Degradable fiber electrode fabric for three-dimensional electrogastrogram monitoring and method of making the same

Abstract

The application discloses a degradable fiber electrode fabric for three-dimensional electrogastrography monitoring and a preparation method thereof. The preparation method comprises the following steps: subjecting degradable polyglycolide fibers to plasma treatment, and evaporating a gold layer on the polyglycolide fibers; in-situ polymerizing a polypyrrole conversion layer on the surface of the gold layer; in-situ reducing gold nanoparticles on the surface of the polypyrrole conversion layer; coating a poly(1,8-octyleneglycol citrate) solution on the surface of the gold nanoparticle layer to form an insulation layer, and obtaining a degradable flexible fiber electrode; using a knitting technology to synchronously knit the flexible fiber electrode and the polyglycolide fibers to form a three-dimensional flexible fabric structure, removing the insulation layer on a target area of the flexible fabric structure to expose a conductive layer, and obtaining the degradable fiber electrode fabric. The fiber electrode fabric prepared by the application can realize full-curve fitting of a gastric serosal surface, does not need external fixation, and can be used for long-term, stable and real-time multi-dimensional gastric electrophysiological signal acquisition.

Description

Technical Field

[0001] This invention relates to the field of flexible fiber electrode technology, specifically to a biodegradable fiber electrode fabric for three-dimensional gastric electrogram monitoring and its preparation method. Background Technology

[0002] Gastrointestinal electrophysiology, as a method for assessing intestinal motility, evaluates gastrointestinal neuromuscular function by recording and analyzing electrical activities such as slow waves and spike potentials. Given the close correlation between gastric electrical activity and gastric motility, monitoring postoperative gastric electrical changes can not only provide early warning of postoperative gastroparesis but also better guide individualized treatment (such as the timing of electrical stimulation), which is of great value in improving postoperative outcomes.

[0003] Currently, techniques for monitoring gastrointestinal electrophysiology include surface electrogastrography (EGG) and intraluminal EGG, such as conventional EGG, high-resolution EGG, intraluminal electrode recording, and wireless capsule monitoring. Conventional EGG uses surface electrodes for measurement; while non-invasive and easy to operate, the signal is easily interfered with by respiration, electrocardiogram (ECG), and body movement, resulting in low accuracy. High-resolution EGG, while an improvement over conventional EGG, still suffers from interference due to surface electrodes and limited spatial resolution. Furthermore, both conventional and high-resolution EGG, being surface recordings, cannot achieve precise localization, whereas intraluminal electrode recording and wireless capsule monitoring solve this problem, achieving accurate spatial localization. However, intraluminal electrodes are invasive, easily causing mucosal damage, leading to poor patient tolerance and limiting long-term monitoring. Wireless capsule technology enables dynamic monitoring of the entire gastrointestinal tract, but it is costly, involves complex data analysis, and cannot fix monitoring sites; patients after gastrointestinal surgery cannot orally administer the capsule device. Therefore, traditional electrodes struggle to achieve long-term stable signal acquisition and precise stimulation.

[0004] With the development of sensing electrodes, flexible linear electrode arrays and patch rectangular electrode arrays for the body surface and linear electrode strips for the cavity have been reported. However, the stomach is a three-dimensional organ, and both the surface electrode array and the intragastric electrode strip have insufficient spatial resolution and cannot adapt to the dynamic deformation of the organ, which cannot meet the needs of real-time electrophysiological monitoring with three-dimensional (3D) full stomach coverage. Summary of the Invention

[0005] The purpose of this invention is to provide a three-dimensional biodegradable fiber electrode fabric that can conform to and wrap the gastric serous membrane and a method for preparing the same, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides a method for preparing a biodegradable fiber electrode fabric for three-dimensional gastric electrography monitoring, comprising the following steps:

[0007] Step S10: Plasma treatment is performed on biodegradable polyglycolic acid fibers, and a gold layer is deposited on the surface of the plasma-treated polyglycolic acid fibers to prepare gold / polyglycolic acid fibers; Step S20: Polypyrrole transduction layer is polymerized in situ on the gold layer surface of the gold / polyglycolic acid fibers to prepare polypyrrole / gold / polyglycolic acid fibers; Step S30: Gold nanoparticles are reduced in situ on the surface of the polypyrrole transduction layer of the polypyrrole / gold / polyglycolic acid fibers to prepare gold nanoparticle / polypyrrole / gold / polyglycolic acid fibers; Step S40: Poly(1,8-octanediol citrate) solution is coated on the surface of the gold nanoparticle layer of the gold nanoparticle / polypyrrole / gold / polyglycolic acid fibers. An insulating layer is formed to prepare a biodegradable flexible fiber electrode; Step S50: The flexible fiber electrode and polyglycolic acid fiber are simultaneously woven into a three-dimensional flexible fabric structure using knitting technology, and the insulating layer of the target area on the flexible fabric structure is removed to expose the conductive layer, thereby obtaining the biodegradable fiber electrode fabric. The target area includes multiple first areas and multiple second areas. Multiple signal acquisition windows formed by removing the insulating layers of multiple first areas are used as a distributed electrode array to acquire gastric electrical signals. Multiple connection interfaces formed by removing the insulating layers of multiple second areas are used for electrical connection with external electrophysiological recording equipment. The multiple connection interfaces correspond one-to-one with the multiple signal acquisition windows.

[0008] In one specific embodiment, the polyglycolic acid fiber in step S10 is pretreated polyglycolic acid fiber. The pretreatment steps of the polyglycolic acid fiber include ultrasonic cleaning with acetone as the cleaning agent, ultrasonic cleaning with anhydrous ethanol as the cleaning agent, rinsing with deionized water, and vacuum drying in sequence. The method of plasma treatment of the pretreated polyglycolic acid fiber includes plasma treatment at a power of 50W for 5 minutes in a mixed gas composed of O2 and Ar.

[0009] In one specific embodiment, the gold layer thickness is 40~80nm, and the process parameters for depositing the gold layer on the surface of the plasma-treated polyglycolic acid fiber include: a deposition rate of 0.3~0.5Å / s and a deposition time of 1500~2500s.

[0010] In one specific embodiment, the thickness of the polypyrrole transducer layer is 50~150μm. The step of in-situ polymerization of the polypyrrole transducer layer on the gold-plated surface of the gold / polyglycolic acid fiber includes: first, mixing a pyrrole aqueous dispersion and a potassium nitrate solution evenly to obtain an immersion solution; then, immersing the gold / polyglycolic acid fiber in the immersion solution until the polyglycolic acid fiber in the gold / polyglycolic acid fiber is fully impregnated; and then, polymerizing the polypyrrole transducer layer on the gold-plated surface of the impregnated gold / polyglycolic acid fiber using a chemical oxidative polymerization method or an electrochemical method. The chemical oxidative polymerization method involves: adding a ferric chloride solution dropwise to the gold / polyglycolic acid fiber impregnated with the fiber under ice bath and shaking conditions. The reaction is carried out in the immersion solution of the ester fiber. After the reaction is completed, the gold / polyglycolic acid fiber loaded with polypyrrole is taken out and cleaned of impurities to prepare polypyrrole / gold / polyglycolic acid fiber. The electrochemical method is as follows: the gold / polyglycolic acid fiber is electrically connected to the copper foil wire and placed in an electrolytic cell containing a mixed solution of pyrrole and potassium nitrate. A first three-electrode system is used, and a constant potential method is adopted. A potential of +0.7V is applied relative to the reference electrode of the first three-electrode system and maintained for 120~300s. After being taken out and cleaned, polypyrrole / gold / polyglycolic acid fiber is prepared. The first three-electrode system uses gold / polyglycolic acid fiber as the working electrode, calomel electrode as the reference electrode, and platinum wire as the counter electrode.

[0011] In one specific embodiment, the thickness of the gold nanoparticle layer is 50-100 nm. Step S30 involves in-situ reduction of the gold nanoparticles on the surface of the polypyrrole transducer layer of the polypyrrole / gold / polyglycolic acid fiber using either electroreduction or chemical reduction. The electroreduction method includes: first, immersing the polypyrrole / gold / polyglycolic acid fiber in a hydrochloric acid solution to activate the surface; then, electrically connecting the polypyrrole / gold / polyglycolic acid fiber to a copper foil wire, and finally placing it in an electrolytic cell of tetrachloroauric acid solution. Using a second and third electrode system and a constant potential method, a potential of -0.2V is applied relative to the reference electrode of the second and third electrode system, maintained for 6 seconds, and then removed. After cleaning, the gold nanoparticles are obtained. The process involves preparing gold nanoparticles / polypyrrole / gold / polyglycolic acid fibers. The second and third electrode system uses polypyrrole / gold / polyglycolic acid fibers as the working electrode, a silver / silver chloride electrode as the reference electrode, and a platinum wire electrode as the counter electrode. The chemical reduction method includes: first, placing the polypyrrole / gold / polyglycolic acid fibers in a reaction tank containing deionized water to fully impregnate the polyglycolic acid fibers; then, adding sodium formate solution and tetrachloroauric acid solution to the reaction tank to react until the reaction is complete; and finally, after cleaning, preparing gold nanoparticles / polypyrrole / gold / polyglycolic acid fibers.

