Passive bionic ankle-foot prosthesis

Abstract

Disclosed is a passive bionic ankle-foot prosthesis, comprising a lower leg connecting rod, a lower leg connector, a lower leg fixing tube, a sole fixing and connecting apparatus, a lower leg slider, a damper, an elastic element, a prosthetic foot plate, and an energy recovery apparatus. The lower leg connecting rod is hinged to the sole fixing and connecting apparatus to form a prosthetic ankle joint. The damper and the elastic element are connected in parallel. When the ankle joint rotates, the damper provides damping for adjusting the bending and extending speed of the ankle joint, and the elastic element provides support and pushing torque in the states of plantarflexion, dorsiflexion, and pushing. The prosthetic foot plate is used for reducing impact when the prosthesis contacts the ground, and the sole fixing and connecting apparatus is connected to the prosthetic foot plate. The energy recovery apparatus is used for converting part of the elastic deformation of the prosthetic foot plate and the elastic element into electric energy. The present invention can well mimic the biomechanical characteristics of the human ankle joint, providing flexibility and a natural feel during walking, thereby improving walking stability and efficiency.

Description

A passive bionic ankle-foot prosthesis Technical Field

[0001] This invention belongs to the field of prosthetics technology and relates to a passive bionic ankle-foot prosthesis. Background Technology

[0002] Ankle-foot prostheses are an important component of lower limb prostheses and play a vital role in improving the quality of life for amputees. Ankle-foot prostheses mainly consist of an ankle joint prosthesis and a prosthetic footplate.

[0003] Ankle prostheses on the market are currently divided into two types: active and passive, each with its own advantages and limitations. Active ankle prostheses, through built-in motors or hydraulic devices, can automatically adjust the movement of the ankle joint, simulating the ankle movements of a normal person walking. However, these active ankle prostheses are usually heavy, increasing the burden on the wearer, and are also expensive, energy-intensive, requiring regular maintenance. Their reliance on batteries also limits their ease of use. Furthermore, although active ankle prostheses can simulate real ankle movements, they still cannot completely replicate the biomechanical characteristics of the human body. In contrast, passive ankle prostheses are simpler, typically relying on material elasticity and mechanical design for support. These prostheses are lightweight, low-cost, and easy to maintain. However, current passive ankle prostheses cannot perfectly mimic the biomechanical characteristics of the human ankle joint, resulting in a lack of flexibility and naturalness when walking, affecting walking stability and efficiency.

[0004] Furthermore, most existing prosthetic footplates are based on the skeletal features of the human foot, lacking a reference to the overall three-dimensional structure of the foot. The "winch mechanism" is a mechanical model describing how the plantar fascia supports the foot, playing a crucial role in the storage and release of energy during walking. A "winch" refers to the action of tightening a rope or cable. The plantar fascia simulates a cable attached to the calcaneus and metatarsophalangeal joint. During the propulsion phase of gait, when dorsiflexion occurs, the plantar fascia wraps around the metatarsal heads. This wrapping action shortens the distance between the calcaneus and metatarsals, thereby strengthening the medial longitudinal arch. However, recent domestic and international research indicates that most of the intrinsic plantar muscles are connected proximally to the plantar surface of the calcaneus and distally to the toes. During contraction, they resist the compression of the longitudinal arch, similar to the resistance provided by the plantar fascia during toe dorsiflexion. The plantar muscles and plantar fascia together constitute the "winch mechanism," playing a vital role in energy storage and propulsion during walking.

[0005] Summary of the Invention

[0006] In view of this, the present invention provides a passive bionic ankle-foot prosthesis, wherein the lower leg link and the foot fixing connection device are hinged to form a prosthetic ankle joint, and a damper and an elastic element are connected in parallel. When the ankle joint rotates, the damper provides damping to adjust the flexion and extension speed of the ankle joint, and the elastic element provides support and pushing torque in plantar flexion, dorsiflexion and pushing states, thereby mimicking the function of the human ankle joint.

[0007] To address the aforementioned problems, embodiments of the present invention provide a passive bionic ankle-foot prosthesis for assisting lower limb amputees in achieving walking function, characterized by:

[0008] It includes a lower leg connecting rod, a lower leg fixing tube, and a foot fixing connection device. The lower leg connecting rod is connected to the lower leg fixing tube, and the lower leg fixing tube is hinged to the foot fixing connection device to form a prosthetic ankle joint.

