A method for preparing a film coating for obstetric forceps

Abstract

The application relates to the technical field of medical devices, in particular to a preparation method of a delivery forceps film layer for obstetrics, which comprises the following steps: carrying out plasma immersion ion implantation and deposition treatment on the surface of a delivery forceps base body; preparing a composite coating solution, obtaining a comprehensive quality evaluation value of the solution, and judging the passability of the composite coating solution; adjusting the parameters of the composite coating solution based on the nanometer particle stability index of the solution after standing for a preset time length; depositing the qualified composite coating solution on the surface of the base body through an atomization spraying mode; carrying out programmed curing on the deposited film layer, and carrying out micro-nano texture processing and hydrophilic modification on the surface of the film layer, so that the preparation of the film layer is completed; obtaining a film layer performance evaluation value, and judging the passability of the film layer preparation based on the comparison result of the film layer performance evaluation value and a preset performance evaluation value. The interface bonding force of the surface of the base body and the surface of the film layer is enhanced, so that the mechanical durability and service life of the delivery forceps film layer are improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a method for preparing a diaphragm layer for obstetric forceps. Background Technology

[0002] As a key obstetric instrument, forceps play an irreplaceable role in resolving dystocia, shortening the second stage of labor, and reducing the cesarean section rate. Traditional forceps, often made of metal (such as stainless steel), come into direct contact with the fetal head and maternal birth canal. This presents several significant problems during traction: First, direct friction between the metal surface and tissues increases the risk of fetal scalp injury, hematoma, or intracranial hemorrhage, while potentially causing maternal tearing of the birth canal, mucosal damage, and increased postoperative pain. Second, the high hardness of the metal material is incompatible with the mechanical properties of tissues, potentially affecting the fetal skull's natural deformability due to uneven pressure distribution during operation. Third, even sterile metal surfaces can become potential sites for pathogen colonization due to minor scratches during operation. Therefore, a coating layer needs to be prepared on the surface of the forceps to reduce problems such as fetal head injury caused by excessive clamping force.

[0003] Chinese Patent Application Publication No. CN110051413A discloses a delivery forceps for obstetrics and a method for preparing a coating layer for the delivery forceps. The delivery forceps for obstetrics includes a forceps body, forceps blades located at the front end of the forceps body for enclosing the fetal head, and forceps handles located at the rear end of the forceps body. The inner surface of the forceps blades is provided with a coating layer made of polydimethylsiloxane / hydrophilic silica polymer nanocomposite material. The coating layer is prepared by solution preparation, internal mold treatment, and compression molding.

[0004] However, the existing technology has the following problems: under long-term, harsh clinical use and sterilization cycle conditions, the structural integrity and functionality of the coating layer prepared by the existing technology cannot be reliably guaranteed, and there is a hidden danger that the clinical safety risk may increase due to mechanical damage or performance degradation of the coating layer. Summary of the Invention

[0005] Therefore, the present invention provides a method for preparing a forceps covering layer for obstetric use, in order to overcome the problems of insufficient mechanical durability and inability to maintain functionality of the covering layer in the prior art.

[0006] To achieve the above objectives, the present invention provides a method for preparing a forceps covering layer for obstetric use, comprising:

[0007] Step S1: Plasma immersion ion implantation and deposition treatment is performed on the surface of the midwifery forceps substrate after precision cleaning and activation to form a gradient-strengthened transition layer with preset parameters.

[0008] Step S2: Prepare a composite coating solution, and use a rheometer and a dynamic light scattering instrument to detect the viscosity and nanoparticle dispersion of the solution online to obtain a comprehensive quality evaluation value of the solution, and determine the qualification of the composite coating solution based on the comprehensive quality evaluation value.

[0009] Step S3: Under the condition that the composite coating solution is unqualified, adjust the parameters of the composite coating solution based on the comparison results of the nanoparticle stability index after the solution has been left to stand for a preset time and the preset stability index, including increasing the ultrasonic power or decreasing the solution temperature.

[0010] Step S4: Deposit the qualified composite coating solution onto the substrate surface by atomization spraying. During the deposition process, the wet film thickness is monitored in real time by a laser thickness sensor, and the travel speed and atomization amount of the spraying equipment are dynamically adjusted according to the preset thickness distribution model.

[0011] Step S5: The deposited coating layer is programmed to be cured, and micro-nano texture processing and hydrophilic modification are performed on the surface of the cured coating layer to complete the preparation of the coating layer.

[0012] Step S6: Using an integrated tribometer and fluorescence spectrometer, the friction coefficient and damage fluorescence response sensitivity of the finished coating layer are detected in a simulated body fluid environment to obtain the coating performance evaluation value. Based on the comparison result between the coating performance evaluation value and the preset performance evaluation value, the qualification of the coating preparation is determined.

[0013] Step S7: Under the condition that the film preparation is unqualified, the energy density of plasma immersion ion implantation in step S1 is increased based on the difference between the preset performance evaluation value and the film performance evaluation value.

