Robotic foot unit biomechanically mimicking the ankle

Abstract

The invention relates to an ankle prosthesis (10) comprising at least one tibia part (20) comprising at least one first spring (222) and at least one motorized spring (22) with at least one first motor (221) enabling compression of said first spring (222) and comprising at least one foot part (30) with at least one front base (311) and at least one rear base (321) providing contact with the ground, at least one inversion / eversion mechanism (50) to ensure the eversion and inversion movements of the ankle; comprising at least one dorsiflexion element (60) with at least one dorsiflexion spring (61) extending from the front base (311) to the rear base (321) to provide dorsiflexion and plantar flexion movements of the ankle. It is characterized in that one end of said motorized spring (22) is connected to at least one sliding guide slot (71) to enable it to be moved in at least one sliding trajectory (a), that it comprises at least a second motor (40) controlling the sliding movement of the motorized spring (22) within the said sliding guide slot (71), as well as controlling the compression of the said dorsiflexion spring (61).

Description

[0001] ROBOTIC FOOT UNIT BIOMECHANICALLY MIMICKING THE ANKLE

[0002] TECHNICAL FIELD

[0003] The invention relates to an ankle prosthesis comprising at least one tibia part comprising at least one first spring and at least one motorized spring with at least one first motor enabling compression of said first spring and comprising at least one foot part with at least one front base and at least one rear base providing contact with the ground, at least one inversion / eversion mechanism to ensure the eversion and inversion movements of the ankle; comprising at least one dorsiflexion element with at least one dorsiflexion spring extending from the front base to the rear base to provide dorsiflexion and plantar flexion movements of the ankle.

[0004] BACKGROUND

[0005] With the developing technology, various prostheses are developed to mimic the function of the missing limbs of people who have lost limbs due to congenital or later diseases or accidents, etc. The main objectives in the development of prostheses are to produce light-weight, cost- effective, and accessible products that can fully realize the function of the lost limb.

[0006] Ankle prostheses are mainly developed for people with limb loss below the knee. Ankle prostheses provide an imitation of the mimics of the foot and ankle during the movements of a person's foot such as walking and sit to stand. If the walking movement is considered as a cycle, it can be said that it basically consists of grounding, push-off, and swing motions. In this cycle, it is seen that there are flexion and extension movements, especially during the intervals of pressing down and pushing off the ground. In order to provide these movements, elastic elements are included in ankle prostheses. While the elastic elements provide the absorption of the heel-strike during the grounding phase, they store energy on themselves during the stance phase and give this energy to the ground and provide thrust for the ankle.

[0007] The human ankle has degrees-of-freedom in three cardinal planes (sagittal, transverse, and frontal plane) depending on the terrain condition of the ground during stepping or in standing position. Accordingly, the foot part performs internal and external rotation of the foot; inversion and eversion movements; dorsiflexion and plantar flexion movements in the said planes. In the present art, ankle prostheses that provide such degrees-of-freedom have complex mechanical motion mechanisms. As a result, prostheses have high weight and large volumes.

[0008] The application numbered 2020 / 22500 in the literature, relates to an ankle prosthesis. According to the present application, the object of the invention is to provide an ankle prosthesis or orthosis that increases the energy efficiency needed for an ankle prosthesis or orthosis to move, again by storing, keeping, and then releasing the energy during the movement of the device.

[0009] As a result, all the above-mentioned problems have made innovation in the relevant technical field imperative.

[0010] BRIEF DESCRIPTION OF THE INVENTION

[0011] The present invention relates to an ankle for eliminating the above-mentioned disadvantages and bringing new advantages to the relevant technical field.

[0012] An object of the invention is to provide an ankle prosthesis that can mimic the movements of a human ankle with a light and compact structure.

