Flexible pressure monitoring system for hip replacement surgery

Abstract

The invention discloses a flexible pressure monitoring system for hip replacement surgery, and belongs to the technical field of biomedical instruments. The flexible pressure monitoring system comprises a flexible front-end signal acquisition module, a rear-end signal processing module and an upper computer system, the flexible front-end signal acquisition module is connected with the rear-end signal processing module, and the rear-end signal processing module is connected with the upper computer system; the flexible front-end signal acquisition module comprises a flexible pressure sensor, and the flexible pressure sensor is arranged at a hip joint; the flexible pressure sensor comprises a flexible substrate, an electrode layer, a spacing layer, a sensitive layer and a packaging layer. According to the flexible pressure monitoring system, the uncertainty that the operation effect is judged only according to experience in the hip joint replacement operation process is made up, clear pressure distribution at the hip joint in the operation process can be provided for surgeons, and objective mechanical data are provided for selection and adaptation of prostheses.

Description

Technical Field

[0001] The invention relates to the technical field of biomedical instruments, and in particular to a flexible pressure monitoring system for hip replacement surgery. Background Art

[0002] Total hip arthroplasty (THA) is currently the best treatment option for end-stage hip disease, which can effectively solve patients' hip pain and dysfunction. The biomechanical goal of total hip arthroplasty is to achieve the correct femoral head rotation center, as well as accurate leg length, femoral and acetabular component offset and positioning to stabilize the hip joint.

[0003] In a total hip replacement, the surgeon has the choice of accessing the acetabulum or femoral head, removing the damaged cartilage first, and then inserting the acetabular portion of the implant into the acetabulum. A metal stem is inserted into the hollow femur. A trial femoral head is attached to the top of the femoral stem and joins the femoral and acetabular components together. The cup, head, and stem portions are available in a range of sizes to customize the size of the implant to the patient’s needs. The surgeon will assess the position, stability, leg length, and soft tissue balance of the trial component by checking the joint anteversion, moving the hip through a full range of joint motion, repositioning and adjusting the size of the implant, and performing trial fits. Once it is determined that the trial implant is in the correct position with the correct soft tissue tension, it will be exchanged with the final implant. During the above trial phase, surgeons currently lack objective force data to assist with precise positioning and balance. Summary of the invention

[0004] Based on the above technical problems, the present invention proposes a flexible pressure monitoring system for hip replacement surgery.

[0005] The technical solution adopted by the present invention is:

[0006] A flexible pressure monitoring system for hip replacement surgery, comprising a flexible front-end signal acquisition module, a back-end signal processing module and a host computer system, wherein the flexible front-end signal acquisition module is connected to the back-end signal processing module, and the back-end signal processing module is connected to the host computer system;

[0007] The flexible front-end signal acquisition module includes a flexible pressure sensor, which is placed at the hip joint;

[0008] The flexible pressure sensor includes a flexible substrate, an electrode layer, a spacer layer, a sensitive layer and a packaging layer, wherein the spacer layer is arranged between the electrode layer and the sensitive layer, and the electrode layer, the spacer layer and the sensitive layer are all arranged between the flexible substrate and the packaging layer to form a sandwich structure;

[0009] The electrode layer includes several arc electrodes with different diameters, all of which are concentrically arranged, and interdigitated electrodes are arranged around the arc electrodes; the spacing layer includes several arc structures with different diameters, correspondingly covering several arc electrodes with different diameters; the sensitive layer covers the area between adjacent arc electrodes.

[0010] Furthermore, the flexible pressure sensor is attached between the acetabular outer cup and the acetabular liner. When different types of femoral balls and femoral stems are assembled, the flexible pressure sensor monitors the pressure applied by different types of femoral balls and femoral stems to the acetabular outer cup and the acetabular liner.

[0011] Furthermore, the extending direction of the interdigital electrodes passes through the center of the circular arc electrode, the interdigital electrodes are arranged at equal intervals along the circumference of the circular arc electrode, and one end of the interdigital electrodes is connected to the circular arc electrode;

[0012] The interdigital electrodes on the outermost arc electrode are arranged in the inner circle of the arc electrode, the interdigital electrodes on the innermost arc electrode are arranged in the outer circle of the arc electrode, and the interdigital electrodes on the middle arc electrode are arranged in both the inner circle and the outer circle of the arc electrode;

[0013] The inner circle interdigitated electrodes on the outer arc electrode are arranged in a staggered manner with the outer circle interdigitated electrodes on the adjacent inner arc electrode.

