Pressure sensor, wearable device and system for gait information acquisition

Abstract

The utility model discloses a pressure sensor used for gait information acquisition, a wearable device and a system, the pressure sensor comprises a first flexible base layer and a second flexible base layer, the first flexible base layer and the second flexible base layer are respectively provided with a plurality of sensing areas electrically connected by conductive circuit layers, the sensing areas correspond to gait pressure points, and the conductive circuit layers are electrically connected with the sensing areas. The sensing area on the first flexible base layer is electrically connected to the conductive terminal through the first conductive circuit layer, the sensing area on the second flexible base layer is electrically connected to the conductive terminal through the second conductive circuit layer, and the Young modulus of the first flexible base layer, the Young modulus of the first conductive circuit layer, the Young modulus of the second conductive circuit layer and the Young modulus of the sensing area are sequentially reduced. The first flexible base layer and the second flexible base layer are each provided with a plurality of through holes located in the outer side of the induction area in a one-to-one correspondence mode. According to the utility model, the pressure can still be accurately measured when the sensing area is subjected to multidirectional stress of the first flexible base layer and the second flexible base layer, and the measurement precision of the pressure sensor is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of smart wearables, in particular to a pressure sensor, a wearable device and a system for collecting gait information. Background Art

[0002] Gait refers to the movements and postures of a person when walking, which is closely related to the health conditions of the human bones, muscles and nervous system. Since a person moves on different road conditions, the responses of various parts of the body are different, resulting in different pressures and pressure distributions on different parts of the sole. Therefore, in the fields of scientific research and medical treatment, gait analysis of human movement is particularly important, and it is often necessary to accurately know the force between the human sole and the ground, the contact condition between the sole and the ground, and the pressure distribution on the sole when a person walks or moves. In recent years, the development of smart wearable products has been rapid, and the number of wearable products for collecting gait information has also been increasing day by day. For example, many domestic and foreign research institutions and companies are also developing smart shoes and smart insole products, etc., which are integrated with pressure sensors, and some gait information of the human body can be obtained through the pressure sensors.

[0003] Among the pressure sensors for measuring gait information by pressure, according to different pressure-sensitive elements, the pressure sensors are divided into types such as strain type, piezoresistive type, capacitive type, and resistance strain gauge type. However, most of the pressure sensors for collecting sole pressure have some limitations in application. For example, the patent document with the publication number CN205107687U discloses a "pressure sensor, wearable device and system for collecting gait information", which can improve the service life of the pressure sensor, has good stretchability, flexibility and antistatic property during use, and can adapt to more occasions. However, this solution has some problems: it uses a stretchable flexible substrate, which has a certain Young's modulus. If the tensile force is too large, the flexible substrate will be damaged. Therefore, during long-term use, the multi-directional stress and torsion of human walking are likely to reduce the service life and measurement accuracy of the pressure sensor. Summary of the Utility Model

[0004] To solve the above technical problems existing in the prior art, the utility model provides a pressure sensor, a wearable device and a system for collecting gait information, which can collect the pressure changes of different parts of the sole in gait information, improve the accuracy of pressure measurement, prevent the multi-directional pressure and torsion from affecting the service life of the pressure sensor, and improve its measurement accuracy. The specific technical solutions of the utility model are as follows.

[0005] The present utility model first provides a pressure sensor for gait information acquisition, which includes relatively arranged first and second flexible substrates made of flexible materials. The first and second flexible substrates are respectively provided with a plurality of sensing areas corresponding to gait pressure points. The sensing areas on the first flexible substrate are electrically connected to conductive terminals through a first conductive circuit layer, and the sensing areas on the second flexible substrate are electrically connected to conductive terminals through a second conductive circuit layer. The Young's moduli of the first flexible substrate, the second flexible substrate, the first conductive circuit layer, the second conductive circuit layer, and the sensing areas decrease in sequence. The first flexible substrate and the second flexible substrate are both provided with a corresponding plurality of through holes located outside the sensing areas.

[0006] As a further technical solution, the first flexible substrate and the second flexible substrate are made of high-temperature resistant polyester film or polydimethylsiloxane material.

[0007] As a further technical solution, the first conductive circuit layer, the second conductive circuit layer, and the sensing areas are all made of flexible polymer loaded with nano conductive materials.

[0008] As a further technical solution, the through holes are arranged in an annular array on the outer periphery of the sensing areas.