[0009] The lower leg connector is connected to the lower leg link and is used to connect to the receiving cavity of the prosthesis patient or the knee prosthesis.

[0010] The lower leg slider can slide up and down along the connecting rod;

[0011] A damper, one end of which is hinged to the lower leg slider and the other end of which is hinged to the foot fixing connection device, is used to adjust the bending and extension speed of the ankle-foot prosthesis during rotation around the prosthesis ankle joint, and at the same time can prevent the ankle-foot prosthesis from shaking.

[0012] An elastic element, which is connected in parallel with a damper, is compressed or released when the lower leg link and the foot fixing connection device rotate around the prosthetic ankle joint;

[0013] The prosthetic footplate includes an elastic forefoot and an elastic heel portion, which are used to reduce the impact force during the contact between the prosthesis and the ground. The foot fixing connection device is connected to the prosthetic footplate.

[0014] An energy recovery device is used to convert partial elastic deformation of the prosthetic footplate and elastic element into electrical energy.

[0015] Furthermore, the lower leg slider is a linear bearing to reduce friction during movement; the length of the lower leg connecting rod can be adjusted according to the actual needs of the amputee patient, and the material of the lower leg connecting rod is carbon fiber tube or metal tube.

[0016] Furthermore, the damper is a hydraulic or pneumatic damper;

[0017] Alternatively, the damper is a magnetorheological damper, and the damping provided by the damper can be actively adjusted by controlling the excitation current of the damper;

[0018] Alternatively, the damper is a motor coupled with a ball screw drive. By controlling the motor to actively adjust the damping provided by the damper, the motor can be used as a generator to recover energy.

[0019] Furthermore, the motor can be used as a driver in some states to provide driving torque.

[0020] Furthermore, the elastic element is a type of tension and compression spring, comprising upper and lower parts. When the calf link and the foot foot fixing connection device rotate around the ankle joint, the calf slider slides along the leg exercise link, and the elastic element is stretched or compressed, while providing support or pushing torque.

[0021] Furthermore, the upper and lower parts of the spring have different spring stiffnesses to mimic the stiffness of the human ankle joint during plantar flexion, dorsiflexion, and propulsion phases.

[0022] Furthermore, the elastic element is a leaf spring. When the lower leg connecting rod and the foot foot fixing connection device rotate around the ankle joint, the lower leg slider slides along the lower leg connecting rod, and the elastic element deforms, while providing support or pushing torque.

[0023] Furthermore, one end of the leaf spring is fixed to the foot fixing connection device, and the other end is either fixedly connected or hinged to the calf slider;

[0024] Alternatively, one end of the leaf spring may be fixedly or hinged to the foot fixing device, and the other end may be fixed to the calf slider.

[0025] Furthermore, the leaf spring is a specially customized curved spring, and the shape and thickness of the curved surface can be specially designed to mimic the support and propulsive torque provided by the human body during plantar flexion, dorsiflexion, and propulsion phases.

[0026] Furthermore, the rear part of the elastic forefoot of the prosthetic footplate is fixed between the connector and the elastic heel. The elastic forefoot is used to mimic the longitudinal arch of the human foot, bear the body weight, and absorb the impact generated when the amputee walks.

[0027] Furthermore, the upper part of the elastic heel of the prosthetic footplate is fixedly connected to the lower part of the elastic forefoot. The elastic heel is used to mimic the heel of the human foot, absorbing the impact force of the ground during walking, while supporting the body weight and maintaining balance.

[0028] Furthermore, an energy recovery device is bonded to the elastic forefoot and elastic heel. The energy recovery device is a flexible piezoelectric material and a flexible triboelectric material, used to convert part of the elastic deformation of the foot into electrical energy to power the prosthetic sensor and communication device.

[0029] Furthermore, the energy recovery device outputs voltage or current to analyze the walking status of the prosthesis, including one or more of walking speed, walking cadence, walking time, and standing time.

[0030] Furthermore, the elastic element is bonded to an energy recovery device, which is a flexible piezoelectric material and a flexible triboelectric material, used to convert partial deformation of the elastic element into electrical energy to power the prosthetic sensor and communication device.

[0031] Furthermore, the energy recovery device outputs voltage or current to analyze the bending angle and supporting torque of the prosthesis.

