Knee joint pressure sensing device and system

Abstract

The present application provides a knee joint pressure sensing device and system, which belongs to the field of medical device technology. The device includes: a shell assembly, forming a sealed storage cavity; an ion-type pressure sensor array, arranged in an array form in the sealed storage cavity, for detecting knee joint pressure and converting the knee joint pressure into a sensing capacitance signal; a signal processing module, arranged in the sealed storage cavity, including a capacitance-pressure conversion unit, a control unit, an activation circuit unit, a wireless communication unit, a battery switch unit and a battery power supply unit; wherein the capacitance-pressure conversion unit is used to convert the sensing capacitance signal generated by the ion-type pressure sensor array into a detection voltage signal under the action of the excitation voltage of the control unit, and the control unit is used to obtain the knee joint pressure value based on the detection voltage signal. The present application can be applied to medical sterile liquid environments, and also has high pressure sensing accuracy and reliability.

Description

Technical Field

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

[0002] Knee osteoarthritis (OA) is a common chronic joint disease characterized by degeneration of articular cartilage. Total knee arthroplasty (TKA) replaces the damaged joint surface by inserting a special metal component and a high-molecular polyethylene liner between the femur and tibia, which can effectively relieve pain and restore joint function. It is an ideal choice for treating severe knee joint diseases.

[0003] The key to this operation is to ensure the tension balance of the soft tissues inside and outside the knee joint. If the tension of the inside and outside of the knee joint is unbalanced after surgery, it will lead to uneven pressure distribution of the femoral prosthesis on the gasket, which will accelerate the wear of the gasket, affect the effect of the operation, and even require a second operation. In traditional surgery, this balance mainly depends on the doctor's experience. Therefore, developing a measurement tool that can accurately evaluate the balance of soft tissues during surgery has become a research hotspot in the field of TKA.

[0004] The existing technology suggests that capacitive pressure sensing electrodes distributed in an array should be set on both sides of the soft tissue of the knee joint to fully capture the pressure distribution characteristics and improve the success rate of the operation. However, this knee joint pressure sensing device based on a capacitive pressure sensing array needs to be set in a small space generated during knee replacement surgery, and needs to be suitable for a medical sterile liquid environment, while also having high pressure sensing accuracy and reliability. Therefore, an improved knee joint pressure sensing device is urgently needed to solve these problems. Summary of the invention

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

[0006] In a first aspect, an embodiment of the present application provides a knee joint pressure sensing device, comprising:

[0007] A housing assembly forms a sealed receiving chamber;

[0008] An ion-type pressure sensor array is arranged in the sealed receiving cavity in the form of an array of m rows and n columns, and is used to detect knee joint pressure and convert the knee joint pressure into a sensing capacitance signal, where m and n are integers greater than or equal to 1;

[0009] A signal processing module is arranged in the sealed storage cavity, comprising a capacity-pressure conversion unit, a control unit, an activation circuit unit, a wireless communication unit, a battery switch unit and a battery power supply unit; wherein the activation circuit unit is used to generate a first switch signal based on the induced voltage signal generated by the induction coil to turn on the battery switch unit to realize the initial power supply of the control unit by the battery power supply unit; the control unit is used to establish a communication connection with a matching receiving device through the wireless communication unit and realize activation authentication, and then output a second switch signal to maintain the conduction of the battery switch unit to control the battery power supply unit to continuously supply power to the control unit;

[0010] The capacitance-pressure conversion unit is used to convert the sensing capacitance signal generated by the ion-type pressure sensor array into a detection voltage signal under the action of the excitation voltage of the control unit, and the control unit is also used to detect and obtain the knee joint pressure value based on the detection voltage signal.

[0011] In some embodiments, the control unit is also used to output a third switch signal to turn off the battery switch unit to interrupt the battery power supply unit to the control unit when the wireless communication unit fails to establish a communication connection with the corresponding receiving device or activation authentication fails within a predetermined time.

[0012] In some embodiments, the housing assembly includes:

[0013] An upper shell assembly, comprising a flexible upper shell having a surface shape fitting the knee joint and a hard upper shell disposed inside the flexible upper shell;

[0014] A lower shell component, wherein the lower shell component and the upper shell component are enclosed to form the sealed receiving chamber; the ion-type pressure sensor array is accommodated in the sealed receiving chamber on a side facing the upper shell component, and the signal processing module is accommodated in the sealed receiving chamber on a side facing the lower shell component;

[0015] The upper shell component includes a pressure transmission component, which is arranged between the upper shell component and the ion-type pressure sensor array and is used to transmit the knee joint pressure to the ion-type pressure sensor array.

[0016] In some embodiments, the pressure transmission component includes a force-conducting column fixed to the flexible upper shell and corresponding to the position of the isolated electric pressure sensor array, and a hard gasket adhered to the side of the isolated electric pressure sensor array facing the upper shell component.

[0017] In some embodiments, the capacity-pressure conversion unit includes:

[0018] At least one capacitance-to-pressure conversion circuit, each of which includes an operational amplifier and a reference capacitor, wherein two ends of the reference capacitor are respectively connected to an inverting input terminal and an output terminal of the operational amplifier, wherein the inverting input terminal of the operational amplifier is configured to be connected to a detection terminal of an ion-type pressure sensor of a corresponding column in the ion-type pressure sensor array; the non-inverting input terminal of the operational amplifier is configured to input a reference voltage, and the output terminal of the operational amplifier is configured to output a first detection voltage and a second detection voltage corresponding to the positive excitation voltage and the negative excitation voltage, respectively, when a positive excitation voltage and a negative excitation voltage are alternately input to a driving terminal of an ion-type pressure sensor of a target row in the ion-type pressure sensor array;

[0019] The control unit is connected to the output end of the operational amplifier, and is used to calculate the capacitance value of the ion-type pressure sensor in the target row in the ion-type 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 pressure sensor in the target row into the knee joint pressure value.

[0020] In some embodiments, the capacitance-pressure conversion unit includes a multi-way selection unit, which is used to sequentially connect the detection ends of at least one column of the ion-type pressure sensors in the ion-type pressure sensor array to the inverting input end of at least one operational amplifier.

