A flexible pressure monitoring system for hip replacement surgery

Abstract

The application discloses a flexible pressure monitoring system for hip replacement surgery and belongs to the technical field of biomedical devices. 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, 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 base, an electrode layer, a spacing layer, a sensitive layer and an encapsulating layer. The flexible pressure monitoring system can compensate for the uncertainty of the surgical effect determined only by experience in the hip replacement surgery process, can provide a surgeon with a clear pressure distribution at the hip joint in the surgery process, and can provide objective mechanical data for the selection and adaptation of a prosthesis.

Description

Technical Field

[0001] This invention relates to the field of biomedical device technology, specifically to a flexible pressure monitoring system for hip replacement surgery. Background Technology

[0002] Total hip arthroplasty (THA) is currently the best treatment option for end-stage hip disease, effectively resolving hip pain and functional impairment. The biomechanical goal of THA is to achieve the correct femoral head rotation center, as well as accurate displacement and positioning of the leg length, femur, and acetabular components, thereby stabilizing the hip joint.

[0003] In total hip replacement surgery, surgeons can choose to access either the acetabulum or the femoral head, first removing damaged cartilage, 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 connects to the top of the femoral stem, connecting the femur and acetabular components together. Cup, head, and stem portions are available in different size ranges, allowing for customized implant size based on patient needs. Surgeons assess the position, stability, leg length, and soft tissue balance of the trial component by examining the syndesmotic anteversion angle. They move the hip joint through full-range joint movement, repositioning and adjusting the implant size, and continuously trial-fitting. Once the trial implant is determined to be in the correct position under appropriate soft tissue tension, it is exchanged for the final implant. Currently, during this trial phase, surgeons lack objective force data to aid in precise positioning and balance. Summary of the Invention

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

[0005] The technical solution adopted in this invention is:

[0006] 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. 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 an encapsulation layer. The spacer layer is disposed between the electrode layer and the sensitive layer. The electrode layer, the spacer layer, and the sensitive layer are all disposed between the flexible substrate and the encapsulation layer, forming a sandwich structure.

[0009] The electrode layer includes several arc electrodes of different diameters, all of which are concentrically arranged, and interdigitated electrodes are arranged around the periphery of the arc electrodes; the spacer layer includes several arc structures of different diameters, which cover the several arc electrodes of 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 inner liner. When different types of femoral heads and femoral stems are assembled, the flexible pressure sensor will monitor the pressure applied by the different types of femoral heads and femoral stems to the acetabular outer cup and the acetabular inner liner.

[0011] Furthermore, the interdigitated electrodes extend through the center of the arc electrode, and the interdigitated electrodes are arranged at equal intervals around the circumference of the arc electrode, with one end of the interdigitated electrodes connected to the arc electrode.

[0012] Interdigitated electrodes on the outermost circular arc electrode are arranged in the inner circle of the circular arc electrode, interdigitated electrodes on the innermost circular arc electrode are arranged in the outer circle of the circular arc electrode, and interdigitated electrodes on the middle circular arc electrode are arranged in both the inner and outer circles of the circular arc electrode.

[0013] The interdigitated electrodes on the inner ring of the outer arc electrode are staggered with the interdigitated electrodes on the outer ring of the adjacent inner arc electrode.

[0014] Furthermore, the same position of several arc electrodes corresponds to the connection of the lead wire, and the spacer layer also includes a triangular structure for covering the lead wire;

[0015] The spacing between adjacent arc electrodes is 5-7 mm, and the included angle between two adjacent interdigitated 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, spacer layer, and encapsulation layer are bonded together with 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, spacer layer, and sensitive layer are all printed using screen printing.

