A method for surface modification of a surgical electrotome

Abstract

The application relates to a surface modification process, in particular to a surgical electric knife surface modification method, which can improve the tissue adhesion resistance of a surgical knife and maintain low cytotoxicity, low resistance and appropriate wear resistance of the surgical knife. A graphite-like film layer inlaid with TaN particles is prepared on the surface of the surgical electric knife through a magnetron sputtering process. During the deposition process, a graphite-like layer with a micro-nano structure is first obtained on the surface of the surgical knife, and the graphite-like layer serves as a transition layer, so that the combination performance of the whole film layer with the cutter substrate is improved, then the Ta target is opened and nitrogen is introduced, the TaN particles are precipitated while the graphite-like layer is deposited, and the particles are embedded in the surface growth of the graphite-like layer. Therefore, the surgical knife can improve the tissue adhesion resistance, and maintain low cytotoxicity, low resistance and appropriate wear resistance of the surgical knife.

Description

Technical Field

[0001] This application relates to a surface modification process, specifically a method for modifying the surface of a surgical electrosurgical unit. Background Technology

[0002] Surgical scalpels have evolved from simple carbon steel blades to modern high-tech products integrating incision, hemostasis, and aspiration, such as high-frequency electrosurgical units, ultrasonic scalpels, and laser scalpels. Different types of scalpels are used in different surgical procedures, each with its own advantages. High-frequency electrosurgical units, as a new type of surgical scalpel, combine incision, dissection, scraping, and hemostasis functions, significantly reducing the number of scalpel changes during surgery, shortening operation time, reducing patient bleeding, and improving surgical efficiency. High-frequency electrosurgical units utilize high-density high-frequency current to generate high-voltage current at the electrode tip. This high-voltage current can burst or vaporize the soft tissue in contact with the electrode tip, ultimately achieving the purpose of cutting, hemostasis, or cauterization. This mainly applies the principle of high-frequency current thermal effect in medical physics. However, tissue adhesion to the electrosurgical unit can hinder energy delivery, preventing hemostasis and leading to poor wound healing. Therefore, many scholars have studied the adhesion of high-frequency electrosurgical units, finding that surface coating and surface microtexturing methods can improve adhesion. Domestically and internationally, most methods utilize titanium fluoropolymer coatings to improve the anti-scorching performance of the scalpel tip surface. However, since titanium fluoropolymer decomposes at a temperature of 300-350℃, the coating will decompose at the operating temperature of the scalpel, producing toxic substances that can harm the human body. Therefore, it is essential to find a stable coating with anti-adhesion properties. Summary of the Invention

[0003] This application provides a surface modification technology for surgical electrosurgical units. By using a magnetron sputtering process, a graphite-like film layer embedded with TaN particles is prepared on the surface of the surgical electrosurgical unit, which improves the anti-tissue adhesion performance of the surgical unit and maintains the surgical unit's low cytotoxicity, low electrical resistance, and suitable wear resistance.

[0004] The modification process begins by ultrasonically cleaning the surgical electrosurgical unit in acetone, anhydrous ethanol, and deionized water, followed by drying.

[0005] Inside the magnetron sputtering reaction chamber, a graphite target and a Ta target are placed opposite each other. A surgical electrosurgical sample is fixed on a rotating stage, with the handle secured and the tip exposed to the environment without obstruction. The stage speed is adjusted to 5-10 rpm, and the distance between the tip and the target is adjusted to 8-12 cm. The graphite target purity is 99.9%, and the Ta target purity is 99.9%.

[0006] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1×10⁻⁶. -4After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere.

[0007] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1-5 × 10⁻⁵. -4 Pa, heat the scalpel to 80-100℃; introduce pure argon gas at a flow rate of 50-80 sccm; set the graphite target current to 2-4A, the graphite target power supply to 150-300W, the negative bias voltage to 90-130V, and the deposition time to 50-100min to obtain a graphite-like film; then maintain the graphite target deposition parameters, introduce nitrogen gas at a flow rate of 10-15 sccm, turn on the Ta target, gradually increase the metal Ta target current from 0A to 1-1.5A, set the Ta target power supply to 50-80W, the negative bias voltage to 30-70V, and deposit for another 15-20min.

