JP2019528802A - Passive ankle prosthesis with energy reduction - Google Patents

Abstract

The ankle prosthesis includes a prosthetic leg. The lower ankle part is fixed to the artificial leg so that it can turn at the ankle joint part. The upper ankle is coupled to the lower ankle so as to allow vertical movement of the upper ankle relative to the lower ankle. The coupling spring is biased in the extended condition. The coupling spring is connected at the first end of the upper ankle. The second end of the coupling spring is movable under a first condition that engages with the lower ankle and a second condition that engages with the artificial leg. When the coupling spring is in the first condition, energy is accumulated by compression of the coupling spring, and when the coupling spring is in the second condition, energy is released from the coupling spring.

Description

Federally sponsored research or development statement

[0001] This invention was made with government support under H133G120256-13 awarded by the National Institutes of Health. The government has certain rights in this invention.

Cross-reference of related applications

[0002] This application claims priority to US Provisional Patent Application No. 62 / 322,524, filed April 14, 2016, the contents of which are hereby incorporated by reference in their entirety.

background

[0003] The field of the invention relates to ankle, foot and lower leg prosthesis devices. In particular, the field of the invention relates to passive ankle, foot and lower leg prosthesis devices.

[0004] Prosthetic ankles, foot devices have been described. (U.S. Patent Nos. 7,955,399; 7,862,622; 7,819,926; 7,648,533; 7,611,543; 7,578,852; 7,101,403; 6,942,704; 6,929,665; 6,436,149; 6,280,479; 6,206,934; 6,071,313; 5,913,901; 5,728,175; 5,593; 5 5,181,932; 5,156,630; 5,066,305; 4,764,172; 4,645,509; 4,605,417; 4,547,913; 4,442,554; 20110106274; 20090319055; 20090281638; 20090265018; 20080281436; 20080262635; 20080228288; 20080188950; 20080033579; 20070299544; 20070219641 20050049721; 20050038525; 20050033451; 20050033450; 20040236435; 20040225375; 20040186590; 20030105531, the contents of which are incorporated herein by reference in their entirety).

[0005] An estimated 623,000 people live in the United States with severe lower leg amputations (defined as lower leg amputations larger than toe amputations). Of these amputations, 78% are due to peripheral vascular disease (PVD) and 45% are due to PVD in individuals with type I or type II diabetes. People with an increasing incidence of diabetes and PVD and lower socio-economic status are more susceptible to type II diabetes, and the demand for affordable, high-quality leg prostheses has not been high. Prostheses currently available on the market include passive and active devices, but none of them fully satisfy the user's requirements.

[0006] Passive prosthesis ankles / legs currently commercially available are based on leaf springs that absorb and release energy during walking. These springs reduce the impact of ground reaction forces that occur during walking and convert some of the absorbed energy into energy that is used to advance the body forward. However, the stored energy is significantly less than that normally required to advance the body forward during pushoff in an intact walk. Cutting patients using these existing passive devices tend to walk slowly and consume more energy than normal pedestrians. In order to obtain the desired mechanical characteristics, the ankle joint must display an active prosthesis. More energy must be drawn from the ankle than that given to the ankle deflection.

[0007] Passive prosthetic ankles are a more commonly prescribed practice and are economically priced, but lacking actuators lacks the push-off that is the driving force observed in the original ankle. ing. As a result, passive prostheses end multiple quality of life declines, including asymmetric walking (for unilateral amputees), slow self-selective walking speed, high metabolic cost per distance traveled, and increased pain in the remaining limbs. Cause to user.

[0008] Active ankles, previously developed in university laboratories, are now commercialized. BiOM (TM) by BionX, Odyssey (TM) and Jackspring (TM) by SpringActive are currently in a relatively early commercialization stage. These previous research prosthetic ankle designs address the much energy required during push-off to advance the body forward. The limitations of these active (biotechnological) designs are the increase in ankle size, weight and cost. The extent to which the size and weight increase is roughly determined by the amount of power provided by the actuator to advance the body forward. In order to minimize the increased size and weight, a good prosthesis design is one in which most desired behavior is obtained by passive elements and requires a motor for limited contribution.

[0009] A review of different types of ankle prostheses can be found in the website for the Online Learning Center for the American Prosthetics and Orthotics Academy, Chapter 3: Human Foot and Ankle and Prosthetic Foot / Ankle Mechanism Functions, including the contents of this application Are incorporated in full for reference. (US Published Application 2007/0061016; “SPARKy 3: Design of an activerobotic ankle prosthesis with two actuated degrees of freedom using regenerative kinetics”, Bellman, RD, Holgate, MA, Sugar, TG, Proceedings of the 2nd Biennial IEEE / RASEMBS International Conference on Biomedical Robotics and Biomechatronics, 2008; and “Powered Ankle-Foot Prosthesis”, Au, SK, Herr, HM, IEEE Robotics and Automation Magazine. Vol. 15 (3) (pp 52-59), 2008; The entirety is incorporated into this application for reference.)

