Pressure sensing system for detecting capsule contracture in real time based on friction power generation

Abstract

The invention discloses a pressure sensing system for detecting capsule contracture in real time based on friction power generation, which adopts a friction nano sensor array, is arranged in an array form, and is used for feeding back the elastic modulus change of a capsule around an implant through output voltage and identifying the capsule contracture trend in time. A negative friction layer of the sensor is made of hydrophilic monomethacrylate-terminated organosilane, a positive friction layer adopts a sandwich structure of two layers of glycidyl methacrylate modified chitosan and an electrode layer, and the whole sensor adopts a negative-positive-negative friction layer packaging structure, so that the flexibility, biocompatibility, signal stability and sensitivity in a closed environment are ensured; according to the implant capsule contracture early warning device, non-contact data storage and extraction, data transmission and remote monitoring are achieved through the integrated data transmission device, in addition, the power supply problem is solved through the friction electricity energy collection technology, battery support is not needed, the implant capsule contracture early warning device is suitable for being implanted for a long time, and an innovative solution is provided for early warning and refined monitoring of implant capsule contracture.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure sensors, and in particular to a friction-generated pressure sensing system for real-time detection of capsular contracture. Background Art

[0002] Capsular contracture is a common complication after implant surgery. The main manifestation of capsular contracture is the abnormal thickening or contraction of fibrous tissue around the implant. This change can easily cause deformation and displacement of the implant, resulting in local pain or dysfunction in the patient. At present, clinical detection of capsular contracture mainly relies on imaging methods and physical examination. Common imaging examination methods include ultrasound, magnetic resonance imaging, and computed tomography. Although these methods can provide medical personnel with specific information on capsule thickness and implant location, they have obvious limitations. First, imaging examinations cannot provide real-time and continuous data. Patients must undergo regular follow-up examinations to obtain updated test information, which lags behind in early intervention. In addition, the cost of using high-precision imaging equipment is high, which increases the economic burden on patients. Moreover, the operation of these devices requires the participation of professionals, which further limits the convenience and popularity of the test. Manual palpation is another commonly used clinical detection method, but its sensitivity is limited. It can only detect capsular contracture and hardening that has developed to the middle and late stages, and is powerless against subtle changes in early capsular contracture. Therefore, existing detection methods often fail to detect the early signs of capsular contracture in a timely manner, thus missing the best time for intervention.

[0003] The pressure sensor can convert the pressure signal into a usable output electrical signal according to a certain rule. The traditional pressure sensor indicates the pressure through the deformation of the elastic element, but this structure has the defects of large size, heavy mass, and cannot provide electrical energy output. With the advancement of implantable medical devices, taking the friction electric nano-generation technology as an example, based on the principles of friction electrification effect and electrostatic induction, it generates electricity by collecting the mechanical energy generated by people when walking or running, and realizes self-powering for cardiac pacemakers, implantable infusion pumps, implantable defibrillators, etc. Related technologies also apply friction nano-generators to pressure sensing devices. For example, CN104374498A discloses a pressure sensor and pressure sensing system based on friction power generation, in which an elastic matrix with a regular convex structure is provided, and the corresponding relationship between the contact area of ​​the friction generator and the output signal is used to make the output signal of the friction generator represent the size of the pressure, and it has the characteristics of self-powering, and can work normally without an external power supply; CN116007794A discloses a pressure sensing device based on a friction nano-generator, including a friction nano-generator, a processor and a data transmitter; the friction nano-generator is used for pressure measurement and mechanical can be converted into electrical energy, and the processor is used to process the voltage signal output by the friction nanogenerator and transmit the signal to the peripheral terminal through the data transmitter; CN116412940A discloses a pressure sensor based on friction nanogenerator power generation, the surface of at least one friction layer includes a multi-level micro-nano structure, and the multi-level structure with different heights is designed, so that the pressure sensor can maintain high sensitivity to large static forces, and the measurement range of the pressure sensor can be expanded, so that the sensor maintains the same or similar sensitivity under various static forces, and can be deployed in wearable devices for monitoring pulse fluctuations, or, deployed in electronic devices with touch screens for detecting touch actions. However, the pressure sensing devices in the above-mentioned related technologies can only detect a single parameter, such as pressure, and it is difficult to fully detect the capsular contracture phenomenon around the implant. In addition, the biocompatibility and flexibility of the friction layer material are insufficient, and it is difficult to sensitively detect subtle changes and contracture trends in the early stage of capsular contracture.

[0004] Based on this, there is an urgent need to provide a friction-generated pressure sensing system that can monitor the capsule status in real time after implantation, and can sensitively realize continuous monitoring of the entire process of capsular contracture. Summary of the invention

[0005] The purpose of the present invention is to provide a friction-generated pressure sensing system for real-time detection of capsular contracture, which can sensitively realize continuous monitoring of the entire process of implant capsular contracture.

[0006] The present invention provides a pressure sensing system based on triboelectric power generation for real-time detection of capsular contracture, comprising a triboelectric nanosensor array and a data transmission device and a power management device electrically connected to the triboelectric nanosensor array, wherein the triboelectric nanosensor array comprises a plurality of triboelectric nanosensors, which are distributed around an implant in an array and are used to detect changes in the capsule around the implant;

[0007] The friction nanosensor is composed of a negative friction layer-positive friction layer-negative friction layer structure, the positive friction layer is encapsulated in a packaging structure surrounded by the negative friction layer, the positive friction layer is composed of a sandwich structure of a first flexible biomaterial layer / electrode layer / second flexible biomaterial layer, the first flexible biomaterial layer and the second flexible biomaterial layer are composed of chitosan modified by glycidyl methacrylate, and the negative friction layer is composed of organosilane terminated with monomethacrylate;

[0008] The friction nanosensor array transmits the detected signal to the data transmission device, and the output result is transmitted to the cloud platform or an external display terminal through the data transmission device to monitor the envelope change;

[0009] The friction nanosensor array transmits the collected electrical energy to the power management device to achieve self-powering.

