CN111543729A - Force-sensitive sensor, array sensor and plantar pressure detection device - Google Patents

Abstract

The invention discloses a force-sensitive sensor, an array sensor and a plantar pressure detection device, wherein the force-sensitive sensor comprises a first waterproof rubber film layer, an interdigital electrode layer, a force-sensitive sensor coating and a double-sided adhesive layer which are sequentially overlapped from top to bottom, the interdigital electrode layer consists of two electrodes which are arranged in an interdigital crossing manner at intervals, and the two electrodes of the interdigital electrode layer are respectively connected with an external circuit through a circuit; the force-sensitive sensor coating completely covers the area of the interdigital electrode layer, and the first waterproof rubber film layer covers all the area of the force-sensitive sensor coating. The force sensor has the advantages of simple structure, excellent waterproof performance, good bending resistance and long service life. The array sensor is designed according to the human engineering principle, only the key positions of the soles are distributed with points, signals of main force-applying points of the soles are collected, layout is simplified, meanwhile, detection efficiency of sole pressure is improved, and the problem that key pressure data are lost is solved.

Description

Force-sensitive sensor, array sensor and plantar pressure detection device

Technical Field

The invention relates to the technical field of force-sensitive sensors, in particular to a force-sensitive sensor, an array sensor thereof and a plantar pressure detection device.

Background

At present, with the rapid development of sleeping economy and the improvement of the attention degree of people to self health, the plantar pressure detection technology is gradually developed, the gait of a user can be monitored through pressure monitoring of different parts of the soles of the people, whether the gait has the risks of slope feet, flat feet and inward and outward turning is judged, and the gait rehabilitation training device is convenient to discover as early as possible and correct bad gait in time.

Compared with the traditional sensor applied to plantar pressure signal acquisition, the traditional sensor applied to plantar pressure signal acquisition has the disadvantages of poor bending resistance and unsatisfactory waterproofness, so that the service life of the traditional sensor is short; moreover, such sensors are thick and heavy, and experience is poor. The existing plantar pressure acquisition device based on the plantar pressure array sensor is complex in structure, excessive and unreasonable in arrangement of acquisition points, high in cost, complex in processing technology, low in fault tolerance rate and low in data value.

For example, as shown in fig. 1, the device is named as a "plantar pressure signal acquisition device" by chinese patent No. (CN 208511028U), and forms a pressure monitoring array by electrodes arranged horizontally and longitudinally and a pressure sensor sandwiched therebetween, so as to detect plantar pressure when a person walks. The technology has the disadvantages that the layout of the sole is simply densely paved, the technical difficulty is increased, the process complexity is improved, and thus, the sensors densely arranged mean lower fault tolerance rate, so that the whole device is easier to damage; secondly, the array sensor formed by the simple and dense laid without design is easy to avoid the position of a main force application point, so that the key pressure change information of the sole is missed. Therefore, the value of the sole pressure data collected by the device is low.

Therefore, the prior art has yet to be developed.

Disclosure of Invention

In view of the above technical problems, embodiments of the present invention provide a new force-sensitive sensor, a corresponding array sensor, and a plantar pressure detection device. The force-sensitive sensor is a flexible sensor, and has the advantages of simple structure, excellent waterproof performance, good bending resistance and long service life. The sensor layout of the array sensor is reasonable, the number of the sensors is greatly reduced, main force points of the sole are not omitted, and the detection efficiency of the sole pressure is improved.

In order to solve the problems, the invention provides the following technical scheme:

the invention provides a force-sensitive sensor, which comprises a first waterproof rubber film layer, an interdigital electrode layer, a force-sensitive sensor coating and a double-sided adhesive layer which are sequentially overlapped from top to bottom, wherein the interdigital electrode layer is formed by two electrodes which are arranged in an interdigital cross way at intervals, and the two electrodes of the interdigital electrode layer are respectively connected with an external circuit through a circuit; the force-sensitive sensor coating completely covers the area of the interdigital electrode layer, and the first waterproof rubber film layer covers all the area of the force-sensitive sensor coating.