[0013] The present invention is an ankle prosthesis comprising at least one motorized spring contained in the tibia part having at least one first spring and at least one first motor providing compression of said spring and at least one foot part having at least one front base and at least one rear base providing contact with the ground, at least one inversion / eversion mechanism for providing the eversion and inversion movements of the ankle, at least one dorsiflexion element having at least one dorsiflexion spring extending from the front base to the rear base in order to simulate the dorsiflexion and plantar flexion movements of the ankle, in order to realize all the objects that will emerge from the abovementioned and the following detailed description. Accordingly, its novelty is that one end of said motorized spring is connected to at least one sliding guide slot to enable it to be moved in at least one sliding trajectory, that it comprises at least a second motor controlling the sliding movement of the motorized spring within the said sliding guide slot, as well as controlling the compression of the said dorsiflexion spring. Thus, while controlling the dorsiflexion movement with a single motor, the sliding mechanism is controlled to obtain the forward thrust during push-off. In this way, both a high controllability and a compact prosthesis structure are obtained. A possible embodiment of the invention is characterized in that it comprises at least one inversion / eversion mechanism operating independently from each other for the front base and the rear base in the front part of the foot part and in the heel part, respectively. Thus, the front and back parts of the foot are able to realize inversion and eversion independently.

[0014] Another possible embodiment of the invention is characterized in that the inversion / eversion mechanism comprises at least one inversion / eversion guide slot, at least one of the front base, and the rear base comprises at least one connection extension slidably connected within said inversion / eversion guide slot, at least one of the two opposite sides of said connection extension is connected to the centering spring. Thus, when the foot is raised from an inclined surface, the base parts are again perpendicular to the tibia. In other words, the extension part returns to the origin position in the middle of the inversion / eversion guide slot.

[0015] Another possible embodiment of the invention is characterized in that the inversion / eversion mechanism comprises at least one motorized drive element to provide control of the movements of the connection extension within the inversion / eversion guide slot. Thus, inversion and eversion movements are controlled electronically instead of mechanically.

[0016] Another possible embodiment of the invention is characterized in that said inversion / eversion guide slot has a first arc form. Thus, it is ensured that the foot base can perform the inversion and eversion movements in the most realistic way.

[0017] Another possible embodiment of the invention is characterized in that said sliding guide slot has a second arc form. Thus, when the motorized spring slides in the sliding guide slot, it is ensured that it can give the forward thrust during push-off from the ground.

[0018] BRIEF DESCRIPTION OF THE FIGURES

[0019] Figure 1 shows a representative perspective view of the ankle prosthesis of the invention.

[0020] Figure 2 shows a representative frontal view of the ankle prosthesis of the invention.

[0021] Figure 3 shows a representative side view of the ankle prosthesis of the invention.

[0022] DETAILED DESCRIPTION OF THE INVENTION In this detailed description, the subject matter of the invention is explained only by means of examples that will not have any limiting effect for a better understanding of the subject matter.

[0023] Figure 1 shows a representative perspective view of the ankle prosthesis (10) of the invention. Said ankle prosthesis (10) provides an imitation of the mimics of the foot and ankle during a person's walking movement. Accordingly, the ankle prosthesis (10) is indicated for use by people with amputation below the knee and humanoid robots. The ankle prosthesis (10) includes at least one foot part (30) and at least one tibia part (20). While the foot part (30) serves as a foot prosthesis, the tibia part (20) allows the foot part (30) to be connected to the upper side of the leg of the amputee or humanoid robot. At the same time, the tibia part (20) may also enable the ankle prosthesis (10) to be connected with another prosthesis (e.g., knee prosthesis).

[0024] The tibia part (20) has at least one main body (21 ). The main body (21 ) is the rigid skeleton of the tibia part (20). The tibia part (20) comprises at least one motorized spring (22). Said motorized spring (22) comprises at least one first motor (221 ) and at least one first spring (222). The motorized spring (22) is connected to the foot part (30) at one end and to the upper part of the leg at the other end. Accordingly, by storing energy on the first spring (222), the necessary push-off for walking can be obtained. The first motor (221 ) may be driven to compress the first spring (222). Thus, energy is stored in the first spring (222).

