Detection method and system for antibacterial coating micro guide wire

Abstract

The invention discloses a method and a system for detecting an antibacterial coating micro guide wire. The method comprises the following steps: applying a composite stress field to a guide wire to obtain stress distribution data; determining a stress response abnormal area according to the stress distribution data and applying dual-frequency vibration excitation to obtain nonlinear vibration response data and vibration energy dissipation data; force-sensitive fluorescent molecules are applied to the stress response abnormal area for treatment, and conformational changes of the stress response abnormal area are monitored to obtain preliminary spatial distribution data of the microcracks; injecting a multi-ion fluorescent tracer into the micro-crack area, and monitoring the migration rule of the multi-ion fluorescent tracer to obtain pH value distribution data and oxidation-reduction potential distribution data; bacterial suspension with specific fluorescence response is injected into the micro-crack area, and antibacterial activity evaluation data is obtained by monitoring the fluorescence response of the bacterial suspension. According to the technical scheme, the microcracks on the surface of the antibacterial coating micro guide wire are accurately detected and positioned, and the influence degree of the microcracks on the antibacterial function can be accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of detection of antibacterial coating microguidewires, and particularly to a detection method and system for antibacterial coating microguidewires. Background Art

[0002] Antibacterial coating microguidewires are special medical devices used in cardiovascular and neurointerventional surgeries. Their basic structure includes a metal core (usually stainless steel, nitinol, or platinum-based alloy) and a surface antibacterial coating. This coating aims to inhibit the potential risk of microbial infection during the surgery and improve surgical safety. Common antibacterial coating materials include silver ion coatings, quaternary ammonium salt polymers, drug-releasing polymers (such as polyurethanes containing rifampicin or gentamicin), chlorhexidine coatings, and nanostructured surface modification coatings, etc. These coatings inhibit bacterial attachment and biofilm formation through different mechanisms, reducing related infection complications in interventional surgeries, especially for guidewire products that may need to be indwelled for a long time.

[0003] In clinical applications, microguidewires need to be frequently bent to adapt to complex vascular or nerve anatomical structures. This characteristic leads to specific mechanical challenges on the surface of the guidewire. During repeated bending of the microguidewire, stress concentration points will form in the bending area, causing the coating material to repeatedly experience tensile and compressive stress cycles. Under the action of this cyclic stress, although the coating surface remains intact macroscopically, a network of microcracks will gradually form at the microscopic level. The width of these microcracks is usually at the nanometer level, which is difficult to detect by the naked eye or conventional optical detection, but can provide an ideal colonization microenvironment for bacteria. More complicatedly, the local antibacterial drug concentration in these microcrack areas decreases, and the microenvironment formed inside the microcracks may weaken the effectiveness of the antibacterial agent and even promote the selective growth of certain drug-resistant strains. Therefore, developing a method that can accurately detect the microcracks on the surface of antibacterial coating microguidewires and evaluate their impact on the antibacterial function is of great significance for ensuring the safety of interventional surgeries and improving the quality of guidewire products. Summary of the Invention

[0004] The main purpose of the present invention is to accurately evaluate the actual impact of microcracks on the coating antibacterial function of microguidewires.

[0005] In the first aspect of the present invention, a detection method for antibacterial coating microguidewires is provided. The detection method for antibacterial coating microguidewires includes: Applying a composite stress field including spiral bending stress, periodic compressive stress waves, and temperature gradient stress to the guidewire to obtain stress distribution data on the surface of the guidewire; Determine the stress response abnormal region of the guide wire according to the stress distribution data, apply a dual-frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region, and obtain the non-linear vibration response data and vibration energy dissipation data of the stress response abnormal region; Apply a force-sensitive fluorescent molecule treatment to the stress response abnormal region, monitor the conformational changes of the force-sensitive fluorescent molecule according to the non-linear vibration response data and the vibration energy dissipation data, and obtain the preliminary spatial distribution data of microcracks on the surface of the guide wire; According to the preliminary spatial distribution data of microcracks, inject a multi-ion fluorescent tracer into the microcrack region indicated by the preliminary spatial distribution data of microcracks, and obtain the pH value distribution data and redox potential distribution data of the microcrack region by monitoring the migration law of the multi-ion fluorescent tracer; According to the pH value distribution data and the redox potential distribution data, inject a bacterial suspension with specific fluorescent response to the pH value and the redox potential into the microcrack region, and obtain the antibacterial activity evaluation data of the microcrack region by monitoring the fluorescent response of the bacterial suspension.

[0006] Preferably, applying a composite stress field including helical bending stress, periodic compressive stress wave and temperature gradient stress to the guide wire to obtain the stress distribution data on the surface of the guide wire includes: Apply a helical bending stress at a first preset angle to the guide wire and measure the initial stress distribution value on the surface of the guide wire; According to the initial stress distribution value, apply a periodic compressive stress wave with a first preset frequency at the stress measurement point where the stress value on the surface of the guide wire exceeds the first preset threshold, and measure the compressive stress response value at the stress measurement point; According to the compressive stress response value, adjust the frequency of the periodic compressive stress wave to 1.5 times the first preset frequency as the second preset frequency, and measure the compressive stress resonance value at the stress measurement point; According to the compressive stress resonance value, apply a temperature gradient stress at the stress measurement point and measure the thermal stress distribution value at the stress measurement point; Take the average value of the compressive stress response value and the compressive stress resonance value as the compressive stress comprehensive value, and perform weighted fusion calculation on the initial stress distribution value, the compressive stress comprehensive value and the thermal stress distribution value according to the thermal stress weight coefficient of 0.4, the compressive stress weight coefficient of 0.35 and the initial stress weight coefficient of 0.25 to obtain the stress distribution data on the surface of the guide wire.

[0007] Preferably, according to the compressive stress resonance value, applying a temperature gradient stress at the stress measurement point and measuring the thermal stress distribution value at the stress measurement point includes: Perform segmented processing on the compressive stress resonance value, and divide the stress measurement points into a high-response measurement sub-region and a low-response measurement sub-region; Apply a temperature gradient stress at a first preset temperature in the high-response measurement sub-region, and measure the first thermal expansion coefficient of the high-response measurement sub-region; According to the first thermal expansion coefficient, apply a temperature gradient stress at a second preset temperature in the low-response measurement sub-region, and measure the second thermal expansion coefficient of the low-response measurement sub-region; According to the difference between the first thermal expansion coefficient and the second thermal expansion coefficient, apply a temperature gradient stress at a third preset temperature to the high-response measurement sub-region and the low-response measurement sub-region, and measure the stress difference value of the stress measurement point; Perform linear combination calculations on the stress difference value with the first thermal expansion coefficient and the second thermal expansion coefficient respectively to obtain the thermal stress distribution value of the stress measurement point.

[0008] Preferably, the value range of the first preset frequency is 8 - 12 kHz; the value range of the first preset temperature is 35 - 40 °C; the value range of the second preset temperature is 45 - 50 °C; the value range of the third preset temperature is 55 - 60 °C; the heating rate of the temperature gradient stress is 2 °C / min, the cooling rate is 1 °C / min, and the temperature holding time is 5 min.

[0009] Preferably, determine the stress response abnormal region of the guide wire according to the stress distribution data, and apply a dual-frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region to obtain the non-linear vibration response data and vibration energy dissipation data of the stress response abnormal region, including: Perform threshold analysis on the stress distribution data, and take the region where the surface stress value of the guide wire is greater than the second preset threshold as the stress response abnormal region, where the second preset threshold is 1.5 times the average value of the stress distribution data; Apply vibration excitations with first frequencies of 15 kHz, 17.5 kHz, and 20 kHz to the stress response abnormal region in sequence to obtain a first frequency response data sequence; At each first frequency corresponding to the first frequency response data sequence, apply vibration excitations with second frequencies of 25 kHz, 27.5 kHz, and 30 kHz to the stress response abnormal region in sequence to obtain a dual-frequency combined response data sequence; According to the first frequency response data sequence and the dual-frequency combined response data sequence, calculate the amplitude ratio and phase delay angle for each frequency combination to obtain the non-linear vibration response data and the vibration energy dissipation data characterizing the microcrack response characteristics.