Optionally, the force sensor further comprises a second waterproof rubber film layer located below the double-sided adhesive layer.

Optionally, in the force-sensitive sensor, the interdigital electrode layer is in a circular, oval or rectangular structure, and the shape of the coating of the force-sensitive sensor is consistent with the shape of the interdigital electrode layer.

The invention also provides an array sensor for detecting the pressure of the sole, which is arranged and fixed on the treading part of the sole, the array sensor consists of a plurality of force-sensitive sensors, and the force-sensitive sensors are distributed in the following three functional areas: a front sole area, a middle sole area and a rear sole area of the sole tread part; the force-sensitive sensors in the rear sole area are in odd number and are arranged in rows along the width direction; the middle sole area is provided with two strip-shaped force-sensitive sensors arranged along the length direction; the front sole area is provided with a first front sole area force-sensitive sensor covering the position corresponding to the metatarsus of the big toe and a second front sole area force-sensitive sensor at least covering the position corresponding to the metatarsus of the small toe.

Optionally, the plantar tread is an insole, a sole, or a sole of a sock.

Optionally, the force-sensitive sensors in the hind paw region include a middle force-sensitive sensor and other edge force-sensitive sensors; the middle force-sensitive sensors are positioned on the middle line, and the edge force-sensitive sensors are symmetrically distributed by taking the middle line as a symmetrical bearing.

Optionally, the middle sole area is provided with two strip-shaped inner force-sensitive sensors and two strip-shaped outer force-sensitive sensors respectively arranged along the inner side position of the middle part of the sole and the outer side position of the middle part of the sole.

Preferably, the second forefoot area force sensor is oval, the major diameter of the second forefoot area force sensor is perpendicular to the metatarsal bones of the little finger, and the second forefoot area force sensor extends to the metatarsal bones of 2-3 toes adjacent to the little finger.

The present invention also provides a plantar pressure detection device, which includes:

the array sensor is fixed on the sole, the insole or the sock bottom and used for collecting original signals of the pressure of the sole of a human body and transmitting the original signals to the signal conditioning circuit;

the signal conditioning circuit is used for amplifying and filtering an original signal of human physiological data and extracting real-time pressure signals of all test points of the sole array sensor;

and the signal processing circuit is used for calculating the output signal of the signal conditioning circuit so as to obtain the pressure magnitude of each test point and the data result of the pressure distribution of the sole.

Preferably, the plantar pressure detecting device further includes:

and the communication module transmits the data result obtained by the processing of the signal processing circuit to the display unit.

Further preferably, the plantar pressure detecting device further includes:

and the display unit is used for receiving the data result sent by the communication module and displaying the data result.

The invention also provides an intelligent shoe or an insole, wherein the sole pressure detection device or the array sensor is arranged at the bottom of the intelligent shoe or the insole.

The force-sensitive sensor provided by the embodiment of the invention has the following beneficial effects:

1. the force-sensitive sensor is a flexible sensor, has a simple structure, is endowed with excellent waterproof performance and bending resistance through only 4 layers of film structures, and greatly prolongs the service life. The force-sensitive sensor coating is a core component for converting the change of pressure into the change of resistance. The interdigital electrode layer is used as a printing electrode, the resistance value change of the force-sensitive sensor is transmitted to the structure of the back end circuit, the structure cannot damage the structure of the force-sensitive sensor, and the toughness of the whole sensor can be increased to a certain extent. The first waterproof rubber film layer is used for protecting the force-sensitive sensor from being damaged by the outside, so that the force-sensitive sensor is more resistant to bending, and the service life of the sensor is prolonged. And the whole sensor has waterproof performance due to the waterproof property of the rubber. The double-sided glue layer not only realizes the bonding between the multilayer structures of the force-sensitive sensor, but also can firmly bond the sensor and the foot treading part, thereby preventing the sensor from falling off or loosening in the use process.

2. The ingenious layout mode of the array sensor not only solves the problems of excessively complex sensor distribution points and higher process design difficulty in the prior design, but also greatly simplifies the manufacturing mode of the sensor; the device is designed according to the human engineering principle, and the signals of the main force points of the sole are collected only by arranging points at the key positions of the sole, so that the layout of the sensor is simplified, the detection efficiency of the sole pressure is improved, and the problem of missing key pressure data is solved.

