Blood shearing device and blood compatibility evaluation method

Abstract

The invention relates to a blood shearing device and a blood compatibility evaluation method. The blood shearing device comprises an objective table, a fixing support, a supporting beam, a stator, a rotor and a driving source. The device can simultaneously adjust the roughness and wettability of the material surface, breaks through the limitation that only a single factor can be researched in the prior art, and provides a more comprehensive platform for systematically evaluating the blood compatibility; in the experimental method, red blood cell hemolysis is detected, and the degradation condition of plasma protein is evaluated synchronously, so that the overall injury mode of blood components under the action of an artificial surface can be reflected more truly. Experimental basis can be provided for material selection and surface optimization of blood contact type medical instruments such as an artificial heart pump, an ECMO and a hemodialysis machine, the clinical complication risk can be reduced, and development of artificial organs and blood purification technologies is promoted.

Description

Technical Field

[0001] This invention relates to the field of experimental apparatus technology, and in particular to a blood shearing device and a method for evaluating blood compatibility. Background Technology

[0002] In recent years, the incidence of heart failure and severe cardiopulmonary diseases has continued to rise globally, and patients' demand for life support and blood purification therapy has become increasingly urgent. This has driven the widespread use of blood-contact medical devices such as artificial heart pumps, extracorporeal membrane oxygenation (ECMO), and hemodialysis machines. These devices, through mechanical circulatory support or blood purification technology, effectively replace or assist damaged heart, lung, and kidney functions, significantly prolonging the survival time of critically ill patients and improving their quality of life. They have become indispensable key treatment equipment in the field of modern critical care medicine.

[0003] However, blood-contact medical devices face a core challenge in clinical application—insufficient blood compatibility. Due to the complex internal flow channel design of the device, blood is in a non-physiological flow environment during circulation, inevitably subjected to multiple factors such as high shear forces, turbulent impacts, and device surface roughness. These factors directly lead to damage to blood components, specifically red blood cell rupture (i.e., hemolysis) and degradation of key functional proteins in plasma (especially high molecular weight von Willebrand factor, VWF). Hemolysis can cause complications such as anemia and acute kidney injury, while VWF degradation can disrupt the body's normal hemostasis mechanism, leading to acquired hemophilia-like bleeding tendencies, which can even be life-threatening in severe cases. These blood damage issues not only reduce the therapeutic efficacy and long-term safety of medical devices but also become a significant bottleneck restricting the further promotion and application of advanced devices such as artificial heart pumps and ECMO.

[0004] Currently, the industry lacks an experimental platform capable of simultaneously controlling surface roughness and wettability and systematically evaluating their synergistic damage mechanisms to blood components (especially erythrocytes and VWF). This makes it impossible to provide comprehensive and reliable experimental evidence for the selection of medical device materials and surface optimization. Furthermore, experiments using existing platforms often focus on a single factor, only considering the impact of surface roughness on erythrocytes, neglecting the crucial variable of material wettability. However, the regulatory role of wettability in VWF degradation and protein adsorption has been proven to be essential for blood compatibility evaluation. Single-factor studies lead to biased evaluation results that fail to reflect the true interaction between materials and blood. Detection indicators are limited, assessing hemolysis only by measuring free hemoglobin concentration, without quantitative analysis of key plasma proteins such as VWF that affect coagulation and hemostasis, making it difficult to comprehensively reflect the impact of device surfaces on the human coagulation system. Experimental designs lack dynamism, with most studies only performing single sampling at the experimental endpoint, failing to capture the dynamic evolution of blood component damage over time and revealing the progressive mechanisms and key time points of blood damage.

[0005] In summary, there is a significant gap between the current needs for evaluating blood compatibility in the field of blood-contact medical devices and the capabilities of existing technologies. There is an urgent need to develop an experimental device and evaluation method that can achieve multi-factor regulation, multi-index detection, flexible structure, and dynamic monitoring capabilities to address the shortcomings of existing technologies and provide scientific and comprehensive experimental support for the optimization of medical device materials and clinical applications. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology by developing an experimental device and evaluation method that can realize multi-factor regulation, multi-index detection, flexible structure and dynamic monitoring capability.