[0032] Compared with the prior art, the passive bionic ankle-foot prosthesis of the present invention has at least the following beneficial effects:

[0033] 1. In this invention, the lower leg link and the foot fixing connection device are hinged to form a prosthetic ankle joint. The damper and the elastic element are connected in parallel. When the ankle joint rotates, the damper provides damping to adjust the flexion and extension speed of the ankle joint. The elastic element provides support and pushing torque in plantar flexion, dorsiflexion and pushing states, thereby mimicking the function of the human ankle joint.

[0034] 2. In this invention, the prosthetic footplate is modeled after the role of human foot muscles in walking, utilizing its biomimetic structural principle to reduce the impact force between the prosthesis and the ground. During dynamic walking, when the heel strikes the ground and the forefoot lifts off, the elastic heel and elastic components of the footplate stretch and store energy; as the forefoot lands and the heel lifts off the ground, the energy stored in the heel and elastic components is transferred to the forefoot plate to support and propel the body forward, entering the next gait phase.

[0035] 3. The energy recovery device in this invention can convert the deformation of the foot and the leaf spring into electrical energy, thereby powering the prosthesis sensor to monitor the walking status of the prosthesis and the prosthesis wearer.

[0036] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 is an isometric view (left front view) of an embodiment of the present invention;

[0039] Figure 2 is an isometric view (left front view) of Embodiment 2 of the present invention;

[0040] Figure 3 is a structural schematic diagram of a calf connector according to an embodiment of the present invention;

[0041] Figure 4 is a schematic diagram of the structure of a lower leg connecting rod according to an embodiment of the present invention;

[0042] Figure 5 is a schematic diagram of the structure of a calf slider according to an embodiment of the present invention;

[0043] Figure 6 is a schematic diagram of the structure of a damper according to an embodiment of the present invention;

[0044] Figure 7 is a schematic diagram of the structure of an elastic element according to an embodiment of the present invention;

[0045] Figure 8 is a schematic diagram of the structure of a calf fixation tube according to an embodiment of the present invention;

[0046] Figure 9 is a structural schematic diagram of a foot fixing connection device according to an embodiment of the present invention;

[0047] Figure 10 is a schematic diagram of the structure of the prosthetic footplate in an embodiment of the present invention;

[0048] Figure 11 is a schematic diagram of the ankle joint angle during normal human walking;

[0049] Figure 12 is a schematic diagram of ankle joint torque during normal human walking;

[0050] Figure 13 is a schematic diagram of the ground reaction force during normal human walking;

[0051] in:

[0052] 1. Lower leg connector, 1a. Connector top, 1b. Arc surface, 1c. Through hole,

[0053] 2. Lower leg connecting rod, 2a. Upper end of lower leg connecting rod, 2b. Lower leg connecting rod bottom end,

[0054] 3. Lower leg slider, 3a. Through hole, 3b. Middle through hole, 3c. Shaft hole,

[0055] 4. Damper, 4a. Through hole, 4b. Damper shaft, 4c. Damper tube, 4d. Through hole

[0056] 5. Elastic element, 5a. Top through hole, 5b. Leaf spring, 5c. Bottom through hole, 6. Lower leg fixing tube, 6a. Blind hole, 6b. Through hole, 6c. Through hole,

[0057] 7. Foot fixing connection device, 7a. shaft hole, 7b. through hole, 7c. shaft hole,

[0058] 8. Prosthetic footplate, 8a. Connector, 8b. Flexible heel, 8c. Flexible component, 8d. Flexible forefoot.

[0059] 9. Energy recovery device. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. This invention is intended for wider application in socket-type heating pipes; therefore, it can be used in any practical application requiring suitability for a particular application.

[0061] Referring to Figures 1 and 2, this invention proposes a passive bionic ankle-foot prosthesis to assist lower limb amputees in achieving walking function, including a lower leg connector 1, a lower leg link 2, a lower leg slider 3, a damper 4, an elastic element 5, a lower leg fixation tube 6, a prosthetic foot plate 8, an energy recovery device 9, and a foot fixation connection device 7.