[0009] As a further technical solution, the through holes extend in multiple rows in the horizontal direction of the first flexible substrate and the second flexible substrate, and are evenly arranged on the outer periphery of the sensing areas.

[0010] As a further technical solution, the ratio of the Young's moduli of the first flexible substrate, the second flexible substrate, the first conductive circuit layer, the second conductive circuit layer, and the sensing areas is 6 - 9:3 - 5:1 - 2.

[0011] As a further technical solution, the conductive terminal is provided with an electronic module assembly and a measuring resistor.

[0012] The present utility model further includes a wearable device for gait information acquisition, which includes a device body, including the above-mentioned pressure sensor, a micro control module electrically connected to the pressure sensor, and a power supply module. The micro control module and the power supply module are arranged on the non-force-bearing side of the device body. The micro control module includes an analog-to-digital conversion unit and a Bluetooth communication unit electrically connected to the pressure sensor, and the Bluetooth communication unit is connected to an external acquisition terminal.

[0013] As a further technical solution, a gyroscope module is provided at the position of the device body located in the metatarsal arch area of the sole.

[0014] The present utility model further includes a system for collecting gait information, which includes a collection terminal and the above wearable device. The collection terminal and the wearable device are connected through a Bluetooth network. The wearable device collects human gait information and sends it to the collection terminal, and the collection terminal displays the human gait information.

[0015] The beneficial effects of the present utility model are as follows: for the pressure sensor of the present utility model, the Young's moduli of the first flexible base layer, the second flexible base layer, the conductive circuit layer, and the sensing area decrease in sequence, which can improve the tensile resistance of the first conductive circuit layer, the second conductive circuit layer, and the sensing area, enabling the sensing area to accurately measure the pressure received under the state of multi-directional stress from the first flexible base layer and the second flexible base layer, and improving the service life and measurement accuracy of the pressure sensor; the first flexible base layer and the second flexible base layer are provided with multiple independent sensing areas, and each sensing area corresponds to a force application point, which can measure the force conditions of various parts during walking, accurately determine the changes in the sole pressure, and improve the accuracy of gait information collection. Brief Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the pressure sensor for gait information collection of the present utility model;

[0017] Figure 2 is a schematic sectional view of the pressure sensor for gait information collection of the present utility model;

[0018] Figure 3 is a schematic module diagram of the wearable device for gait information collection of the present utility model;

[0019] Figure 4 is a schematic circuit diagram of measuring the resistance of the sensing area for gait information collection of the present utility model;

[0020] In the figure: 1 - the first flexible base layer; 2 - the second flexible base layer; 3 - the sensing area; 4 - the through hole; 5a - the first conductive circuit layer; 5b - the second conductive circuit layer; 6 - the conductive terminal; 8 - the device body; 9 - the micro control module; 901 - the analog-to-digital conversion unit; 902 - the Bluetooth communication unit; 10 - the power module; 11 - the gyroscope module. Detailed Description of the Preferred Embodiments

[0021] In order to make the objectives, technical solutions, and advantages of the present utility model clearer, the present utility model 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 only used to explain the present utility model and are not used to limit the present utility model.

[0022] In the description of the present utility model, it should be understood that the terms "longitudinal", "lateral", "upper", and "lower" are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features.

[0023] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "coupled" should be understood in a broad sense. For example, it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0024] As Figure 1 shown, a pressure sensor for gait information acquisition according to the present utility model includes relatively arranged first flexible substrates 1 and second flexible substrates 2 made of flexible materials. The first flexible substrate 1 and the second flexible substrate 2 are adhesively connected to each other as a whole and can be integrated into an insole or a sole. Figure 1 The figure shows a schematic diagram after the first flexible substrate 1 and the second flexible substrate 2 are peeled off and relatively flipped half a turn along a vertical line in the figure. The shapes of the first flexible substrate 1 and the second flexible substrate 2 are only used to describe that the pressure sensor of the present utility model has a two-layer structure, and their shapes can be set according to specific application scenarios and the stress range. It can be the shape of an insole as shown in the figure, or can be set to other shapes according to scientific research requirements, and no special limitation is made here.

[0025] The flexible materials used for the first flexible substrate 1 and the second flexible substrate 2 are made of high-temperature resistant polyester film or flexible polymer materials. Polyester film is one of the commonly used barrier composite film substrates, and has good stretchability, softness and antistatic properties during use, which can improve the service life of the pressure sensor.