[0014] Furthermore, the same position of the plurality of arc electrodes is correspondingly connected to the lead wire, and the spacing layer further includes a triangular structure for covering the lead wire;

[0015] The spacing between adjacent arc electrodes is 5-7 mm, and the angle between two adjacent interdigital electrodes on the same arc electrode is 10°-15°; the width of the arc structure is 0.5-1 mm.

[0016] Furthermore, the flexible substrate, the spacer layer and the packaging layer are adhered together by an adhesive.

[0017] Furthermore, the flexible substrate uses TPU film, PI film or PET film as the substrate material, and the thickness of the flexible substrate is 50-60um;

[0018] The electrode layer, the spacer layer and the sensitive layer are all printed by screen printing;

[0019] Among them, the electrode layer is made of conductive silver paste or liquid metal printing, and the electrode layer is printed on a flexible substrate; the spacer layer uses insulating ink as the printing ink material and is printed by aligning the arc electrode of the electrode layer at the center of the arc electrode; the encapsulation layer also uses TPU film, PI film or PET film; the sensitive layer is printed on the encapsulation layer, and the printing material used in the sensitive layer is made of a mixture of boron nitride and ion solution 1-vinyl-3-methylimidazole nitrate; when the flexible substrate and the encapsulation layer are pasted, the sensitive layer covers the gap between the arc electrodes.

[0020] Furthermore, a layer with the same arc structure as the spacer layer is printed on the sensitive layer using TPU ink as the printing ink material as the bonding layer; the flexible substrate printed with the electrode layer and the spacer layer and the packaging layer printed with the sensitive layer and the bonding layer are aligned at the center point of the arc electrode, pasted and hot-pressed to form the final flexible pressure sensor structure.

[0021] Furthermore, the flexible pressure sensor is electrically connected to the back-end signal processing module through a flexible flat cable; the flexible front-end signal acquisition module collects the pressure signal during the hip replacement surgery and transmits the pressure signal to the back-end signal processing module; the back-end signal processing module analyzes and processes the received pressure signal to obtain pressure data, and transmits the pressure data to the host computer system; after receiving the pressure data, the host computer system analyzes it and displays it visually, and at the same time monitors in real time whether the pressure in the hip joint socket is greater than the set pressure threshold. When the set threshold is exceeded, the host computer system will alarm to prompt the doctor to replace other prostheses.

[0022] Further, the back-end signal processing module includes an AFE module and a data transmission module, the flexible pressure sensor is connected to the first switch matrix, the first switch matrix is ​​connected to the AFE module, the AFE module is connected to the data transmission module, and the data transmission module is connected to the host computer system;

[0023] The AFE module includes a second switch matrix, a voltage regulator interface, a multiplexer MUX and an AD converter, the first switch matrix is ​​connected to the voltage regulator interface, the voltage regulator interface is connected to the second switch matrix, the voltage regulator interface and the second switch matrix are both connected to the multiplexer MUX, and the multiplexer MUX is connected to the AD converter; the second switch matrix is ​​connected to the data transmission module;

[0024] The AFE module and the data transmission module are both connected to a power supply via a voltage regulator;

[0025] The signal transmitted by the flexible pressure sensor is transmitted to the AFE module through the first switch matrix, and then transmitted to the multiplexer MUX and the AD converter after being processed by the regulator interface and the second switch matrix in the AFE module. After processing, it is transmitted to the data transmission module and then transmitted to the host computer system through the data transmission module.

[0026] Furthermore, after the host computer system receives the data from the back-end signal processing module, it divides the data into multiple channels and displays them separately, which can more intuitively display the pressure distribution in the patellar fossa; and quantifies the pressure data to obtain a pressure distribution cloud map in the patellar fossa, which is then projected and transformed to simulate the pressure in the hip joint fossa during the operation in a circular area, thereby completing the visualization of the hip joint pressure during the operation.

[0027] The beneficial technical effects of the present invention are:

[0028] The flexible pressure monitoring system of the present invention makes up for the uncertainty of judging the surgical effect based on experience during hip replacement surgery, and can provide surgeons with clear pressure distribution at the hip joint during surgery, and provide objective mechanical data for the selection and adaptation of the prosthesis. At the same time, the flexible pressure monitoring system can also be used as a training tool for simulating hip replacement surgery, enriching the experience of young doctors and improving the one-time success rate of hip replacement surgery.