[0010] Preferably, for the treatment of applying a force-sensitive fluorescent molecule to the stress response abnormal region, the conformational change of the force-sensitive fluorescent molecule is monitored according to the non-linear vibration response data and the vibration energy dissipation data, and the preliminary spatial distribution data of the microcracks on the surface of the guide wire is obtained, including: According to the non-linear vibration response data, the section where the amplitude exceeds 2.5 times of the vibration reference value is used as the force-sensitive fluorescent molecule treatment area, where the vibration reference value is the average amplitude value of the crack-free area; A force-sensitive fluorescent molecule solution with a concentration of 0.08 mg / ml is applied to the force-sensitive fluorescent molecule treatment area, and the penetration time of the force-sensitive fluorescent molecule is regulated according to the energy concentration point determined by the vibration energy dissipation data, and the penetration time is positively correlated with the energy dissipation data; The force-sensitive fluorescent molecule is excited by light with a wavelength of 488 nm, and the first fluorescence intensity distribution of the force-sensitive fluorescent molecule in the state of not being loaded with stress is measured; A mechanical stress matching the non-linear vibration response data is applied to the force-sensitive fluorescent molecule, and the second fluorescence intensity distribution under the action of the stress is measured to obtain the preliminary spatial distribution data of the microcracks on the surface of the guide wire.

[0011] Preferably, according to the preliminary spatial distribution data of the microcracks, a multi-ion fluorescent tracer is injected into the microcrack region indicated by the preliminary spatial distribution data of the microcracks, and the pH value distribution data and the redox potential distribution data of the microcrack region are obtained by monitoring the migration law of the multi-ion fluorescent tracer, including: A first tracer solution composed of iron ions, copper ions and zinc ions in a molar ratio of 1:2:1 is injected into the microcrack region, and the first migration rates of the iron ions, copper ions and zinc ions are measured to obtain the depth distribution data of the microcrack region; According to the depth distribution data, a second tracer solution composed of a pH-sensitive fluorescent ion with a concentration of 0.1 mmol / L and a redox potential-sensitive fluorescent ion with a concentration of 0.2 mmol / L is injected into the microcrack region to obtain the initial fluorescence intensity distribution data of the microcrack region; An alternating electric field with a frequency of 50 Hz is applied to the second tracer solution, and the migration rate difference of the pH-sensitive fluorescent ion and the redox potential-sensitive fluorescent ion under the action of the electric field is measured to obtain the ion migration difference data of the microcrack region; According to the ion migration difference data, a gradient-modulated magnetic field is applied to the microcrack region, with the magnetic field intensity gradually increasing from 0.1 T to 0.5 T. The second migration rates of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions are measured to obtain the ion response data of the microcrack region; The depth distribution data, the initial fluorescence intensity distribution data, the ion migration difference data, and the ion response data are subjected to correlation analysis to obtain the pH value distribution data and the redox potential distribution data of the microcrack region.

[0012] Preferably, the step of applying a gradient-modulated magnetic field to the microcrack region according to the ion migration difference data, with the magnetic field intensity gradually increasing from 0.1 T to 0.5 T, measuring the second migration rates of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions, and obtaining the ion response data of the microcrack region includes: Performing spectral analysis on the ion migration difference data to obtain the maximum migration response frequencies of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions, and taking 0.8 - 1.2 times the maximum migration response frequency as the magnetic field modulation frequency; At the magnetic field modulation frequency, the magnetic field intensity is gradually increased from 0.1 T to 0.5 T at intervals of 0.1 T, and each intensity is maintained for 180 s. The migration distance differences of the two fluorescent ions in the X-axis, Y-axis, and Z-axis directions at each magnetic field intensity are measured to obtain the spatial connectivity data of the microcrack region; According to the spatial connectivity data, the maximum extension direction of the microcrack is determined, and the magnetic field direction is adjusted so that the angle between the magnetic field direction and the maximum extension direction is maintained within the range of 30° - 60°. The migration rate ratio of the two fluorescent ions in the magnetic field direction is measured to obtain the ion response data of the microcrack region.

[0013] Preferably, the step of injecting a bacterial suspension with specific fluorescence responses to the pH value and the redox potential into the microcrack region according to the pH value distribution data and the redox potential distribution data, and obtaining the antibacterial activity evaluation data of the microcrack region by monitoring the fluorescence response of the bacterial suspension includes: According to the pH value distribution data, a composite bacterial solution composed of a pH-responsive fluorescent reporter strain with a concentration of 1×10 6 CFU / ml and a redox potential-responsive fluorescent reporter strain with a concentration of 2×10 6 CFU / ml is injected into the microcrack region, and the initial fluorescence intensity distribution of the composite bacterial solution is measured at 37°C; Subject the microcrack region to alternating treatments of nutrient deprivation periods and nutrient enrichment periods, where the nutrient deprivation period lasts for 30 min and the nutrient enrichment period lasts for 15 min, and measure the change rate of fluorescence intensity of the two strains under stress conditions based on the initial fluorescence intensity to obtain bacterial stress response data; Apply an ion regulation solution composed of calcium ions at a concentration of 0.5 mmol / L and magnesium ions at a concentration of 0.3 mmol / L to the microcrack region, and measure the change of fluorescence signal of the two strains under ion regulation conditions to obtain bacterial metabolic activity data; Perform an oxygen concentration gradient treatment on the microcrack region, gradually reduce the oxygen concentration from 21% to 5%, and measure the fluorescence signal attenuation rate of the two strains under hypoxic conditions to obtain bacterial survival status data; Perform multi-parameter correlation analysis on the bacterial stress response data, the bacterial metabolic activity data, and the bacterial survival status data to obtain the antibacterial activity evaluation data of the microcrack region.

[0014] The second aspect of the present invention provides a detection system for an antibacterial coating micro-guidewire, and the detection system for the antibacterial coating micro-guidewire includes: A composite stress application module for applying a composite stress field including helical bending stress, periodic compressive stress waves, and temperature gradient stress to the guidewire to obtain stress distribution data on the surface of the guidewire; A dual-frequency vibration detection module for determining the stress response abnormal region of the guidewire according to the stress distribution data, and applying a dual-frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region to obtain non-linear vibration response data and vibration energy dissipation data of the stress response abnormal region; A force-sensitive fluorescence detection module for applying a force-sensitive fluorescent molecule treatment to the stress response abnormal region, and monitoring the conformational change of the force-sensitive fluorescent molecule according to the non-linear vibration response data and the vibration energy dissipation data to obtain preliminary spatial distribution data of microcracks on the surface of the guidewire; A multi-ion tracer detection module for injecting a multi-ion fluorescent tracer into the microcrack region indicated by the preliminary spatial distribution data of microcracks according to the preliminary spatial distribution data of microcracks, and obtaining pH value distribution data and redox potential distribution data of the microcrack region by monitoring the migration law of the multi-ion fluorescent tracer; An antibacterial activity evaluation module for injecting a bacterial suspension with specific fluorescence response to the pH value and the redox potential into the microcrack region according to the pH value distribution data and the redox potential distribution data, and obtaining the antibacterial activity evaluation data of the microcrack region by monitoring the fluorescence response of the bacterial suspension.

[0015] The technical solution provided by the embodiments of the present application applies a composite stress field through a guide wire, including spiral bending stress, periodic compressive stress waves, and temperature gradient stress, simulating the complex mechanical environment of the guide wire in clinical use. Since the material continuity in the microcrack region is destroyed, the stress distribution in this region is significantly different from that in the intact coating region. The torsional deformation generated by spiral bending can amplify this difference, the periodic compressive stress waves can induce the opening and closing of microcracks, and the temperature gradient further activates the microcracks through thermal stress, making their characteristics more obvious in the stress distribution data.

[0016] On this basis, a dual-frequency vibration excitation is applied to the region with abnormal stress response. Due to the existence of microcracks creating a discontinuous interface, when vibrations of two different frequencies meet here, a frequency modulation effect will occur. This modulation effect leads to the generation of new frequency components, manifested as a non-linear vibration response. At the same time, the interfacial friction and local deformation at the microcracks will cause additional energy losses, and these energy dissipation characteristics are directly related to the geometric shape and depth of the microcracks.

[0017] Force-sensitive fluorescent molecule detection utilizes the sensitivity of molecular structure to local stress. At the edges and tips of microcracks, there is a significant stress concentration phenomenon. After force-sensitive molecules enter these regions, the high-stress environment causes changes in the molecular conformation, exposing the fluorescent groups, thereby resulting in an enhanced local fluorescent signal. This stress-induced conformational change is spatially selective, enabling the contour of the microcracks to be accurately depicted.

[0018] The detection of multi-ion fluorescent tracers is based on the selective migration behavior of ions in the microcrack network. The microchannel system formed inside the microcracks has a unique surface charge distribution and chemical gradient. Different ions exhibit different migration rates and path selections in this environment due to differences in their charge, radius, and hydration characteristics. By analyzing these differences, the three-dimensional network structure and local chemical environment characteristics of the microcracks can be reconstructed.

