Biomechanical sensor and application
By designing a biomechanical sensor built into Kirigami structure using PVDF sensing units, the problem that existing sensors cannot accurately detect the biomechanical effects of rotator cuffs in different directions is solved, and biomechanical detection of different positions and directions is achieved. It is suitable for Real-time monitoring and evaluation of postoperative rehabilitation process.
Patent Information
- Application Number
- CN202411371032.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-02-07
AI Technical Summary
Existing biomechanical sensors cannot accurately detect the biomechanical effects in different directions at the rotator cuff position, resulting in large errors in the detection structure and cannot be used for postoperative rehabilitation.
A biomechanical sensor is designed, using a layered flexible base layer, functional layer and flexible packaging layer. The functional layer includes multiple PVDF sensing units arranged in an array. The PVDF sensing units are constructed into a Kirigami structure and passed through the axis. The shoulders are directly contacted to collect action signals.
This sensor can realize biomechanical detection in different positions and directions, convert tiny strains on the muscle surface into electrical signals, has good tensile fatigue, and can circulate stably. It is suitable for the full detection of rotator cuff healing after surgery in patients. and assessment.
Smart Images
Figure CN119385501A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of sensor design, and in particular to a biomechanical sensor and its application. Background Art
[0002] Real-time monitoring of rotator cuff biomechanics after surgery could allow for the development of personalized rehabilitation plans for patients. However, there is currently no method to continuously monitor the rehabilitation process during the rehabilitation process.
[0003] In response to the above problems, technicians in the relevant field have tried to paste flexible biosensors that can collect biological signals on the rotator cuff to solve the above problems. However, due to the different tendon arrangements at different positions of the human rotator cuff, the directions of the forces acting on the shoulder joint are also different, and the existing flexible biosensors usually have a predetermined detection direction, so they cannot collect biomechanical effects at different positions and directions well, which leads to large errors in the detection structure and cannot be used for postoperative rehabilitation.
[0004] Therefore, in view of the above shortcomings, the present invention is proposed. Summary of the invention
[0005] The purpose of the present invention is to provide a biomechanical sensor and application to solve the problem in the prior art that the biomechanical sensor cannot accurately detect biological forces in different directions at the rotator cuff position.
[0006] A first aspect of the present invention provides a biomechanical sensor comprising a stacked flexible substrate layer, a functional layer and a flexible packaging layer, wherein the functional layer comprises a plurality of PVDF sensing units arranged in an array, the PVDF sensing units being constructed as a Kirigami structure, and the plurality of PVDF sensing units being connected in parallel and collecting motion signals by direct contact with a shaft shoulder.
[0007] The biomechanical sensor provided by the present invention may also have the following additional technical features:
[0008] In a specific embodiment of the present invention, the PVDF sensing unit includes a PVDF film constructed as a Kirigami structure, a flexible circuit board, a top electrode and a bottom electrode, wherein the top electrode and the bottom electrode are respectively arranged on two opposite sides of the PVDF film, and the flexible circuit board is arranged on the other side of the top electrode or the bottom electrode relative to the PVDF film, and is respectively connected to the top electrode and the bottom electrode.
[0009] In a specific embodiment of the present invention, the thickness of the PVDF film is 11-50 μm.
[0010] In a specific embodiment of the present invention, the piezoelectric effect of the PVDF film is utilized. When the user's shoulder joint moves, the tendon will stretch or contract accordingly, so that the biosensor in contact with the rotator cuff tendon will produce tension changes. The biosensor converts the different tension changes into corresponding electrical signals, and uses the electrical signals to perform rotator cuff biomechanics identification.
[0011] In a specific embodiment of the present invention, the Kirigami structure includes a boomerang structure, a dumbbell structure, a blade structure or a serpentine structure, and the array is in the shape of a closed curve, or the array is in the shape of a flower, or the array is in the shape of a windmill.
[0012] In a specific embodiment of the present invention, the flexible encapsulation layer and the flexible substrate layer are made of PDMS material, Ecoflex material or a mixture of PDMS material and Ecoflex material.
[0013] In a specific embodiment of the present invention, the flexible encapsulation layer material and the flexible base layer include PDMS Sylgard 184 and Ecoflex 00-30 in a weight ratio of 1:1-25.
[0014] In a specific embodiment of the present invention, the size of the biomechanical sensor is (2-5) cm×(1-3) cm, preferably 3.5 cm×1.5 cm.
[0015] In a specific embodiment of the present invention, the modulus of the biomechanical sensor is 200 KPa-7 MPa.
[0016] The second aspect of the present invention also provides an application of any of the above-mentioned biomechanical sensors in electronic skin, new medical implants, wearable devices and bionic robots.
