pulley guide mechanism, which includes a first pulley guide mechanism fixedly arranged on the rear end surface of the storage box, a second pulley guide mechanism fixedly arranged on the lower leg bracket, and a third pulley guide mechanism fixedly arranged on the outer end cover. The first flexible cable passes around the second pulley guide mechanism and the first pulley guide mechanism in sequence, and the third flexible cable passes around the third pulley guide mechanism.

[0021] A method for correcting an ankle-foot orthosis based on a passive double clutch is also provided, comprising the following steps:

[0022] S10. The ankle-foot orthosis patient wears and fixes the passive double-clutch ankle-foot orthosis on the calf and foot, and walks with support.

[0023] S20, in the initial support stage of foot contact, the trigger block touches the ground and swings upward, causing the locking block to translate forward via the displacement transmission mechanism, and the first flexible cable connected to the locking block stretches the assist spring to generate elastic potential energy;

[0024] When the locking block moves forward, it also pulls the third flexible cable to separate the locking pin from the one-way transmission wheel, the second compression spring is compressed, and the one-way transmission wheel is in a free rotation state;

[0025] S30, in the middle stance phase, the trigger at the front foot touches the ground and moves upward, the locking post moves upward and inserts into the locking block, locking the first clutch mechanism, storing energy in the assist spring, and compressing the first compression spring;

[0026] The calf swings forward relative to the ankle joint, which stretches the assist spring a second time and increases the energy storage capacity of the assist spring.

[0027] S40. In the later stage of support, as the heel is lifted, the distance between the top of the assist spring and the bottom of the first flexible cable becomes shorter, and the energy in the assist spring is released to assist the patient's foot.

[0028] When the ankle joint performs plantar flexion, the second flexible cable pulls the one-way transmission wheel to rotate clockwise, causing the coil spring to curl and store energy. When the plantar flexion movement ends, the trigger is lifted off the ground, and the first clutch mechanism is unlocked under the restoring action of the first compression spring. The locking pin is locked with the one-way transmission wheel under the restoring action of the second compression spring, so that the one-way transmission wheel can only transmit in one direction.

[0029] S50. In the initial swing phase after the calf is lifted, the coil spring releases energy to rotate the one-way drive wheel counterclockwise. The second flexible cable is reeled in to lift the toes to prevent them from dropping. The one-way drive wheel cannot rotate clockwise due to the locking pin, so that the foot remains in the lifted toes position.

[0030] S60, repeating steps S20 to S50 to complete the ankle-foot orthosis process for the ankle-foot orthosis patient;

[0031] S70: After the correction is completed, the passive dual-clutch ankle-foot orthosis is removed from the lower leg and foot of the ankle-foot orthosis patient.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] The ankle-foot orthosis based on a passive dual-clutch proposed in the present invention can store energy in the assist spring in the early and middle stages of support through the first clutch device, and provide assistance to the patient in the late stage of support, thereby improving the walking ability of hemiplegic patients; at the same time, in the late stage of support, the coil spring is stored with energy through the second clutch device, and the patient's foot is prevented from dropping during the swinging stage, solving the problem of hemiplegic patients falling due to the drooping of their feet and hitting the ground; it has the advantages of being portable, wearable, light weight, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0035] Figure 2 It is a structural schematic diagram of the leg support mechanism of the present invention;

[0036] Figure 3 This is a schematic diagram of the installation of the rotary pair of the present invention;

[0037] Figure 4 This is a schematic diagram of the structure of the first clutch device of the present invention. Figure 1 ;

[0038] Figure 5 This is a schematic diagram of the structure of the first clutch device of the present invention. Figure 2 ;

[0039] Figure 6 It is a structural schematic diagram of the displacement transmission mechanism of the present invention;

[0040] Figure 7 is an exploded view of the first clutch mechanism of the present invention;

[0041] Figure 8 is an exploded view of the second clutch device of the present invention;

[0042] Figure 9 Installation diagram of the coil spring of the present invention Figure 1 ;

[0043] Figure 10 Installation diagram of the coil spring of the present invention Figure 2 ;

[0044] Figure 11 This is a schematic diagram of the structure of the one-way rotating wheel of the present invention. Figure 1 ;

[0045] Figure 12 This is a schematic diagram of the structure of the one-way rotating wheel of the present invention. Figure 2 ;

[0046] Figure 13 1 is a schematic cross-sectional view of the one-way rotating wheel of the present invention;

[0047] Figure 14 It is a structural schematic diagram of the fixed shell of the present invention.