[0026] As Figure 1As shown, on the opposite sides of the first flexible base layer 1 and the second flexible base layer 2, there are respectively provided a first conductive circuit layer 5a and a second conductive circuit layer 5b. After the first flexible base layer 1 and the second flexible base layer 2 are adhesively bonded to each other, the first conductive circuit layer 5a and the second conductive circuit layer 5b do not come into contact. The first conductive circuit layer 5a and the second conductive circuit layer 5b are made of the same material. The first conductive circuit layer 5a and the second conductive circuit layer 5b are respectively electrically connected to a plurality of sensing regions 3. That is, both the first flexible base layer 1 and the second flexible base layer 2 have a plurality of sensing regions 3. The plurality of sensing regions 3 are all printed on the first flexible base layer 1 and the second flexible base layer 2, and the sensing regions 3 are arranged in a one-to-one correspondence and correspond to the gait pressure points.

[0027] The first conductive circuit layer 5a, the second conductive circuit layer 5b, and the sensing region 3 are all made of a flexible polymer loaded with a nano-conductive material. Preferably, a nano-silver paste material is loaded on a stretchable flexible polymer. The following Young's modulus refers to the Young's modulus of the flexible polymer. The flexible polymer can be made of polydimethylsiloxane or polyimide material. Of course, there is no limitation on this, and other flexible polymer materials loaded with nano-silver paste material can also be used. After the nano-silver paste material is loaded on the flexible polymer, it is printed on the opposite sides of the first flexible base layer 1 and the second flexible base layer 2 to form the first conductive circuit layer 5a and the second conductive circuit layer 5b, and the conductivity is not affected when compressed and stretched.

[0028] As Figure 1 shown, in some preferred embodiments, when the two opposite sensing regions 3 of the first flexible base layer 1 and the second flexible base layer 2 are under pressure, their resistance values will change, forming a Wheatstone bridge with the following measured resistance, and then measuring the pressure received by the two sensing regions 3. As Figure 3 shown in the circuit schematic diagram, the measured resistance includes R1, R2, and R3, which are fixed resistors, and Rx is the resistance of the sensing region 3 to be measured. When the upper and lower two sensing regions 3 are in contact under pressure, they are connected to form a resistance to be measured with two lead-out ends. The resistor R1 and the resistor R2 are connected in series, and the resistor R3 and the resistor Rx to be measured are connected in series. At the midpoints of R1 and R2, and at the midpoints of R3 and Rx, an electronic module component in the conductive terminal 6 is connected. The electronic module component is used to measure the voltages at both ends of the Wheatstone bridge respectively. By measuring the change in this voltage, the resistance value of the sensing region 3 and the pressure received can be obtained. The sensing region 3 on the first flexible base layer 1 is electrically connected to the conductive terminal 6 through the first conductive circuit layer 5a, and the sensing region 3 on the second flexible base layer 2 is electrically connected to the conductive terminal 6 through the second conductive circuit layer 5b.

[0029] Specifically, when two oppositely arranged sensing regions 3 are subjected to pressure, their internal structures will undergo minute deformations, resulting in hindrance to the flow of electrons within the material, thereby causing changes in the resistance value. The circuit between the two oppositely arranged layers of sensing regions 3 is conducted, and the output resistance changes with different pressures and forms a bridge circuit with the measuring resistance. When the sensing region 3 is subjected to pressure, its resistance value changes, leading to changes in the ratios of the resistances in the bridge circuit, and further resulting in changes in the output voltage. By measuring such changes in the output voltage, the pressure received by the sensing region 3 can be obtained. The first conductive circuit layer 5a of the first flexible base layer 1 and the second conductive circuit layer 5b of the second flexible base layer 2 are respectively electrically connected to the conductive terminals 6 provided with measuring resistances. The conductive terminals 6 contain electronic module components and integrate a power module and a micro-control module in the prior art. The measuring resistance provided by the conductive terminals 6 is a fixed resistance of about 3K - 4K in series. When an external force acts on the sensing region 3, the resistance value of the sensing region 3 changes proportionally with the change of the external force. By monitoring the change of the resistance value, the magnitude of the pressure can be judged, and the magnitude of the pressure is converted into an electrical signal through the circuit and output to an external micro-control system. Thus, the pressure value of the sensing region 3 is reflected. When the pressure is zero, the resistance value is the largest, and the greater the pressure, the smaller the resistance value, thereby reflecting the pressure distribution between the two sensing regions 3.