[0010] Optionally, the electrode layer is composed of silver nanowires.

[0011] Optionally, the thickness of the first flexible biomaterial layer and the second flexible biomaterial layer is 100-300 μm, the thickness of the electrode layer is 10-100 μm, and the thickness of the negative friction layer is 100-300 μm.

[0012] Optionally, a contact structure is formed on the contact and separation surfaces of the positive friction layer and the negative friction layer, wherein the diameter of the contact structure is 10 to 200 μm and the distribution density is 2000 to 3000 / cm 2 .

[0013] Optionally, the data transmission device includes a data processing module, a microcontroller and a data transmission module, and the data transmission module includes at least one of a Bluetooth module, a WIFI module or an NFC module; and / or,

[0014] The power management device includes a charging module and a power supply module.

[0015] Optionally, the friction nanosensor array is distributed in an m×n array, where m is the number of rows, n is the number of columns, and m and n are independently selected from integers between 5 and 30.

[0016] Optionally, a voltage comparator is integrated in the microcontroller, and the signal voltage inputted from the friction nanosensor array is compared by the voltage comparator. If it is determined that the input signal voltage is less than a preset threshold by more than m×n×10%, the data transmission module is triggered to transmit an alarm.

[0017] Optionally, the method for preparing the friction nanosensor comprises the following preparation steps:

[0018] Providing the positive friction layer comprises the following steps:

[0019] preparing the first flexible biomaterial layer;

[0020] preparing an electrode layer, wherein the electrode layer is formed on the first flexible biomaterial layer,

[0021] preparing the second flexible biomaterial layer, wherein the second flexible biomaterial layer is formed on the electrode layer, so as to obtain a positive friction layer having a sandwich structure of the first flexible biomaterial layer / electrode layer / second flexible biomaterial layer;

[0022] providing the negative friction layer;

[0023] Packaging: The provided positive friction layer and the negative friction layer are packaged according to a three-layer structure of negative friction layer-positive friction layer-negative friction layer, and the positive friction layer is packaged between the two negative friction layers.

[0024] Optionally, providing the positive friction layer comprises the following preparation steps:

[0025] The first flexible biomaterial layer is prepared by: preparing a 0.1-3.0 vol% acetic acid aqueous solution, measuring 10-50 mL of the acetic acid aqueous solution, and adding it to a container containing 0.1-3 g of chitosan to obtain a chitosan solution; adding 0.1-3 g of monomer glycidyl methacrylate to the chitosan solution and continuously stirring and reacting at 40-80° C. for 5-48 hours, and finally repeatedly washing with deionized water until neutral to obtain a modified chitosan solution; then casting the modified chitosan solution into a mold by a tape casting film forming method, and drying to obtain the first flexible biomaterial layer;

[0026] Preparing the electrode layer: coating a silver nanowire solution on the surface of the first flexible biomaterial layer, and after drying, obtaining the electrode layer deposited on the surface of the first flexible biomaterial layer;

[0027] Prepare the second flexible biomaterial layer: repeat the modified chitosan solution casting method of the first flexible biomaterial layer and cast it into a mold, and cover the electrode layer on the mold. After drying, obtain the positive friction layer of the first flexible biomaterial layer / electrode layer / second flexible biomaterial layer sandwich structure.

[0028] Optionally, providing the negative friction layer comprises the following steps: weighing single-end hydroxyl polyether silicone oil and isocyanoethyl methacrylate in a molar ratio of 0.1:1 to 1:0.1, placing 1 to 5 g of the single-end hydroxyl polyether silicone oil and 1 to 20 g of dichloromethane in a three-necked flask, dropping 0.01 to 0.5 g of dibutyltin dilaurate as a catalyst and stirring evenly, dropping the isocyanoethyl methacrylate into the three-necked flask, adjusting the temperature to 25 to 55° C., reacting for 1 to 5 hours, extracting with ether to remove the catalyst and unreacted monomers, obtaining monomethacrylate-terminated organosilane by reduced pressure distillation, pouring the organosilane into a mold, and drying to prepare the negative friction layer.

[0029] In summary, the present invention has at least one of the following beneficial effects:

[0030] 1) The present invention provides a friction-generated pressure sensing system for real-time detection of capsular contracture, which adopts a specific negative-positive-negative three-layer packaging structure, wherein the negative friction layer is composed of a monomethacrylate-terminated organosilane, and the positive friction layer is composed of a sandwich structure of a first flexible biomaterial layer / electrode layer / second flexible biomaterial layer, wherein the first flexible biomaterial layer and the second flexible biomaterial layer are composed of chitosan modified with glycidyl methacrylate, thereby ensuring the high biocompatibility, mechanical flexibility and electrical signal output performance of the system. The sensing system of the present invention can adapt to the dynamic changes of human tissues, avoid foreign body reactions or displacement, and can accurately and sensitively detect changes in signal voltage caused by changes in the elastic modulus of the capsule.

[0031] 2) The present invention provides a friction-generated pressure sensing system for real-time detection of capsular contracture. The change in elastic modulus of the capsule is detected by a friction nanosensor "Go" array. The friction nanosensor array is distributed in an m×n array, where m is the number of rows and n is the number of columns. m and n are independently selected from integers between 5 and 30. By comparing the signal voltage input by the friction nanosensor array, it is determined that the input signal voltage is less than the preset threshold by more than m×n×10%, and then the alarm transmission is triggered to achieve real-time monitoring and early warning of capsular contracture. Compared with traditional imaging examinations, the present invention can capture abnormal changes in the capsule at an earlier stage and avoid intervention after severe contracture occurs.

