Lower extremity exoskeleton

Abstract

A lower limb exoskeleton includes a trunk module (20) comprising an adjustable abdominal band (22) and two lower limb assemblies (10) connected to the trunk module (20) via hip joints (21). Each lower limb assembly (10) includes a thigh module (11), a knee joint (12), a calf module (13), and a lower support footrest (15). Each lower limb assembly (10) also includes a knee actuation mechanism (40), which includes a push rod (42) slidably connected to the calf module. When the push rod (42) is not in its uppermost position, its lower end (42b) protrudes downward below the lower support footrest (15), and its upper end (42a) is connected to the thigh module (11) via a motion linkage mechanism configured to push the thigh module (11) into an extended position when the push rod (42) moves upward against the ground due to the user's body weight.

Description

Technical Field

[0001] This invention relates to a lower limb exoskeleton designed to assist patients who are unable to walk normally, injured persons, or persons who must carry heavy objects or maintain an upright posture for extended periods under specific circumstances. Background Technology

[0002] Lower limb exoskeletons are known in the prior art, for example, through documents EP2326288B1, EP3313350B1 or EP3538030B1.

[0003] These documents describe different solutions, some of which are motorized and provide walking assistance for people with mobility difficulties.

[0004] However, the solutions proposed in these documents do not provide a simple, reliable, and low-cost system that prevents unintentional bending of the knee joint when weight is applied to the leg through its mechanical solution.

[0005] The aforementioned literature also failed to address the issue of how to attach the exoskeleton to the user's body in a comfortable and safe manner during prolonged use, i.e., allowing the transfer of most of the user's weight to the exoskeleton without relying on straps located in the groin area, where the pressure from these straps could compress veins and arteries, thereby increasing the risk of vascular accidents such as thrombosis.

[0006] This invention provides solutions to these and other problems. Summary of the Invention

[0007] The present invention relates to a lower limb exoskeleton as defined in claim 1, which is designed to support the weight by transferring most of the user's body weight to the ground via the lower limb exoskeleton, thereby ensuring that the user does not have to support the entire weight with legs that may be unable to support the weight due to age, disease or injury, or simply to reduce fatigue or avoid injury.

[0008] The proposed lower limb exoskeleton includes:

[0009] The trunk module includes an adjustable abdominal binder and two lower limb components connected to the trunk module via hip joints. Each lower limb component includes a thigh module, a knee joint, a calf module, and a lower support footrest connected in sequence, wherein the hip joint and the knee joint are hinged joints.

[0010] Each limb component also includes a knee actuation mechanism configured to change the angle of the knee joint when actuated.

[0011] At least the thigh module and the calf module include at least one body attachment structure for attaching to a part of the user's body adjacent to the thigh module.

[0012] The torso module is designed to attach around the user's torso via the aforementioned adjustable abdominal binder. The adjustable abdominal binder typically consists of a textile strap with hook and loop fasteners (Velcro or similar products).

[0013] Each lower limb assembly includes a thigh module and a lower leg module articulated together via a knee joint, allowing the thigh and lower leg modules to move between an extended position and a flexed position. In the extended position, the thigh and lower leg modules are generally parallel or aligned, typically forming an angle between 170° and 180°. In the flexed position, the thigh and lower leg modules form an angle less than 170°, typically between 170° and 90°.

[0014] The knee joint is hinged around a single transverse axis that is roughly horizontal and perpendicular to the sagittal plane.

[0015] Each lower limb component is connected to the trunk module via a hip joint that is hinged at least around a transverse axis that is generally horizontal and perpendicular to the sagittal plane, and preferably includes one or two additional degrees of freedom, for example by including a ball-and-socket joint in the hip joint, or by including a hinge between the hip joint and at least a portion of the thigh module that is hinged around an axis perpendicular to the thigh module.

[0016] All positions and orientations, such as front, back, up, down, vertical, horizontal, lateral, or other geometric references (e.g., the sagittal plane), should be understood as the orientation of the lower limb exoskeleton being consistent with the user's reference orientation relative to the hypothetical state of the user wearing the exoskeleton in an upright position. The coordinate system proposed accordingly has an anterior axis that runs from the user's front to their rear, and a lateral axis that is perpendicular to the anterior axis and runs from one side of the user to the opposite side. Similarly, it should be understood that positional terms such as parallel, perpendicular, and tangent are allowed to deviate from the theoretical position defined by the term by ±5°.