[0021] In some embodiments, the wireless communication unit is further used to transmit the knee joint pressure value to an electronic device electrically connected to the receiving device via the receiving device.

[0022] In the second aspect, an embodiment of the present application proposes a knee joint pressure sensing system, comprising a knee joint pressure sensing device and a receiving device as described in any of the above embodiments, the knee joint pressure sensing device and the receiving device being communicatively connected, the receiving device comprising an electromagnetic induction unit and a receiving circuit unit, the electromagnetic induction unit being used to activate the knee joint pressure sensing device to start working based on the magnetic field generated by the built-in transmitting coil when the knee joint pressure sensing device is placed within a predetermined position range of the receiving device; the receiving circuit unit is used to receive the knee joint pressure value transmitted by the knee joint pressure sensing device, and transmit the knee joint pressure value to an electronic device.

[0023] In some embodiments, the receiving device further includes a USB data cable, which is electrically connected to the receiving circuit unit and is used to transmit the knee joint pressure value to an electronic device.

[0024] In some embodiments, the knee joint pressure sensing system further includes an electronic device, the receiving device is connected to the electronic device, and the electronic device is used to receive the knee joint pressure value transmitted by the receiving device and generate a knee joint pressure distribution view based on the knee joint pressure value.

[0025] Compared with the prior art, the beneficial effects of this application include:

[0026] On the one hand, by forming a sealed storage cavity through the shell assembly, it can ensure that the knee joint pressure sensing device is suitable for medical sterile liquid environment, and will not be affected by the invasion of external liquid and affect the performance or cause infection risk. On the other hand, by adopting an m-row and n-column ionized pressure sensor array, the pressure distribution on both sides of the soft tissue of the knee joint is fully captured, thereby realizing comprehensive monitoring of the knee joint 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 knee joint. On the third hand, the signal processing module integrating the capacitance-pressure conversion unit, the control unit, the activation circuit unit, the wireless communication unit, the battery switch unit and the battery power supply unit makes the device do not need an external power switch, which can avoid the problem of the knee joint pressure sensing device using an external power switch that is not conducive to the use of medical sterile liquid environment, further ensuring the capacitance sensing performance of the knee joint pressure sensing device used in surgery, avoiding intraoperative infection, and also improving the convenience of the device in the medical sterile liquid environment through intelligent power management. Fourthly, the device of the present application realizes the miniaturization of the knee joint pressure sensing device by optimizing the layout of the sensor array and the integration of the signal processing module, effectively reducing the production cost and complexity, so that it has significant economic benefits whether it is used to assist knee replacement surgery or to monitor the postoperative recovery of the knee joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] Figure 1 is an overall preview schematic diagram of the knee joint pressure sensing device according to the first embodiment of the present application;

[0029] Figure 2 is a schematic diagram of the structure of a knee joint pressure sensing device according to the first embodiment of the present application from a high perspective;

[0030] Figure 3 is a functional module diagram of a signal processing module in a knee joint pressure sensing device according to the first embodiment of the present application;

[0031] Figure 4 is a schematic diagram of the circuit structure of an activation circuit unit in the knee joint pressure sensing device according to the first embodiment of the present application;

[0032] Figure 5 is a schematic diagram of the circuit structure of the signal processing module in the knee joint pressure sensing device according to the first embodiment of the present application;

[0033] Figure 6 is a schematic diagram of the principle of a capacitance-voltage conversion circuit in a signal processing module according to the first embodiment of the present application;

[0034] Figure 7 is a schematic diagram of the circuit structure of a signal processing module in a knee joint pressure sensing device according to a second embodiment of the present application;

[0035] Figure 8 is a schematic diagram of the structure of a knee joint pressure sensing device according to a third embodiment of the present application from a low perspective;

[0036] Fig. 9 is a schematic diagram of the connection between a knee joint pressure sensing device and a receiving device in a knee joint pressure sensing system according to an embodiment of the present application;

[0037] Fig.10 is a schematic diagram of activation of a knee joint pressure sensing device and a receiving device in a knee joint pressure sensing system according to an embodiment of the present application;

[0038] Fig.11 is a schematic diagram of the connection between a receiving device and an electronic device in a knee joint pressure sensing system according to an embodiment of the present application;

[0039] Fig.12 It is a schematic diagram of the structure of an electronic device involved in the knee joint pressure sensing system according to an embodiment of the present application.

[0040] Description of the accompanying drawings: 100-knee joint pressure sensing device; 1-shell assembly; 10-upper shell assembly; 101-flexible upper shell; 102-hard upper shell; 103-pressure transmission assembly; 1031-force guide column; 1032-hard gasket; 111-sealed storage chamber; 2-ion-type pressure sensor array; 20-lower shell assembly; 21-first adhesive layer; 22-second adhesive layer; 3-signal processing module; 31-capacitance-pressure conversion unit; 311-capacitance-pressure conversion circuit; 32-control unit; 33-activation circuit unit; 331-sensing unit; 332-control unit; 333-activation circuit unit; 334-sensing unit; 335-sensing unit; 336-sensing unit; 337-sensing unit; 338-sensing unit; 339-sensing unit; 340-sensing unit; 341-sensing unit; 342-sensing unit; 343-sensing unit; 344-sensing unit; 345-sensing unit; 346-sensing unit; 347-sensing unit; 348-sensing unit; 349-sensing unit; 350-sensing unit; 351-sensing unit; 352-sensing unit; 353-sensing unit; 354-sensing unit; 355-sensing unit; 356-sensing unit; 357-sensing unit; 358-sensing unit; 359-sensing unit; 360-sensing unit; 361-sensing unit; 362-sensing unit; 363-sensing unit; 364- 32-voltage stabilizing unit; 34-wireless communication unit; 35-battery switch unit; 36-battery power supply unit; 37-multiplexing unit; 200-receiving device; 300-electronic device; 301-central processing unit (CPU); 302-read only memory (ROM); 303-random access memory (RAM); 304-bus; 305-input / output (I / O) interface; 306-input part; 307-output part; 308-storage part; 309-communication part; 312-removable medium; 313-drive. DETAILED DESCRIPTION

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] As mentioned above, the prior art suggests that an array of ion-type capacitive pressure sensing electrodes is set on both sides of the inner and outer sides of the soft tissue of the knee joint to fully capture the pressure distribution characteristics and improve the success rate of the operation. However, this knee joint pressure sensing device based on a capacitive pressure sensing array needs to be set in the narrow space generated during knee replacement surgery, and needs to be suitable for a medical sterile liquid environment, while also having high pressure sensing accuracy and reliability. Therefore, an improved knee joint pressure sensing device is urgently needed to solve these problems. To this end, the present application proposes a knee joint pressure sensing device and system, which can be suitable for a medical sterile liquid environment, while also having high pressure sensing accuracy and reliability.

