Plantar pressure sensing device and system

Abstract

The present application provides a plantar pressure sensing device and system, which belongs to the field of medical device technology. The device includes: an insole body, including an ion-type flexible pressure sensor array, wherein the driving end of each row of ion-type flexible pressure sensors in the ion-type flexible pressure sensor array is configured to input an excitation voltage; a signal processing module, connected to the ion-type flexible pressure sensor array, for converting the sensing capacitance signal generated by the ion-type flexible pressure sensor array under the action of the excitation voltage into a detection voltage signal, and obtaining the plantar pressure value based on the detection voltage signal; an inertial sensing unit, configured in the insole body or the signal processing module, for collecting the gait space information of the object under test, and the signal processing module is configured to automatically adjust the amplitude of the excitation voltage according to the gait space information to match the sensing accuracy requirements of the plantar pressure under different motion states of the object under test. The present application can meet the demand for high-precision pressure distribution measurement of the sole.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a plantar pressure sensing device and system. Background Art

[0002] Foot and ankle injuries are very common in daily life, and most injuries occur during activities. As the main weight-bearing area of ​​the human body, the foot and ankle not only bear the weight of the whole body when standing, but also bear a significantly increased load during dynamic activities such as walking, running and jumping. The elderly and obese people are particularly prone to foot and ankle injuries because of their relatively weak resilience and load-bearing capacity, coupled with the additional weight.

[0003] Real-time monitoring of plantar pressure signals is essential for evaluating exercise effects, preventing foot diseases, and assisting rehabilitation training. For patients with foot and ankle injuries, reasonable control of plantar weight during rehabilitation is the key to preventing secondary injuries. However, traditional plantar pressure monitoring devices are mostly large devices that are not convenient to carry and use daily. For this reason, the prior art proposes to set a pressure monitoring area on the insole to achieve real-time monitoring of plantar pressure.

[0004] Although the design of this smart insole improves portability and practicality, it still has limitations: it cannot fully capture the plantar pressure distribution of the entire foot, making it difficult to fully analyze the changing pattern of plantar pressure during exercise. Summary of the invention

[0005] The purpose of the present application is to provide a plantar pressure sensing device and system to solve the above problems.

[0006] To achieve the above objectives, in a first aspect, the present application proposes a plantar pressure sensing device, the plantar pressure sensing device comprising:

[0007] The insole body comprises an array of ion-type flexible pressure sensors arranged in an array form of m rows and n columns, wherein the ion-type flexible pressure sensor array is used to detect the plantar pressure of the object under test and convert the plantar pressure into a sensing capacitance signal, wherein the driving end of each row of the ion-type flexible pressure sensors in the ion-type flexible pressure sensor array is configured to input an excitation voltage, and m and n are integers greater than or equal to 1;

[0008] A signal processing module, connected to the ion-type flexible pressure sensor array, for converting the sensing capacitance signal generated by the ion-type flexible pressure sensor array into a detection voltage signal under the action of the excitation voltage, and obtaining a plantar pressure value based on the detection voltage signal;

[0009] The inertial sensing unit is configured in the insole body or the signal processing module, and is used to collect the gait space information of the object under test. The signal processing module is configured to automatically adjust the amplitude of the excitation voltage according to the gait space information of the object under test to match the sensing accuracy requirement of the plantar pressure under different motion states of the object under test.

[0010] In some embodiments, the inertial sensing unit includes at least one accelerometer and at least one gyroscope, which are used to measure static posture information and dynamic rotation information of the object under measurement, and fuse the static posture information and dynamic rotation information to obtain gait spatial information of the object under measurement.

[0011] In some embodiments, the at least one acceleration sensor is used to measure the linear acceleration of the object under test in the three-axis directions of the spatial coordinate system to obtain static posture information of the object under test, and the at least one gyroscope is used to measure the angular velocity of the object under test in the three-axis directions of the spatial coordinate system to obtain dynamic rotation information of the object under test.

[0012] In some embodiments, the driving end of each row of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array is configured to input an excitation voltage and a reference voltage respectively according to a row selection state, and the excitation voltage includes a positive excitation voltage and a negative excitation voltage that are input alternately;

[0013] The signal processing module comprises:

[0014] At least one capacitance-to-pressure conversion circuit, each capacitance-to-pressure conversion circuit comprises an operational amplifier and a reference capacitor, wherein two ends of the reference capacitor are respectively connected to the inverting input terminal and the output terminal of the operational amplifier; a reference voltage is input to the non-inverting input terminal of the operational amplifier, and a first detection voltage and a second detection voltage corresponding to the positive excitation voltage and the negative excitation voltage are output to the output terminal of the operational amplifier; the detection end of each column of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array is configured to be respectively connected to the corresponding inverting input terminal of the operational amplifier and the reference voltage according to the column selection state;

[0015] A control unit is connected to the output end of the operational amplifier, and is used to calculate the capacitance value of the ion-type flexible pressure sensor in the target row in the ion-type flexible pressure sensor array based on the amplitudes of the positive excitation voltage and the negative excitation voltage, the first detection voltage and the second detection voltage, and the capacitance value of the reference capacitor, and convert the capacitance value of the ion-type flexible pressure sensor in the target row into a plantar pressure value.

[0016] In some embodiments, the signal processing module is configured to automatically adjust the amplitudes of the positive excitation voltage and the negative excitation voltage according to the gait space information of the measured object to match the sensing accuracy requirements for the plantar pressure under different motion states of the measured object.

[0017] In some embodiments, the signal processing module is configured to increase the amplitude of the positive excitation voltage and the negative excitation voltage based on the gait spatial information of the object under test, when it is determined that the force on the sole of the foot is within a first range in the current motion state of the object under test; and reduce the amplitude of the positive excitation voltage and the negative excitation voltage when it is determined that the force on the sole of the foot is within a second range in the current motion state of the object under test.