[0032] 3) The present invention provides a pressure sensing system based on triboelectric power generation for real-time detection of capsular contracture. The sensor array is not only used to detect changes in the elastic modulus of the capsule, but also can collect energy through the triboelectric effect, solving the power supply problem of long-term implanted devices. Compared with traditional systems that require battery replacement, the battery-free design of the present invention reduces interference to patients and improves the stability, convenience and safety of the system. In addition, the system integrates a wireless communication module. Compared with the single detection method in the prior art, the present invention can provide long-term trend data and support personalized postoperative management.

[0033] 4) The present invention provides a friction-generated pressure sensing system for real-time detection of capsular contracture, which can be widely used in the postoperative management of joint replacements, facial implants, breast prostheses and other types of implants, providing a new solution for the refined postoperative management of implants, and has broad application prospects and market value. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 . A schematic diagram of the structure of a pressure sensing system based on friction power generation according to an embodiment of the present invention;

[0035] Figure 2 . A schematic diagram of an array of friction nanosensors arranged in a Go-like manner according to an embodiment of the present invention;

[0036] Figure 3 . A schematic diagram of the structure of a friction nanosensor according to an embodiment of the present invention;

[0037] Figure 4 . A schematic diagram of the pressure-output voltage of a friction nanosensor according to an embodiment of the present invention;

[0038] Figure 5 . Schematic diagram of the detection signal voltage of the friction nanosensing system according to one embodiment of the present invention. DETAILED DESCRIPTION

[0039] In recent years, the rapid development of flexible electronic devices and friction sensing technology has brought new possibilities to the field of medical monitoring. In particular, flexible friction sensors can directly generate signals through friction charge separation, and because of their lightness and softness, they have become an ideal choice for human implantable monitoring. However, existing friction sensors have certain shortcomings in structural design and functional realization. For example, the sensitivity of the sensor and the biocompatibility of the flexible material need to be optimized, and most existing products can only detect a single parameter, such as pressure, and it is difficult to fully detect the capsular contracture around the implant. The inventors have ingeniously provided a pressure sensing system based on friction power generation for real-time detection of capsular contracture. The friction nanosensor adopts a friction nanosensor, which is composed of a unique packaging structure of negative friction layer-positive friction layer-negative friction layer. Due to the friction electrification effect, charges will accumulate on the contact surface of the positive friction layer-negative friction layer. Charge transfer occurs when the positive friction layer-negative friction layer contacts and separates to form an electrical signal. On the one hand, the data transmission device of the sensing system can be connected to the electrode to output the electrical signal to it. Due to the different development processes of capsular contracture, the elastic modulus of the capsule will change to varying degrees. Under the same force conditions, the contact between the positive friction layer and the negative friction layer of the friction nanosensor around the capsule changes, causing the electrical signal to change. By analyzing the changes in the electrical signal, the changes in the elastic modulus of the capsule can be sensitively analyzed, thereby realizing full-process monitoring of the capsule state. On the other hand, electrical energy can be output to the outside through the electrode, and the output electrical energy is connected to the power management device of the sensing system through a wire, thereby realizing self-powering of the sensing system without the need for additional power support, thereby realizing stable long-term monitoring. In addition, the friction nanosensor adopts a specific negative-positive-negative packaging structure, which can effectively increase the contact area and structural stability of the friction layer, enhance the output electrical signal, and further improve the sensitivity and reliability of the detection. The positive friction layer and the negative friction layer are composed of specific materials with obvious differences in electronegativity. While having good flexibility and biocompatibility, they can accumulate more charges during contact and separation, and have good electrical signal output performance. Therefore, the sensitivity of the detection can be further improved. The present invention is obtained on the basis of this research.

[0040] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below in conjunction with the embodiments and drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] In an embodiment of the present invention, the present invention provides a friction-generated pressure sensing system for real-time detection of capsular contracture, comprising a friction nanosensor array and a data transmission device and a power management device electrically connected to the friction nanosensor array. The friction nanosensor array comprises a plurality of friction nanosensors, which are distributed in an array around an implant and are used to detect changes in the elastic modulus of the capsule around the implant. Figure 1 FIG. 1 is a schematic diagram of the structure of a sensor system according to an embodiment of the present invention. Figure 1 As shown, the friction nanosensor array is connected to the data transmission device and the power management device through the connection circuit, respectively. The data transmission device is used to transmit the signal detected by the sensor array to the cloud platform or the external display terminal to read the state and trend data of the capsular contracture and realize real-time detection. The power management device is used to power the data transmission device, thereby realizing the self-power supply of the pressure sensing system. Exemplarily, the power management device includes but is not limited to an electrically connected charging module and a power supply module, and the charging module outputs the electric potential energy input by the sensor array to the power supply module for power supply. The data transmission device includes but is not limited to an electrically connected data processing module, a microcontroller and a data transmission module. The data processing module includes but is not limited to an analog-to-digital converter, etc. The microcontroller manages all peripheral modules to work in an orderly manner. The data transmission module includes but is not limited to a Bluetooth module, a Wi-Fi module or an NFC module, etc. After the data processing module completes the processing of the sensor array input signal, it is output to the microcontroller for the next step of data processing and storage, and finally wirelessly transmitted to the external cloud platform or display device through the data transmission module. Specifically, the input end of the charging module (such as a capacitor) of the power management device is connected to the signal output end of the friction nanosensor array, and the mechanical energy of the human body during movement is collected and converted into electrical energy by the friction nanosensor array and stored in the charging module to achieve self-power supply. In addition, the signal output end of the friction nanosensor array is connected to the data processing module (such as an analog-to-digital converter) of the data transmission device. The data processing module converts the analog electrical signal output by the friction nanosensor array into a digital electrical signal, and transmits the converted electrical signal to the connected microcontroller. The microcontroller processes the electrical signal to obtain an output result, and transmits the processed result to the data transmission module for transmission. It should be understood that the result of the sensor array detection signal after processing is not necessarily transmitted continuously. It can be stored by the microcontroller after data processing. When the detection data needs to be extracted, the data can be extracted by non-contact methods such as Bluetooth, Wi-Fi or NFC. The microcontroller sends instructions to control data transmission, and transmits the data to the cloud platform or an external display terminal for remote monitoring and analysis. The modules of the above-mentioned data transmission device and power management device use conventional components in the field, which are not described in detail here.