[0046] Figure 1 is an overall preview diagram of the knee joint pressure sensing device 100 according to the first embodiment of the present application, Figure 2 FIG. 1 is a schematic diagram of a knee joint pressure sensing device 100 according to a first embodiment of the present application from a high perspective. Figure 1 and Figure 2 As shown, the knee joint pressure sensing device 100 of this embodiment includes:

[0047] The housing assembly 1 is provided with a sealed receiving chamber 111;

[0048] An ion-type pressure sensor array 2 is arranged in the sealed receiving cavity 111 in the form of an array of m rows and n columns, and is used to detect knee joint pressure and convert the knee joint pressure into a sensing capacitance signal, where m and n are integers greater than or equal to 1;

[0049] The signal processing module 3 is arranged in the sealed storage cavity 111, and includes a capacity-pressure conversion unit 31, a control unit 32, an activation circuit unit 33, a wireless communication unit 34, a battery switch unit 35 and a battery power supply unit 36; wherein the activation circuit unit 33 is used to generate a first switch signal based on the induced voltage signal generated by the induction coil to turn on the battery switch unit 35 to realize the initial power supply of the battery power supply unit 36 ​​to the control unit 32; the control unit 32 is used to establish a communication connection with the matching receiving device 200 through the wireless communication unit 34 and realize activation authentication, and then output a second switch signal to maintain the battery switch unit 35 turned on to control the battery power supply unit 36 ​​to continuously supply power to the control unit 32;

[0050] The capacitance-pressure conversion unit 31 is used to convert the sensing capacitance signal generated by the ion-type pressure sensor array 2 into a detection voltage signal under the action of the excitation voltage of the control unit 32, and the control unit 32 is also used to detect and obtain the knee joint pressure value based on the detection voltage signal.

[0051] In this embodiment, the housing component 1 refers to the part that constitutes the external structure and internal support of the knee joint pressure sensing device 100, and it provides a space for installation and protection of other components in the device. Specifically, a sealed storage cavity 111 is formed inside the housing component 1, and the sealed storage cavity 111 is used to accommodate key components such as the ionization pressure sensor array 2 and the signal processing module 3.

[0052] In some embodiments, the housing assembly 1 includes:

[0053] The upper shell assembly 10 comprises a flexible upper shell 101 having a surface shape fitting the knee joint and a hard upper shell 102 arranged inside the flexible upper shell 101;

[0054] The lower shell component 20 is enclosed with the upper shell component 10 to form the sealed receiving chamber 111; the ion-type pressure sensor array 2 is accommodated in the sealed receiving chamber 111 on a side facing the upper shell component 10, and the signal processing module 3 is accommodated in the sealed receiving chamber 111 on a side facing the lower shell component 20;

[0055] The flexible upper shell 101 in this embodiment is in direct contact with the soft tissue inside the knee joint, and its surface shape design needs to be highly fitted to the inner surface of the knee joint to ensure good contact between the device and the knee joint. The material of the flexible upper shell 101 can be soft and biocompatible silicone, TPU (thermoplastic polyurethane) or other medical-grade elastic materials. The hard upper shell 102 is located on the inner side of the flexible upper shell 101 to provide structural support and protection for the device. The material of the hard upper shell 102 can be medical-grade PC (polycarbonate) and is made by injection molding. As a feasible implementation method for connecting the flexible upper shell 101 and the hard upper shell 102, the flexible upper shell 101 and the hard upper shell 102 are formed into a whole through a secondary encapsulation process, which not only maintains the softness of the part in contact with the skin, but also provides the rigidity required for the internal structure.

[0056] The lower shell component 20 in this embodiment cooperates with the upper shell component 10 to form a closed sealed storage chamber 111 for accommodating the ionizing pressure sensor array 2 and the signal processing module 3. The lower shell component 20 can also be made of medical-grade PC injection molding to provide the necessary strength and durability. As some feasible implementation methods for connecting the upper shell component 10 and the lower shell component 20, the upper shell component 10 and the lower shell component 20 can be assembled together by biocompatible adhesives (such as UV light-cured UV glue, etc.) or mechanical connection methods (such as snaps, screws, etc.) to form a closed shell to protect the internal electronic components.

[0057] In this embodiment, the ion-type pressure sensor array 2 is a group of integrated ion-type pressure sensors. They are arranged in an array form and are used to detect and measure the pressure distribution applied thereon. Each sensor unit can independently detect pressure changes without interfering with each other. This independent detection capability enables the sensor array to capture the pressure changes in various areas inside the knee joint, thereby providing comprehensive pressure distribution information.

[0058] Specifically, the ion-type pressure sensor array 2 includes a flexible ion film dielectric layer and an electrode array layer consisting of m rows and n columns of electrodes. When the pressure inside the knee joint acts on the sensor array, the flexible ion film dielectric layer will deform, causing the capacitance between the electrodes to change, thereby converting the pressure inside the knee joint into a sensing capacitance signal. In this way, the ion-type pressure sensor array 2 can monitor and measure the pressure distribution inside the knee joint in real time, providing important data support for applications such as knee replacement surgery.

[0059] In this embodiment, the signal processing module 3 is a key component for realizing knee joint pressure sensing. On the one hand, the signal processing module 3 is fixed in the lower shell component 20 by fasteners such as adhesives, screws, and positioning columns to ensure the accurate positioning and stable installation of the signal processing module 3 in the lower shell component 20, so as to ensure the overall performance and reliability of the device. On the other hand, the signal processing module 3 is fastened and bonded to the ion-type pressure sensor array 2 by a first adhesive layer 21 (which can be formed by epoxy resin, silicone or other adhesives suitable for fixing electronic components) to prevent the signal processing module 3 from shifting due to vibration or other external forces during use. On the third hand, the signal processing module 3 is electrically connected to the ion-type pressure sensor array 2, and is responsible for converting the sensing capacitance signal generated by the ion-type pressure sensor array 2 into a detection voltage signal, thereby obtaining the knee joint pressure value of the object under test.