[0007] To address the aforementioned technical problems, the present invention provides a blood shearing device, comprising, Stage; A fixed bracket is mounted on the platform. A support beam, which is connected to the fixed bracket; The stator is mounted on the support beam, and the side surface of the stator is machined with a predetermined roughness. The rotor is coaxially sleeved outside the stator, and there is a gap between the inner wall of the rotor and the side of the stator to form an annular space for accommodating blood. A drive source is connected to the platform, and the output shaft of the drive source is coaxially connected to the rotor.

[0008] In one embodiment of the present invention, the stage includes a base plate and support legs. Four support legs arranged in a positive direction are connected to one side of the base plate by fasteners, and each support leg is coaxially connected to a support foot at the end away from the base plate.

[0009] In one embodiment of the present invention, a central through hole is coaxially formed on the substrate, the fixing bracket is coaxially mounted on the side of the substrate away from the support leg, the fixing bracket is provided with a through hole coaxial with the central through hole, the driving source is connected to the side of the substrate away from the support leg, and the output shaft of the driving source coaxially passes through the central through hole and the through hole and is connected to the rotor.

[0010] In one embodiment of the present invention, the stator includes a first body and a first connecting shaft. The first body is cup-shaped, and the first connecting shaft is coaxially connected to the bottom surface inside the first body. A threaded connection hole is coaxially provided at the end of the first connecting shaft away from the first body.

[0011] In one embodiment of the present invention, the support beam is a U-shaped structure, with a connecting lug at each end of the support beam and the two connecting lugs extending in a direction away from each other. A first connecting hole is opened on each of the two connecting lugs and connected to a fixed bracket at the first connecting hole by a fastener. At the same time, a second connecting hole is opened at the middle position of the support beam, and a bolt is coaxially arranged in the second connecting hole. The first connecting shaft is screwed onto the bolt.

[0012] In one embodiment of the present invention, the rotor includes a second body and a second connecting shaft. The second body is cup-shaped and coaxially sleeved outside the first body. The second connecting shaft is coaxially connected to the bottom surface of the outer side of the second body. The second connecting shaft is connected to the output shaft of the drive source through a coupling.

[0013] In one embodiment of the invention, a controller is further included, the controller being connected to the drive source.

[0014] A method for evaluating blood compatibility, comprising processing the blood to be tested using a blood shearing device as described in any one of the above claims, characterized by the following steps: Step S1: Prepare a set of stators made of hydrophilic material, and make the sides of each stator have different predetermined roughness; Step S2: Prepare another set of stators made of hydrophobic material, and make the roughness of each stator side surface correspond to the roughness of each stator side surface prepared in step S1. Step S3: Conduct experiments using two sets of stators respectively. The experimental steps are as follows: Step S3-1: Inject a predetermined amount of blood to be tested, after anticoagulation treatment, into the annular space formed by the stator and rotor; Step S3-2: Start the drive source to drive the rotor to rotate at a predetermined speed, so that the blood to be tested circulates at a preset shear rate; Step S3-3: Collect blood samples at multiple predetermined time points; Step S3-4: Test the collected blood samples. The test indicators include the level of red blood cell hemolysis and the degree of degradation of von Willebrand factor (VWF). Step S4: Based on the detection results of steps S3-4, analyze the effects of different surface roughness and different wettability materials on erythrocyte hemolysis and VWF degradation.

[0015] In one embodiment of the present invention, in steps S3-4, the level of erythrocyte hemolysis is determined by plasma free hemoglobin concentration, and the degree of degradation of von Willebrand factor (VWF) is detected by immunoblotting to determine the retention rate of high molecular weight VWF.

[0016] In one embodiment of the present invention, in steps S1 and S2, the roughness of the circumferential surface of each stator is in the range of 0.2 μm to 1.2 μm.