[0029] Specifically:

[0030] 1. The present invention takes the lack of objective measurement of force distribution in key parts such as the hip socket during hip replacement surgery as its starting point, and innovatively designs a flexible pressure monitoring system for hip replacement surgery. The flexible pressure monitoring system can realize a visual display of the pressure distribution in the hip socket during the operation, providing doctors with a visualized hip replacement surgery effect.

[0031] 2. The present invention has good flexibility and adaptability. The flexible pressure sensor is made by screen printing technology. Compared with the traditional rigid sensor, the flexible pressure sensor can conformally fit the inner surface of the acetabulum outer cup. Under the premise of not affecting the surgical effect, the pressure in the hip joint socket can be measured during the operation.

[0032] 3. The flexible pressure sensor of the present invention adopts a forked electrode structure design and has multi-channel outputs, which can measure the pressure at different positions and angles in the hip joint socket, providing a more flexible implementation solution for pressure visualization during surgery.

[0033] 4. The electrode layer of the flexible pressure sensor of the present invention adopts a structural design that combines arc electrodes and forked finger electrodes. The multiple arc electrodes are concentric and diffuse from the inside to the outside, and a dispersed design of multiple forked finger electrodes is performed around the arc electrode. This can realize pressure monitoring at different positions and angles on the spherical surface. By adjusting the dispersion density of the forked finger electrodes and the arc electrodes, more precise pressure monitoring of the spherical surface can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of the flexible pressure monitoring system of the present invention when used in hip replacement surgery;

[0035] Figure 2 It is a structural schematic diagram of a flexible pressure sensor in the flexible pressure monitoring system of the present invention;

[0036] Figure 3 It is a schematic diagram of the structure of the electrode layer in the flexible pressure sensor of the present invention;

[0037] Figure 4 This is a schematic diagram of the structure of the spacer layer in the flexible pressure sensor of the present invention;

[0038] Figure 5 It is a schematic structural diagram of the sensitive layer in the flexible pressure sensor of the present invention;

[0039] Figure 6 This is a schematic diagram of the structure of the flexible pressure sensor of the present invention when the electrode layer is printed;

[0040] Figure 7 It is a principle block diagram of the back-end signal processing module in the flexible pressure monitoring system of the present invention;

[0041] Figure 8 It is a schematic diagram of the visualization display of the host computer system in the flexible pressure monitoring system of the present invention.

[0042] In the figure: 1-flexible pressure sensor, 2-flexible flat cable, 3-back-end signal processing module, 4-acetabular cup, 5-acetabular liner, 6-femoral head, 7-femoral stem, 8-mesh, 9-hollow pattern, 10-printing ink, 11-scraper;

[0043] 101-flexible substrate, 102-electrode layer, 103-spacer layer, 104-sensitive layer, 105-encapsulation layer;

[0044] 1021-arc electrode, 1022-interdigitated electrode, 1023-lead, 1024-aligned cross center point, 1031-arc structure, 1032-triangular structure, 1041-ring structure, 1042-adhesive layer;

[0045] 301 - AFE module, 302 - programmable system-on-chip data transmission module, 303 - first switch matrix, 304 - voltage regulator, 305 - power supply;

[0046] 3011 - second switch matrix, 3012 - regulator interface, 3013 - multiplexer MUX, 3014 - AD converter. DETAILED DESCRIPTION

[0047] Currently, during total hip replacement surgery, or in the experimental stage, surgeons lack objective force data to assist with precise positioning and balance. However, solving this problem has the potential to significantly reduce the number of hip revisions due to wear, dislocation, inadequate soft tissue balance, or prosthesis impact. In addition, with the rapid development of flexible electronic technology in recent years, the development of various flexible sensors in pressure monitoring and environmental data collection has made significant progress. Compared with traditional rigid sensors, flexible sensors have been widely used in various fields due to their unique advantages such as stretchability, easy attachment, and biocompatibility.