[0025] If the walking movement is considered as a cycle, it can be said that it basically consists of grounding, push-off, and swing motions. Stepping on the ground is the interval between the moment when the heel part of the foot first touches the ground and the moment when the sole of the foot is completely stepping on the ground. Push-off is the interval between the moment when the sole is completely pressed against the ground and the moment when the toe is completely off the ground. The need for power arises during this time. The swing phase, on the other hand, defines the swing motion below the knee for the next step. The first motor (221 ) compresses the first spring (222) during gait cycle, except push-off phase, allowing energy to be stored on the first spring (222). The stored energy is released during the push-off phase. Thus, the thrust of the foot part (30) needed for the realization of walking is provided in accordance with the natural ankle. As a result, the transition to the swing phase of the gait is provided.

[0026] The foot part (30) comprises at least one front base (311 ) and at least one rear base (321 ). The front base (31 1 ) and the rear base (321 ) are parts that allow the ankle prosthesis (10) to come into contact with the ground. The front base (311 ) defines around the toe of the sole of the foot. The rear base (321 ) defines the heel part of the foot base. The foot part (30) comprises at least one inversion / eversion mechanism (50). The inversion / eversion mechanism (50) ensures that the foot part (30) is capable of performing inversion and eversion movements. Inversion and eversion movements define the inward rotation of the sole of the foot and the outward rotation of the sole of the foot, respectively. According to the ankle prosthesis (10) subject to the invention, the front base (311 ) and the rear base (321 ) are each connected with at least one inversion / eversion mechanism (50).

[0027] The inversion / eversion mechanism (50) comprises at least one inversion / eversion guide slot (51 ). The inversion / eversion guide slot (51 ) is configured to receive a connection extension (33). The connection extension (33) is an extension located on at least one of the front bases (31 1 ) and the rear base (321 ) to allow the foot part (30) to be connected to the inversion / eversion mechanism (50). Accordingly, the front connection extension (33) at the front base (311 ) is located in the inversion / eversion guide slot (51 ) of the inversion / eversion mechanism (50) located at the front part (31 ). The front connection extension (33) can make sliding movement within the inversion / eversion guide slot (51 ). The rear connection extension (33) on the rear base (321 ) is located in the guide slot of the inversion / eversion mechanism (50) in the heel part (32). The rear connection extension (33) can slip within the inversion / eversion guide slot (51 ).

[0028] The inversion / eversion guide slot (51 ) has a first arc form (I). Said first arc form (I) defines the pile-up of the inversion / eversion guide slot (51 ) towards the ground where the sole of the foot contacts. The inversion / eversion guide slot (51 ) associated with the front connection extension (33) and the inversion / eversion guide slot (51 ) associated with the rear connection extension (33) may be identical to each other in a possible embodiment of the invention and may have a first arc form (I) of different sizes from each other in another possible embodiment.

[0029] The connection extension (33) is connected with at least one centering spring (52) at two opposite ends. The centering springs (52) ensure that the movement of the front connection extension (33) within the inversion / eversion guide slot (51 ) is controlled. Accordingly, for example, when the front connection extension (33) moves within the inversion / eversion guide slot (51 ), the centering spring (52) in the direction in which the connection extension (33) travels is compressed, and the centering spring (52) on the other side is tensioned. Thanks to this structure, it is ensured that the base is perpendicular to the tibia part (20) again when the foot is lifted from the ground. In an exemplary working scenario, the movement of the rear connection extension (33) within the inversion / eversion guide slot (51 ) is essentially accomplished by pressing the rear base (321 ) on a slope or uneven surface. Accordingly, when the rear base (321 ) presses against an inclined ground, the rear connection extension (33) slides within the inversion / eversion guide slot (51 ). In this way, the rear base (321 ) can be parallel to the inclined surface, while the tibia part (20) can remain perpendicular to the ground. The same applies to the front base (31 1 ). Accordingly, the front base (311 ) can become parallel to the surface it presses when it presses on a slope thanks to the inversion / eversion mechanism (50). Thanks to the structure of the inversion / eversion mechanism (50), the rest of the foot part (30) can remain upright without being affected by this inclined surface.

