Medical surgical electrode and preparation method thereof

Abstract

The invention provides a medical surgical electrode and a preparation method thereof, and belongs to the field of medical instruments. The invention provides a medical surgical electrode. The medical surgical electrode comprises a silver matrix and graphene oxide dispersed in the silver matrix. The graphene oxide is added to improve the mechanical property of the pure silver and improve the electric conduction and heat conduction properties of the pure silver at the same time, so that the electrode is suitable for medical operation electrodes, the electrode cutting efficiency can be improved, adhesion is relieved, and the thermal damage risk is reduced. The preparation process is mature, the product performance is good, and the application prospect is wide.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically to a medical surgical electrode and its preparation method. Background Technology

[0002] With the rapid development of minimally invasive surgical techniques, medical surgical electrodes, as core instruments in high-frequency electrosurgery, can quickly perform operations such as tissue cutting and coagulation, helping doctors complete surgical tasks accurately and safely in a shorter time. However, the high temperature generated on the electrode surface during surgical cutting can cause the vaporization of blood and body fluids in the tissue, resulting in blood and soft tissue adhesion, forming eschar, and affecting the surgical outcome.

[0003] Existing stainless steel or alloy electrodes cause tissue carbonization due to high temperatures during cutting, forming eschar that adheres to the surface, increases resistance, reduces surgical efficiency, requires frequent cleaning, and prolongs surgical time. Summary of the Invention

[0004] This invention provides a medical surgical electrode and its preparation method. The medical surgical electrode of this invention has high cutting efficiency and low adhesion.

[0005] The present invention provides a medical surgical electrode comprising a silver matrix and graphene oxide dispersed in the silver matrix.

[0006] Preferably, it also includes reduced graphene oxide and / or graphene.

[0007] The present invention also provides a method for preparing the medical surgical electrode described in the above technical solution, comprising the following steps: The medical surgical electrode is obtained by mixing graphene oxide and silver powder, followed by molding and sintering.

[0008] Preferably, the mass of the graphene oxide is 0.5 to 3% of the total mass of the graphene oxide and silver powder.

[0009] Preferably, the mixing includes: dispersing graphene oxide in a first alcohol solvent to obtain a dispersion of graphene oxide; Silver powder is dispersed in a second alcohol solvent to obtain a dispersion of silver powder; The dispersion of graphene oxide was mixed with the dispersion of silver powder and stirred. The resulting mixture was then dried to obtain a dried mixture. The dried mixture is ball-milled.

[0010] Preferably, the first alcohol solvent and the second alcohol solvent comprise ethanol.

[0011] Preferably, the grinding balls used in the ball mill have a diameter of 8-12 mm and are made of agate; The ball mill has a ball-to-material ratio of 5:1, a rotation speed of 300 rpm, and a time of 4 hours. The ball mill operates alternately in both forward and reverse directions, switching directions every 15 minutes.

[0012] Preferably, the molding pressure is 600 MPa and the holding time is 5 min.

[0013] Preferably, the sintering temperature is 840°C, the holding time is 2 hours, and the pressure is 650 MPa; The sintering is carried out in an inert gas.

[0014] Preferably, the heating rate to the sintering temperature is 20°C / min.