[0018] In some embodiments, the signal processing module is also used to transmit the plantar pressure value and the gait space information to an electronic device, wherein the plantar pressure value includes the pressure distribution in different areas of the sole of the subject when the sole of the subject contacts the ground and the ground reaction force in the vertical, front-to-back and left-to-right directions of the sole, and the gait space information includes the gait cycle, step length, stride, step width, step frequency, step speed and foot deviation angle of the subject.

[0019] In some embodiments, the driving end of each row of the electrically isolated flexible pressure sensors is configured to input the excitation voltage when the row selection state of the row is selected, and to input the reference voltage when the row selection state of the row is not selected.

[0020] In some embodiments, the detection end of each column of the electrically isolated flexible pressure sensor is configured to: connect to the inverting input end of the corresponding operational amplifier when the column selection state of the column is selected; and input the reference voltage when the column selection state of the column is not selected.

[0021] In addition, to achieve the above-mentioned purpose, in a second aspect, the present application also provides a plantar pressure sensing system, which includes the plantar pressure sensing device and the electronic device as described above, the plantar pressure sensing device and the electronic device are communicatively connected, and the electronic device is used to receive the plantar pressure value and the gait space information transmitted by the plantar pressure sensing device, and generate a plantar pressure distribution view and a gait pattern analysis report based on the plantar pressure value and the gait space information.

[0022] Compared with the prior art, the beneficial effects of this application include:

[0023] On the one hand, the plantar pressure sensing device of the present application uses an array of m rows and n columns of ion-type flexible pressure sensors to fully capture the pressure distribution of each area of ​​the sole, thereby realizing comprehensive monitoring of plantar pressure. This array design not only improves the response speed and measurement accuracy of the sensor, but also ensures that the device can carefully monitor the pressure changes of the entire foot. On the other hand, the signal processing module can convert the sensing capacitance signal generated by the sensor array into a detection voltage signal under the action of the excitation voltage, and further calculate the plantar pressure value, thereby realizing real-time data processing. In addition, the inertial sensing unit configured in the insole body or the signal processing module can collect the gait space information of the object being measured in real time. At the same time, the signal processing module can automatically adjust the amplitude of the excitation voltage through the gait space information collected by the inertial sensing unit to match the sensing accuracy requirements of the object being measured under different motion states. In summary, the plantar pressure sensing device of the present application realizes high-precision, real-time plantar pressure sensing through the coordinated work of the ion-type flexible pressure sensor array, the signal processing module and the inertial sensing unit, and can automatically adjust the sensing accuracy according to the motion state of the object being measured, ensuring that accurate data can be obtained under various motion states. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0025] Figure 1 is a structural schematic diagram of a plantar pressure sensing device according to an embodiment of the present application;

[0026] Figure 2 is a bottom view of a plantar pressure sensing device according to an embodiment of the present application;

[0027] Figure 3 is a schematic diagram of the circuit structure of a signal processing module in a plantar pressure sensing device according to an embodiment of the present application;

[0028] Figure 4 is a schematic diagram of a capacitance-voltage conversion circuit in a signal processing module according to an embodiment of the present application;

[0029] Figure 5 is a schematic diagram of connection between a plantar pressure sensing device and an electronic device in a plantar pressure sensing system according to an embodiment of the present application;

[0030] Figure 6 It is a schematic diagram of the structure of an electronic device involved in the plantar pressure sensing system according to an embodiment of the present application.

[0031] Explanation of the accompanying drawings: 100-plantar pressure sensing device; 110-insoles body; 111-ion-type flexible pressure sensor array; 120-signal processing module; 121-capacitance-pressure conversion circuit; 122-control unit; 130-buckle assembly; 140-inertial sensing unit; 900-electronic device; 901-central processing unit (CPU); 902-read-only memory (ROM); 903-random access memory (RAM); 904-bus; 905-input / output (I / O) interface; 906-input part; 907-output part; 908-storage part; 909-communication part; 910-drive; 911-removable medium. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] All terms (including technical and scientific terms) used in this application have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used here should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0034] For example, the terms "first", "second", etc. used in this application may be used in this document to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element.

[0035] For another example, the terms “include”, “comprising”, etc. used in this application indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0036] As mentioned above, the latest prior art proposes to set up a pressure monitoring area on the insole to achieve real-time monitoring of plantar pressure. Although the design of this smart insole improves portability and practicality, it still has limitations: it cannot fully capture the plantar pressure distribution of the entire foot, making it difficult to fully analyze the changing pattern of plantar pressure during exercise. The present application proposes a plantar pressure sensing device and system that can match the sensing accuracy requirements of the plantar pressure of the object under different motion states, and meet the demand for high-precision pressure distribution measurement of the sole.

[0037] Figure 1 is a structural schematic diagram of a plantar pressure sensing device 100 according to an embodiment of the present application. Figure 2 is a bottom view of a plantar pressure sensing device according to an embodiment of the present application. Figure 1 and Figure 2 As shown, the plantar pressure sensing device 100 of this embodiment includes:

[0038] The insole body 110 includes an ion-type flexible pressure sensor array 111 arranged in an array form of m rows and n columns, wherein the ion-type flexible pressure sensor array 111 is used to detect the plantar pressure of the object under test and convert the plantar pressure into a sensing capacitance signal, wherein the driving end of each row of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array 111 is configured to input an excitation voltage S1, and m and n are integers greater than or equal to 1;

[0039] The signal processing module 120 is connected to the ion-type flexible pressure sensor array 111, and is used to convert the sensing capacitance signal generated by the ion-type flexible pressure sensor array 111 into a detection voltage signal under the action of the excitation voltage S1, and obtain the plantar pressure value based on the detection voltage signal;

[0040] The inertial sensing unit 140 is configured in the insole body 110 or the signal processing module 120, and is used to collect the gait space information of the object under test. The signal processing module 120 is configured to automatically adjust the amplitude of the excitation voltage S1 according to the gait space information of the object under test to match the sensing accuracy requirement of the plantar pressure under different motion states of the object under test.