[0042] Figure 2 FIG. 1 is a schematic diagram of an array of friction nanosensor units arranged in a go-like pattern according to an embodiment of the present invention, as shown in FIG. Figure 2 As shown, the friction nanosensor array is distributed in an m×n array, where m is the number of rows and n is the number of columns, and m and n are independently selected from integers between 5 and 30. Figure 2 Where m and n are 6. The voltage comparator is integrated in the microcontroller, which can compare the input voltage, send instructions after finding an abnormality, and control the data transmission module to send an alarm signal. The preset threshold of the comparison can be set by software. Specifically, the signals detected by m×n friction nanosensors can be compared with the preset thresholds respectively. If the number of signals below the preset threshold is determined to be more than m×n×10%, the data transmission module is triggered to transmit an alarm to the cloud platform or an external display terminal, so as to monitor and find the early signs of capsular contracture in time.

[0043] In the embodiment of the present invention, the structural schematic diagram of the friction nanosensor unit is as follows Figure 3 As shown, the friction nanosensor includes a packaging structure of negative friction layer-positive friction layer-negative friction layer, the positive friction layer is located in the middle position, the two negative friction layers are respectively located opposite to the upper and lower sides of the positive friction layer, and the ends of the two negative friction layers located on the upper and lower sides extend toward each other and are connected to form a packaging structure.

[0044] Specifically, the positive friction layer includes a first flexible biomaterial layer / electrode layer / second flexible biomaterial layer stacked in sequence, with thicknesses of 200μm / 50μm / 200μm respectively. The first flexible biolayer and the second flexible biolayer of this embodiment are made of the same material, both of which are chitosan modified with glycidyl methacrylate. Chitosan contains amino groups that donate electrons and exhibits tribopositive properties. At the same time, chitosan has good biocompatibility and antibacterial properties. By modifying chitosan with glycidyl methacrylate, the number of tribopositively charged groups is increased, thereby increasing output performance and sensitivity. The electrode layer uses silver nanowires, the thickness of the electrode layer is 50μm, and the density of the silver nanowires is 0.5mg / cm 2 , with excellent conductivity.

[0045] In an embodiment of the present invention, Figure 3 As shown, a contact structure is formed on the first surface of the first flexible biomaterial layer and the second flexible biomaterial layer facing the negative friction layer. During the friction process, the contact area is increased to further improve the output performance. For example, the contact structure is a hemispherical protrusion with a diameter of 10 μm-200 μm and a density of 2000-3000 / cm 2 , the second surfaces of the first flexible biomaterial layer and the second flexible biomaterial layer are in contact with the electrode layer.

[0046] In an embodiment of the present invention, the negative friction layers located on the upper and lower sides of the positive friction layer are made of monomethacrylate-terminated organosilane, and the thickness of the negative friction layer is 200μm. Organosilane is tribo-negatively charged, and its electronegativity is greatly different from that of chitosan modified by glycidyl methacrylate, which is beneficial to increase the amount of friction charge transfer. Through monomethacrylate end-capping, it is beneficial to improve flexibility, output performance and stability, and realize reliable monitoring after long-term implantation. A contact structure is formed on the surface opposite to the positive friction layer. The contact structure is a hemispherical protrusion with a diameter of 10μm-200μm and a density of 2000-3000 / cm 2 , which is beneficial to increase the contact area, thereby further improving the output performance.

[0047] In an embodiment of the present invention, a sensor array includes a plurality of friction nanosensor units integrated around an implant, and an electrode layer of each sensor unit leads an electrical signal out of the packaging structure through a wire and is electrically connected to a data transmission device and a power management device respectively.

[0048] In an embodiment of the present invention, a method for preparing a friction nanosensor unit is also provided, comprising the following preparation steps:

[0049] The positive friction layer is prepared, comprising the following steps:

[0050] Preparation of the first flexible biomaterial layer: prepare 0.1-3.0 vol% acetic acid aqueous solution, measure 10-50 mL of acetic acid aqueous solution, add it to a beaker containing 0.1-3 g of chitosan (CS, Chitosan, Shanghai Maokang Biotechnology Co., Ltd.), stir at room temperature for 1-24 hours, wait until it is completely dissolved to obtain a chitosan solution, add 0.1-3 g of monomer glycidyl methacrylate (GMA, SOG-02, Shanghai Jiayirong Polymer Co., Ltd.) to the chitosan solution and continue stirring at 200 r / min for 0.5-3 hours, continue stirring and reacting in a constant temperature oil bath at 40-80°C for 5-48 hours, and finally repeatedly wash with deionized water until neutral to obtain a modified chitosan (G-CS) solution. Then, 10 to 50 mL of a modified chitosan (G-CS) solution with a concentration of 0.02 to 0.12 g / mL is cast into a polytetrafluoroethylene inverted mold having a uniform hemispherical pit structure by a film casting method. The diameter of the hemispherical pit structure is 10 to 200 μm, and the density of the pit is 2000 to 3000 / cm 2 , dried at room temperature for 2 to 48 hours, and taken out to prepare a first flexible biomaterial layer, and a hemispherical contact structure is formed on the first surface of the first flexible biomaterial layer, the contact structure is a hemispherical structure with a diameter of 10 to 200 μm, and the density of the contact structure is 2000 to 3000 / cm 2 .