[0062] The lower end of the lower leg connecting rod 2 is connected to the lower leg fixing tube 6, and the lower leg fixing tube 6 is hinged to the foot fixing connection device 7 to form a prosthetic ankle joint. The lower leg connector 1 is connected to the upper end of the lower leg link 2, and the lower leg connector 1 is used to connect to the receiving cavity of the prosthesis patient or the knee joint prosthesis; the lower leg slider 3 is sleeved on the lower leg link 2 and can slide up and down along the lower leg link 2; the damper 4 is located on the front side of the prosthesis, one end of the piston rod of the damper 4 is hinged to the lower leg slider 3, and the other end of the outer shell of the damper 4 is hinged to the foot fixing connection device 7; the elastic element 5 is located on the rear side of the prosthesis and is connected in parallel with the damper 4. When the lower leg link 2 and the foot fixing connection device 7 rotate around the ankle joint of the prosthesis, the elastic element 5 is compressed or released; the prosthesis footplate 8 includes an elastic forefoot 8d and an elastic heel 8b, which are used to reduce the impact force during the contact between the prosthesis and the ground, and the bottom of the foot fixing connection device 7 is connected to the prosthesis footplate 8; the energy recovery device 9 is used to convert part of the elastic deformation of the prosthesis footplate 8 and the elastic element into electrical energy.

[0063] Specifically, the length of the lower leg connecting rod 2 can be adjusted according to the actual needs of the amputee patient, and the material of the lower leg connecting rod 2 can be either carbon fiber tube or metal tube.

[0064] Specifically, the lower leg slider 3 can be a linear bearing, which is mounted on the lower leg connecting rod 2 and can slide up and down along the lower leg connecting rod 2. The linear bearing is used to reduce friction during movement.

[0065] In this invention, the damper 4 is used to adjust the bending and extension speed of the ankle-foot prosthesis during rotation around the ankle joint of the prosthesis, and at the same time, it can prevent the ankle-foot prosthesis from shaking.

[0066] Specifically:

[0067] The damper 4 can be one of a traditional hydraulic or pneumatic damper.

[0068] The damper 4 can also be a magnetorheological damper, and the damping provided by the damper can be actively adjusted by controlling the excitation current of the damper 4.

[0069] The damper 4 can also be a motor coupled with a ball screw drive. By controlling the motor to actively adjust the damping provided by the damper, the motor can be used as a generator to recover energy. As a preferred embodiment, the motor can be used as a driver to provide driving torque in some states.

[0070] In some embodiments provided by the present invention, the elastic element 5 is a type of conventional tension and compression spring, comprising upper and lower parts. When the calf connecting rod 2 and the foot fixing connection device 7 rotate around the ankle joint, the calf slider 3 slides along the leg-stretching connecting rod, and the elastic element 5 is stretched or compressed, while providing support or pushing torque.

[0071] As a preferred embodiment of the present invention, the upper and lower parts of the spring are provided with different stiffnesses to mimic the stiffness of the human ankle joint during plantar flexion, dorsiflexion, and propulsion phases.

[0072] As a preferred embodiment of the present invention, referring to Figure 7, the elastic element 5 can be a customized leaf spring. When the calf link 2 and the foot fixing connection device 7 rotate around the ankle joint, the calf slider 3 slides along the leg exercise link, and the elastic element 5 deforms, while providing support or pushing torque.

[0073] The leaf spring is a specially customized curved spring, and the shape and thickness of the curved surface can be specially designed to mimic the support and propulsive torque provided by the human body during plantar flexion, dorsiflexion and propulsion phases.

[0074] Specifically, one end of the leaf spring is fixed to the foot fixing connection device 7, and the other end of the leaf spring is either fixedly connected or hinged to the calf slider 3; or, the leaf spring is fixed to the calf slider 3, and the other end is either fixedly connected or hinged to the foot fixing device.

[0075] Specifically, referring to Figure 10, the elastic forefoot 8d and elastic heel 8b of the prosthetic footplate 8 are both curved plate structures. Their rear parts are connected and fixed between the connector 8a and the elastic heel 8b. The elastic forefoot 8d mimics the longitudinal arch of the human foot, bearing body weight and absorbing the impact generated when the amputee walks. The upper part of the elastic heel 8b is fixedly connected to the lower part of the elastic forefoot 8d. The elastic heel 8b mimics the heel of the human foot, absorbing ground impact during walking while supporting body weight and maintaining balance.