Drawings

FIG. 1 is a schematic structural diagram of a plantar pressure signal acquisition device in the prior art;

FIG. 2 is an exploded perspective view of a force sensor in accordance with example 1 of the present invention;

FIG. 3 is a top view of a force sensor in accordance with embodiment 1 of the present invention;

FIG. 4 is an exploded side view of the structure of a force sensor in example 1 of the present invention;

FIG. 5 is a schematic structural view of an array sensor in example 2 of the present invention;

FIG. 6 is a flow chart of the force sensor signal conversion of the present invention;

FIG. 7 is a pressure resistance curve of the force sensor of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. The use of the designated orientations or positional relationships in the present specification are based on the orientations or positional relationships illustrated in the drawings and are intended only to facilitate the description of the present invention and to simplify the description, but are not intended to indicate or imply that the designated devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Example 1

As shown in fig. 2 to 4, this embodiment provides a novel force sensor, which includes a first waterproof rubber thin film layer 23, an interdigital electrode layer 22, a force sensor coating 21, and a double-sided adhesive layer 24, which are sequentially overlapped from top to bottom, where the interdigital electrode layer 22 is formed by two electrodes arranged in an interdigital-crossing manner at intervals, and the two electrodes of the interdigital electrode layer 22 are electrically connected to an external circuit through a fixedly connected line, respectively. The first waterproof rubber film layer 23 covers all areas of the force sensor coating 21.

The interdigital electrode layer 22 is a printed electrode, and is composed of positive and negative electrodes disposed at intervals in an interdigitated manner in the same printing plane. The interdigital electrode layer 22 is made of a light, thin, flexible and high-toughness metal material through a printing process. Because the printing electrode is softer and has large contact area with the force-sensitive resistance coating, the force-sensitive resistance coating cannot be damaged.

In this embodiment, the interdigital electrode layer 22 connects the force-sensitive sensor with an external back-end circuit through a line, so that the signal of the force-sensitive sensor can be transmitted to the back-end circuit. When the installation space is large, as shown in fig. 2, the circuit adopts a metal foil 25 with certain elasticity and bending resistance, and the printed electrode can realize the electric connection between the force-sensitive sensor and the rear-end circuit through the metal foil arranged at the tail part; when applied to a dense limited space, such as an array application, the wires are metal printed wires, as shown in fig. 5, which not only greatly saves wiring space, but also ensures the flexibility of the force sensor.

Specifically, in the force-sensitive sensor, the interdigital electrode layer 22 can be in a circular, elliptical or rectangular structure; the shape of the force-sensitive sensor coating 21 is identical to the shape of the interdigital electrode layer 22, and the area of the force-sensitive sensor coating 21 is slightly larger than the area of the interdigital electrode layer 22, so as to ensure that the force-sensitive sensor coating 21 can completely cover the area of the interdigital electrode layer 22.

For solving the waterproof problem of sensor, this application adopts first waterproof rubber film layer 23 to carry out surface covering to the sensor, carries out water repellent. Specifically, the area of the first waterproof rubber film layer 23 is larger than that of the force sensor coating layer 21 to achieve its covering and waterproof function. The above design has the following advantages: firstly, the waterproof rubber material has acoustic impedance which is closer to that of a human body, so that pressure change of feet of the human body can be completely transmitted to the force-sensitive sensor coating, and the accuracy of signal acquisition is improved; and secondly, the waterproof rubber film has excellent hydrophobic property and sealing property, so that the waterproof rubber film can be used as an outer layer to better isolate an external water source, prevent the external water source from leaking into the sensor and endow the sensor with a good waterproof effect. In addition, the rubber film layer has good ductility and elasticity, and can greatly reduce the pressure abrasion and bending of the force-sensitive sensor coating 21 in the external environment, thereby greatly prolonging the service life of the sensor.