[0015] The addition of graphene oxide improves the mechanical properties of pure silver (pure silver has very low hardness and is easily worn when used in surgical electrodes) while also enhancing its electrical and thermal conductivity. This makes it suitable for medical surgical electrodes, improving electrode cutting efficiency, reducing adhesion, and lowering the risk of thermal damage. Its preparation process is mature, the product performs well, and it has broad application prospects. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the preparation process of the anti-adhesion silver / graphene oxide composite material for medical surgical electrodes, as shown in the example. Figure 2 X-ray diffraction patterns of graphene oxide (GO), graphene (GP), and silver / graphene oxide (Ag / GO) composite powder from Example 1; Figure 3 The XRD patterns of the silver / graphene oxide composite bulk materials in Examples 1-3 are shown below. Figure 4 Metallographic micrographs of the silver / graphene oxide composite materials in Examples 1-3; Figure 5 SEM micrographs of the silver / graphene oxide composite materials in Examples 1-3; Figure 6 Here are SEM micrographs and EDS images of the silver / graphene oxide composite material from Example 3; Figure 7 The hardness variation curves of the silver / graphene oxide composite materials in Examples 1-3 are shown. Figure 8 The resistivity variation curves of the silver / graphene oxide composite materials in Examples 1-3 are shown. Figure 9 The thermal diffusivity curves of the silver / graphene oxide composite materials in Examples 1-3 are shown. Figure 10 The thermal conductivity variation curves of the silver / graphene oxide composite materials in Examples 1-3 are shown. Figure 11Simulate the surface adhesion before and after thermal cutting experiments using blades made of different materials; Figure 12 To simulate the weight of adherent tissue before and after thermal cutting experiments. Detailed Implementation

[0017] The present invention provides a medical surgical electrode comprising a silver matrix and graphene oxide dispersed in the silver matrix.

[0018] In this invention, the medical surgical electrode preferably further includes reduced graphene oxide and / or graphene.

[0019] The present invention also provides a method for preparing the medical surgical electrode described in the above technical solution, comprising the following steps: The medical surgical electrode is obtained by mixing graphene oxide and silver powder, followed by molding and sintering.

[0020] In this invention, the mixing preferably includes: dispersing graphene oxide in a first alcohol solvent to obtain a dispersion of graphene oxide; Silver powder is dispersed in a second alcohol solvent to obtain a dispersion of silver powder; The dispersion of graphene oxide was mixed with the dispersion of silver powder and stirred. The resulting mixture was then dried to obtain a dried mixture. The dried mixture is ball-milled.

[0021] In this invention, the first alcohol solvent and the second alcohol solvent preferably include ethanol.

[0022] In this invention, the diameter of the grinding balls used in the ball mill is preferably 8-12 mm, and the material is preferably agate; the ball-to-material ratio of the ball mill is preferably 5:1, the rotation speed is preferably 300 rpm, and the time is preferably 4 hours; the ball milling is preferably carried out alternately in forward and reverse directions, and the direction is switched every 15 minutes.

[0023] In this invention, the preferred mass of the graphene oxide is 0.5-3% of the total mass of the graphene oxide and silver powder. In specific embodiments of this invention, it can be 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, or 2.8%.

[0024] In this invention, the molding pressure is preferably 600 MPa, and the holding time is preferably 5 min.

[0025] In this invention, the sintering temperature is preferably 840°C, the holding time is preferably 2 hours, the sintering is preferably carried out in an inert gas, and the heating rate to the sintering temperature is preferably 20°C / min.

[0026] The following detailed description of the medical surgical electrode and its preparation method provided by the present invention, with reference to the embodiments, should not be construed as limiting the scope of protection of the present invention.

[0027] The instruments used in this invention: BQS-10a ultrasonic cleaner, Hangzhou Blancpain Ultrasonic Technology Co., Ltd. YHM-5003 Electronic Balance, Huizhou Yingheng Electronic Technology Co., Ltd.; TM200 Metal Rolling Mill, Taimao Machinery; Eco2S-L Grinding and Polishing Machine, Shandong Weiyi; Vacuum hot pressing sintering furnace, Shanghai Bona Thermal Furnace Co., Ltd.; LPB-0.4L ball mill, LAISDA; 0HWS24 Electric Thermostatic Water Bath; DZF-AS vacuum drying oven; JSM-7800F scanning electron microscope, JSM Corporation, Japan; DMi8 inverted metallurgical microscope, Leica; D8 Advance X-ray diffractometer, Bruker, Germany; Z100HT Universal Testing Machine for Metal Materials, ZWUK ROOLL; RTS-11 Metal Four-Probe Tester, Guangzhou Four-Probe Technology; LFA 467HT laser thermal conductivity meter, Netzsch; HVS-1000b Vickers Hardness Tester, HUAYIN.