[0019] The electrode layer is made of conductive silver paste or liquid metal printing and is printed on a flexible substrate. The spacer layer is printed with insulating ink as the printing ink material and is aligned with the center of the arc electrodes of the electrode layer. The encapsulation layer is also made of TPU film, PI film or PET film. The sensitive layer is printed on the encapsulation layer. The printing material of the sensitive layer is made of boron nitride and ionic solution 1-vinyl-3-methylimidazolium nitrate. When the flexible substrate and the encapsulation layer are pasted, the sensitive layer covers the gap between the arc electrodes.

[0020] Furthermore, TPU ink is used as the printing ink material to print an arc structure identical to the spacer layer on the sensitive layer as an adhesive layer; the flexible substrate with the printed electrode layer and spacer layer and the encapsulation layer with the printed sensitive layer and adhesive layer are aligned and bonded together by the center point of the arc electrode and then 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 via a flexible flat cable; the flexible front-end signal acquisition module acquires pressure signals during the 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 it and displays it visually, while simultaneously monitoring in real time whether the pressure in the hip socket exceeds a set pressure threshold. When the set threshold is exceeded, the host computer system will issue an alarm, prompting the doctor to replace the prosthesis with another one.

[0022] Furthermore, 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, and both the voltage regulator interface and the second switch matrix are connected to the multiplexer (MUX). The multiplexer (MUX) is connected to the AD converter. The second switch matrix is ​​connected to the data transmission module.

[0024] Both the AFE module and the data transmission module are connected to the 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. In the AFE module, it is processed by the voltage regulator interface and the second switch matrix and then transmitted to the multiplexer MUX and AD converter. After processing, it is transmitted to the data transmission module and then to the host computer system.

[0026] Furthermore, after receiving the data from the backend signal processing module, the host computer system divides the data into multiple channels for separate display, which can more intuitively show the pressure distribution in the patellar fossa. The pressure data is quantified to obtain a pressure distribution cloud map in the patellar fossa. After projection and transformation, the pressure in the hip joint fossa during the operation is simulated and displayed in a circular area, thus realizing the visualization of hip joint pressure during the operation.

[0027] The beneficial technical effects of this invention are:

[0028] This invention's flexible pressure monitoring system overcomes the uncertainty of judging surgical outcomes solely based on experience during hip replacement surgery. It provides surgeons with clear pressure distribution at the hip joint during surgery, offering objective biomechanical data for prosthesis selection and fitting. Simultaneously, this flexible pressure monitoring system can also serve as a training tool for simulating hip replacement surgery, enriching the experience of younger surgeons and improving the first-time success rate of hip replacement surgeries.

[0029] Specifically:

[0030] 1. This invention addresses the lack of objective measurement of force distribution in key areas such as the hip socket during hip replacement surgery. It innovatively designs a flexible pressure monitoring system for hip replacement surgery. This flexible pressure monitoring system can visualize the pressure distribution in the hip socket during surgery, providing doctors with a visual representation of the hip replacement surgery results.

[0031] 2. This invention has good flexibility and adaptability. It uses screen printing technology to produce a flexible pressure sensor. Compared with traditional rigid sensors, the flexible pressure sensor can conformally fit the inner surface of the acetabular cup, and can measure the pressure in the hip socket during surgery without affecting the surgical effect.

[0032] 3. The flexible pressure sensor of this invention adopts an interdigital electrode structure design and has multiple outputs, which can realize the measurement of pressure at different positions and angles in the hip socket, providing a more flexible 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 interdigital electrodes. Multiple arc electrodes are concentric and diffuse from the inside out, and multiple interdigital electrodes are dispersed around the arc electrodes. This enables pressure monitoring at different positions and angles on the spherical surface. By adjusting the dispersion density of the interdigital electrodes and arc electrodes, more precise pressure monitoring on the spherical surface can be achieved. Attached Figure Description

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

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

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

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

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

[0039] Figure 6 This is a schematic diagram of the electrode layer printing process in the flexible pressure sensor of the present invention;

[0040] Figure 7 This is a schematic diagram of the back-end signal processing module in the flexible pressure monitoring system of the present invention.