[0048] Among them: 1 leg support mechanism, 11 first calf side plate, 12 second calf side plate, 13 adjustment connecting plate, 14 calf upper bracket, 15 calf lower bracket, 2 rotation pair, 21 triangular swing rod, 22 second fixed spindle, 23 third rolling bearing, 24 nut, 3 assist spring, 4 strap, 5 first clutch device, 51 storage box, 52 displacement transmission mechanism, 5211 C-type rod, 5212 first connecting rod, 5213 second connecting rod, 5214 third connecting rod, 5215 fourth connecting rod, 5216 fifth connecting rod, 53 trigger block, 54 first clutch mechanism, 541 locking block, 542 locking column, 543 force block, 544 trigger, 545 first compression spring, 546 first rolling wheel, 547 second rolling wheel, 6 second clutch device, 61 first fixed spindle, 62 fixed housing, 63 outer end cover, 6411 one-way transmission wheel, 6412 locking pin, 6413 second compression spring, 6414 cylindrical pin seat, 6415 support seat, 6416 shaft retaining ring, 6421 coil spring fixing bracket, 6422 coil spring, 6423 bearing seat, 6424 first rolling bearing, 6425 second rolling bearing, 71 first flexible cable, 72 second flexible cable, 73 third flexible cable, 81 first pulley guide mechanism, 82 second pulley guide mechanism, 83 third pulley guide mechanism. DETAILED DESCRIPTION

[0049] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0050] See also Figure 1 A passive dual-clutch ankle-foot orthosis comprises a leg support mechanism 1 fixed to both sides of the calf by a strap 4, a rotating pair 2 rotatably connected to the bottom of the leg support mechanism 1, a booster spring 3 arranged parallel to the calf, a first clutch device 5 fixedly connected to the outer side of the bottom of the rotating pair 2, and a second clutch device 6 fixedly connected to the outer side of the leg support mechanism 1.

[0051] Specifically, such as Figure 2As shown, the leg support mechanism 1 includes a first calf side panel 11 attached to the outside of the calf and positioned vertically, a second calf side panel 12 attached to the inside of the calf and parallel to the first calf side panel 11, and an adjustment connecting plate 13 slidably and adjustably connected to the bottom of the first calf side panel 11. The top and bottom of the first and second calf side panels 11, 12, are respectively fixedly connected to an upper calf support 14 and a lower calf support 15, both located on the back of the calf. The side of the upper calf support 14 is fixedly connected to an eyebolt 16. More specifically, the side of the first calf side panel 11 is provided with a plurality of strip-shaped through slots arranged in an array. The top of the side of the adjustment connecting plate 13 is provided with strip-shaped through slots corresponding to the strip-shaped through slots. The adjustable connection between the adjustment connecting plate 13 and the first calf side panel 11 is achieved by a pair of bolts located in the strip-shaped through slots. By adjusting the overall length of the fixed adjustment connecting plate 13 and the first calf side panel 11, the overall length can be adjusted to accommodate the needs of AFO patients with different calf lengths. In order to save processing costs and improve the substitutability between components, the second calf side panel 12 has the same structure as the first calf side panel 11. The upper calf support 14 and the lower calf support 15 are both "C"-shaped structures, and their respective ends are fixedly connected to the first calf side panel 11 and the second calf side panel 12 by a pair of bolts, so that the first calf side panel 11 and the second calf side panel 12 form an integral frame structure, and can be conveniently put on the calf area and conveniently removed from the calf area as a whole. The front top and bottom of the first calf side panel 11 and the second calf side panel 12 are respectively connected by a strap 4, so that the frame structure can be reliably fixed on the calf. A countersunk hole is set at the center position of the rear side surface of the upper calf support 14 and a nut is embedded therein. The eye bolt 16 is threadedly connected to the nut, thereby fixedly connected to the calf support 14.

[0052] like Figure 3 As shown, the revolving pair 2 includes a triangular swinging rod 21 and a second fixed spindle 22 connected to the top of the triangular swinging rod 21. The second fixed spindle 22 is sleeved on the bottom of the adjustment connecting plate 13, and a strip-shaped through-hole is provided on the bottom section of the triangular swinging rod 21. Specifically, the triangular swinging rod 21 is a right-angled triangle structure, and a bearing mounting hole is provided at the acute angle connection point at its top. The second fixed spindle 22 is a three-step shaft structure, and a third rolling bearing 23 is sleeved on its second step shaft, and its end shaft section is provided with an external thread. The third rolling bearing 23 is embedded in the bearing mounting hole. A bolt hole is provided at the bottom end of the adjustment connecting plate 13. The end shaft section of the second fixed spindle 22 passes through the bolt hole and is threadedly connected to the nut 24 to be fastened to the adjustment connecting plate 13, thereby rotating the triangular swinging rod 21 to be connected to the adjustment connecting plate 13.