[0017] The technical solution of the present invention has the following advantages compared with the prior art: This invention discloses a blood shearing device and a blood compatibility evaluation method. The device employs a modular design, allowing for flexible switching of material types and surface states, avoiding experimental result biases caused by fixed materials and limited roughening areas in traditional devices. Researchers can quickly replace the inner cylinder with different materials and surface treatments according to experimental needs, comparing the effects of different materials and surface treatments on blood compatibility under the same flow field conditions, significantly improving the comparability and repeatability of the experiments. It overcomes the limitation of existing technologies that can only study a single factor, enabling simultaneous adjustment of material surface roughness and wettability. This innovative design allows researchers to comprehensively and systematically explore the combined effects of these two key factors on blood compatibility, providing a richer perspective for a deeper understanding of the interaction mechanism between blood and material surfaces. By simultaneously changing surface roughness and wettability, the flow environment of blood in actual medical devices can be simulated more realistically, thereby more accurately assessing the blood compatibility of materials and providing a more comprehensive experimental basis for the screening and optimization of medical device materials. Furthermore, the experimental method not only detects erythrocyte hemolysis but also simultaneously assesses the degradation of plasma proteins (especially high molecular weight VWFs). This multi-index detection method can more realistically reflect the overall damage pattern of blood components under the action of artificial surfaces, avoiding the one-sidedness of relying on a single index to assess blood compatibility. Attached Figure Description

[0018] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein... Figure 1 This is an isometric view of a blood shearing device according to a preferred embodiment of the present invention; Figure 2 This is an exploded view of a blood shearing device according to a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the fixed bracket of the blood shearing device according to a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the support beam of the blood shearing device according to a preferred embodiment of the present invention; Figure 5 This is a schematic diagram of the stator structure of a preferred embodiment of the blood shearing device of the present invention; Figure 6 This is a schematic diagram of the rotor structure of the blood shearing device according to a preferred embodiment of the present invention; Figure 7 This is a schematic diagram of the stator and rotor of the blood shearing device according to a preferred embodiment of the present invention, with the stator and rotor installed together.

[0019] Explanation of reference numerals in the accompanying drawings: 1. Stage; 11. Base plate; 111. Central through hole; 12. Support leg; 2. Fixed bracket; 21. Fixed plate; 22. Connecting part; 23. Through hole; 3. Support beam; 31. First connecting hole; 32. Second connecting hole; 4. Stator; 41. First body; 42. First connecting shaft; 421. Threaded connecting hole; 5. Rotor; 51. Second body; 52. Second connecting shaft; 6. Drive source; 7. Coupling; 8. Blood to be tested. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0021] Example 1, refer to Figures 1-7 As shown, a blood shearing device of the present invention includes, Stage 1; Fixed bracket 2 is installed on the platform 1; Support beam 3 is connected to fixed bracket 2; Stator 4 is mounted on support beam 3, and the side surface of stator 4 is machined with a predetermined roughness. Rotor 5 is coaxially sleeved outside stator 4. There is a gap between the inner wall of rotor 5 and the side of stator 4 to form an annular space for accommodating blood. Drive source 6 is connected to stage 1, and the output shaft of drive source 6 is coaxially connected to rotor 5.

[0022] This invention discloses a blood shearing device with a modular design, allowing for flexible switching of material types and surface conditions. This avoids experimental result biases caused by fixed materials and limited roughening areas in traditional devices. Researchers can quickly replace the stator 4 with different materials and surface treatments according to experimental needs, comparing the effects of different materials and surface treatments on blood compatibility under the same flow field conditions, significantly improving the comparability and repeatability of experiments. It overcomes the limitation of existing technologies that can only study a single factor, enabling simultaneous adjustment of material surface roughness and wettability. This innovative design allows researchers to comprehensively and systematically explore the combined effects of these two key factors on blood compatibility, providing a richer perspective for a deeper understanding of the interaction mechanism between blood and material surfaces. By simultaneously changing surface roughness and wettability, the flow environment of blood in actual medical devices can be simulated more realistically, thereby more accurately assessing the blood compatibility of materials and providing more comprehensive experimental evidence for the screening and optimization of medical device materials.