[0041] In this embodiment, the insole body 110 refers to the part that constitutes the basic structure of the insole, and is used to carry the ion-type flexible pressure sensor array 111 and other electronic components. Specifically, the insole body 110 can be made of a variety of materials, such as polyurethane (PU), ethylene-vinyl acetate copolymer (EVA) material, sponge or cloth, etc. Its main function is to provide support and comfort, and to be able to adapt to the shape of the sole of the foot, while also being able to effectively transmit the sole pressure to the ion-type flexible pressure sensor array 111.

[0042] In the present embodiment, the ion-type flexible pressure sensor array 111 is a group of integrated ion-type flexible pressure sensors. They are arranged in an array form for detecting and measuring the pressure distribution applied thereon. On the one hand, each sensor unit can detect pressure changes independently and do not interfere with each other, and can accurately obtain the pressure force of the sole of the foot and the pressure distribution in different areas. On the other hand, during the movement, the contact between the sole of the foot and the ground is not completely flat, but there is a certain curvature and angle. When facing this non-positive pressure, traditional pressure sensors may not be able to accurately capture the true sole of the foot pressure distribution due to the rigidity and fixed form of the sensor, resulting in inaccuracy of the data. These sensors in the present embodiment are flexible and bendable, and can better adapt to the curvature and changes of the sole of the foot, so as to more accurately measure the sole of the foot pressure distribution.

[0043] Specifically, the ion-type flexible pressure sensor array 111 includes an ion film dielectric layer and an electrode array layer composed of m rows and n columns of electrodes. When the sole of the subject under test steps on the insole body 110, the sole pressure of the subject under test acts on the ion-type flexible pressure sensor array 111, and the ion film dielectric layer will deform, causing the capacitance between the electrodes to change, thereby converting the sole pressure into a sensing capacitance signal. In this way, the ion-type flexible pressure sensor array 111 can monitor and measure the sole pressure distribution in real time, providing important data support for applications such as gait analysis and motion monitoring.

[0044] In some embodiments, the ion-type flexible pressure sensor array 111 is evenly spaced on the insole body in the form of an array of m rows and n columns. It can be understood that the evenly spaced sensor array can provide a more uniform pressure sensing result and reduce the error of spatial resolution.

[0045] In some embodiments, the ion-type flexible pressure sensor array 111 is arranged on the insole body 110 in an array form of m rows and n columns at non-uniform intervals. Specifically, different distribution methods can be designed according to the different force-bearing areas on the soles of the subjects to be measured. For conventional subjects to be measured, the heel area is the main support point of the human body weight, and the forefoot area is the force point during walking or running. Therefore, the ion-type flexible pressure sensor array 111 can be designed to have a greater arrangement density in the heel area and the forefoot area than in the arch area. For some subjects with low arches or flat feet, the arch area will be subject to greater pressure when walking or standing. Therefore, the ion-type flexible pressure sensor array 111 can be designed to have a greater arrangement density in the arch area than in the heel area and the forefoot area.

[0046] It is understandable that in the actual detection of plantar pressure, more emphasis may be placed on the pressure sensing accuracy of key points on the sole of the subject, and the non-uniformly spaced sensor array can provide higher detection accuracy in key areas of the sole, thereby further meeting the needs for high-precision detection of plantar pressure in different detection scenarios.

[0047] Further, the ion-type flexible pressure sensor array 111 in this embodiment includes m rows and n columns of ion-type flexible pressure sensors, which can be represented by the first row C11-C1n, the second row C21-C2n, ..., the mth row Cm1-Cmn according to the row; and can be represented by the first column C11-Cm1, the second column C12-Cm2, ..., the nth column C1n-Cmn according to the column. Each ion-type flexible pressure sensor in each row of ion-type flexible pressure sensors has a driving end and a detection end.

[0048] In one embodiment, the driving end of each row of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array 111 is configured to input an excitation voltage S1 and a reference voltage Vref respectively according to a row selection state, and the excitation voltage S1 includes an alternately input positive excitation voltage and a negative excitation voltage.

[0049] In one embodiment, the driving end of each row of the ion-type flexible pressure sensor is connected to the excitation voltage S1 when the row selection state of the row is selected, and the reference voltage Vref is input when the row selection state of the row is not selected. The excitation voltage S1 includes a positive excitation voltage and a negative excitation voltage that are alternately input, and the positive excitation voltage and the negative excitation voltage have opposite polarities. The row here refers to the row where each row of the ion-type flexible pressure sensor is currently located in the ion-type flexible pressure sensor array 111.

[0050] In one embodiment, the driving end of each row of the ion-type flexible pressure sensors can be respectively input with the excitation voltage S1 and the reference voltage Vref through the row selection switch (SW1-SWm) of each row. For example, the driving end of the ion-type flexible pressure sensors C11-C1n in the first row respectively inputs the excitation voltage S1 and the reference voltage Vref through the two paths of the row selection switch SW1; the driving end of the ion-type flexible pressure sensors C21-C2n in the second row respectively inputs the excitation voltage S1 and the reference voltage Vref through the two paths of the row selection switch SW2; and so on, the detection end of the ion-type flexible pressure sensors Cm1-Cmn in the mth row respectively inputs the excitation voltage S1 and the reference voltage Vref through the two paths of the row selection switch SWm.

[0051] In one embodiment, when the row selection state of the row is selected, the driving end of each row of the isolated flexible pressure sensors is connected to the input path of the excitation voltage S1 through the row selection switch (SW1-SWm) of each row, so that the driving end of each row of the isolated flexible pressure sensors inputs the excitation voltage S1; when the row selection state of the row is non-selected, the driving end of each row of the isolated flexible pressure sensors is connected to the input path of the reference voltage Vref through the row selection switch (SW1-SWm) of each row, so that the driving end of each row of the isolated flexible pressure sensors inputs the reference voltage Vref.