[0048] Based on this, the present invention provides a flexible pressure monitoring system for hip replacement surgery, which includes a flexible front-end signal acquisition module, a back-end signal processing module and a host computer system. The flexible front-end signal acquisition module is a flexible pressure sensor with a sandwich structure composed of a flexible substrate, an electrode layer, a spacer layer, a sensitive layer and a top packaging layer, which is used to collect the pressure applied to the acetabular outer cup and the acetabular inner liner by different models of femoral heads and femoral stems during hip replacement surgery. The back-end signal processing module is used to receive and process the pressure data collected by the flexible front-end signal acquisition module, and transmit the pressure data to the host computer system by wire or wireless means. After the host computer system receives and analyzes the data, it realizes a visual display of the pressure in the hip replacement surgery. The flexible pressure monitoring system provides objective force data for hip replacement surgery to assist in precise positioning and balance, thereby improving the success rate of the surgery.

[0049] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0050] In conjunction with the accompanying drawings, a flexible pressure monitoring system for hip replacement surgery includes a flexible front-end signal acquisition module, a back-end signal processing module and a host computer system, wherein the flexible front-end signal acquisition module is connected to the back-end signal processing module, and the back-end signal processing module is connected to the host computer system. The flexible front-end signal acquisition module includes a flexible pressure sensor 1, such as Figure 1As shown, the flexible pressure sensor 1 is placed at the hip joint, and the flexible pressure sensor 1 is electrically connected to the back-end signal processing module 3 through a flexible flat cable 2, that is, the pressure signal collected by the flexible pressure sensor 1 is transmitted to the back-end signal processing module. After the back-end signal processing module receives the pressure signal transmitted by the flexible pressure sensor, it obtains pressure data by analyzing and processing the pressure signal, and transmits the pressure data to the host computer system in a wired or wireless manner. After the host computer system receives the pressure data transmitted by the back-end signal processing module, it realizes a visual display of the pressure data through analysis and processing, and the host computer system is equipped with a warning light. When the pressure during the operation exceeds the set threshold, the host computer system will alarm to prompt the doctor to replace the femoral head and femoral stem of appropriate models.

[0051] The flexible front-end signal acquisition module, i.e., the flexible pressure sensor, collects the pressure between the acetabular cup 4, acetabular liner 5, femoral ball head 6 and femoral stem 7 of different models selected by the doctor during the hip replacement surgery, and transmits the pressure signal during the hip replacement surgery to the back-end signal processing module through the flexible flat cable FFC. The back-end signal processing module 3 analyzes and processes the pressure signal transmitted by the flexible front-end signal acquisition module to obtain pressure data, and transmits it to the host computer system by wired or wireless means. After receiving the pressure data, the host computer system visualizes the pressure data during the operation by analyzing, and intuitively and effectively displays the pressure between the acetabular cup 4, acetabular liner 5, femoral ball head 6 and femoral stem 7 during the hip joint surgery. The host computer system can display the pressure distribution at various positions and angles in the hip joint fossa. When the monitored pressure is greater than the pressure threshold set by the doctor before the operation, the host computer system will prompt and warn the doctor, so that the doctor can replace the appropriate type of surgical instruments in time.

[0052] Specifically, the flexible pressure sensor 1 is attached between the acetabular outer cup 4 and the acetabular inner liner 5. Figure 1 As shown. After the femoral ball head 6 and the femoral stem 7 are installed and fixed, the pressure distribution at various positions and angles in the hip joint socket can be monitored. That is to say, when different types of femoral ball heads 6 and femoral stems 7 are assembled, the flexible pressure sensor 1 will monitor the pressure applied by different types of femoral ball heads 6 and femoral stems 7 to the acetabular outer cup 4 and the acetabular liner 5. During the operation, after the acetabular socket is processed with an acetabular rasp and the acetabular outer cup 4 is inserted, before the acetabular liner 5 is inserted, the flexible front-end signal acquisition module is attached to the acetabular outer cup 4, and then different types of femoral ball heads 6 and femoral stems 7 are replaced. By observing the pressure data displayed by the host computer, an intuitive display of the pressure on the patient's hip joint during hip replacement surgery can be achieved.

[0053] like Figure 2As shown, the flexible pressure sensor 1 includes a flexible substrate 101, an electrode layer 102, a spacer layer 103, a sensitive layer 104 and a packaging layer 105. The spacer layer 103 is arranged between the electrode layer 102 and the sensitive layer 104. The electrode layer 102, the spacer layer 103 and the sensitive layer 104 are all arranged between the flexible substrate 101 and the packaging layer 105 to form a sandwich structure. It can be seen that the flexible substrate 101, the electrode layer 102, the spacer layer 103, the sensitive layer 104 and the packaging layer 105 are arranged in sequence from the inside to the outside or from the bottom to the top, and the packaging layer 105 is at the outermost side. The flexible pressure sensor has excellent pressure detection capability, and the stretchability and easy adhesion of the flexible material enable it to better fit the inner surface of the acetabular liner.