[0051] Preparation of electrode layer: Silver nanowires (S980821, Shanghai McLean Biochemical Co., Ltd., China) were uniformly coated on the second surface of the first flexible biomaterial layer. The concentration of the silver nanowire solution was 10-50 mg / mL, and the coating density of the silver nanowires was 0.5-2 mg / cm 2 and dried at room temperature for 2 to 48 hours to obtain an electrode layer, which is deposited on the second surface of the first flexible biomaterial layer.

[0052] Preparation of the second flexible biomaterial layer: Repeat the same casting film forming operation as the first flexible biomaterial layer, pour 10 to 50 mL of a modified chitosan (G-CS) solution with a concentration of 0.02 to 0.12 g / mL into a polytetrafluoroethylene inverted mold with a uniform hemispherical pit structure, and then cover the electrode layer on the first flexible biomaterial layer on the upper surface of the polytetrafluoroethylene inverted mold, dry at room temperature for 2 to 48 hours, and take out to prepare the second flexible biomaterial layer, and prepare a positive friction layer with a sandwich structure of the first flexible biomaterial layer / electrode layer / second flexible biomaterial layer.

[0053] The negative friction layer is prepared, comprising the following steps: weighing single-end hydroxyl polyether silicone oil (PDMS-PEG-OH, 30674-80-7, China Shanghai McLean Biochemical Co., Ltd.) and isocyanoethyl methacrylate (IEM, 30674-80-7, China Shanghai McLean Biochemical Co., Ltd.) in a molar ratio of (0.1:1) to (1:0.1), placing 1 to 5 g of the single-end hydroxyl polyether silicone oil and 1 to 20 g of redistilled dichloromethane (DCM, D807825, China Shanghai McLean Biochemical Co., Ltd.) in a three-necked flask, dropping 0.01 to 0.5 g of dibutyltin dilaurate (DBTDL, 77-58-7, Shanghai Biochemical Co., Ltd.) as a catalyst and stirring for 10 to 30 minutes, dissolving isocyanoethyl methacrylate in dichloromethane and dropping it into the three-necked flask at a speed of 1 to 3 mL / min, adjusting the temperature to 25 to 55° C., and reacting for 1 to 5 hours. Subsequently, ether was used as an extractant to remove the catalyst and unreacted monomers. Finally, monomethacrylate-terminated organosilane (S-PDMS) was obtained by reduced pressure distillation, and the monomethacrylate-terminated organosilane was poured into a polytetrafluoroethylene reverse mold with a uniform hemispherical pit structure. The diameter of the hemispherical pit structure was 10 to 200 μm, and the density of the pits was 2000 to 3000 / cm 2 , and dried at 40-85°C for 1-12h to prepare a negative friction layer with a contact structure.

[0054] Packaging: The prepared positive friction layer and negative friction layer are assembled according to a "negative-positive-negative" sandwich structure, and the surfaces of the positive friction layer and the negative friction layer having contact structures are arranged relative to each other. The contact structures of the positive and negative friction layers can be interlocked to increase the effective contact area during contact and separation. The three-layer structure is packaged with the negative friction layer to prepare a friction nanosensor unit.

[0055] Repeating the above method of preparing the friction nanosensor unit can prepare multiple friction nanosensor units. Arrange the multiple friction nanosensor units in an array, and lead the electrode layer of each friction nanosensor unit to a wire to connect to a data transmission device and a power management device respectively, and transmit the data to a cloud platform or an external display terminal through the data transmission device to realize visual display analysis.

[0056] In a specific embodiment of the present invention, a method for preparing a friction nanosensor unit includes the following preparation steps:

[0057] First, prepare a 2% (v / v) acetic acid aqueous solution, measure 25 mL of the acetic acid aqueous solution, add it to a beaker containing 1.5 g of chitosan powder, stir at room temperature for 10 h, wait until it is completely dissolved, and prepare a chitosan solution. Add 1.5 g of monomer glycidyl methacrylate (GMA) to the chitosan solution and continue stirring for 1.5 h. Continue stirring in a constant temperature oil bath at 60 ° C for 24 h to react. Finally, wash repeatedly with deionized water until neutral to obtain a modified chitosan (G-CS) solution. Then, cast 25 mL of the modified chitosan solution with a concentration of 0.12 g / mL into a polytetrafluoroethylene inverted mold with a uniform hemispherical pit structure by a casting film method (the diameter of the pit structure is 100 μm, and the distribution density of the pit structure is 2500 / cm 2 ), dried at room temperature for 24 h, and the first flexible biomaterial layer of chitosan modified with glycidyl methacrylate was taken out, and silver nanowires were evenly coated on it (the concentration of the silver nanowire solution was 10 mg / mL, and the coating density of the silver nanowires was 0.5 mg / cm 2 ) and dried at room temperature for 24 hours to obtain an electrode layer; repeat the aforementioned modified chitosan solution casting film forming operation to prepare a second flexible biomaterial layer of chitosan modified by glycidyl methacrylate on the electrode layer, thereby preparing a sandwich structure film of "first flexible biomaterial layer / electrode layer / second flexible biomaterial layer" as the positive friction layer of the friction nanosensor unit, and its two side surfaces have a uniform contact structure, the first flexible biomaterial layer and the second flexible biomaterial layer are 200μm thick, the electrode layer is 50μm thick, the contact structure has a diameter of 100μm, and the distribution density is 2500 / cm 2 .