[0052] In this embodiment, the signal processing module 120 is a key component for realizing plantar pressure sensing. It is electrically connected to the ion-type flexible pressure sensor array 111 and is responsible for converting the sensing capacitance signal generated by the ion-type flexible pressure sensor array 111 into a detection voltage signal, thereby obtaining the plantar pressure value of the object being measured. Specifically, after converting the sensing capacitance signal from the ion-type flexible pressure sensor array 111 into a detection voltage signal, the signal processing module 120 obtains the sensing capacitance value of the ion-type flexible pressure sensor corresponding to the detection voltage signal based on the analog-to-digital conversion calculation of the detection voltage signal, and obtains the true pressure value of the ion-type flexible pressure sensor based on the pressure calibration function of the ion-type flexible pressure sensor.

[0053] In some embodiments, the signal processing module 120 is connected to the ion-type flexible pressure sensor array 111 through a buckle assembly 130, and the buckle assembly 130 is used for wiring, that is, connecting multiple signal lines in the sensor array to the signal processing module 120 in an orderly manner. In addition, the buckle assembly 130 can also be used to adjust the length between the signal processing module 120 and the ion-type flexible pressure sensor array 111 to adapt to different wearing needs and usage environments. The above embodiment can not only ensure the stability and reliability of signal transmission, but also improve the flexibility and versatility of the device.

[0054] In some embodiments, Figure 3 FIG. 1 is a schematic diagram of the circuit structure of the signal processing module 120 in the plantar pressure sensing device 100 according to an embodiment of the present application. Figure 3 As shown, the signal processing module 120 includes:

[0055] At least one capacitance-to-pressure conversion circuit 121, each capacitance-to-pressure conversion circuit 121 includes an operational amplifier (OA1-OAn) and a reference capacitor (Cr1-Crn), two ends of the reference capacitor (Cr1-Crn) are respectively connected to the inverting input terminal and the output terminal of the operational amplifier (OA1-OAn); the reference voltage Vref is input to the non-inverting input terminal of the operational amplifier (OA1-OAn), and the output terminal of the operational amplifier (OA1-OAn) outputs the first detection voltage and the second detection voltage corresponding to the positive excitation voltage and the negative excitation voltage, respectively; the detection end of each column of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array 111 is configured to be respectively connected to the inverting input terminal of the corresponding operational amplifier (OA1-OAn) and the reference voltage Vref according to the column selection state;

[0056] The control unit 122 is connected to the output end of the operational amplifier (OA1-OAn), and is used to calculate the capacitance value of the target row of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array 111 based on the amplitude of the positive excitation voltage and the negative excitation voltage, the first detection voltage and the second detection voltage, and the capacitance value of the reference capacitor (Cr1-Crn), and convert the capacitance value of the ion-type flexible pressure sensor in the target row into a plantar pressure value. The target row here refers to the current selected row in the m-row and n-column ion-type flexible pressure sensors. At this time, the target row is in the selected state, and the driving end of the ion-type flexible pressure sensor in the target row is alternately input with the positive excitation voltage and the negative excitation voltage.

[0057] In one embodiment, the detection end of each column of the m rows and n columns of the ion-type flexible pressure sensors is configured as follows: when the column selection state of the column is selected, the detection end is connected to the inverting input end of the corresponding operational amplifier; when the column selection state of the column is not selected, the reference voltage Vref is input. Specifically, when the row selection state of the target row is selected, that is, the driving end of the ion-type flexible pressure sensor of the target row inputs the excitation voltage S1, then the column selection state of each column is switched to selected, and the detection end of each column of the ion-type flexible pressure sensor is connected to the inverting input end of the corresponding operational amplifier. The column here refers to the column where each column of the ion-type flexible pressure sensor is currently located in the ion-type flexible pressure sensor array 111.

[0058] In one embodiment, the detection end of each column of the ion-type flexible pressure sensors in the m rows and n columns is configured to be connected to the inverting input terminal and the reference voltage Vref of the corresponding operational amplifier (OA1-OAn) through the column selection switch (SWc1-SWcn) of each column. For example, the detection end of the ion-type flexible pressure sensors C11-Cm1 in the first column is connected to the inverting input terminal and the reference voltage Vref of the operational amplifier OA1 through the two paths of the column selection switch SWc1; the detection end of the ion-type flexible pressure sensors C12-Cm2 in the second column is connected to the inverting input terminal and the reference voltage Vref of the operational amplifier OA2 through the two paths of the column selection switch SWc2; and so on, the detection end of the ion-type flexible pressure sensors C1n-Cmn in the nth column is connected to the inverting input terminal and the reference voltage Vref of the operational amplifier OAn through the two paths of the column selection switch SWcn.

[0059] In one embodiment, the detection end of each column of the m rows and n columns of the off-type flexible pressure sensors is configured as follows: when the column enable state of the column is enabled, the detection end of each column of the off-type flexible pressure sensors is connected to the input path of the inverting input terminal of the operational amplifier through the column enable switch (SWc1-SWcn) of each column, so that the detection end of each column of the off-type flexible pressure sensors is connected to the corresponding inverting input terminal of the operational amplifier; when the column enable state of the column is non-enabled, the detection end of each column of the off-type flexible pressure sensors is connected to the input path of the reference voltage Vref through the column enable switch (SWc1-SWcn) of each column, so that the reference voltage Vref is input to the detection end of each column of the off-type flexible pressure sensors.