[0010] Thus, a new design for a passive prosthesis ankle / foot, particularly a new design that exhibits increased energy reduction with increasing walking speed, is desirable. Also particularly desirable are new designs for passive prosthetic ankles / foot, which do not require sensors or actuators to achieve active behavior associated with normal walking.

Overview

[0011] Disclosed is a lower limb prosthesis device comprising at least two degrees of freedom mechanisms. Exemplary devices include conventional spring and elastic beam net work. In the disclosed device, energy stored along one degree of freedom (eg, energy generated by the weight of the amputee) is released along different degrees of freedom and resembles the original ankle mechanical features. Achieved mechanical characteristics. In this way, the ankle can exhibit an “active behavior”, in which more energy is released at the ankle joint than the energy that is stored solely by ankle deflection. The energy stored by the leg deflection is added to the energy stored by the ankle deflection. This total energy is then released at the ankle during push-off.

[0012] In addition to the related device described in Patent No. 8,721,737, active behavior using only passive components has not previously been achieved in prosthetic ankle designs. Traditional passive designs do not match the original ankle mechanical features, and traditional active designs require large and heavy actuators to achieve similar mechanical features. The devices disclosed herein typically do not require sensors and actuators to achieve active behavior associated with normal walking.

[0013] The device disclosed herein is based on the inventor's initial operation as disclosed in US Pat. No. 8,721,737, which is incorporated herein by reference in its entirety and into the leg. Describes how the energy stored by the deflection along can be used for push-off at the ankle.

[0014] Devices such as those described herein allow deflection and energy storage along the legs to occur in a heel strike (when a foot hits the ground). Energy is stored in the spring and then released after the ankle has achieved maximum dorsiflexion for timely push-off. An additional improvement discovered in the design embodiments disclosed herein is that the amount of energy applied during push-off is related to pedestrian speed. The relationship between walking speed and energy generated at the ankle has recently been documented in the analysis of normal healthy pedestrians. Embodiments such as those disclosed herein provide some important aspects of the original ankle joint (eg, non-linear rotational stability and rotational motion output that increases with walking speed (eg, push-off as a driving force)). ) To provide a passive ankle device.

[0015] An exemplary embodiment of an ankle prosthesis includes a prosthesis. The lower ankle is fixed to the prosthesis so that it can turn at the ankle joint. The upper ankle is connected to the lower ankle and allows the upper ankle to move vertically relative to the lower ankle. The coupling spring is biased in the extended condition. The coupling spring is connected to the upper ankle at the first end. The second end of the coupling spring is movable between a first condition engaged with the lower ankle and a second condition engaged with the artificial leg. Energy is stored by the compression of the coupling spring when the coupling spring is in the first condition. Energy is released from the coupling spring when the coupling spring is in the second condition.

[0016] In a further exemplary embodiment, the upper ankle portion includes a ball spline that is telescopically movable within the lower ankle portion. The ankle prosthesis also illustratively includes at least one sprag secured for movement to the lower ankle. At least one sprag is engageable with the ball spline. The operable engagement of at least one sprag with the ball spline allows movement of the upper ankle toward the lower ankle. The operable engagement of at least one sprag with the ball spline further prevents movement of the upper ankle away from the lower ankle. In an exemplary embodiment, the ankle prosthesis further includes a sprag release spring secured at the first end to the lower ankle. The second end of the sprag release spring selectively engages with the upper ankle, and when the second end of the sprag release spring engages with the upper ankle, the translation of the upper ankle toward the lower ankle is The energy is stored by the compression of the sprag release spring. In an exemplary embodiment, at least one sprag wire is secured between the second end of the sprag release spring and the at least one sprag. Disengagement between the second end of the sprag release spring and the upper ankle portion transmits a rotational force to the at least one sprag via the at least one sprag wire, and at least one from the ball spline of the upper ankle portion. Disengage the two sprags.

[0017] In a further embodiment, the lower ankle portion includes a shelf. The block portion is placed at the second end of the coupling spring. The block portion engages with the shelf portion of the lower ankle portion when the coupling spring is in the first condition. The jamming mechanism is connected to the block portion. The jamming mechanism engages with the prosthetic foot, and shifts the block portion from the engagement with the shelf portion of the lower ankle portion of the first condition of the coupling spring to the engagement with the artificial leg of the second condition of the coupling spring.