[0053] like Figure 4 and Figure 5As shown, the first clutch device 5 includes a storage box 51 fixedly mounted on the side of the foot sole, a displacement transmission mechanism 52 disposed within the storage box 51, a trigger block 53 fixedly connected to the power input end of the displacement transmission mechanism 52, a first clutch mechanism 54 rotatably connected to the power output end of the displacement transmission mechanism 52, and a cover fixedly connected to the storage box 51. The trigger block 53 is hinged to the rear end of the bottom surface of the storage box 51 and can move in and out of the storage box 51. Specifically, the side wall of the storage box 51 is provided with a plurality of rows of threaded holes, and a row of bolt holes is provided below the threaded holes. The upper end of the side wall of the storage box 51 is connected to the threaded holes via screws located in the strip-shaped through-holes, thereby fixing the storage box to the triangular swing rod 21. The lower end is fixedly connected to the sole of the foot of the AFO patient via a pair of bolts, thereby ensuring that the movement of the storage box 51 is consistent with the movement of the foot of the AFO patient. The mounting position of the storage box 51 on the triangular swing arm 21 can be adjusted to accommodate the needs of AFO patients with varying foot lengths. A through-hole is defined at the rear end of the bottom wall of the storage box 51, into which the trigger block 53 is located. A cover is secured to the outer end of the storage box 51 with set screws.

[0054] like Figure 6As shown, the displacement transmission mechanism 52 includes two symmetrically arranged and synchronously moving linkages. Each linkage includes a C-shaped rod 5211 fixedly connected to the trigger block 53, a first linkage 5212 rotatably connected to the top end of the C-shaped rod 5211, and a parallelogram mechanism rotatably connected to the other end of the first linkage 5212. A fifth linkage 5216 is rotatably connected to the end of the parallelogram mechanism away from the first linkage 5212, and the other end of the fifth linkage 5216 is rotatably connected to the locking block 541. Specifically, a pin holder is integrally provided on the top surface of the bottom wall of the storage box 51, in front of the edge of the opening. The bottom ends of the two side-by-side C-shaped rods 5211 are rotatably connected to the pin holder via a pin A. The trigger block 53 is also fixedly connected to the bottom ends of the two C-shaped rods 5211. The top ends of the two C-shaped rods 5211 are connected by a pin B. One end of the two first linkages 5212 is sleeved on the pin B, allowing the first linkages 5212 to rotate relative to the C-shaped rods. Two groups of pin seats are integrally provided on the bottom surface of the top wall of the storage box 51. The second link 5213 is rotatably connected to the one group of pin seats via a pin D, and the third link 5214 is rotatably connected to the other group of pin seats via a pin E. The third link 5214 has the same structure as the second link 5213, and the bottom end of the second link 5213 is rotatably connected to one end of the fourth link 5215 via a pin F, and the bottom end of the third link 5214 is rotatably connected to the other end of the fourth link 5215 via a pin G, so that the second link 5213 and the third link 5214 are arranged in parallel, so that the second link 5213, the third link 5214, the fourth link 5215 and the top wall of the storage box 51 constitute the parallel four-bar mechanism. The ends of the two first connecting rods 5212 are rotatably connected via pin C, and the middle portions of the two second connecting rods 5213 are also rotatably connected to pin C. One end of the two fifth connecting rods 5216 is rotatably connected to pin G, and the other end is rotatably connected to pin H. Each pin is fitted with a sleeve to axially position the connecting rod rotatably connected to the corresponding pin. The displacement transmission mechanism 52 converts the swinging displacement generated by the trigger block 53 into the displacement of the fifth connecting rod 5216, which is then transmitted to the first clutch mechanism 54. The two sets of connecting rod mechanisms are symmetrically arranged within the storage box 51 and connected as a whole by a fixed pin, allowing for synchronized movement and enhancing the stability of the displacement transmission.