[0019] In the final functional evaluation stage, the selected bacterial strain enables it to produce a measurable fluorescent response to changes in pH value and redox potential. When these bacteria enter the microcrack network, the local chemical environment changes will cause changes in the bacterial metabolic activities. This change is reflected through the change in the fluorescent signal, which can not only indicate the local effectiveness of antibacterial drugs but also reflect the impact of the microcrack environment on bacterial growth. Brief Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0021] Figure 1 It is a schematic diagram of an embodiment of the detection method of the antibacterial coating micro-guide wire in the embodiment of the present invention; Figure 2 It is a schematic diagram of an embodiment of the detection system of the antibacterial coating micro-guide wire in the embodiment of the present invention.

[0022] The realization of the object of the present invention, functional features and advantages will be further described in conjunction with the embodiments and with reference to the drawings. Detailed implementation manners

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0024] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0025] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, "and / or" throughout the text includes three scenarios. Taking A and / or B as an example, it includes the technical solution of A, the technical solution of B, and the technical solution that both A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, which must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] An embodiment of the present application provides a detection method for an antibacterial coating micro-guide wire. Figure 1A flowchart of a detection method for an antibacterial coating micro-guide wire provided by an embodiment of the present application. In this embodiment, the method includes: Please refer to Figure 1 , applying a composite stress field including a helical bending stress, a periodic compressive stress wave, and a temperature gradient stress to the guide wire to obtain stress distribution data on the surface of the guide wire; In an embodiment of the present invention, the applying a composite stress field including a helical bending stress, a periodic compressive stress wave, and a temperature gradient stress to the guide wire to obtain stress distribution data on the surface of the guide wire includes: Applying a helical bending stress at a first preset angle to the guide wire and measuring an initial stress distribution value on the surface of the guide wire; According to the initial stress distribution value, applying a periodic compressive stress wave at a first preset frequency to a stress measurement point where the stress value on the surface of the guide wire exceeds a first preset threshold, and measuring a compressive stress response value at the stress measurement point; According to the compressive stress response value, adjusting the frequency of the periodic compressive stress wave to 1.5 times the first preset frequency as a second preset frequency, and measuring a compressive stress resonance value at the stress measurement point; According to the compressive stress resonance value, applying a temperature gradient stress to the stress measurement point and measuring a thermal stress distribution value at the stress measurement point; Taking the average value of the compressive stress response value and the compressive stress resonance value as a compressive stress comprehensive value, and performing weighted fusion calculation on the initial stress distribution value, the compressive stress comprehensive value, and the thermal stress distribution value according to a thermal stress weight coefficient of 0.4, a compressive stress weight coefficient of 0.35, and an initial stress weight coefficient of 0.25 to obtain the stress distribution data on the surface of the guide wire.

[0027] Specifically, fix the guide wire on a clamping device and apply a helical bending stress at a first preset angle through a precision angle controller. Helical bending means that the guide wire undergoes torsional deformation around its axis direction, which is similar to the stress state when the guide wire passes through a curved blood vessel during clinical use. Use an optical strain gauge to collect the strain distribution image on the surface of the guide wire, and calculate the initial stress distribution value through the strain-stress conversion relationship. The stress distribution value on the surface of the guide wire reflects the stress condition of the coating during the deformation process. The larger this value is, the greater the stress borne by the local area and the higher the possibility of microcracks occurring. Here, helical bending is selected instead of simple bending because helical deformation can generate both torsional and bending stresses at the same time, which is closer to the actual use scenario.

[0028] Determine the first preset threshold through data analysis, and this threshold is set to 1.5 times the average stress value of the crack-free area. The positions exceeding this threshold are marked as stress measurement points, and these points are more likely to have microcracks. Apply a periodic compressive stress wave with the first preset frequency (8 - 12 kHz) to these measurement points, and the compressive stress wave is generated by a piezoelectric ceramic transducer. Use a laser Doppler vibrometer to measure the displacement response of the stress measurement points under the action of the compressive stress wave, and obtain the compressive stress response value through the displacement-stress conversion relationship. The frequency range of 8 - 12 kHz is selected based on the mechanical properties of the antibacterial coating material, and this frequency range can effectively excite the elastic response of the coating without causing additional damage.

[0029] Adjust the frequency of the periodic compressive stress wave to 1.5 times the first preset frequency (i.e., 12 - 18 kHz), and measure the compressive stress resonance value of the stress measurement points. The resonance value refers to the resonance response intensity of the material under specific frequency excitation. The frequency is increased to 1.5 times to observe the dynamic response characteristics of the coating at higher frequencies, because the microcrack area will exhibit more obvious nonlinear characteristics under high-frequency excitation. Use the same laser Doppler vibrometer to record the vibration response at this frequency and convert it into the compressive stress resonance value.

[0030] For the suspicious areas determined according to the compressive stress resonance value, apply a temperature gradient stress to these areas using a thermocouple array. The temperature gradient stress refers to the internal stress generated due to the non-uniform temperature distribution. Record the temperature distribution through an infrared thermal imager and calculate the thermal stress distribution value according to the thermal-stress relationship. This step combines the thermo-mechanical coupling effect and can further stimulate and amplify the characteristic response of microcracks.

[0031] Perform weighted fusion on the various types of stress data obtained. The average value of the compressive stress response value and the compressive stress resonance value is used as the comprehensive compressive stress value, which can balance the stress response characteristics at different frequencies. The setting of the weight coefficients (thermal stress 0.4, compressive stress 0.35, initial stress 0.25) considers the contribution degrees of different types of stress to microcrack detection: the weight of thermal stress is the highest because the temperature gradient can better reflect the depth information of microcracks; the compressive stress is the second, reflecting the importance of the dynamic response; the weight of the initial stress is the lowest, serving as a basic reference value. Through this weighted fusion, the obtained stress distribution data comprehensively reflects the stress state on the coating surface and the potential positions of microcracks.

[0032] In an embodiment of the present invention, according to the compressive stress resonance value, applying a temperature gradient stress to the stress measurement points and measuring the thermal stress distribution value of the stress measurement points includes: Perform segmented processing on the compressive stress resonance value, and divide the stress measurement points into high-response measurement sub-regions and low-response measurement sub-regions; Apply a temperature gradient stress of the first preset temperature to the high-response measurement sub-region, and measure the first thermal expansion coefficient of the high-response measurement sub-region; According to the first thermal expansion coefficient, apply a temperature gradient stress of the second preset temperature to the low-response measurement sub-region, and measure the second thermal expansion coefficient of the low-response measurement sub-region; According to the difference between the first thermal expansion coefficient and the second thermal expansion coefficient, apply a temperature gradient stress of the third preset temperature to the high-response measurement sub-region and the low-response measurement sub-region, and measure the stress difference value at the stress measurement point; Perform a linear combination calculation on the stress difference value with the first thermal expansion coefficient and the second thermal expansion coefficient respectively to obtain the thermal stress distribution value at the stress measurement point.

[0033] Specifically, sort the compressive stress resonance values according to their numerical magnitudes, select the regions where the resonance values are greater than twice the average value and label them as high-response measurement sub-regions, and label the remaining regions as low-response measurement sub-regions. The larger the resonance value, the more intense the response of the region under dynamic excitation. Taking the micro-guide wire with a quaternary ammonium salt polymer coating as an example, when micro-cracks exist, the resonance value of the high-response measurement sub-region is usually 2-3 times that of the low-response measurement sub-region. This zoning method is based on the physical property that the micro-crack region will exhibit a stronger vibration response under dynamic excitation due to structural discontinuity.

[0034] Use a precision temperature controller to apply a temperature gradient stress of the first preset temperature of 35-40 °C to the high-response measurement sub-region. The temperature gradient stress refers to the internal stress generated in the material under the action of a non-uniform temperature field, and the temperature distribution is monitored in real time by an infrared thermal imager. During the heating process, use a laser diameter gauge to measure the dimensional changes in this region, and calculate the first thermal expansion coefficient in combination with the temperature change amount. The quaternary ammonium salt polymer coating exhibits linear thermal expansion characteristics within this temperature range and does not undergo chemical property changes. The selection of 35-40 °C is based on the glass transition temperature of the coating material. Within this temperature range, the material can exhibit obvious thermal responses without damaging the coating structure.