[0017] The lower support footrest is located at the bottom of the lower limb assembly and is designed to support the user's legs on the ground to transfer vertical loads to the floor, thereby reducing the load on the user's legs.

[0018] The present invention also proposes the following:

[0019] The knee actuation mechanism includes a push rod with a central region slidably connected to the calf module for guiding linear movement of the push rod along a linear displacement path. The push rod includes a lower end that protrudes downward below the lower support footrest when the push rod is not at the uppermost position of the linear displacement path. The push rod also includes an upper end connected to the thigh module via a motion linkage mechanism configured to push the thigh module into an extended position when the push rod moves upward under the user's body weight due to its lower end abutting the ground.

[0020] To prevent uncontrolled bending of the knee joint when weight is transferred through the lower limb components, thereby blocking weight transfer, the knee joint includes a knee joint actuation mechanism.

[0021] The knee joint actuation mechanism includes a push rod that is typically parallel to the lower leg module and is slidably attached to the lower leg module, allowing the push rod to slide up and down along the lower leg module.

[0022] The upper end of the push rod is kinematically connected to the thigh module, and the connection is configured to generate a downward movement of the push rod when the limb assembly bends from an extended position to a flexed position.

[0023] When the push rod is in its highest position (referred to as the extended position), the lower end of the push rod is flush with the lower support footrest, and when the push rod is pushed down due to the bending of the lower limb assembly, the lower end of the push rod protrudes downward from the lower support footrest.

[0024] Therefore, when the lower limb component bends in a certain way (e.g., during walking), the lower end of the push rod protrudes downward and contacts the ground before the lower support footrest. The user's weight acts on the push rod, causing it to move upward, resulting in the extension movement of the lower leg component, until the lower support footrest contacts the ground, stopping the upward movement of the push rod.

[0025] In a similar manner, as the user bends their knee, the push bar moves downward, helping to lift the foot off the ground.

[0026] In this way, thanks to the knee joint actuation mechanism, during the user's walking motion, when the weight is supported by a single leg, the weight supported by that leg prevents the knee from bending because the push rod cannot move downwards against the ground, thus preventing accidental bending of that leg when all the weight is transmitted through the lower leg assembly. At the same time, the other unweighted leg can bend freely, and the foot can be lifted from the ground.

[0027] Preferably, the torso module includes two underarm supports, each extending upward from a hip joint.

[0028] An underarm support is a support device designed to be placed under a user's armpit. Typically, underarm supports will have an upward arch or saddle shape to provide support under the user's arm and may include some cushioning padding.

[0029] The underarm support, together with the adjustable abdominal binder, transfers most of the user's weight to the hip joint and lower limb components, which then transfer this weight to the lower support footrest, relieving the user's legs of the weight.

[0030] Optionally, the two underarm supports can be used in conjunction with two shoulder straps connected to the torso module to prevent excessive shoulder elevation when weight is transferred through the underarm supports.

[0031] The two underarm supports located below the arms help the adjustable abdominal belt support part of the body's weight. At the same time, the adjustable abdominal belt includes two shoulder straps that pass through the shoulders and fix the shoulder height so that the underarm supports, which are designed to support part of the body's weight, do not raise the shoulders higher than usual.

[0032] As a complement or alternative to the two shoulder straps, the two underarm supports can be further combined with the hip supports that extend downwards from the back of the adjustable abdominal band.

[0033] The under-hip support is a small, concave support, similar to a high chair, designed to accommodate the user's hips and provide a holding force against upward movement for the torso module.

[0034] Preferably, the under-hip support is made of textile and includes a transverse strap along its bottom edge, extending from both transverse sides of the under-hip support. The extended portion of the strap can be attached to the front area of ​​an adjustable abdominal band to adjust the concave shape and size of the under-hip support to fit the user.

[0035] Based on the above, the lateral strap of the under-hip support wraps around the user from below the hips to the abdomen or above, and the lateral side of the lateral strap has an angle of approximately 40° to 50° relative to the horizontal plane.