[0023] This research provides experimental evidence for material selection and surface optimization in blood-contact medical devices such as artificial heart pumps, ECMO machines, and hemodialysis machines, and has extremely high application value. By accurately assessing the blood compatibility of materials, more suitable materials can be selected for the manufacture of medical devices. Simultaneously, surface optimization of materials can reduce the risk of clinical complications and improve the safety and effectiveness of medical devices. This will help promote the development of artificial organs and blood purification technologies, bringing better treatment outcomes and quality of life to patients, and has significant social and economic implications.

[0024] Specifically, stator 4 and rotor 5 are the core components of the device, much like key components in an artificial heart, playing an indispensable role in maintaining blood flow. The cylindrical side surface of stator 4 undergoes meticulous roughening to investigate the impact of roughness on erythrocyte and VWF damage by altering the roughness of the blood-contact surface. To ensure good blood compatibility on the blood-contact surface during device operation, stator 4 is typically made from a test material with excellent blood compatibility, manufactured using advanced 3D printing technology or precision machining processes, thereby minimizing potential adverse effects during blood flow, such as blood coagulation or damage. Rotor 5, as the rotating part of the device, is responsible for driving the blood circulation within the device, and its importance is self-evident. Like the stator, rotor 5 is also 3D printed using the same test material to ensure the consistency of the entire device's performance. In actual operation, the gap between rotor 5 and stator 4 is designed with extreme precision, typically controlled within a very small range. This improves the device's operating efficiency while effectively preventing blood damage and ensuring the accuracy of experimental results.

[0025] To meet the rotational shearing conditions required for the experiment and ensure stable operation, in this embodiment, a 750W brushless DC motor with dimensions of approximately 120mm × 80mm is selected as the drive source 6. This motor has a speed range of 0-8000RPM and a shaft diameter of 14mm. For the coupling 7, a perforated coupling is selected. This coupling 7 has a simple structure, is easy to disassemble, and can effectively compensate for relative misalignment between the two shafts. The perforated coupling has an outer diameter of 30mm, a length of 42mm, and inner diameters of 14mm and 15mm at both ends. The motor shaft and rotor 5 are secured by tightening screws to ensure a stable connection.

[0026] Reference Figure 1 and Figure 2 As shown, the stage 1 further includes a base plate 11 and support legs 12. Four support legs 12 arranged in a positive direction are connected to one side of the base plate 11 by fasteners, and each support leg 12 is coaxially connected to a support foot at its end away from the base plate 11. Specifically, the stage 1, as a key component in the experimental device, is mainly used to support important components such as the drive source 6 (motor), rotor 5, stator 4, and fixed bracket 2. Due to the large load it bears, the strength and hardness of the material need to be considered in the selection of materials to ensure the stability and durability of the structure. For this reason, ABS (acrylonitrile-butadiene-styrene copolymer), an engineering material with high strength and hardness, is used as the main processing material for the stage 1 to fully meet its usage requirements under high load conditions.

[0027] Furthermore, a central through hole 111 is coaxially formed on the base plate 11. The fixing bracket 2 is coaxially mounted on the side of the base plate 11 away from the support leg 12. The fixing bracket 2 has a through hole 23 coaxial with the central through hole 111. The drive source 6 is connected to the side of the base plate 11 away from the support leg 12. The output shaft of the drive source 6 coaxially passes through the central through hole and the through hole and is connected to the rotor 5. Specifically, the fixing bracket 2 includes two coaxially arranged and parallel fixing plates 21. Multiple connecting parts 22 are vertically connected between the two fixing plates 21, and through holes 23 are coaxially formed on the two fixing plates 21. During installation, one fixing plate 21 is connected to the base plate 11 by fasteners, and the other fixing plate 21 is connected to the support beam 3 by fasteners. The design requirements of the fixing bracket 2 are strict. Its shape and size need to be precise to ensure good fit with components such as the stage 1, motor, coupling 7, rotor 5, and support beam 3. Its main function is to work with the motor to connect the rotor 5 to the support beam 3 via the coupling 7, thereby achieving precise positioning and assembly of the rotor 5 and the stator 4. This ensures that the rotor 5 maintains a stable position during rotation, preventing any positioning deviations caused by vibration or instability, thus guaranteeing the efficient operation of the device. The material used is PA, an engineering material with high strength and hardness.