[0055] like Figure 4 、 Figure 5 and Figure 7As shown, the first clutch mechanism 54 includes a lock block 541 that moves horizontally back and forth, a trigger 544 that is vertically movably inserted into the front end of the bottom of the storage box 51, and a lock post 542 that is fixedly installed on the inner side of the trigger 544. One end of the trigger 544 protrudes below the bottom surface of the storage box 51, and the other end is movably inserted into the bottom wall of the storage box 51 and drives the lock post 542 to lock and unlock the lock block 541. Specifically, a support platform is fixedly installed at the front end of the storage box 51, and a lock post hole is formed on the top surface of the support platform. The lock block 541 is movably installed on the top surface of the support platform. A rectangular groove is formed in the middle of the lock block 541 and is located above the lock post hole. The two sides of the rear end of the lock block 541 are rotatably connected to the two ends of the pin H. The first clutch mechanism 54 also includes a first rolling wheel 546 and a second rolling wheel 547, respectively threadedly connected to either side of the locking block 541. The first rolling wheel 546 and the second rolling wheel 547 roll horizontally on the top surface of the support platform, forming a movable pair between the locking block 541 and the support platform. The top end of the locking post 542 is movable and retractable within the locking post hole. When the locking post 542 extends out of the locking post hole, the locking post 542 is located within the rectangular groove, thereby restricting the horizontal movement of the locking block 541 and placing the first clutch mechanism 54 in a locked state. When the locking post 542 is retracted into the locking post hole, the locking block 541 can move freely horizontally, and the first clutch mechanism 54 is now in an unlocked state. The bottom end of the locking post 542 is threadedly connected to a force block 543, which is located above the bottom wall of the storage box 51. The bottom end of the force block 543 is threadedly connected to the trigger 544. The locking post 542 is also sheathed with a first compression spring 545, which is located between the support platform and the force block 543. The force block 543 and the trigger 544 are both cylindrical boss structures. When the two are connected, they form a cylinder with an "I" cross-section. The cylinder can move vertically within the bottom wall of the storage box 51. The displacement length of the lock column 542, that is, the compression amount of the first compression spring, is determined by the vertical distance between the end faces of the force block 543 and the trigger 544 after connection.

[0056] The upper end of the assist spring 3 is fixedly connected to one side of the top of the leg support mechanism 1 (specifically, the eye bolt 16 ), and the lower end is fixedly connected to the locking block 541 via the first flexible cable 71 .

[0057] like Figure 8 As shown (the direction from top to bottom in the figure corresponds to Figure 1 ), the second clutch device 6 includes a fixed housing 62 fixedly connected to the leg support mechanism 1, an outer end cover 63 fixedly connected to the outer end surface of the fixed housing 62, a first fixed spindle 61 fixedly installed between the fixed housing 62 and the outer end cover 63, and an energy storage and release mechanism 64 installed on the first fixed spindle 61. Specifically, as Figure 8 and Figure 14As shown, the fixed housing 62 is a cylindrical housing structure with an open outer end face. A connecting flange is integrally provided on the side wall of the open end. A number of evenly distributed through holes are provided on the inner end face. The fixed housing 62 is fixedly connected to the first calf side plate 11 by bolt pairs located in the through holes. A wire groove is also provided on the cylindrical side face of the fixed housing 62 for leading out the second flexible cable 72. A cylindrical slot is integrally provided at the center of the inner surface of the inner end side wall of the fixed housing 62 for inserting the first fixed spindle 61. The outer end cover 63 is fixedly mounted on the connecting flange of the fixed housing 62 by screws. Figure 10 As shown, the first fixed spindle 61 is a stepped shaft with a flange at one end. The flange is screwed to the inner end surface of the outer end cap 63, allowing the first fixed spindle 61 to be coaxially fixed within the fixed housing 62 and remain fixed at all times. The other end of the first fixed spindle 61 is inserted into a cylindrical slot in the fixed housing 62. A threaded hole is provided at the axis center of the distal end surface of the first fixed spindle 61, and a through hole is provided at the bottom of the cylindrical slot. A screw located in the through hole is threadedly connected to the threaded hole, thereby fixing the other end of the first fixed spindle 61 to the fixed housing 62.

[0058] The energy storage and release mechanism 64 includes a second clutch mechanism 641 and an energy storage mechanism 642 embedded in the second clutch mechanism 641. The clutch control end of the second clutch mechanism 641 is fixedly connected to the lock block 541 via a third flexible cable 73, and the power execution end of the second clutch mechanism 641 is fixedly connected to the bandage fixed to the toe via a second flexible cable 72. Figure 8 As shown, the second clutch mechanism 641 includes a one-way drive wheel 6411 rotatably mounted on the first fixed spindle 61, a locking pin 6412 engaged and disengaged with the one-way drive wheel 6411, and a cylindrical pin holder 6414 fixedly mounted on the first fixed spindle 61 and located between the one-way drive wheel 6411 and the outer end cap 63. The cross-section of the shaft of the first fixed spindle 61 near its flange is non-circular. A through-hole matching the cross-sectional shape of the shaft section is defined at the axis of the cylindrical pin holder 6414. This through-hole engages with the shaft section to achieve circumferential positioning of the cylindrical pin holder 6414 on the first fixed spindle 61. The inner end surface of the cylindrical pin holder 6414 is secured axially by a shaft retaining ring 6416 engaged with the first fixed spindle 61.