[0054] like Figure 3 As shown, the electrode layer 102 includes a plurality of arc electrodes 1021 of different diameters, all of which are concentrically arranged, and interdigital electrodes 1022 are arranged around the arc electrodes 1021. Figure 4 As shown, the spacing layer 103 includes a plurality of arc structures 1031 with different diameters, which cover a plurality of arc electrodes 1021 with different diameters, thereby separating the arc electrodes from the interdigital electrodes. The sensitive layer 104 covers the area between adjacent arc electrodes 1021 .

[0055] Specifically, the extension direction of the interdigitated electrodes 1022 passes through the center of the arc electrode 1021, and the interdigitated electrodes 1022 are arranged at equal intervals along the circumference of the arc electrode 1021, and one end of the interdigitated electrodes 1022 is connected to the arc electrode 1021. The interdigitated electrodes on the outermost arc electrode are arranged in the inner circle of the arc electrode, the interdigitated electrodes on the innermost arc electrode are arranged in the outer circle of the arc electrode, and the interdigitated electrodes on the middle arc electrode are arranged in both the inner and outer circles of the arc electrode. The interdigitated electrodes on the inner circle of the outer arc electrode are arranged in an alternating manner with the interdigitated electrodes on the outer circle of the adjacent inner arc electrode. The same orientation of several arc electrodes corresponds to connection with the lead 1023, and the spacing layer 103 also includes a triangular structure 1032 for covering the lead.

[0056] More specifically, the spacing between adjacent arc electrodes 1021 is 5-7 mm, and the angle between two adjacent interdigital electrodes 1022 on the same arc electrode 1021 is 10°-15°. The width of the arc structure 1031 is 0.5-1 mm. The sensitive layer 104 can be regarded as including a plurality of circular ring structures 1041 of different diameters, and the width of the circular ring structure 1041 is 4.5-6 mm.

[0057] More preferably, a dispersed design of one interdigitated electrode every 10° and a diffusion of arc electrodes every 5 mm from the inside to the outside can realize pressure monitoring at different positions and angles on the spherical surface. By improving the dispersion density and diffusion speed of the interdigitated electrodes 1022 and the arc electrodes 1021, more precise pressure monitoring of the spherical surface can be achieved. The width of the arc structure 1031 is 0.5 mm. The arc structure 1031 avoids indirect contact between adjacent arc electrodes in the electrode layer through the sensitive layer, thereby avoiding crosstalk between electrodes. The width of the ring structure 1041 is 4.5 mm. Figure 5 As shown, the sensitive layer 104 is the part between different arc electrodes except the spacer layer. The performance change of the material printed on the sensitive layer is the key to measuring the pressure signal within the range covered by the sensitive layer. When pressure is applied, the change in pressure causes the change in resistance or capacitance of the sensitive layer material, thereby causing the change in resistance or capacitance of the sensor. There is a proportional relationship between resistance or capacitance and pressure, and the pressure signal can be indirectly measured by measuring the change in resistance or capacitance.

[0058] The electrode layer 102 is printed on one side of the flexible substrate 101, and the sensitive layer 104 is printed on one side of the encapsulation layer 105. The flexible substrate 101, the spacer layer 103 and the encapsulation layer 105 are bonded together by an adhesive.

[0059] The above-mentioned flexible substrate 101 uses a flexible material TPU film, PI film or PET film as a substrate material with a thickness of about 50um. For example, the good mechanical properties and bending resistance of the PET film material enable it to be attached to and completely covered with the inner curved surface of the acetabular outer cup 4, thereby realizing the pressure measurement of the spherical curved surface. The electrode layer 102, the spacer layer 103 and the sensitive layer 104 are all printed by screen printing, which differs from the different ink materials and hollow patterns selected during the screen printing process. Among them, the electrode layer 102 is printed using conductive silver paste or liquid metal as a printing ink material, and the electrode layer 102 is printed on the flexible substrate 101. The spacer layer 103 uses insulating ink as a printing ink material and is aligned with the arc electrode 1021 of the electrode layer 102 through the alignment cross center point 1024 designed at the center of the arc electrode, so that the spacer layer 103 covers the arc electrode 1021 to achieve the effect of spacing. The encapsulation layer 105 also uses TPU film, PI film or PET film. The sensitive layer 104 is printed on the encapsulation layer 105 . The printing material used in the sensitive layer 104 is made of a mixture of boron nitride and an ion solution 1-vinyl-3-methylimidazole nitrate. When the flexible substrate 101 and the encapsulation layer 105 are attached, the sensitive layer 104 covers the gap between the arc electrodes 1021 .