[0028] Example 1 The preparation process route of anti-adhesion silver / graphene oxide composite material for medical surgical electrodes is as follows: Figure 1 As shown, the specific steps are as follows: (1) Composition ratio Weigh out graphene oxide powder and silver powder (balance) at 0.5% by mass, for a total mass of 20 g.

[0029] (2) Dispersion and mixing Weighed graphene oxide powder and silver powder were added to 50 mL of anhydrous ethanol and ultrasonically vibrated for 30 min to ensure uniform dispersion of graphene oxide powder and silver powder and avoid particle agglomeration. The two dispersions after ultrasonic vibration were combined into a beaker and placed in a constant temperature water bath (temperature 25℃) and stirred for 30 min to ensure uniform mixing of graphene oxide powder and silver powder. The mixed liquid was placed in a vacuum drying oven at 60℃ until completely dried to obtain mixed powder.

[0030] (3) Ball milling and powder mixing The mixed powder was placed into the ball mill jar of a planetary ball mill. A polytetrafluoroethylene ball mill jar and agate grinding balls with a diameter of 8~12mm were selected. The ball-to-material ratio was 5:1. The constant speed was set to 300 rpm. The mill was run alternately in forward and reverse directions, and the direction was switched every 15 minutes. The milling was carried out for 4 hours to obtain a silver / graphene oxide composite powder with uniform composition. (4) Cold pressing preforming The ball-milled composite powder was loaded into a Φ10 mm mold, and the inner wall was sprayed with boron nitride lubricant to reduce friction. The mold was then pressurized unidirectionally at 600 MPa on a hydraulic press and held for 5 min to prepare a high-density preform.

[0031] (5) Hot pressing and sintering The pre-formed compact was placed in a vacuum hot-pressing sintering furnace and sintered at 840℃, 650MPa, and under nitrogen atmosphere protection. The heating rate was 20℃ / min, and the temperature and pressure were maintained for 2 hours to produce a composite block.

[0032] Example 2 The only difference from Example 1 is that the mass fraction of graphene oxide is 1.5%.

[0033] Example 3 The only difference from Example 1 is that the mass fraction of graphene oxide is 3%.

[0034] Figure 2 X-ray diffraction patterns of graphene oxide (GO), graphene (GP), and silver / graphene oxide (Ag / GO) composite powders from Example 1.

[0035] from Figure 2 It can be observed that the (002) characteristic peak of graphene is located near 2θ=26°, corresponding to its few-layer graphene layered structure with a small interlayer spacing. The (001) characteristic peak of graphene oxide is located near 2θ=11.5°, corresponding to its larger interlayer spacing and intercalation structure with oxygen-containing functional groups. In the X-ray diffraction pattern of the silver / graphene oxide composite powder, a strong diffraction peak of silver was observed, but the 11.5° peak of graphene oxide was not detected. This is mainly because the content of graphene oxide in the mixed powder is only 0.5 wt%, which exceeds the detection range of XRD. Another possible reason is that silver, with its high atomic number, has a stronger absorption effect on X-rays, further weakening the X-ray signal of graphene oxide and reducing its diffraction intensity.

[0036] Figure 3 The images show the XRD patterns of the silver / graphene oxide composite blocks in Examples 1-3.

[0037] from Figure 3In spectrum (a), strong diffraction peaks of silver are clearly visible, while diffraction peaks of graphene oxide are not obvious. A partial magnification of the XRD pattern of the composite bulk with 3% graphene oxide (e.g., Figure 3 As shown in (b), a weak C(001) characteristic peak was observed near 2θ=11°, indicating the presence of graphene oxide in the silver matrix. Notably, a C(002) characteristic peak appeared near 2θ=26°, which is the characteristic peak position of graphene. The peak position of reduced graphene oxide (rGO) is also nearby. The reason for this peak is that under high-temperature sintering at 840℃, some graphene oxide was deoxygenated and converted into reduced graphene oxide or graphene, leading to a reduction in interlayer spacing and thus the appearance of a new characteristic peak. The weak characteristic peak at 2θ=11° indicates that some unreduced graphene oxide still maintains its original layered structure. Furthermore, no other new peaks appeared in the spectrum besides the characteristic peaks of silver, graphene oxide, graphene, and reduced graphene oxide, and the characteristic peak of silver did not show significant changes, proving that the combination of silver and graphene oxide is a purely physical combination, without the formation of a compound or solid solution.

