A method for testing durability of an antimicrobial coating on a medical device surface and related apparatus

Abstract

The application relates to the technical field of medical instrument performance detection, in particular to a medical instrument surface antibacterial coating durability test method and related equipment, wherein the method comprises the following steps: preparing an antibacterial coating sample of a medical instrument surface, and testing an initial antibacterial activity value of the antibacterial coating sample; performing single-factor gradient testing on the antibacterial coating sample, and obtaining a critical failure threshold value of the antibacterial coating sample under single factors; constructing a coupling sequential cycle unit, setting a stress loading intensity parameter based on the critical failure threshold value, controlling the antibacterial coating sample to cycle through the coupling sequential cycle unit multiple times based on the stress loading intensity parameter, and testing corresponding actual antibacterial activity values of the antibacterial coating sample under different cycle numbers; and calculating an antibacterial performance retention rate based on the initial antibacterial activity value and the actual antibacterial activity value, so as to complete the durability test.

Description

Technical Field

[0001] This application relates to the field of medical device performance testing technology, and in particular to a method and related equipment for testing the durability of antibacterial coatings on the surface of medical devices. Background Technology

[0002] Hospital-acquired infections are a major challenge facing global healthcare systems, and bacterial biofilm formation on the surfaces of medical devices is one of the core contributing factors. Antimicrobial coatings, by constructing an antibacterial and bactericidal functional layer on the surface of medical devices, can effectively inhibit bacterial colonization and reduce the risk of infection, and have been widely used in various medical devices such as surgical instruments, endoscopes, implants, and diagnostic and treatment equipment.

[0003] The core requirement for the clinical application of antimicrobial coatings is antimicrobial durability, meaning that the coating should maintain stable antimicrobial properties throughout the entire lifecycle of the medical device, after being subjected to mechanical friction, chemical disinfection, sterilization, and environmental aging. Currently, industry testing for the durability of antimicrobial coatings largely references conventional durability testing methods for coatings and plastics. This primarily involves independent single-factor tests across four dimensions: mechanical durability, chemical stability, thermal stability, and aging resistance. After each single-factor test, antimicrobial performance is tested according to ISO 22196 or JIS Z 2801 standards, and the antimicrobial performance retention rate is calculated.

[0004] The relevant technologies suffer from the following unresolved core defects: 1. Severe disconnect from actual clinical application scenarios, resulting in extremely low prediction accuracy: In clinical practice, the antibacterial coating of medical devices undergoes a series of coupled stresses throughout its lifespan, including mechanical friction, chemical disinfection, moist heat sterilization, and environmental aging. For example, reusable surgical instruments undergo a complete process of "intraoperative friction and scraping - postoperative disinfectant wiping - high-pressure steam sterilization - storage aging" with each use. The coupled effects of these multiple stresses create a vicious cycle of "accelerated damage - antibacterial agent loss - performance degradation," significantly accelerating coating failure. Current technologies use single-factor independent testing, which cannot recreate the actual failure process caused by multi-stress coupling. This leads to coatings that pass laboratory tests failing rapidly in clinical use, with test results matching actual clinical failure behavior in less than 40% of cases.

[0005] 2. Only post-event evaluation is possible, and failure early warning and quantitative prediction are not possible: Existing technologies only evaluate whether the coating has failed by testing the antibacterial rate after stress treatment. They cannot establish a quantitative correlation between coating micro-damage and antibacterial performance degradation, cannot predict the degradation trend of antibacterial performance in advance by detecting coating micro-damage, and cannot achieve failure early warning. They cannot provide data support for coating formulation optimization and medical device service life determination.

[0006] 3. Lack of a unified grading and evaluation system, resulting in low screening efficiency: Existing technologies do not have corresponding durability grading thresholds for medical devices in different clinical application scenarios, making it impossible to quickly screen out antibacterial coating products suitable for the target scenario. This leads to long coating development cycles, high screening costs, and an inability to achieve rapid evaluation on a large scale.

[0007] 4. Inconsistent test parameters, poor repeatability and comparability: The parameter settings of existing test methods do not correspond to clinical scenarios, and the test conditions of different laboratories vary greatly, resulting in poor repeatability and comparability of test results, and making it impossible to form a unified evaluation standard in the industry. Summary of the Invention

[0008] The main objective of this application is to provide a method and related equipment for testing the durability of antibacterial coatings on the surface of medical devices, in order to solve the problems in the background art.