[0018] In a further exemplary embodiment, the ankle prosthesis includes a dorsiflexed contact piece secured to the lower ankle. The dorsiflexion bend is fixed to the prosthesis. The dorsiflexion contact piece is configured to selectively engage the displacement end of the dorsiflexion flexion and reduce the angle between the prosthetic leg and the lower ankle, from rotation around the ankle joint, from the dorsiflexion flexion To store energy.

[0019] In a further exemplary embodiment, the ankle prosthesis includes a plantar flexure contact piece secured to the lower ankle. The bottom flexion bent portion is fixed to the artificial leg. The plantar flexure contact piece is configured to selectively engage the displacement end of the plantar flexion flexion, and the angle between the prosthetic leg and the lower ankle increases, and the plantar flexion from the rotation around the ankle joint To store energy.

[0020] In a further exemplary embodiment, the ankle prosthesis is a passive ankle prosthesis, where the energy that is reduced increases with the walking speed of the patient. In the exemplary embodiment, energy is passively reduced using an ankle prosthesis. In an exemplary embodiment of the passive energy reduction method, the coupling spring is operated at a first condition using a second end of the coupling spring engaged with the lower ankle. The translational force is received at the upper ankle. Energy is stored by the compression of the coupling spring. The coupling spring is operated under a second condition using the second end of the coupling spring engaged with the prosthesis. The energy stored in the coupling spring is released to assist the rotation of the prosthetic leg around the ankle joint with respect to the upper ankle.

FIG. 1 is a schematic diagram of an exemplary embodiment of a passive ankle prosthesis. FIG. 2 is a flowchart of an exemplary embodiment of the operation of a passive ankle prosthesis. FIG. 3A depicts an exemplary functional state of a passive ankle prosthesis in action. FIG. 3B depicts an exemplary functional state of a passive ankle prosthesis during operation. FIG. 3C depicts an exemplary functional state of a passive ankle prosthesis during operation. FIG. 3D depicts an exemplary functional state of a passive ankle prosthesis during operation. FIG. 3E depicts an exemplary functional state of a passive ankle prosthesis during operation. FIG. 3F depicts an exemplary functional state of a passive ankle prosthesis during operation. FIG. 4 is a perspective view of an exemplary embodiment of a passive ankle prosthesis. FIG. 5 is a graph presenting exemplary experimental data of ankle moment (Nm) and ankle angle for a modeled passive ankle and subject.

Detailed disclosure

[0026] Unless otherwise specified or indicated by context, the terms "a", "an") and "the" mean "one or more". For example, “a mechanism” should be interpreted to mean “one or more mechanisms”.

[0027] As used herein, the terms "include", "including") have the same meaning as the terms "comprise", "comprising". The term “comprise” (“comprising”) is an open transitional term that allows additional components to be included in the claimed components. It is interpreted as it is. The terms “consist” and “consisting of” refer to a “closed” word that does not allow additional components to be included in the claimed components. ”Transitional terms). The term “consisting essentially of” is interpreted to be partially closed allowing the inclusion of only additional components that do not fundamentally change the claimed subject matter. Is done.

FIG. 1 is a schematic diagram of an exemplary embodiment of a passive ankle prosthesis 10. FIG. 4 also provides a perspective view of an exemplary embodiment of a passive ankle prosthesis. The passive ankle prosthesis 10 includes a prosthetic leg 12. The prosthetic leg 12 includes an elastic material, particularly an elastic material that is placed on the bottom of the prosthetic leg 12. As depicted in FIG. 4, an exemplary embodiment of a passive ankle prosthesis 10 may include one or more toe prostheses 14 coupled to a prosthetic leg 12 for pivotal movement, although other forms of It will be appreciated that a toe prosthesis is used, or that other embodiments have a toe prosthesis that is fixed and an integral part of the prosthesis 12.

The passive ankle prosthesis 10 further includes an upper ankle portion 16 and a lower ankle portion 18. The lower ankle portion 18 is connected to the artificial leg 12 so as to be able to turn at the ankle joint portion 20. The ankle joint portion 20 illustratively includes a pivot pin 22 around which the lower ankle portion 18 and the prosthetic leg 12 can rotate.