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

[0042] In the diagram: 1-Flexible pressure sensor, 2-Flexible flat cable, 3-Back-end signal processing module, 4-Acetabular outer cup, 5-Acetabular inner 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-Circular arc electrode, 1022-Interdigitated electrode, 1023-Lead wire, 1024-Aligned cross center point, 1031-Circular arc structure, 1032-Triangular structure, 1041-Circular ring structure, 1042-Adhesive layer;

[0045] 301-AFE module, 302-Programmable on-chip system data transmission module, 303-First switch matrix, 304-Voltage regulator, 305-Power supply;

[0046] 3011 - Second switch matrix, 3012 - Voltage regulator interface, 3013 - Multiplexer (MUX), 3014 - AD converter. Detailed Implementation

[0047] Currently, in total hip replacement surgery, or rather in the experimental stage, surgeons lack objective force data to aid in precise positioning and balance. However, solving this problem has the potential to significantly reduce the number of hip revision surgeries due to wear, dislocation, soft tissue imbalance, or prosthesis impingement. Furthermore, with the rapid development of flexible electronics technology in recent years, significant progress has been made in the development of various flexible sensors for pressure monitoring and environmental data collection. Compared to traditional rigid sensors, flexible sensors have gained widespread application in various fields due to their unique advantages such as stretchability, ease of attachment, and biocompatibility.

[0048] Based on this, the present invention provides a flexible pressure monitoring system for hip replacement surgery. The system 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 consisting of a flexible substrate, an electrode layer, a spacer layer, a sensitive layer, and a top encapsulation layer. It is used to collect the pressure exerted by different types of femoral heads and stems on the acetabular cup and acetabular liner during hip replacement surgery. The back-end signal processing module receives and processes the pressure data collected by the flexible front-end signal acquisition module and transmits the pressure data to the host computer system via wired or wireless means. After receiving and analyzing the data, the host computer system visualizes the pressure during hip replacement surgery. This 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 with reference to the accompanying drawings and specific embodiments:

[0050] Referring to 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. 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. The flexible pressure sensor 1 is electrically connected to the back-end signal processing module 3 via a flexible flat cable 2, meaning the pressure signal collected by the flexible pressure sensor 1 is transmitted to the back-end signal processing module. After receiving the pressure signal from the flexible pressure sensor, the back-end signal processing module analyzes and processes the signal to obtain pressure data, and transmits the pressure data to the host computer system via wired or wireless means. After receiving the pressure data from the back-end signal processing module, the host computer system analyzes and processes the data to visualize it. The host computer system also has an alarm light; when the pressure during surgery exceeds a set threshold, the host computer system will alert the doctor to replace the femoral head and stem with appropriate models.

[0051] The flexible front-end signal acquisition module, also known as a flexible pressure sensor, collects the pressure between different sizes of the acetabular outer cup 4, acetabular liner 5, femoral head 6, and femoral stem 7 selected by the surgeon during hip replacement surgery. The pressure signals during the hip replacement surgery are transmitted to the back-end signal processing module via a flexible flat cable (FFC). The back-end signal processing module 3 analyzes and processes the pressure signals from the flexible front-end signal acquisition module to obtain pressure data, which is then transmitted to the host computer system via wired or wireless means. Upon receiving the pressure data, the host computer system performs visualization operations on the pressure data during the surgery, visually and effectively displaying the pressure between the acetabular outer cup 4, acetabular liner 5, femoral head 6, and femoral stem 7. The host computer system can display the pressure distribution at various positions and angles within the hip socket. When the monitored pressure exceeds the pressure threshold set by the surgeon before surgery, the host computer system will provide prompts and warnings to the surgeon, enabling the surgeon to promptly replace the surgical instruments with appropriate models.