[0009] To achieve the above objectives, one aspect of this application provides a method for testing the durability of an antibacterial coating on a medical device surface, the method comprising: Prepare an antibacterial coating sample for the surface of a medical device, and test the initial antibacterial activity value of the antibacterial coating sample; A single-factor gradient test was performed on the antibacterial coating sample to obtain the critical failure threshold of the antibacterial coating sample under single-factor conditions. A coupled sequential cyclic unit is constructed, and a stress loading intensity parameter is set based on the critical failure threshold. The antibacterial coating sample is controlled to cycle the coupled sequential cyclic unit multiple times based on the stress loading intensity parameter, and the actual antibacterial activity value of the antibacterial coating sample at different number of cycles is tested. The antibacterial performance retention rate is calculated based on the initial antibacterial activity value and the actual antibacterial activity value, and the durability test is completed.

[0010] In some embodiments, the method further includes: After preparing an antibacterial coating sample for the surface of a medical device, the initial microscopic damage parameters of the antibacterial coating sample are tested. The actual microscopic damage parameters of the antibacterial coating sample were tested at different cycles. Using the micro-damage parameter as the independent variable, the predicted antibacterial performance retention rate and failure cycle number of the antibacterial coating sample are output through the quantitative correlation model of antibacterial performance decay. The micro-damage parameter is the difference between the actual micro-damage parameter and the initial micro-damage parameter. Based on the predicted antibacterial performance retention rate and the number of failure cycles, the antibacterial coating samples are classified into durability grades according to a preset durability grading threshold.

[0011] In some embodiments, the preparation of the antibacterial coating sample on the surface of the medical device specifically includes: Prepare negative control samples with the same substrate as the surface of the medical device and without antibacterial coating; The initial microscopic damage parameters of the antibacterial coating sample were tested using a surface morphology analyzer, laser confocal microscope, and X-ray photoelectron spectroscopy. The initial antimicrobial activity value of the antimicrobial coating sample was tested according to ISO 22196 or JIS Z 2801 standards.

[0012] In some embodiments, the expressions for the initial antibacterial activity value and the actual antibacterial activity value are: ; in This refers to the initial antibacterial activity value or the actual antibacterial activity value. This represents the average viable bacterial count of the negative control sample after 24 hours. The average number of viable bacteria after 24 hours.

[0013] In some embodiments, both the initial micro-damage parameters and the actual micro-damage parameters include surface roughness, maximum scratch depth, and relative residual rate of antibacterial agent, and the expression for the predicted antibacterial performance retention rate is: ; in To predict the retention rate of antibacterial properties, , , , , , as well as All are preset weights. For random error term, This represents the surface roughness increment. For the maximum scratch depth increment, This represents the relative residual rate of antibacterial agents.

[0014] In some embodiments, performing a single-factor gradient test on the antibacterial coating sample to obtain the critical failure threshold of the antibacterial coating sample under a single factor specifically includes: Set gradient stress loading parameters, use the Taber abrasion tester method or grinding wheel abrasion method to test the abrasion resistance of the sample, use constant load scratch test or cross-cut test to test the coating adhesion and scratch resistance of the sample, and obtain the critical failure threshold of the antibacterial coating sample under mechanical durability test. The gradient wiping cycle number is set, and the robotic arm automatic cyclic wiping method is used to obtain the critical failure threshold of the antibacterial coating sample under chemical stability test. The gradient thermal cycle number was set, and the temperature and humidity alternating cycle test was carried out by the saturated steam sterilization cycle method to obtain the critical failure threshold of the antibacterial coating sample under the thermal stability test. By setting gradient exposure times and using ultraviolet accelerated aging or ozone exposure aging tests, the critical failure threshold of the antibacterial coating sample under accelerated aging tests is obtained.

[0015] In some embodiments, after controlling the antibacterial coating sample to cycle the coupled sequential cyclic unit multiple times based on the stress loading intensity parameter, the method further includes: Determine the difference between the number of iterations and the preset gradient iteration count; When the difference is lower than the loop threshold, the loop terminates and outputs the actual antibacterial activity value, the actual microscopic damage parameters, and the performance degradation dataset, which includes the surface roughness increment, the maximum scratch depth increment, and the relative residual rate of the antibacterial agent.

[0016] In some embodiments, after outputting the predicted antibacterial performance retention rate and failure cycle number of the antibacterial coating sample through a quantitative correlation model of antibacterial performance decay, the method further includes: Calculate the validation value, lack-of-fit term, and coefficient of determination of the quantitative correlation model for the degradation of antibacterial performance; The check value, the lack of fit term, and the coefficient of determination are compared with their respective preset thresholds. When the verification value is less than the corresponding preset threshold, and the lack of fit term and the coefficient of determination are greater than the corresponding preset threshold, the predicted antibacterial performance retention rate is retained. When the verification value is greater than the corresponding preset threshold, and the lack of fit and the coefficient of determination are less than the corresponding preset threshold, the predicted antibacterial performance retention rate is removed.