[0012] In one specific embodiment, step S40 includes: Step A, mixing the solute poly(1,8-octanediol-citrate) and the solvent dichloromethane at a preset mass ratio, stirring continuously at 40~50°C for 2~4h until the solution is completely clear and transparent, to prepare a poly(1,8-octanediol-citrate) solution, wherein the molecular weight of poly(1,8-octanediol-citrate) is 15~20 kDa, and the preset mass ratio of poly(1,8-octanediol-citrate) to dichloromethane is 1:1~2; Step B, coating the poly(1,8-octanediol-citrate) solution onto the surface of the gold nanoparticle layer of gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber, removing the solvent dichloromethane by room temperature standing and vacuum drying, forming an insulating layer on the gold nanoparticle layer of gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber, to prepare a biodegradable flexible fiber electrode.

[0013] In one specific embodiment, the biodegradable fiber electrode fabric includes a main body for wrapping the gastric serosal surface and a plurality of connecting fiber electrodes extending from the main body. The connecting fiber electrodes include a connecting end connected to the main body and an end opposite to the connecting end. A plurality of signal acquisition windows are disposed on the main body, and a plurality of connection interfaces are disposed at the ends of the plurality of connecting fiber electrodes that correspond to the plurality of signal acquisition windows.

[0014] In one specific embodiment, the step of simultaneously weaving the flexible fiber electrode and polyglycolic acid fiber to form a three-dimensional flexible fabric structure using knitting technology includes: rolling the flexible fiber electrode and polyglycolic acid fiber into a roller respectively; obtaining the dimensions of the fabric structure to be woven, and using the dimensions of the fabric structure to be woven as the basis for knitting modeling; using polyglycolic acid fiber as the structural thread and the flexible fiber electrode as the conductive thread, and using knitting technology to weave a three-dimensional flexible fabric structure based on the knitting modeling basis, wherein the knitting technology includes: using double-strand knitting for odd-numbered rows and single-strand knitting for even-numbered rows, the double-strand knitting being woven from the flexible fiber electrode and the polyglycolic acid fiber, and the single-strand knitting using the flexible fiber electrode, and simultaneously, extending the movement trajectory of the flexible fiber electrode at the edge position during single-strand knitting to form the connecting fiber electrode.

[0015] In one specific embodiment, the insulating layer is 10~20μm thick. Laser engraving technology is used to remove the insulating layer in the target area to form multiple signal acquisition windows and multiple connection interfaces. The laser engraving technology includes: adopting a layered removal strategy, setting the removal depth to 2μm per pass, performing 5~10 rounds of engraving, with an adjacent scanning path spacing of 10μm, and timely removing slag by nitrogen-assisted purging.

[0016] According to a second aspect of the present invention, the present invention provides a biodegradable fiber electrode fabric for three-dimensional electrogastrography monitoring, the fiber electrode fabric being prepared by the preparation method described above.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] I. This invention provides a method for preparing a biodegradable fiber electrode fabric for three-dimensional electrogastrography monitoring, comprising the following steps: Step S10, subjecting biodegradable polyglycolic acid (PEG) fibers to plasma treatment, and depositing a gold layer on the surface of the plasma-treated PEG fibers to prepare gold / PEG fibers; Step S20, in-situ polymerizing a polypyrrole transconducting layer on the gold layer surface of the gold / PEG fibers to prepare polypyrrole / gold / PEG fibers; Step S30, in-situ reducing gold nanoparticles on the surface of the polypyrrole transconducting layer of the polypyrrole / gold / PEG fibers to prepare gold nanoparticle / polypyrrole / gold / PEG fibers; Step S40, coating a poly(1,8-octanediol citrate) solution onto the surface of the gold nanoparticle layer of the gold nanoparticle / polypyrrole / gold / PEG fibers to form an insulating layer, thereby preparing a biodegradable flexible fiber electrode; Step S50 The flexible fiber electrode and polyethylene glycol fiber are simultaneously woven into a three-dimensional flexible fabric structure using knitting technology. The insulating layer of the target area on the flexible fabric structure is removed to expose the conductive layer, resulting in the biodegradable fiber electrode fabric. On the one hand, the materials used to prepare the fiber electrode fabric in this invention are all biodegradable, avoiding secondary trauma caused by surgical removal of the device. On the other hand, the fiber electrode fabric prepared by the method of this invention can achieve full-curvature conformation to the gastric serosa without external fixation. Furthermore, the fabric can maintain close conformation to the dynamic curvature of the stomach (such as the greater curvature and lesser curvature) under gastrointestinal peristalsis or respiratory movements, achieving dynamic self-adaptation to gastric deformation. This allows for long-term, stable, and real-time multidimensional gastric electrophysiological signal acquisition. It can also dynamically select electrical stimulation sites based on real-time electrophysiological characteristics to optimize the accuracy of electrical stimulation and achieve closed-loop regulation of "monitoring-feedback-treatment".

[0019] Second, the fiber electrode fabric prepared by this invention has a porous mesh structure with good air permeability and water permeability, allowing oxygen, water and metabolites to pass through freely, thereby maintaining the normal interaction between the tissue and the external interstitial fluid and avoiding local tissue ischemia and hypoxia or inflammation caused by electrode coverage.

[0020] Third, the fiber electrode fabric prepared by this invention can restore the physiological synchronization of gastric electrical rhythm by applying electrical stimulation while monitoring, thereby fundamentally improving gastric motility disorders.

[0021] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention. In the drawings:

[0023] Figure 1 This is a schematic flowchart of a method for preparing a biodegradable fiber electrode fabric for three-dimensional gastric electrography monitoring, provided in an embodiment of the present invention.

[0024] Figure 2 The electrical properties of the single flexible fiber electrode prepared in Example 3 are shown.

[0025] Figure 3 The mechanical properties of the fiber electrode fabric prepared in Example 4 are compared with those of the unwoven flexible fiber electrode, the plain knitted fiber electrode fabric, and the 2×1 rib knitted fiber electrode fabric.

[0026] Figure 4 The electrical response diagrams of the fiber electrode fabric and platinum wire electrode prepared in Example 4 are shown.

[0027] Figure 5 This is a schematic diagram of fixing a fiber electrode fabric to the surface of the stomach, wherein, Figure 5 (a) in the diagram is a schematic of the stomach after abdominal surgery. Figure 5 (b) is a schematic diagram of a fiber electrode fabric implanted on the surface of the stomach;

[0028] Figure 6 This is a photograph of the surface of a mouse stomach after abdominal surgery, showing the fiber electrode fabric prepared in Example 4 implanted into the abdominal cavity.

[0029] Figure 7 The electrical properties of the fiber electrode fabric prepared in Example 4 degrade over time.

[0030] Figure 8 The main results of blood routine tests were measured in control mice and implantation group mice 6 weeks after surgery. Figure 8 (a) shows the white blood cell (WBC) counts in the control group and the implantation group mice. Figure 8 (b) shows the red blood cell (RBC) counts in the control group and the implantation group mice. Figure 8 (c) represents the hemoglobin concentration (HGB) of the control group mice and the implantation group mice.

[0031] Figure 9The results show the liver function test results of control mice and implantation group mice 6 weeks after surgery. Figure 9 (a) shows the alanine aminotransferase (ALT) levels in the control group and the implantation group mice. Figure 9 (b) in the figure shows the detection results of aspartate aminotransferase (ALT);

[0032] Figure 10 The results show the renal function of mice in the control and implantation groups 6 weeks after surgery. Figure 10 (a) shows the blood urea nitrogen (BUN) levels in the control group and the implantation group mice. Figure 10 (b) shows the serum creatinine (CREA) levels in the control group mice and the implantation group mice;

[0033] Figure 11 This is a diagram showing the in vivo monitoring and treatment effects of the electrode fabric corresponding to Example 4. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings.

[0035] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Polyglycolic acid fiber was purchased from Shanghai Pudong Jinhuan Medical Supplies Co., Ltd.

