Prosthetic foot toe component with ground environment sensing capability and method of making

Abstract

The application provides a prosthetic foot toe component with ground environment detection capability and a preparation method thereof, wherein the prosthetic foot toe component comprises: a bottom tactile sensing layer comprising a transparent elastomer containing microparticles, which is used for converting external force into spatial displacement of the microparticles; a shooting module mainly comprising a micro RGB camera and an LED lamp plate, the micro RGB camera is used for capturing the optical flow characteristics of the microparticles when the bottom tactile sensing layer is subjected to force, and converting the optical flow characteristics into an optical flow map, and the LED lamp plate is used for providing a uniform and sufficient illumination environment; an external connector connected to the base and used for connecting external devices; a transparent filling layer used for providing internal mechanical support; and a lightproof packaging layer wrapped outside and used for isolating external light and serving as an interface directly contacting the ground. The prosthetic foot toe component has a unique structure, can realize force sensing and ground environment detection based on the principle of the optical flow method, the preparation method is simple, and the prosthetic foot toe component has important value in the fields of ankle-foot prosthesis design and application.

Description

Technical Field

[0001] This invention belongs to the field of bionic prostheses, specifically relating to a prosthetic toe component with ground environment detection capabilities and its manufacturing method. Background Technology

[0002] Currently, the development of ankle-foot prostheses mainly focuses on the prosthesis's impact on the user's gait and energy consumption. Optimization is achieved by altering parameters such as stiffness, flexibility, ankle joint damping, effective prosthesis length, and minimum toe gap, aiming to provide greater flexibility and drive force while ensuring safety and stability. However, the design of the toe components has not been adequately considered. For example, most ankle-foot prostheses on the market design the forefoot, midfoot, and hindfoot as a rigid, integrated structure, without addressing the design and manufacturing of independently functional toe components.

[0003] As an important part of the foot, the toes play a crucial role in walking. Studies have found that during the push-off phase of walking, the toes, along with the first and second metatarsals, share 64% of the total load on the forefoot, and the toe components account for three-quarters of the ground contact time in the gait support phase. In maintaining balance, the toes significantly influence directional control in subjects. Furthermore, the toes are also the medium of direct contact between the human musculoskeletal system and the ground; their physical interaction with the ground serves as force input to the musculoskeletal system, constantly affecting posture and balance control. Tactile sensation in the toes can convey the magnitude and direction of minute strains produced by the skin, playing a vital role in maintaining balance and preventing falls. Research indicates that older adults, due to decreased tactile sensitivity in the soles of their feet, need to increase pressure on the toe components to enhance proprioceptive sensation, thereby improving their balance.

[0004] In summary, the toes play an important biomechanical role in the ankle-foot system, and therefore, the introduction of functional toe components in the design of ankle-foot prostheses has significant clinical value.

[0005] Therefore, this invention proposes a prosthetic toe component with ground environment detection capability and its manufacturing method to meet the force (touch) sensing and ground environment detection requirements of functional toe components in prostheses. Summary of the Invention

[0006] This invention is made to solve the above-mentioned problems, and its purpose is to provide a prosthetic toe component with ground environment detection capability and a method for manufacturing the same.

[0007] This invention provides a prosthetic toe component with ground environment detection capabilities, comprising: a bottom tactile sensing layer, corresponding to the bottom area of ​​the toe, including a transparent elastomer containing microparticles, used to convert external forces into spatial displacement of the microparticles, reflecting mechanical information; a camera module, corresponding to the internal area of ​​the toe and located above the bottom tactile sensing layer, including a base and a miniature RGB camera and an LED light panel mounted on the base, the miniature RGB camera used to capture the optical flow characteristics of the microparticles when the bottom tactile sensing layer is subjected to force and convert it into an optical flow map, the LED light panel used to provide a uniform and sufficient lighting environment; an external component, connected to the base, used for connecting the prosthetic toe component to external devices; a transparent filling layer, filling and fixing between the bottom tactile sensing layer and the camera module, used to provide mechanical support inside the prosthetic toe component; and an opaque encapsulation layer, wrapping around the bottom tactile sensing layer, the camera module, the external component, and the transparent filling layer, forming a human toe-like shape, used to isolate external light, and serving as the interface for direct contact between the prosthetic toe component and the ground.

[0008] The prosthetic toe component with ground environment detection capability provided by the present invention may also have the following feature: the transparent elastomer is a transparent silicone with hardness properties that conform to the soft tissue at the bottom of the human toe.

[0009] The prosthetic toe component with ground environment detection capability provided by the present invention may also have the following feature: the material of the transparent filling layer is high-hardness transparent silicone.