[0017] To achieve the above objectives, another aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0018] To achieve the above objectives, another aspect of the embodiments of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0019] The embodiments of this application include at least the following beneficial effects: This application provides a method and related equipment for testing the durability of antibacterial coatings on the surface of medical devices. By constructing a coupled sequential cyclic unit, the coating failure process under multiple stress coupling in clinical practice is restored. Moreover, the parameters of the coupled sequential cyclic unit can be flexibly customized according to the clinical scenario of the target medical device, and can be adapted to various types of medical devices. This application establishes a quantitative correlation model for antibacterial performance decay. By non-destructively detecting the microscopic damage of the coating, it directly predicts the antibacterial performance retention rate and anticipates the failure threshold in advance. This not only significantly improves the coating screening efficiency but also provides accurate data support for the formulation of safe use cycles for medical devices and the optimization of coating formulations, filling the technical gap in the industry for quantitative prediction of antibacterial durability. The durability classification of antimicrobial coating samples clarifies the corresponding medical device types for each level, enabling rapid and accurate screening of antimicrobial coatings for different scenarios. This significantly shortens the R&D cycle of antimicrobial coatings, reduces screening costs, and provides the industry with a unified evaluation standard, improving the repeatability and comparability of test results. Attached Figure Description

[0020] Figure 1 Flowchart of the method for testing the durability of antibacterial coatings on the surface of medical devices provided in this application embodiment; Figure 2 A schematic diagram of the method for testing the durability of antibacterial coatings on the surface of medical devices provided in this application embodiment; Figure 3 The flowchart of a single-coupled sequential loop unit provided in the embodiments of this application is shown. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0022] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if” or “when” as used herein may be interpreted as “when…” or “in response to determination.”

[0023] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0025] Before providing a detailed description of the embodiments of this application, some of the nouns and terms involved in the embodiments of this application will be explained first. The nouns and terms involved in the embodiments of this application are subject to the following interpretations.

[0026] ASTM D4060 (Standard Test Method for Abrasion Resistance of Organic Coatings by the Taber Abraser) is a standard test method for determining the abrasion resistance of organic coatings using the Taber Abraser abrasion tester.

[0027] ASTM D3359 (Standard Test Methods for Measuring Adhesion by TapeTest) is a standard test method for measuring the adhesion of adhesive tape.

[0028] ISO 17665-1 is a standard developed by the International Organization for Standardization (ISO) for the development, validation and routine control of moist heat sterilization processes for medical devices.

[0029] ASTM G154 is an internationally recognized test method that uses fluorescent ultraviolet lamps to expose materials to ultraviolet (UV) radiation, simulating the effects of destructive UV energy, high temperature, and long-term moisture immersion on materials in outdoor environments, thereby evaluating the accelerated aging performance of materials.

[0030] ISO 22196, "Measurement of antimicrobial activity of plastics and other nonporous surfaces", is published by the International Organization for Standardization and is universally applicable worldwide. JIS Z 2801, "Antibacterial processed products - Test methods for antibacterial properties and determination of antibacterial effects", was formulated by the Japanese Industrial Standards Survey Committee.

[0031] refer to Figures 1-2 As shown, one aspect of this application embodiment proposes a method for testing the durability of antibacterial coatings on the surface of medical devices, the method comprising: S101: Prepare an antibacterial coating sample for the surface of a medical device and test the initial antibacterial activity value of the antibacterial coating sample; S102: Perform a single-factor gradient test on the antibacterial coating sample to obtain the critical failure threshold of the antibacterial coating sample under single-factor conditions; S103: Construct a coupled sequential cyclic unit, set the stress loading intensity parameter based on the critical failure threshold, control the antibacterial coating sample to cycle the coupled sequential cyclic unit multiple times based on the stress loading intensity parameter, and test the actual antibacterial activity value of the antibacterial coating sample at different number of cycles. S104: Calculate the antibacterial performance retention rate based on the initial antibacterial activity value and the actual antibacterial activity value, and complete the durability test.