The upper ankle portion 16 can be translated with respect to the lower ankle portion 18. Ball spline shaft 24 extends from upper ankle portion 16 and is received within a spline chamber 26 defined within lower ankle portion 18. The pair of sprags 28 is fixed inside the spline chamber 26 so as to be able to turn with the lower ankle portion 18, and forms a jamming mechanism 30 together with the tongue portion 32 of the ball spline shaft 24. The sprag acts as a mechanical diode and allows the upper ankle portion 16 to move in the arrow direction 34 relative to the lower ankle portion 18 when loaded, as will be described in more detail herein. The sprags 28 resist or prevent the upper ankle 16 from moving in the opposite direction until the passive ankle prosthesis 10 is unloaded and mechanically reset. The upper ankle portion 16 further includes a sprag release mechanism 36. The sprag release mechanism 36 includes a cone adapter 38 that facilitates mechanical connection between the lower leg of the amputee and the passive ankle prosthesis. A mechanical link 40 of the sprag release mechanism 36 connects the cone adapter 38 to the upper ankle 16. The sprag release spring 42 is fixed to the lower ankle portion 18 by connection... 44 and is urged at the extended position. The sprag release spring 42 ends at the end of the spring adapter 46 that is opposite the connection point 44. The spring adapter 46 is selectively engaged by the link 40 of the sprag release mechanism 36, as will be described in further detail herein.

[0031] The coupling spring 48 is fixed between the coupling arm 50 of the upper ankle 16 and is coupled to the coupling arm 50 so as to be movable at a coupling point 52. The coupling spring 48 is illustratively biased in an extended configuration. A lower end portion of the coupling spring 48 is fixed to the movable block portion 54, and the movable block portion 54 is held so as to be movable inside the channel in the artificial leg 12. The block portion 54 includes a jamming mechanism 60 that acts as described herein to lock the lower end of the coupling spring 48 at a position relative to the prosthetic leg 12. The block 54 is held by the shelf 62 of the lower ankle 18 so that it can move.

[0032] The lower ankle portion 18 illustratively includes an upper location 64 that defines the spline chamber 26. The lower ankle portion 18 further includes an ankle position 66 through which the pivot pin 22 extends to define the ankle joint portion 20. The lower ankle portion 18 further includes a lower portion 68 with a shelf 62. The dorsiflexion contact piece 70 is placed on the lower portion 68. The dorsiflexion contact piece 70 engages with the end portion of the dorsiflexion bending portion 72 of the artificial leg 12. In the exemplary embodiment, the dorsiflexion bend is bifurcated as exemplarily depicted in the inset of FIG. The dorsiflexion bend 72 may include two protrusions 74 by way of example. The protrusion 74 may taper in width as depicted as the dorsiflexion bend 72 extends from a fixed end 76 secured to the prosthesis 12 to a displacement end 78. It will be appreciated in embodiments that two or more dorsiflexed contact pieces 70 such that the lower portion 68 of the lower ankle portion 18 illustratively engages each of the protrusions 74 of the dorsiflexion bend 72. It may be provided.

[0033] The lower ankle 18 further includes a plantar contact piece 80. The bottom bent contact piece is configured to selectively engage with a bottom bent portion 82 extending from the fixed end portion 84 to the displacement end portion 86. The fixed end portion 84 is fixed to the artificial leg 12. The bottom bent contact piece 80 may be configured to selectively engage with the bottom bent portion 82 at the displacement end 86 of the bottom bent portion. In order to include the dorsiflexion contact piece 70 in the embodiment, the lower ankle portion 18 may include one sole flexion contact piece 80 or two or more sole flexion contact pieces 80. A plurality of plantar flexure contact pieces may be used illustratively to distribute engagement between the lower ankle portion 18 and the plantar flexion bend 82. In the exemplary embodiment, the lower ankle 18 may comprise two or more plantar contact pieces 80, illustratively one on one side of the lower ankle 18. Such bottom flexion contact pieces 80 may correspond to the same number of oriented, bottom flexion bent portions 82 of the prosthetic leg 12.

[0034] FIG. 2 is a flowchart depicting an exemplary embodiment of a motion conversion method 100 in a passive ankle prosthesis. Implementation of this method 100 is exemplary as described in more detail herein and may be performed illustratively using an embodiment of a passive ankle prosthesis 10 as described above. This method embodiment operates to use two obligately coupled degrees of freedom to achieve the driving push-off in a manner where energy reduction increases during walking speed increases.

[0035] At step 102, an input of translational work is received. As described in more detail herein, a passive ankle prosthesis uses a translational motion as created by a force (F) along the leg that provides deflection (r) along the leg. The input of the translation operation is exemplarily given by the equation (1).