[0059] like Figure 11 and Figure 13As shown, a bearing mounting hole is provided on the end face of the one-way transmission wheel 6411 near the cylindrical pin seat 6414, and a second rolling bearing 6425 is embedded in the bearing mounting hole. The second rolling bearing 6425 is sleeved on the first fixed spindle 61; a bearing seat 6423 is fixedly connected to the inner end face of the one-way transmission wheel 6411 by screws, and a first rolling bearing 6424 is embedded in the bearing seat 6423. The first rolling bearing 6424 is sleeved on the first fixed spindle 61, so that the one-way transmission wheel 6411 is rotatably mounted on the first fixed spindle 61 and located on the inner side of the cylindrical pin seat 6414. Figure 11 and Figure 13 As shown, the end surface of the one-way drive wheel 6411 near the locking pin 6412 is provided with one-way drive grooves evenly distributed around the circumference, and the depth of the one-way drive grooves gradually decreases along the rotation direction of the one-way drive wheel 6411. A guide hole parallel to the axis of the cylindrical pin seat 6414 is provided on one side of the end surface. One end of the locking pin 6412 is movably inserted into the guide hole of the cylindrical pin seat 6414, allowing the locking pin 6412 to move axially under the action of the guide hole and detachably engage into the one-way drive groove. When the locking pin 6412 is completely separated from the one-way drive groove, the one-way drive wheel 6411 is in a free rotation state. When the locking pin 6412 is movably inserted into the one-way drive groove, the one-way drive wheel 6411 can only rotate in a counterclockwise direction due to the blocking of the locking pin 6412 against the side wall of the one-way drive groove. To ensure that the locking pin 6412 can be automatically inserted into the one-way transmission groove, a second compression spring 6413 is sleeved on the locking pin 6412. A cylindrical pin seat 6414 is fixedly connected to a support seat 6415 near the outer end cover. One end of the second compression spring 6413 contacts the inner wall of the support seat 6415, and the other end contacts the boss on the locking pin 6412. When the one-way transmission wheel 6411 rotates counterclockwise, the bottom surface of the one-way transmission groove pushes the locking pin 6412 to move axially until the end of the locking pin 6412 is located on the end surface of the one-way transmission wheel 6411 and slides relative to the end surface of the one-way transmission wheel 6411. At this time, the second compression spring 6413 is in a compressed state. When the locking pin 6412 reaches the position of the next one-way transmission groove, the second compression spring 6413 automatically returns to its original position, pushing the locking pin 6412 into the one-way transmission groove.

[0060] The tail of the locking pin 6412 has a hole and is fixedly connected to the third flexible cable 73. A strip-shaped through-slot is defined on the top wall of the storage box 51, directly above the locking block 541. The other end of the third flexible lock 73 passes through the strip-shaped through-slot and is fixedly connected to the locking block 541, thus achieving linkage between the first clutch 5 and the second clutch 6. A cable groove is defined on the cylindrical surface of the one-way transmission wheel 6411. One end of the second flexible cable 72 is fixedly connected to the groove wall of the cable groove and partially wrapped within the cable groove. The other end passes through the cable groove on the cylindrical side of the fixed housing 62 and is fixedly connected to the bandage fixed to the toe area.

[0061] like Figure 8 As shown, the energy storage mechanism 642 includes a coil spring fixing bracket 6421 sleeved on the first fixed spindle 61 and embedded in the one-way transmission wheel 6411, a coil spring 6422 connected between the first fixed spindle 61 and the coil spring fixing bracket 6421, and a bearing seat 6423 located outside the coil spring fixing bracket 6421 is fixedly connected to the end surface of the one-way transmission wheel 6411. Specifically, a rectangular groove is formed on the circumferential surface of the first fixed spindle 61, and the inner hook of the coil spring 6422 is hooked with the rectangular groove (as shown in FIG. Figure 10 As shown), a circular embedding groove is provided on the end surface of the one-way transmission wheel 6411 away from the cylindrical pin seat 6414, and two lateral embedding grooves are provided on the side wall of the circular embedding groove (as shown Figure 9 and Figure 12 As shown), the coil spring fixing bracket 6421 is a circular ring structure, the outer surface of which is integrally provided with a lateral protrusion that matches the lateral embedding groove, and the inner surface of which is provided with a through groove (as shown Figure 9 As shown, the lateral protrusions engage with the lateral grooves, securing the coil spring retaining bracket 6421 within the one-way drive wheel 6411. The bearing seat 6423 blocks the coil spring retaining bracket 6421 from axial movement. The outer hook of the coil spring 6422 engages with the through-slot in the coil spring retaining bracket (6421).