[0060] In this embodiment, in each capacitance-to-voltage conversion circuit 121, the reference voltage Vref is input to the positive phase input terminal of the operational amplifier (OA1-OAn), and the output terminal of the operational amplifier (OA1-OAn) can output the first detection voltage and the second detection voltage corresponding to the positive excitation voltage and the negative excitation voltage, respectively. The first detection voltage and the second detection voltage can be detected by the control unit 122 connected to the output terminal of the operational amplifier (OA1-OAn), and the control unit 122 can calculate the capacitance value of the target row of the ion-type flexible pressure sensor in the m-row and n-column ion-type flexible pressure sensor array 111 based on the amplitude of the positive excitation voltage and the negative excitation voltage, the first detection voltage and the second detection voltage, and the capacitance value of the reference capacitor (Cr1-Crn). The target row here refers to the current selected row in the m-row and n-column ion-type flexible pressure sensor array 111. At this time, the target row is in the selected state, and the driving end of the ion-type flexible pressure sensor in the target row alternately inputs the positive excitation voltage and the negative excitation voltage.

[0061] In some embodiments, the control unit 122 may include analog-to-digital conversion (ADC) channels of a number corresponding to the number of columns n of the m-row and n-column ion-type flexible pressure sensors, and the output terminals of the operational amplifiers (OA1-OAn) corresponding to each column are respectively connected to the corresponding analog-to-digital conversion (ADC) channels. Under the combined effect of the excitation voltage S1 input to the driving terminal of the ion-type flexible pressure sensor of the target row and the reference voltage Vref input to the non-inverting input terminal of the operational amplifier (OA1-OAn) corresponding to each column, the first detection voltage and the second detection voltage output from the output terminal of the operational amplifier (OA1-OAn) are input to the analog-to-digital conversion (ADC) channel corresponding to the control unit 122, and the capacitance value of each ion-type flexible pressure sensor of the target row is calculated after analog-to-digital conversion.

[0062] The capacitance value calculation principle of the ion-type flexible pressure sensor in this embodiment can be combined with Figure 4 It is derived through the following formula. Figure 4 As shown, taking the capacitance-pressure conversion circuit 121 corresponding to the first column as an example, according to the virtual short principle of the operational amplifier, when the driving end of the ion-type flexible pressure sensor C11 inputs the excitation voltage S1 through the row selection switch SW1, the reference voltage Vref is input to the positive input end of the operational amplifier OA1, and the detection end of the ion-type flexible pressure sensor C11 is connected to the inverting input end of the operational amplifier OA1 through the column selection switch SWc1, then the voltage at both ends of the ion-type flexible pressure sensor C11 is changed and charge transfer will occur. Since the leakage of each pin of the operational amplifier OA1 is very small, the amount of charge changed in the ion-type flexible pressure sensor C11 is basically the same as the amount of charge changed in the reference capacitor Cr1. Assume that the amount of charge changed in the ion-type flexible pressure sensor C11 is expressed as , the charge change of reference capacitor Cr1 is expressed as , then we can conclude .

[0063] Assume that the voltage change of the ion-type flexible pressure sensor C11 is expressed as , the capacitance value of the ion-type flexible pressure sensor C11 is expressed as , the voltage change of the reference capacitor Cr1 is expressed as , the capacitance value of the reference capacitor Cr1 is expressed as , then we can get:

[0064] ;

[0065] Assuming that the reference voltage input to the non-inverting input terminal of the operational amplifier OA1 is expressed as Vref, the amplitude of the forward excitation voltage input to the driving terminal of the ion-type flexible pressure sensor C11 is expressed as , the amplitude of the negative excitation voltage is expressed as When the driving end of the ion-type flexible pressure sensor C11 changes from the input reference voltage to the input forward excitation voltage for a predetermined time through the row selection switch SW1, the input voltage of the driving end of the ion-type flexible pressure sensor C11 changes from the reference voltage Vref to At this time, the first detection voltage corresponding to the forward excitation voltage outputted from the output terminal of the operational amplifier OA1 is expressed as , then we can further get:

[0066] .

[0067] When the driving end of the ion-type flexible pressure sensor C11 changes from the input reference voltage to the input negative excitation voltage for a predetermined time through the row selection switch SW1, the input voltage of the driving end of the ion-type flexible pressure sensor C11 changes from the reference voltage Vref to At this time, the second detection voltage corresponding to the negative excitation voltage outputted from the output terminal of the operational amplifier OA1 is expressed as , then we can further get:

[0068] .

[0069] Subtracting the above two formulas, we can further deduce:

[0070] ;

[0071] Thus, formula (1) can be obtained as follows:

[0072] (1).

[0073] It can be seen that the capacitance value of the ion-type flexible pressure sensor C11 is highly correlated with the ratio of the difference between the first detection voltage and the second detection voltage to the sum of the amplitudes of the positive excitation voltage and the negative excitation voltage, and the capacitance value of the reference capacitor. Therefore, the control unit 122 can calculate the capacitance value of the ion-type flexible pressure sensor in the target row of the m-row and n-column ion-type flexible pressure sensors based on the amplitudes of the positive excitation voltage and the negative excitation voltage, the first detection voltage and the second detection voltage, and the capacitance value of the reference capacitor.

[0074] The sensing calculation method of the ion-type flexible pressure sensor of the control unit 122 can quickly and accurately calculate the capacitance value of the ion-type flexible pressure sensor of the target row by alternately inputting a positive excitation voltage and a negative excitation voltage to the driving end of the ion-type flexible pressure sensor based on the amplitudes of the positive excitation voltage and the negative excitation voltage, the difference between the first detection voltage and the second detection voltage, and the capacitance value of the reference capacitor; at the same time, when the row selection state of the target row is selected and the row selection states of other rows are not selected, the column selection state of each column is selected, that is, only the driving end of the ion-type flexible pressure sensor of the target row inputs the excitation voltage S1, and the driving end of the ion-type flexible pressure sensors of other rows inputs the reference voltage Vref. Because the column selection state of the ion-type flexible pressure sensors in each column is selected, the ion-type flexible pressure sensors in each column are selected. The detection end of the sensor is connected to the inverting input end of the corresponding operational amplifier. Since the reference voltage Vref is input to the positive input end of the operational amplifier, and the reference voltage Vref is also input to the driving end of the ion-type flexible pressure sensors in other rows, due to the voltage following effect of the operational amplifier (OA1-OAn) at this time, the voltages at both ends of the ion-type flexible pressure sensors in other rows are in a voltage balance state of the reference voltage Vref, so that the ion-type flexible pressure sensors in other rows are substantially in a charge clearing state, avoiding the crosstalk problem of the capacitance detection of the ion-type flexible pressure sensors in the target row; in addition, since the detection ends of the ion-type flexible pressure sensors in each column are respectively connected to the inverting input ends of the corresponding operational amplifiers, the capacitance changes of the ion-type flexible pressure sensors in different columns will not interfere with the capacitance detection of the ion-type flexible pressure sensors in other columns. Therefore, the embodiment of the present application can prevent the crosstalk phenomenon between the same row or the same column of the ion-type flexible pressure sensor array 111, significantly improve the detection accuracy of the signal processing module 120 for the ion-type flexible pressure sensor, and meet the needs of high-precision pressure distribution measurement in the plantar pressure sensing scenario.