[0010] The prosthetic toe component with ground environment detection capability provided by the present invention may also have the following feature: the material of the opaque encapsulation layer is opaque silicone.

[0011] The prosthetic toe component with ground environment detection capability provided by the present invention may also have the following feature: the base is provided with a connector for connecting an external component, which is a screw.

[0012] The prosthetic toe component with ground environment detection capability provided by this invention may also have the following feature: the prosthetic toe component uses a neural network algorithm to learn through the neural network, taking the optical flow map obtained by the miniature RGB camera as input and the ground material as output, to establish a mapping relationship between the optical flow map and the ground environment, thereby realizing the function of intelligently identifying the ground environment.

[0013] The present invention also provides a method for preparing the above-mentioned prosthetic toe component, characterized by the following steps: S1, combining the anatomical features of human toes and the features of the prosthetic toe component, designing and preparing a half-layer mold for preparing the bottom tactile sensing layer and an integral mold for preparing the entire prosthetic toe component; S2, selecting a suitable miniature RGB camera and LED light board, and mounting them on a base to form a shooting module; S3, laying the bottom tactile sensing layer in the half-layer mold; S4, first installing the external component on the base of the shooting module, and positioning them together in the cavity of the half-layer mold through an external positioning plate, then pouring a transparent filling layer into the cavity and curing it to form a solid shape, so that the bottom tactile sensing layer and the shooting module are integrated; S5, removing the solidified structure from the half-layer mold in step S4, fixing it in the integral mold using a fixing plate, pouring the outermost opaque encapsulation layer and curing it to form a solid shape, thus obtaining the encapsulated prosthetic toe component.

[0014] The method for preparing the prosthetic toe component provided by the present invention may also include the following steps: S6, installing the prosthetic toe component onto a force measuring platform, selecting several typical ground materials for testing, and obtaining optical flow maps corresponding to different ground materials; S7, using neural network learning, taking the optical flow map as input and the ground material as output, establishing a mapping relationship between the optical flow map and the ground environment, and realizing the function of intelligent recognition of the ground environment by the prosthetic toe component.

[0015] The role and effect of invention

[0016] The prosthetic toe component with ground environment detection capability and its manufacturing method according to the present invention are characterized by the following: the prosthetic toe component includes a bottom tactile sensing layer, a camera module, an external component, a transparent filling layer, and an opaque encapsulation layer. Based on the principle of optical flow, when the bottom of the prosthetic toe component is subjected to force, a miniature RGB camera can capture the optical flow characteristics of particles in the bottom tactile sensing layer and convert the stress at the bottom of the prosthetic toe component into an optical flow map, thus representing the corresponding ground environment and enabling intelligent identification of the ground environment. Therefore, this prosthetic toe component has a unique structure, can realize force (tactile) sensing and ground environment detection, and has a simple manufacturing method, which has significant value in the design and application of ankle and foot prostheses. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a prosthetic toe component with ground environment detection capability in an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of the shooting module and the external component in an embodiment of the present invention, wherein (a) is a side view of the shooting module and the external component, and (b) is a bottom view of the shooting module and the external component;

[0019] Figure 3 This is a schematic diagram of the displacement state of the particles under stress in an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram illustrating the principle of the prosthetic toe component sensing the ground environment in an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram illustrating the operation of laying the bottom tactile sensing layer in an embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram illustrating the operation of the shooting module and external components in the positioning of the semi-layer mold in an embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram illustrating the operation of casting a transparent filler layer in an embodiment of the present invention;

[0024] Figure 8 This is a schematic diagram of the operation of casting the opaque encapsulation layer in an embodiment of the present invention;

[0025] Figure 9 This is a schematic diagram illustrating the application of the prosthetic toe component in an ankle-foot prosthesis according to an embodiment of the present invention;

[0026] Figure 10 This is a schematic diagram illustrating how the prosthetic toe component of the prosthesis is directly worn by a partially amputated patient in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Half-layer mold; 2. Overall mold; 3. External positioning plate; 100. Prosthetic toe component; 10. Bottom tactile sensing layer; 20. Imaging module; 21. Base; 211. Connector; 22. Miniature RGB camera; 23. LED light board; 30. External component; 40. Transparent filling layer; 50. Opaque encapsulation layer. Detailed Implementation

[0029] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following embodiments are described in detail with reference to the accompanying drawings.

[0030] Example

[0031] Figure 1 This is a structural diagram of a prosthetic toe component 100 equipped with ground environment detection capabilities.