[0052] Specifically, the flexible pressure sensor 1 is attached between the acetabular outer cup 4 and the acetabular inner liner 5, such as... Figure 1 As shown. After the femoral head 6 and femoral stem 7 are installed and fixed, the pressure distribution at various positions and angles within the hip socket can be monitored. That is, when different models of femoral heads 6 and femoral stems 7 are assembled, the flexible pressure sensor 1 monitors the pressure exerted by different models of femoral heads 6 and femoral stems 7 on the acetabular cup 4 and acetabular liner 5. During the surgery, after the acetabular socket is prepared with an acetabular reamer and the acetabular cup 4 is placed, before placing the acetabular liner 5, the flexible front-end signal acquisition module is attached to the acetabular cup 4. Then, different models of femoral heads 6 and femoral stems 7 are replaced. By observing the pressure data displayed on the host computer, a direct display of the pressure exerted on the patient's hip joint during hip replacement surgery can be achieved.

[0053] like Figure 2As shown, the aforementioned flexible pressure sensor 1 includes a flexible substrate 101, an electrode layer 102, a spacer layer 103, a sensitive layer 104, and an encapsulation layer 105. The spacer layer 103 is disposed between the electrode layer 102 and the sensitive layer 104. The electrode layer 102, spacer layer 103, and sensitive layer 104 are all disposed between the flexible substrate 101 and the encapsulation layer 105, forming a sandwich structure. This can be viewed as the flexible substrate 101, electrode layer 102, spacer layer 103, sensitive layer 104, and encapsulation layer 105 being arranged sequentially from the inside out or from the bottom up, with the encapsulation layer 105 being the outermost layer. This flexible pressure sensor has excellent pressure detection capabilities, and the stretchability and easy adhesion of the flexible material allow it to fit well onto the inner surface of the acetabular liner.

[0054] like Figure 3 As shown, the electrode layer 102 includes several arc-shaped electrodes 1021 of varying diameters. All arc-shaped electrodes 1021 are concentrically arranged, and interdigitated electrodes 1022 are arranged around the periphery of the arc-shaped electrodes 1021. Figure 4 As shown, the spacer layer 103 includes several arc structures 1031 of different diameters, which cover several arc electrodes 1021 of different diameters, thereby separating the arc electrodes from the interdigitated electrodes. The sensitive layer 104 covers the area between adjacent arc electrodes 1021.

[0055] Specifically, the interdigitated electrodes 1022 extend through the center of the arc electrode 1021, and are evenly spaced along the circumference of the arc electrode 1021. One end of each interdigitated electrode 1022 is connected to the arc electrode 1021. The interdigitated electrodes on the outermost arc electrode are arranged in the inner circle, the interdigitated electrodes on the innermost arc electrode are arranged in the outer circle, and the interdigitated electrodes on the middle arc electrode are arranged in both the inner and outer circles. The interdigitated electrodes on the inner circle of the outer arc electrode are staggered with the interdigitated electrodes on the outer circle of the adjacent inner arc electrode. The same position of several arc electrodes is connected to the lead wire 1023, and the spacer layer 103 also includes a triangular structure 1032 for covering the lead wire.

[0056] More specifically, the spacing between adjacent arc electrodes 1021 is 5-7 mm, and the included angle between two adjacent interdigitated 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 considered as including several annular structures 1041 with different diameters, and the width of the annular structure 1041 is 4.5-6 mm.

[0057] More preferably, the design of a distributed interdigital electrode every 10°, along with a 5mm layer of arc-shaped electrodes spreading outwards, enables pressure monitoring at different positions and angles on a spherical surface. By improving the dispersion density and diffusion rate of the interdigital electrodes 1022 and the arc-shaped electrodes 1021, more precise pressure monitoring of the spherical surface can be achieved. The width of the arc structure 1031 is 0.5mm. The arc structure 1031 avoids indirect contact between adjacent arc-shaped electrodes in the electrode layer through the sensitive layer, thereby preventing crosstalk between electrodes. The width of the annular structure 1041 is 4.5mm. Figure 5 As shown, the sensitive layer 104 is the portion between different arc electrodes excluding the spacer layer. The performance variation of the material printed on the sensitive layer is key to achieving pressure signal measurement within the area covered by the sensitive layer. When pressure is applied, the pressure change causes a change in the resistance or capacitance of the sensitive layer material, which in turn causes a change in the resistance or capacitance of the sensor. The resistance or capacitance has a proportional relationship with the pressure, and thus 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 with an adhesive.