[0075] The inertial sensing unit 140 in this embodiment may be one or more inertial measurement units (IMUs), which are configured in the insole body 110 and / or the signal processing module 120 and are used to collect gait spatial information of the object being measured.

[0076] In an optional embodiment of configuring an inertial sensing unit 140, in order to comprehensively capture gait spatial information, the inertial sensing unit 140 can be configured at specific positions of the insole body 110, such as the forefoot, arch and heel areas, which play different roles in the gait cycle, thereby providing rich kinematic data.

[0077] In another optional implementation of configuring the inertial sensor unit 140, the inertial sensor unit 140 can be integrated into the signal processing module 120, which not only simplifies the overall design of the device, but also facilitates the rapid exchange and processing of data, thereby improving the efficiency of data processing.

[0078] In some embodiments, the inertial sensing unit 140 includes at least one accelerometer and at least one gyroscope, wherein the accelerometer is used to measure the linear acceleration of the object under test in the three axes of space (usually X, Y, and Z axes), thereby obtaining static posture information to distinguish the user's motion state (such as walking, running, or standing). The gyroscope is used to measure the angular velocity of the object under test in the three axes of space, thereby obtaining dynamic rotation information, that is, the rotation of the user's foot during movement, so as to accurately capture the dynamic changes in the user's gait. The gait space information of the object under test is obtained by fusing the static posture information and the dynamic rotation information. In some embodiments, the inertial sensing unit 140 may also include a three-axis magnetometer / barometer for measuring acceleration and angular velocity, etc.

[0079] Furthermore, the signal processing module 120 automatically adjusts the amplitudes of the positive excitation voltage and the negative excitation voltage according to the gait space information of the measured object to match the sensing accuracy requirements for the plantar pressure under different motion states of the measured object.

[0080] It is important to understand that gait spatial information includes parameters such as gait cycle, step length, stride, step width, step frequency, step speed and foot deflection angle. Among them, a complete gait cycle includes the stance phase and the swing phase, which refers to the time interval from the heel of one foot touching the ground to the next time the same heel touches the ground again. Step length refers to the distance traveled from the heel of one foot touching the ground to the heel of the same foot touching the ground again. Stride refers to the distance from the toe of one foot to the toe of the other foot. Step width refers to the lateral distance between the two feet. Step frequency refers to the number of gait cycles per unit time, usually expressed in steps / minute. Step speed refers to the distance walked or run per unit time, usually expressed in meters / second. Foot deflection angle refers to the deflection angle of the foot relative to the forward direction, which can be used to analyze the gait characteristics and foot movement patterns of the subject.

[0081] The signal processing module 120 is configured to determine the current motion state of the object under test (such as stillness, walking, jogging, running, etc.) based on the gait spatial information. For example, a step frequency lower than a certain value is considered to be "slow walking", and a step frequency higher than a certain value is considered to be "fast running". Similarly, the walking speed can also be used to distinguish different motion states. And determine the range of the plantar force of the object under test in the current motion state. For example, the plantar force during "slow walking" is determined to fluctuate within a smaller numerical range, while the plantar force during "fast running" is determined to fluctuate within a larger numerical range.

[0082] Furthermore, the signal processing module 120 automatically adjusts the amplitude of the excitation signal according to the range of the force on the sole of the foot. Specifically, when it is determined that the force on the sole of the foot is in the first range (i.e., a small numerical range) in the current motion state of the measured object (for example, in the "slow walking" state), the amplitude of the positive excitation voltage and the negative excitation voltage is increased to more accurately measure the capacitance of the ion-type flexible pressure sensor; when it is determined that the force on the sole of the foot is in the second range (i.e., a large numerical range) in the current motion state of the measured object (for example, in the "fast running" state), the amplitude of the positive excitation voltage and the negative excitation voltage is reduced to prevent the conversion voltage of the capacitance-voltage conversion circuit 121 from overflowing.

[0083] This is because, based on the above , it can be known that there is an equiproportional relationship between the amplitude of the excitation signal and the amplitude of the change of the first detection voltage and the second detection voltage. At the same time, there is a positive correlation between the capacitance of the ionization type flexible pressure sensor and the force. The greater the force, the greater the capacitance, and the smaller the force, the smaller the capacitance. When the force on the sole of the foot is in a small numerical range, the change of the sole pressure may be very subtle. By increasing the amplitude of the excitation signal, these subtle changes can be more obviously captured and amplified, thereby improving the accuracy of the measurement. When the force on the sole of the foot is in a large numerical range, the change of the sole pressure may be very drastic. If the amplitude of the excitation signal is too large, it may cause the conversion voltage to exceed the processing range of the circuit, resulting in distortion of the measurement result. By reducing the amplitude of the excitation signal, it can help avoid the overflow of the conversion voltage of the capacitance-pressure conversion circuit 121, thereby maintaining the linearity and accuracy of the measurement, and increasing the measurement range. By automatically adjusting the amplitude of the excitation signal, more accurate testing and a wider measurement range can be achieved under different force conditions.