∫ F (r) ・ dr (1)

[0036] Next, in step 104, the method continues when the passive ankle prosthesis accumulates the input translational motion into the conversion spring (spring constant (k), flexure (x), x is a function of r). To do. This is illustratively expressed by equation (2).

∫kx ^{2/2 (2)}

[0037] To achieve power push-off in a passive ankle prosthesis design, the stored energy is converted into rotational motion around the ankle joint and output as rotational motion at step 106. This is exemplarily shown by the equation (3).

∫M (θ) ・ dθ (3)

[0038] Here, the output rotational motion is the integral of the moment (M) around the ankle joint via the angle θ. In the exemplary operation of this method embodiment and passive ankle prosthesis 10 embodiment, the converted energy is stored at maximum leg force early in the stance phase. A passive ankle prosthesis converts its translational energy into rotational motion at the maximum dorsiflexion of the prosthesis. Initial posture accumulation and increased motion output are achieved, for example, due to the maximum value F occurring early in the stance phase. Since the maximum value of F increases with walking speed, in the embodiments disclosed herein, the stored translational energy and rotational motion output increase with increasing walking speed.

[0039] FIGS. 3A-3F depict the action of a passive ankle prosthesis and similarly depict an exemplary embodiment for performing the method 100 of FIG. It will be appreciated that the structures and functions described above apply equally to FIGS. 3A-3F, particularly with respect to FIG. 1, for the sake of simplicity, each figure represents a passive ankle prosthesis 10 described above. It does not include all of the reference signs that identify the features.

[0040] Referring to FIG. 1, the functional components of an exemplary embodiment of a passive ankle prosthesis 10 in a neutral or unloaded position are depicted. 3A-3F depict the function of the passive ankle prosthesis 10 through the physiological state of the walking cycle. FIG. 3A depicts a passive ankle prosthesis 10 in heel contact. In the heel contact, the prosthetic leg 12 contacts the ground G, particularly at the heel H of the prosthetic leg 12. Contact of the prosthetic foot 12 with the ground G is transmitted to the patient's translational upper ankle 16 and compresses the coupling spring 48 and sprag release spring 42 in the direction of arrow 88. The upper ankle portion 16 also moves in the arrow direction 88 with respect to the lower ankle portion 18. When the prosthetic leg 12 continues to move so as to be in complete contact with the ground G, the bottom bent contact piece 80 engages with the bottom bent portion 82 and moves the displacement end portion 86 of the bottom bent portion 82. As described above, the translational force in the arrow direction 88 is accumulated in the sprag release spring 42, the coupling spring 48, and the bottom bent portion 82 during the heel contact.

In FIG. 3B, the prosthetic leg 12 is flat with respect to the ground G. The artificial leg 12 is slightly loaded because the center of mass of the patient is placed in the direction behind the ankle joint 20. As the patient continues to move forward, the upper ankle portion 16 and the lower ankle portion 18 continue to pivot about the ankle joint 20 in the arrow direction 89 along the patient's leg (not shown). As the patient's center of mass continues to be aligned vertically with the ankle joint 20, additional translational force is applied to the passive ankle prosthesis 10 in the arrow direction 88, which causes the upper ankle 16 to move in the lower ankle 18 in the arrow direction 88. Compress further. This, in turn, further compresses the sprag release spring 42 and the coupling spring 48, storing energy therein. The rotation of the prosthetic foot 12 that is in complete contact with the ground G further displaces the displacement end portion 86 of the bottom flexion bending portion 82 and accumulates energy therein.

[0042] In FIG. 3C, the passive ankle prosthesis 10 is fully loaded at the center of mass of the patient vertically above the ankle joint 20. This loads the passive ankle prosthesis 10 with the total weight of the patient. In the flat condition of the fully loaded leg, the coupling spring 48 is in a fully compressed state and accumulates the maximum available translational force. Under the condition that the full load is applied, the coupling spring 48 appears to reduce the compression through expansion of the coupling spring 48, and between the block portion 56 at the lower end portion of the coupling spring 48 and the shelf portion 62 of the lower ankle portion 18. The engagement exemplarily places a force on the lower ankle 18 in the arrow direction 88. The coupling spring 48 exemplarily applies a force to the upper ankle 16 in the direction 90 of the arrow. The sprag release spring 42 also transmits a similar extensible force to the lower ankle portion 18 and the upper ankle portion 16. However, when the upper ankle portion 16 translates with respect to the lower ankle portion 18 in the direction of the arrow 88, the ball spline 24, more specifically, the tongue 32 of the ball spline 24 engages the sprag 28 and rotates the sprag 28. In the maximum compression state, the coupling spring 48 is locked, but the sprag 28 locks the relative position between the upper ankle portion 16 and the lower ankle portion 18 by friction. The dorsiflexion contact piece 70 begins to engage with the displacement end 78 of the dorsiflexion bend 72. This accumulates rotational energy in the dorsiflexion bend 72.