[0014] Furthermore, the processing procedure in step S1 includes:

[0015] The cleaned and qualified tweezers substrate is placed in a vacuum chamber for argon plasma sputtering cleaning and activation;

[0016] Carbon and silicon source gases are introduced into an argon plasma environment, and high-voltage pulses are applied to co-implant carbon and silicon ions. At the same time, the gas ratio is dynamically adjusted by real-time spectral monitoring.

[0017] Finally, the pulse energy is gradually reduced to smoothly transition the processing mode from high-energy injection to shallow deposition, forming a reinforced transition layer with continuously varying composition.

[0018] Furthermore, in step S1, the preset parameters include a gradient layer thickness of 50 to 200 nanometers, and the atomic percentage of its outermost surface satisfies a C:Si ratio between 1.5:1 and 3:1.

[0019] Furthermore, in step S2, the comprehensive quality evaluation value is determined based on the viscosity of the solution and the dispersion of the nanoparticles.

[0020] Furthermore, in step S2, the process of determining the qualification of the composite coating solution includes:

[0021] Compare the overall quality evaluation value with the preset quality evaluation value;

[0022] The composite coating solution was deemed unqualified based on the comparison result that the comprehensive quality evaluation value was less than the preset quality evaluation value.

[0023] The parameters of the composite coating solution are adjusted based on the nanoparticle stability index after the solution has been left to stand for a preset time.

[0024] Furthermore, in step S3, the process of adjusting the parameters of the composite coating solution includes:

[0025] Based on the comparison results of nanoparticle stability index being less than the preset stability index, it was determined to increase ultrasonic power;

[0026] Based on the comparison results of nanoparticle stability indices being greater than or equal to preset stability indices, the solution temperature was determined to be lowered.

[0027] Furthermore, the adjustment range of the ultrasonic power is positively correlated with the difference in the stability index, which is the difference between the preset stability index and the nanoparticle stability index.

[0028] Furthermore, in step S6, based on the comparison result that the film performance evaluation value is less than the preset performance evaluation value, the film preparation is determined to be unqualified, and the energy density of plasma immersion ion implantation in step S1 is increased based on the difference between the preset performance evaluation value and the film performance evaluation value.

[0029] Furthermore, the performance evaluation value of the film layer is determined based on the friction coefficient and damage fluorescence response sensitivity of the coating layer.

[0030] Furthermore, in step S1, the adjustment range of the energy density of plasma immersion ion implantation is positively correlated with the film performance difference, which is the difference between the preset performance evaluation value and the film performance evaluation value.

[0031] Compared with existing technologies, the beneficial effects of the method for preparing the forceps coating for obstetric use in this invention are that it constructs a gradient-strengthened transition layer with continuously changing composition (such as C and Si) and structure on the substrate surface through plasma immersion ion implantation and deposition technology. This transition layer effectively eliminates the internal stress concentration points caused by abrupt changes in the physical and chemical properties of the interface in traditional physical or chemical coatings, achieving a smooth transition of mechanical properties from the substrate to the functional coating. This not only greatly enhances the interfacial bonding force from both physical and chemical bonding levels, but also significantly improves the anti-peeling and anti-fatigue performance of the coating under complex stress conditions such as repeated opening and closing of forceps and shear friction with tissue, thus effectively solving the problems of easy peeling and short lifespan of coatings in clinical applications.

[0032] Furthermore, this invention also ensures the uniform and stable distribution of nanofunctional particles in the coating by introducing a solution quality assessment and dynamic adjustment mechanism based on static stability, combined with a real-time monitoring intelligent spraying process. This allows the coating's key functions, such as lubricity and antibacterial properties, to function effectively and persistently, even in harsh bodily fluid environments.

[0033] Furthermore, this invention obtains a comprehensive quality evaluation value through online rheological and dynamic light scattering detection, enabling a quantitative pre-judgment of the solution's processability (viscosity) and functional potential (nanoparticle dispersion). Furthermore, it introduces an evaluation and dynamic adjustment mechanism based on static stability (such as temperature and ultrasonic power adjustment) to actively maintain the dispersion stability of nanoparticles from a kinetic and thermodynamic perspective, preventing agglomeration and sedimentation before spraying. This mechanism, combined with an intelligent spraying process that monitors and dynamically adjusts thickness in real time, ensures the uniformity and consistency of hydroxylated boron nitride and other nanofunctional materials deposited on complex curved substrates, laying a solid microstructural foundation for the coating to achieve durable and uniform key functions such as lubrication and antibacterial properties.

[0034] Furthermore, this invention combines fluorescent detection with damage warning capabilities with tribological testing to quantitatively evaluate the performance of the finished product and establishes a precise traceability and adjustment mechanism for key upstream processes when performance fails to meet standards. This system achieves full-chain controllability and feedback optimization from raw materials and manufacturing processes to final performance, ensuring the consistency and reliability of product quality. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating a method for preparing a forceps covering layer for obstetric use according to an embodiment of the present invention;

[0036] Figure 2 This is a flowchart illustrating the process of determining the qualification of a composite coating solution based on a comprehensive quality evaluation value, as described in an embodiment of the present invention.