[0036] Please see Figure 1 In a first aspect, the present invention provides a method for preparing a biodegradable fiber electrode fabric for three-dimensional gastric electrography monitoring, comprising the following steps:

[0037] Step S10: The biodegradable polyglycolic acid fiber is subjected to plasma treatment, and a gold layer is deposited on the surface of the plasma-treated polyglycolic acid fiber to prepare gold / polyglycolic acid fiber.

[0038] In one alternative embodiment, the diameter of the polyglycolic acid fiber is 50~200μm.

[0039] In an optional embodiment, the polyglycolic acid fiber in step S10 is a pretreated polyglycolic acid fiber. The pretreatment steps of the polyglycolic acid fiber include ultrasonic cleaning with acetone as the cleaning agent, ultrasonic cleaning with anhydrous ethanol as the cleaning agent, rinsing with deionized water, and vacuum drying in sequence.

[0040] The pretreatment of the polyglycolic acid fiber is as follows: the polyglycolic acid fiber is immersed in acetone and ultrasonically cleaned for 10 min (power 100W, frequency 40kHz, temperature: 25±2℃), then transferred to anhydrous ethanol and ultrasonically cleaned for 5 min (power 100W, frequency 40kHz, temperature: 25±2℃) to remove organic residues, then rinsed with deionized water 3 times, and vacuum dried at 60℃ for 2 h.

[0041] In one optional embodiment, the method for plasma treatment of the pretreated polyglycolic acid fiber includes: plasma treatment at a power of 50W for 5 minutes in a mixture of O2 and Ar gas, wherein the volume ratio of O2 to Ar in the O2 and Ar gas mixture is 1:1.

[0042] This invention utilizes plasma treatment of polyglycolic acid fibers to increase surface polar groups (-COOH, -OH) and improve the adhesion of the gold layer.

[0043] In one alternative embodiment, the gold layer thickness is 40~80 nm.

[0044] The gold layer thickness is 40-80 nm. At this thickness, the gold layer can form a complete and continuous film with unobstructed electron transport paths. Simultaneously, a "nanoscale rough structure" naturally forms on the surface, which can serve as an "anchor point" for subsequent in-situ polymerization of polypyrrole. If the thickness is < 40 nm, gold atoms are difficult to form a continuous coverage on the surface of the polyglycolic acid fiber, easily agglomerating into "nano islands," resulting in a "discontinuous conductive path" in the metal layer. Furthermore, the low surface roughness of the gold layer means that the polypyrrole is only bound by van der Waals forces, making it easy to peel off. If the thickness is > 80 nm, the rigidity of the gold layer will significantly increase, leading to a decrease in fiber flexibility. During weaving, the gold layer is prone to cracking, or "interlayer delamination" may occur due to dynamic deformation during gastric serosa adhesion. In this case, a "dense and smooth film" easily forms on the gold layer surface, similarly reducing the interfacial bonding force with polypyrrole.

[0045] In one optional embodiment, the process parameters for depositing a gold layer on the surface of the plasma-treated polyglycolic acid fiber include: a deposition rate of 0.3~0.5 Å / s and a deposition time of 1500~2500 s.

[0046] In this invention, a gold layer is thermally deposited on the surface of polyglycolic acid fiber using a vacuum evaporation system.

[0047] Step S20: Polypyrrole transduction layer is polymerized in situ on the gold layer surface of the gold / polyglycolic acid fiber to prepare polypyrrole / gold / polyglycolic acid fiber.

[0048] In one alternative embodiment, the thickness of the polypyrrole transducer layer is 50~150 μm.

[0049] The thickness of the polypyrrole transducer layer is 50-150 μm. At this thickness, the polypyrrole layer can completely cover the surface of the gold plating layer, forming a "large-area, low-resistance contact," ensuring that the signal captured by the polypyrrole is efficiently transmitted to the gold plating layer. Furthermore, the porous structure formed by the polypyrrole at this thickness provides sufficient loading sites for the subsequent gold nanoparticles. If the thickness is <50 μm, the coverage of the gold layer is uneven, the contact area is drastically reduced, and the signal will be severely lost at the interface. Additionally, the capacity of the porous structure is limited, resulting in a sharp decrease in the loading capacity of the gold nanoparticles. If the thickness is >150 μm, the resistance of the polypyrrole itself increases, which will offset the high conductivity advantage of the gold plating layer. Moreover, the porous structure is too deep, and the gold nanoparticles can only be loaded on the surface, leading to a non-uniformity of "excessive conductivity on the surface and insufficient conductivity in the deeper layers."

[0050] In an optional embodiment, the step of in-situ polymerization of the polypyrrole transconducting layer on the gold-plated surface of the gold / polyglycolic acid fiber includes:

[0051] Step (a): First, mix the pyrrole aqueous dispersion and potassium nitrate solution evenly to obtain an soaking solution. Then, soak the gold / polyglycolic acid fiber in the soaking solution until the polyglycolic acid fiber in the gold / polyglycolic acid fiber is fully impregnated.

[0052] In one alternative embodiment, a soaking solution is obtained by mixing a pyrrole aqueous dispersion and a potassium nitrate solution in a molar ratio of 1:1.

[0053] In this invention, the molar concentration of the pyrrole aqueous dispersion is 0.17 mol / L, the molar concentration of the potassium nitrate solution is 0.17 mol / L, and the pyrrole aqueous dispersion and potassium nitrate solution are mixed at a volume ratio of 1:1 to obtain the soaking solution.

[0054] Step (b): Polymerize a polypyrrole transconducting layer on the gold layer surface of the impregnated gold / polyglycolic acid fiber using a chemical oxidative polymerization method. The chemical oxidative polymerization method is as follows: ferric chloride solution is added dropwise to the impregnation solution containing the gold / polyglycolic acid fiber under ice bath and shaking conditions. After the reaction is completed, the gold / polyglycolic acid fiber loaded with polypyrrole is taken out, and after cleaning off impurities, polypyrrole / gold / polyglycolic acid fiber is obtained.

[0055] In this invention, the shaking of the shaker and the maintenance of the ice bath during the chemical oxidative polymerization reaction are to reduce the reaction rate and obtain smaller diameter and finer polypyrrole spheres.

[0056] In one optional embodiment, the reaction time of the chemical oxidative polymerization method is 1-2 hours.

[0057] It should be noted that the reaction time is started from the point after the ferric chloride solution has been titrated.

[0058] In this invention, the process of cleaning impurities is as follows: after taking out the gold / polyglycolic acid fiber loaded with polypyrrole, carefully remove excess polypyrrole, thoroughly rinse the fiber with deionized water, and soak it in deionized water overnight (12 h) to remove excess and unreacted ferric chloride.

[0059] In one alternative embodiment, the molar ratio of the pyrrole to the ferric chloride is 34:23.

[0060] In this invention, the molar concentration of the ferric chloride solution is 0.23 mol / L.

[0061] In another alternative embodiment, the step of in-situ polymerization of the polypyrrole transconducting layer on the gold-plated surface of the gold / polyglycolic acid fiber includes:

[0062] Step (a): First, mix the pyrrole aqueous dispersion and potassium nitrate solution evenly to obtain an soaking solution. Then, soak the gold / polyglycolic acid fiber in the soaking solution until the polyglycolic acid fiber in the gold / polyglycolic acid fiber is fully impregnated.

[0063] In one alternative embodiment, a soaking solution is obtained by mixing a pyrrole aqueous dispersion and a potassium nitrate solution in a molar ratio of 1:1.

[0064] In one optional embodiment, the pyrrole aqueous dispersion has a molar concentration of 0.17 mol / L, the potassium nitrate solution has a molar concentration of 0.17 mol / L, and the pyrrole aqueous dispersion and potassium nitrate solution are mixed at a volume ratio of 1:1 to obtain an soaking solution.

[0065] Step (b): Polymerize a polypyrrole transconducting layer on the gold layer surface of the impregnated gold / polyglycolic acid fiber using an electrochemical method. The electrochemical method includes: electrically connecting the gold / polyglycolic acid fiber to a copper foil wire, placing it in an electrolytic cell containing a mixed solution of pyrrole and potassium nitrate, using a first three-electrode system, and applying a potential of +0.7V relative to the reference electrode of the first three-electrode system using a constant potential method, maintaining it for 120~300s, then removing it, and cleaning it to prepare polypyrrole / gold / polyglycolic acid fiber. In the first three-electrode system, the gold / polyglycolic acid fiber is used as the working electrode, the calomel electrode is used as the reference electrode, and the platinum wire is used as the counter electrode.

[0066] In this invention, in the first three-electrode system, the platinum wire is used as the counter electrode to increase the specific surface area of ​​the counter electrode.