[0043] FIG. 3D depicts the passive ankle prosthesis 10 in a condition immediately after maximum dorsiflexion. The patient's leg, upper ankle portion 16, and lower ankle portion 18 then pivots around the ankle joint 20 in the arrow direction 89 on the opposite side of the previous rotational direction.

[0044] The rotation of the upper ankle portion 16 and the lower ankle portion 18 in the arrow direction 89 of the ankle joint portion 20 moves the lower portion 68 of the lower ankle portion 18 in a direction away from the ground G.

[0045] Further, the movement of the lower portion 68 away from the ground G similarly moves the shelf 62 in the same direction. The block portion 58 supported by the ledge 62 also moves in this direction until the jamming mechanism 60 including the sprag 92 engages the lower surface 94 of the channel 58. The block portion 56 is released from the engagement with the shelf portion 62 by the sprag 92 of the jamming mechanism 60 (for example, the lower surface 94 of the channel 58) that engages with the artificial leg 12. The block 56 settles to an equilibrium point within the channel 58 under the tensile force of the coupling spring 48, but still maintains the energy stored in the compression of the coupling spring 48, which in turn is An extensible force is applied between the artificial leg 12 and the upper ankle part 16. This mechanical coupling between the upper ankle portion 16 and the prosthetic leg 12 transfers the energy stored in the leg deflection to the releasable energy as ankle rotation during the push-off phase.

[0046] FIG. 3E depicts the passive ankle prosthesis 10 toward the end of the driving push-off. During the push-off that is the driving force, the coupling spring 48 and the dorsiflexion bend 72 release the energy stored within these springs, causing the foot to generate torque around the ankle joint 20 in the arrow direction 91. . This moves the pedestrian forward. When push-off as a driving force continues, the rotation of the lower ankle portion 18 around the ankle joint portion 20 causes the bottom flexion bent portion 82 to engage the bottom flexion contact piece 80, and a part of the bottom flexion bent portion 82 is brought into the bottom flexion bent portion 82. Accumulate rotational energy. Since the jamming mechanism 30 locks the ball spline 24 with the sprags 28, as depicted in FIG. 3E, just before the toe-off, the coupling spring 48 may not release all of the energy stored therein. Although this may prevent the upper ankle 16 from being released and moved upward, as well as preventing further upward movement of the upper ankle 16. Thus, some energy may remain stored in the coupling spring 48. In the exemplary embodiment, although not depicted in FIG. 3E, energy may likewise remain stored inside the dorsiflexion 72.

[0047] FIG. 3F depicts a passive ankle prosthesis during toe off and reset of the swing phase. Once the foot breaks contact with the ground (toe off), the force applied by the leg to move the foot forward causes the cone adapter 38 to move upward relative to the upper ankle 16 and at least Partially separate from the upper ankle 16. This operates the sprag release mechanism 36 by moving the link 40 to disengage the sprag release spring 42 from the spring adapter 46. The energy stored in the sprag release spring 42 moves the spring adapter 46 upward in the arrow direction 90. When the spring adapter 46 moves upward in the arrow direction 90, the sprag wire 54 connected between the spring adapter 46 and the sprag 28 applies a releasing force to the sprag 28. The sprag 28 rotates and disengages the sprag 28 from the tongue 32 of the ball spline shaft 34. With the sprag 28 no longer locking the ball spline 24, the upper ankle 16 is released for movement in the arrow direction 90. The remaining energy stored in the coupling spring 48 is released to move the upper ankle 16 in the direction 90 of the arrow relative to the tongue ankle 18.

[0048] The energy stored in the plantar flexion 82 is released through the fixed end 84 and rotates the prosthesis 12 around the ankle joint 20 that lifts the foot 12 and the toe. The released energy in the coupling spring 48 releases the block 56 for internal movement of the channel 58, and rotation of the prosthesis 12 around the ankle joint 20 in the arrow direction 91 causes the block 56 to move inside the channel. Move in the arrow direction 93. This movement of the prosthetic leg 12 and the block portion 56 causes the block portion 56 to rest on the shelf 62 of the tongue ankle portion 18. In this way, the passive ankle prosthesis is reset to the unloaded position as depicted in FIG. 1 and is ready for later steps by the patient.