[0036] Adjustable abdominal binders may also include vertical reinforcing ribs, for example on their back, preferably along the lumbar region. These vertical reinforcing ribs can better distribute the load around the user's torso.

[0037] Preferably, the torso module does not have groin straps connecting the rear and front sides of the adjustable abdominal binder. The user's groin area is a very sensitive area and contains many important arteries, veins, and nerves, and these arteries, veins, and / or nerves may be compressed and injured during prolonged use of the groin strap.

[0038] The trunk module proposed in this invention can eliminate the need for a groin belt by using the aforementioned adjustable abdominal binder (which wraps around the trunk and distributes the load, distributing pressure to the largest surface of the user's trunk), and optionally also using underarm and hip supports. This avoids the use of a groin belt that goes around the upper part of the legs and through the groin area, thereby avoiding compression of the femoral vein and avoiding possible injuries such as "stroke" or infarction. Attached Figure Description

[0039] The foregoing and other advantages and features will be more fully understood through the following detailed description of the embodiments and with reference to the accompanying drawings, which should be interpreted in an illustrative and non-limiting manner, wherein:

[0040] Figure 1 A side view of the proposed lower limb exoskeleton in an extended position according to the first embodiment is shown, wherein the lower support footrest is footwear (boots in this example), and wherein the torso module includes two underarm supports, two shoulder straps and a hip support.

[0041] Figure 2 The same side view is shown, but the lower limb components are in a bent position.

[0042] Figure 3 It shows the relationship with Figure 1 The same lower limb exoskeleton is shown, but presented in a front view.

[0043] Figure 4 A front view of a limb exoskeleton according to an alternative embodiment is shown, wherein the lower support footrest is a stirrup that can be attached to the user's footwear.

[0044] Figure 5 A front view of a limb exoskeleton according to another alternative embodiment is shown, wherein the knee joint actuation mechanism further includes a linear motor, one end of which is connected to the thigh module and the other end to the calf module. Detailed Implementation

[0045] The proposed lower limb exoskeleton includes a trunk module 20 and two lower limb components 10. The trunk module 20 includes an adjustable abdominal band 22, and the lower limb components 10 are connected to the trunk module 20 via hip joints 21.

[0046] Each limb component 10 includes a thigh module 11, a knee joint 12, a lower leg module 13, and a lower support footrest 15 connected in sequence. The hip joint 21 and the knee joint 12 are joints hinged around at least one transverse axis perpendicular to the sagittal plane of the user wearing the lower limb exoskeleton.

[0047] Each limb component 10 also includes a knee actuation mechanism 40, which is configured to change the angle of the knee joint 12 when actuated.

[0048] At least the thigh module 11 and the calf module 13 include at least one body attachment structure 30, which is designed to attach to a body part adjacent to the user, for example using a textile strap or other adjustable system with hook and loop fasteners (Velcro or similar).

[0049] The proposed knee actuation mechanism 40 includes a push rod 42 having a central region slidably connected to the lower leg module 13 for guiding linear movement of the push rod 42 along a linear displacement path. The push rod 42 includes a lower end 42b that protrudes downward below the lower support footrest 15 when the push rod 42 is not in the uppermost position of the linear displacement path, and the push rod 42 includes an upper end 42a connected to the thigh module 11 via a motion linkage mechanism configured to push the thigh module 11 into an extended position when the push rod 42 moves upward under the user's body weight due to its lower end 42b abutting against the ground.

[0050] The torso module 20 may include two underarm supports 23, each extending upward from a hip joint 21, and optionally in conjunction with two shoulder straps 24 and / or a hip support 25 extending downward from the rear of an adjustable abdominal band 22.

[0051] Preferably, the under-hip support 25 is made of textile and includes a transverse strap 26 along its bottom edge, the strap 26 extending from both transverse sides of the under-hip support 25. The extended portion of the transverse strap 26 can be attached to the front region of an adjustable abdominal band 22 to adjust the concave shape and size of the under-hip support 25 to fit the user.

[0052] The adjustable abdominal band 22 may also include vertical reinforcing ribs to better distribute the load around the user's torso.