[0035] According to the numerical range of the first thermal expansion coefficient, select 45-50 °C as the second preset temperature to apply a temperature gradient stress to the low-response measurement sub-region. The second preset temperature is 10 °C higher than the first preset temperature, and this temperature difference can highlight the thermal response differences in different regions. Use the same measurement equipment to obtain the second thermal expansion coefficient of the low-response measurement sub-region. Due to structural damage in the micro-crack region, its thermal expansion behavior will deviate from the normal value, and this deviation degree is related to the depth and distribution density of the micro-cracks.

[0036] Select 55 - 60 °C as the third preset temperature, which is below the critical point of the thermal stability of the coating material. Apply a temperature gradient stress to both the high-response measurement sub-region and the low-response measurement sub-region simultaneously, and use a strain gauge array to measure the stress difference value between the two regions. The stress difference between the two regions reflects the degree of influence of microcracks on the mechanical properties of the material. The third preset temperature is 10 °C higher than the second preset temperature. This step-by-step temperature increase method can fully expose the mechanical response characteristics of the material at different temperatures.

[0037] Perform a linear combination calculation on the stress difference value and the two thermal expansion coefficients. The specific calculation formula is: Thermal stress distribution value = k1 × Stress difference value + k2 × (First thermal expansion coefficient - Second thermal expansion coefficient), where k1 and k2 are weighting coefficients, k1 = 0.6, and k2 = 0.4. The weight of k1 is larger because the stress difference value directly reflects the change in the mechanical properties of the material, and the weight of k2 is smaller, which reflects the auxiliary judgment role of the thermal expansion characteristics. This calculation method comprehensively considers the response characteristics of the material in two dimensions of mechanics and thermotics, enabling the thermal stress distribution value to more accurately characterize the existence of microcracks.

[0038] In an embodiment of the present invention, the value range of the first preset frequency is 8 - 12 kHz; the value range of the first preset temperature is 35 - 40 °C; the value range of the second preset temperature is 45 - 50 °C; the value range of the third preset temperature is 55 - 60 °C; the heating rate of the temperature gradient stress is 2 °C / min, the cooling rate is 1 °C / min, and the temperature holding time is 5 min.

[0039] Specifically, the selection of the first preset frequency of 8 - 12 kHz is based on the mechanical properties of the antibacterial coating material. Taking the commonly used quaternary ammonium salt polymer coating as an example, its local shear modulus is in the range of 1 - 2 GPa, and the density is about 1.2 g / cm 3 , and the natural frequency of the material is about 10 kHz. Selecting a frequency range of 8 - 12 kHz can not only avoid the resonance frequency of the material to prevent excessive deformation but also ensure sufficient energy input to stimulate the dynamic response of microcracks.

[0040] The setting of the temperature parameters is closely related to the thermodynamic properties of the coating material. The first preset temperature of 35 - 40 °C is selected based on the glass transition temperature (Tg) of the coating material. This temperature range is located about 25 - 30 °C below the glass transition temperature (about 65 °C) of the coating material. In this temperature range, the material remains in the glassy state, showing stable linear elastic behavior, and the thermal expansion coefficient changes little, which is suitable as the reference measurement temperature.

[0041] The selection of the second preset temperature of 45 - 50 °C is a 10 °C increase based on the first preset temperature. This temperature difference can produce an obvious thermal stress effect. Within this temperature range, the material is still in a glassy state, but the thermal motion intensifies, and the molecular chain segment mobility increases, making the thermal expansion difference between the microcrack region and the intact region more obvious. At this temperature range, the thermal expansion coefficient of the quaternary ammonium salt polymer is about 6×10 -5 / K, which is sufficient to produce measurable dimensional changes.

[0042] The third preset temperature of 55 - 60 °C is close to but does not reach the glass transition temperature of the material. Within this temperature range, the thermal expansion coefficient of the material reaches its maximum value (about 8×10 -5 / K), and the stress concentration effect in the microcrack region is the most significant. At the same time, this temperature still does not cause irreversible transformation or degradation of the material, ensuring the repeatability of the measurement.

[0043] The setting of the heating rate of 2 °C / min and the cooling rate of 1 °C / min takes two factors into account: one is to ensure the uniformity of the temperature field. Too fast heating will lead to too large a temperature gradient; the other is to consider the thermal response characteristics of the material. The thermal diffusivity of the quaternary ammonium salt polymer is about 0.15 mm² / s. This heating and cooling rate can ensure that the material fully reaches thermal equilibrium. The cooling rate is less than the heating rate to reduce the sudden change of thermal stress and avoid generating additional microcracks.

[0044] The setting of the temperature holding time of 5 min is based on heat conduction calculation. Calculated with a coating thickness of 10 μm, the heat diffusion time is about 0.7 s. The 5 - minute holding time is sufficient to make the temperature field reach a steady - state distribution, and at the same time, it will not cause creep of the material due to too long a time. This time parameter ensures the accuracy and repeatability of the measurement data.

[0045] Please continue to refer to Figure 1 , determine the stress response abnormal region of the guide wire according to the stress distribution data, apply a dual - frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region, and obtain the non - linear vibration response data and vibration energy dissipation data of the stress response abnormal region; In an embodiment of the present invention, the determining the stress response abnormal region of the guide wire according to the stress distribution data, applying a dual - frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region, and obtaining the non - linear vibration response data and vibration energy dissipation data of the stress response abnormal region includes: Perform threshold analysis on the stress distribution data, and regard the area where the stress value on the guide wire surface is greater than the second preset threshold as the stress response abnormal area, where the second preset threshold is 1.5 times the average value of the stress distribution data; Apply first-frequency vibration excitations of 15 kHz, 17.5 kHz, and 20 kHz to the stress response abnormal area in sequence to obtain a first-frequency response data sequence; At each first frequency corresponding to the first-frequency response data sequence, apply second-frequency vibration excitations of 25 kHz, 27.5 kHz, and 30 kHz to the stress response abnormal area in sequence to obtain a dual-frequency combined response data sequence; According to the first-frequency response data sequence and the dual-frequency combined response data sequence, calculate the amplitude ratio and phase delay angle under each frequency combination to obtain the nonlinear vibration response data and the vibration energy dissipation data characterizing the microcrack response characteristics.

[0046] Specifically, use image processing software to perform threshold analysis on the stress distribution data. First, calculate the average stress of the entire guide wire surface, and multiply this average value by 1.5 as the second preset threshold. Taking the quaternary ammonium salt polymer coating as an example, the stress value in the normal area is distributed in the range of 2 - 3 MPa. When the local stress value exceeds 1.5 times the average value (i.e., 3 - 4.5 MPa), it indicates that there is a stress concentration phenomenon in this area. Selecting 1.5 times as the threshold multiple is based on the yield strength of the coating material. At this stress level, the material begins to show microscopic structural changes but has not yet undergone macroscopic damage. Mark the area exceeding this threshold as the stress response abnormal area, and these areas often have a high correlation with the location of microcracks.

[0047] Use a piezoelectric actuator to apply first-frequency vibration excitations of 15 kHz, 17.5 kHz, and 20 kHz to the stress response abnormal area in sequence. The selection of the vibration frequency is based on the mechanical properties of the coating material: 15 kHz is close to the elastic wave propagation frequency of the material and can effectively excite the basic vibration mode of the material; 17.5 kHz and 20 kHz correspond to the second-order and third-order vibration modes of the material respectively. Use a laser Doppler vibrometer to measure the vibration displacement at each frequency, record the amplitude and phase information, and form a first-frequency response data sequence. The interval between these three frequency points is set to 2.5 kHz, which can not only ensure sufficient frequency resolution but also cover the main vibration characteristics of the material.

[0048] On the basis of each first frequency, second frequency vibration excitations of 25 kHz, 27.5 kHz, and 30 kHz are superimposed. The second frequency is selected to be 10 kHz higher than the first frequency, and this frequency difference can produce an obvious beat frequency effect. The beat frequency effect refers to the phenomenon of periodic intensity variation generated by the superposition of vibrations of two close frequencies. The same laser Doppler vibrometer is used to record the vibration response under the dual-frequency excitation, and a dual-frequency combined response data sequence containing nine groups of frequency combinations is obtained. The measurement time for each group of frequency combinations is 1 s, which can include a complete vibration cycle.

[0049] Perform Fourier transform on the response data of each group of frequency combinations to extract the fundamental frequency and harmonic components. Calculate the amplitude ratio (i.e., the ratio of the harmonic amplitude to the fundamental frequency amplitude) and the phase delay angle (i.e., the difference between the harmonic phase and the fundamental frequency phase) under different frequency combinations. The amplitude ratio reflects the degree of nonlinear response of the material, and the phase delay angle reflects the energy dissipation characteristics. Due to the structural discontinuity in the microcrack region, a larger amplitude ratio (>0.3) and phase delay angle (>45°) will be exhibited. These data together constitute the nonlinear vibration response data and vibration energy dissipation data characterizing the microcrack response characteristics. Through this dual-frequency excitation method, the dynamic response characteristics of microcracks can be captured more comprehensively, improving the detection accuracy.