[0032] Specifically, in step S101, the antibacterial coating sample is a sample that is completely consistent with the substrate, coating formula and preparation process of the target medical device finished product. When preparing the antibacterial coating sample, a negative control sample with the same substrate as the surface of the medical device but without antibacterial coating is prepared simultaneously. Specifically, step S101 further includes testing the initial antibacterial activity of the antibacterial coating sample, wherein the initial antibacterial activity includes the initial antibacterial activity value and the initial antibacterial activity retention rate.

[0033] In some other embodiments, the initial antimicrobial performance retention rate is set to 100%.

[0034] The initial antibacterial activity value was obtained by testing according to ISO 22196 or JIS Z 2801 standards.

[0035] Specifically, step S102 includes: Mechanical durability test: Set gradient stress loading parameters: CS-10 grinding wheel, load 500g, rotation speed 60r / min, set gradient rotation speeds of 50r, 100r, 500r, 1000r, and 2000r; The coating adhesion (refer to ASTM D3359 standard) and scratch resistance (refer to ISO 1518 standard) of the samples were tested using constant load scratch test (refer to ASTM D4060 standard) or cross-cut adhesion test. The critical failure rotation was measured to be 1200 revolutions (antibacterial activity value < 2.0). After 100 revolutions, the antibacterial performance retention rate was 96.2%, which meets the single cycle stress requirement. Chemical stability test: Set the gradient wiping cycle number: load 5N, wiping stroke 100mm, frequency 30 times / min, set gradient cycles of 10, 50, 100, 500, and 1000 times; Using an automated cyclic wiping method with a robotic arm, the critical failure cycle count was measured to be 600 cycles. After 20 cycles, the antibacterial performance retention rate was 97.1%, which meets the single-cycle stress requirement.

[0036] Thermal stability test (performed in accordance with ISO 17665-1 standard): Set the number of gradient thermal cycles: 15 minutes is one cycle, set the gradient cycles to 1, 5, 10, 20 and 50 times; The temperature and humidity alternating cycle test was carried out using the saturated steam sterilization cycle method. The critical failure cycle number was measured to be 35 cycles. After one cycle, the antibacterial performance retention rate was 98.5%, which meets the single cycle stress requirement.

[0037] Accelerated aging test (conducted in accordance with ASTM G154 standard): set gradient exposure time: irradiance 0.89W / (m²·nm), 4h of UV irradiation at 60℃ as one cycle, set gradient cycles of 1, 3, 5, 10 and 20 times. Using UV accelerated aging or ozone exposure aging tests, the antibacterial performance retention rate was 99.2% after one cycle, which meets the single-cycle stress requirements.

[0038] In this application, the gradient cycle number is set to at least 5 gradients, including 0, 10, 50, 100, and 200 times. After each specified number of cycles is completed, the sample is rinsed 3 times with sterile deionized water, dried in a sterile environment, and then antibacterial performance test and micro-damage parameter test are carried out simultaneously.

[0039] refer to Figure 3 As shown, specifically, the coupling sequential loop unit in step S103 is customized for clinical scenarios based on reusable surgical instruments, wherein the single coupling sequential loop unit includes: 1. Mechanical stress loading: Taber abrasion tester, 500g load, 100r; 2. Chemical disinfection stress loading: robotic arm wiping, alternating wiping with 75% ethanol + 1000mg / L sodium hypochlorite, 20 cycles; 3. Moist heat sterilization stress loading: 121℃ saturated steam sterilization for 15 min; 4. Environmental aging stress loading: UVA-340 ultraviolet irradiation for 4 hours; Completing the above four steps constitutes one sequential cycle, simulating one complete clinical use process.

[0040] Set the gradient cycle count: 0, 10, 30, 50, 70, 100 times. After each specified number of cycles, sample and test the actual antibacterial activity value and the actual microscopic damage parameter.

[0041] Test results showed that after 50 cycles, the antibacterial activity values ​​R were 4.5 (Staphylococcus aureus) and 4.1 (E. coli), with antibacterial performance retention rates of 86.5% and 85.4%, respectively, meeting the Class II high durability requirements; after 70 cycles, the antibacterial activity value was still ≥3.8, with an antibacterial performance retention rate of ≥79%; after 100 cycles, the antibacterial activity value dropped to 1.8, reaching the critical failure threshold.

[0042] Specifically, in step S104, the expression for the actual antibacterial activity value is: ; in This refers to the initial or actual antibacterial activity value of the antibacterial coating sample. This represents the average viable bacterial count of the negative control sample after 24 hours. The average viable count of the antibacterial coating sample after 24 hours.

[0043] The antibacterial performance retention rate is preferentially calculated using the antibacterial activity value, and the calculation formula is as follows: ; in, This represents the initial antibacterial activity value of the antibacterial coating sample. This represents the actual antibacterial activity value of the sample after stress treatment.