[0053] Preferably, the torso module 20 does not require a groin strap connecting the rear and front sides of the adjustable abdominal binder 22. A groin strap that crosses the groin area between the user's legs can be harmful, and avoiding its use is beneficial. The function provided by the groin strap can be replaced by the underarm support 23 and / or the hip support 25.

[0054] According to one embodiment of the invention, each underarm support can be connected to the underlying hip joint via an incompressible connector or a flexible incompressible connector. Optionally, the incompressible connector is a flexible connector, such as an axially contracting spring 27, wherein each ring is on top of the preceding ring, or two nested, axially contracting reversible springs, wherein each ring is on top of the preceding ring.

[0055] Optionally, the length of the connection between each of the calf module 13, thigh module 11, push rod 42, and each axillary support and the corresponding hip joint 21 can be adjusted by length adjustment devices 60, 61, 62, 63, 64 or telescopic length adjustment devices 60, 61, 62, 63, 64 included therein.

[0056] Thanks to the length adjustment devices 60, 61, 62, 63, and 64, the lower limb exoskeleton can easily adapt to each user's height by adjusting the lengths of the calf module 13 and thigh module 11, the length of the push rod 42, and the distance between the underarm support and the hip joint.

[0057] The length adjusting devices 60, 61, 62, 63, and 64 may be formed, for example, by a telescopic structure, having two mutually sliding portions that can be held in relative positions by a retainer such as a transverse pin, or having two threaded portions that can be lengthened or shortened by rotating relative to each other.

[0058] According to the embodiment shown in the figure, the distance between the underarm support 23 and the hip joint 21 is adjusted by a first length adjustment device 60. This first length adjustment device 60 includes a screw with the coil of an axially contracting spring 27 as a thread. The screw is screwed around the spring 27, which serves as a flexible, incompressible connector. The screw acts as an adjustable stop to adjust the depth to which the axially contracting spring 27 is inserted into the housing in the vertical direction.

[0059] In this embodiment, the length of the thigh module 11 can be adjusted by a second length adjustment device 61. The second length adjustment device 61 includes two interlocking portions connected by a pin, one of which includes a plurality of openings for the pin at different longitudinal positions.

[0060] The length of push rod 42 can be adjusted by a threaded telescopic element inserted between the lower end 42b and the rest of push rod 42.

[0061] The length of the calf module 13 can be adjusted by connecting the lower support footrest 15 to different positions along the longitudinal direction of the calf module 13, i.e., connecting it to different perforations distributed along the calf module 13.

[0062] According to one proposed embodiment, the motion linkage between the upper ends 42a of the push rod 42 includes a bending guide 41 attached to the lower end of the thigh module 11 adjacent to the knee joint 12. The bending guide 41 extends from a first end 41a to a second end 41b, defining a trajectory from the first end 41a to the second end 41b, wherein the continuous points of the bending guide 41 gradually move away from the knee joint 12, and the upper ends 42a of the push rod 42 are slidably connected to the bending guide 42.

[0063] Preferably, the continuous points of the bending guide 41 from the first end 41a to the second end 41b form a decreasing acute angle relative to the straight line connecting each of the continuous points and the knee joint 12.

[0064] As described above, for example, when the limb assembly is in the maximum flexed position, the upper end 42a of the push rod 42 is close to the first end 41a of the bending guide 41 and defines an acute angle preferably between 70° and 80°, and / or when the limb assembly is in the maximum extended position, the upper end 42a of the push rod 42 is close to the second end 41b of the bending guide 41 and defines an acute angle preferably between 40° and 30°.

[0065] As described above, the knee joint actuation mechanism includes a curved guide 41 attached to the lower end of the thigh module 11, which is preferably coplanar with a vertical plane perpendicular to the transverse axis of the knee joint 12.

[0066] The knee joint actuation mechanism also includes a push rod 42, which may be a rod that extends vertically, is typically parallel to the lower leg module 13 and is longer than the lower leg module 13.

[0067] The push rod 42 protrudes upward from the upper end of the lower leg module 13, passes over the knee joint 12, and protrudes downward below the lower support footrest 15.