[0038] Figure 4 Metallographic micrographs of the silver / graphene oxide composite materials in Examples 1-3. Figure 4 Images (a) to (c) are metallographic micrographs of the silver / graphene oxide composite materials of Examples 1 to 3, respectively.

[0039] Depend on Figure 4 Black dot-like or elongated granular structures were observed distributed within the gray matrix, suggesting that the black areas are graphene oxide or graphene, while the gray areas represent the silver matrix. When the graphene oxide content was 0.5 wt%, most of the graphene oxide was uniformly distributed as dot-like particles within the silver matrix, with relatively small sizes, indicating good dispersibility and minimal localized agglomeration at this concentration. As the graphene oxide content increased, reaching 1.5 wt%, the size of the black areas gradually increased, the number of dot-like particles decreased, and the number of elongated particles gradually increased, indicating a gradual decrease in the dispersibility of graphene oxide within the silver matrix and an increase in agglomeration. When the graphene oxide content reached 3.0 wt%, the size of the black areas further increased, with more and larger elongated particles, indicating poor dispersibility of graphene oxide within the silver matrix and exacerbated agglomeration. This is mainly attributed to the high specific surface area and surface energy of graphene oxide sheets, which remain in an energy-unstable state during mixing and sintering with silver powder. As the content increases, the interlayer spacing of graphene oxide shortens, at which point van der Waals forces exceed their own gravity, thus inducing aggregation. In addition, the growth driving force of silver grains during high-temperature sintering also increases the aggregation tendency of graphene oxide.

[0040] Figure 5 SEM micrographs of silver / graphene oxide composite materials in Examples 1-3. Figure 5 Images (a) to (c) are SEM micrographs of the silver / graphene oxide composite materials of Examples 1 to 3, respectively.

[0041] Depend on Figure 5 In (a), graphene oxide can be further observed to exist in the silver matrix as numerous dot-like particles and a small number of strip-like particles, with uniform distribution and slight agglomeration. Figure 5 The results in (b) and (c) are consistent with the metallographic micrograph analysis. As the content of graphene oxide increases, the area of ​​dot graphene oxide gradually increases, the strip graphene oxide becomes more dense, and the aggregation phenomenon intensifies.

[0042] Figure 6 The images shown are SEM micrographs and EDS images of the silver / graphene oxide composite material in Example 3.

[0043] from Figure 6 In (a), it can be clearly observed that the strip-shaped graphene oxide particles aggregate to form a divergent, locally continuous network structure. Figure 6 As shown in (b), the distribution of element C in the silver matrix confirms the elemental aggregation phenomenon under high graphene oxide content.

[0044] Figure 7 The hardness variation curves of the silver / graphene oxide composite materials in Examples 1-3 are shown.