[0062] In order to realize the directional transmission of each flexible cable, the ankle-foot orthosis based on the passive dual clutch also includes a pulley guide mechanism, which includes a first pulley guide mechanism 81 fixedly arranged on the rear end surface of the storage box 51, a second pulley guide mechanism 82 fixedly arranged on the lower leg support 15, and a third pulley guide mechanism 83 fixedly arranged on the outer end cover 63. The first flexible cable 71 passes around the second pulley guide mechanism 82 and the first pulley guide mechanism 81 in turn, and the third flexible cable 73 passes around the third pulley guide mechanism 83.

[0063] The working principle and process of the ankle-foot orthosis based on the passive dual clutch are as follows:

[0064] During normal walking, the movement of the lower limbs has a certain regularity and periodicity, so the movement of the lower limbs can be planned as a single gait cycle; a single gait cycle starts with the heel of one leg touching the bottom and ends with the next heel touching the bottom; depending on whether the sole of the foot is in contact with the ground, the gait cycle can be divided into a support period and a swing period. In a complete gait cycle, the functions provided by the ankle-foot orthosis based on the passive dual clutch are divided into two stages: one is to provide assistance during the support period, corresponding to the first clutch device 5; the other is to prevent the patient's foot from dropping during the swing period, corresponding to the second clutch device 6. This device is suitable for stroke patients who still have partial walking ability, specifically, stroke patients who have lost dorsiflexion ability but still have a certain plantar flexion ability. Before use, the patient first puts on the exoskeleton, assists the patient's toes to be slightly upturned, and rotates the one-way transmission wheel 6411 through the wire groove opened on the fixed shell 62 to pre-tighten the coil spring 6422 and tighten the second flexible cable 72.

[0065] 1. Support during the support period:

[0066] The function of the first clutch device 5 is to provide assistance to the patient, and its action mechanism is as follows: in the initial stage of support, the trigger block 53 touches the ground and generates displacement, and the movement is transmitted to the moving pair through the displacement transmission mechanism 52, causing the locking block 541 to move forward, and the first flexible cable 71 fixed to the locking block 541 stretches the assisting spring 3 to generate a certain elastic potential energy; in the middle stage of support, the trigger 544 at the front foot touches the ground and generates displacement, and the upper locking column 542 moves upward to insert into the rectangular groove of the locking block 541 and limit the displacement of the locking block. At this time, the first compression spring 545 is compressed, and the energy of the assisting spring 3 is stored. As the calf swings forward relative to the ankle joint, the assisting spring 3 will be stretched for the second time, thereby increasing the stored energy of the assisting spring 3; in the late stage of support, as the heel is lifted, the energy in the assisting spring 3 is released, providing assistance to the patient; when the trigger 544 leaves the ground, the first clutch device 5 returns to its initial state under the recovery of the first compression spring 545 and the assisting spring 3;

[0067] 2. Prevent foot drop during the swing phase:

[0068] The function of the second clutch device 6 is to correct the abnormal gait of foot drop caused by hemiplegic patients during the swing phase. Its working mechanism is as follows: in the early stage of support, when the locking block 541 moves forward, it also pulls the third flexible cable 73 to separate the locking pin 6412 from the one-way transmission wheel 6411. At this time, the second compression spring 6413 is compressed, and the one-way transmission wheel 6411 can rotate freely; in the late stage of support, when the ankle joint performs plantar flexion, the second flexible cable 72 pulls the one-way transmission wheel 6411 to rotate clockwise, and the coil spring 6413 is compressed. 422 curls up to store energy; when the moving pair returns to its initial position, the locking pin 6412 fixedly connected to the third flexible cable 73 is locked in one direction with the one-way transmission wheel 6411; in the early stage of swinging, the coil spring 6422 releases energy to make the one-way transmission wheel 6411 rotate counterclockwise, and the second flexible cable 72 lifts the toes to prevent the foot from dropping, and because the one-way transmission wheel 6411 cannot rotate clockwise under the action of the locking pin 6412, the lifted state of the foot can be maintained throughout the swinging period.

[0069] A correction method for an ankle-foot orthosis based on a passive dual-clutch corresponding to the above-mentioned working mechanism includes the following steps:

[0070] S10. The ankle-foot orthosis patient wears and fixes the passive double-clutch ankle-foot orthosis on the calf and foot, and walks with support.

[0071] S20, at the initial stage of foot contact, the trigger block 53 touches the ground and swings upward, causing the locking block 541 to translate forward via the displacement transmission mechanism 52. The first flexible cable 71 connected to the locking block 541 stretches the assist spring 3 to generate elastic potential energy.