[0032] like Figure 1 As shown, this embodiment provides a prosthetic toe component 100 with ground environment detection capability, including a bottom tactile sensing layer 10, a shooting module 20, an external component 30, a transparent filling layer 40, and an opaque encapsulation layer 50.

[0033] The bottom tactile sensing layer 10 is positioned corresponding to the bottom area of ​​the toes. It is composed of a transparent elastomer containing microparticles and is used to convert external forces into spatial displacement of the microparticles, thus reflecting mechanical information. In this embodiment, the transparent elastomer is a silicone material with hardness properties that conform to the soft tissue of the bottom of the human toes. Multiple layers can be provided, with microparticles evenly distributed in each layer of transparent elastomer.

[0034] Figure 2 This is a structural schematic diagram of the shooting module 20.

[0035] The imaging module 20 is positioned above the bottom tactile sensing layer 10 and corresponds to the inner area of ​​the toes. It is used to capture the changes in particles caused by force on the bottom tactile sensing layer 10 and save them as optical information.

[0036] like Figure 2 As shown, the imaging module 20 includes a base 21 and a miniature RGB camera 22 and an LED light panel 23 mounted on the base 21. The base 21 secures the miniature RGB camera 22 and the LED light panel 23, preventing their positions from changing when the prosthetic toe component 100 is subjected to force. The miniature RGB camera 22 captures the optical flow characteristics of particles in the bottom tactile sensing layer 10 when subjected to force, and converts the stress (magnitude and direction) at the bottom of the prosthetic toe component 100 into an optical flow map, ensuring high tactile sensitivity of the prosthetic toe component 100. The LED light panel 23 provides a uniform and sufficient lighting environment for the miniature RGB camera 22.

[0037] The external connector 30 is used to connect external devices to the toe component 100 of the prosthesis. In this embodiment, the external connector 30 is a screw, and the base 21 of the imaging module 20 is provided with a connector 211 for connecting the screw. The connector 211 connects the base 21 and the screw, so that the whole structure forms a rigid structure.

[0038] like Figure 1 As shown, the transparent filler layer 40 is filled and fixed between the bottom tactile sensing layer 10 and the imaging module 20, providing mechanical support inside the prosthetic toe component 100. In this embodiment, the transparent filler layer 40 is made of high-hardness transparent silicone.

[0039] An opaque encapsulation layer 50 surrounds the bottom tactile sensing layer 10, the imaging module 20, the external connector 30, and the transparent filling layer 40, forming a shape resembling a human toe. Only a portion of the base 21 of the imaging module 20 and a portion of the external connector 30 are exposed. The opaque encapsulation layer 50 serves to block external light and also acts as the interface between the prosthetic toe component 100 and the ground. In this embodiment, the opaque encapsulation layer 50 is made of opaque silicone.

[0040] The following describes the principle of how the toe component 100 of this prosthetic limb detects the ground environment.

[0041] The prosthetic toe component 100 is designed based on the principle of acquiring optical flow through a camera. By interacting with the ground through the bottom of the prosthetic toe component 100, the stress field of the skin at the bottom of the prosthetic toe component 100 is characterized by a microparticle optical flow field, including the magnitude and direction of the stress in contact with the ground. The stress field is converted into an optical flow map to represent the corresponding ground environment.

[0042] The optical flow field is a 2D vector field that can be used to display the movement of a point from the first frame to the second frame, such as... Figure 3 The diagram illustrates the displacement state of a particle under stress, with arrows representing optical flow vectors. Optical flow algorithms can extract meaningful features by processing the displacement of each pixel in an image frame by frame. For example, the sparse optical flow algorithm, given a pixel I(x, y) in the image at time t, aims to find the displacement of that pixel in each direction at the next time step, expressed by the formula:

[0043] I(x+u,y+v,t+1)=I(x,y,t) (1)

[0044] Perform a Taylor expansion on the right-hand side of equation (1):

[0045]

[0046] In equation (2), and The gradient of the image in the δx and δy directions at the current moment. Let δx and δy represent the gradient in the time direction, i.e., the difference between the next frame and the current frame, and let δx and δy be the pixel motion to be solved. Thus, we obtain equation (3):

[0047] I x δ x +I y δ y =-I t (3)

[0048] Therefore, based on the spatial consistency assumption, the equation can be solved to obtain the displacement of the pixel in each direction.

[0049] Furthermore, such as Figure 4The schematic diagram of the principle of the prosthetic toe component 100 sensing the ground environment shows that when the prosthetic toe component 100 interacts with different ground surfaces (such as tile, cement, carpet, etc.), it generates optical flow maps of particles with different changing trends. By using a neural network algorithm, the optical flow map is used as input and the ground material is used as output to establish a mapping relationship between the optical flow map and the interaction with different ground environments. This enables the prosthetic toe component 100 to sense and identify the ground environment.