[0060] It can be understood that the combination of electrical connection and physical fixation in this embodiment can better ensure the stability and accuracy of signal transmission.

[0061] Specifically, Figure 3 FIG. 1 is a functional module diagram of the signal processing module 3 in the knee joint pressure sensing device 100 according to the first embodiment of the present application. Figure 3As shown, the signal processing module 3 includes a capacitance-pressure conversion unit 31, a control unit 32, an activation circuit unit 33, a wireless communication unit 34, a battery switch unit 35 and a battery power supply unit 36. The activation circuit unit 33 is used to generate a first switch signal based on the induced voltage signal generated by the induction coil to turn on the battery switch unit 35 to realize the initial power supply of the battery power supply unit 36 ​​to the control unit 32; the control unit 32 is used to establish a communication connection with the matching receiving device 200 through the wireless communication unit 34 and realize activation authentication, and then output a second switch signal to maintain the battery switch unit 35 turned on to control the battery power supply unit 36 ​​to continuously supply power to the control unit 32; the capacitance-pressure conversion unit 31 is used to convert the sensing capacitance signal generated by the ion-type pressure sensor array 2 into a detection voltage signal under the action of the excitation voltage of the control unit 32, and the control unit 32 is also used to calculate the sensing capacitance value of the ion-type pressure sensor corresponding to the detection voltage signal based on the analog-to-digital conversion of the detection voltage signal, and obtain the real pressure value of the ion-type pressure sensor based on the pressure calibration function of the ion-type pressure sensor.

[0062] In this embodiment, the activation circuit unit 33 generates a first switch signal based on the induced voltage signal generated by the induction coil to turn on the battery switch unit 35 to enable the battery power supply unit 36 ​​to initially power the control unit 32. Then, the control unit 32 establishes a communication connection with the matching receiving device 200 through the wireless communication unit 34 and realizes activation authentication, and then outputs a second switch signal to maintain the battery switch unit 35 turned on to control the battery power supply unit 36 ​​to continuously power the control unit 32. This can avoid the problem that the knee joint pressure sensing device 100 uses an external power switch, which is not conducive to the use of a medical sterile liquid environment. The external power switch usually needs to be manually touched or pressed. This method can easily cause the knee joint pressure sensing device 100 to be easily contaminated by bacteria or cause liquid to penetrate during use, affecting the capacitive sensing performance of the knee joint pressure sensing device 100 and easily causing intraoperative infection. The present application realizes the power supply activation of the control unit 32 of the knee joint pressure sensing device 100 through electromagnetic induction between the external matching receiving device 200 and the knee joint pressure sensing device 100, and the control unit 32 establishes a communication connection with the matching receiving device 200 through the wireless communication unit 34 and realizes activation authentication, which can further ensure the safety and reliability of the knee joint pressure sensing device 100 used as a medical device in surgery.

[0063] In some embodiments, Figure 4 FIG. 1 is a schematic diagram of the circuit structure of the activation circuit unit 33 in the knee joint pressure sensing device 100 according to the first embodiment of the present application. Figure 4 As shown, the activation circuit unit 33 includes an induction unit 331 and a voltage stabilizing unit 332. The induction unit 331 includes an inductor L1, a first capacitor C1, a second capacitor C2, and a third capacitor C3 connected in parallel to the inductor L1. The voltage stabilizing unit 332 includes a diode D1, a first voltage stabilizing diode D2, a second voltage stabilizing diode D3, a capacitor R1, and a fourth capacitor C4, wherein the anode of the diode D1 is connected to the other end of the third capacitor C3, and the anode of the diode D1 is connected to a reference voltage (Vref); the anode of the first voltage stabilizing diode D2 is connected to the cathode of the second voltage stabilizing diode D3, and is connected to the anode of the diode D1, and the capacitor R1 and the fourth capacitor C4 are both connected in parallel between the cathode of the first voltage stabilizing diode D2 and the anode of the second voltage stabilizing diode D3.

[0064] The battery switch unit 35 can be implemented as an NMOS tube N1, the gate of which is connected to the cathode of the first voltage stabilizing diode D2, the source of which is connected to the ground terminal of the control unit 32, the drain of which is connected to the battery ground terminal of the battery power supply unit 36, and is also connected to the anode of the second voltage stabilizing diode D3.

[0065] When the knee joint pressure sensing device 100 is placed in a predetermined position range of the receiving device 200, the sensing unit 331 generates an induced voltage signal at the other end of the third capacitor C3 based on the electromagnetic induction of the inductor L1. When the induced voltage signal is greater than the reference voltage (Vref), the diode D1 in the voltage stabilizing unit 332 is turned on and the induced voltage signal is stabilized at the reference voltage. Through the voltage stabilizing effect of the first voltage stabilizing diode D2, the second voltage stabilizing diode D3, the capacitor R1 and the fourth capacitor C4 in the voltage stabilizing unit 332, a high-level first switching signal Vp is generated at the negative electrode of the first voltage stabilizing diode D2. The first switching signal Vp is input into the gate of the NMOS tube N1 to turn on the battery switch unit 35 composed of the NMOS tube N1, so as to realize the initial power supply of the control unit 32 by the battery power supply unit 36. This process ensures that the battery power supply unit 36 ​​will start to supply power to the control unit 32 only when the induced voltage signal reaches a certain intensity threshold, thereby avoiding false triggering caused by slight changes in the electromagnetic environment. After receiving the initial power supply, the control unit 32 establishes a communication connection with the matching receiving device 200 through the wireless communication unit 34. This process also includes an activation authentication step, which may involve steps such as identity authentication and data encryption of the knee joint pressure sensing device 100 to ensure the safety and reliability of the knee joint pressure sensing device 100 used as a medical device in surgery. Once the communication connection is established and the activation authentication is successful, the control unit 32 will output a second switch signal, which is a high-level signal that can replace the first switch signal Vp to maintain the conduction of the battery switch unit 35 to control the battery power supply unit 36 ​​to continuously supply power to the control unit 32. This mechanism ensures that the knee joint pressure sensing device 100 can continue to work under normal working conditions and ensure the sensing of knee joint pressure.