[0008] A graphite-like film embedded with TaN particles was obtained. During the deposition process, a graphite-like layer with a micro-nano structure was first obtained on the surface of the scalpel. This layer served as a transition layer, improving the overall adhesion between the film and the scalpel substrate. Subsequently, the Ta target was activated and nitrogen gas was introduced. TaN particles precipitated simultaneously with the deposition of the graphite-like material. The particles grew embedded in the surface of the graphite-like layer. Due to the short deposition time and low N2 introduction rate, the TaN growth rate was not high, and a TaN layer structure was not formed. The TaN particles were uniformly embedded in the graphite-like material and formed a micro-protrusion structure, reducing the contact area between the scalpel surface and the tissue. This surface structure gave the scalpel anti-tissue adhesion properties. Excess Ta during the deposition process did not form TaN but was dispersed as a dopant element in the graphite-like layer, improving its wear resistance and inhibiting the diffusion of harmful metal elements in the scalpel body material. Ta itself is an element with biocompatibility and bactericidal properties, and its presence can also reduce the damage of the scalpel to human tissue. Detailed Implementation

[0009] Example 1:

[0010] First, the surgical electrosurgical unit is ultrasonically cleaned and dried in acetone, anhydrous ethanol, and deionized water in sequence.

[0011] Inside the magnetron sputtering reaction chamber, a graphite target and a Ta target were placed opposite each other. A surgical electrosurgical sample was fixed on a rotating stage, with the handle secured and the tip exposed to the environment without obstruction. The stage rotation speed was adjusted to 8 rpm, and the distance between the tip and the target was adjusted to 10 cm. The graphite target purity was 99.9%, and the Ta target purity was 99.9%.

[0012] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1×10⁻⁶. -4After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere.

[0013] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 5 × 10⁻⁶. -4 Pa, the scalpel was heated to 100℃; pure argon gas was introduced at a flow rate of 80 sccm; the graphite target current was 2A, the graphite target power supply was 200W, the negative bias voltage was 100V, and the deposition time was 80min to obtain a graphite-like film; then, while maintaining the graphite target deposition parameters, nitrogen gas was introduced at a flow rate of 15 sccm, the Ta target was turned on, and the current of the metal Ta target was gradually increased from 0A to 1A, the Ta target power supply was 50W, the negative bias voltage was 50V, and deposition was carried out for another 20min.

[0014] Anti-tissue adhesion performance test: The surgical electrosurgical unit was connected to the ICC200 INT medical high-frequency power supply and a fresh pork cutting test was conducted at a power of 150W. During the test, the electrosurgical unit was used to cut the surface of the pork from left to right once, with each cut being 15cm in length. The mass of the two high-frequency electrosurgical units before and after the test was tested using an electronic balance, and the difference was calculated to obtain the mass of pork tissue adhering to the surface of the electrosurgical unit.

[0015] Conductivity test: Place the two test probes of the digital multimeter at the center of the handle and the center of the tip of the electric knife, respectively, and test the surface resistance of the electric knife.

[0016] Cytotoxicity assay: Human colorectal adenocarcinoma cells (Cao-2 cells) were used as the experimental subject. Before the experiment, Caco-2 cells were passaged and then cultured together with a scalpel. The culture dishes were placed in a cell culture incubator. Cell growth morphology was observed every two days using an inverted microscope (CK-35). The cytotoxicity of the scalpel material was tested by observing its effect on cell proliferation and cell viability. Adherent Caco-2 cells were stained for cell viability. After staining, the staining was observed using a fluorescence microscope at laser wavelengths of 490 nm and 545 nm. Live cells showed green fluorescence, and dead cells showed red fluorescence. The number of dead cells at a 1 mm × 1 mm scale was calculated.

[0017] Example 2:

[0018] First, the surgical electrosurgical unit is ultrasonically cleaned and dried in acetone, anhydrous ethanol, and deionized water in sequence.

[0019] Inside the magnetron sputtering reaction chamber, a graphite target and a Ta target were placed opposite each other. A surgical electrosurgical sample was fixed on a rotating stage, with the handle secured and the tip exposed to the environment without obstruction. The stage rotation speed was adjusted to 8 rpm, and the distance between the tip and the target was adjusted to 10 cm. The graphite target purity was 99.9%, and the Ta target purity was 99.9%.

[0020] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1×10⁻⁶. -4 After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere.

[0021] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 2×10⁻⁶. -4 Pa, the scalpel was heated to 80℃; pure argon gas was introduced at a flow rate of 80 sccm; the graphite target current was 3A, the graphite target power supply was 250W, the negative bias voltage was 120V, and the deposition time was 80min to obtain a graphite-like film; then, while maintaining the graphite target deposition parameters, nitrogen gas was introduced at a flow rate of 12 sccm, the Ta target was turned on, and the current of the metal Ta target was gradually increased from 0A to 1.5A, the Ta target power supply was 80W, the negative bias voltage was 70V, and deposition was carried out for another 15min.