[0067] Step S30: In situ reduction of gold nanoparticles on the surface of the polypyrrole transduction layer of the polypyrrole / gold / polyglycolic acid fiber to prepare gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber.

[0068] In one alternative embodiment, the thickness of the gold nanoparticle layer is 50-100 nm.

[0069] The thickness of the gold nanoparticle layer is 50-100 nm. At this thickness, the gold nanoparticles can form a "closely packed continuous network," exhibiting excellent conductivity, and the moderate thickness results in low internal stress. If the thickness is <50 nm, the nanoparticle packing density is insufficient, and gaps easily exist between the particles, leading to the breakage of the conductive pathway. If the thickness is >100 nm, the internal stress generated by the particle packing exceeds the substrate's bearing limit, making the coating prone to "microcracks," and the thick coating reduces the substrate's flexibility.

[0070] In one alternative embodiment, gold nanoparticles are in situ reduced on the surface of the polypyrrole transducing layer of the polypyrrole / gold / polyglycolic acid fiber using an electroreduction method.

[0071] The electroreduction method includes: first, immersing the polypyrrole / gold / polyglycolic acid fiber in hydrochloric acid solution to activate the surface; then, electrically connecting the polypyrrole / gold / polyglycolic acid fiber to a copper foil wire, and then placing it in an electrolytic cell of tetrachloroauric acid solution. Using a second and third electrode system, a constant potential method is employed, applying a potential of -0.2V relative to the reference electrode of the second and third electrode system, maintaining it for 6 seconds, and then removing it. After cleaning, gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber are prepared. In the second and third electrode system, polypyrrole / gold / polyglycolic acid fiber is used as the working electrode, a silver / silver chloride electrode is used as the reference electrode, and a platinum wire electrode is used as the counter electrode.

[0072] In this invention, the platinum wire in the second three-electrode system is used as the counter electrode to increase the specific surface area of ​​the counter electrode.

[0073] In one optional embodiment, the molar concentration of the hydrochloric acid solution is 0.1 mol / L, and the molar concentration of the tetrachloroauric acid solution is 1.5 mmol / L.

[0074] In one optional embodiment, the polypyrrole / gold / polyglycolic acid fiber is activated by immersing it in a hydrochloric acid solution for 5 minutes.

[0075] In another alternative embodiment, gold nanoparticles are in situ reduced on the surface of the polypyrrole transducing layer of the polypyrrole / gold / polyglycolic acid fiber using a chemical reduction method.

[0076] The chemical reduction method includes: first, placing the polypyrrole / gold / polyglycolic acid fiber in a reaction tank with deionized water to fully impregnate the polyglycolic acid fiber in the polypyrrole / gold / polyglycolic acid fiber; then, adding sodium formate solution and tetrachloroauric acid solution to the reaction tank to react until the reaction is complete; after cleaning, gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber is prepared.

[0077] Specifically: Deionized water was added to the reaction tank, and polypyrrole / gold / polyglycolic acid fibers were placed in to fully impregnate them; then, 0.25M sodium formate solution and 100mM tetrachloroauric acid solution were added to the reaction tank, mixed thoroughly, and reacted for 2 hours, wherein the volume ratio of sodium formate solution to tetrachloroauric acid solution was 40:1; subsequently, the fibers were removed and soaked in deionized water overnight (12 hours) to remove excess reactants, thus preparing gold nanoparticles / polypyrrole / gold / polyglycolic acid fibers.

[0078] Step S40: Coat the surface of the gold nanoparticle layer of the gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber with a poly(1,8-octanediol citrate) solution to form an insulating layer, thereby preparing a biodegradable flexible fiber electrode.

[0079] In one alternative embodiment, the insulating layer is 10~20 μm thick.

[0080] In one optional implementation, step S40 includes:

[0081] Step A: Mix the solute poly(1,8-octanediol-citrate) and the solvent dichloromethane according to a preset mass ratio, and stir continuously at 40~50°C for 2~4h until the solution is completely clear and transparent to prepare a poly(1,8-octanediol-citrate) solution, wherein the molecular weight of poly(1,8-octanediol-citrate) is 15~20 kDa, and the preset mass ratio is 1:1.

[0082] Step B: The poly(1,8-octanediol-citrate) solution is coated onto the surface of the gold nanoparticle layer of gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber. The solvent dichloromethane is removed by standing at room temperature and vacuum drying to form an insulating layer on the gold nanoparticle layer of gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber, thus preparing a biodegradable flexible fiber electrode.

[0083] The specific preparation process for coating a uniform poly(1,8-octanediol-citrate) insulating layer onto the surface of gold nanoparticles is as follows: Poly(1,8-octanediol-citrate) particles (molecular weight 15~20 kDa) are placed in a vacuum drying oven at 40℃ for 24 hours to dehydrate. Then, poly(1,8-octanediol-citrate) and dichloromethane are weighed at a 1:1 mass ratio. The mixture is then gently heated (40~50°C) in a fume hood using a magnetic stirrer (500~1000 rpm) and continuously stirred for 2~4 hours until the solution is completely clear and transparent. The 50wt% poly(1,8-octanediol-citrate) solution prepared above is coated onto gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber. The coated gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber is left to stand at room temperature in a fume hood for 1 hour to evaporate the solvent. Then, it is transferred to a vacuum drying oven and dried at 40℃ for 24 hours to completely remove the solvent, forming an insulating layer on the fiber surface.

[0084] In this invention, the insulating layer can be understood as an encapsulation film used to encapsulate the conductive layer.

[0085] In this invention, the gold layer, the polypyrrole transducer layer, and the gold nanoparticle layer together constitute the conductive layer.

[0086] Step S50: Using knitting technology, the flexible fiber electrode and polyglycolic acid fiber are simultaneously woven to form a three-dimensional flexible fabric structure. The insulating layer of the target area on the flexible fabric structure is removed to expose the conductive layer, thereby obtaining the biodegradable fiber electrode fabric. The target area includes multiple first areas and multiple second areas. Multiple signal acquisition windows formed by removing the insulating layers of multiple first areas are used as a distributed electrode array to acquire gastric electrical signals. Multiple connection interfaces formed by removing the insulating layers of multiple second areas are used for electrical connection with external electrophysiological recording equipment. Each of the multiple connection interfaces corresponds to one of the multiple signal acquisition windows.

[0087] In one optional embodiment, the biodegradable fiber electrode fabric includes a main body for conforming to and wrapping the gastric serous membrane and a plurality of connecting fiber electrodes extending from the main body. The connecting fiber electrodes include a connecting end connected to the main body and an end opposite to the connecting end. A plurality of signal acquisition windows are disposed on the main body, and a plurality of connection interfaces are disposed at the ends of the plurality of connecting fiber electrodes that correspond to the plurality of signal acquisition windows.

[0088] It is understandable that the connection interface is formed by removing the insulating layer at the end of the connecting fiber electrode.

[0089] In this invention, the connection interface is electrically connected to an external electrophysiological recording device via a ribbon cable, thereby enabling the distributed electrode array to collect and output gastric electrical signals.

[0090] In one optional implementation, the multiple signal acquisition windows are arranged in 3 rows × 4 columns, each signal acquisition window is 1 × 1 mm in size, the center spacing is 3~4 mm, and a 20 μm safety boundary is reserved on all four sides of each window to prevent damage to the conductive fibers.

[0091] In one optional embodiment, the step of simultaneously weaving the flexible fiber electrode and polyethylene glycol fiber into a three-dimensional flexible fabric structure using knitting technology includes:

[0092] Step (1): Roll the flexible fiber electrode and the polyglycolic acid fiber into a shaft respectively.

[0093] The specific preparation process of winding the flexible fiber electrode and the polyglycolic acid fiber into a shaft in step (1) is as follows: the winding tension of the flexible fiber electrode is set to 0.5~1.0cN, the polyglycolic acid fiber to 2~3cN, the winding speed is set to 50m / min, the winding angle is set to 15° for cross-winding, the spacing between adjacent turns is controlled to 0.2~0.3mm, and the length of each roll is controlled to 20±5m. After winding, the shaft is placed in a moisture-proof packaging for storage.

[0094] Step (2): Obtain the dimensions of the fabric structure to be woven based on the dimensions of the stomach to be monitored, and use the dimensions of the fabric structure to be woven as the basis for knitting modeling.

[0095] Using the dimensions of the fabric structure to be woven as the basis for knitting modeling is to ensure that the three-dimensional flexible fabric structure woven in the next step matches the dimensions of the stomach to be monitored.