[0044] refer to Figure 2 As shown, further, in some embodiments, the method of this application also includes: S201: After preparing an antibacterial coating sample for the surface of a medical device, test the initial microscopic damage parameters of the antibacterial coating sample. S202: Test the actual microscopic damage parameters of the antibacterial coating sample under different cycles; S203: Using the micro-damage parameter as the independent variable, the predicted antibacterial performance retention rate and failure cycle number of the antibacterial coating sample are output through the quantitative correlation model of antibacterial performance decay. The micro-damage parameter is the difference between the actual micro-damage parameter and the initial micro-damage parameter. S204: Based on the predicted antibacterial performance retention rate and failure cycle count, the antibacterial coating sample is classified into durability grades according to a preset durability grading threshold.

[0045] Specifically, the initial microscopic damage parameters in step S201 are obtained by testing with a surface morphology analyzer, a laser confocal microscope, and an X-ray photoelectron spectroscopy analyzer.

[0046] It should be understood that steps S102 and 103 of this application can obtain measured data of antibacterial performance under a limited number of discrete cycles through single-factor gradient testing and multi-factor coupled sequential loop testing.

[0047] Based on steps S102 and 103, this application constructs a quantitative correlation model for antibacterial performance degradation, using microscopic damage parameters as independent variables, to predict the antibacterial performance retention rate as the response value, and establishes a functional relationship between the two through multivariate regression fitting. Using this model, on the one hand, interpolation prediction can be performed on the unmeasured cycle number in S3, filling the gaps in the measured data; on the other hand, the number of cycles corresponding to the first time the antibacterial performance retention rate falls below a preset failure threshold can be extrapolated and calculated, thereby quantitatively outputting the coating's failure threshold and predicted life-cycle durability.

[0048] This method achieves a technological leap from "post-test evaluation" to "pre-test prediction and early warning" through a quantitative correlation model of antibacterial performance decay. It reduces the experimental workload of subsequent product screening and durability rating, and provides quantifiable failure criteria. As long as the microscopic damage parameters after any number of cycles are measured, the corresponding antibacterial performance can be calculated instantly, thereby achieving performance prediction at any time point and filling the gap between measured data.

[0049] Specifically, both the initial micro-damage parameters and the actual micro-damage parameters include surface roughness, maximum scratch depth, and relative residual rate of antibacterial agent. The expression for the predicted antibacterial performance retention rate is as follows: ; in To predict the retention rate of antibacterial properties, , , , , , as well as All are preset weights. For random error term, This represents the surface roughness increment. For the maximum scratch depth increment, This represents the relative residual rate of antibacterial agents.

[0050] Specifically, step S204 involves classifying the antibacterial coating sample into durability grades, including: Level I - Ultra-long durability: After completing ≥100 sequential cycles, the antibacterial activity value is ≥2.0, and the antibacterial performance retention rate is ≥90%, making it suitable for implantable medical devices and high-value reusable surgical instruments; Level II - High Durability: After completing ≥50 sequential cycles, the antibacterial activity value is ≥2.0, and the antibacterial performance retention rate is ≥85%, making it compatible with conventional reusable surgical instruments and core diagnostic and treatment instruments in the operating room; Level III - Medium Durability: After completing ≥10 sequential cycles, the antibacterial activity value is ≥2.0, and the antibacterial performance retention rate is ≥80%. It is suitable for general outpatient medical devices and disposable high-risk medical devices. Grade IV - Low Durability: Does not meet Grade III requirements, deemed unqualified, and cannot be used for antibacterial coatings on medical device surfaces.

[0051] The following examples illustrate this application: Scenario 1: Durability test of antibacterial coating on reusable stainless steel surgical instruments The test subject was a 316L stainless steel surface with a silver-impregnated antibacterial coating. The target application was reusable surgical instruments for abdominal surgery, with a clinical requirement of ≥50 reuses. The specific test methods included: S1 Sample Preparation and Benchmark Performance Testing 316L stainless steel samples measuring 100mm × 100mm × 2mm were prepared. A silver-loaded antibacterial coating was prepared using the same process as the finished product. Six parallel samples were prepared in each group. Simultaneously, negative control samples of the same size without antibacterial coating were prepared. The samples were conditioned for 24 hours in an environment of 23℃ ± 2℃ and 50% ± 5% relative humidity.