[0037] Figure 3This is a flowchart illustrating the adjustment of parameters of the composite coating solution based on the nanoparticle stability index after the solution has been left to stand for a preset time, according to an embodiment of the present invention.

[0038] Figure 4 This is a flowchart illustrating how the qualification of membrane preparation is determined based on membrane performance evaluation values, according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0040] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0041] It should be noted that the data in this embodiment are all derived from a comprehensive analysis and evaluation of historical test data and corresponding historical test results from the three months prior to this test. Those skilled in the art will understand that the determination of the above-mentioned parameters for any single item in this invention can be achieved by selecting the value with the highest percentage based on the data distribution as the preset standard parameter, using weighted summation to obtain the value as the preset standard parameter, substituting each historical data point into a specific formula and using the value obtained from that formula as the preset standard parameter, or other selection methods, as long as the invention can clearly define different specific situations in the single-item judgment process through the obtained values.

[0042] Please see Figure 1 As shown, it is a flowchart of the method for preparing the forceps covering layer for obstetrics according to an embodiment of the present invention;

[0043] The present invention provides a method for preparing a forceps covering layer for obstetric use, comprising:

[0044] Step S1: Plasma immersion ion implantation and deposition treatment is performed on the surface of the midwifery forceps substrate after precision cleaning and activation to form a gradient reinforcement transition layer with preset parameters on the surface of the midwifery forceps substrate.

[0045] Step S2: Prepare the composite coating solution, and use a rheometer and a dynamic light scattering instrument to detect the viscosity and nanoparticle dispersion of the solution online to obtain the comprehensive quality evaluation value of the solution, and determine the qualification of the composite coating solution based on the comprehensive quality evaluation value.

[0046] Step S3: Under the condition that the composite coating solution is unqualified, adjust the parameters of the composite coating solution based on the comparison results of the nanoparticle stability index after the solution has been left to stand for a preset time and the preset stability index, including increasing the ultrasonic power or decreasing the solution temperature.

[0047] Step S4: Deposit the qualified composite coating solution onto the substrate surface by atomization spraying. During the deposition process, the wet film thickness is monitored in real time by a laser thickness sensor, and the travel speed and atomization amount of the spraying equipment are dynamically adjusted according to the preset thickness distribution model.

[0048] Step S5: The deposited coating layer is programmed to be cured, and micro-nano texture processing and hydrophilic modification are performed on the surface of the cured coating layer to complete the preparation of the coating layer.

[0049] Step S6: Using an integrated tribometer and fluorescence spectrometer, the friction coefficient and damage fluorescence response sensitivity of the finished coating layer are tested in a simulated body fluid environment to obtain the coating performance evaluation value. Based on the comparison between the coating performance evaluation value and the preset performance evaluation value, the qualification of the coating preparation is determined.

[0050] Step S7: Under the condition that the film preparation is unqualified, the energy density of plasma immersion ion implantation in step S1 is increased based on the difference between the preset performance evaluation value and the film performance evaluation value.

[0051] Specifically, the processing steps in step S1 include:

[0052] The cleaned and qualified tweezers substrate is placed in a vacuum chamber for argon plasma sputtering cleaning and activation;

[0053] Carbon and silicon source gases are introduced into an argon plasma environment, and high-voltage pulses are applied to co-implant carbon and silicon ions. At the same time, the gas ratio is dynamically adjusted by real-time spectral monitoring.

[0054] Finally, the pulse energy is gradually reduced to smoothly transition the processing mode from high-energy injection to shallow deposition, forming a reinforced transition layer with continuously varying composition.

[0055] Specifically, in step S1, the preset parameters include a gradient layer thickness of 50 to 200 nanometers and an atomic percentage on the outermost surface of the gradient layer satisfying a C:Si ratio between 1.5:1 and 3:1, including cases equal to 1.5:1 or equal to 3:1.

[0056] Specifically, in step S2, the process of preparing the composite coating solution includes:

[0057] The medical-grade waterborne polyurethane resin (40% solid content) was filtered at a constant temperature (25℃) and placed into the main preparation vessel.

[0058] A primary slurry was prepared by high-shear dispersion (10,000 rpm, 20 minutes) of hydroxylated boron nitride nanosheets and a water-ethanol mixture containing a dispersant.

[0059] The primary slurry was subjected to probe-type ultrasonic treatment (500W, 10 seconds on / 5 seconds off) for a total of 20 minutes, with the temperature controlled in an ice bath below 25°C, to obtain a uniformly dispersed nano slurry.

[0060] The nano slurry was slowly added to the resin base under stirring (500 rpm), followed by the addition of leveling agent (0.2 wt%) and wetting agent (0.1 wt%), and stirring was continued for 30 minutes.

[0061] The above-mentioned uniformly mixed material was transferred to an ultrasonic dispersion tank and processed at a constant temperature of 25±2℃ with an ultrasonic power of 400W and a frequency of 20kHz. The intermittent ultrasonic mode was used (run for 5 seconds, pause for 2 seconds), and the total processing time was 8 to 12 minutes.