[0096] Step (3): Using polyglycolic acid fiber as the structural wire and flexible fiber electrode as the conductive wire, based on the knitting model, a three-dimensional flexible fabric structure is woven using knitting technology. The knitting technology includes: double-strand knitting for odd-numbered rows and single-strand knitting for even-numbered rows. Double-strand knitting is woven by flexible fiber electrode and polyglycolic acid fiber. Single-strand knitting is woven using flexible fiber electrode. At the same time, during single-strand knitting, the moving trajectory of flexible fiber electrode is extended at the edge position to form the connecting fiber electrode.

[0097] In one optional embodiment, the knitting technology process parameters include: using 1×1 rib knitting with a knitting density of 10~30 stitches / cm², so that the transverse and longitudinal Young's modulus of the fabric is small, and it has good elasticity and morphological stability.

[0098] During the specific weaving process, the tension can be adjusted according to the size of different parts of the stomach, so that the three-dimensional flexible fabric structure can be woven to fit the stomach better. The adjustment of tension is based on the experience of those skilled in the art.

[0099] In this invention, each even-numbered row extends the movement trajectory of the flexible fiber electrode at its edge to form the connecting fiber electrode. Assuming a total of 100 rows, 50 rows will have connecting fiber electrodes. However, only the connecting fiber electrodes corresponding to the signal acquisition window will have a connection interface. If a signal acquisition window is formed by removing the insulating layer of the flexible fiber electrode in row 6, then the connecting fiber electrode corresponding to that signal acquisition window will be formed by extending the flexible fiber electrode in row 6, and the end of the connecting fiber electrode in row 6 will expose a conductive layer to form a connection interface. If a signal acquisition window is formed by removing the insulating layer of the flexible fiber electrode in row 12, then the connecting fiber electrode corresponding to that signal acquisition window will be formed by extending the flexible fiber electrode in row 12, and the end of the connecting fiber electrode in row 12 will expose a conductive layer to form a connection interface.

[0100] Preferably, before using knitting technology to weave the flexible fabric structure, a knitting lubricant is brushed onto the flexible fiber electrode to reduce the friction between fibers and between fibers and the machine during the knitting process, and to protect the coating from damage during the knitting process.

[0101] In one optional implementation, laser engraving technology is used to remove the insulating layer of the target area to form multiple signal acquisition windows and multiple connection interfaces. The laser engraving technology includes: adopting a layered removal strategy, setting the removal depth to 2μm for each pass, performing 5 to 10 cycles of engraving, with an adjacent scanning path spacing of 10μm, and timely removing slag by nitrogen-assisted purging.

[0102] In this invention, the laser engraving exposure signal acquisition window is specifically as follows: the prepared flexible fabric structure is fixed on a three-dimensional laser processing platform, and a vacuum adsorption stage is used to keep the sample flat and wrinkle-free (adsorption pressure -80kPa). A 355nm wavelength ultraviolet laser is selected for the laser system, equipped with a 100mm focal length flat-field lens. The processing path is generated using pre-imported three-dimensional gastric model data. The laser power is set to 8W (corresponding to an energy density of 3.2J / cm²), the pulse frequency to 30kHz, and the scanning speed to 800mm / s. A galvanometer scanning method is used to achieve precise positioning. Focal length calibration is performed before processing. A confocal displacement sensor is used to ensure that the laser focus is located on the upper surface of the poly(1,8-octanediol-citrate) layer (Z-axis positioning accuracy ±1μm), and 5×5 point surface height mapping compensation is performed in the edge region (sampling interval 2mm). In actual engraving, a layered removal strategy was adopted, with each pass having a removal depth of 2μm, and a total of 5 rounds of engraving were performed (total engraving time approximately 45 s / window). The spacing between adjacent scanning paths was 10μm, and nitrogen-assisted purging (flow rate 15L / min) was used to promptly remove slag. The signal acquisition window array was arranged in 3 rows × 4 columns, with each window measuring 1×1mm and a center-to-center spacing of 3~4mm. A 20μm safety boundary was reserved on all four sides of each window to prevent damage to the conductive fibers. The heat-affected zone was monitored in real time during the engraving process, and an infrared thermal imager was used to ensure that the local temperature did not exceed 80℃ (sampling rate 10Hz). When the temperature exceeded the limit, a 0.5 s cooling interval was automatically inserted.

[0103] The method of laser engraving exposed connection interfaces is the same as the method of laser engraving exposed signal acquisition windows, and will not be described again here.

[0104] In one optional embodiment, before removing the insulating layer of the target area using laser engraving technology, the woven flexible fabric structure is further cleaned and dried. Specifically, the prepared flexible fabric structure is immersed in anhydrous ethanol for ultrasonic cleaning for 10 min (power 100W, frequency 40kHz, temperature: 25±2℃), then rinsed three times with deionized water, and dried in an oven at 60℃~80℃ for 30~60 min.

[0105] Secondly, the present invention also provides a biodegradable fiber electrode fabric for three-dimensional electrogastrography monitoring, wherein the fiber electrode fabric is prepared by the preparation method described above.

[0106] Thirdly, the present invention also provides the application of biodegradable fiber electrode fabric in gastric electrophysiological signal acquisition and / or electrical stimulation therapy, including: acquiring multidimensional gastric electrical signals through a distributed electrode array of fiber electrode fabric and obtaining signal characteristics in real time; dynamically selecting the optimal electrical stimulation site based on the signal characteristics; and realizing closed-loop regulation of "monitoring-feedback-treatment".

[0107] Example 1

[0108] Fabrication of biodegradable flexible fiber electrodes

[0109] Step 1.1: Pre-clean and dry the polyethylene glycol (PEG) fibers and perform plasma treatment. Immerse PEG fibers with a diameter of 100 μm in acetone and ultrasonically clean for 10 min (power 100 W, frequency 40 kHz, temperature: 25 ± 2 ℃). Then transfer them to anhydrous ethanol and ultrasonically clean for 5 min to remove organic residues. Rinse three times with deionized water and vacuum dry at 60 ℃ for 2 h. After drying, treat the PEG fibers with plasma at 50 W power for 5 min in a mixed gas of O2 and Ar (volume ratio 1:1) to increase the surface polar groups (-COOH, -OH) and improve the adhesion of the gold layer.

[0110] Step 1.2: A gold layer is deposited on the surface of polyglycolic acid fiber to prepare gold / polyglycolic acid fiber. A gold layer is thermally deposited on the surface of polyglycolic acid fiber using a vacuum evaporation system at a deposition rate of 0.3 Å / s, a deposition time of 2500 s, and a gold layer thickness of 80 nm to prepare gold / polyglycolic acid fiber.

[0111] Step 1.3: Polypyrrole transduction layer is polymerized in situ on the gold-plated surface of gold / polyglycolic acid fiber to prepare polypyrrole / gold / polyglycolic acid fiber.

[0112] Step 1.3.1: Prepare a 0.17 M pyrrole aqueous dispersion and a 0.17 M potassium nitrate aqueous solution. Mix 10 mL of pyrrole aqueous dispersion and 10 mL of potassium nitrate aqueous solution at a molar ratio of 1:1 and sonicate for 30 min to fully disperse the pyrrole monomers to obtain the soaking solution.

[0113] Step 1.3.2: Immerse the prepared gold / polyglycolic acid fiber in the soaking solution for 1 hour to allow the soaking solution to fully wet the polyglycolic acid fiber.

[0114] Step 1.3.3: Dissolve ferric chloride hexahydrate in water to prepare a 0.23M ferric chloride solution. Add 5 mL of ferric chloride solution dropwise to the above-mentioned solution impregnated with gold / polyglycolic acid fiber under ice bath conditions. Shake the incubator during the reaction and maintain the ice bath to reduce the reaction rate, so as to obtain smaller diameter and finer polypyrrole spheres.

[0115] Steps 1, 3, and 4: After titration, react for another 1.5 h to remove the gold / polyglycolic acid fiber loaded with polypyrrole, carefully remove excess polypyrrole, and thoroughly rinse the polyglycolic acid fiber with deionized water. Soak in deionized water overnight (12 h) to remove excess and unreacted ferric chloride, thus preparing polypyrrole / gold / polyglycolic acid fiber with a transduction layer thickness of 100 μm.

[0116] Step 1.4: In-situ reduction of gold nanoparticles on the surface of the polypyrrole transduction layer to prepare gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber.

[0117] Step 1.4.1: Prepare 0.1M HCl solution and 1.5 mM tetrachloroauric acid solution.

[0118] Step 1.4.2: Immerse the polypyrrole / gold / polyglycolic acid fiber in 0.1M HCl solution for 5 minutes to activate the surface.