[0066] In some embodiments, the control unit 32 is also used to output a third switch signal to turn off the battery switch unit 35 when the wireless communication unit 34 fails to establish a communication connection with the matching receiving device 200 or the activation authentication fails within a predetermined time. The third switch signal is a low-level signal input to the gate of the NMOS tube N1, which will cause the source and drain of the NMOS tube N1 to be turned off, thereby interrupting the battery power supply unit 36 ​​from supplying power to the control unit 32, so as to achieve energy saving and safety protection.

[0067] In some embodiments, the wireless communication unit 34 is further used to transmit the knee joint pressure value to an electronic device 300 electrically connected to the receiving device 200 via the receiving device 200. The communication connection method adopted can be a wireless communication method such as Bluetooth, Wi-Fi, Zigbee, etc., which is not limited in this embodiment.

[0068] In some embodiments, Figure 5 FIG. 1 is a schematic diagram of the circuit structure of the signal processing module 3 in the knee joint pressure sensing device 100 according to the first embodiment of the present application. Figure 5 As shown, the signal processing module 3 includes a capacity-pressure conversion unit 31 and a control unit 32; wherein the capacity-pressure conversion unit 31 includes:

[0069] At least one capacitance-pressure conversion circuit 311, each capacitance-pressure conversion circuit 311 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 inverting input terminal of the operational amplifier (OA1-OAn) is configured to be connected to the detection terminal of the ion-type pressure sensor of the corresponding column in the ion-type pressure sensor array 2; the non-inverting input terminal of the operational amplifier (OA1-OAn) is configured to input a reference voltage, and the output terminal of the operational amplifier (OA1-OAn) is configured to output a first detection voltage and a second detection voltage corresponding to the positive excitation voltage and the negative excitation voltage, respectively, when the driving terminal of the ion-type pressure sensor of the target row in the ion-type pressure sensor array 2 is alternately input with a positive excitation voltage and a negative excitation voltage;

[0070] The control unit 32 is connected to the output end of the operational amplifier (OA1-OAn), and is used to calculate the capacitance value of the ion-type pressure sensor in the target row in the ion-type pressure sensor array 2 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 (Cr1-Crn), and convert the capacitance value of the ion-type pressure sensor in the target row into the knee joint pressure value of the object under test.

[0071] In this embodiment, the ion-type pressure sensor array 2 includes m rows and n columns of ion-type pressure sensors, where m and n are integers greater than or equal to 1. The m rows and n columns of ion-type pressure sensors 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 pressure sensor in each row of ion-type pressure sensors in the ion-type pressure sensor array 2 has a driving end and a detection end, wherein the driving end of each row of ion-type pressure sensors is connected to an excitation voltage S1, and the excitation voltage S1 is an alternately input positive excitation voltage and a negative excitation voltage. In one embodiment, the driving end of each row of ion-type pressure sensors inputs the positive excitation voltage and the negative excitation voltage through at least one selection switch (SW1-SWm).

[0072] In this embodiment, each capacitance-pressure conversion circuit 311 includes an operational amplifier (OA1-OAn) and a reference capacitor (Cr1-Crn), and the 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), and the inverting input terminal of the operational amplifier (OA1-OAn) is configured to be connected to the detection end of the ion-type pressure sensor of the corresponding column in the ion-type pressure sensor array 2. For example, for the capacitance-pressure conversion circuit 311 composed of the operational amplifier OA1 and the reference capacitor Cr1, the inverting input terminal of the operational amplifier OA1 is connected to the detection terminal of the first column of ion-type pressure sensors C11-Cm1; for the capacitance-pressure conversion circuit 311 composed of the operational amplifier OA2 and the reference capacitor Cr2, the inverting input terminal of the operational amplifier OA2 is connected to the detection terminal of the second column of ion-type pressure sensors C12-Cm2; and so on, for the capacitance-pressure conversion circuit 311 composed of the operational amplifier OAn and the reference capacitor Crn, the inverting input terminal of the operational amplifier OAn is connected to the detection terminal of the nth column of ion-type pressure sensors C1n-Cmn.

[0073] In this embodiment, in each capacitance-pressure conversion circuit 311, the non-phase input terminal of the operational amplifier (OA1-OAn) inputs a driving voltage S0, and the driving voltage S0 is equal to a fixed reference voltage. When the driving terminal of each row of the ion-type pressure sensor alternately inputs a positive excitation voltage and a negative excitation voltage, the output terminal of the operational amplifier (OA1-OAn) can output a first detection voltage and a second detection voltage corresponding to the positive excitation voltage and the negative excitation voltage, respectively, and the first detection voltage and the second detection voltage can be detected by a control unit 32 connected to the output terminal of the operational amplifier (OA1-OAn). The control unit 32 can calculate the capacitance value of the ion-type pressure sensor of the target row in the m-row and n-column ion-type pressure sensor array 2 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).

[0074] In some embodiments, the control unit 32 may include analog-to-digital conversion (ADC) channels corresponding to the number of columns n of the m-row and n-column ion-type pressure sensor array 2, and the output end of the operational amplifier (OA1-OAn) corresponding to each column is respectively connected to the corresponding analog-to-digital conversion (ADC) channel. Under the joint action of the driving voltage S0 (i.e., the reference voltage Vref) input to the non-phase input end of the operational amplifier (OA1-OAn) and the excitation voltage S1 input to the driving end of the ion-type pressure sensor of the target row, the first detection voltage and the second detection voltage output from the output end of the operational amplifier (OA1-OAn) are input to the analog-to-digital conversion (ADC) channel corresponding to the control unit 32, and the capacitance value of each ion-type pressure sensor of the target row is calculated after analog-to-digital conversion.