[0045] from Figure 7It can be observed that when the graphene oxide content is 0.5 wt%, the hardness of the silver / graphene oxide composite material reaches 81 HV, which is significantly improved by 90.14% compared with the 42.6 HV of pure silver. This reflects that the low-content graphene oxide is uniformly dispersed in the silver matrix through a two-dimensional layered structure. Combined with the analysis of the microstructure of the silver / graphene oxide composite material, on the one hand, the dot-like graphene oxide particles inhibit grain growth by pinning at the grain boundaries, thereby producing a grain refinement effect. The fine grains reduce internal defects in the material, thus improving the hardness of the material. On the other hand, the sp2 hybrid orbitals of C atoms connected by covalent bonds give graphene oxide high strength. The presence of C atom layers maintains the stability of the structure. At the same time, the graphene oxide particles distributed in the silver matrix hinder dislocation slip, resulting in a hardening effect. As the graphene oxide content increased to 1.5 wt%, the hardness of the silver / graphene oxide composite material decreased to 77.3 HV. This is because the oxygen-containing functional groups on the surface of the graphene oxide sheets partially decomposed during high-temperature sintering, leading to a decrease in interfacial bonding strength. Furthermore, the number of strip-shaped graphene oxide particles gradually increased, and localized agglomeration caused stress concentration, weakening the matrix hardness. With the graphene oxide content further increasing to 3.0%, the hardness dropped significantly to 67.3 HV. Combined with the microstructure analysis described earlier, this indicates an increase in the distribution of strip-shaped graphene oxide particles in the silver matrix. The graphene oxide sheets experienced severe agglomeration due to van der Waals forces and π-bond interactions, forming microscopic defects and disrupting the continuity of the silver matrix. Simultaneously, high-temperature sintering produced more reduced graphene oxide (rGO), leading to increased interlayer shrinkage and interfacial separation, resulting in a poorer hardening effect.

[0046] Figure 8 The resistivity variation curves of the silver / graphene oxide composite materials in Examples 1-3 are shown.

[0047] from Figure 8It can be observed that the resistivity of the silver / graphene oxide composite material first decreases and then increases with the increase of graphene oxide content. When the graphene oxide content is 0.5 wt%, the resistivity of the composite material is the lowest at 1.587 μΩ·cm, which is 2.69% lower than the resistivity of pure silver (1.631 μΩ·cm), indicating the lowest resistivity and conductivity. The C atoms in graphene oxide are connected in an sp2 hybridized form, with three d bonds in each lattice forming a stable hexagonal structure. Each C atom can contribute a p orbital to form a π bond, where π electrons can move freely. Adding a small amount of graphene oxide to the silver matrix facilitates the formation of a three-dimensional continuous conductive grid. Its two-dimensional sheet structure promotes the cooperative transport of π electrons and free electrons in silver, while suppressing the scattering of electrons by grain boundaries, thus improving conductivity. When the graphene oxide content increased to 1.5 wt%, the resistivity rebounded to 1.613 μΩ·cm, reflecting that the local aggregation of graphene oxide disrupted the integrity of the continuous three-dimensional network conductive pathway, forming an electronic barrier that hindered the transport of free electrons and reduced conductivity. When the graphene oxide content further increased to 3.0 wt%, the resistivity rose to 1.633 μΩ·cm, a slight increase compared to the resistivity of pure silver (1.631 μΩ·cm). This is attributed to the large-scale aggregation of graphene oxide sheets disrupting the continuity of the silver matrix, further damaging the three-dimensional network conductive pathway. Furthermore, high-temperature sintering led to an increase in defects after the reduction of graphene oxide to reduced graphene oxide, resulting in sp2 hybrid orbitals and enhanced electron scattering, which is detrimental to free electron conduction and reduces conductivity.

[0048] Figure 9 The thermal diffusivity curves of the silver / graphene oxide composite materials in Examples 1-3 are shown.

[0049] from Figure 9 It can be observed that the thermal diffusivity of the silver / graphene oxide composite material initially increases and then decreases with the addition of graphene oxide. When the graphene oxide content is 0.5 wt%, the thermal conductivity of the material at room temperature is 0.428 W / (mm·K), which is 2.15% higher than that of pure silver (0.419 W / (mm·K). This is mainly because the two-dimensional sheet morphology of graphene oxide forms a continuous thermally conductive grid structure in the silver matrix, reducing phonon scattering and improving thermal conductivity. As the graphene oxide content increases, the thermal conductivity gradually decreases. This is mainly attributed to the local agglomeration of graphene oxide, which disrupts the continuity of the thermal conductive pathway, hindering phonon propagation. Furthermore, high-temperature sintering reduces graphene oxide to reduced graphene oxide, causing interlayer shrinkage and resulting in decreased thermal conductivity. Combined with the previous analysis of density, the addition of graphene oxide decreases the density of the composite material and increases the porosity, weakening the thermal conductivity of the matrix.