[0068] The middle region of the push rod 42 is slidably connected to the lower leg module 13, allowing the push rod 42 to perform linear guided movement only in the linear guide direction, which is vertical when the lower leg module 13 is in the vertical position.

[0069] According to the above embodiment, the upper end 42a of the push rod 42 is slidably connected to the bending guide 41, so that when the angle of the knee joint 12 changes, causing the bending guide 41 to rotate relative to the lower leg module 13 and the push rod 42 connected thereto, the upper end 42a of the push rod 42 is forced to slide along the bending guide 41, pushing the push rod 42 to move in a linear direction (upward or downward), causing the lower end 42b of the push rod 42 to protrude downward by an increase or decrease in length.

[0070] When a limb component is partially bent, the lower end 42b of the push rod 42 protrudes downward, so that when the user's weight acts on the leg, the lower end 42b contacts the ground and is pushed upward under the weight. The upward movement of the push rod 42 causes its upper end 42a to move upward, creating a sliding between the upper end 42a and the bending guide 41 when interacting with it, pushing the bending guide 41 to a new position that corresponds to the new position of the push rod 42, thus rotating the knee joint 12 toward the extended position.

[0071] To achieve this result, the bending guide 41 is gradually moved away from the knee joint 12, such that the continuous straight line connecting the knee joint 12 and the continuous points of the bending guide 41 gradually increases in length from the first end 41a closer to the knee joint 12 toward the second end 41b further away from the knee joint 12.

[0072] The upward movement of push rod 42 causes an increase in the length of the portion of push rod 42 protruding upward from knee joint 12, forcing the bending guide 41 to rotate toward the second end 41b to accommodate this increase in length.

[0073] Furthermore, each of the continuous straight lines intersects the curved guide 41 at a point, defining an acute angle that gradually decreases from the first end 41A to the second end 41b.

[0074] This acute angle determines how the upward force generated by the push rod 42 is distributed between the rotation of the knee joint 12 and the sliding of the push rod 42 on the bending guide 41.

[0075] When the upper end 42a of the push rod 42 is closer to the first end 41a of the bending guide 41, the acute angle is larger, preferably between 70° and 80°, causing most of the upward force of the push rod 42 to push the bending guide 41 upward.

[0076] Conversely, when the upper end 42a of the push rod 42 is closer to the second end 41b of the bending guide 41, the acute angle is smaller, preferably between 40° and 50°, resulting in only half of the upward force of the push rod 42 pushing the bending guide 41 upward.

[0077] The knee joint actuation mechanism 40 may also include a linear motor 43, one end of which is connected to the thigh module 11 at a position adjacent to the second end 41b of the bending guide 41, and the opposite end is connected to the calf module 13 at a position adjacent to the knee joint 12.

[0078] The increased length of the linear motor 43 causes the lower limb assembly 10 to move toward the extended position.

[0079] In this configuration, the knee actuation mechanism 40 may integrate a sensor configured to detect changes in tilt between the thigh module 11 and the lower leg module 13, or to detect changes in the linear position of the push rod 42, or to detect pressure on the second end 42b of the push rod 42, wherein the linear motor 43 is configured to be activated in response to the detection obtained by the sensor.

[0080] The limb assembly 10 may also include a hand-assist system 50, which includes a drive rod 51 (optionally, the length of the drive rod 51 is adjustable), the lower end of which is attached to the lower leg module 13 via a connector, and the upper end of which has a handle 52 slidably connected to the thigh module 11 for guiding the handle 52 to move linearly along the thigh module 11, and further pushing the lower limb assembly 10 to an extended position by the user applying a downward force on the handle 52 with his / her hand.

[0081] According to one embodiment, the lower support footrest 15 may include a foot module connected to the lower end of the calf module 13 via an inserted hinged ankle joint 14 (e.g., a ball joint).

[0082] For example, the foot module can be a shoe or a stirrup that can be attached to the shoe.