[0062] Adjust the pH of the mixture to 8.0±0.2 with ammonia, then let it stand for 60 minutes with low-speed stirring to allow the system to stabilize.

[0063] Before use, slowly add the water-soluble polyisocyanate crosslinking agent (the amount is calculated based on the NCO / OH molar ratio of 1.05:1) under low-speed stirring (200 rpm), and immediately switch to the online detection stage after stirring for 10 minutes.

[0064] Specifically, online detection includes using a rheometer to detect the flow of a solution at 25°C for 100 seconds. -1 Solution viscosity at shear rate, and nanoparticle dispersion detected using a dynamic light scattering instrument.

[0065] Please see Figure 2 As shown, it is a flowchart of the present invention for determining the qualification of the composite coating solution based on the comprehensive quality evaluation value;

[0066] Specifically, in step S2, the process of determining the qualification of the composite coating solution includes:

[0067] Compare the overall quality evaluation value with the preset quality evaluation value;

[0068] The composite coating solution was deemed unqualified based on the comparison result that the comprehensive quality evaluation value was less than the preset quality evaluation value.

[0069] The parameters of the composite coating solution are adjusted based on the nanoparticle stability index after the solution has been left to stand for a preset time.

[0070] Specifically, in step S2, the comprehensive quality evaluation value is determined based on the viscosity score and the dispersion score. The comprehensive quality evaluation value = first weighting coefficient w1 × viscosity score + second weighting coefficient w2 × dispersion score, where w1 + w2 = 1. Wherein, viscosity score = exp(-(μ - μ0)). 2 / 2σ 2 The formula is: μ = k × μ0, where μ is the solution viscosity, μ0 is the viscosity threshold, and σ is the standard deviation, where k = k × μ0, and k is the allowable viscosity range. The dispersibility score is calculated as 1 - PDI / PDImax, where PDI is the nanoparticle dispersibility and PDImax is the dispersibility threshold. For example, w1 = 0.5, w2 = 0.5, μ0 = 150 mPa·s, PDImax = 0.2, and k = 0.2. Both the viscosity score and the dispersibility score range from [0, 1], with higher values ​​indicating better quality.

[0071] In this embodiment of the invention, the preset quality evaluation value is determined based on the statistical correlation of historical production data. Specifically, under stable process parameters, historical batch data is collected, batches whose finished film performance meets the standards are selected, and the comprehensive quality evaluation values ​​of the solutions corresponding to these batches are extracted to form a qualified sample set. The lower limit or a specific quantile (such as the 5th percentile) of this sample set is calculated, and the resulting statistical value is established as the preset quality evaluation value; for example, the preset quality evaluation value is 0.65.

[0072] Understandably, solution viscosity is a key physical parameter affecting the feasibility of atomized spraying processes and the uniformity of film formation. The complex surface shape of the delivery forceps necessitates that the coating solution possess excellent rheological properties. Excessively high viscosity leads to difficulties in atomization, resulting in excessively large droplet sizes that easily cause flow, accumulation, or uneven coverage on the substrate surface, making it difficult to form a continuous, smooth, and controllable thickness wet film. Conversely, excessively low viscosity may cause "stringing" or splattering during spraying, similarly affecting uniformity, and may also negatively impact the mechanical properties of the film due to insufficient solids content.

[0073] Therefore, incorporating viscosity into the quality evaluation system and setting a reasonable threshold is the primary prerequisite for ensuring the stable implementation of subsequent spraying processes from a macroscopic rheological perspective. Nanoparticle dispersion is a core microscopic indicator for ensuring the functional uniformity and reliability of the coating layer. This invention constructs a comprehensive quality evaluation value using both viscosity and dispersion parameters to determine the solution's qualification, based on a profound consideration of the fundamental requirements for coating film quality and functional realization. Solution viscosity directly determines the feasibility of the spraying process and the macroscopic uniformity of the wet film, while nanoparticle dispersion fundamentally affects the compactness of the coating's microstructure, the uniformity of its mechanical properties, and the reliability of its core functions. The weighted combination of these two parameters can comprehensively and quantitatively reflect whether the solution simultaneously possesses good processability and functional potential.

[0074] Please see Figure 3 As shown, it is a flowchart of adjusting the parameters of the composite coating solution based on the nanoparticle stability index after the solution has been left to stand for a preset time, according to an embodiment of the present invention.

[0075] Specifically, in step S3, the process of adjusting the parameters of the composite coating solution includes:

[0076] Based on the comparison results of the nanoparticle stability index being less than the preset stability index, it is indicated that agglomerates already exist or are very likely to form in the solution. Therefore, it is determined to increase the ultrasonic power to enhance the cavitation effect, break up agglomerates, and improve the dispersion efficiency.

[0077] Based on the comparison results of the nanoparticle stability index being greater than or equal to the preset stability index, it is determined that the current dispersion state is good. Therefore, it is decided to reduce the solution temperature to reduce the Brownian motion kinetic energy of the particles and maintain the viscosity and density difference.