[0022] Subsequently, anti-tissue adhesion properties, conductivity, and cytotoxicity were tested.

[0023] Comparative Example 1:

[0024] First, the surgical electrosurgical unit is ultrasonically cleaned and dried in acetone, anhydrous ethanol, and deionized water in sequence.

[0025] Inside the magnetron sputtering reaction chamber, a graphite target and a Ta target were placed opposite each other. A surgical electrosurgical sample was fixed on a rotating stage, with the handle secured and the tip exposed to the environment without obstruction. The stage rotation speed was adjusted to 8 rpm, and the distance between the tip and the target was adjusted to 10 cm. The graphite target purity was 99.9%, and the Ta target purity was 99.9%.

[0026] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1×10⁻⁶. -4 After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere.

[0027] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 5 × 10⁻⁶. -4Pa, the scalpel was heated to 100℃; pure argon gas was introduced at a flow rate of 80 sccm; the graphite target current was 2A, the graphite target power supply was 200W, the negative bias voltage was 100V, and the deposition time was 80min to obtain a graphite-like film; then, while maintaining the graphite target deposition parameters, nitrogen gas was introduced at a flow rate of 15 sccm, the Cr target was turned on, and the current of the metal Cr target was gradually increased from 0A to 1A, the Ta target power supply was 50W, the negative bias voltage was 50V, and deposition was carried out for another 20min.

[0028] Subsequently, anti-tissue adhesion properties, conductivity, and cytotoxicity were tested.

[0029] Comparative Example 2:

[0030] First, the surgical electrosurgical unit is ultrasonically cleaned and dried in acetone, anhydrous ethanol, and deionized water in sequence.

[0031] Inside the magnetron sputtering reaction chamber, a graphite target and a Ta target were placed opposite each other. A surgical electrosurgical sample was fixed on a rotating stage, with the handle secured and the tip exposed to the environment without obstruction. The stage rotation speed was adjusted to 8 rpm, and the distance between the tip and the target was adjusted to 10 cm. The graphite target purity was 99.9%, and the Ta target purity was 99.9%.

[0032] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1×10⁻⁶. -4 After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere.

[0033] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 5 × 10⁻⁶. -4 Pa, the scalpel was heated to 100℃; the flow rate of pure argon gas was 80 sccm; the current of the graphite target was 2A, the power of the graphite target power supply was 200W, the negative bias voltage was 100V, and the deposition time was 80min to obtain a graphite-like film layer; then, while maintaining the graphite target deposition parameters, the Ta target was turned on, and the current of the metal Ta target was gradually increased from 0A to 1A, the power of the Ta target power supply was 50W, the negative bias voltage was 50V, and the deposition time was 20min.

[0034] Subsequently, anti-tissue adhesion properties, conductivity, and cytotoxicity were tested.

[0035] Comparative Example 3:

[0036] First, the surgical electrosurgical unit is ultrasonically cleaned and dried in acetone, anhydrous ethanol, and deionized water in sequence.

[0037] Inside the magnetron sputtering reaction chamber, a graphite target and a Ta target were placed opposite each other. A surgical electrosurgical sample was fixed on a rotating stage, with the handle secured and the tip exposed to the environment without obstruction. The stage rotation speed was adjusted to 8 rpm, and the distance between the tip and the target was adjusted to 10 cm. The graphite target purity was 99.9%, and the Ta target purity was 99.9%.

[0038] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1×10⁻⁶. -4 After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere.

[0039] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 5 × 10⁻⁶. -4 Pa, the scalpel was heated to 100℃; pure argon gas was introduced at a flow rate of 80 sccm; the graphite target current was 2A, the graphite target power supply was 200W, the negative bias voltage was 100V, and the deposition time was 80min to obtain a graphite-like film; then, while maintaining the graphite target deposition parameters, nitrogen gas was introduced at a flow rate of 15 sccm, the Ta target was turned on, and the current of the metal Ta target was gradually increased from 0A to 1A, the Ta target power supply was 50W, the negative bias voltage was 50V, and deposition was carried out for another 60min.

[0040] Subsequently, anti-tissue adhesion properties, conductivity, and cytotoxicity were tested.

[0041] Comparative Example 4:

[0042] First, the surgical electrosurgical unit is ultrasonically cleaned and dried in acetone, anhydrous ethanol, and deionized water in sequence.