[0119] Step 1.4.3: After bonding the polyglycolic acid fiber in the polypyrrole / gold / polyglycolic acid fiber to the copper foil wire with conductive silver paste, place it in an electrolytic cell containing 1.5mM tetrachloroauric acid solution. Use a three-electrode system and a constant potential method. Apply a potential of -0.2V relative to the reference electrode and maintain it for 6s before removing it. In the three-electrode system, the polypyrrole / gold / polyglycolic acid fiber is used as the working electrode, the silver / silver chloride electrode is used as the reference electrode, and the platinum wire electrode is used as the counter electrode to increase the specific surface area of ​​the counter electrode.

[0120] Step 1.4.4: After removing the polypyrrole / gold / polyglycolic acid fiber loaded with gold nanoparticles, rinse it with deionized water to prepare gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber. The thickness of the gold nanoparticle layer is 50~100nm.

[0121] Step 1.5: Coat the surface of gold nanoparticles with a uniform poly(1,8-octanediol-citrate) insulating layer to prepare a biodegradable flexible fiber electrode.

[0122] Specifically: Poly(1,8-octanediol-citrate) particles (molecular weight 15~20kDa) were placed in a vacuum drying oven at 40℃ for 24h to dehydrate. Then, poly(1,8-octanediol-citrate) and dichloromethane were weighed at a 1:1 mass ratio, and the mixture was heated to 45°C in a fume hood and continuously stirred with a magnetic stirrer (500rpm) for 4h until the solution was completely clear and transparent. The 50wt% poly(1,8-octanediol-citrate) solution prepared above was coated onto gold nanoparticles / polypyrrole / gold / polyglycolic acid fibers. The coated fibers were left to stand at room temperature in a fume hood for 1h to evaporate the solvent, and then transferred to a vacuum drying oven at 40℃ for 24h to completely remove the solvent, forming an insulating layer (encapsulation film) on the fiber surface. The insulating layer was 10~20μm thick, thus preparing a biodegradable flexible fiber electrode.

[0123] To test the electrochemical performance of the flexible fiber electrode, a three-electrode method was employed using an electrochemical workstation. The flexible fiber electrode served as the working electrode, the silver / silver chloride electrode as the reference electrode, and the platinum wire electrode as the counter electrode. 1×PBS solution was used as the electrolyte. Impedance measurements were performed within the range of 1–100,000 Hz. Cyclic voltammetry was performed with a scan voltage range of -0.8 V to +0.8 V and a scan rate of 0.05 V / s. The impedance of each individual electrode was recorded. Figure 2 As shown.

[0124] from Figure 2 It can be seen that the flexible fiber electrode exhibits low impedance in the frequency range of 100~105 Hz. Near 1kHz, where the bioelectric signal emission frequency is concentrated, the impedance of the flexible fiber electrode is 1542Ω, indicating that the flexible fiber electrode can effectively receive bioelectric signal information.

[0125] It should be noted that the flexible fiber electrode in this embodiment is prepared using a self-made small continuous process device, which includes a syringe needle, a peristaltic pump, etc.

[0126] Example 2

[0127] Preparation of biodegradable fiber electrode fabric

[0128] Step 2.1: Weaving the electrode fabric. The prepared fiber electrode and polyethylene glycol (PEG) fiber are wound into a spool using a winding machine. A knitting lubricant is brushed onto the fiber electrode. Using PEG fiber as the structural thread and the fiber electrode as the conductive thread, a computerized flat knitting machine is used for double-strand weft knitting. The knitting program is adjusted so that the fiber electrode is knitted individually in even-numbered rows, and the movement trajectory of the fiber electrode is extended at the edge positions. The extra extended fiber electrode portion is used for connection to external devices. The knitted fabric is then immersed in anhydrous ethanol for ultrasonic cleaning for 10 min (power 100W, frequency 40kHz, temperature: 25±2℃), then rinsed three times with deionized water, and dried in a 60℃ oven for 60 min to obtain the electrode fabric. The knitting process parameters include: 1×1 rib knitting with a knitting density of 10~30 stitches / cm².

[0129] Step 2.2: Laser Engraving Exposure Signal Acquisition Window and Connection Interface. The prepared electrode fabric was fixed to a three-dimensional laser processing platform, and a vacuum adsorption stage was used to keep the sample flat and wrinkle-free (adsorption pressure -80kPa). A 355nm wavelength ultraviolet laser was selected for the laser system, equipped with a 100mm focal length flat lens. The processing path was generated using pre-imported three-dimensional stomach model data. The laser power was set to 8W (corresponding to an energy density of 3.2J / cm²), the pulse frequency to 30kHz, and the scanning speed to 800mm / s. A galvanometer scanning method was used for precise positioning. Focal length calibration was performed before processing, and a confocal displacement sensor was used to ensure the laser focus was located on the upper surface of the insulating layer (Z-axis positioning accuracy ±1μm). Surface height mapping compensation was performed at 5×5 points in the edge area (sampling interval 2mm). During actual engraving, a layered removal strategy was adopted, with a removal depth of 2μm per pass, for a total of 5 cycles of engraving (total engraving time approximately 45s / window). The spacing between adjacent scanning paths was 10μm, and nitrogen-assisted purging (flow rate 15L / min) was used to promptly remove slag. The signal acquisition window array is arranged in 3 rows × 4 columns, with each window measuring 1 × 1 mm and a center-to-center spacing of 3-4 mm. A 20 μm safety boundary is reserved on all four sides of each window to prevent damage to the conductive fibers. During the engraving process, the heat-affected zone is monitored in real time, and an infrared thermal imager is used to ensure that the local temperature does not exceed 80℃ (sampling rate 10Hz). When the temperature exceeds the limit, a 0.5s cooling interval is automatically inserted. Then, the corresponding extended conductive fiber ends are exposed in the same manner as connection interfaces.

[0130] Electrode fabric mechanical property testing: A 20 mm long electrode fabric was fixed at both ends of a universal testing machine. A 10 N sensor was used, the tensile speed was set to 5 mm / min, and the strain was 20% of the initial fabric length. Repeated stretching and recovery were performed at a frequency of 1 Hz. The stress-strain curve of the electrode fabric during each tensile cycle was recorded. The reversible recovery ability of the electrode fabric was tested (see [reference needed]). Figure 3 The curve corresponding to a 1×1 rib stitch.

[0131] This invention also conducted mechanical property tests on unwoven flexible fiber electrodes, plain knitted fabrics, and 2×1 rib knitted fabrics. Detailed test results can be found in [link to test results]. Figure 3 As shown.

[0132] from Figure 3 It can be seen that the 1×1 rib knit fabric has a larger gap and layering on the fabric surface due to its alternating knit and purl structure, which provides more redundant structure to accommodate stretching. As a result, the rib fabric can provide more stretching space when the initial tension is applied, exhibiting greater stretchability, and therefore has the lowest tensile modulus.

[0133] Comparison of the electrical responses of electrode fabric and platinum wire electrodes: The electrical response characteristics of electrode fabric and platinum wire electrodes were tested using a three-electrode method with an electrochemical workstation. A silver / silver chloride electrode was used as the reference electrode, and a platinum electrode as the counter electrode. The electrode fabric or platinum wire electrode was connected to the working electrode position. During bipolar pulse testing, the maximum amplitude of the voltage signal was ±0.5V, and the voltage pulse frequency was set to 50Hz. The electrical response characteristics of the electrodes were analyzed using the current-voltage curves automatically recorded by the electrochemical workstation. Figure 4 As shown.

[0134] from Figure 4 It can be seen that in bipolar pulse tests with the same amplitude and frequency, the current response of the electrode fabric is significantly higher than that of the platinum wire electrode, with a response current approximately twice that of the platinum wire electrode. These advantages enable the electrode fabric to exhibit better performance in signal recording and electrical stimulation applications in bioelectronics.

[0135] It should be noted that, Figure 4 The gastric electromonitoring fabric in this embodiment is the electrode fabric prepared in this example.

[0136] Example 3

[0137] The biodegradable flexible fiber electrode prepared in Example 1 was used to prepare a fiber electrode fabric for monitoring gastric electrical activity in mice.

[0138] Step 3.1: Measure the average stomach size of experimental mice (ICR, 6 weeks old, male) in a normal animal room (with an independent air filtration system, air humidity of 40%, 12-hour light-dark cycle, ambient temperature of 22℃, sufficient water and food, and free access to food and water) when fasting. The stomach's greater curvature length is 1.8cm, lesser curvature length is 1.2cm, transverse diameter at the cardia is 0.35cm and circumference is 1.1cm, transverse diameter at the pylorus is 0.2cm and circumference is 0.63cm, and the widest part of the stomach body has a transverse diameter of 0.7cm and circumference of 2.2cm. This will serve as the basis for knitting modeling.