[0084] It should be noted that the "large" and "small" in this embodiment are based on specific thresholds or ranges. These thresholds or ranges can be dynamically adjusted based on experience, experimental data, or specific application requirements. For example, different people may have different cadences and speeds, so these thresholds may need to be personalized.

[0085] In one embodiment, the signal processing module 120 is also used to transmit the plantar pressure value and the gait space information to an electronic device, wherein the plantar pressure value includes the pressure distribution in different areas of the sole of the subject when the sole of the subject contacts the ground and the ground reaction force in the vertical direction, front-to-back direction and left-to-right direction of the sole, and the gait space information includes the gait cycle, step length, stride, step width, step frequency, step speed and foot deviation angle of the subject.

[0086] In this embodiment, the signal processing module 120 can transmit the plantar pressure value and gait space information to the electronic device through a wireless communication module (such as Bluetooth, Wi-Fi, zigbee, etc.), a wired transmission method (such as a serial port, a USB port, an Ethernet port, etc.) or a storage method (such as a TF card, an SD card, a FLASH storage chip, etc.). The electronic device can be a smart phone, a tablet computer or a dedicated display device, and the data analysis results are displayed through an application or a software interface. The user can view the real-time plantar pressure distribution map and the gait pattern analysis report through the electronic device. The gait pattern analysis report may include the pressure distribution map of each stage of the gait cycle, the gait speed, the step length, the step frequency and other key parameters. It can even provide a three-dimensional reconstruction and animation demonstration of the movement posture to intuitively display the user's gait pattern.

[0087] Through the above implementation, the plantar pressure sensing device 100 can not only accurately measure the plantar pressure distribution, but also perform comprehensive gait analysis and motion monitoring in combination with gait space information, providing users with more comprehensive and in-depth data support and services.

[0088] In summary, the plantar pressure sensing device 100 of the present application, on the one hand, comprehensively captures the pressure distribution of each area of ​​the sole of the foot by adopting an m-row and n-column ion-type flexible pressure sensor array 111, thereby realizing comprehensive monitoring of the plantar pressure. This array design not only improves the response speed and measurement accuracy of the sensor, but also ensures that the device can carefully monitor the pressure changes of the entire foot. On the other hand, the signal processing module 120 can convert the sensing capacitance signal generated by the sensor array into a detection voltage signal under the action of the excitation voltage, and further calculate the plantar pressure value, thereby realizing real-time processing of data. In addition, the inertial sensing unit 140 configured in the insole body 110 or the signal processing module 120 can collect the gait space information of the object being measured in real time. At the same time, the signal processing module 120 can automatically adjust the amplitude of the excitation voltage through the gait space information collected by the inertial sensing unit 140 to match the sensing accuracy requirements of the object being measured in different motion states. In summary, the plantar pressure sensing device 100 of the present application achieves high-precision, real-time plantar pressure sensing through the coordinated work of the ion-type flexible pressure sensor array 111, the signal processing module 120 and the inertial sensing unit 140, and can automatically adjust the sensing accuracy according to the motion state of the object being measured, ensuring that accurate data can be obtained under various motion states.

[0089] In addition, if Figure 5 As shown, an embodiment of the present application further proposes a plantar pressure sensing system, comprising a plantar pressure sensing device 100 and an electronic device 900 as described in any of the above embodiments, and the plantar pressure sensing device 100 and the electronic device 900 are communicatively connected.

[0090] In one embodiment, the electronic device 900 is used to receive the plantar pressure value and gait space information of the object under test transmitted by the plantar pressure sensing device 100, and generate a plantar pressure distribution diagram and a gait pattern analysis report based on the plantar pressure value and the gait space information. As a feasible implementation method for generating a plantar pressure distribution view, the electronic device 900 maps each pressure value to a corresponding two-dimensional or three-dimensional coordinate system according to the layout information of the ion-type flexible pressure sensor array 111. Based on the mapped data, a plantar pressure distribution view is generated.

[0091] In this embodiment, the electronic device 900 includes one or more processors; a memory, in which one or more programs are stored, wherein when the one or more programs are executed by one or more processors, the one or more processors execute the steps in the above-mentioned method embodiments.

[0092] In one embodiment, Figure 6, which shows a schematic diagram of the structure of an electronic device 900 for receiving the plantar pressure value transmitted by the plantar pressure sensing device 100. The electronic device 900 includes a central processing unit (CPU) 901, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 902 or the program loaded from the storage part 908 to the random access memory (RAM) 903. In the RAM 903, various programs and data required for the operation of the electronic device 900 are also stored. The CPU 901, the ROM 902, and the RAM 903 are connected to each other through the bus 904. The input / output (I / O) interface 905 is also connected to the bus 904.

[0093] The following components are connected to the I / O interface 905: an input section 906 including a keyboard, a mouse, etc.; an output section 907 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 908 including a hard disk, etc.; and a communication section 909 including a network interface card such as a LAN card, a modem, etc. The communication section 909 performs communication processing via a network such as the Internet. A drive 910 is also connected to the I / O interface 905 as needed. A removable medium 911, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 910 as needed, so that a computer program read therefrom is installed into the storage section 908 as needed.

[0094] In summary, the plantar pressure sensing device 100 and system of the present application, on the one hand, comprehensively captures the pressure distribution of each area of ​​the sole of the foot by adopting an m-row and n-column ion-type flexible pressure sensor array 111, thereby realizing comprehensive monitoring of the plantar pressure. This array design not only improves the response speed and measurement accuracy of the sensor, but also ensures that the device can carefully monitor the pressure changes of the entire foot. On the other hand, the signal processing module 120 can convert the sensing capacitance signal generated by the sensor array into a detection voltage signal under the action of the excitation voltage, and further calculate the plantar pressure value, thereby realizing real-time processing of data. In addition, the inertial sensing unit 140 configured in the insole body 110 or the signal processing module 120 can collect the gait space information of the object being measured in real time. At the same time, the signal processing module 120 can automatically adjust the amplitude of the excitation voltage through the gait space information collected by the inertial sensing unit 140 to match the sensing accuracy requirements of the object being measured in different motion states. In summary, the plantar pressure sensing device 100 of the present application achieves high-precision, real-time plantar pressure sensing through the coordinated work of the ion-type flexible pressure sensor array 111, the signal processing module 120 and the inertial sensing unit 140, and can automatically adjust the sensing accuracy according to the motion state of the object being measured, ensuring that accurate data can be obtained under various motion states.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application 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 application.