[0017] The biomechanical sensor provided by the present invention constructs the PVDF sensing unit into a Kirigami structure, so that the PVDF sensing unit can have a set direction deformation and detect the biological strain in the corresponding direction. By forming the PVDF sensing unit into an array and cooperating with a flexible packaging layer with a skin-like tissue modulus, the biomechanical sensor can realize biomechanical detection in different positions and directions, and convert the tiny strain on the muscle surface into an electrical signal. At the same time, it has good tensile fatigue resistance and can perform stable cyclic detection. Based on the above settings, the biomechanical sensor can be used for real-time detection of tendon biomechanics in the patient's body, and can reflect the actual stress condition of the rotator cuff during the patient's shoulder joint activity. Then, the rotator cuff healing condition can be fully detected and evaluated after the patient's surgery, and the postoperative rehabilitation process can be evaluated by dynamically collecting the signals generated by the shoulder joint activity, and then a personalized rehabilitation plan can be formulated. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0019] Figure 1 is a schematic cross-sectional structure diagram of a biomechanical sensor according to an embodiment of the present invention;
[0020] Figure 2 An explosion diagram of a biomechanical sensor according to an embodiment of the present invention;
[0021] Figure 3 A front view of a functional layer in one embodiment;
[0022] Figure 4 is a front view of a functional layer in another embodiment;
[0023] Figure 5 It is a front view of a Kirigami structure in one embodiment.
[0024] Description of reference numerals:
[0025] 100-biomechanical sensor;
[0026] 10-flexible substrate layer, 20-PVDF film, 30-bottom electrode, 40-top electrode, 50-flexible encapsulation layer. DETAILED DESCRIPTION
[0027] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.
[0028] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.
[0029] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.
[0030] For ease of description, spatial relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, then the elements described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.
[0031] Reference Figure 1-5In a first aspect, the present invention provides a biomechanical sensor 100, comprising a stacked flexible substrate layer 10, a functional layer and a flexible packaging layer 50, wherein the functional layer comprises a plurality of PVDF sensing units arranged in an array, wherein the PVDF sensing units are constructed as a Kirigami structure, and the plurality of PVDF sensing units are connected in parallel and collect motion signals by directly contacting the shaft shoulder.
[0032] Kirigami is a design and manufacturing framework that allows the design of multifunctional materials and structures at different scales. By carefully designed slit cutting of geometric shapes, the desired mechanical properties (precise shape deformation, adjustable tensile expansion, super-stretchability, buckling, and multi-stability) can be imparted to the originally inflexible sheets. In addition, the Kirigami structure also provides a versatile platform for embedding different electronic and responsive components, opening up a way to build metamaterials and sensors.
[0033] In this embodiment, the PVDF sensing unit is constructed into a Kirigami structure, so that the PVDF sensing unit can deform in a set direction and detect the biological strain in the corresponding direction. The PVDF sensing unit is formed into an array and matched with a flexible packaging layer 50 with a skin-like tissue modulus, so that the biomechanical sensor 100 can realize biomechanical detection in different positions and directions, and convert the tiny strain on the muscle surface into electrical signals, and has good tensile fatigue resistance and can perform stable cyclic detection.
[0034] In one embodiment, the PVDF sensing unit includes a PVDF film 20 constructed as a Kirigami structure, a flexible circuit board, a top electrode 40 and a bottom electrode 30, wherein the top electrode 40 and the bottom electrode 30 are respectively arranged on two opposite sides of the PVDF film 20, and the flexible circuit board is arranged on the other side of the top electrode 40 or the bottom electrode 30 relative to the PVDF film 20, and is connected to the top electrode 40 and the bottom electrode 30 respectively.
[0035] In one embodiment, the thickness of the PVDF film 20 is 11-50 μm. Specifically, the thickness of the PVDF film 20 can be any value between 11-50 μm, such as 20 μm, 25 μm, 35 μm, 40 μm, 45 μm, etc. In this embodiment, the thickness of the PVDF film 20 is 30 μm.
[0036] Furthermore, the thickness of the electrode is 30-70 nm, the thickness of the top encapsulation layer and the bottom encapsulation layer is 20-50 um, and the total thickness is 50-150 um.
[0037] In one embodiment, the piezoelectric effect of the PVDF film 20 is utilized. When the user's shoulder joint moves, the tendon will stretch or contract accordingly, so that the biosensor in contact with the rotator cuff tendon will produce tension changes. The biosensor converts the different tension changes into corresponding electrical signals, and uses the electrical signals to perform rotator cuff biomechanics identification.
[0038] In one embodiment, the Kirigami structure includes a boomerang structure, a dumbbell structure, a blade structure or a serpentine structure, and the array is in the shape of a closed curve, or the array is in the shape of a flower, or the array is in the shape of a windmill.
[0039] In one embodiment, the flexible encapsulation layer 50 and the flexible base layer 10 are made of PDMS material, Ecoflex material or a mixture of PDMS material and Ecoflex material.
[0040] The PDMS Sylgard 184 and Ecoflex 00-30 can be common commercial products in the industry. For example, the A agent / B agent in the formula of the PDMS Sylgard 184 is mixed in a weight ratio of (5-25):1 in its commercial guidance. For example, the PDMS mixing ratio can be set to 10:1, 15:1, 5:1, 20:1, 25:1. Ecoflex 00-30 is made by mixing the A agent and the B agent in its brand formula in a ratio of 1:(0.5-1.5) (specifically 1:1 in the following case).