[0059] The aforementioned flexible substrate 101 uses flexible TPU film, PI film, or PET film as the substrate material, with a thickness of approximately 50 μm. The excellent mechanical properties and bending resistance of PET film allow it to adhere to and completely cover the inner curved surface of the acetabular outer cup 4, enabling pressure measurement on the spherical curved surface. The electrode layer 102, spacer layer 103, and sensitive layer 104 are all screen-printed, differing depending on the ink material and the cutout pattern used in the screen printing process. Specifically, the electrode layer 102 is printed using conductive silver paste or liquid metal as the printing ink material and is printed on the flexible substrate 101. The spacer layer 103 uses insulating ink as the printing ink material and is aligned with the arc electrode 1021 of the electrode layer 102 through a cross-shaped center point 1024 designed at the center of the arc electrode, achieving the spacer layer 103 covering the arc electrode 1021 to achieve the spacing effect. 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 for the sensitive layer 104 is made of boron nitride and the ionic solution 1-vinyl-3-methylimidazolium nitrate. After the flexible substrate 101 is attached to the encapsulation layer 105, the sensitive layer 104 covers the gap between the arc-shaped electrodes 1021.

[0060] A circular arc structure, identical to the spacer layer, is printed on the sensitive layer 104 using TPU ink as the printing ink material to serve as an adhesive layer 1042. The circular ring structure 1041 is formed between two adjacent adhesive layers 1042. Alternatively, an adhesive layer can be further printed using TPU ink at the center of the sensitive layer 104. The sensitive layer 104 can also be printed as a single unit, followed by the printing of the adhesive layer, thereby dividing the sensitive layer into several circular ring structures, such as... Figure 5 As shown, a triangular notch is formed on the sensitive layer 104 at the position corresponding to the triangular structure 1032. The flexible substrate with printed electrode layer and spacer layer and the encapsulation layer with printed sensitive layer and adhesive layer are aligned and bonded together by the alignment cross center point 1024 designed at the center of the arc electrode and then hot-pressed to form the final flexible pressure sensor structure.

[0061] The screen printing process will be explained in further detail below:

[0062] like Figure 6 As shown, firstly, the designed stencil pattern 9 is created on the screen 8. Then, printing ink 10 is applied over the stencil pattern 9, and a substrate material to support the printing pattern is placed under the printing screen. Using a squeegee 11, the printing ink 10 is continuously and evenly scraped from above the stencil pattern 9 to below it, ensuring that the printing ink 10 completely covers the stencil pattern 9. This results in a thin film layer on the substrate material that is the same as the printing ink material and consistent with the stencil pattern 9.

[0063] Furthermore, the sensor fabrication requires creating a perforated pattern on the mesh that is identical to that of the electrode layer, spacer layer, and sensitive layer. First, using the same perforated pattern as the electrode layer, conductive silver paste or liquid metal is applied over the perforated pattern to print the electrode layer 102, which uses conductive silver paste or liquid metal as its substrate, onto the flexible substrate 101. This is then cured at 100°C for 20 minutes. Next, using the cured electrode layer as a base, the same perforated pattern as the spacer layer is used, employing insulating ink as the printing ink material. The ink is aligned using a crosshair designed at the center of the arc, and printed onto the arc electrodes and leads of the electrode layer. This is then cured at 100°C for 20 minutes. Finally, on the top encapsulation layer, the same perforated pattern as the sensitive layer is used to print a sensitive material made from a mixture of boron nitride and the ionic solution 1-vinyl-3-methylimidazolium nitrate. This is then cured at 100°C for 15 minutes.