[0060] On the sensitive layer 104, TPU ink is used as the printing ink material to print a layer of arc structure that is the same as the spacer layer as the adhesive layer 1042, and the circular ring structure 1041 is formed between two adjacent adhesive layers 1042. Of course, the adhesive layer can also be further printed in the center of the sensitive layer 104 using TPU ink. The sensitive layer 104 can also be printed as a whole, and then the adhesive layer is printed, so that the sensitive layer is divided into several circular ring structures, such as Figure 5 As shown. A triangular notch is provided on the sensitive layer 104 at the position corresponding to the triangular structure 1032. The flexible substrate printed with the electrode layer and the spacer layer and the packaging layer printed with the sensitive layer and the adhesive layer are aligned and pasted at the alignment cross center point 1024 designed at the center of the arc electrode and hot pressed to form the final flexible pressure sensor structure.

[0061] The following is a further explanation of the screen printing process:

[0062] like Figure 6 As shown, firstly, a designed hollow pattern 9 is made on the mesh 8, and printing ink 10 is applied on the designed hollow pattern 9, and a base material carrying the printing pattern is placed under the printing screen. A scraper 11 is used to continuously and evenly scrape the printing ink 10 from above the hollow pattern 9 to below the hollow pattern and ensure that the printing ink 10 completely covers the hollow pattern 9, so that a thin film layer that is the same as the printing ink material and consistent with the hollow pattern 9 can be obtained on the base material.

[0063] Furthermore, the production of the sensor requires making a hollow pattern on the mesh that is the same as the electrode layer, the spacer layer, and the sensitive layer. First, use the same hollow pattern as the electrode layer, apply conductive silver paste or liquid metal on the hollow pattern to print the electrode layer 102 with conductive silver paste or liquid metal as the base material on the flexible substrate 101, and then heat and cure it at 100°C for 20 minutes. Then, using the cured electrode layer as the substrate, using the same hollow pattern as the spacer layer, using insulating ink as the printing ink material, and aligning the center point of the alignment cross designed in the center of the arc in the middle, the insulating ink is printed on the arc electrode and the lead of the electrode layer, and then heated and cured at 100°C for 20 minutes. Use the same hollow pattern as the sensitive layer on the top packaging layer to print a sensitive material made of a mixture of boron nitride and ion solution 1-vinyl-3-methylimidazole nitrate, and heat and cure it at 100°C for 15 minutes.

[0064] On the cured top encapsulation layer, with the sensitive layer as the base, the same hollow pattern as the spacer layer is used, and TPU ink is used as the printing ink material to print a layer of arc-shaped structure as the spacer layer as the bonding layer. The printed flexible substrate is aligned with the top encapsulation layer by aligning the cross center point designed at the center of the arc, and the lead wire is aligned with the soft flat cable, and the sensor is prepared by hot pressing at 90℃ for 90s.

[0065] Further, such as Figure 7 As shown, the back-end signal processing module 3 includes an AFE module 301 and a programmable system-on-chip data transmission module 302, the flexible pressure sensor 1 is connected to the first switch matrix 303, the first switch matrix 303 is connected to the AFE module 301, the AFE module 301 is connected to the programmable system-on-chip data transmission module 302, and the programmable system-on-chip data transmission module 302 is connected to the host computer system.

[0066] The AFE module 301 includes a second switch matrix 3011, a voltage regulator interface 3012, a multiplexer MUX 3013 and an AD converter 3014. The first switch matrix 303 is connected to the voltage regulator interface 3012, the voltage regulator interface 3012 is connected to the second switch matrix 3011, the voltage regulator interface 3012 and the second switch matrix 3011 are both connected to the multiplexer MUX 3013, and the multiplexer MUX 3013 is connected to the AD converter 3014. The second switch matrix 3011 is connected to the programmable system-on-chip data transmission module 302. The AFE module 301 and the programmable system-on-chip data transmission module 302 are both connected to the power supply 305 through the voltage regulator 304.