[0058] 2) Weigh monohydroxyl-terminated polyether silicone oil (PDMS-PEG-OH) and isocyanoethyl methacrylate (IEM) at a molar ratio of 0.5:1, place 2.5g of monohydroxyl-terminated polyether silicone oil and 5g of redistilled dichloromethane (DCM) in a three-necked flask, drop 0.2g of dibutyltin dilaurate (DBTDL) as a catalyst and stir for 20min, dissolve isocyanoethyl methacrylate (IEM) in dichloromethane (DCM) and drop into the three-necked flask at a rate of 3mL / min, adjust the temperature to 35°C, and react for 3h. Subsequently, use ether as an extractant to remove the catalyst and unreacted monomers. Finally, monomethacrylate-terminated organosilane (S-PDMS) was obtained by vacuum distillation and poured into a pre-prepared polytetrafluoroethylene mold with a uniform hemispherical pit structure (the diameter of the pit structure was 100 μm and the distribution density of the pit structure was 2500 / cm 2 ), and dried at 60°C for 6h to prepare a negative friction layer with a contact structure. The positive friction layer and the negative friction layer are assembled in a "negative-positive-negative" sandwich structure and sealed with the negative friction layer. The contact structures of the positive friction layer and the negative friction layer can be "embedded" to increase the effective contact area during contact and separation, and a friction nanosensor unit is prepared. Figure 4 : is the output voltage of the friction nanosensor prepared in this embodiment under different pressures. It can be seen that the friction nanosensor prepared in this embodiment has good electrical output performance and detection sensitivity.

[0059] 3) Lead out the silver nanowire electrode layer of the friction nanosensor unit through the lead wire, and use it as a "bridge" to "bridge" multiple friction nanosensor units to form a 10×10 "Go" array structure. The electrode layer of the sensor array is connected to the data transmission device and power management device of the sensor system through wires.

[0060] The friction nanosensor system prepared in this embodiment was placed on capsules with different contracture degrees, tested on a servo cycle tester, and a pressure of 30N was applied to each sensor unit. The sensor voltage was collected and data was processed using a digital source meter. The detection signal of the friction nanosensor system prepared in this embodiment was measured as shown in the schematic diagram. Figure 5As shown, the output voltage test graphs of no capsule formation (the number of signals below the preset threshold does not exceed m×n×10%), mild capsule (the number of signals below the preset threshold is more than m×n×10% and not more than m×n×50%), moderate capsule (the number of signals below the preset threshold is more than m×n×50% and not more than m×n×80%) and severe capsule (the number of signals below the preset threshold is more than m×n×80%) are respectively shown. It can be seen that the friction nanosensing system of this embodiment is capable of realizing real-time and sensitive detection of the state and trend of capsule contracture.

[0061] In another specific embodiment of the present invention, a method for preparing a friction nanosensor unit includes the following preparation steps:

[0062] First, prepare a 0.1% (v / v) acetic acid aqueous solution, measure 10 mL of the acetic acid aqueous solution, add it to a beaker containing 0.1 g of chitosan powder, stir at room temperature for 1 h, wait until it is completely dissolved, and prepare a chitosan solution. Add 0.1 g of monomer glycidyl methacrylate (GMA) to the chitosan solution and continue stirring at 100 r / min for 0.5 h. Continue stirring in a constant temperature oil bath at 60°C for 48 h. Finally, wash repeatedly with deionized water until neutral to obtain a modified chitosan (G-CS) solution. Then, cast 10 mL of the modified chitosan (G-CS) solution with a concentration of 0.02 g / mL into a polytetrafluoroethylene inverted mold with a uniform hemispherical pit structure by a casting film method (the diameter of the pit structure is 10 μm, and the density of the pit structure distribution is 3000 / cm 2 ), dried at room temperature for 12 h, and the first flexible biomaterial layer of chitosan modified with glycidyl methacrylate was taken out, and silver nanowires were evenly coated on it (the concentration of the silver nanowire solution was 50 mg / mL, and the coating density of the silver nanowires was 2 mg / cm 2 ) and dried at room temperature for 12 hours to obtain an electrode layer; repeat the aforementioned modified chitosan solution casting film forming operation to prepare a second flexible biomaterial layer of chitosan modified by glycidyl methacrylate on the electrode layer, thereby preparing a sandwich structure film of "first flexible biomaterial layer / electrode layer / second flexible biomaterial layer" as the positive friction layer of the friction nanosensor unit, and its two side surfaces have a uniform contact structure, the layer thickness of the first flexible biomaterial layer and the second flexible biomaterial layer is 200μm respectively, the thickness of the electrode layer is 50μm, the diameter of the contact structure is 10μm, and the distribution density is 3000 / cm 2 .

[0063] 2) Weigh monohydroxyl-terminated polyether silicone oil (PDMS-PEG-OH) and isocyanoethyl methacrylate (IEM) at a molar ratio of 0.1:1. Place 1g of monohydroxyl-terminated polyether silicone oil (PDMS-PEG-OH) and 10g of redistilled dichloromethane (DCM) in a three-necked flask, add 0.01g of dibutyltin dilaurate (DBTDL) as a catalyst and stir for 10min. Dissolve isocyanoethyl methacrylate (IEM) in dichloromethane (DCM) and drip into the three-necked flask at a rate of 2mL / min, adjust the temperature to 25°C, and react for 5h. Subsequently, use ether as an extractant to remove the catalyst and unreacted monomers. Finally, monomethacrylate-terminated organosilane (S-PDMS) was obtained by vacuum distillation and poured into a pre-prepared polytetrafluoroethylene mold with a uniform hemispherical pit structure (the diameter of the pit structure was 10 μm and the density of the pit structure distribution was 3000 / cm 2 ), and dried at 40°C for 12h to prepare a negative friction layer with a contact structure. The positive friction layer and the negative friction layer are assembled in a "negative-positive-negative" sandwich structure and sealed with the negative friction layer. The contact structures of the positive friction layer and the negative friction layer can be "embedded" to increase the effective contact area during contact and separation, and a friction nanosensor unit is prepared.