[0049] FIG. 5 is a graph depicting an exemplary embodiment of a passive ankle prosthesis 108 and exemplary data for M (θ) of a human subject 110. As can be seen from the graph of FIG. 5, the motion output of the passive ankle prosthesis closely models that of the original ankle.

[0050] As described herein, in a passive ankle prosthesis and method of operation, the passively obtained energy reduction increases with increasing walking speed. Since the increased walking speed creates a large force, this increased force is captured, accumulated, and released by the embodiments disclosed herein, creating a passive ankle prosthesis, but here Since the motion output increases as the speed increases, walking is passively supported using reduction of ankle motion over a wide range of walking speeds.

[0051] It will be readily apparent to those skilled in the art that various substitutions and modifications can be made to the invention disclosed herein without departing from the scope and spirit of the invention. The invention properly described herein by way of example may be practiced without any elements, elements, limitations, or limitations not specifically disclosed herein. The terms and expressions that have been used are used as descriptive terms and not as limiting terms, so in the use of such terms and expressions the exclusion of any equivalents of the features shown and described, It is not intended to exclude that part, and various modifications are possible within the scope of the present invention. As such, the invention has been illustrated by specific embodiments and optional features, but variations and / or variations on the concepts disclosed herein may be relied upon by those skilled in the art. It should be understood that modifications and variations are considered to be within the scope of the present invention.

[0052] A number of patent and non-patent literature are listed herein. The listed documents are incorporated by reference in their entirety. If there is a conflict between the definition of a term in the specification and the definition of the term in the listed documents, the term should be interpreted based on the definition of the specification.

[0053] In the description above, certain terms have been used for brevity, clarity and understanding. Unnecessary limitations should not be inferred beyond the requirements of the prior art. This is because such terms are used for illustrative purposes and are intended to be interpreted broadly. The different system and method steps described herein may be used alone or in combination with other systems and methods. It is expected that various equivalents, alternatives, and modifications are possible within the scope of the appended claims.

[0054] The functional block diagrams, operational sequences, and flowcharts provided in the figures are representative exemplary configurations, ambient situations, and methodologies for carrying out the novel aspects of the disclosure. For simplicity of explanation, the methodology included in this document may be in the form of a functional block diagram, operational sequence, flowchart, and may be described as a series of operations, but this methodology is not limited by the order of operations. Rather, it should be understood and appreciated that some operations may occur in a different order and / or concurrently with other operations shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be displayed as a series of interrelated states or phenomena (eg, a state diagram). Moreover, not all operations illustrated in the methodology are required for a new implementation.

[0055] This description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other embodiments may have structural elements that are not different from the literal wording of the claims, or they may be equivalent structural, with subtle differences from the literal wording of the claims. Including elements is included within the scope of the claims.

Claims (20)