[0028] Reference Figure 5 As shown, the stator 4 further includes a first body 41 and a first connecting shaft 42. The first body 41 is cup-shaped, and the first connecting shaft 42 is coaxially connected to the bottom surface inside the first body 41. A threaded connection hole 421 is coaxially opened at the end of the first connecting shaft 42 away from the first body 41.

[0029] Reference Figure 4 As shown, the support beam 3 has a U-shaped structure. Each end of the support beam 3 is connected to a connecting lug, which extends in a direction away from each other. Each connecting lug has a first connecting hole 31, which is connected to the fixed bracket 2 via a fastener. Simultaneously, a second connecting hole 32 is located in the middle of the support beam 3, and a bolt is coaxially disposed in the second connecting hole 32. The first connecting shaft 42 is screwed onto the bolt. Specifically, the support beam 3 plays a crucial role in the design of the device. Its main function is to fix the stator 4 and ensure that the stator 4 can be suspended above the rotor 5, forming a precise working clearance. To ensure that the support beam 3 has sufficient strength and stability, PA (polyamide), an engineering material with high strength and hardness, is selected. Specifically, the stator 4 is detachably connected to the support beam 3 by bolts, making installation and disassembly very convenient, thus facilitating the replacement of different stators 4 for experiments.

[0030] Reference Figure 6As shown, the rotor 5 further includes a second body 51 and a second connecting shaft 52. The second body 51 is cup-shaped and is coaxially sleeved outside the first body 41. The second connecting shaft 52 is coaxially connected to the bottom surface of the outer side of the second body 51. The second connecting shaft 52 is connected to the output shaft of the drive source 6 through a coupling 7.

[0031] Furthermore, it also includes a controller, which is connected to the drive source 6.

[0032] Example 2: This invention also discloses a blood compatibility evaluation method, which uses the blood shearing device as described in Example 1 to process the blood to be tested, including the following steps: Step S1: Prepare a set of stators made of hydrophilic material, and make the sides of each stator have different predetermined roughness; Step S2: Prepare another set of stators made of hydrophobic material, and make the roughness of each stator side surface correspond to the roughness of each stator side surface prepared in step S1. Step S3: Conduct experiments using two sets of stators respectively. The experimental steps are as follows: Step S3-1: Inject a predetermined amount of blood to be tested, after anticoagulation treatment, into the annular space formed by the stator and rotor; Step S3-2: Start the drive source to drive the rotor to rotate at a predetermined speed, so that the blood to be tested circulates at a preset shear rate; Step S3-3: Collect blood samples at multiple predetermined time points; Step S3-4: Test the collected blood samples. The test indicators include the level of red blood cell hemolysis and the degree of degradation of von Willebrand factor (VWF). Step S4: Based on the detection results of steps S3-4, analyze the effects of different surface roughness and different wettability materials on erythrocyte hemolysis and VWF degradation.

[0033] Specifically, during the experiment, anticoagulated blood was carefully injected into the annular space of the apparatus, with the injection volume strictly controlled between 5ml and 10ml. Anticoagulation treatment prevented blood from clotting during the experiment, which would affect the accuracy of the results. Precise control of the injection volume ensured consistency of experimental conditions for each attempt, making the results comparable. After blood injection, the motor was started to drive rotor 5 to rotate. The motor speed was precisely controlled to ensure the blood was subjected to a shear rate of 500-5000 s⁻¹. -1The blood circulates under specific conditions. This range of shear rates can simulate various flow states that blood may encounter in actual medical devices, providing diverse experimental conditions for studying the interaction between blood and material surfaces. During the experiment, blood samples were collected through the sampling port at different time points from 0 to 120 minutes. Multi-time-point sampling is a major innovation of this invention, enabling dynamic monitoring of the damage process of blood components, revealing the time dependence of the interaction between blood and material surfaces, and providing richer data support for in-depth research on blood compatibility. The collected blood samples were comprehensively tested, with at least the following two indicators: First, the level of erythrocyte hemolysis, determined by measuring the concentration of free hemoglobin in plasma. An increase in the concentration of free hemoglobin in plasma is an important marker of erythrocyte hemolysis; by accurately measuring this indicator, the degree of damage to erythrocytes during the experiment can be accurately assessed. Second, the degree of degradation of von Willebrand factor (VWF), with the retention rate of high molecular weight VWF detected by immunoblotting. Vapor-free fiber (VWF) plays a crucial role in the coagulation process, and its degradation level reflects the impact of the device surface on the coagulation system. Immunoblot analysis can accurately detect VWF degradation, providing important reference for assessing blood compatibility. Based on different combinations of stator materials, surface roughness, and wettability, the dynamic effects on blood component damage were systematically analyzed, establishing a model of the relationship between material surface properties and blood compatibility. Through in-depth analysis and modeling of a large amount of experimental data, the intrinsic connection between material surface properties and blood compatibility can be more intuitively understood, providing a scientific theoretical basis for the screening and optimization of medical device materials.