[0076] In some embodiments provided by the present invention, referring to Figure 9, the lower part of the prosthetic footplate 8 is bonded with an energy recovery device 9. The energy recovery device 9 is a flexible piezoelectric material and a flexible triboelectric material, which is used to convert part of the elastic deformation of the footplate into electrical energy to power the prosthetic sensor and communication device.

[0077] The voltage or current output by the energy recovery device 9 at the lower part of the prosthetic footplate 8 can be used to analyze the walking status of the prosthesis, including one or more of walking speed, walking cadence, walking time, and standing time.

[0078] In some embodiments provided by this invention, referring to Figure 5, an energy recovery device 9 is bonded to the elastic element 5. The energy recovery device 9 is a flexible piezoelectric material and a flexible triboelectric material, used to convert partial deformation of the elastic element 5 into electrical energy to power the prosthetic sensor and communication device. The voltage or current output by the energy recovery device 9 is used to analyze the bending angle and supporting torque of the prosthesis.

[0079] As shown in Figures 1 and 2, this invention proposes a passive bionic ankle-foot prosthesis, comprising a calf connector 1, a calf link 2, a calf slider 3, a damper 4, an elastic element 5, a calf fixation tube 6, a foot fixation connection device 7, and a prosthetic footplate 8. As shown in Figures 3 and 4, the calf connector 1 is connected to the prosthetic receiving cavity, with its arc surface 1b contacting the receiving cavity. The calf connector 1 is connected to the calf link 2 via a through hole 1c and the upper end 2a of the calf link 2 using screws or other fixing methods. As shown in Figures 5 and 6, the through hole 3b of the calf slider is fitted onto the calf link 2 and can move up and down along it. The damper 4 is hinged to the sleeve shaft hole 3c via a through hole 4b and can rotate with plantar flexion and dorsiflexion movements of the human body. As shown in Figure 7, the elastic element 5 is connected and fixed to the through hole 3a of the lower leg slider through the through hole 5a. In addition, as shown in Figure 2, two lower leg connecting rods 2 are provided, which are symmetrical from left to right. The lower leg slider 3 is sleeved on the lower leg connecting rod 2, and springs are sleeved on both the lower leg connecting rod 2 in the vertical direction of the lower leg slider 3.

[0080] As shown in Figures 6 and 9, the damper 4 can extend and retract with the plantar flexion and dorsiflexion of the human body. The lower end of the damper 4 is hinged to the shaft hole 7c of the foot fixing connection device through the through hole 4a. The lower end of the elastic element 5 is fixed to the through hole 7b of the foot fixing connection device through the through hole 5c. As shown in Figure 8, the bottom end 2b of the lower leg connecting rod is placed in the blind hole 6a of the lower leg fixing tube 6 and fixed through the through hole 6b using screws or other connection methods. The through hole 6c of the lower leg fixing tube is connected to the shaft hole 7c of the foot fixing connection device. The lower leg fixing tube 6 can rotate around the shaft hole 7c with the plantar flexion and dorsiflexion of the human body. As shown in Figure 10, the connector 8a of the prosthetic foot plate 8 is connected to the foot fixing connection device 7 through the through hole 7b of the foot fixing connection device. The elastic component 8c is located below the prosthetic foot plate 8, with one end connected to the elastic heel 8b and the other end connected to the elastic forefoot 8d. The ankle joint angle, torque curve, and ground reaction force measured after wearing the invention should be similar to those shown in Figures 11-13.

[0081] Furthermore, it should be noted that the passive ankle-foot prosthesis designed in this invention can be used in the design of human lower limb prostheses to help amputees walk, or in bipedal walking robots, etc., to achieve humanoid walking function.

[0082] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A passive bionic ankle foot prosthesis, characterized in that, The invention relates to a prosthetic ankle joint, comprising: a shank link, a shank fixed tube and a foot fixed connecting device, the shank link is connected with the shank fixed tube, the shank fixed tube is hinged with the foot fixed connecting device, forming a prosthetic ankle joint; a shank connector, the shank connector is connected with the shank link, used for connecting with the receiving cavity of the prosthetic patient or the knee joint prosthesis; a shank slider, the shank slider is slidable up and down along the shank link; a damper, one end of the damper is hinged with the shank slider, the other end of the damper is hinged with the foot fixed connecting device, the damper is used for adjusting the bending and stretching speed of the ankle-foot prosthesis during rotation around the prosthetic ankle joint; a spring element, the spring element is connected in parallel with the damper, when the shank link and the foot fixed connecting device rotate around the prosthetic ankle joint, the spring element is compressed or released; a prosthetic foot plate, the prosthetic foot plate contains a flexible forefoot and a flexible heel part, used for reducing the impact force during the contact between the prosthesis and the ground, the foot fixed connecting device is connected with the prosthetic foot plate; an energy recovery device, the energy recovery device is used for converting the partial elastic deformation of the prosthetic foot plate and the spring element into electrical energy.