[0050] Please continue to refer to Figure 1 , apply a force-sensitive fluorescent molecule treatment to the stress response abnormal region, monitor the conformational change of the force-sensitive fluorescent molecule according to the nonlinear vibration response data and the vibration energy dissipation data, and obtain the preliminary spatial distribution data of microcracks on the surface of the guide wire; In an embodiment of the present invention, the applying a force-sensitive fluorescent molecule treatment to the stress response abnormal region, monitoring the conformational change of the force-sensitive fluorescent molecule according to the nonlinear vibration response data and the vibration energy dissipation data, and obtaining the preliminary spatial distribution data of microcracks on the surface of the guide wire includes: According to the nonlinear vibration response data, the section where the amplitude exceeds 2.5 times the vibration reference value is used as the force-sensitive fluorescent molecule treatment region, where the vibration reference value is the average amplitude value of the crack-free region; Apply a force-sensitive fluorescent molecule solution with a concentration of 0.08 mg / ml to the force-sensitive fluorescent molecule treatment region, and regulate the penetration time of the force-sensitive fluorescent molecule according to the energy concentration point determined by the vibration energy dissipation data. The penetration time is positively correlated with the energy dissipation data; Optically excite the force-sensitive fluorescent molecule with a wavelength of 488 nm, and measure the first fluorescence intensity distribution of the force-sensitive fluorescent molecule in the unstressed state; Apply mechanical stress matching the non-linear vibration response data to the force-sensitive fluorescent molecules, measure the second fluorescence intensity distribution under the action of the stress, and obtain the preliminary spatial distribution data of the microcracks on the surface of the guide wire.

[0051] Specifically, measure the vibration response of the intact area (i.e., crack-free area) on the surface of the guide wire through a laser Doppler vibrometer, and calculate the average amplitude value as the vibration reference value. Select the section where the amplitude exceeds 2.5 times this reference value as the area to be treated with the force-sensitive fluorescent molecules. The threshold of 2.5 times is based on the mechanical properties of the microcrack area: taking the quaternary ammonium salt polymer coating as an example, when microcracks appear, the local stiffness decreases, resulting in a significant increase in amplitude. Experimental verification shows that the amplitude value in the microcrack area is generally 2.5 - 3 times that of the intact area. This screening method based on the amplitude ratio can accurately locate the microcrack area.

[0052] Prepare a force-sensitive fluorescent molecule solution with a concentration of 0.08 mg / ml. The force-sensitive fluorescent molecule is a special molecule that undergoes conformational changes and produces fluorescence when subjected to mechanical stress, such as poly(N-isopropylacrylamide). The concentration of 0.08 mg / ml is selected based on two considerations: one is to ensure sufficient fluorescence signal intensity, and the other is to avoid the influence of intermolecular interactions on the detection sensitivity. Use a micro syringe to apply the solution to the treatment area, and the penetration time is determined according to the energy dissipation data. The larger the dissipation value, the more developed the microcrack network, and the longer the penetration time is required. The specific calculation formula is: penetration time (min) = 5 + 10×(energy dissipation value / reference dissipation value).

[0053] Use an argon ion laser to generate excitation light with a wavelength of 488 nm to irradiate the force-sensitive fluorescent molecules. The wavelength of 488 nm is selected because it coincides with the excitation peak of the force-sensitive fluorescent molecules and can produce the strongest fluorescence signal. Use a confocal microscope to collect the fluorescence image and record the first fluorescence intensity distribution in the state without applied stress. The first fluorescence intensity distribution reflects the initial distribution state of the force-sensitive molecules in the microcrack network and serves as a reference baseline for subsequent stress responses.

[0054] Use a piezoelectric ceramic actuator to apply mechanical stress to the force-sensitive fluorescent molecules. The magnitude of the applied stress matches the non-linear vibration response data, that is, a larger stress is applied in the area with a stronger vibration response. Use the same confocal microscope system to collect the second fluorescence intensity distribution under the action of the stress. By calculating the ratio of the second fluorescence intensity to the first fluorescence intensity, draw a fluorescence intensity change map to obtain the spatial distribution data of the microcracks. In the microcrack area, due to local stress concentration, the conformation of the force-sensitive molecules changes significantly, manifested as a fluorescence intensity ratio greater than 2. This detection method based on force-sensitive fluorescence combines mechanical response and optical characterization, providing an intuitive image of the microcrack distribution.

[0055] Please continue to refer to Figure 1 , and according to the preliminary spatial distribution data of the microcracks, inject a multi-ion fluorescent tracer into the microcrack region indicated by the preliminary spatial distribution data of the microcracks, and obtain the pH value distribution data and redox potential distribution data of the microcrack region by monitoring the migration law of the multi-ion fluorescent tracer; In an embodiment of the present invention, the injecting a multi-ion fluorescent tracer into the microcrack region indicated by the preliminary spatial distribution data of the microcracks according to the preliminary spatial distribution data of the microcracks, and obtaining the pH value distribution data and redox potential distribution data of the microcrack region by monitoring the migration law of the multi-ion fluorescent tracer includes: Inject a first tracer solution composed of iron ions, copper ions and zinc ions in a molar ratio of 1:2:1 into the microcrack region, measure the first migration rates of the iron ions, copper ions and zinc ions, and obtain the depth distribution data of the microcrack region; According to the depth distribution data, inject a second tracer solution composed of pH-sensitive fluorescent ions with a concentration of 0.1 mmol / L and redox potential-sensitive fluorescent ions with a concentration of 0.2 mmol / L into the microcrack region, and obtain the initial fluorescence intensity distribution data of the microcrack region; Apply an alternating electric field of 50 Hz to the second tracer solution, measure the migration rate difference between the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions under the action of the electric field, and obtain the ion migration difference data of the microcrack region; According to the ion migration difference data, apply a gradient-modulated magnetic field to the microcrack region, the magnetic field intensity gradually increases from 0.1 T to 0.5 T, measure the second migration rates of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions, and obtain the ion response data of the microcrack region; Perform correlation analysis on the depth distribution data, the initial fluorescence intensity distribution data, the ion migration difference data and the ion response data to obtain the pH value distribution data and redox potential distribution data of the microcrack region.

[0056] Specifically, a first tracer solution composed of iron ions, copper ions, and zinc ions in a molar ratio of 1:2:1 is prepared. The selection of these three ions is based on their different physicochemical properties: the radius of iron ions is 0.645 Å, copper ions are 0.73 Å, and zinc ions are 0.74 Å. This particle size difference causes them to exhibit different migration behaviors in the microcrack network. The 1:2:1 molar ratio is designed because copper ions have the strongest complexation ability and can form stable coordination with the functional groups on the microcrack surface, while iron ions and zinc ions mainly reflect the geometric characteristics of the microcracks. Using fluorescently labeled metal ion chelates, the migration processes of these three ions are tracked through a confocal microscope, and their diffusion rates in the microcrack network are recorded. The differences in the migration rates of iron ions, copper ions, and zinc ions directly reflect the depth distribution of the microcracks because the greater the depth, the more obvious the spatial limitation on ion migration.

[0057] Based on the depth distribution data, the main distribution regions of the microcracks are determined, and a second tracer solution composed of pH-sensitive fluorescent ions and redox potential-sensitive fluorescent ions is injected into these regions. The pH-sensitive fluorescent ion selected is: BCECF (2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein), with a concentration of 0.1 mmol / L; The redox potential-sensitive fluorescent ion selected is a rhodamine derivative, with a concentration of 0.2 mmol / L. The selection of these two concentrations is based on the balance between fluorescence signal intensity and background interference: BCECF is most sensitive to pH changes (in the pH range of 6 - 8) at 0.1 mmol / L, and the rhodamine derivative has the best response to redox potential changes (in the range of -200 mV to +200 mV) at 0.2 mmol / L. A dual-channel fluorescence microscope is used to simultaneously record the distributions of the two fluorescent ions, obtaining the initial fluorescence intensity distribution data.