[0030] The inversion / eversion mechanism (50) may be driven and controlled by a motorized drive element in a possible embodiment of the invention. In this way, the inversion and eversion movements of the sole of the foot can be controlled electronically. Thanks to the fact that the ankle prosthesis (10), which is the subject of the invention, has individual inversion / eversion mechanisms (50) for the front base (311 ) and the rear base (321 ), it allows the finger part of the foot and the heel parts to make inversion and eversion independent from each other.

[0031] The ankle prosthesis (10) is configured to allow dorsiflexion and plantar flexion movements. The dorsiflexion movement is essentially the bending of the ankle towards the leg. The plantar flexion movement is the bending movement of the ankle in the opposite direction of the dorsiflexion. In other words, in plantar flexion, the ankle is bent toward the floor.

[0032] Dorsiflexion and plantar flexion movements can be performed with at least one dorsiflexion element (60). The dorsiflexion element (60) is connected between a front part (31 ) of the foot part (30) and a heel part. There are multiple dorsiflexion elements (60) in a preferred embodiment of the invention. The dorsiflexion element (60) is connected to at least one dorsiflexion channel (62) in the heel part.

[0033] The dorsiflexion element (60) comprises at least one dorsiflexion spring (61 ). Said dorsiflexion spring (61 ) serves as energy storage on itself for the push-off phase of the foot. Accordingly, the dorsiflexion spring (61 ) elongates during the plantar flexion movement and compresses during the dorsiflexion movement. The control of the ankle torque and moment is carried out by the movement of the dorsiflexion element (60). Accordingly, when the end of the dorsiflexion spring (61 ) in the dorsiflexion guide slot moves away from the ground, the ankle moment decreases and increases in the opposite case. The dorsiflexion element (60) is connected with at least one second motor (40). The second motor (40) can control the tension of the dorsiflexion spring (61 ) in the dorsiflexion element (60). The moment of the ankle can be controlled according to the dorsiflexion movement. Accordingly, the second motor (40) is essentially connected with the dorsiflexion element (60) in the heel part. There is at least one drive transmission element (41 ) that provides drive transmission between the second motor (40) and the dorsiflexion element (60). With the second motor (40), the movement of the dorsiflexion springs during walking is controlled by the guide according to the required moment and ankle movement. Thus, it is ensured that dorsiflexion and plantar flexion movements are more controlled during walking.

[0034] The ankle prosthesis (10) includes at least one sliding mechanism (70). The sliding mechanism (70) is connected to the motorized spring (22). The sliding mechanism (70) allows the motorized spring (22) to be moved in a sliding trajectory (a). The sliding trajectory (a) has a second arc form (II), which curves towards the ground. The movement and moment of the ankle are controlled by returning the energy to the motorized spring (22). Thus, the ankle torque is controlled according to the natural ankle angle.

[0035] The sliding mechanism (70) comprises at least one sliding guide slot (71 ) into which one end of the motorized spring (22) is coupled. Accordingly, the end of the motorized spring (22) in the sliding guide slot (71 ) can make sliding movement in the sliding guide slot (71 ). The sliding guide slot (71 ) is configured with a second arc form (II) in accordance with the sliding trajectory (a). In this context, the end of the motorized spring (22) in the sliding guide slot (71 ) can move in the sliding trajectory (a).

[0036] The motorized spring (22) is connected to the second motor (40). The second motor (40) provides control of the movement of the motorized spring (22) in the sliding trajectory (a). The end of the motorized spring (22) in the sliding guide slot (71 ) is moved in the first direction (+a) in the sliding trajectory (a) during the push-off. This movement is provided by the second motor (40). The first direction (+a) is the direction in which the trajectory rises relative to the ground and extends from the front part (31 ) to the heel part (32). The second motor (40) is connected to both the dorsiflexion element and the sliding mechanism; thus these two mechanisms are controlled by a single motor. In this way, an easy-to-control, compact, and lightweight ankle prosthesis is presented.