[0034] The experimental method of this invention not only detects erythrocyte hemolysis but also simultaneously assesses the degradation of plasma proteins (especially high molecular weight VWF). This multi-indicator detection method can more realistically reflect the overall damage pattern of blood components under the action of artificial surfaces, avoiding the one-sidedness of relying on a single indicator to assess blood compatibility. Erythrocyte hemolysis and VWF degradation reflect the damage of different components in the blood, respectively. Simultaneous detection of these two indicators can comprehensively understand the impact of blood-material surface interaction on the coagulation system, hemostasis mechanism, and erythrocyte function, providing a more reliable basis for the safety assessment of medical devices. Furthermore, it enables dynamic tracking of the blood component damage process, rather than just endpoint analysis at a single time point. The interaction between blood and material surfaces is a dynamic process; the degree and mechanism of blood component damage may change over time. The dynamic monitoring capability of this invention can capture these changes, deeply revealing the development process of blood damage and providing strong support for the development of targeted prevention and treatment measures. By analyzing blood samples at different time points, the initial stage, development trend, and final degree of blood damage can be understood, providing more timely suggestions for optimizing the design and use of medical devices.

[0035] The following is a specific experimental example: Stator 4 Fabrication - Representative materials for stator 4 were selected: hydrophilic PMMA (polymethyl methacrylate) and hydrophobic PTFE (polytetrafluoroethylene). To investigate the effect of different roughnesses on blood components, special treatments were applied to the sides of stator 4 using these two materials. A sandblasting process was employed, and by precisely controlling the sandblasting parameters, surfaces with different roughnesses (Ra=0.4μm, Ra=0.6μm, Ra=1.0μm) were prepared. 360° circumferential uniform roughening was achieved, ensuring the consistency and repeatability of surface roughness.

[0036] Blood sample preparation - 400 mL of fresh porcine arterial blood was collected from healthy pigs. Pigs share some physiological similarities with humans, making their blood valuable for relevant research. Immediately after collection, 2% heparin sodium was added for anticoagulation. Rigorous testing ensured that the ACT (activated clotting time) was >300 s to prevent blood clotting during the experiment and guarantee the reliability of the results.

[0037] Experimental Procedure - The experiment was conducted under strictly controlled conditions, with the temperature maintained at 25 degrees Celsius. This temperature is close to the physiological temperature of the human body and can better reflect the actual state of blood within the body. The motor drives rotor 5 to rotate at a speed of 300 rpm, which, after precise calculation, corresponds to a shear rate of 1000 s⁻¹. -1 Under these conditions, blood circulated continuously within the device for 5 hours. To achieve dynamic monitoring of the blood component damage process, samples were taken at 0 min, 30 min, 60 min, 90 min, and 120 min to obtain blood samples at different time points for subsequent comprehensive testing and analysis.

[0038] Detection - Free hemoglobin (pfHb) was determined by sodium carbonate absorbance method to detect the level of erythrocyte hemolysis. The length of the multimeric band of high molecular weight VWF was detected by SDS-agarose immunoblotting and chemiluminescence imaging, and the degradation rate was calculated.