[0078] Specifically, the nanoparticle stability index is the ratio of the concentration of nanoparticles in the supernatant after the solution has been left to stand for a preset time to the initial concentration. Its value ranges from [0, 1]. The closer the value is to 1, the more stable the dispersion system is and the lower the tendency of nanoparticles to settle or aggregate.

[0079] In this embodiment of the invention, the preset duration is determined based on a balance between historical observation data on the dispersion stability of the composite coating solution and the process time requirements. Specifically, with fixed solution formulation and storage conditions, long-term stability monitoring is conducted on multiple batches of prepared qualified solutions, recording the change curve of nanoparticle dispersion over time. By analyzing this curve and considering actual production cycle requirements, the maximum time interval where the dispersion does not significantly deteriorate (e.g., PDI increases by no more than 10% of the initial value) and meets the production flow plan is selected as the preset duration; for example, the preset duration is 24 hours. The preset stability index is determined based on historical data statistics of the standing behavior of qualified solution samples. Specifically, multiple batches of solution samples that can still successfully pass through subsequent spraying processes and ultimately produce qualified finished products after standing for a preset duration are collected, and their nanoparticle stability index after standing is measured, forming a qualified sample dataset. The lower limit of this dataset (e.g., the 5th percentile or the mean minus two standard deviations) is calculated, and the resulting value is established as the preset stability index; for example, the preset stability index is 0.92.

[0080] Specifically, increasing the ultrasonic power directly enhances the external mechanical energy input required to overcome aggregation and restore stability. The essence of ultrasonic dispersion is to generate extremely strong local shear forces and shock waves through cavitation, thereby disrupting the van der Waals attraction between nanoparticles and achieving deagglomeration. Higher power results in greater cavitation intensity and a wider effective range, providing stronger dispersion energy. Therefore, the adjustment range of ultrasonic power is positively correlated with the difference in the stability index.

[0081] If the stability index difference is less than the preset stability difference, it indicates that the system stability is slightly insufficient, which may be just a slight soft agglomeration or the early stage of instability. Therefore, the ultrasonic power is adjusted to the corresponding value using the first power adjustment coefficient of 1.2.

[0082] If the stability index difference is greater than or equal to the preset stability difference, it indicates that the dispersion state has deteriorated significantly, with obvious aggregation or sedimentation. The conventional dispersion force can no longer maintain stability. Therefore, the ultrasonic power is adjusted to the corresponding value using the second power adjustment coefficient of 1.5.

[0083] The stability index difference is the difference between the preset stability index and the nanoparticle stability index.

[0084] In this embodiment of the invention, the initial value of the ultrasonic power is set to 400 W, and the adjusted ultrasonic power is the product of the initial ultrasonic power and the first power adjustment coefficient or the second power adjustment coefficient. The preset stability difference value is 0.05, but this value is not limited to this and can be adjusted according to the characteristics of the nanomaterial and the process requirements.

[0085] Specifically, the initial solution temperature is set to 25℃, with an adjustment range of 18℃~25℃. After detecting and determining that cooling is required, the system automatically starts the circulation cooling program of the storage tank jacket, steadily reducing the solution from the current temperature to the target temperature range at a rate of 1~2℃ / minute. The temperature sensor provides real-time feedback, and once the set value is reached, the system switches to heat preservation mode to maintain temperature fluctuations within ±0.5℃.

[0086] Understandably, when the nanoparticle stability index is lower than the preset value, it indicates that the solution exhibits a significant tendency for nanoparticle sedimentation or aggregation during the settling process. The root cause lies in insufficient dispersion kinetic stability, meaning that the repulsive forces between nanoparticles fail to effectively counteract van der Waals attraction, leading to aggregation. Increasing the ultrasonic power at this point enhances cavitation, microjets, and shear forces, directly disrupting the formed soft aggregates by inputting energy from the outside and raising the surface barrier of the particles. This fundamentally improves the dispersion state, allowing the stability index to return to the target level.

[0087] When the nanoparticle stability index reaches or exceeds the preset value, it indicates good dispersion. However, the system still triggers regulation, usually because the solution temperature is detected to be too high, or because process experience predicts that temperature may become a risk factor for subsequent stability. Excessive temperature accelerates solvent evaporation, induces resin prepolymerization, and enhances Brownian motion. While these thermodynamic processes may not immediately manifest as a decrease in dispersion, they subtly alter the thermodynamic equilibrium of the solution system, potentially leading to viscosity changes, secondary particle agglomeration, or performance drift. Lowering the solution temperature at this point controls the system within the optimal thermodynamic window, suppressing potential thermal disturbances and thus maintaining the solution's long-term stability from its initial testing to its actual use.

[0088] Specifically, in step S4, a qualified composite coating solution is uniformly deposited onto the substrate surface using a high-precision, low-pressure spraying device. During the spraying process, the device scans the substrate surface according to a pre-programmed three-dimensional path, while a laser thickness sensor monitors the wet film thickness in real time using a non-contact method. The thickness data is transmitted to the control system in real time and compared with a preset thickness distribution model. This model pre-sets differentiated target thickness ranges based on the wear resistance and lubrication requirements of different areas of the coating (such as contact surfaces, edges, and curved transition areas). Based on the deviation between the real-time thickness and the model's target value, the system dynamically adjusts the travel speed and atomization amount of the spraying device through closed-loop control: when the measured thickness is lower than the target value, the travel speed is appropriately reduced or the atomization amount is increased to increase the deposition in that area; when the measured thickness is close to or exceeds the upper limit, the travel speed is increased or the atomization amount is reduced to prevent local accumulation. This process ensures uniform coverage and precise shaping of the wet film on complex curved surfaces, providing an ideal initial state for subsequent curing.