[0064] 3) Lead out the silver nanowire electrode layer of the friction nanosensor unit through the lead wire, and use it as a "bridge" to "bridge" multiple friction nanosensor units to form a 5×5 "Go" array structure. The electrode layer of the sensor array is connected to the data transmission device and power management device of the sensor system through wires.

[0065] The same method is used to detect signals using the friction nanosensor system, and the detection signals of no capsule formation, mild capsule, moderate capsule and severe capsule can still be sensitively measured.

[0066] In another specific embodiment of the present invention, a method for preparing a friction nanosensor unit includes the following preparation steps:

[0067] First, prepare a 3% (v / v) acetic acid aqueous solution, measure 50 mL of the acetic acid aqueous solution, add it to a beaker containing 3 g of chitosan powder, stir at room temperature for 24 h, wait until it is completely dissolved, and prepare a chitosan solution. Add 3 g of monomer glycidyl methacrylate (GMA) to the chitosan solution and continue stirring for 3 h. Continue stirring and reacting in a constant temperature oil bath at 80 ° C for 5 h. Finally, wash repeatedly with deionized water until neutral to obtain a modified chitosan (G-CS) solution. Then, 50 mL of the modified chitosan (G-CS) solution with a concentration of 0.12 g / mL is cast into a polytetrafluoroethylene inverted mold with a uniform hemispherical pit structure (the diameter of the pit structure is 200 μm, and the distribution density of the pit structure is 2000 / cm 2 ), dried at room temperature for 48 h, and the first flexible biomaterial layer of chitosan modified with glycidyl methacrylate was taken out, and silver nanowires were evenly coated on it (the concentration of the silver nanowire solution was 10 mg / mL, and the coating density of the silver nanowires was 0.5 mg / cm 2 ) and dried at room temperature for 48 hours to obtain an electrode layer, repeating the aforementioned modified chitosan solution casting film forming operation to prepare a second flexible biomaterial layer of chitosan modified by glycidyl methacrylate on the electrode layer, thereby preparing a sandwich structure film of "first flexible biomaterial layer / electrode layer / second flexible biomaterial layer" as the positive friction layer of the friction nanosensor unit, and its two side surfaces have a uniform contact structure, the first flexible biomaterial layer and the second flexible biomaterial layer are 200 μm thick, the electrode layer is 50 μm thick, the contact structure has a diameter of 200 μm, and the distribution density is 2000 / cm 2 .

[0068] 2) Weigh monohydroxyl-terminated polyether silicone oil (PDMS-PEG-OH) and isocyanoethyl methacrylate (IEM) at a molar ratio of 1:0.5, place 5g of monohydroxyl-terminated polyether silicone oil and 20g of redistilled dichloromethane (DCM) in a three-necked flask, drop 0.5g of dibutyltin dilaurate (DBTDL) as a catalyst and stir for 30min, dissolve isocyanoethyl methacrylate (IEM) in dichloromethane (DCM) and drop into the three-necked flask at a rate of 3mL / min, adjust the temperature to 55°C, and react for 1h. Subsequently, use ether as an extractant to remove the catalyst and unreacted monomers. Finally, monomethacrylate-terminated organosilane (S-PDMS) was obtained by vacuum distillation and poured into a pre-prepared polytetrafluoroethylene mold with a uniform hemispherical pit structure (the diameter of the pit structure was 200 μm and the distribution density of the pit structure was 2000 / cm 2), and dried at 85°C for 1h to prepare a negative friction layer with a contact structure. The positive friction layer and the negative friction layer are assembled in a "negative-positive-negative" sandwich structure and sealed with the negative friction layer. The contact structures of the positive friction layer and the negative friction layer can be "embedded" to increase the effective contact area during contact and separation, and a friction nanosensor unit is prepared.

[0069] 3) Lead out the silver nanowire electrode layer of the friction nanosensor unit through the lead wire, and use it as a "bridge" to "bridge" multiple friction nanosensor units to form a 30×30 "Go" array structure. The electrode layer of the sensor array is connected to the data transmission device and power management device of the sensor system through wires.

[0070] The same method is used to detect signals using the friction nanosensor system, and the detection signals of no capsule formation, mild capsule, moderate capsule and severe capsule can still be sensitively measured.

[0071] The present invention provides a friction-generated pressure sensing system for real-time detection of capsular contracture. During the implant surgery, a friction nanosensor array is integrated around the implant. The system automatically collects real-time data on output voltage changes caused by changes in the capsule elastic modulus, and stores the data in a data transmission device. The data transmission device uploads the data to a cloud platform (cloud) or an external display terminal (computer or mobile phone, etc.). The doctor determines the risk of capsular contracture based on the analysis results and provides a personalized intervention plan. The system is suitable for monitoring a variety of capsule conditions including joint replacement, facial implants, and breast prostheses.

[0072] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, it is possible to make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention. In addition, the above definitions of the various components and methods are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and those of ordinary skill in the art can simply change or replace them. In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to the above list, and can be changed or rearranged according to the desired design.