Claims

1. A lower limb exoskeleton, comprising: The torso module includes an adjustable abdominal belt and two lower limb assemblies connected to the torso module via hip joints. Each lower limb assembly includes a thigh module, a knee joint, a calf module, and a lower support footrest connected in sequence for supporting on the floor to transmit the vertical load of the lower limb assembly. The hip joint and the knee joint are hinged joints. Each limb component also includes a knee actuation mechanism configured to change the angle of the knee joint when actuated; At least the thigh module and the lower leg module include at least one body attachment structure for attaching to a body part adjacent to the user; Its features are: The knee joint actuation mechanism includes a push rod having a central region slidably connected to the lower leg module for guided linear movement of the push rod along a linear displacement path; The push rod includes a lower end that, when not at the uppermost position of the linear displacement path, protrudes downwards below the lower support footrest. The push rod includes an upper end connected to the thigh module via a motion linkage mechanism configured to push the thigh module into an extended position when the push rod moves upward against the ground due to its lower end under the weight of the user's body, wherein the thigh module and the calf module are substantially parallel or aligned. A motion linkage mechanism connecting the upper end of the push rod to the thigh module includes a bending guide attached to the lower end of the thigh module adjacent to the knee joint. The bending guide extends from a first end to a second end, defining a trajectory from the first end toward the second end, wherein the continuous points of the bending guide gradually move away from the knee joint, and the upper end of the push rod is slidably connected to the bending guide.

2. The lower limb exoskeleton according to claim 1, wherein, The trunk module includes: Two underarm supports, each extending upwards from one hip joint; or Two underarm supports and two shoulder straps, wherein each underarm support extends upward from one hip joint; or Two underarm supports and one hip support, wherein each underarm support extends upward from a hip joint, and the hip support extends downward from the rear of the adjustable abdominal binder; or Two underarm supports, two shoulder straps, and a hip support, wherein each underarm support extends upward from a hip joint, and the hip support extends downward from the rear of the adjustable abdominal band.

3. The lower limb exoskeleton according to claim 1, wherein, The adjustable abdominal binder also includes vertical reinforcing ribs.

4. The lower limb exoskeleton according to claim 1, wherein, The torso module does not have a groin band for connecting the rear and front sides of the adjustable abdominal binder.

5. The lower limb exoskeleton according to claim 2, wherein, Each underarm support is connected to the hip joint located below via an incompressible connector or a flexible incompressible connector.

6. The lower limb exoskeleton according to claim 2 or 5, wherein, The length of each of the calf module, the thigh module, the push rod, and the connection between each underarm support and the corresponding hip joint can be adjusted by a length adjustment device or a telescopic length adjustment device included therein.

7. The lower limb exoskeleton according to claim 1, wherein, The continuous points of the bending guide from the first end to the second end form a decreasing acute angle relative to the straight line connecting each of the continuous points to the knee joint.

8. The lower limb exoskeleton according to claim 7, wherein, When the limb assembly is in its maximum flexed position, the upper end of the push rod is close to the first end of the flexion guide and defines an acute angle between 70° and 80°, and / or When the limb assembly is in its maximum extended position, the upper end of the push rod is close to the second end of the bending guide and defines an acute angle between 40° and 30°.

9. The lower limb exoskeleton according to claim 1, wherein, The knee joint actuation mechanism also includes a linear motor, one end of which is connected to the thigh module at a position adjacent to the second end of the bending guide, and the opposite end of which is connected to the calf module at a position adjacent to the knee joint.

10. The lower limb exoskeleton according to claim 9, wherein, The knee joint actuation mechanism integrates sensors configured to detect changes in tilt between the thigh and calf modules, or changes in the linear position of the push rod, or pressure on the second end of the push rod, wherein the linear motor is configured to be activated in response to the detection obtained by the sensors.

11. The lower limb exoskeleton according to claim 1, wherein, The limb assembly also includes a hand-assist system, which includes a drive rod or a drive rod with an adjustable length. The lower end of the hand-assist system is connected to the lower leg module via a connector, and the upper end of the hand-assist system has a handle that is slidably connected to the thigh module to guide the handle along the linear movement of the thigh module, further pushing the lower limb assembly toward the extended position.

12. The lower limb exoskeleton according to claim 1, wherein, The lower support footrest includes a foot module connected to the lower end of the calf module via an inserted hinged ankle joint.

13. The lower limb exoskeleton according to claim 12, wherein, The foot module is a type of footwear or a stirrup that can be attached to footwear.

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