[0041] This embodiment has good biocompatibility by using the above materials. It can not only directly contact with skin tissue, but also detect human health for a long time. At the same time, the cured PDMS material and Ecoflex material have good tensile properties and good resilience, and can withstand large deformation. In addition, the above materials also have good adhesion, so that the flexible encapsulation layer 50 and the flexible substrate can not only seamlessly fit with the hollow part of the functional layer, but also can well protect the functional layer, better prevent the functional layer material from contacting the external environment (including tissues in the body), thereby preventing the generation of leakage current and improving the sensitivity of the biomechanical sensor 100. At the same time, it can also improve the adhesion between the flexible substrate layer 10, the flexible encapsulation layer 50 and the functional layer, so that there is no need to use 705 silicone rubber as an adhesive between the layers of the biomechanical sensor 100, thereby effectively suppressing the out-of-plane buckling during the measurement process.
[0042] In one embodiment, the flexible encapsulation layer 50 material and the flexible base layer 10 include PDMS Sylgard 184 and Ecoflex 00-30 in a weight ratio of 1:1-25 and 1:(0.5-1.5). This ensures the robustness and reusability of the biomechanical sensor 100 in terms of its ability to adhere to human skin.
[0043] In one embodiment, the size of the biomechanical sensor 100 is (2-5) cm×(1-3) cm, preferably 3.5 cm×1.5 cm. Specifically, the size of the biomechanical sensor 100 can be determined according to the human tissue to be attached, which will not be described in detail here.
[0044] In one embodiment, the modulus of the biomechanical sensor 100 is 200 KPa-7 MPa. Specifically, the modulus of the flexible encapsulation layer 50 is 1 MPa, and the modulus can be 200 KPa-7 MPa by selecting different ratios.
[0045] The microstructure of the skin is composed of peaks and troughs. If the modulus of the biomechanical sensor 100 is relatively large, it is not easy to bend, so it cannot completely fit the trough position of the skin tissue when attached. The biomechanical sensor 100 with a smaller modulus can better fit the skin surface and has better adhesion. The modulus of the biomechanical sensor 100 mainly depends on the material of the flexible packaging layer 50. By making the modulus of the flexible packaging layer 50 basically consistent with the modulus of the skin to be attached, and specifically in the range of 200KPa-7MPa, the biomechanical sensor 100 can have good adhesion, thereby ensuring that the biomechanical sensor 100 can better play the advantages of high sensitivity and mechanical flexibility. In addition, good adhesion can also avoid the use of additional mechanical fixtures or tapes, thereby reducing the restrictions on the attachment area.
[0046] The second aspect of the present invention also provides an application of any of the above-mentioned biomechanical sensors 100 in electronic skin, new medical implants, wearable devices and bionic robots.
[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A biomechanical sensor, characterized in that: It includes a stacked flexible substrate layer, a functional layer and a flexible packaging layer, wherein the functional layer includes a plurality of PVDF sensing units arranged in an array, the PVDF sensing units are constructed as a Kirigami structure, and the plurality of PVDF sensing units are connected in parallel and collect action signals by directly contacting the shaft shoulder.
2. The biomechanical sensor according to claim 1, characterized in that The PVDF sensing unit includes a PVDF film constructed as a Kirigami structure, a flexible circuit board, a top electrode and a bottom electrode, wherein the top electrode and the bottom electrode are arranged on two opposite sides of the PVDF film, and the flexible circuit board is arranged on the other side of the top electrode or the bottom electrode relative to the PVDF film, and is connected to the top electrode and the bottom electrode respectively.
3. The biomechanical sensor according to claim 2, characterized in that: The thickness of the PVDF film is 11-50 μm.
4. The biomechanical sensor according to claim 2, characterized in that: Utilizing the piezoelectric effect of PVDF film, when the user's shoulder joint moves, the tendon will stretch or contract accordingly, so that the biosensor in contact with the rotator cuff tendon will produce tension changes. The biosensor converts the different tension changes into corresponding electrical signals, and uses the electrical signals to perform rotator cuff biomechanics identification.
5. The biomechanical sensor according to claim 1, characterized in that: The Kirigami structure includes a boomerang structure, a dumbbell structure, a blade structure or a serpentine structure, and the array is in a closed curve shape, or the array is in a flower shape, or the array is in a windmill shape.
6. The biomechanical sensor according to claim 1, characterized in that: The flexible encapsulation layer and the flexible base layer are made of PDMS material, Ecoflex material or a mixture of PDMS material and Ecoflex material.
7. The biomechanical sensor according to claim 6, characterized in that: The flexible encapsulation layer material and the flexible base layer include PDMS Sylgard 184 and Ecoflex00-30 in a weight ratio of 1:1-25.
8. The biomechanical sensor according to claim 1, characterized in that: The size of the biomechanical sensor is (2-5) cm×(1-3) cm, preferably 3.5 cm×1.5 cm.
9. The biomechanical sensor according to claim 1, characterized in that: The modulus of the biomechanical sensor is 200KPa-7MPa.
10. Application of the biomechanical sensor according to any one of claims 1 to 9 in electronic skin, new medical implants, wearable devices and bionic robots.