[0052] Initial antimicrobial performance testing: According to ISO 22196 standard, the test strains were Staphylococcus aureus ATCC6538 and Escherichia coli ATCC8739. The initial antimicrobial activity values ​​R were measured to be 5.2 and 4.8, respectively, and the initial antimicrobial rates were both >99.99%. At the same time, the initial antimicrobial performance retention rate was determined to be 100%.

[0053] The initial surface roughness Ra was measured to be 0.082 μm using a white light interferometer; the maximum scratch depth D0 of the initial coating was measured to be 0 μm (no scratch) using a laser confocal microscope; and the relative silver content M of the initial surface was measured to be 2.35% using an X-ray photoelectron spectroscopy (XPS) instrument.

[0054] S2 Single-Factor Gradient Pretest Single-factor gradient tests were performed in four dimensions to obtain the critical failure thresholds: S2.1 Mechanical durability test: A Taber abrasion tester was used with a CS-10 grinding wheel, a load of 500g, and a rotation speed of 60r / min. Gradient rotation speeds of 50r, 100r, 500r, 1000r, and 2000r were set. The critical failure rotation speed was measured to be 1200r (antibacterial activity value < 2.0). After 100r cycles, the antibacterial performance retention rate was 96.2%, which meets the single-cycle stress requirements.

[0055] S2.2 Chemical Stability Test: An automated wiping tester with a robotic arm was used. The test medium was 75% ethanol + 1000 mg / L sodium hypochlorite solution (alternating wiping). The load was 5 N, the wiping stroke was 100 mm, and the frequency was 30 times / min. Gradient cycles of 10, 50, 100, 500, and 1000 were set. The critical failure cycle count was measured to be 600 cycles. After 20 cycles, the antibacterial performance retention rate was 97.1%, which meets the single-cycle stress requirement.

[0056] S2.3 Thermal stability test: Sterilization was performed using saturated steam at 121℃ and 0.1MPa, with each cycle lasting 15 minutes. Gradient cycles of 1, 5, 10, 20, and 50 cycles were set. The critical failure cycle count was measured to be 35 cycles. After one cycle, the antibacterial performance retention rate was 98.5%, which meets the single-cycle stress requirement.

[0057] S2.4 Accelerated Aging Test: A UVA-340 ultraviolet aging test chamber was used, with an irradiance of 0.89 W / (m²·nm). One cycle consisted of 4 hours of UV irradiation at 60℃. Gradient cycles of 1, 3, 5, 10, and 20 were set. The antibacterial performance retention rate after one cycle was measured to be 99.2%, meeting the single-cycle stress requirements.

[0058] S3 Multi-Factor Coupled Sequential Loop Unit Test Based on the clinical scenario of reusable surgical instruments, a sequential cycle unit is customized, with the following steps in a single cycle: Mechanical stress loading: Taber abrasion tester, 500g load, 100r; Chemical disinfection stress loading: robotic arm wiping, alternating wiping with 75% ethanol + 1000mg / L sodium hypochlorite, 20 cycles; Moist heat sterilization stress loading: 121℃ saturated steam sterilization for 15 min; Environmental aging stress loading: UVA-340 ultraviolet irradiation for 4 hours; Completing the above four steps constitutes one sequential cycle, simulating one full clinical use process.

[0059] Set the gradient cycle count: 0, 10, 30, 50, 70, 100 times. After each specified number of cycles, sample and test the actual antibacterial activity value and the actual microscopic damage parameter.

[0060] Test results showed that after 50 cycles, the actual antibacterial activity values ​​R were 4.5 (Staphylococcus aureus) and 4.1 (E. coli), with antibacterial performance retention rates of 86.5% and 85.4%, respectively, meeting the Class II high durability requirements; after 70 cycles, the actual antibacterial activity value was still ≥3.8, with an antibacterial performance retention rate of ≥79%; after 100 cycles, the antibacterial activity value dropped to 1.8, reaching the critical failure threshold.

[0061] S4 Durability Quantitative Prediction Model Construction obtained from testing , , With Y as the antibacterial performance retention rate and Y as the response value, a quantitative correlation model was obtained by fitting the data. ; The results of the model variance analysis showed that the model validation value was <0.0001, which was highly significant; the lack-of-fit term P=0.2365>0.05, indicating a good fit; and the coefficient of determination R²=0.9872, indicating that the model was reliable.