[0030] In some preferred embodiments, the first flexible base layer 1 and the second flexible base layer 2 have the same Young's modulus, and the first conductive circuit layer 5a and the second conductive circuit layer 5b have the same Young's modulus, which is different from that of the sensing region 3. Taking the first flexible base layer 1 as an example, the Young's moduli of the first flexible base layer 1, the first conductive circuit layer 5a, and the sensing region 3 increase or decrease in sequence. When the same tensile force and pressure are applied to the first flexible base layer 1, the first conductive circuit layer 5a, and the sensing region 3 with different Young's moduli, the deformation amounts of the three are different, which can prevent material deformation and damage caused by excessive tensile force. Preferably, the Young's moduli of the first flexible base layer 1, the first conductive circuit layer 5a, and the sensing region 3 decrease in sequence. For example, the numerical range of the Young's modulus ratios of the first flexible base layer 1, the first conductive circuit layer 5a, and the sensing region 3 is 6 - 9:3 - 5:1 - 2.

[0031] In some preferred embodiments, the first flexible base layer 1 and the second flexible base layer 2 are both provided with a corresponding number of through holes 4. The through holes 4 are located outside the sensing region 3. Adding holes in these two non-sensor regions of the first flexible base layer 1 and the second flexible base layer 2 can increase the deformation amount of this region, relatively reduce the deformation amount of the sensing region 3, and reduce the possible deformation damage that the sensing region 3 may suffer. Preferably, the through holes 4 are arranged in an annular array on the outer periphery of the sensing region 3, which can increase the deformation amounts of the first flexible base layer 1 and the second flexible base layer 2 and reduce the influence of this deformation amount on the sensing region 3.

[0032] The through holes 4 extend in multiple rows in the horizontal direction of the first flexible base layer 1 and the second flexible base layer 2, and are evenly arranged on the outer periphery of the sensing area 3. At this time, whether the through holes 4 extend in the thickness direction of the first flexible base layer 1 and the second flexible base layer 2 or in the horizontal direction of the first flexible base layer 1 and the second flexible base layer 2, the flexibility of the first flexible base layer 1 and the second flexible base layer 2 can be increased, further reducing the deformation influence on the sensing area 3 and improving the service life of the sensing area 3. When the sensing area 3 is compressed and deformed, its elastic deformation is not likely to cause a large tensile force on the first conductive circuit layer 5a and the first flexible base layer 1, and when the first conductive circuit layer 5a and the first flexible base layer 1 undergo elastic deformation, it is not likely to damage the sensing area 3 either. The Young's moduli of the first flexible base layer 1 and the second flexible base layer 2 are the same. This is because the lower the Young's modulus, the relatively larger the deformation, the smaller the stiffness, and the easier the material is to deform; the higher the Young's modulus, the relatively smaller the deformation of the material due to the Young's modulus, the larger the stiffness, and the more difficult the material is to deform. Therefore, when the first flexible base layer 1 and the second flexible base layer 2 are deformed to a certain extent, the first conductive circuit layer 5a and the sensing area 3 still have a great tensile resistance. By adopting this different Young's modulus ratio, the tensile resistance of the first conductive circuit layer 5a and the sensing area 3 can be improved, enabling the first conductive circuit layer 5a and the sensing area 3 to maintain material stability under the state of multi-directional stress from the first flexible base layer 1 and the second flexible base layer 2, still being able to accurately measure the applied pressure, and improving the service life of the pressure sensor.

[0033] The present utility model further includes a wearable device for gait information collection, including a device body 8. The device body 8 can be an intelligent shoe or other wearable products in other shapes. The device body 8 includes the above-mentioned pressure sensor, a micro control module 9 electrically connected to the pressure sensor, and a power supply module 10. The power supply module 10 is electrically connected to the pressure sensor, the micro control module 9, and a gyroscope module 11 respectively. The micro control module 9 and the power supply module 10 are arranged on the non-loaded side of the device body 8. The micro control module 9 includes an analog-to-digital conversion unit 901 electrically connected to the pressure sensor and a Bluetooth communication unit 902. The Bluetooth communication unit 902 is connected to an external collection terminal. A gyroscope module 11 is provided at the position of the device body 8 located in the metatarsal arch area of the sole of the foot. The gyroscope module 11 uses a MEMS gyroscope, which is not affected by the pressure during walking and can detect the angular velocity and angular acceleration of the gait, providing further gait information for scientific research.