[0058] An alternating electric field of 50 Hz is applied using parallel electrode plates. The selection of the 50 Hz frequency is based on the migration characteristics of ions in aqueous solutions: at this frequency, the response time of ions (about 20 ms) matches their characteristic diffusion time in the microcracks, enabling effective differentiation of the migration behaviors of different ions. Under the action of the electric field, the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions exhibit different migration rates due to differences in charge and mass. Time-resolved fluorescence imaging technology is used to record the migration trajectories of the two ions, and the rate differences in the direction of the electric field are calculated. This difference reflects the electric field distribution and chemical environment inhomogeneity inside the microcracks.

[0059] Based on the ion migration difference data, determine the areas that need to be focused on, and apply a gradient-modulated magnetic field. Use an electromagnet to generate the magnetic field, with the intensity increasing by one gradient every 0.1 T starting from 0.1 T until 0.5 T. The selection of the magnetic field intensity range takes two factors into account: 0.1 T is the threshold at which fluorescent ions begin to exhibit an obvious magnetic response, and 0.5 T is the upper limit that does not affect the structure of the coating material. Measure the migration rates of the two fluorescent ions at each magnetic field intensity. The magnetic field action will change the diffusion path of the ions, and the degree of this change is closely related to the spatial orientation and local chemical environment of the microcracks.

[0060] Process various data obtained through multi-parameter correlation analysis. Use the partial least squares regression method to establish the mapping relationship between the data: the depth distribution data reflects the geometric characteristics of the microcracks, the initial fluorescence distribution reflects the initial state of the chemical environment, the ion migration difference data characterizes the local electric field effect, and the ion response data reflects the environmental changes under external field regulation. Through the comprehensive analysis of these data, calculate the pH value distribution (accurate to 0.1 pH unit) and the redox potential distribution (accurate to 10 mV) in the microcrack region. This multi-dimensional characterization method provides a detailed chemical environment map of the microcrack region, providing an important basis for evaluating the antibacterial function.

[0061] In one embodiment of the present invention, according to the ion migration difference data, apply a gradient-modulated magnetic field to the microcrack region, with the magnetic field intensity gradually increasing from 0.1 T to 0.5 T, measure the second migration rates of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions, and obtain the ion response data of the microcrack region, including: Conduct a spectral analysis on the ion migration difference data to obtain the maximum migration response frequencies of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions, and use 0.8 - 1.2 times the maximum migration response frequency as the magnetic field modulation frequency; At the magnetic field modulation frequency, increase the magnetic field intensity from 0.1 T step by step at intervals of 0.1 T to 0.5 T, and maintain each intensity for 180 s. Measure the differences in the migration distances of the two fluorescent ions in the X-axis, Y-axis, and Z-axis directions at each magnetic field intensity to obtain the spatial connectivity data of the microcrack region; Determine the maximum extension direction of the microcracks based on the spatial connectivity data, adjust the magnetic field direction so that the angle between the magnetic field direction and the maximum extension direction remains within the range of 30° - 60°, and measure the migration rate ratio of the two fluorescent ions in the magnetic field direction to obtain the ion response data of the microcrack region.

[0062] Specifically, the ion migration difference data is subjected to fast Fourier transform to obtain the spectrum characteristics. pH-sensitive fluorescent ions (BCECF) and redox potential-sensitive fluorescent ions (rhodamine derivatives) exhibit periodic migration behavior under the action of an alternating electric field, and this migration behavior will have characteristic peaks in the frequency domain. The peak detection algorithm is used to identify the maximum response peak in the spectrum, and the peak frequency is the maximum migration response frequency. Taking BCECF as an example, its maximum migration response frequency is usually in the range of 45-55Hz. The range of 0.8-1.2 times the maximum migration response frequency is selected as the magnetic field modulation frequency. This range selection is based on the relaxation time of ions in microcracks: too high a frequency will cause the ions to not have time to respond, and too low a frequency will reduce the detection sensitivity. This frequency selection method based on the intrinsic response characteristics of the ions ensures the effectiveness of magnetic field modulation.

[0063] A three-dimensionally positioned electromagnetic coil system was used to generate a magnetic field at a determined magnetic field modulation frequency. The magnetic field strength started at 0.1T and increased by a gradient of 0.1T to 0.5T, and each strength was maintained for 180s. The setting of the maintenance time of 180s was based on the characteristic diffusion time of ions in the microcrack network: based on a microcrack depth of 10μm, it takes about 120s for the ions to diffuse completely, and an additional 60s is used to ensure that the system reaches a steady state. At each magnetic field strength, a three-dimensional confocal microscopy system was used to simultaneously track the movement of the two fluorescent ions in three directions: the X-axis (parallel to the axial direction of the guide wire), the Y-axis (perpendicular to the surface of the guide wire), and the Z-axis (along the circumference of the guide wire). The difference in the migration distance of the two ions in each direction was calculated, and these differences reflected the spatial connectivity of the microcrack network. A larger difference indicates that there is a through microcrack channel in that direction, while a smaller difference indicates that the channel is blocked or not connected.

[0064] The principal component analysis of the spatial connectivity data was performed to determine the main extension direction of the microcrack network. The maximum extension direction refers to the spatial direction with the largest difference in migration distance, which is usually related to the formation mechanism of microcracks. According to the maximum extension direction, the direction of the electromagnetic coil is adjusted to keep the angle between the magnetic field direction and the maximum extension direction within the range of 30°-60°. The selection of this angle range is due to the characteristics of the Lorentz force: when the angle between the movement direction of the charged particle and the magnetic field direction is within this range, the magnetic force is most conducive to revealing the spatial structure of the microcracks. The migration rates of the two fluorescent ions in the adjusted magnetic field direction are measured, and their ratio is calculated. This ratio eliminates the influence of the geometry of the microcracks and directly reflects the regulatory effect of the local chemical environment on the movement of ions. By analyzing the distribution of the migration rate ratio at different positions, the complete ion response data of the microcrack area is obtained, which accurately describes the chemical environment characteristics of the microcrack network.

[0065] Please continue reading Figure 1, according to the pH value distribution data and the redox potential distribution data, inject a bacterial suspension with specific fluorescence response to the pH value and the redox potential into the microcrack region, and obtain the antibacterial activity evaluation data of the microcrack region by monitoring the fluorescence response of the bacterial suspension.

[0066] In one embodiment of the present invention, the step of injecting a bacterial suspension with specific fluorescence response to the pH value and the redox potential into the microcrack region according to the pH value distribution data and the redox potential distribution data, and obtaining the antibacterial activity evaluation data of the microcrack region by monitoring the fluorescence response of the bacterial suspension includes: According to the pH value distribution data, inject a composite bacterial solution composed of a pH-responsive fluorescent reporter strain with a concentration of 1×10 6 CFU / ml and a redox potential-responsive fluorescent reporter strain with a concentration of 2×10 6 CFU / ml into the microcrack region, and measure the initial fluorescence intensity distribution of the composite bacterial solution at 37°C. Apply alternating nutrient deficiency periods and nutrient enrichment periods to the microcrack region, where the nutrient deficiency period lasts for 30 min and the nutrient enrichment period lasts for 15 min, and measure the fluorescence intensity change rates of the two strains under stress conditions based on the initial fluorescence intensity to obtain bacterial stress response data. Apply an ion regulation solution composed of calcium ions with a concentration of 0.5 mmol / L and magnesium ions with a concentration of 0.3 mmol / L to the microcrack region, and measure the fluorescence signal changes of the two strains under ion regulation conditions to obtain bacterial metabolic activity data. Perform an oxygen concentration gradient treatment on the microcrack region, gradually reduce the oxygen concentration from 21% to 5%, and measure the fluorescence signal attenuation rates of the two strains under anoxic conditions to obtain bacterial survival state data. Perform multi-parameter correlation analysis on the bacterial stress response data, the bacterial metabolic activity data, and the bacterial survival state data to obtain the antibacterial activity evaluation data of the microcrack region.

[0067] Specifically, select the injection points in the microcrack region according to the pH value distribution data, and inject the composite bacterial solution using a micro syringe. The concentration of the pH-responsive fluorescent reporter strain (Escherichia coli, carrying a pH-sensitive protein gene) is 1×10 6 CFU / ml, and the concentration of the redox potential-responsive fluorescent reporter strain (Staphylococcus aureus, carrying a redox potential-sensitive protein gene) is 2×10 6 CFU / ml. The determination of these two concentration values is based on a bacterial detection sensitivity experiment: 1×10 6CFU / ml is the lowest concentration at which the pH-responsive strain produces a detectable fluorescent signal, and 2×10 6 CFU / ml is the concentration at which the redox potential-responsive strain achieves the optimal signal-to-noise ratio. The wire infused with the composite bacterial solution was placed in an incubator at 37°C, and the initial fluorescent images of the two strains were collected using a fluorescence microscope. 37°C is the optimal growth temperature for bacteria, at which the metabolic activity of bacteria is the strongest and the fluorescent signal is the most stable.