[0072] When the locking block 541 translates forward, it also pulls the third flexible cable 73 to separate the locking pin 6412 from the one-way transmission wheel 6411. The second compression spring 6413 is compressed, and the one-way transmission wheel 6411 is in a free rotation state.

[0073] S30, in the middle stance phase, the trigger 544 at the front foot touches the ground and moves upward, the locking post 542 moves upward and inserts into the locking block 541, locking the first clutch mechanism 54. The energy of the assist spring 3 is stored, and the first compression spring 545 is compressed.

[0074] The calf swings forward relative to the ankle joint, which stretches the assist spring 3 a second time, thereby increasing the energy storage capacity of the assist spring 3;

[0075] S40: In the later stage of support, as the heel is lifted, the distance between the top of the assisting spring 3 and the bottom of the first flexible cable 71 becomes shorter, and the energy in the assisting spring 3 is released to assist the patient's foot.

[0076] When the ankle joint performs plantar flexion, the second flexible cable 72 pulls the one-way transmission wheel 6411 to rotate clockwise, causing the coil spring 6422 to curl and store energy. When the plantar flexion ends, the trigger 544 is lifted off the ground. Under the restoring action of the first compression spring 545, the first clutch mechanism 54 is unlocked. Under the restoring action of the second compression spring 6413, the locking pin 6412 is locked with the one-way transmission wheel 6411, so that the one-way transmission wheel 6411 can only transmit in one direction.

[0077] S50. In the initial swing phase after the calf is lifted, the coil spring 6422 releases energy to rotate the one-way drive wheel 6411 counterclockwise. The second flexible cable 72 is reeled in to lift the toes to prevent them from sagging. The one-way drive wheel 6411 cannot rotate clockwise due to the locking pin 6412, so that the foot remains in the lifted toes position.

[0078] S60, repeating steps S20 to S50 to complete the ankle-foot orthosis process for the ankle-foot orthosis patient;

[0079] S70: After the correction is completed, the passive dual-clutch ankle-foot orthosis is removed from the lower leg and foot of the ankle-foot orthosis patient.

[0080] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An ankle-foot orthosis based on a passive dual-clutch, characterized by: The invention comprises a leg support mechanism (1) fixed to both sides of the calf by means of a strap (4), a rotating pair (2) rotatably connected to the bottom of the leg support mechanism (1), a booster spring (3) arranged parallel to the calf, a first clutch device (5) fixedly connected to the outer side of the bottom of the rotating pair (2), and a second clutch device (6) fixedly connected to the outer side of the leg support mechanism (1); The first clutch device (5) comprises a storage box (51) fixedly arranged on the side of the sole of the foot, a displacement transmission mechanism (52) arranged inside the storage box (51), a trigger block (53) fixedly connected to the power input end of the displacement transmission mechanism (52), a first clutch mechanism (54) rotatably connected to the power output end of the displacement transmission mechanism (52), and a cover plate (55) fixedly connected to the storage box (51); the trigger block (53) is hinged to the rear end of the bottom surface of the storage box (51) and can move in and out of the storage box (51); The first clutch mechanism (54) comprises a locking block (541) that moves horizontally back and forth, a trigger (544) that is vertically movable and inserted at the front end of the bottom of the storage box (51), and a locking column (542) that is fixedly arranged on the inner side end of the trigger (544), one end of the trigger (544) protruding below the bottom surface of the storage box (51), and the other end of the trigger (544) being movable and inserted into the bottom wall of the storage box (51) and driving the locking column (542) to lock and unlock the locking block (541); The upper end of the assist spring (3) is fixedly connected to one side of the top of the leg support mechanism (1), and the lower end is fixedly connected to the locking block (541) via a first flexible rope (71); The second clutch device (6) comprises a fixed shell (62) fixedly connected to the leg support mechanism (1), an outer end cover (63) fixedly connected to the outer end surface of the fixed shell (62), a first fixed spindle (61) fixedly installed between the fixed shell (62) and the outer end cover (63), and an energy storage and release mechanism (64) installed on the first fixed spindle (61). The energy storage and release mechanism (64) comprises a second clutch mechanism (641) and an energy storage mechanism (642) embedded in the second clutch mechanism (641). The clutch control end of the second clutch mechanism (641) is fixedly connected to the locking block (541) via a third flexible cable (73), and the power execution end of the second clutch mechanism (641) is fixedly connected to a bandage fixed to the toe portion via a second flexible cable (72).