[0075] The capacitance value calculation principle of the ionization pressure sensor in this embodiment can be combined with Figure 6 It is derived through the following formula. Figure 6 As shown, it is assumed that the capacitance value of the ionization pressure sensor C11 is expressed as , the capacitance value of the reference capacitor Cr1 is expressed as The reference voltage input to the positive input terminal of the operational amplifier OA1 is expressed as Vref, and the amplitude of the positive excitation voltage input to the driving terminal of the ionization pressure sensor C11 is expressed as , the amplitude of the negative excitation voltage is expressed as When the driving end of the ionization type pressure sensor C11 first changes from the input reference voltage to the input forward excitation voltage for a predetermined time, the input voltage of the driving end of the ionization type pressure sensor C11 changes from the reference voltage Vref to At this time, the first detection voltage corresponding to the forward excitation voltage at the output end of the operational amplifier OA1 is expressed as , then we can further get:

[0076] .

[0077] When the driving end of the ionization pressure sensor C11 changes from the input reference voltage to the input negative excitation voltage for a predetermined time, the input voltage of the driving end of the ionization pressure sensor C11 changes from the reference voltage Vref to At this time, the second detection voltage corresponding to the negative excitation voltage at the output terminal of the operational amplifier OA1 is expressed as , then we can further get:

[0078] .

[0079] Subtracting the above two formulas, we can further deduce:

[0080] ;

[0081] Thus, formula (1) can be obtained as follows:

[0082] (1).

[0083] It can be seen that the capacitance value of the ion-type 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 32 can calculate the capacitance value of the ion-type pressure sensor in the target row of the m-row and n-column ion-type 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.

[0084] The sensing calculation method of the ion-type pressure sensor of the control unit 32 can quickly and accurately calculate the capacitance value of the ion-type pressure sensor of the target row 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 by alternately inputting a positive excitation voltage and a negative excitation voltage into the driving end of the ion-type pressure sensor. This can significantly improve the detection accuracy of the signal processing module 3 for the ion-type pressure sensor, and meet the needs of high-precision pressure distribution measurement in the knee joint pressure sensing scenario.

[0085] In summary, the knee joint pressure sensing device 100 of the present application, on the one hand, forms a sealed storage cavity through the shell assembly, which can ensure that the knee joint pressure sensing device is suitable for medical sterile liquid environment, and will not be affected by the invasion of external liquid and affect the performance or cause infection risk. On the other hand, by adopting an m-row and n-column ion-type pressure sensor array, the pressure distribution on both sides of the inner and outer sides of the knee joint soft tissue is fully captured, thereby realizing comprehensive monitoring of the knee joint 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 knee joint. On the third hand, the signal processing module integrating the capacitance-pressure conversion unit, the control unit, the activation circuit unit, the wireless communication unit, the battery switch unit and the battery power supply unit makes the device do not need an external power switch, which can avoid the problem of the knee joint pressure sensing device 100 using an external power switch, which is not conducive to the use of the medical sterile liquid environment, and further ensures the capacitive sensing performance of the knee joint pressure sensing device 100 used in surgery, avoiding the infection during surgery, and also improving the convenience of the device in the medical sterile liquid environment through intelligent power management. Fourthly, the device of the present application realizes the miniaturization of the knee joint pressure sensing device by optimizing the layout of the sensor array and the integration of the signal processing module, effectively reducing the production cost and complexity, so that it has significant economic benefits whether it is used to assist knee replacement surgery or to monitor the postoperative recovery of the knee joint.

[0086] Figure 7 FIG. 1 is a schematic diagram of the circuit structure of the signal processing module 3 in the knee joint pressure sensing device 100 according to the second embodiment of the present application. Figure 7 As shown, the signal processing module 3 of this embodiment, based on any of the aforementioned implementations, further includes: a multi-way selection unit 37, which is used to connect the detection ends of at least one column of the ion-type pressure sensors in the ion-type pressure sensor array to the inverting input end of at least one operational amplifier in sequence.

[0087] In this embodiment, the number a of the capacitance-pressure conversion circuits 311 depends on the number a of the analog-to-digital conversion (ADC) channels of the control unit 32. When the number a of the analog-to-digital conversion (ADC) channels of the control unit 32 is less than the number n of columns of the m-row and n-column ion-type pressure sensors, that is, it is insufficient to meet the detection requirements of all columns of the m-row and n-column ion-type pressure sensors, the detection ends of the n-column ion-type pressure sensors can be connected to the inverting input ends of the corresponding operational amplifiers (OA1-OAa) in a capacitance-pressure conversion circuit 311 in a sequentially selected manner through the multi-way selection unit 37.

[0088] For example, when the number of analog-to-digital conversion (ADC) channels of the control unit 32 is 1, the number of the capacitive-pressure conversion circuit 311 is 1, and the one capacitive-pressure conversion circuit 311 includes an operational amplifier (OA1). At this time, the multiplexer 37 can connect the detection ends of all n columns of ion-type pressure sensors to the inverting input end of the operational amplifier (OA1) of the capacitive-pressure conversion circuit 311 in a sequentially selected manner; when the number of analog-to-digital conversion (ADC) channels of the control unit 32 is 2, the number of the capacitive-pressure conversion circuit 311 is 2, and the two capacitive-pressure conversion circuits 311 include operational amplifiers (OA1, OA2). At this time, the multiplexer 37 can connect all the detection ends of the ion-type pressure sensors of the n columns to the inverting input end of the operational amplifier (OA1) of the capacitive-pressure conversion circuit 311 when the column selection state of the column is selected. The detection ends of every two columns of ion-type pressure sensors in the n columns of ion-type pressure sensors are connected to the inverting input ends of the operational amplifiers (OA1, OA2) of the capacitive-pressure conversion circuit 311 in a sequentially selected manner; similarly, by analogy, when the number of analog-to-digital conversion (ADC) channels of the control unit 32 is a, a is less than n, the number of capacitive-pressure conversion circuits 311 is a, and the a capacitive-pressure conversion circuits 311 include operational amplifiers (OA1-OAa). At this time, the multi-way selection unit 37 can connect the detection ends of every a columns of ion-type pressure sensors in all the n columns of ion-type pressure sensors to the inverting input ends of the operational amplifiers (OA1-OAa) of the capacitive-pressure conversion circuit 311 in a sequentially selected manner.