[0043] Inside the magnetron sputtering reaction chamber, a graphite target and a Ta target were placed opposite each other. A surgical electrosurgical sample was fixed on a rotating stage, with the handle secured and the tip exposed to the environment without obstruction. The stage rotation speed was adjusted to 8 rpm, and the distance between the tip and the target was adjusted to 10 cm. The graphite target purity was 99.9%, and the Ta target purity was 99.9%.

[0044] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1×10⁻⁶. -4 After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere.

[0045] The magnetron sputtering reaction chamber was evacuated to a vacuum level of 5 × 10⁻⁶. -4Pa, the scalpel was heated to 100℃; pure argon gas was introduced at a flow rate of 80 sccm; the graphite target current was 2A, the graphite target power supply was 200W, the negative bias voltage was 100V, and the deposition time was 80min to obtain a graphite-like film; then, while maintaining the graphite target deposition parameters, nitrogen gas was introduced at a flow rate of 50 sccm, the Ta target was turned on, and the current of the metal Ta target was gradually increased from 0A to 1A, the Ta target power supply was 50W, the negative bias voltage was 50V, and deposition was carried out for another 20min.

[0046] Subsequently, anti-tissue adhesion properties, conductivity, and cytotoxicity were tested.

[0047] The test results show that in Comparative Example 1, the absence of biocompatible Ta element led to increased biotoxicity. In Comparative Example 2, the lack of nitrogen gas resulted in the inability to form TaN micro-protrusions, and the anti-adhesion performance provided solely by the graphite-like micro-nano structure was insufficient. In Comparative Examples 2 and 3, extending the nitrogen gas flow rate or increasing the flow rate resulted in the formation of TaN film instead of micro-protrusions, leading to a decrease in both conductivity and anti-adhesion properties.

[0048] Table 1 Test Results

[0049] Adhesive tissue weight / g Resistance / Ω Number of dead cells Example 1 0.048 3.5 12 Example 2 0.054 3.8 9 Comparative Example 1 0.067 4.0 108 Comparative Example 2 0.157 3.6 15 Comparative Example 3 0.135 15.2 10 Comparative Example 4 0.143 14.3 16

Claims

1. A method for surface modification of a surgical electrosurgical unit, characterized in that, Includes the following steps: First, the surgical electrosurgical unit was ultrasonically cleaned and dried in acetone, anhydrous ethanol, and deionized water in sequence. The magnetic control chamber was evacuated to a vacuum level of 1×10⁻⁶. -4 After Pa, argon gas is introduced at a flow rate of 20 sccm to clean the scalpel under argon atmosphere. In the magnetron sputtering reaction chamber, a graphite target and a metal Ta target are placed opposite each other. A surgical electrosurgical sample is fixed on a rotating stage with the handle fixed and the tip exposed to the environment without any obstruction. The magnetron sputtering reaction chamber was evacuated to a vacuum level of 1-5 × 10⁻⁵. -4 Pa, heat the scalpel to 80-100℃; introduce pure argon gas at a flow rate of 50-80 sccm; set the graphite target current to 2-4A, the graphite target power supply to 150-300W, the negative bias voltage to 90-130V, and the deposition time to 50-100min to obtain a graphite-like film; then maintain the graphite target deposition parameters, introduce nitrogen gas at a flow rate of 10-15 sccm, turn on the Ta target, gradually increase the metal Ta target current from 0A to 1-1.5A, set the Ta target power supply to 50-80W, the negative bias voltage to 30-70V, and deposit for another 15-20min.

2. The modification method as described in claim 1, characterized in that, The graphite target has a purity of 99.9%.

3. The modification method as described in claim 1, characterized in that, The Ta target purity is 99.9%.

4. The modification method as described in claim 1, characterized in that, Adjust the rotation speed of the rotary table to 5-10 rpm.

5. The modification method as described in claim 1, characterized in that, The distance between the blade and the target should be adjusted to 8-12cm.

6. The modification method as described in claim 1, characterized in that, The graphite target has a current of 2A, a power supply of 200W, and a negative bias voltage of 100V.

7. The modification method as described in claim 1, characterized in that, The scalpel is heated to 100°C.

8. The modification method as described in claim 1, characterized in that, The target power supply is 50W with a negative bias voltage of 50V.

9. The modification method as described in claim 1, characterized in that, The nitrogen flow rate is 15 sccm.

10. The surgical electrosurgical unit obtained by the modification method according to any one of claims 1-9.