2. The ankle-foot orthosis based on a passive dual clutch according to claim 1, characterized in that: The leg support mechanism (1) comprises a first calf side plate (11) attached to the outside of the calf and placed vertically, a second calf side plate (12) attached to the inside of the calf and parallel to the first calf side plate (11), and an adjustment connecting plate (13) that can be slidably adjusted and connected to the bottom of the first calf side plate (11), wherein the top and bottom of the first calf side plate (11) and the second calf side plate (12) are respectively fixedly connected to a calf upper bracket (14) and a calf lower bracket (15) both located on the back of the calf, and a side of the calf upper bracket (14) is fixedly connected to a lifting eye bolt (16).

3. The ankle-foot orthosis based on a passive dual clutch according to claim 2, characterized in that: The rotating pair (2) comprises a triangular swing rod (21), a second fixed spindle (22) connected to the top of the triangular swing rod (21), the second fixed spindle (22) being sleeved on the bottom of the adjustment connecting plate (13), and a strip-shaped through hole being opened on the bottom section of the triangular swing rod (21).

4. The ankle-foot orthosis based on a passive dual clutch according to claim 1, characterized in that: The displacement transmission mechanism (52) comprises two groups of symmetrically arranged and synchronously moving link mechanisms, each link mechanism comprising a C-shaped rod (5211) fixedly connected to the trigger block (53), a first link (5212) rotatably connected to the top end of the C-shaped rod (5211), and a parallelogram mechanism rotatably connected to the other end of the first link (5212), wherein one end of the parallelogram mechanism away from the first link (5212) is rotatably connected to a fifth link (5216), and the other end of the fifth link (5216) is rotatably connected to the locking block (541).

5. An ankle-foot orthosis based on a passive dual clutch according to any one of claims 1 to 4, characterized in that: The first clutch mechanism (54) further comprises a first rolling wheel (546) and a second rolling wheel (547) respectively threadedly connected to both sides of the locking block (541); a support platform is fixedly provided at the inner front end of the storage box (51); the first rolling wheel (546) and the second rolling wheel (547) roll horizontally on the top surface of the support platform; a through locking column hole is provided on the top surface of the support platform; the top end of the locking column (542) can be movably extended and retracted in the locking column hole; the bottom end of the locking column (542) is threadedly connected to a force block (543); the force block (543) is located above the bottom wall of the storage box (51); and the bottom end of the force block (543) is threadedly connected to the trigger (544); the locking column (542) is also sleeved with a first compression spring (545) located between the support platform and the force block (543).

6. An ankle-foot orthosis based on a passive dual clutch according to any one of claims 1 to 4, characterized in that: The second clutch mechanism (641) comprises a one-way transmission wheel (6411) rotatably sleeved on the first fixed spindle (61), a locking pin (6412) in a clutch relationship with the one-way transmission wheel (6411), and a cylindrical pin seat (6414) fixedly sleeved on the first fixed spindle (61) and located between the one-way transmission wheel (6411) and the outer end cover (63); a one-way transmission groove uniformly distributed on the circumference is provided on the end surface of the one-way transmission wheel (6411) close to the locking pin (6412); one end of the locking pin (6412) is movably inserted into the cylindrical pin seat (6414) and detachably embedded in the one-way transmission groove; the other end of the locking pin (6412) is fixedly connected to the third flexible cable (73); a wire groove is provided on the wheel cylindrical surface of the one-way transmission wheel (6411), and one end of the second flexible cable (72) is wound in the wire groove.

7. The ankle-foot orthosis based on the passive dual clutch according to claim 6, characterized in that: A second compression spring (6413) is sleeved on the locking pin (6412), and the cylindrical pin seat (6414) is fixedly connected to a support seat (6415) near the outer end cover side. The cylindrical pin seat (6414) is axially positioned by a shaft retaining ring (6416).

8. The ankle-foot orthosis based on a passive dual clutch according to claim 6, characterized in that: The energy storage mechanism (642) comprises a coil spring fixing bracket (6421) sleeved on the first fixed spindle (61) and embedded in the one-way transmission wheel (6411), a coil spring (6422) connected between the first fixed spindle (61) and the coil spring fixing bracket (6421), and a bearing seat (6423) located outside the coil spring fixing bracket (6421) is fixedly connected to the end face of the one-way transmission wheel (6411).

9. The ankle-foot orthosis based on a passive dual clutch according to claim 2, characterized in that: The invention also includes a pulley guide mechanism (8), wherein the pulley guide mechanism (8) includes a first pulley guide mechanism (81) fixedly arranged on the rear end surface of the storage box (51), a second pulley guide mechanism (82) fixedly arranged on the lower leg bracket (15), and a third pulley guide mechanism (83) fixedly arranged on the outer end cover (63), wherein the first flexible cable (71) passes through the second pulley guide mechanism (82) and the first pulley guide mechanism (81) in sequence, and the third flexible cable (73) passes through the third pulley guide mechanism (83).

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