[0089] It can be understood that when the number of analog-to-digital conversion (ADC) channels of the control unit 32 is n, the number of the capacitive-pressure conversion circuits 311 is n, and the n capacitive-pressure conversion circuits 311 include operational amplifiers (OA1-OAn). At this time, all the paths of the multi-way selection unit 37 are enabled, that is, the detection ends of all n columns of ion-type pressure sensors can be simultaneously connected to the inverting input ends of the operational amplifiers (OA1-OAn) of the n capacitive-pressure conversion circuits 311.

[0090] In this embodiment, through the multi-way selection unit 37, the detection end of at least one column of ion-type pressure sensors can be connected to the inverting input end of at least one operational amplifier (OA1-OAa) in sequence, so that even if the number of analog-to-digital conversion (ADC) channels of the control unit 32 is limited, it can still ensure that the detection requirements of all ion-type pressure sensors are met. In summary, this embodiment can not only effectively utilize limited hardware resources and avoid waste of resources, but also ensure the detection accuracy and efficiency of the device. Through the flexible switching and control of the multi-way selection unit 37, efficient management and data collection of the ion-type pressure sensor array 2 are achieved, providing a reliable basis for subsequent data analysis and decision-making.

[0091] Figure 8 FIG. 2 is a schematic diagram of a knee joint pressure sensing device 100 according to a third embodiment of the present application from a low perspective. Figure 8 As shown, in order to ensure that the knee joint pressure sensing device 100 can more accurately measure the pressure changes inside the knee joint, the upper shell component 10 of this embodiment, on the basis of any of the aforementioned implementations, further includes: a pressure transmission component 103, wherein the pressure transmission component 103 is arranged between the upper shell component 10 and the ion-type pressure sensor array 2, and is used to transmit the knee joint pressure to the ion-type pressure sensor array 2.

[0092] In this embodiment, the pressure transmission component 103 includes a force guiding column 1031 fixed to the flexible upper shell 101 corresponding to the position of the isolated pressure sensor array 2 and a hard gasket 1032 adhered to the side of the isolated pressure sensor array 2 facing the upper shell component 10.

[0093] First, the force-guiding column 1031 is a structure fixed on the flexible upper shell 101, and its number and position correspond one-to-one to the sensor points in the ion-type pressure sensor array 2. The function of each force-guiding column 1031 is to effectively transfer the pressure from the inside of the knee joint to the corresponding sensor point, thereby ensuring that the sensor can accurately detect the pressure change.

[0094] As a feasible implementation method of forming a force-guiding column, the force-guiding column and the flexible upper shell 101 can be integrally formed by precision injection molding or mold molding. The shape and size of the force-guiding column can be designed according to the mechanical environment inside the knee joint and the size of the sensor, such as cylindrical or conical, to ensure uniformity and accuracy of pressure transmission, which is not limited in this embodiment.

[0095] On the second aspect, the hard gasket 1032 is adhered to the side of the ion-type pressure sensor array 2 facing the upper shell assembly 10 through the second adhesive layer 22 (which can be formed by epoxy resin, silicone or other adhesives suitable for fixing electronic components), and its number and position correspond one-to-one to the sensor points in the ion-type pressure sensor array 2. That is, the hard gasket 1032 is located between the ion-type pressure sensor array 2 and the force guide column 1031, which can effectively protect the ion-type pressure sensor array 2 from mechanical damage and extend the service life of the sensor. The hard gasket 1032 can be a metal gasket made of high-strength and corrosion-resistant materials such as medical-grade stainless steel and titanium alloy, which can maintain long-term stability in the in vivo environment, thereby extending the service life of the entire sensor.

[0096] In addition, experimental tests show that the hard gasket 1032 can not only protect the ion membrane, but also improve the sensitivity of the sensor. This is because the hard gasket 1032 has good rigidity and can more effectively transmit and disperse pressure, so that the sensor can detect pressure changes more accurately.

[0097] In this embodiment, through the synergistic effect of the force guide column 1031 and the hard gasket 1032, the pressure transmission component 103 can ensure that the pressure inside the knee joint is accurately and evenly transmitted to each sensor point of the ion-type pressure sensor array 2, thereby improving the accuracy and reliability of pressure sensing.

[0098] In addition, if Fig. 9 As shown, the embodiment of the present application also proposes a knee joint pressure sensing system, comprising a knee joint pressure sensing device 100 and a receiving device 200 as described in any of the above embodiments, and the knee joint pressure sensing device 100 and the receiving device 200 are communicatively connected. The receiving device 200 comprises an electromagnetic induction unit and a receiving circuit unit, wherein the electromagnetic induction unit is used to activate the knee joint pressure sensing device 100 to start working based on the magnetic field generated by the built-in transmitting coil when the knee joint pressure sensing device 100 is placed in a predetermined position range of the receiving device 200; the receiving circuit unit is used to receive the knee joint pressure value transmitted by the knee joint pressure sensing device 100, and transmit the knee joint pressure value to an electronic device.

[0099] Next, the operating indicator light of the receiving device 200 lights up, indicating that the knee joint pressure sensing device 100 has started to operate and is working normally. This indicator light can help the user confirm whether the knee joint pressure sensing device 100 has been successfully activated and can monitor the operating status of the system.

[0100] In some embodiments, the receiving device 200 further includes a USB data cable, which is electrically connected to the receiving circuit unit and is used to transmit the knee joint pressure value to the electronic device 300 .

[0101] Fig.11 FIG. 2 is a schematic diagram of the connection between the receiving device 200 and the electronic device 300 in the knee joint sensing system according to an embodiment of the present application. Fig.11 As shown, the knee joint pressure sensing system also includes: an electronic device 300, the receiving device 200 is connected to the electronic device 300, and the electronic device 300 is used to receive the knee joint pressure value transmitted by the receiving device 200, and generate a knee joint pressure distribution view based on the knee joint pressure value.

[0102] As a feasible implementation method of generating a knee joint pressure distribution view, the electronic device 300 maps each pressure value to a corresponding two-dimensional or three-dimensional coordinate system according to the layout information of the ion-type pressure sensor array 2. Based on the mapped data, a knee joint pressure distribution view is generated.

[0103] In this embodiment, the electronic device 300 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.