[0068] The microcrack region was alternately treated with a nutrient-deprived period and a nutrient-enriched period. The nutrient-deprived period used a minimal medium without a carbon source for 30 min; the nutrient-enriched period used a complete medium rich in glucose and amino acids for 15 min. The setting of these two time parameters was based on the stress response kinetics of bacteria: 30 min of nutrient deprivation was sufficient to trigger the stress response of bacteria but would not cause irreversible damage, and 15 min of nutrient enrichment could fully activate the metabolic system of bacteria. A time-resolved fluorescence microscope was used to record the changes in the fluorescence intensity of the two strains at different times, and the change rate relative to the initial fluorescence intensity was calculated. This nutrient alternation treatment simulated the uneven nutrient distribution in the microcrack environment, and the stress response of bacteria reflected the impact of the local environment on their survival.

[0069] An ion regulation solution containing 0.5 mmol / L calcium ions and 0.3 mmol / L magnesium ions was prepared. The selection of these two ion concentrations was based on the physiological characteristics of bacteria: a calcium ion concentration of 0.5 mmol / L could significantly affect the signal transduction system of bacteria, and a magnesium ion concentration of 0.3 mmol / L was the optimal concentration required to maintain the integrity of the bacterial membrane. The ion regulation solution was injected into the microcrack region using a perfusion system, and the changes in the fluorescent signals of the two strains were monitored using a real-time fluorescence imaging system. The change in the ion environment would cause a change in the metabolic activity of bacteria, and this change was reflected by the change in the intensity of the fluorescent signal.

[0070] A gas mixing control system was used to perform an oxygen concentration gradient treatment on the microcrack region. The oxygen concentration was decreased by 4% every 30 min from the normal atmospheric level (21%) until it reached 5%. This concentration range was selected because the range from 21% to 5% covered the transition interval from aerobic to microaerophilic, which could fully reflect the response of bacteria to changes in oxygen concentration. A fluorescence lifetime imaging system was used to measure the fluorescence signal decay rate of the two strains at different oxygen concentrations, and this parameter directly reflected the survival state of bacteria.

[0071] The data obtained is processed using multivariate statistical analysis methods. Bacterial stress response data, metabolic activity data, and survival status data are input into the principal component analysis model to extract the main influencing factors. The correlation relationship between the data is established through partial least squares regression, and the antibacterial activity index of each microcrack region is calculated. This index comprehensively reflects the degree of influence of microcracks on bacterial growth, and the higher the value, the stronger the antibacterial activity. This multi-parameter analysis method avoids the limitations of a single index and provides a more comprehensive antibacterial activity evaluation result.

[0072] The detection method of the antibacterial coating microguide wire in the embodiment of the present invention is described above. Next, the detection system of the antibacterial coating microguide wire in the embodiment of the present invention will be described. Please refer to Figure 2 , an embodiment of the detection system of the antibacterial coating microguide wire in the embodiment of the present invention includes: A composite stress application module 101, configured to apply a composite stress field including helical bending stress, periodic compressive stress waves, and temperature gradient stress to the guide wire to obtain stress distribution data on the surface of the guide wire; A dual-frequency vibration detection module 102, configured to determine the stress response abnormal region of the guide wire according to the stress distribution data, and apply a dual-frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region to obtain non-linear vibration response data and vibration energy dissipation data of the stress response abnormal region; A force-sensitive fluorescence detection module 103, configured to apply a force-sensitive fluorescent molecule treatment to the stress response abnormal region, and monitor the conformational change of the force-sensitive fluorescent molecule according to the non-linear vibration response data and the vibration energy dissipation data to obtain preliminary spatial distribution data of microcracks on the surface of the guide wire; A multi-ion tracer detection module 104, configured to inject a multi-ion fluorescent tracer into the microcrack region indicated by the preliminary spatial distribution data of microcracks according to the preliminary spatial distribution data of microcracks, and obtain pH value distribution data and redox potential distribution data of the microcrack region by monitoring the migration law of the multi-ion fluorescent tracer; An antibacterial activity evaluation module 105, configured to inject a bacterial suspension with specific fluorescence response to the pH value and the redox potential into the microcrack region according to the pH value distribution data and the redox potential distribution data, and obtain antibacterial activity evaluation data of the microcrack region by monitoring the fluorescence response of the bacterial suspension.

[0073] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A detection method for an antibacterial coating micro-guide wire, characterized in that Including: Applying a composite stress field including helical bending stress, periodic compressive stress wave and temperature gradient stress to the guide wire to obtain stress distribution data on the surface of the guide wire; Determining the stress response abnormal area of the guide wire according to the stress distribution data, and applying a dual-frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal area to obtain the nonlinear vibration response data and vibration energy dissipation data of the stress response abnormal area; Applying a force-sensitive fluorescent molecule treatment to the stress response abnormal area, monitoring the conformational change of the force-sensitive fluorescent molecule according to the nonlinear vibration response data and the vibration energy dissipation data, and obtaining preliminary spatial distribution data of microcracks on the surface of the guide wire; According to the preliminary spatial distribution data of microcracks, injecting a multi-ion fluorescent tracer into the microcrack area indicated by the preliminary spatial distribution data of microcracks, and obtaining pH value distribution data and redox potential distribution data of the microcrack area by monitoring the migration law of the multi-ion fluorescent tracer; According to the pH value distribution data and the redox potential distribution data, injecting a bacterial suspension with specific fluorescence response to the pH value and the redox potential into the microcrack area, and obtaining antibacterial activity evaluation data of the microcrack area by monitoring the fluorescence response of the bacterial suspension.

2. The detection method of the antibacterial coating micro-guide wire according to claim 1, wherein, The applying a composite stress field including helical bending stress, periodic compressive stress wave and temperature gradient stress to the guide wire to obtain stress distribution data on the surface of the guide wire includes: Applying a helical bending stress at a first preset angle to the guide wire and measuring the initial stress distribution value on the surface of the guide wire; According to the initial stress distribution value, applying a periodic compressive stress wave at a first preset frequency to the stress measurement point where the stress value on the surface of the guide wire exceeds a first preset threshold, and measuring the compressive stress response value of the stress measurement point; According to the compressive stress response value, adjusting the frequency of the periodic compressive stress wave to 1.5 times the first preset frequency as the second preset frequency, and measuring the compressive stress resonance value of the stress measurement point; According to the compressive stress resonance value, applying a temperature gradient stress to the stress measurement point and measuring the thermal stress distribution value of the stress measurement point; Taking the average value of the compressive stress response value and the compressive stress resonance value as the compressive stress comprehensive value, and performing weighted fusion calculation on the initial stress distribution value, the compressive stress comprehensive value and the thermal stress distribution value according to a thermal stress weight coefficient of 0.4, a compressive stress weight coefficient of 0.35 and an initial stress weight coefficient of 0.25 to obtain the stress distribution data on the surface of the guide wire.

3. The detection method of the antibacterial coating micro-guide wire according to claim 2, characterized in that, The applying a temperature gradient stress to the stress measurement point according to the compressive stress resonance value and measuring the thermal stress distribution value of the stress measurement point includes: Performing segmented processing on the compressive stress resonance value and dividing the stress measurement point into a high-response measurement sub-region and a low-response measurement sub-region; Applying a temperature gradient stress at a first preset temperature to the high-response measurement sub-region and measuring the first thermal expansion coefficient of the high-response measurement sub-region; According to the first coefficient of thermal expansion, apply a temperature gradient stress at a second preset temperature in the low-response measurement sub-region, and measure the second coefficient of thermal expansion of the low-response measurement sub-region; According to the difference between the first coefficient of thermal expansion and the second coefficient of thermal expansion, apply a temperature gradient stress at a third preset temperature to the high-response measurement sub-region and the low-response measurement sub-region, and measure the stress difference value at the stress measurement point; Perform a linear combination calculation on the stress difference value with the first coefficient of thermal expansion and the second coefficient of thermal expansion respectively to obtain the thermal stress distribution value at the stress measurement point.

4. The detection method of the antibacterial coating micro-guide wire according to claim 3, characterized in that, The value range of the first preset frequency is 8 - 12 kHz; the value range of the first preset temperature is 35 - 40 °C; the value range of the second preset temperature is 45 - 50 °C; the value range of the third preset temperature is 55 - 60 °C; the heating rate of the temperature gradient stress is 2 °C / min, the cooling rate is 1 °C / min, and the temperature holding time is 5 min.