Claims

1. A pressure sensing system based on triboelectric power generation for real-time detection of capsular contracture, characterized in that: It includes a friction nanosensor array and a data transmission device and a power management device electrically connected to the friction nanosensor array, wherein the friction nanosensor array includes a plurality of friction nanosensors, which are distributed around the implant in an array and are used to detect changes in the capsule around the implant; The friction nanosensor is composed of a negative friction layer-positive friction layer-negative friction layer structure, the positive friction layer is encapsulated in a packaging structure surrounded by the negative friction layer, the positive friction layer is composed of a sandwich structure of a first flexible biomaterial layer / electrode layer / second flexible biomaterial layer, the first flexible biomaterial layer and the second flexible biomaterial layer are composed of chitosan modified by glycidyl methacrylate, and the negative friction layer is composed of organosilane terminated with monomethacrylate; The friction nanosensor array transmits the detected signal to the data transmission device, and the output result is transmitted to the cloud platform or an external display terminal through the data transmission device to monitor the envelope change; The friction nanosensor array transmits the collected electrical energy to the power management device to achieve self-powering.

2. A friction-generated pressure sensing system for real-time detection of capsular contracture according to claim 1, characterized in that: The electrode layer is composed of nano silver wires.

3. A friction-generated pressure sensing system for real-time detection of capsular contracture according to claim 1, characterized in that: The thickness of the first flexible biomaterial layer and the second flexible biomaterial layer is 100-300 μm, the thickness of the electrode layer is 10-100 μm, and the thickness of the negative friction layer is 100-300 μm.

4. A friction-generated pressure sensing system for real-time detection of capsular contracture according to any one of claims 1 to 3, characterized in that: A contact structure is formed on the contact and separation surfaces of the positive friction layer and the negative friction layer. The diameter of the contact structure is 10 to 200 μm, and the distribution density is 2000 to 3000 / cm 2 .

5. A friction-generated pressure sensing system for real-time detection of capsular contracture according to any one of claims 1 to 3, characterized in that: The data transmission device includes a data processing module, a microcontroller and a data transmission module, the data transmission module includes at least one of a Bluetooth module, a WIFI module or an NFC module; and / or the power management device includes a charging module and a power supply module.

6. A friction-generated pressure sensing system for real-time detection of capsular contracture according to claim 5, characterized in that: The friction nanosensor array is distributed in an m×n array, where m is the number of rows and n is the number of columns, and m and n are independently selected from integers between 5 and 30.

7. A friction-generated pressure sensing system for real-time detection of capsular contracture according to claim 6, characterized in that: The microcontroller integrates a voltage comparator, which compares the signal voltage input by the friction nanosensor array. If it is determined that the input signal voltage is less than a preset threshold by more than m×n×10%, the data transmission module is triggered to transmit an alarm.

8. A friction-generated pressure sensing system for real-time detection of capsular contracture according to any one of claims 1 to 3, characterized in that: The preparation method of the friction nanosensor comprises the following preparation steps: Providing the positive friction layer comprises the following steps: preparing the first flexible biomaterial layer; preparing an electrode layer, wherein the electrode layer is formed on the first flexible biomaterial layer, preparing the second flexible biomaterial layer, wherein the second flexible biomaterial layer is formed on the electrode layer, so as to obtain a positive friction layer having a sandwich structure of the first flexible biomaterial layer / electrode layer / second flexible biomaterial layer; providing the negative friction layer; Packaging: The provided positive friction layer and the negative friction layer are packaged according to a three-layer structure of negative friction layer-positive friction layer-negative friction layer, and the positive friction layer is packaged between the two negative friction layers.

9. A friction-generated pressure sensing system for real-time detection of capsular contracture according to claim 8, characterized in that: Providing the positive friction layer comprises the following preparation steps: The first flexible biomaterial layer is prepared by preparing a 0.1-3.0 vol% acetic acid aqueous solution, measuring 10-50 mL of the acetic acid aqueous solution, and adding it to a container containing 0.1-3 g of chitosan to prepare a chitosan solution; adding 0.1-3 g of monomer glycidyl methacrylate to the chitosan solution and continuously stirring the reaction at 40-80° C. for 5-48 hours, and finally repeatedly washing with deionized water until neutral to obtain a modified chitosan solution; Then, the modified chitosan solution is cast into a mold by a film-casting method, and dried to obtain the first flexible biomaterial layer; Preparing the electrode layer: coating a silver nanowire solution on the surface of the first flexible biomaterial layer, and after drying, obtaining the electrode layer deposited on the surface of the first flexible biomaterial layer; Prepare the second flexible biomaterial layer: repeat the modified chitosan solution casting method of the first flexible biomaterial layer and cast it into a mold, and cover the electrode layer on the mold. After drying, obtain the positive friction layer of the first flexible biomaterial layer / electrode layer / second flexible biomaterial layer sandwich structure.

10. The friction-generated pressure sensing system for real-time detection of capsular contracture according to claim 8, characterized in that: The negative friction layer is provided, comprising the following steps: weighing single-end hydroxyl polyether silicone oil and isocyanoethyl methacrylate at a molar ratio of 0.1:1 to 1:0.1, placing 1 to 5 g of the single-end hydroxyl polyether silicone oil and 1 to 20 g of dichloromethane in a three-necked flask, dripping 0.01 to 0.5 g of dibutyltin dilaurate as a catalyst and stirring evenly, dripping the isocyanoethyl methacrylate into the three-necked flask, adjusting the temperature to 25 to 55° C., reacting for 1 to 5 hours, extracting with ether to remove the catalyst and unreacted monomers, obtaining monomethacrylate-terminated organosilane by reduced pressure distillation, pouring the organosilane into a mold, and drying to prepare the negative friction layer.

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