[0089] Specifically, in step S5, the wet film after spray deposition undergoes a programmed curing process. The substrate is placed in a programmed temperature-controlled environment and undergoes a precise thermal process of gradient heating, holding, and slow cooling: first, a low heating rate is used to allow the solvent to fully evaporate and prevent bubble formation; then, a stepped holding process is performed within a specific temperature range to promote complete resin crosslinking reaction and form a dense and robust cured film. After curing, the film surface is micro- and nano-textured: a femtosecond laser is used to etch a composite textured pattern with micron-level grooves and nano-level protrusions in specific areas of the film (such as the main working surface in contact with tissue). This structure can effectively store lubricating media and reduce the contact area. Finally, the textured surface is treated with low-temperature oxygen plasma to introduce hydrophilic functional groups such as hydroxyl groups, significantly improving surface hydrophilicity, thereby forming a stable lubricating layer in the body fluid environment, ultimately obtaining a functionalized coating layer with high wear resistance, low coefficient of friction, and biocompatibility.

[0090] Please see Figure 4As shown, it is a flowchart of the process for determining the qualification of membrane preparation based on membrane performance evaluation values ​​in an embodiment of the present invention;

[0091] Specifically, in step S6, if the performance evaluation value of the coating layer is lower than the preset performance evaluation value, it indicates that the overall performance of the coating layer is defective and fails to meet the verified safe use standards. Therefore, the coating layer preparation is deemed unqualified, and the energy density of plasma immersion ion implantation in step S1 is increased based on the difference between the preset performance evaluation value and the coating layer performance evaluation value. Energy density is one of the most critical parameters determining the modification effect in the plasma immersion ion implantation process. The plasma immersion ion implantation process can form a gradient-strengthened transition layer with gradually changing composition on the surface of the metal substrate. Increasing the energy density can effectively enhance the interfacial adhesion between the coating and the substrate.

[0092] Based on the comparison results where the membrane performance evaluation value is greater than or equal to the preset performance evaluation value, the overall performance of the coating layer fully meets the standards and has the potential for safe and reliable clinical application. Therefore, the membrane preparation is deemed qualified.

[0093] Specifically, the performance evaluation value of the coating layer is determined based on the friction coefficient and the fluorescence response sensitivity of the coating layer. The performance evaluation value of the coating layer = friction coefficient weighting coefficient w3 × (friction coefficient threshold / measured friction coefficient) + fluorescence response weighting coefficient w4 × (measured fluorescence response sensitivity / fluorescence sensitivity threshold), and w3 + w4 = 1; where, for example, w3 = 0.6, w4 = 0.4, the friction coefficient threshold is set to 0.15, and the fluorescence sensitivity threshold is set to 200 RFU / μm².

[0094] In this embodiment of the invention, the determination of the preset performance evaluation value is based on a comprehensive correlation between clinical safety requirements, functional standards, and historical performance data. Specifically, several historical qualified product batches that have demonstrated safety, reliability, and functional compliance in a simulated application environment are collected and analyzed. The membrane performance evaluation values ​​obtained according to the testing method in step S6 are extracted to form a performance-compliant sample dataset. Through statistical analysis of this dataset, combined with the clinically permissible lower limit of performance fluctuation, the lower limit value or a specific quantile (such as the 10th percentile) of the sample is established as the preset performance evaluation value; for example, the preset performance evaluation value is 0.9.

[0095] Specifically, in step S6, the coated delivery forceps sample is placed in a simulated body fluid bath at 37°C, and subjected to reciprocating sliding friction using a tribometer with a preset load and frequency. The dynamic friction coefficient is recorded in real time, and the average value during the stable phase is taken. Simultaneously, in the friction trajectory region, the characteristic fluorescence signal intensity generated by the release of fluorescent indicators in the film layer due to frictional damage is collected and analyzed using a microprobe integrated with a fluorescence spectrometer after applying excitation light of a specific wavelength. The damage fluorescence response sensitivity value is obtained after normalization per unit area.

[0096] Specifically, when the film performance is deemed unqualified, it is determined that there is "insufficient coating-substrate interfacial bonding strength." When the interfacial bonding strength is insufficient, the kinetic energy of the implanted ions can be increased by increasing the energy density, thereby enhancing the interfacial bonding strength. Therefore, the adjustment range of the energy density of plasma immersion ion implantation in step S1 is positively correlated with the difference in film performance.

[0097] If the performance difference of the film layer is less than the preset performance difference, it indicates that the performance is close to the qualified line, which belongs to the boundary fluctuation or slight failure. Therefore, the energy density is adjusted to the corresponding value using the first energy adjustment coefficient of 1.25.