[0050] The following describes the preparation method of the toe component 100 of this prosthesis.

[0051] Taking the fabrication of a prosthetic toe component 100 with dimensions of approximately 45mm in length, 30mm in width, and 30mm in height as an example, the specific process and steps are as follows:

[0052] S1. Combining the anatomical features of human toes and the features of the prosthetic toe component 100, design and prepare a prosthetic toe component mold of appropriate shape and size. The prosthetic toe component mold includes a half-layer mold 1 for preparing the bottom tactile sensing layer 10 and an integral mold 2 for preparing the entire prosthetic toe component 100.

[0053] The design and manufacturing process can be further refined as follows: first, design the shape and size of the prosthetic toe component 100 based on the CT anatomical diagram of the human foot toe, and then prepare the prosthetic toe component mold based on the designed prosthetic toe component 100.

[0054] S2. Select a suitable miniature RGB camera 22 and LED light board 23, and mount the miniature RGB camera 22 and LED light board 23 on the base 21 to form a shooting module 20.

[0055] The size of the miniature RGB camera 22 is selected based on the cross-sectional height of the designed prosthetic toe component 100. The structure, resolution, viewing angle, frame rate, focal length, and other parameters of the miniature RGB camera 22 are determined according to the shape and size of the designed prosthetic toe component 100, ensuring that it can capture a sufficient area of ​​optical flow. In this embodiment, the dimensions of the miniature RGB camera 22 are 8.5mm in length, 8.5mm in width, and 8mm in height, with a lens viewing angle of 180 degrees.

[0056] The LED light panel 23 must ensure that the internal lighting of the prosthetic toe component 100 is sufficient, uniform, and unobstructed.

[0057] S3, such as Figure 5 As shown in the schematic diagram of laying the bottom tactile sensing layer 10, three layers of transparent silicone with a thickness of 1.5mm and a hardness performance that conforms to the soft tissue of the bottom of the human toe are laid in the half-layer mold 1. Microparticles are evenly sprinkled on each layer and cured to form a 4.5mm thick bottom tactile sensing layer 10.

[0058] S4, such as Figure 6 The diagram illustrates the operation of the imaging module 20 and the external connector 30 in the positioning of the semi-layer mold 1. First, the screw, i.e., the external connector 30, is installed on the base 21 of the imaging module 20, and together they are positioned in the cavity of the semi-layer mold 1 with the bottom tactile sensing layer 10 laid on it by the external positioning plate 3. Then, as shown in the diagram... Figure 7 As shown in the schematic diagram of the operation of casting the transparent filling layer 40, a transparent silicone with a relatively high hardness (reference hardness: 45A) is cast into the cavity of the half-layer mold 1 and cured to form a single unit, so that the bottom tactile sensing layer 10 and the shooting module 20 are connected together.

[0059] S5, such as Figure 8 As shown in the schematic diagram of the operation of casting the opaque encapsulation layer 50, the structure that has been cured in step S4 is taken out from the half-layer mold 1 and fixed in the whole mold 2 using a fixing plate. The outermost 1.5mm thick opaque silicone is cast and cured to form the final encapsulated prosthetic toe component 100.

[0060] S6. Install the packaged prosthetic toe component 100 onto the force measuring platform, select several typical floor materials (such as tile, cement floor, carpet, etc.) for testing, and obtain the optical flow diagrams corresponding to different floor materials.

[0061] S7. Using neural network learning, with optical flow maps as input and ground materials as output, a mapping relationship between optical flow maps and the interaction between the ground environment is established to achieve the function of intelligent identification of the ground environment.

[0062] This embodiment also provides two specific application methods for the prosthetic toe component 100.

[0063] Figure 9 This is a schematic diagram of the application of the prosthetic toe component 100 in an ankle-foot prosthesis.

[0064] like Figure 9 As shown, the prosthetic toe component 100 can be installed in the ankle-foot prosthesis via the external connector 30. It adopts a non-invasive feedback mode and physically interacts with the ground through the prosthetic toe component 100 to realize the function of recognizing the ground environment.

[0065] Figure 10 This is a schematic diagram of the prosthetic toe component 100 worn directly by a partially amputated patient.

[0066] like Figure 10 As shown, the prosthetic toe component 100 can also be worn directly by patients with partial foot amputations. It adopts an invasive feedback mode to help patients rebuild their force perception ability at the bottom of their toes.