The force sensor of the embodiment is fixed between internal multi-layer structures through the double-faced adhesive layer 24, and the whole sensor structure is fixedly adhered to the bottom of the sole or the insole. The sensor is effectively prevented from falling or loosening by the arrangement, and the problems that the pressure acquisition result is not accurate due to the loosening phenomenon of the sensor and the sensor is damaged due to the falling phenomenon of the sensor are further avoided. The area of the two-sided adhesive layer 24 should be greater than the area of the upper force sensor coating 21.

As shown in fig. 2, in application, after the interdigital electrode layer 22 and the force sensor coating 21 are fixedly connected to the preset position of the sole or the insole through the double-sided adhesive layer 24, the surface of the structures is covered with a first waterproof rubber film layer 23, and the force sensor is assembled and fixed through the fixed connection of the first waterproof rubber film layer 23 and the preset position. The sensor is ingenious in design that the force-sensitive sensor is endowed with excellent waterproof performance, bending resistance and the like through the arrangement of only 4 layers of thin film structures.

In other embodiments, in order to provide the force sensor with a separate structure for quick removal, recovery and replacement of the mounting portion, the force sensor further comprises a second waterproof rubber film layer under the double-sided adhesive layer 24. The edges of the first waterproof rubber film layer 23 and the second waterproof rubber film layer are hermetically connected, such as bonded. The force-sensitive sensor arranged in this way is an independent waterproof unit which is assembled, and is convenient to store, install and recover quickly.

The force-sensitive sensor is subjected to a pressure resistance value curve test to obtain an experimental result shown in fig. 7, so that the force-sensitive sensor is high in sensitivity, high in measurement precision, large in measuring range and high in application value.

Example 2

In order to overcome various problems caused by unreasonable layout of sensors of the conventional plantar pressure signal acquisition device, the present embodiment provides an array sensor for detecting plantar pressure as shown in fig. 5, which is arranged on a plantar treading portion, wherein the array sensor is formed by arranging a plurality of force-sensitive sensors in embodiment 1 on the same horizontal plane in a certain rule, and the force-sensitive sensors are distributed in the following three functional areas: a forefoot area 3, a middle foot area 4 and a rear foot area 5 of the foot sole tread part.

The first waterproof rubber film layer 23 and the second waterproof rubber film layer of the array sensor are integrally coated with all the force-sensitive sensors from top to bottom respectively, so that the integral packaging arrangement is realized, and the convenience in processing and mounting of the array sensor is improved. In other embodiments, the array sensor can be divided into 3 sensor sub-arrays packaged independently according to the three functional areas of the forefoot area 3, the middle sole area 4 and the rear sole area 5.

Specifically, the foot bottom treading part is an insole, a sole or a sock bottom. Array sensor accessible bonding mode fixed connection is trampled on portion in the sole, perhaps tramples portion through detachable connected mode and sole and is connected, detachable connected mode can be for magic subsides bonding or buckle connection etc..

In the array sensors, the force-sensitive sensors in the rear sole area 6 are odd number and are arranged in rows along the width direction; wherein, the middle force-sensitive sensors 51 are positioned on the central line, and the edge force-sensitive sensors 52 are symmetrically distributed by taking the central line as a symmetrical bearing. In this embodiment, the number of force sensors in the rear sole region 6 is 5, which spans the entire heel region, and the measurement range is wide, and the sensors in this region are arranged in a circular shape.

The odd number of sensors are arranged in the heel area to collect pressure data of the heel part of a human body, and the sensors at the part have two main functions: the first is the mark which can be used for judging that a certain sole contacts the ground when the human body walks. In the normal walking process, the heel should contact the ground first, then the middle part of the sole and the front sole area are arranged in sequence, and whether the walking posture is abnormal or not can be judged according to the above. And secondly, the method can be used as a standard for assisting in judging the risk of heel pronation and supination. Five sensors at the heel part are sequentially arranged from left to right and span the whole heel, so that when the heel is turned inside and outside, the risk of turning inside and outside the heel can be judged in an auxiliary manner according to the uneven stress of the left sensor and the right sensor.