[0064] On the cured top encapsulation layer, using the sensitive layer as a base, and employing the same perforated pattern as the spacer layer, a circular arc-shaped structure identical to the spacer layer is printed using TPU ink as the printing ink material as an adhesive layer. The printed flexible substrate is aligned with the top encapsulation layer by using an alignment cross-shaped center point designed at the center of the arc, while simultaneously aligning the lead wires with the flexible flat cable. The sensor is then fabricated by hot-pressing at 90°C for 90 seconds.

[0065] Furthermore, such as Figure 7 As shown, the back-end signal processing module 3 includes an AFE module 301 and a programmable on-chip system 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 on-chip system data transmission module 302, and the programmable on-chip system 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, which is connected to the second switch matrix 3011. Both the voltage regulator interface 3012 and the second switch matrix 3011 are connected to the multiplexer MUX 3013, which is connected to the AD converter 3014. The second switch matrix 3011 is connected to the programmable on-chip data transmission module 302. Both the AFE module 301 and the programmable on-chip data transmission module 302 are connected to the power supply 305 via a voltage regulator 304.

[0067] The signal transmitted by the flexible pressure sensor 1 is transmitted to the AFE module 301 via the first switch matrix 303. In the AFE module 301, it is processed by the voltage regulator interface 3012 and the second switch matrix 3011 before being transmitted to the multiplexer MUX 3013 and the AD converter 3014. After further processing, the signal is transmitted to the programmable on-chip data transmission module 302, and then to the host computer system. The multiplexer MUX can display data from different channels separately, thus providing a more intuitive view of the pressure distribution within the patellar fossa. The AD converter converts the analog signal to a digital signal, facilitating subsequent data processing and analysis.

[0068] After receiving the data from the backend signal processing module 3, the host computer system divides the data into multiple channels for separate display, such as... Figure 8As shown, this provides a more intuitive display of the pressure distribution within the patellar fossa. The pressure data is quantified to obtain a pressure distribution cloud map within the patellar fossa. After projection and transformation, this map simulates the pressure experienced within the hip joint fossa during surgery within a circular area, achieving visualization of hip joint pressure during the procedure. Because 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. Simultaneously, it processes the data to simulate the pressure experienced at various positions and angles within the hip joint fossa, achieving visualization of the pressure within the patellar fossa. Furthermore, when the pressure in a certain area within the hip joint fossa exceeds a pre-set pressure threshold, a warning light configured in the host computer system illuminates, reminding the surgeon to replace the femoral head and stem with appropriate replacements, thereby improving the success rate of hip replacement surgery.

[0069] The flexible pressure monitoring system operates as follows: The flexible front-end signal acquisition module collects pressure signals during hip replacement surgery and transmits these signals to the back-end signal processing module via an electrical connection. The back-end signal processing module analyzes and processes the received pressure signals to obtain pressure data, which is then transmitted to the host computer system via wired or wireless means. Upon receiving the pressure data, the host computer system analyzes it and displays the data visually. Simultaneously, it monitors in real-time whether the pressure within the hip socket exceeds a set pressure threshold. If the threshold is exceeded, the host computer system issues an alarm, prompting the surgeon to replace the prosthesis with another option. The surgeon can analyze the visualized data from the host computer system to determine if the selected prosthesis is suitable.

[0070] For any parts not mentioned above, existing technologies can be adopted or referenced.