[0037] Thanks to the fact that the end of the motorized spring (22) in the sliding guide slot (71 ) is moved in the first direction (+a) during push-off, the direction of the push-off force exerted by the first spring (222) also change, and the push-off phase can be carried out by taking the maximum level of support from the front base for stepping (311 ).

[0038] The protection scope of the invention is specified in the appended claims and cannot be strictly limited to those explained in this detailed description for illustrative purposes. It is evident that a person skilled in the art may exhibit similar embodiments in light of the foregoing without departing from the main theme of the invention.

[0039] REFERENCE NUMBERS GIVEN IN THE FIGURE

[0040] 10 Ankle Prosthesis

[0041] 20 Tibia Part

[0042] 21 Main Body

[0043] 22 Motorized Spring

[0044] 221 First Motor

[0045] 222 First Spring

[0046] 30 Foot Part

[0047] 31 Front Part

[0048] 311 Front Base

[0049] 32 Heel Part

[0050] 321 Rear Base

[0051] 33 Connection Extension

[0052] 40 Second Motor

[0053] 41 Drive Transmission Element

[0054] 50 Inversion / Eversion Mechanism

[0055] 51 Inversion / Eversion Guide Slot

[0056] 52 Centering Spring

[0057] 60 Dorsiflexion Element

[0058] 61 Dorsiflexion Spring

[0059] 62 Dorsiflexion Channel

[0060] 70 Sliding Mechanism

[0061] 71 Sliding Guide Slot

[0062] (a) Sliding Trajectory

[0063] (+a) First Direction

[0064] (I) First Arc Form

[0065] (II) Second Arc Form

Claims

CLAIMS1 . The invention is an ankle prosthesis (10) comprising at least one tibia part (20) comprising at least one first spring (222) and at least one motorized spring (22) with at least one first motor (221 ) enabling compression of said first spring (222), and comprising at least one foot part (30) with at least one front base (31 1 ) and at least one rear base (321 ) providing contact with the ground, at least one inversion / eversion mechanism (50) to ensure the eversion and inversion movements of the ankle; comprising at least one dorsiflexion element (60) with at least one dorsiflexion spring (61 ) extending from the front base (31 1 ) to the rear base (321 ) to provide dorsiflexion and plantar flexion movements of the ankle, characterized in that one end of said motorized spring (22) is connected to at least one sliding guide slot (71 ) to enable it to be moved in at least one sliding trajectory (a), that it comprises at least a second motor (40) controlling the sliding movement of the motorized spring (22) within the said sliding guide slot (71 ), as well as controlling the compression of the said dorsiflexion spring (61 ).

2. An ankle prosthesis (10) according to Claim 1 , characterized in that it comprises at least one inversion / eversion mechanism (50) operating independent from each other for the front base (311 ) and the rear base (321 ) in a front part (31 ) and a heel part (32) of the foot part (30).

3. An ankle prosthesis (10) according to Claim 1 , characterized in that the inversion / eversion mechanism (50) comprises at least one inversion / eversion guide slot (51 ), at least one of the front base (31 1 ), and the rear base (321 ) comprises at least one connection extension (33) slidably connected within said inversion / eversion guide slot (51 ), and the said connection extension is connected with at least one centering spring (52) from two opposite sides.

4. An ankle prosthesis (10) according to Claim 3, characterized in that the inversion / eversion mechanism (50) comprises at least one motorized drive element to control the movements of the connection extension (33) within the inversion / eversion guide slot (51 ).

5. The ankle prosthesis (10) according to Claim 3, characterized in that said inversion / eversion guide slot (51 ) has a first arc form (I).

6. The ankle prosthesis (10) according to Claim 1 , characterized in that said sliding guide slot (71 ) has a second arc form (II).

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