[0067] The signal transmitted by the flexible pressure sensor 1 is transmitted to the AFE module 301 through the first switch matrix 303, and is transmitted to the multiplexer MUX 3013 and the AD converter 3014 after being processed by the voltage regulator interface 3012 and the second switch matrix 3011 in the AFE module 301, and is transmitted to the programmable chip system data transmission module 302 after being processed, and is transmitted to the host computer system through the programmable chip system data transmission module 302. The multiplexer MUX can realize the display of data of different channels respectively, so as to more intuitively show the pressure distribution in the patellar fossa, and the AD converter realizes the conversion of data analog signals to digital signals, so as to facilitate subsequent data processing and analysis.

[0068] After the host computer system receives the data from the back-end signal processing module 3, it divides the data into multiple channels and displays them separately, such as Figure 8As shown, a more intuitive display of the pressure distribution in the patellar fossa is achieved. The pressure data is quantified to obtain a pressure distribution cloud map in the patellar fossa. After projection transformation, the pressure in the hip fossa during the operation is simulated in a circular area to achieve visualization of the hip joint pressure during the operation. Since the flexible pressure sensor uses interdigital electrodes and has multiple outputs, the host computer system displays the received data in real time through multiple channels, and simulates the pressure at various positions and angles in the hip fossa through processing to achieve visualization of the pressure in the hip fossa. Moreover, when the pressure in a certain area of ​​the hip fossa is greater than the pre-set pressure threshold, the warning light configured by the host computer system will light up to remind the doctor to replace the appropriate femoral head and femoral stem, thereby improving the success rate of hip replacement surgery.

[0069] The working process of the flexible pressure monitoring system is as follows: the flexible front-end signal acquisition module collects the pressure signal during the hip replacement surgery and transmits the pressure signal to the back-end signal processing module through an electrical connection. The back-end signal processing module analyzes and processes the received pressure signal to obtain pressure data, and transmits the pressure data to the host computer system by wired or wireless means. After receiving the pressure data, the host computer system analyzes it and displays it visually. At the same time, it monitors in real time whether the pressure in the hip joint socket is greater than the set pressure threshold. When it exceeds the set threshold, the host computer system will alarm and prompt the doctor to replace other prostheses. The doctor can analyze the visualized data of the host computer system to determine whether the selected prosthesis is suitable.

[0070] The parts not described in the above methods can be realized by adopting or drawing on existing technologies.

[0071] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any improvements, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible pressure monitoring system for hip replacement surgery, characterized in that: It includes a flexible front-end signal acquisition module, a back-end signal processing module and a host computer system, wherein the flexible front-end signal acquisition module is connected to the back-end signal processing module, and the back-end signal processing module is connected to the host computer system; The flexible front-end signal acquisition module includes a flexible pressure sensor, which is placed at the hip joint; The flexible pressure sensor includes a flexible substrate, an electrode layer, a spacer layer, a sensitive layer and a packaging layer, wherein the spacer layer is arranged between the electrode layer and the sensitive layer, and the electrode layer, the spacer layer and the sensitive layer are all arranged between the flexible substrate and the packaging layer to form a sandwich structure; The electrode layer includes several arc electrodes with different diameters, all of which are concentrically arranged, and interdigitated electrodes are arranged around the arc electrodes; the spacing layer includes several arc structures with different diameters, correspondingly covering several arc electrodes with different diameters; the sensitive layer covers the area between adjacent arc electrodes.

2. A flexible pressure monitoring system for hip replacement surgery according to claim 1, characterized in that: The flexible pressure sensor is attached between the acetabular outer cup and the acetabular inner liner. When different models of femoral ball heads and femoral stems are assembled, the flexible pressure sensor monitors the pressure applied by different models of femoral ball heads and femoral stems to the acetabular outer cup and the acetabular inner liner.

3. A flexible pressure monitoring system for hip replacement surgery according to claim 1, characterized in that: The extending direction of the interdigital electrodes passes through the center of the circular arc electrode, the interdigital electrodes are arranged at equal intervals along the circumference of the circular arc electrode, and one end of the interdigital electrodes is connected to the circular arc electrode; The interdigital electrodes on the outermost arc electrode are arranged in the inner circle of the arc electrode, the interdigital electrodes on the innermost arc electrode are arranged in the outer circle of the arc electrode, and the interdigital electrodes on the middle arc electrode are arranged in both the inner circle and the outer circle of the arc electrode; The inner circle interdigitated electrodes on the outer arc electrode are arranged in a staggered manner with the outer circle interdigitated electrodes on the adjacent inner arc electrode.