[0062] Model validation values ​​are statistics constructed based on the ratio of the regression mean square to the residual mean square, used to test whether the overall regression equation is significant. A p-value < 0.05 for the lack-of-fit term only indicates the probability that "the model is statistically significant." The p-value for the lack-of-fit term is a statistic constructed based on the ratio of the lack-of-fit mean square to the pure error mean square, used to test whether the model has systematic underfitting. A p-value > 0.05 indicates that "the model has not shown significant lack of fit," rather than a lack-of-fit term value greater than 0.05. The R in the coefficient of determination R² (≥ 0.95) is the multiple correlation coefficient in statistics. The model predicts that the coating's critical failure point is 92 cycles, with a deviation of less than 10% from the actual test results, demonstrating extremely high prediction accuracy.

[0063] S5 Durability Grading Evaluation and Screening Based on the test results and model predictions, the coating has an antibacterial activity value of ≥2.0 and an antibacterial performance retention rate of ≥85% after 50 cycles. It is classified as Grade II - High Durability, meets the clinical use requirements of reusable surgical instruments, and is qualified for screening.

[0064] Scenario 2: Durability Test of Antibacterial Coating for Orthopedic Implants The test subject in this scenario is the polydopamine-gentamicin antibacterial coating on the surface of titanium alloy, and the target application scenario is orthopedic implants, with clinical requirements for in vivo service durability ≥1 year.

[0065] This testing method is an adjustment based on Scenario 1, specifically as follows: 1. The sequential circulation unit adapts to implant scenarios, adding a simulated body fluid immersion process and removing the disinfectant wiping process; 2. Accelerated aging tests have been expanded to include neutral salt spray testing and 37°C simulated body fluid immersion testing; 3. The durability rating requirement is Level I - Ultra-long-lasting durability.

[0066] Test results showed that after 100 sequential cycles, the antibacterial activity value of the coating was ≥4.2, and the antibacterial performance retention rate was ≥92%, which was judged as Grade I - ultra-long durability, meeting the clinical requirements of orthopedic implants. The model predicted that the coating could still maintain effective antibacterial performance after 18 months of in vivo service, with a match rate of ≥91% with the animal experimental results.

[0067] In this scenario, the existing single-factor independent testing method was used to test the same batch of silver-loaded antibacterial coatings. Single-factor tests were performed for Taber abrasion resistance 500r, disinfectant wiping 100 times, sterilization 50 times, and UV aging 200h. The test results showed that the antibacterial activity value was ≥2.5 after each single-factor test, and the antibacterial performance retention rate was ≥80%, which was judged as qualified.

[0068] However, clinical follow-up trials showed that after 42 clinical reuses, the antibacterial activity value of the coating dropped to 1.7, losing its effective antibacterial ability and resulting in clinical failure. The matching degree between the traditional single-factor test results and the actual clinical failure behavior was only 38%, far lower than the matching degree of ≥90% in Example 1 of this invention, fully demonstrating the outstanding technical effect of this invention.

[0069] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0070] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0071] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0072] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0073] The methods provided in this application relate to the field of information technology. The methods provided in this application can be applied to terminals, servers, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, smart speaker, smartwatch, or in-vehicle terminal, but is not limited to these. The server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network. The software can be an application implementing the method, but is not limited to the above forms.

[0074] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0075] It should be noted that in all specific embodiments of this application, when processing data related to user identity or characteristics, such as user information, user behavior data, user historical data, and user location information, user permission or consent is obtained first. Furthermore, the collection, use, and processing of this data comply with relevant laws, regulations, and standards. In addition, when embodiments of this application require access to sensitive personal information of users, separate permission or consent from the user is obtained through pop-ups or redirection to confirmation pages. Only after obtaining the user's separate permission or consent is the necessary user-related data required for the proper functioning of these embodiments acquired.

[0076] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0077] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0078] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0079] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0080] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0081] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0082] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0083] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0084] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for testing the durability of antibacterial coatings on the surface of medical devices, characterized in that, The method includes: Prepare an antibacterial coating sample for the surface of a medical device, and test the initial antibacterial activity value of the antibacterial coating sample; A single-factor gradient test was performed on the antibacterial coating sample to obtain the critical failure threshold of the antibacterial coating sample under single-factor conditions. A coupled sequential cyclic unit is constructed, and a stress loading intensity parameter is set based on the critical failure threshold. The antibacterial coating sample is controlled to cycle the coupled sequential cyclic unit multiple times based on the stress loading intensity parameter, and the actual antibacterial activity value of the antibacterial coating sample at different number of cycles is tested. The antibacterial performance retention rate is calculated based on the initial antibacterial activity value and the actual antibacterial activity value, and the durability test is completed.