For the middle sole area 4, two strip-shaped inner force-sensitive sensors 41 and outer force-sensitive sensors 42 are arranged along the inner side position of the middle part of the sole and along the outer side position of the middle part of the sole. The two sensors are used for acquiring the pressure data change of the main stress area of the middle sole area. The sensor at this location also has two functions: firstly, the mark of the middle part of the sole contacting the ground can be judged in the walking process, and the change data of the pressure in the middle part of the sole can be collected. And secondly, the method can be used as a mark for assisting in judging the risk of the flat feet.

The following three differences exist mainly due to the normal foot and the flat foot:

first, there is a significant difference in the percentage of the area of each area of the sole of the foot between the normal foot and the flat foot to the entire palm. For the pressure on one side (inner side) of the arch of the middle sole area, the normal foot is obviously smaller than the flat foot, and the pressure on the outer side of the middle sole area is larger than the pressure on the same position of the flat foot. Because of the different contact areas, the normal foot has a greater contact pressure on the heel and the forefoot than on the flat foot.

Secondly, when the sole is grounded, the ratio of the supporting time of each area of the sole of the normal foot to the supporting time of each area of the sole of the flat foot to the whole supporting time of the sole of the foot is also obviously different. Compared with the flat foot, the proportion of the supporting time of the sole of the foot before the normal foot to the total supporting time of the sole of the foot is obviously smaller.

Thirdly, when walking normally, compared with the flat feet, the impulse of the normal feet in the middle sole area has a significant difference. As in the arch portion, the momentum of a normal foot is less than that of a flat foot.

Therefore, the two strip-shaped inner force-sensitive sensors 41 and outer force-sensitive sensors 42 can collect the pressure change and the pressure bearing time change of the main supporting parts at the inner side and the outer side of the middle sole area, and are used for assisting in judging the risk of the flat feet of the monitored person by combining the pressure change of the rest parts of the soles.

Preferably, the projections of medial force sensitive sensor 41 and lateral force sensitive sensor 42 on the midline completely overlap. The two sensors 41 thus arranged have corresponding detection positions, which facilitates data analysis. The strip-shaped arrangement of the force-sensitive sensor in the area effectively enlarges the pressure signal acquisition efficiency and reduces the processing difficulty.

For the front sole area 3, a first front sole area force-sensitive sensor 31 is arranged at the position corresponding to the metatarsal bone of the thumb, and a second front sole area force-sensitive sensor 32 is arranged at the position corresponding to the metatarsal bone of the little thumb and is used for collecting the pressure change of the main pressure-bearing part of the front sole area. The two sensors are designed to be oval, and the effective area of signal acquisition is enlarged on the premise of saving materials.

The second forefoot area force sensor 32 is oval, the major axis of the second forefoot area force sensor is perpendicular to the metatarsal of the little finger, and the second forefoot area force sensor 32 extends to the metatarsal of 2-3 toes adjacent to the little finger. This is arranged to cover a greater range of force points.

Because the front sole of the foot of the lameness crowd lands on the ground in the walking process, when data of a sole supporting phase (the supporting time of each part of the sole accounts for the supporting time of the whole sole) are analyzed, the supporting phase of the front sole of the lameness crowd can be obviously found to be larger than that of the front sole of the normal crowd. Therefore, the two sensors are arranged in the front sole area, and the limping risk can be effectively monitored in an auxiliary mode. More importantly, the two sensor points, namely the left sensor point, the right sensor point and the left sensor point, just cover the main force-applying point of the front sole, and can be combined with other area analysis to detect more other gait characteristics besides the lameness.

Example 3

The present embodiment provides a plantar pressure detection device, which includes:

the array sensor according to embodiment 2 is fixed on a sole, an insole or a sock bottom, and is used for collecting a human sole pressure original signal and transmitting the original signal to a signal conditioning circuit.

And the signal conditioning circuit is used for amplifying and filtering the original signal of the human physiological data and extracting the real-time pressure signal of each test point of the sole array sensor.

And the signal processing circuit is used for calculating the output signal of the signal conditioning circuit so as to obtain the pressure magnitude of each test point and the data result of the pressure distribution of the sole.