[0098] If the performance difference of the membrane layer is greater than or equal to the preset performance difference, it indicates that the performance is far below the standard, which is a clear and serious failure. Therefore, the energy density is adjusted to the corresponding value using a second energy adjustment coefficient of 1.5.

[0099] The membrane performance difference is the difference between the preset performance evaluation value and the membrane performance evaluation value.

[0100] In this embodiment of the invention, the initial reference value of energy density is set to 2.0 J / cm², and the preset performance difference value is 0.1. However, this value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0101] Understandably, the decline in film performance evaluation values ​​is mainly due to insufficient interfacial bonding strength between the substrate and the coating layer. Increasing the energy density of plasma immersion ion implantation can effectively enhance ion implantation depth and surface modification intensity, thereby improving the load-bearing capacity and interfacial bonding strength of the gradient strengthening transition layer. By establishing a hierarchical adjustment of the positive correlation between film performance difference and energy density, quantitative diagnosis and precise strengthening of interfacial problems are achieved, forming an intelligent control closed loop from performance feedback to adaptive optimization of process parameters.

[0102] It should be noted that steps S1 to S7 do not describe the production process of a single product, but rather the complete operating logic of an intelligent production system with "learning-optimization" capabilities that spans production batches. The adjustment target of step S7 is not the midwifery forceps base that has already been processed in this batch, but the "energy density" setting value in the process parameter database used to produce the next batch (or all subsequent batches) of products.

[0103] To better illustrate the method for preparing the forceps covering layer for use in obstetrics, the present invention will be further described below with reference to specific embodiments.

[0104] Example 1:

[0105] The specific preparation steps in this embodiment are the same as above, wherein:

[0106] The energy density is 2.0 J / cm²;

[0107] The ultrasonic power for preparing the composite coating solution was 400W;

[0108] The solution viscosity μ is 155 mPa·s, the nanoparticle dispersion PDI is 0.18, the allowable viscosity range k is 0.2, and the standard deviation σ is 30. The calculated comprehensive quality evaluation value is 0.543 (see the example description for the calculation process), which is less than the preset quality evaluation value (0.65). Therefore, this batch of composite coating solution is determined to be unqualified and needs to be adjusted according to step S3.

[0109] Example 2:

[0110] The specific preparation steps in this embodiment are the same as above, wherein:

[0111] The energy density is 2.0 J / cm²;

[0112] The ultrasonic power for preparing the composite coating solution is 600W;

[0113] The solution viscosity μ is 150 mPa·s, the nanoparticle dispersion PDI is 0.12, the allowable viscosity range k is 0.2, and the standard deviation σ is 30. The calculated comprehensive quality evaluation value is 0.7, which is greater than the preset quality evaluation value (0.65). Therefore, this batch of composite coating solution is deemed qualified and can proceed to the next spraying process.

[0114] The friction coefficient of the finished coating layer is 0.18, and the damage fluorescence response sensitivity is 185 RFU / μm². The calculated performance evaluation value of the coating layer is 0.87, which is less than the preset performance evaluation value (0.9). Therefore, the batch of coating layer preparation is deemed unqualified.

[0115] Example 3:

[0116] The specific preparation steps in this embodiment are the same as above, wherein:

[0117] The energy density is 2.5 J / cm²;

[0118] The ultrasonic power for preparing the composite coating solution was 600W;

[0119] The solution viscosity μ is 150 mPa·s, the nanoparticle dispersion PDI is 0.12, the allowable viscosity range k is 0.2, and the standard deviation σ is 30. The calculated comprehensive quality evaluation value is approximately 0.7, which is greater than the preset quality evaluation value (0.65). Therefore, this batch of composite coating solution is deemed qualified and can proceed to the next spraying process.

[0120] The coefficient of friction of the finished coating layer is 0.16, and the damage fluorescence response sensitivity is 190 RFU / μm². The calculated performance evaluation value of the coating layer is approximately 0.94, which is greater than the preset performance evaluation value (0.9). Therefore, the batch of coating layers is deemed to be qualified.

[0121] As can be seen from the above three examples, Example 1 reveals that under the initial parameters (ultrasonic power 400W), insufficient solution dispersion (PDI=0.14) led to an unqualified overall score (0.55). Example 2, by executing step S3, increased the ultrasonic power to 600W, successfully improving the dispersion state (PDI=0.16), making the overall solution score (0.57) meet the standard; however, the performance evaluation value of the finished film layer (0.834) was unqualified, indicating insufficient matrix reinforcement. Example 3 then, based on the feedback from step S7, increased the energy density of step S1 from 2.0 J / cm³. 2 Increased to 2.5 J / cm 2 Ultimately, the performance evaluation value of the finished film layer (0.94) met the standard. This series of results verifies the effectiveness of the dual closed-loop control logic of "online determination and adjustment of solution quality" and "feedback of finished product performance - process enhancement" in this scheme.