2. The method for testing the durability of antibacterial coatings on medical device surfaces according to claim 1, characterized in that, The method further includes: After preparing an antibacterial coating sample for the surface of a medical device, the initial microscopic damage parameters of the antibacterial coating sample are tested. The actual microscopic damage parameters of the antibacterial coating sample were tested at different cycles. Using the micro-damage parameter as the independent variable, the predicted antibacterial performance retention rate and failure cycle number of the antibacterial coating sample are output through the quantitative correlation model of antibacterial performance decay. The micro-damage parameter is the difference between the actual micro-damage parameter and the initial micro-damage parameter. Based on the predicted antibacterial performance retention rate and the number of failure cycles, the antibacterial coating samples are classified into durability grades according to a preset durability grading threshold.

3. The method for testing the durability of antibacterial coatings on medical device surfaces according to claims 1-2, characterized in that, After preparing the antibacterial coating sample for the surface of the medical device, the method further includes: Prepare negative control samples with the same substrate as the surface of the medical device and without antibacterial coating; The initial microscopic damage parameters of the antibacterial coating sample were tested using a surface morphology analyzer, laser confocal microscope, and X-ray photoelectron spectroscopy. The initial antimicrobial activity value of the antimicrobial coating sample was tested according to ISO 22196 or JIS Z 2801 standards.

4. The method for testing the durability of antibacterial coatings on medical device surfaces according to claim 1, characterized in that, The expressions for the initial antibacterial activity value and the actual antibacterial activity value are as follows: ； in This refers to the initial or actual antibacterial activity value of the antibacterial coating sample. This represents the average viable bacterial count of the negative control sample after 24 hours. The average viable count of the antibacterial coating sample after 24 hours.

5. The method for testing the durability of antibacterial coatings on medical device surfaces according to claim 2, characterized in that, Both the initial and actual micro-damage parameters include surface roughness, maximum scratch depth, and relative antibacterial agent residue rate. The expression for the predicted antibacterial performance retention rate is as follows: ； in To predict the retention rate of antibacterial properties, , , , , , as well as All are preset weights. For random error term, This represents the surface roughness increment. For the maximum scratch depth increment, This represents the relative residual rate of antibacterial agents.

6. The method for testing the durability of antibacterial coatings on medical device surfaces according to claim 1, characterized in that, The step of performing a single-factor gradient test on the antibacterial coating sample to obtain the critical failure threshold of the antibacterial coating sample under a single factor specifically includes: Set gradient stress loading parameters, use the Taber abrasion tester method or grinding wheel abrasion method to test the abrasion resistance of the sample, use constant load scratch test or cross-cut test to test the coating adhesion and scratch resistance of the sample, and obtain the critical failure threshold of the antibacterial coating sample under mechanical durability test. The gradient wiping cycle number is set, and the robotic arm automatic cyclic wiping method is used to obtain the critical failure threshold of the antibacterial coating sample under chemical stability test. The gradient thermal cycle number was set, and the temperature and humidity alternating cycle test was carried out by the saturated steam sterilization cycle method to obtain the critical failure threshold of the antibacterial coating sample under the thermal stability test. By setting gradient exposure times and using ultraviolet accelerated aging or ozone exposure aging tests, the critical failure threshold of the antibacterial coating sample under accelerated aging tests is obtained.

7. The method for testing the durability of antibacterial coatings on medical device surfaces according to claim 1, characterized in that, After controlling the antibacterial coating sample to cycle multiple times using the coupled sequential cyclic unit based on the stress loading intensity parameter, the method further includes: Determine the difference between the number of iterations and the preset gradient iteration count; When the difference is lower than the loop threshold, the loop terminates and outputs the actual antibacterial activity value, the actual microscopic damage parameters, and the performance degradation dataset, which includes the surface roughness increment, the maximum scratch depth increment, and the relative residual rate of the antibacterial agent.

8. The method for testing the durability of antibacterial coatings on medical device surfaces according to claim 2, characterized in that, After outputting the predicted antibacterial performance retention rate and failure cycle number of the antibacterial coating sample through the quantitative correlation model of antibacterial performance decay, the method further includes: Calculate the validation value, lack-of-fit term, and coefficient of determination of the quantitative correlation model for the degradation of antibacterial performance; The check value, the lack of fit term, and the coefficient of determination are compared with their respective preset thresholds. When the verification value is less than the corresponding preset threshold, and the lack of fit term and the coefficient of determination are greater than the corresponding preset threshold, the predicted antibacterial performance retention rate is retained. When the verification value is greater than the corresponding preset threshold, and the lack of fit and the coefficient of determination are less than the corresponding preset threshold, the predicted antibacterial performance retention rate is removed.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method according to any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 8.

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