[0067] The role and effect of the embodiments

[0068] According to the prosthetic toe component with ground environment detection capability and its manufacturing method involved in this embodiment, since the prosthetic toe component includes a bottom tactile sensing layer, a camera module, an external component, a transparent filling layer, and an opaque encapsulation layer, based on the principle of optical flow, when the bottom of the prosthetic toe component is subjected to force, the miniature RGB camera can capture the optical flow characteristics of the particles in the bottom tactile sensing layer and convert the stress at the bottom of the prosthetic toe component into an optical flow map, thus representing the corresponding ground environment and enabling intelligent identification of the ground environment. Therefore, this prosthetic toe component has a unique structure, can realize force (tactile) sensing and ground environment detection, and has a simple manufacturing method, which has important value in the design and application of ankle and foot prostheses.

[0069] Among them, the transparent elastomer of the bottom tactile sensing layer is preferably made of transparent silicone with hardness properties that conform to the soft tissue of the bottom of the human toe; the material of the transparent filling layer is preferably made of high-hardness transparent silicone; and the material of the opaque encapsulation layer is preferably made of opaque silicone.

[0070] External components can be selected according to actual needs, and can be parts with connecting functions such as screws.

[0071] The intelligent ground environment recognition function of the prosthetic toe component is achieved through neural network learning. It takes the optical flow map obtained from a miniature RGB camera as input and the ground material as output, and establishes a mapping relationship between the optical flow map and the ground environment.

[0072] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A prosthetic toe component with ground environment detection capability, characterized in that, include: The bottom tactile sensing layer, corresponding to the bottom area of ​​the toes, includes a transparent elastomer containing microparticles, which is used to convert external forces into spatial displacement of the microparticles, thus reflecting mechanical information; The camera module, located corresponding to the inner area of ​​the toes and above the bottom tactile sensing layer, includes a base and a miniature RGB camera and LED light panel mounted on the base. The miniature RGB camera is used to capture the optical flow characteristics of the particles in the bottom tactile sensing layer when subjected to force, and convert them into an optical flow map. The LED light panel is used to provide a uniform and sufficient lighting environment; An external connector, attached to the base, is used to connect the prosthetic toe component to external devices; A transparent filling layer is filled and fixed between the bottom tactile sensing layer and the imaging module to provide mechanical support inside the prosthetic toe component; as well as An opaque encapsulation layer is wrapped around the bottom tactile sensing layer, the imaging module, the external component, and the transparent filling layer, forming a shape resembling a human toe. This layer is used to block external light and serves as the interface between the prosthetic toe component and the ground. The prosthetic toe component utilizes a neural network algorithm. Through neural network learning, it takes the optical flow map obtained from the miniature RGB camera as input and the ground material as output to establish a mapping relationship between the optical flow map and the ground environment, thereby achieving the function of intelligently recognizing the ground environment.

2. The prosthetic toe component with ground environment detection capability according to claim 1, characterized in that: in, The transparent elastomer is a transparent silicone material whose hardness conforms to the soft tissue at the bottom of the human toes.

3. The prosthetic toe component with ground environment detection capability according to claim 1, characterized in that: in, The transparent filler layer is made of high-hardness transparent silicone.

4. The prosthetic toe component with ground environment detection capability according to claim 1, characterized in that: in, The material of the opaque encapsulation layer is opaque silicone.

5. The prosthetic toe component with ground environment detection capability according to claim 1, characterized in that: in, The base is provided with a connector for connecting the external component, and the external component is a screw.

6. A method for manufacturing a prosthetic toe component with ground environment detection capability as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Combining the anatomical features of human toes and the features of prosthetic toe components, design and fabricate a half-layer mold for fabricating the bottom tactile sensing layer and an integral mold for fabricating the entire prosthetic toe component. S2. Select a suitable miniature RGB camera and LED light board, and mount them on the base to form a shooting module; S3. Lay a bottom tactile sensing layer in the semi-layer mold; S4. First, install the external component on the base of the shooting module and position it together in the cavity of the half-layer mold through the external positioning plate. Then, pour a transparent filling layer into the cavity and cure it to form a whole, so that the bottom tactile sensing layer and the shooting module are connected as one. S5. Take the solidified structure from the half-layer mold in step S4 and fix it in the whole mold using a fixing plate. Pour the outermost opaque encapsulation layer and solidify it to obtain the encapsulated prosthetic toe component. S6. Install the prosthetic toe component onto the force measuring platform, select several typical ground materials for testing, and obtain the optical flow diagrams corresponding to different ground materials; S7. Using neural network learning, with optical flow maps as input and ground materials as output, a mapping relationship between optical flow maps and ground environment is established to realize the function of intelligent recognition of ground environment for prosthetic toe components.

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