[0050] Figure 10The curves showing the change in thermal conductivity of the silver / graphene oxide composite materials in Examples 1-3 are shown.

[0051] from Figure 10 It was observed that the thermal conductivity of all samples decreased with increasing temperature. Among them, when the graphene oxide content was 0.5 wt%, the thermal conductivity decreased more slowly than that of pure silver, indicating that its continuous thermally conductive grid still maintained some stability at high temperatures.

[0052] Figure 11 To simulate the surface adhesion before and after cutting for blades made of different materials in thermal cutting experiments.

[0053] Figure 11 It can be observed that the 304 stainless steel blade sample numbered 22# has the most severe adhesion on its surface, while the other silver / graphene oxide composite material samples have less adhesion and are lighter in color than the stainless steel adhesion.

[0054] Figure 12 To simulate the weight of adhered tissue before and after cutting in a thermal cutting experiment. The simulated thermal cutting experiment involved machining a block of silver / graphene oxide powder into a blade shape. The blade was heated to 350°C using a temperature-controlled soldering iron, and the pork belly tissue was cut. The quality of tissue adhesion was then evaluated.

[0055] Depend on Figure 12 It can be seen that at the same temperature (350℃), the average adhering mass of a blade made of 304 stainless steel is 85.2 mg, which is 4.78 times that of a silver / graphene oxide blade (17.8 mg). This is mainly due to the low thermal conductivity of 304 stainless steel, which makes it difficult for heat to dissipate quickly at the blade-tissue interface, resulting in a continuous increase in the blade-tissue interface temperature. Silver alloys, on the other hand, have good thermal conductivity, allowing heat to dissipate rapidly at the tissue interface, resulting in better cutting efficiency and less adhering mass.

[0056] Figures 11-12 01# represents silver, 31# represents the silver / graphene oxide composite material of Example 1, 32# represents the silver / graphene oxide composite material of Example 2, and 33# represents the silver / graphene oxide composite material of Example 3.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A medical surgical electrode, characterized by The silver-based electrode comprises a silver base and graphene oxide dispersed in the silver base.

2. The medical surgical electrode of claim 1, wherein, The silver-based electrode also comprises reduced graphene oxide and / or graphene.

3. The method of making a medical surgical electrode according to claim 1 or 2, wherein, The silver-based electrode comprises the following steps: After mixing the graphene oxide and silver powder, the mixture is formed and sintered to obtain the medical surgical electrode.

4. The production method according to claim 3, characterized by, The mass of the graphene oxide is 0.5-3% of the total mass of the graphene oxide and silver powder.

5. The production method according to claim 3, wherein The mixing comprises dispersing the graphene oxide in a first alcohol solvent to obtain a graphene oxide dispersion; dispersing the silver powder in a second alcohol solvent to obtain a silver powder dispersion; mixing the graphene oxide dispersion and the silver powder dispersion, stirring the mixture, and then drying the mixture to obtain a dry mixture; ball-milling the dry mixture.

6. The production method according to claim 5, wherein The first alcohol solvent and the second alcohol solvent comprise ethanol.

7. The preparation method according to claim 5, characterized in that, The diameter of the grinding balls used in the ball-milling is 8-12 mm, and the material of the grinding balls is agate; The ball-milling is performed at a ball-to-material ratio of 5:1, a rotation speed of 300 rpm, and a time of 4 h; the ball-milling is performed in an alternating manner, and the direction is switched every 15 min.

8. The preparation method according to claim 3, characterized in that, The pressure for the forming is 600 MPa, and the pressure maintaining time is 5 min.

9. The preparation method according to claim 3, characterized in that, The sintering is performed at a temperature of 840℃, a holding time of 2 h, and a pressure of 650 MPa; The sintering is performed in an inert gas.

10. The method of claim 9, wherein, The heating rate for heating to the sintering temperature is 20℃ / min.

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