2. The passive bionic ankle foot prosthesis of claim 1, characterized in that: The shank slider is a linear bearing; the length of the shank link can be adjusted according to actual needs, and the material of the shank link is a carbon fiber tube or a metal tube.

3. The passive bionic ankle foot prosthesis of claim 1, wherein: The damper is a hydraulic or pneumatic damper; Alternatively, the damper is a magneto-rheological damper, the damping provided by the damper is actively adjusted by controlling the excitation current of the damper; Alternatively, the damper is a motor cooperating with a ball screw transmission, the damping provided by the damper is actively adjusted by controlling the motor, at this time the motor can be used as a generator to recover energy.

4. The passive bionic ankle foot prosthesis of claim 3, characterized in that: The motor can be used as a driver to provide driving torque in some states.

5. The passive bionic ankle foot prosthesis of claim 1, wherein: The spring element is one of a tensile spring and a compression spring, containing upper and lower parts, when the shank link and the foot fixed connecting device rotate around the ankle joint, the shank slider slides along the shank link, the spring element is stretched or compressed, and at the same time a support or pushing torque is provided.

6. The passive bionic ankle foot prosthesis of claim 5, characterized in that: The spring stiffness of the upper and lower parts of the spring is different, used for simulating the stiffness of the corresponding plantar flexion, dorsiflexion and pushing stage of the human ankle joint.

7. The passive bionic ankle foot prosthesis according to claim 1, characterized in that: The spring element is a leaf spring, when the shank link and the foot fixed connecting device rotate around the ankle joint, the shank slider slides along the shank link, the spring element is deformed, and at the same time a support or pushing torque is provided.

8. The passive bionic ankle foot prosthesis of claim 7, characterized in that: One end of the leaf spring is fixed with the foot fixed connecting device, and the other end is one of fixed connection or hinged connection with the shank slider; Alternatively, one end of the leaf spring is one of fixed connection or hinged connection with the foot fixed device, and the other end is fixed with the shank slider.

9. The passive bionic ankle foot prosthesis of claim 7, characterized in that: The leaf spring is a curved surface spring, used for simulating the support and pushing torque provided by the human body in the plantar flexion, dorsiflexion and pushing stage.

10. The passive bionic ankle foot prosthesis of claim 1, wherein: The rear part of the flexible forefoot of the prosthetic foot plate is fixed between the connector and the flexible heel, and the flexible forefoot is used for simulating the longitudinal arch of the human foot, bearing the body weight, and absorbing the impact generated when the amputee walks.

11. The passive bionic ankle foot prosthesis of claim 1, wherein: The elastic rear heel upper part of the artificial foot plate is fixedly connected with the lower part of the elastic front sole, the elastic rear heel is used for imitating the heel of human foot, absorbing the ground impact force during walking, supporting the body weight and maintaining balance.

12. The passive bionic ankle foot prosthesis of claim 1, wherein: The elastic front sole and the elastic rear heel upper part are bonded with energy recovery devices, the energy recovery devices are flexible piezoelectric material and flexible friction power generation material, which are used for converting partial elastic deformation of the foot plate into electric energy to power the artificial limb sensors and communication devices.

13. The passive bionic ankle foot prosthesis of claim 12, characterized in that: The energy recovery devices output voltage or current, which are used for analyzing the walking state of the artificial limb, including one or more of walking speed, walking step frequency, walking time and standing time.

14. The passive bionic ankle foot prosthesis of claim 1, wherein: The elastic element is bonded with energy recovery devices, the energy recovery devices are flexible piezoelectric material and flexible friction power generation material, which are used for converting partial deformation of the elastic element into electric energy to power the artificial limb sensors and communication devices.

15. The passive bionic ankle foot prosthesis of claim 14, wherein, The energy recovery devices output voltage or current, which are used for analyzing the bending angle and support torque of the artificial limb.

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