[0034] In use, the gyroscope module 11 transmits the angular velocity and angular acceleration of the device body 8 to an external acquisition terminal. The pressure sensor transmits the collected pressure signal to the analog-to-digital conversion unit 901. The analog-to-digital conversion unit 901 filters and amplifies the pressure signal and outputs a digital pressure signal to the Bluetooth communication unit 902. The Bluetooth communication unit 902 sends the digital pressure signal to the external acquisition terminal, and the external acquisition terminal analyzes and processes the pressure signal in the extracted gait information.

[0035] The present utility model further includes a system for collecting gait information, comprising an acquisition terminal and the above wearable device. The acquisition terminal and the wearable device are connected through a Bluetooth network. The wearable device collects human gait information and sends it to the acquisition terminal, and the acquisition terminal displays the human gait information.

[0036] The preferred specific embodiments and examples of the present utility model are described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes or equivalent substitutions can be made without departing from the concept of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present utility model.

Claims

1. A pressure sensor for gait information acquisition, comprising a first flexible base layer (1) and a second flexible base layer (2) which are oppositely arranged and made of flexible materials. A plurality of induction areas (3) are respectively arranged on the first flexible base layer (1) and the second flexible base layer (2), and the induction areas (3) correspond to gait pressure points. It is characterized in that: The induction area (3) on the first flexible base layer (1) is electrically connected to the conductive terminal (6) through the first conductive circuit layer (5a). The induction area (3) on the second flexible base layer (2) is electrically connected to the conductive terminal (6) through the second conductive circuit layer (5b). When two opposite induction areas (3) of the first flexible base layer (1) and the second flexible base layer (2) are in pressure contact, they are connected to form a resistance to be measured with two lead-out ends for the upper and lower induction areas (3). The Young's moduli of the first flexible base layer (1), the second flexible base layer (2), the first conductive circuit layer (5a), the second conductive circuit layer (5b), and the induction area (3) decrease in sequence. The first flexible base layer (1) and the second flexible base layer (2) are each provided with a corresponding number of through holes (4) located outside the induction area (3).

2. The pressure sensor for gait information acquisition according to claim 1, wherein: The first flexible base layer (1) and the second flexible base layer (2) are made of high-temperature resistant polyester film or flexible polymer material.

3. The pressure sensor for gait information acquisition according to claim 1, wherein: The first conductive circuit layer (5a), the second conductive circuit layer (5b), and the induction area (3) are all made of flexible polymer loaded with nano conductive material.

4. The pressure sensor for gait information acquisition according to claim 1, wherein: The through holes (4) are arranged in a circular array on the outer periphery of the induction area (3).

5. The pressure sensor for gait information acquisition according to claim 4, characterized in that: The through holes (4) extend in multiple rows in the horizontal direction of the first flexible base layer (1) and the second flexible base layer (2), and are evenly arranged on the outer periphery of the induction area (3).

6. The pressure sensor for gait information acquisition according to claim 1, characterized in that: The ratio of the Young's moduli of the first flexible base layer (1), the second flexible base layer (2), the first conductive circuit layer (5a), the second conductive circuit layer (5b), and the induction area (3) is 6 - 9:3 - 5:1 - 2.

7. The pressure sensor for gait information acquisition according to claim 1, characterized in that: The conductive terminal (6) is provided with an electronic module assembly and a measuring resistor.

8. A wearable device for collecting gait information, comprising a device body (8), characterized in that: It includes the pressure sensor according to any one of claims 1 to 7, a micro control module (9) and a power supply module (10) electrically connected to the pressure sensor. The micro control module (9) and the power supply module (10) are arranged on the unloaded side of the device body (8). The micro control module (9) includes an analog-to-digital conversion unit (901) and a Bluetooth communication unit (902) electrically connected to the pressure sensor. The Bluetooth communication unit (902) is connected to an external acquisition terminal.

9. The wearable device for gait information acquisition according to claim 8, wherein: A gyroscope module (11) is provided at the position of the device body (8) located in the metatarsal arch area of the sole.

10. A system for collecting gait information, characterized in that: It includes an acquisition terminal and a wearable device according to any one of claims 8 and 9. The acquisition terminal and the wearable device are connected through a Bluetooth network. The wearable device acquires human gait information and sends it to the acquisition terminal, and the acquisition terminal displays the human gait information.

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