[0096] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A plantar pressure sensing device, characterized in that: The plantar pressure sensing device comprises: The insole body comprises an array of ion-type flexible pressure sensors arranged in an array form of m rows and n columns, wherein the ion-type flexible pressure sensor array is used to detect the plantar pressure of the object under test and convert the plantar pressure into a sensing capacitance signal, wherein the driving end of each row of the ion-type flexible pressure sensors in the ion-type flexible pressure sensor array is configured to input an excitation voltage, and m and n are integers greater than or equal to 1; A signal processing module, connected to the ion-type flexible pressure sensor array, for converting the sensing capacitance signal generated by the ion-type flexible pressure sensor array into a detection voltage signal under the action of the excitation voltage, and obtaining a plantar pressure value based on the detection voltage signal; The inertial sensing unit is configured in the insole body or the signal processing module, and is used to collect the gait space information of the object under test. The signal processing module is configured to automatically adjust the amplitude of the excitation voltage according to the gait space information of the object under test to match the sensing accuracy requirement of the plantar pressure under different motion states of the object under test.

2. The plantar pressure sensing device according to claim 1, characterized in that: The inertial sensing unit includes at least one acceleration sensor and at least one gyroscope, which are used to measure the static posture information and dynamic rotation information of the measured object, and fuse the static posture information and the dynamic rotation information to obtain the gait space information of the measured object.

3. The plantar pressure sensing device according to claim 2, characterized in that: The at least one acceleration sensor is used to measure the linear acceleration of the object under test in the three-axis directions of the spatial coordinate system to obtain the static posture information of the object under test, and the at least one gyroscope is used to measure the angular velocity of the object under test in the three-axis directions of the spatial coordinate system to obtain the dynamic rotation information of the object under test.

4. The plantar pressure sensing device according to claim 1, characterized in that: The driving end of each row of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array is configured to input an excitation voltage and a reference voltage respectively according to a row selection state, wherein the excitation voltage includes a positive excitation voltage and a negative excitation voltage input alternately; The signal processing module comprises: At least one capacitance-to-pressure conversion circuit, each capacitance-to-pressure conversion circuit comprises an operational amplifier and a reference capacitor, wherein two ends of the reference capacitor are respectively connected to the inverting input terminal and the output terminal of the operational amplifier; a reference voltage is input to the non-inverting input terminal of the operational amplifier, and a first detection voltage and a second detection voltage corresponding to the positive excitation voltage and the negative excitation voltage are output to the output terminal of the operational amplifier; the detection end of each column of the ion-type flexible pressure sensor in the ion-type flexible pressure sensor array is configured to be respectively connected to the corresponding inverting input terminal of the operational amplifier and the reference voltage according to the column selection state; A control unit is connected to the output end of the operational amplifier, and is used to calculate the capacitance value of the ion-type flexible pressure sensor in the target row in the ion-type flexible pressure sensor array based on the amplitudes of the positive excitation voltage and the negative excitation voltage, the first detection voltage and the second detection voltage, and the capacitance value of the reference capacitor, and convert the capacitance value of the ion-type flexible pressure sensor in the target row into a plantar pressure value.

5. The plantar pressure sensing device according to claim 4, characterized in that: The signal processing module is configured to automatically adjust the amplitudes of the positive excitation voltage and the negative excitation voltage according to the gait space information of the measured object to match the sensing accuracy requirements for the plantar pressure under different motion states of the measured object.

6. The plantar pressure sensing device according to claim 5, characterized in that: The signal processing module is configured to increase the amplitude of the positive excitation voltage and the negative excitation voltage based on the gait spatial information of the object under test, when it is judged that the force on the sole of the foot is within the first range in the current motion state of the object under test; and reduce the amplitude of the positive excitation voltage and the negative excitation voltage when it is judged that the force on the sole of the foot is within the second range in the current motion state of the object under test.

7. The plantar pressure sensing device according to claim 6, characterized in that: The signal processing module is also used to transmit the plantar pressure value and the gait space information to an electronic device, wherein the plantar pressure value includes the pressure distribution in different areas of the sole of the foot when the sole of the subject contacts the ground and the ground reaction force in the vertical direction, front-back direction and left-right direction of the sole, and the gait space information includes the gait cycle, step length, stride, step width, step frequency, step speed and foot deviation angle of the subject.

8. The plantar pressure sensing device according to claim 4, characterized in that: The driving end of each row of the electrical isolation flexible pressure sensors is configured to input the excitation voltage when the row selection state of the row is selection, and input the reference voltage when the row selection state of the row is non-selection.

9. The plantar pressure sensing device according to claim 4, characterized in that: The detection end of each column of the electrical flexible pressure sensor is configured to: connect to the inverting input end of the corresponding operational amplifier when the column selection state of the column is selected; and input the reference voltage when the column selection state of the column is not selected.

10. A plantar pressure sensing system, characterized in that: The plantar pressure sensing system includes a plantar pressure sensing device and an electronic device as described in any one of claims 1 to 9, the plantar pressure sensing device and the electronic device are communicatively connected, the electronic device is used to receive the plantar pressure value and the gait space information transmitted by the plantar pressure sensing device, and generate a plantar pressure distribution view and a gait pattern analysis report based on the plantar pressure value and the gait space information.

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