[0104] In one embodiment, Fig.12 , which shows a schematic diagram of the structure of an electronic device 300 for receiving the knee joint pressure value transmitted by the receiving device 200. The electronic device 300 includes a central processing unit (CPU) 301, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 302 or the program loaded from the storage part 308 to the random access memory (RAM) 303. In the RAM 303, various programs and data required for the operation of the electronic device 300 are also stored. The CPU 301, the ROM 302 and the RAM 303 are connected to each other through the bus 304. The input / output (I / O) interface 305 is also connected to the bus 304.

[0105] The following components are connected to the I / O interface 305: an input section 306 including a keyboard, a mouse, etc.; an output section 307 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 308 including a hard disk, etc.; and a communication section 309 including a network interface card such as a LAN card, a modem, etc. The communication section 309 performs communication processing via a network such as the Internet. A drive 313 is also connected to the I / O interface 305 as needed. A removable medium 312, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 313 as needed, so that a computer program read therefrom is installed into the storage section 308 as needed.

[0106] In summary, the knee joint pressure sensing device and system of the present application, on the one hand, by adopting an m-row and n-column ion-type pressure sensor array 2, comprehensively captures the pressure distribution on both sides of the inner and outer sides of the knee joint soft tissue, thereby realizing comprehensive monitoring of the knee joint 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 knee joint. On the other hand, by reasonably configuring the driving end of each row of ion-type pressure sensors, the excitation voltage and the reference voltage are respectively input according to the row selection state, which effectively prevents the signal interference between adjacent sensors and improves the accuracy and reliability of the measurement. At the same time, the signal processing module 3 can convert the sensing capacitance signal generated by the sensor array into a detection voltage signal under the action of the positive excitation voltage and the negative excitation voltage, and further calculate the knee joint pressure value, realizing the real-time processing of the data. In addition, the device of the present application effectively reduces the production cost and complexity by optimizing the layout of the sensor array and the integration of the signal processing module 3, so that whether it is used to assist knee replacement surgery or to monitor the postoperative recovery of the knee joint, it has significant economic benefits.

[0107] 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.

[0108] 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 knee joint pressure sensing device, characterized in that: The knee joint pressure sensing device comprises: A shell assembly forms a sealed receiving chamber; An ion-type pressure sensor array is arranged in the sealed receiving cavity in the form of an array of m rows and n columns, and is used to detect knee joint pressure and convert the knee joint pressure into a sensing capacitance signal, where m and n are integers greater than or equal to 1; A signal processing module is arranged in the sealed storage cavity, comprising a capacity-pressure conversion unit, a control unit, an activation circuit unit, a wireless communication unit, a battery switch unit and a battery power supply unit; wherein the activation circuit unit is used to generate a first switch signal based on the induced voltage signal generated by the induction coil to turn on the battery switch unit to realize the initial power supply of the control unit by the battery power supply unit; the control unit is used to establish a communication connection with a matching receiving device through the wireless communication unit and realize activation authentication, and then output a second switch signal to maintain the conduction of the battery switch unit to control the battery power supply unit to continuously supply power to the control unit; The capacitance-pressure conversion unit is used to convert the sensing capacitance signal generated by the ionization pressure sensor array into a detection voltage signal under the action of the excitation voltage of the control unit, and the control unit is also used to detect and obtain the knee joint pressure value based on the detection voltage signal; The shell assembly includes: an upper shell assembly, which includes a flexible upper shell having a surface shape that fits the knee joint and a hard upper shell arranged on the inner side of the flexible upper shell; a lower shell assembly, which is enclosed with the upper shell assembly to form the sealed storage cavity; the ion-type pressure sensor array is accommodated in the sealed storage cavity on the side facing the upper shell assembly, and the signal processing module is accommodated in the sealed storage cavity on the side facing the lower shell assembly; the upper shell assembly includes a pressure transmission assembly, which is arranged between the upper shell assembly and the ion-type pressure sensor array, and is used to transmit the knee joint pressure to the ion-type pressure sensor array.

2. The knee joint pressure sensing device according to claim 1, characterized in that: The control unit is also used to output a third switch signal to turn off the battery switch unit to interrupt the battery power supply unit to supply power to the control unit when the wireless communication unit fails to establish a communication connection with the matching receiving device or activation authentication fails within a predetermined time.

3. The knee joint pressure sensing device according to claim 2, characterized in that: The pressure transmission component includes a force-conducting column fixed to the flexible upper shell and corresponding to the position of the isolated electric pressure sensor array, and a hard gasket adhered to a side of the isolated electric pressure sensor array facing the upper shell component.

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

5. The knee joint pressure sensing device according to claim 4, characterized in that: The capacitance-pressure conversion unit comprises a multi-way selection unit, and the multi-way selection unit is used to sequentially connect the detection ends of at least one column of the ion-type pressure sensors in the ion-type pressure sensor array to the inverting input end of at least one operational amplifier.

6. The knee joint pressure sensing device according to claim 1, characterized in that: The wireless communication unit is further used to transmit the knee joint pressure value to an electronic device electrically connected to the receiving device via the receiving device.

7. A knee joint pressure sensing system, characterized in that: The knee joint pressure sensing system comprises a knee joint pressure sensing device and a receiving device as claimed in any one of claims 1 to 6, wherein the knee joint pressure sensing device is communicatively connected with the receiving device, and the receiving device comprises an electromagnetic induction unit and a receiving circuit unit, wherein the electromagnetic induction unit is used to activate the knee joint pressure sensing device to start working based on the magnetic field generated by the built-in transmitting coil when the knee joint pressure sensing device is placed in a predetermined position range of the receiving device; The receiving circuit unit is used for receiving the knee joint pressure value transmitted by the knee joint pressure sensing device, and transmitting the knee joint pressure value to the electronic device.

8. A knee joint pressure sensing system as claimed in claim 7, characterized in that: The receiving device also includes a USB data cable, which is electrically connected to the receiving circuit unit and is used to transmit the knee joint pressure value to an electronic device.

9. A knee joint pressure sensing system as claimed in claim 8, characterized in that: The knee joint pressure sensing system also includes an electronic device, the receiving device is connected to the electronic device, and the electronic device is used to receive the knee joint pressure value transmitted by the receiving device and generate a knee joint pressure distribution view based on the knee joint pressure value.

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