[0071] Finally, it should be noted that the above description 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 within 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. 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 an encapsulation layer. The spacer layer is disposed between the electrode layer and the sensitive layer. The electrode layer, the spacer layer, and the sensitive layer are all disposed between the flexible substrate and the encapsulation layer, forming a sandwich structure. The electrode layer includes several arc electrodes of different diameters, all of which are concentrically arranged, and interdigitated electrodes are arranged around the periphery of the arc electrodes; the spacer layer includes several arc structures of different diameters, which cover the several arc electrodes of different diameters; the sensitive layer covers the area between adjacent arc electrodes. The interdigitated electrodes extend through the center of the arc electrode, and are arranged at equal intervals around the circumference of the arc electrode. One end of the interdigitated electrodes is connected to the arc electrode. Interdigitated electrodes on the outermost circular arc electrode are arranged in the inner circle of the circular arc electrode, interdigitated electrodes on the innermost circular arc electrode are arranged in the outer circle of the circular arc electrode, and interdigitated electrodes on the middle circular arc electrode are arranged in both the inner and outer circles of the circular arc electrode. The interdigitated electrodes on the inner ring of the outer arc electrode are staggered with the interdigitated electrodes on the outer ring of the adjacent inner arc electrode. The same position of each of the several arc electrodes corresponds to the connection of the lead wire, and the spacer layer also includes a triangular structure for covering the lead wire; The spacing between adjacent arc electrodes is 5-7 mm, and the included angle between two adjacent interdigitated electrodes on the same arc electrode is 10°-15°; the width of the arc structure is 0.5-1 mm. The flexible pressure sensor is attached between the acetabular outer cup and the acetabular inner liner. When different types of femoral heads and femoral stems are assembled, the flexible pressure sensor will monitor the pressure applied by the different types of femoral heads and femoral stems to the acetabular outer cup and acetabular inner liner.

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

3. The 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 50-60μm; The electrode layer, spacer layer, and sensitive layer are all printed using screen printing. The electrode layer is made of conductive silver paste or liquid metal printing and is printed on a flexible substrate. The spacer layer is printed with insulating ink as the printing ink material and is aligned with the center of the arc electrodes of the electrode layer. The encapsulation layer is also made of TPU film, PI film or PET film. The sensitive layer is printed on the encapsulation layer. The printing material of the sensitive layer is made of boron nitride and ionic solution 1-vinyl-3-methylimidazolium nitrate. When the flexible substrate and the encapsulation layer are pasted, the sensitive layer covers the gap between the arc electrodes.

4. The flexible pressure monitoring system for hip replacement surgery according to claim 3, characterized in that: A circular arc structure identical to the spacer layer is printed on the sensitive layer using TPU ink as the printing ink material to serve as an adhesive layer. The flexible substrate with the printed electrode layer and spacer layer and the encapsulation layer with the printed sensitive layer and adhesive layer are aligned and bonded together by the center point of the circular arc electrode and then hot-pressed to form the final flexible pressure sensor structure.

5. 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 these 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, which is then transmitted to the host computer system. Upon receiving the pressure data, the host computer system analyzes it and displays it visually. Simultaneously, it monitors in real time whether the pressure within the hip socket exceeds a set pressure threshold. If the pressure exceeds the set threshold, the host computer system will issue an alarm, prompting the doctor to replace the prosthesis with another one.

6. A flexible pressure monitoring system for hip replacement surgery according to claim 5, 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, and both the voltage regulator interface and the second switch matrix are connected to the multiplexer (MUX). The multiplexer (MUX) is connected to the AD converter. The second switch matrix is ​​connected to the data transmission module. Both the AFE module and the data transmission module are connected to the 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. In the AFE module, it is processed by the voltage regulator interface and the second switch matrix and then transmitted to the multiplexer MUX and AD converter. After processing, it is transmitted to the data transmission module and then to the host computer system.

7. A flexible pressure monitoring system for hip replacement surgery according to claim 5, characterized in that: After receiving the data from the backend signal processing module, the host computer system divides the data into multiple channels for display, which can more intuitively show the pressure distribution in the hip socket. The system also quantifies the pressure data to obtain a pressure distribution cloud map in the hip socket. After projection and transformation, the pressure in the hip socket during the operation is simulated and displayed in a circular area, thus realizing the visualization of hip joint pressure during the operation.

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