[0139] Step 3.2: Based on the knitting modeling in Step 3.1, the electrode fabric is knitted. The prepared fiber electrode and polyethylene glycol fiber are wound into a spool using a winding machine. Knitting lubricant is brushed onto the fiber electrode. Then, using the measured average stomach size as the basis for knitting modeling, polyethylene glycol fiber is used as the structural thread, and the fiber electrode is used as the conductive thread. Double-strand weft knitting is performed using a computerized flat knitting machine, and the tension during the knitting process is adjusted according to the size and shape requirements. The knitting program is adjusted so that the fiber electrode is knitted separately in even-numbered rows, and the movement trajectory of the fiber electrode is extended at the edge position. The extra extended fiber electrode portion is used for connection with external devices. Subsequently, the prepared fabric is immersed in anhydrous ethanol and ultrasonically cleaned for 10 min (power 100W, frequency 40kHz, temperature: 25±2℃), then rinsed 3 times with deionized water, and dried in a 60℃ oven for 60 min.

[0140] Step 3.3: Laser Engraving Exposure Signal Acquisition Window. The prepared electrode fabric is fixed to a three-dimensional laser processing platform, and a vacuum adsorption stage is used to keep the sample flat and wrinkle-free (adsorption pressure -80 kPa). A 355 nm wavelength ultraviolet laser is selected for the laser system, equipped with a 100 mm focal length flat lens. The processing path is generated using pre-imported three-dimensional gastric model data. The laser power is set to 8 W (corresponding to an energy density of 3.2 J / cm²), the pulse frequency to 30 kHz, and the scanning speed to 800 mm / s. A galvanometer scanning method is used to achieve precise positioning. Focal length calibration is performed before processing. A confocal displacement sensor is used to ensure the laser focus is located on the upper surface of the poly(1,8-octanediol-citrate) layer (Z-axis positioning accuracy ±1 μm), and 5×5 point surface height mapping compensation is performed in the edge area (sampling interval 2 mm). In actual engraving, a layered removal strategy was adopted, with each pass having a removal depth of 2μm, and a total of 5 rounds of engraving were performed (total engraving time approximately 45 s / window). The spacing between adjacent scanning paths was 10μm, and nitrogen-assisted purging (flow rate 15L / min) was used to promptly remove slag. The signal acquisition window array was arranged in 3 rows × 4 columns, with each window measuring 1×1mm and a center-to-center spacing of 3~4mm. A 20μm safety boundary was reserved on all four sides of each window to prevent damage to the conductive fibers. The heat-affected zone was monitored in real time during the engraving process, and an infrared thermal imager was used to ensure that the local temperature did not exceed 80℃ (sampling rate 10Hz). When the temperature exceeded the limit, a 0.5 s cooling interval was automatically inserted. Then, the corresponding extended conductive fiber ends were exposed in the same way.

[0141] Example 4

[0142] The fiber electrode fabric prepared in Example 3 was used to monitor gastric electrical activity in mice after abdominal surgery and to restore the physiological synchronization of gastric electrical rhythm by applying electrical stimulation.

[0143] The specific procedure was as follows: Eight-week-old male BALB / c mice were used. First, the mice were placed in an anesthesia induction chamber and anesthesia was induced by 4-5% isoflurane. After the mice lost their righting reflex, they were transferred to an operating table, and anesthesia was maintained by administering 1-1.5% isoflurane via a breathing mask. For the implantation group mice, a 2cm midline abdominal incision was made, the abdominal wall was dissected layer by layer, the stomach was located, and the fiber electrode fabric was wrapped around the gastric serosa (no additional fixation was required). The stomach was then repositioned, and the abdominal wound was sutured layer by layer. A 37°C constant temperature pad was provided on the operating table to maintain the mice's body temperature at 36.5±0.3°C. The control group mice underwent sham surgery; the surgical procedure was identical to that of the implantation group mice, except that the fiber electrode fabric was not implanted. The changes in the electrical properties of the fiber electrode fabric in vivo were monitored daily to assess the degradation process of the electrode fabric after implantation and its impact on electrical properties. Electrical performance tests were performed daily post-surgery to observe conductivity and stability. Simultaneously, a biosafety assessment was conducted 6 weeks post-surgery.

[0144] The anesthesia, laparotomy, and closure procedures for the experimental group mice were the same as those for the implantation group mice. After laparotomy, the stomach was located and the mesentery was fully exposed. The stomach and mesentery of the mice were pulled with forceps, and the root of the superior mesenteric artery was located. The root of the superior mesenteric artery was clamped with a vascular clamp that would not damage the blood vessels. After 30 minutes, the vascular clamp was removed to restore blood flow. Then, the fiber electrode fabric was wrapped around the serosa of the stomach. After the organs were returned to their original positions, the abdominal cavity was closed. Postoperatively, gastric electrical activity was monitored and synchronous electrical stimulation therapy was administered.

[0145] Please see Figure 5 and Figure 6 , Figure 5 A schematic diagram showing the fiber electrode fabric fixed to the surface of the stomach, wherein, Figure 5 (a) in the diagram is a structural diagram of the stomach after abdominal surgery. Figure 5 (b) is a schematic diagram of a fiber electrode fabric implanted on the surface of the stomach. Figure 5 (b) The text description on the right is a functional description of the fiber electrode fabric. Figure 6 This is a photograph of the surface of a mouse stomach after abdominal surgery, showing the implantation of a fiber electrode fabric.

[0146] For details on the changes in electrical properties of the implanted mice, please refer to [link / reference]. Figure 7 As shown, from Figure 7 It can be seen that the electrical properties of the electrode fabric gradually decline over time. It exhibits stability before degradation within 80 days post-surgery, and then gradually loses its electrical properties as the material degrades, with significant performance loss occurring on day 86.

[0147] Biosafety assessment after implantation: Following electrode fabric implantation, a biosafety assessment was conducted. Six weeks post-operation, blood samples were collected from both the control and implantation groups to determine complete blood count and liver and kidney function. Detailed assessment results are available in [link to relevant documentation]. Figures 8 to 10,in, Figure 8 (a) shows the white blood cell (WBC) counts in the control group and the implantation group mice. Figure 8 (b) shows the red blood cell (RBC) counts in the control group and the implantation group mice. Figure 8 (c) represents the hemoglobin concentration (HGB) of the control group mice and the implantation group mice. Figure 9 (a) shows the alanine aminotransferase (ALT) levels in the control group and the implantation group mice. Figure 9 (b) shows the detection results of aspartate aminotransferase (ALT) in the control group mice and the implantation group mice; Figure 10 (a) shows the blood urea nitrogen (BUN) levels in the control group and the implantation group mice. Figure 10 (b) shows the serum creatinine (CREA) levels in the control group and the implantation group mice. Figures 8 to 10 As can be seen, no significant increase in inflammatory cells was observed in the blood compared to the control group, and no obvious immune or hepatotoxic reactions were triggered, confirming its good biocompatibility. The results indicate that this electrode material has excellent biosafety.

[0148] In vivo monitoring and treatment effects of the electrode fabric: The extended fiber electrode ends (connection interfaces) of each electrode channel were connected to a custom-made ribbon cable, and the other end of the ribbon cable was directly and quickly connected to the electrophysiological recording device. Slow wave potentials (sampling rate 1 kHz, bandwidth 0.1–30 Hz, signal-to-noise ratio >20 dB; normal mice: 3–5 times / min) were successfully recorded 24–48 hours post-surgery in the experimental group mice. When postoperative gastric electrical disturbances (such as slow wave frequency <2 times / min or rhythm desynchronization) were confirmed, synchronous gastric electrical stimulation was administered using a pulse sequence (frequency 40 Hz, pulse width 2 ms, amplitude 4 mA), duration 0.5–0.8 s, synchronized with the peak value of endogenous slow waves in the stomach. After closed-loop electrical stimulation treatment, the gastric electrogram returned to normal. (See [link to relevant documentation]). Figure 11 As shown.

[0149] from Figure 11 It can be seen that all four channels on the electrode fabric effectively recorded the gastric electrical activity of the experimental group mice after surgery. Channels 1 and 2 recorded roughly normal slow wave potentials, while channels 3 and 4 recorded disordered gastric electrical activity, suggesting that there may be postoperative local gastric motility disorders at the corresponding sites. When the postoperative gastric electrical disorder was confirmed in the experimental group mice, channels 3 and 4 were given synchronous gastric electrical stimulation. The results showed that the gastric electrogram returned to normal after electrical stimulation treatment, confirming the effectiveness of the treatment.