In an ankle prosthesis,
With a prosthetic leg,
A lower ankle fixed to the prosthetic leg so that it can turn at the ankle joint;
An upper ankle portion coupled to the lower ankle portion to allow vertical movement relative to the lower ankle portion;
A coupling spring biased under the extended condition, wherein the coupling spring is connected to the upper ankle at the first end;
The second end of the coupling spring is movable under a first condition engaged with a lower ankle portion and a second condition engaged with a prosthetic leg, and the coupling spring is in the first condition when the coupling spring is in the first condition. The coupling spring, wherein energy is stored by compression of the spring, and energy is released from the coupling spring when the coupling spring is in the second condition;
An ankle prosthesis. The upper ankle portion includes a ball spline that is movable in a retractable manner inside the lower ankle portion, and the ankle prosthesis is:
It further comprises at least one sprag fixed to be movable to the lower ankle portion and engageable with the shaft of the ball spline, wherein the operative engagement of the ball spline and the at least one sprag is the upper ankle. The ankle prosthesis according to claim 1, wherein a portion is allowed to move toward the lower ankle and prevents the upper ankle from moving away from the lower ankle. The ankle prosthesis of claim 2, further comprising a sprag return spring and at least one sprag wire,
The sprag return spring has a first end fixed to the lower ankle portion, a second end portion of the sprag return spring is selectively engaged with the upper ankle portion, and the second end of the sprag return spring is The portion is engaged with the upper ankle portion, and the parallel movement of the upper ankle portion toward the lower ankle portion accumulates energy by compression of the sprag return spring,
The at least one sprag wire is fixed between the second end portion of the sprag return spring and the at least one sprag, and is engaged between the second end portion of the sprag return spring and the upper ankle portion. The ankle prosthesis is released by transmitting a rotational force to the at least one sprag via the at least one sprag wire to disengage the at least one sprag from the ball spline of the upper ankle portion. A cone adapter movably connected to the lower ankle,
A sprag release mechanism comprising a plurality of links, wherein at least one of the plurality of links selectively provides engagement between the sprag release mechanism and the upper ankle portion;
With
The ankle prosthesis according to any one of claims 1 to 3, wherein movement of the cone adapter away from the upper ankle releases the engagement from the at least one link and the sprag release spring. The lower ankle portion includes a shelf, and the ankle prosthesis is
A block portion at the second end of the coupling spring, wherein the block portion engages with the shelf of the lower ankle when the coupling spring is in the first condition;
A jamming mechanism connected to the block portion, wherein the block portion in the first condition of the coupling spring is engaged with the shelf portion of the lower ankle portion, and the second condition of the coupling spring is in the second condition. The jamming mechanism that engages with the prosthetic leg to shift to engagement with the prosthetic leg;
The ankle prosthesis according to any one of claims 1 to 4, further comprising:   During the swing phase, the movement of the upper ankle that lifts the second end of the coupling spring and the rotation of the prosthetic leg around the ankle joint causes the lower ankle to re-set the ankle prosthesis. The ankle prosthesis according to claim 5, wherein the block part is engaged with the shelf part. A dorsiflexion contact piece fixed to the lower ankle,
A dorsiflexion bend fixed to the prosthetic leg, wherein the dorsiflexion contact piece is configured to selectively engage a displacement end of the dorsiflexion bend, between the prosthetic leg and the lower ankle. From the rotation to reduce the angle around the ankle joint part, energy is accumulated in the dorsiflexion flexion part, and the dorsiflexion flexion part,
The ankle prosthesis according to claim 1, further comprising:   The dorsiflexion contact portion is fixed to a lower portion of the lower ankle portion, and the dorsiflexion bend portion is fixed to the artificial leg at a fixing end of the dorsiflexion bend portion, and the dorsiflexion bend portion under no load condition The ankle prosthesis according to claim 7, wherein the ankle prosthesis extends substantially parallel to the artificial leg.   The dorsiflexion bent portion is bifurcated into a first projection portion and a second projection portion, the dorsiflexion contact piece is a first dorsiflexion contact piece, and the lower ankle portion is a second dorsiflexion. The ankle prosthesis according to claim 7 or 8, further comprising a contact piece, wherein the first dorsiflex contact piece and the second dorsiflexion contact piece selectively engage with the first protrusion and the second protrusion. .   The said dorsiflexion part releases the energy stored therein, and increases the angle around the ankle joint between the prosthetic leg and the lower ankle part. Ankle prosthesis.   The load input phase (translative input force) is accumulated in the coupling spring, and the force input by rotation is accumulated in the dorsiflexion bend. An ankle prosthesis according to one item.   12. An ankle prosthesis according to claim 11, wherein in the push-off phase, the energy stored in the binding spring and the dorsiflexion bend is released to advance the patient using the ankle prosthesis forward. The ankle prosthesis is
A plantar contact piece fixed to the lower ankle,
A bottom flexion bent portion fixed to the prosthetic leg, wherein the bottom flexion contact piece is configured to selectively engage with a displacement end portion of the bottom flexion flexion portion; Accumulating energy in the plantar flexion from a rotation that increases the angle around the ankle joint in between,
The ankle prosthesis according to claim 1, further comprising:   The ankle prosthesis according to claim 13, wherein the bent-bend portion releases energy stored therein and reduces an angle between the prosthetic leg and the lower ankle part.   In the load phase, the bent flexion part releases the energy stored therein, and in the toe-off phase, the upper ankle part and the lower ankle part move to a vertical alignment in the ankle joint part. 15. An ankle prosthesis according to claim 14, wherein during the swing leg phase, the bent flexion releases the energy stored therein and lifts the prosthetic leg.   16. An ankle prosthesis according to any one of the preceding claims, further comprising at least one toe prosthesis fixed for movement to the prosthetic leg.   17. A passive ankle prosthesis according to any one of the preceding claims having energy reduction with increasing walking speed.   A method for reducing passive energy in an ankle prosthesis according to any one of the preceding claims. Using the second end of the coupling spring engaged with the lower ankle portion, operating the coupling spring in the first condition;
Receiving a translational force at the upper ankle,
Storing energy by compression of the coupling spring;
Using the second end of the coupling spring engaged with the prosthetic leg, operating the coupling spring in the second condition;
Releasing energy stored in the coupling spring to assist rotation of the prosthetic leg with respect to the upper ankle;
The method of claim 18, further comprising:   20. A method according to claim 18 or 19, wherein the energy reduction increases with walking speed.

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