4. A flexible pressure monitoring system for hip replacement surgery according to claim 3, characterized in that: The same position of the plurality of arc electrodes is connected to the lead wire, and the spacing layer further comprises a triangular structure for covering the lead wire; The spacing between adjacent arc electrodes is 5-7 mm, and the angle between two adjacent interdigital electrodes on the same arc electrode is 10°-15°; the width of the arc structure is 0.5-1 mm.

5. A flexible pressure monitoring system for hip replacement surgery according to claim 1, characterized in that: The flexible substrate, the spacer layer and the encapsulation layer are bonded together by an adhesive.

6. A flexible pressure monitoring system for hip replacement surgery according to claim 1, characterized in that: The flexible substrate uses TPU film, PI film or PET film as the substrate material, and the thickness of the flexible substrate is 50-60um; The electrode layer, the spacer layer and the sensitive layer are all printed by screen printing; Among them, the electrode layer is made of conductive silver paste or liquid metal printing, and the electrode layer is printed on a flexible substrate; the spacer layer uses insulating ink as the printing ink material and is printed by aligning the arc electrode of the electrode layer at the center of the arc electrode; the encapsulation layer also uses TPU film, PI film or PET film; the sensitive layer is printed on the encapsulation layer, and the printing material used in the sensitive layer is made of a mixture of boron nitride and ion solution 1-vinyl-3-methylimidazole nitrate; when the flexible substrate and the encapsulation layer are pasted, the sensitive layer covers the gap between the arc electrodes.

7. A flexible pressure monitoring system for hip replacement surgery according to claim 6, characterized in that: A layer with the same arc structure as the spacer layer is printed on the sensitive layer using TPU ink as the printing ink material as the bonding layer; the flexible substrate printed with the electrode layer and the spacer layer and the packaging layer printed with the sensitive layer and the bonding layer are aligned at the center point of the arc electrode and pasted and hot-pressed to form the final flexible pressure sensor structure.

8. A flexible pressure monitoring system for hip replacement surgery according to claim 1, characterized in that: The flexible pressure sensor is electrically connected to the back-end signal processing module via a flexible flat cable; the flexible front-end signal acquisition module acquires pressure signals during hip replacement surgery and transmits the pressure signals to the back-end signal processing module; the back-end signal processing module analyzes and processes the received pressure signals to obtain pressure data, and transmits the pressure data to the host computer system; after receiving the pressure data, the host computer system analyzes the data and displays it visually, and at the same time monitors in real time whether the pressure in the hip joint socket is greater than the set pressure threshold. When the set threshold is exceeded, the host computer system will alarm to prompt the doctor to replace other prostheses.

9. A flexible pressure monitoring system for hip replacement surgery according to claim 8, characterized in that: The back-end signal processing module includes an AFE module and a data transmission module, the flexible pressure sensor is connected to the first switch matrix, the first switch matrix is ​​connected to the AFE module, the AFE module is connected to the data transmission module, and the data transmission module is connected to the host computer system; The AFE module includes a second switch matrix, a voltage regulator interface, a multiplexer MUX and an AD converter, the first switch matrix is ​​connected to the voltage regulator interface, the voltage regulator interface is connected to the second switch matrix, the voltage regulator interface and the second switch matrix are both connected to the multiplexer MUX, and the multiplexer MUX is connected to the AD converter; the second switch matrix is ​​connected to the data transmission module; The AFE module and the data transmission module are both connected to a power supply via a voltage regulator; The signal transmitted by the flexible pressure sensor is transmitted to the AFE module through the first switch matrix, and then transmitted to the multiplexer MUX and the AD converter after being processed by the regulator interface and the second switch matrix in the AFE module. After processing, it is transmitted to the data transmission module and then transmitted to the host computer system through the data transmission module.

10. A flexible pressure monitoring system for hip replacement surgery according to claim 8, characterized in that: After the host computer system receives the data from the back-end signal processing module, it divides the data into multiple channels and displays them separately, which can more intuitively show the pressure distribution in the patellar fossa; and quantifies the pressure data to obtain a pressure distribution cloud map in the patellar fossa. After projection transformation, it simulates the pressure in the hip joint fossa during the operation in a circular area, thereby completing the visualization of the hip joint pressure during the operation.

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