In other embodiments, based on this, the sole pressure detecting device further includes:

and the wireless communication module transmits the data result obtained by the processing of the signal processing circuit to the display unit.

And the display unit is used for receiving the data result sent by the wireless communication module and displaying the data result. The display unit comprises a mobile phone client, a computer client, a server and the like.

The invention also provides an intelligent shoe or an insole, wherein the sole pressure detection device or the array sensor is arranged at the bottom of the intelligent shoe or the insole.

It should be understood that the technical solutions and concepts of the present invention may be equally replaced or changed by those skilled in the art, and all such changes or substitutions should fall within the protection scope of the appended claims.

Claims (10)

1. A force-sensitive sensor is characterized by comprising a first waterproof rubber film layer (23), an interdigital electrode layer (22), a force-sensitive sensor coating (21) and a double-sided adhesive layer (24) which are sequentially overlapped from top to bottom, wherein the interdigital electrode layer (22) is formed by two printed electrodes which are arranged in a finger-shaped crossed manner at intervals, and the two electrodes of the interdigital electrode layer (22) are respectively connected with an external circuit through a circuit; the force-sensitive sensor coating (21) completely covers the area of the interdigital electrode layer (22), and the first waterproof rubber film layer (23) covers all the area of the force-sensitive sensor coating (21).

2. The force sensor of claim 1, further comprising a second waterproof rubber film layer under the double-sided adhesive layer (24), the edges of the two waterproof rubber film layers being sealingly connected.

3. Force sensor according to claim 1, characterized in that the interdigital electrode layer (22) presents a circular, oval or rectangular configuration, the shape of the force sensor coating (21) coinciding with the shape of the interdigital electrode layer (22).

4. An array sensor for detecting sole pressure, which is arranged on a sole treading part, characterized in that the array sensor is composed of a plurality of force-sensitive sensors according to claim 1, and the force-sensitive sensors are distributed in the following three functional areas: a front sole area (3), a middle sole area (4) and a rear sole area (5) of the foot sole treading part;

the force-sensitive sensors in the rear sole area (5) are odd and arranged in rows along the width direction; the middle sole area (4) is provided with two strip-shaped force-sensitive sensors arranged along the length direction; the forefoot area (3) is provided with a first forefoot area force-sensitive sensor (31) covering the part corresponding to the metatarsus of the big toe and a second forefoot area force-sensitive sensor (32) covering at least the part corresponding to the metatarsus of the small toe.

5. The array sensor of claim 4, wherein the foot bottom tread is an insole, a sole, or a sole of a sock.

6. An array sensor according to claim 4, characterized in that the force-sensitive sensors of the hindfoot sole region (5) comprise a central force-sensitive sensor (51) and further edge force-sensitive sensors (52); the middle force-sensitive sensors (51) are positioned on the central line, and the other edge force-sensitive sensors (52) are symmetrically distributed by taking the central line as a symmetrical bearing.

7. Array sensor according to claim 6, characterized by a middle sole area (4) with two strips of inner (41) and outer (42) force-sensitive sensors arranged along the medial and lateral middle of the sole, respectively.

8. The array transducer according to claim 7, wherein the second forefoot area force sensor (32) is elliptically shaped with a major diameter perpendicular to the metatarsals of the little finger, the second forefoot area force sensor (32) extending to the metatarsal region of 2-3 toes adjacent to the little finger.

9. A plantar pressure detection device, characterized by comprising:

the array sensor of claim 2, fixed on the sole, insole or sock sole, for collecting the original signal of the human plantar pressure and transmitting the original signal to the signal conditioning circuit;

the signal conditioning circuit is used for amplifying and filtering an original signal of human physiological data and extracting real-time pressure signals of all test points of the sole array sensor;

and the signal processing circuit is used for calculating the output signal of the signal conditioning circuit so as to obtain the pressure magnitude of each test point and the data result of the pressure distribution of the sole.

10. An intelligent shoe or insole, characterized in that the bottom is provided with a plantar pressure detection device as claimed in claim 9 or an array sensor as claimed in any one of claims 4 to 8.

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