[0150] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a biodegradable fiber electrode fabric for three-dimensional gastric electrography monitoring, characterized in that, Includes the following steps: Step S10: The biodegradable polyglycolic acid fiber is subjected to plasma treatment, and a gold layer is deposited on the surface of the plasma-treated polyglycolic acid fiber to prepare gold / polyglycolic acid fiber. Step S20: Polypyrrole transduction layer is polymerized in situ on the gold layer surface of the gold / polyglycolic acid fiber to prepare polypyrrole / gold / polyglycolic acid fiber; Step S30: In situ reduction of gold nanoparticles on the surface of the polypyrrole transduction layer of the polypyrrole / gold / polyglycolic acid fiber to prepare gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber; Step S40: Coating a poly(1,8-octanediol citrate) solution onto the surface of the gold nanoparticle layer of the gold nanoparticle / polypyrrole / gold / polyglycolic acid fiber to form an insulating layer, thereby preparing a biodegradable flexible fiber electrode. Step S50: Using knitting technology, the flexible fiber electrode and polyglycolic acid fiber are simultaneously woven to form a three-dimensional flexible fabric structure. The insulating layer of the target area on the flexible fabric structure is removed to expose the conductive layer, resulting in a biodegradable fiber electrode fabric. The target area includes multiple first areas and multiple second areas. Multiple signal acquisition windows formed by removing the insulating layers of the multiple first areas are used as a distributed electrode array to acquire gastric electrical signals. Multiple connection interfaces formed by removing the insulating layers of the multiple second areas are used for electrical connection with external electrophysiological recording equipment. Each of the multiple connection interfaces corresponds to one of the multiple signal acquisition windows.

2. The preparation method according to claim 1, characterized in that, The polyglycolic acid fiber in step (1) is a pretreated polyglycolic acid fiber. The pretreatment steps of the polyglycolic acid fiber include ultrasonic cleaning with acetone as the cleaning agent, ultrasonic cleaning with anhydrous ethanol as the cleaning agent, rinsing with deionized water and vacuum drying in sequence. The method for plasma treatment of pretreated polyethylene glycol fibers includes: plasma treatment at a power of 50W for 5 minutes in a mixed gas composed of O2 and Ar.

3. The preparation method according to claim 2, characterized in that, The gold layer thickness is 40~80nm, and the process parameters for depositing the gold layer on the surface of the plasma-treated polyglycolic acid fiber include: a deposition rate of 0.3~0.5 Å / s and a deposition time of 1500~2500s.

4. The preparation method according to claim 1, characterized in that, The thickness of the polypyrrole transducer layer is 50~150μm, and the step of in-situ polymerization of the polypyrrole transducer layer on the gold plating surface of the gold / polyglycolic acid fiber includes: First, the pyrrole aqueous dispersion and potassium nitrate solution are mixed evenly to obtain an soaking solution. Then, the gold / polyglycolic acid fiber is soaked in the soaking solution until the polyglycolic acid fiber in the gold / polyglycolic acid fiber is fully impregnated. A polypyrrole transconducting layer is polymerized on the gold layer surface of the impregnated gold / polyglycolic acid fiber using either chemical oxidative polymerization or electrochemical methods. The chemical oxidative polymerization method involves adding ferric chloride solution dropwise to an impregnation solution containing the gold / polyglycolic acid fiber under ice bath and shaking conditions. After the reaction is complete, the gold / polyglycolic acid fiber loaded with polypyrrole is removed, cleaned of impurities, and polypyrrole / gold / polyglycolic acid fiber is obtained. The electrochemical method involves electrically connecting the gold / polyglycolic acid fiber to a copper foil wire and placing it in an electrolytic cell containing a mixed solution of pyrrole and potassium nitrate. Using a first three-electrode system, a constant potential method is employed, applying a potential of +0.7V relative to the reference electrode of the first three-electrode system and maintaining this potential for 120-300 seconds. After cleaning, the fiber is removed and polypyrrole / gold / polyglycolic acid fiber is obtained. In the first three-electrode system, the gold / polyglycolic acid fiber serves as the working electrode, a calomel electrode as the reference electrode, and a platinum wire as the counter electrode.

5. The preparation method according to claim 1, characterized in that, The thickness of the gold nanoparticle layer is 50~100nm. In step S30, gold nanoparticles are reduced in situ on the surface of the polypyrrole transducer layer of the polypyrrole / gold / polyglycolic acid fiber using an electroreduction method or a chemical reduction method, wherein: The electroreduction method includes: first, immersing the polypyrrole / gold / polyglycolic acid fiber in hydrochloric acid solution to activate the surface; then, electrically connecting the polypyrrole / gold / polyglycolic acid fiber to a copper foil wire, and then placing it in an electrolytic cell of tetrachloroauric acid solution. Using a second and third electrode system, a constant potential method is employed, applying a potential of -0.2V relative to the reference electrode of the second and third electrode system, maintaining it for 6 seconds, and then removing it. After cleaning, gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber are prepared. In the second and third electrode system, polypyrrole / gold / polyglycolic acid fiber is used as the working electrode, a silver / silver chloride electrode is used as the reference electrode, and a platinum wire electrode is used as the counter electrode. The chemical reduction method includes: first, placing the polypyrrole / gold / polyglycolic acid fiber in a reaction tank with deionized water to fully impregnate the polyglycolic acid fiber in the polypyrrole / gold / polyglycolic acid fiber; then, adding sodium formate solution and tetrachloroauric acid solution to the reaction tank to react until the reaction is complete; after cleaning, gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber is prepared.

6. The preparation method according to claim 1, characterized in that, Step S40 includes: Step A: Mix the solute poly(1,8-octanediol-citrate) and solvent dichloromethane according to a preset mass ratio, and stir continuously at 40~50°C for 2~4 hours until the solution is completely clear and transparent to prepare a poly(1,8-octanediol-citrate) solution, wherein the molecular weight of poly(1,8-octanediol-citrate) is 15~20kDa, and the preset mass ratio of poly(1,8-octanediol-citrate) to dichloromethane is 1:1~2; Step B: The poly(1,8-octanediol-citrate) solution is coated onto the surface of the gold nanoparticle layer of gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber. The solvent dichloromethane is removed by standing at room temperature and vacuum drying to form an insulating layer on the gold nanoparticle layer of gold nanoparticles / polypyrrole / gold / polyglycolic acid fiber, thus preparing a biodegradable flexible fiber electrode.

7. The preparation method according to any one of claims 1 to 6, characterized in that, The biodegradable fiber electrode fabric includes a main body for wrapping the gastric serosal surface and a plurality of connecting fiber electrodes extending from the main body. The connecting fiber electrodes include a connecting end connected to the main body and an end opposite to the connecting end. A plurality of signal acquisition windows are disposed on the main body, and a plurality of connection interfaces are disposed at the ends of the plurality of connecting fiber electrodes that correspond to the plurality of signal acquisition windows.

8. The preparation method according to claim 7, characterized in that, The step of simultaneously weaving the flexible fiber electrode and polyethylene glycol fiber into a three-dimensional flexible fabric structure using knitting technology includes: The flexible fiber electrode and the polyethylene glycol fiber are respectively wound into a shaft; Obtain the dimensions of the fabric structure to be woven, and use these dimensions as the basis for knitting modeling; Using polyethylene glycol fiber as the structural wire and flexible fiber electrodes as the conductive wire, a three-dimensional flexible fabric structure is woven using knitting technology based on knitting modeling. The knitting technology includes: using double-strand knitting for odd-numbered rows and single-strand knitting for even-numbered rows. The double-strand knitting is woven from flexible fiber electrodes and polyethylene glycol fiber, and the single-strand knitting is woven using flexible fiber electrodes. At the same time, during single-strand knitting, the movement trajectory of the flexible fiber electrodes is extended at the edge position to form the connecting fiber electrodes.

9. The preparation method according to claim 8, characterized in that, The insulating layer is 10~20μm thick. Laser engraving technology is used to remove the insulating layer in the target area to form multiple signal acquisition windows and multiple connection interfaces. The laser engraving technology includes: using a layered removal strategy, setting the removal depth to 2μm for each pass, performing 5~10 passes of cyclic engraving, with an adjacent scanning path spacing of 10μm, and timely removal of slag by nitrogen-assisted purging.

10. A biodegradable fiber electrode fabric for three-dimensional gastric electrography monitoring, characterized in that, The fiber electrode fabric is prepared using the preparation method described in any one of claims 1 to 9.

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