5. The detection method of the antibacterial coating micro-guide wire according to claim 1, characterized in that Determine the stress response abnormal region of the guide wire according to the stress distribution data, and apply a dual-frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region to obtain the non-linear vibration response data and vibration energy dissipation data of the stress response abnormal region, including: Perform a threshold analysis on the stress distribution data, and take the region where the surface stress value of the guide wire is greater than the second preset threshold as the stress response abnormal region, where the second preset threshold is 1.5 times the average value of the stress distribution data; Apply vibration excitations with first frequencies of 15 kHz, 17.5 kHz, and 20 kHz to the stress response abnormal region in sequence to obtain a first frequency response data sequence; At each first frequency corresponding to the first frequency response data sequence, apply vibration excitations with second frequencies of 25 kHz, 27.5 kHz, and 30 kHz to the stress response abnormal region in sequence to obtain a dual-frequency combined response data sequence; According to the first frequency response data sequence and the dual-frequency combined response data sequence, calculate the amplitude ratio and phase delay angle for each frequency combination to obtain the non-linear vibration response data and the vibration energy dissipation data characterizing the microcrack response characteristics.

6. The detection method of the antibacterial coating micro-guide wire according to claim 1, characterized in that, Apply a force-sensitive fluorescent molecule treatment to the stress response abnormal region, and monitor the conformational change of the force-sensitive fluorescent molecule according to the non-linear vibration response data and the vibration energy dissipation data to obtain the preliminary spatial distribution data of microcracks on the surface of the guide wire, including: According to the non-linear vibration response data, take the section where the amplitude exceeds 2.5 times the vibration reference value as the force-sensitive fluorescent molecule treatment region, where the vibration reference value is the average amplitude value of the crack-free region; Apply a force-sensitive fluorescent molecule solution with a concentration of 0.08 mg / ml to the force-sensitive fluorescent molecule treatment region, and regulate the penetration time of the force-sensitive fluorescent molecule according to the energy concentration point determined by the vibration energy dissipation data, and the penetration time is positively correlated with the energy dissipation data; The force-sensitive fluorescent molecules are excited by light with a wavelength of 488 nm, and the first fluorescence intensity distribution of the force-sensitive fluorescent molecules in the stress-free state is measured; A mechanical stress matching the non-linear vibration response data is applied to the force-sensitive fluorescent molecules, and the second fluorescence intensity distribution under the stress is measured to obtain the preliminary spatial distribution data of the microcracks on the surface of the guide wire.

7. The detection method of the antibacterial coating micro-guide wire according to claim 1, characterized in that According to the preliminary spatial distribution data of the microcracks, a multi-ion fluorescent tracer is injected into the microcrack regions indicated by the preliminary spatial distribution data of the microcracks, and the pH value distribution data and the redox potential distribution data of the microcrack regions are obtained by monitoring the migration rules of the multi-ion fluorescent tracer, including: A first tracer solution composed of iron ions, copper ions and zinc ions in a molar ratio of 1:2:1 is injected into the microcrack regions, and the first migration rates of the iron ions, copper ions and zinc ions are measured to obtain the depth distribution data of the microcrack regions; According to the depth distribution data, a second tracer solution composed of pH-sensitive fluorescent ions with a concentration of 0.1 mmol / L and redox potential-sensitive fluorescent ions with a concentration of 0.2 mmol / L is injected into the microcrack regions to obtain the initial fluorescence intensity distribution data of the microcrack regions; An alternating electric field of 50 Hz is applied to the second tracer solution, and the migration rate differences of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions under the action of the electric field are measured to obtain the ion migration difference data of the microcrack regions; According to the ion migration difference data, a gradient-modulated magnetic field is applied to the microcrack regions, and the magnetic field intensity is gradually increased from 0.1 T to 0.5 T, and the second migration rates of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions are measured to obtain the ion response data of the microcrack regions; The depth distribution data, the initial fluorescence intensity distribution data, the ion migration difference data and the ion response data are subjected to correlation analysis to obtain the pH value distribution data and the redox potential distribution data of the microcrack regions.

8. The detection method of the antibacterial coating micro-guide wire according to claim 7, characterized in that, According to the ion migration difference data, a gradient-modulated magnetic field is applied to the microcrack regions, and the magnetic field intensity is gradually increased from 0.1 T to 0.5 T, and the second migration rates of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions are measured to obtain the ion response data of the microcrack regions, including: The ion migration difference data is subjected to spectral analysis to obtain the maximum migration response frequencies of the pH-sensitive fluorescent ions and the redox potential-sensitive fluorescent ions, and 0.8 - 1.2 times the maximum migration response frequency is used as the magnetic field modulation frequency; At the magnetic field modulation frequency, the magnetic field intensity is gradually increased from 0.1 T to 0.5 T at intervals of 0.1 T, and each intensity is maintained for 180 s, and the migration distance differences of the two fluorescent ions in the X-axis, Y-axis and Z-axis directions at each magnetic field intensity are measured to obtain the spatial connectivity data of the microcrack regions; Determine the maximum extension direction of the microcracks according to the spatial connectivity data, adjust the magnetic field direction so that the angle between the magnetic field direction and the maximum extension direction is maintained within the range of 30° - 60°, measure the migration rate ratio of two fluorescent ions under the magnetic field direction, and obtain the ion response data of the microcrack region.

9. The detection method of the antibacterial coating micro-guide wire according to claim 1, characterized in that, According to the pH value distribution data and the redox potential distribution data, inject a bacterial suspension with specific fluorescence response to the pH value and the redox potential into the microcrack region, and obtain the antibacterial activity evaluation data of the microcrack region by monitoring the fluorescence response of the bacterial suspension, including: According to the pH value distribution data, inject a composite bacterial solution composed of a pH-responsive fluorescent reporter strain with a concentration of 1×10 6 CFU / ml and a redox potential-responsive fluorescent reporter strain with a concentration of 2×10 6 CFU / ml into the microcrack region, and measure the initial fluorescence intensity distribution of the composite bacterial solution at 37°C; Apply alternating treatments of nutrient deficiency period and nutrient enrichment period to the microcrack region, where the nutrient deficiency period lasts for 30 min and the nutrient enrichment period lasts for 15 min, measure the fluorescence intensity change rate of two strains under stress conditions based on the initial fluorescence intensity, and obtain the bacterial stress response data; Apply an ion regulation solution composed of calcium ions with a concentration of 0.5 mmol / L and magnesium ions with a concentration of 0.3 mmol / L to the microcrack region, measure the fluorescence signal change of two strains under ion regulation conditions, and obtain the bacterial metabolic activity data; Perform an oxygen concentration gradient treatment on the microcrack region, gradually reduce the oxygen concentration from 21% to 5%, measure the fluorescence signal attenuation rate of two strains under hypoxic conditions, and obtain the bacterial survival state data; Perform multi-parameter correlation analysis on the bacterial stress response data, the bacterial metabolic activity data, and the bacterial survival state data, and obtain the antibacterial activity evaluation data of the microcrack region.

10. A detection system for an antibacterial coated micro-guide wire, characterized in that, Including: A composite stress application module for applying a composite stress field including spiral bending stress, periodic compressive stress wave, and temperature gradient stress to the guide wire to obtain the stress distribution data on the surface of the guide wire; A dual-frequency vibration detection module for determining the stress response abnormal region of the guide wire according to the stress distribution data, and applying a dual-frequency vibration excitation composed of a first frequency of 15 - 20 kHz and a second frequency of 25 - 30 kHz to the stress response abnormal region to obtain the non-linear vibration response data and vibration energy dissipation data of the stress response abnormal region; A force-sensitive fluorescence detection module for applying a force-sensitive fluorescence molecule treatment to the stress response abnormal region, and monitoring the conformational change of the force-sensitive fluorescence molecule according to the non-linear vibration response data and the vibration energy dissipation data to obtain the preliminary spatial distribution data of microcracks on the surface of the guide wire; A multi-ion tracer detection module for injecting a multi-ion fluorescence tracer into the microcrack region indicated by the preliminary spatial distribution data of microcracks according to the preliminary spatial distribution data of microcracks, and obtaining the pH value distribution data and redox potential distribution data of the microcrack region by monitoring the migration law of the multi-ion fluorescence tracer; An antibacterial activity evaluation module, which is used to inject a bacterial suspension with specific fluorescence responses to the pH value and the redox potential into the microcrack region according to the pH value distribution data and the redox potential distribution data, and obtain antibacterial activity evaluation data of the microcrack region by monitoring the fluorescence response of the bacterial suspension.

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