[0122] All technologies not mentioned in the above embodiments are applicable to existing technologies. It is understood that no specific limitation is made to any preset parameter or critical parameter in the embodiments of the present invention, and the above values ​​are not limited thereto. Those skilled in the art can adjust the preset parameters or critical parameters accordingly based on actual needs, analysis of historical data, or equipment usage.

[0123] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a diaphragm layer for obstetric forceps, characterized in that, include: Step S1: Plasma immersion ion implantation and deposition treatment is performed on the surface of the midwifery forceps substrate after precision cleaning and activation to form a gradient-strengthened transition layer with preset parameters. Step S2: Prepare a composite coating solution, and use a rheometer and a dynamic light scattering instrument to detect the viscosity and nanoparticle dispersion of the solution online to obtain a comprehensive quality evaluation value of the solution, and determine the qualification of the composite coating solution based on the comprehensive quality evaluation value. Step S3: Under the condition that the composite coating solution is unqualified, adjust the parameters of the composite coating solution based on the comparison result of the nanoparticle stability index after the solution has been left to stand for a preset time and the preset stability index. This includes increasing the ultrasonic power, or decreasing the solution temperature; Step S4: Deposit the qualified composite coating solution onto the substrate surface by atomization spraying. During the deposition process, the wet film thickness is monitored in real time by a laser thickness sensor, and the travel speed and atomization amount of the spraying equipment are dynamically adjusted according to the preset thickness distribution model. Step S5: The deposited coating layer is programmed to be cured, and micro-nano texture processing and hydrophilic modification are performed on the surface of the cured coating layer to complete the preparation of the coating layer. Step S6: Using an integrated tribometer and fluorescence spectrometer, the friction coefficient and damage fluorescence response sensitivity of the finished coating layer are detected in a simulated body fluid environment to obtain the coating performance evaluation value. Based on the comparison result between the coating performance evaluation value and the preset performance evaluation value, the qualification of the coating preparation is determined. Step S7: Under the condition that the film preparation is unqualified, the energy density of plasma immersion ion implantation in step S1 is increased based on the difference between the preset performance evaluation value and the film performance evaluation value.

2. The method for preparing the obstetric forceps covering layer according to claim 1, characterized in that, The processing procedure of step S1 includes: The cleaned and qualified tweezers substrate is placed in a vacuum chamber for argon plasma sputtering cleaning and activation; Carbon and silicon source gases are introduced into an argon plasma environment, and high-voltage pulses are applied to co-implant carbon and silicon ions. At the same time, the gas ratio is dynamically adjusted by real-time spectral monitoring. Finally, the pulse energy is gradually reduced to smoothly transition the processing mode from high-energy injection to shallow deposition, forming a reinforced transition layer with continuously varying composition.

3. The method for preparing the obstetric forceps covering layer according to claim 2, characterized in that, In step S1, the preset parameters include a gradient layer thickness of 50 to 200 nanometers and an atomic percentage of the outermost surface of the gradient layer satisfying a C:Si ratio of 1.5:1 to 3:

1.

4. The method for preparing a midwifery forceps covering layer for obstetric use according to claim 3, characterized in that, In step S2, the comprehensive quality evaluation value is determined based on the viscosity of the solution and the dispersion of nanoparticles.

5. The method for preparing a midwifery forceps covering layer for obstetric use according to claim 4, characterized in that, In step S2, the process of determining the qualification of the composite coating solution includes: Compare the overall quality evaluation value with the preset quality evaluation value; The composite coating solution was deemed unqualified based on the comparison result that the comprehensive quality evaluation value was less than the preset quality evaluation value. The parameters of the composite coating solution are adjusted based on the nanoparticle stability index after the solution has been left to stand for a preset time.

6. The method for preparing a midwifery forceps covering layer for obstetric use according to claim 5, characterized in that, In step S3, the process of adjusting the parameters of the composite coating solution includes: Based on the comparison results of nanoparticle stability index being less than the preset stability index, it was determined to increase ultrasonic power; Based on the comparison results of nanoparticle stability indices being greater than or equal to preset stability indices, the solution temperature was determined to be lowered.

7. The method for preparing a forceps covering layer for obstetric use according to claim 6, characterized in that, The adjustment range of the ultrasonic power is positively correlated with the difference in the stability index, which is the difference between the preset stability index and the nanoparticle stability index.

8. The method for preparing a forceps covering layer for obstetric use according to claim 7, characterized in that, In step S6, based on the comparison result that the film performance evaluation value is less than the preset performance evaluation value, the film preparation is determined to be unqualified, and the energy density of plasma immersion ion implantation in step S1 is increased based on the difference between the preset performance evaluation value and the film performance evaluation value.

9. The method for preparing a forceps covering layer for obstetric use according to claim 8, characterized in that, The performance evaluation values ​​of the coating layer are determined based on the friction coefficient and damage fluorescence response sensitivity of the coating layer.

10. The method for preparing a midwifery forceps covering layer for obstetric use according to claim 9, characterized in that, In step S1, the adjustment range of the energy density of plasma immersion ion implantation is positively correlated with the film performance difference, which is the difference between the preset performance evaluation value and the film performance evaluation value.

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