[0039] Experimental results: For hydrophilic PMMA, the contact angle decreases (50°→41.8°) when the roughness increases (0.4→1.0μm), indicating that roughening enhances wettability; for hydrophobic PTFE, the contact angle increases (103.8°→111°) when the roughness increases, indicating that roughening enhances hydrophobicity.

[0040] Red blood cell hemolysis: Hemolysis worsened over time. When using a stator made of hydrophilic PMMA, the hemolysis indices at 120 min were 0.22%, 0.46%, and 0.43%, respectively. Under the same conditions, the hemolysis was more severe with a stator made of hydrophobic PTFE, with indices of 0.53%, 0.95%, and 0.89% at 120 min. This indicates that a hemolysis threshold exists within the stator roughness range of 0.6 μm–1.0 μm, and that hydrophobic surfaces are more prone to causing hemolysis than hydrophilic surfaces.

[0041] VWF degradation: On PMMA surfaces, the VWF degradation rates of the Ra=0.6μm and 1.0μm groups were significantly higher than those of the 0.4μm group, suggesting a threshold range of 0.4–0.6μm. On PTFE surfaces, the 0.6μm group exhibited the fastest degradation rate in the early stages, while the 1.0μm group tended to stabilize in the later stages. Under the same Ra conditions, VWF degradation on PTFE surfaces was significantly lower than that on PMMA surfaces.

[0042] Experimental conclusion: The coupling effect of surface roughness and wettability: Surface roughness and wettability do not affect blood damage independently, but rather exhibit a significant coupling effect. This coupling effect makes the interaction between blood and material surfaces more complex, and the combined influence of these two factors must be considered when studying blood compatibility.

[0043] The different effects of hydrophilic and hydrophobic surfaces: hydrophobic surfaces exacerbate hemolysis of erythrocytes, causing greater damage to their structure and function; while hydrophilic surfaces accelerate VWF degradation, affecting the normal function of key proteins in the coagulation system. This indicates that the damage mechanisms of materials with different hydrophilicity and hydrophobicity to blood components differ. In the selection and design of medical device materials, it is necessary to comprehensively consider the hydrophilicity and hydrophobicity of the material surface according to specific needs. Within the roughness range of 0.6–1.0 μm, there is a significant threshold effect in the damage to blood components.

[0044] Furthermore, in steps S3-4, the level of erythrocyte hemolysis is determined by plasma free hemoglobin concentration, and the degree of degradation of von Willebrand factor (VWF) is detected by immunoblotting to determine the retention rate of high molecular weight VWF.

[0045] Furthermore, in steps S1 and S2, three stators are prepared respectively, and the roughness of the circumferential surface of each stator is Ra=0.4um, Ra=0.6um and Ra=1.0um respectively.

[0046] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A blood shearing device, characterized in that: include, Stage; A fixed bracket is mounted on the platform. A support beam, which is connected to the fixed bracket; The stator is mounted on the support beam, and the side surface of the stator is machined with a predetermined roughness. The rotor is coaxially sleeved outside the stator, and there is a gap between the inner wall of the rotor and the side of the stator to form an annular space for accommodating blood. A drive source is connected to the platform, and the output shaft of the drive source is coaxially connected to the rotor.

2. The blood shearing device according to claim 1, characterized in that: The stage includes a base plate and support legs. Four support legs arranged in a positive direction are connected to one side of the base plate by fasteners, and each support leg is coaxially connected to a support foot at the end away from the base plate.

3. The blood shearing device according to claim 2, characterized in that: A central through hole is coaxially formed on the substrate. The fixing bracket is coaxially mounted on the side of the substrate away from the support leg. A through hole coaxial with the central through hole is formed on the fixing bracket. The drive source is connected to the side of the substrate away from the support leg. The output shaft of the drive source coaxially passes through the central through hole and the through hole and is connected to the rotor.

4. The blood shearing device according to claim 1, characterized in that: The stator includes a first body and a first connecting shaft. The first body is cup-shaped, and the first connecting shaft is coaxially connected to the bottom surface inside the first body. A threaded connection hole is coaxially opened at the end of the first connecting shaft away from the first body.

5. The blood shearing device according to claim 4, characterized in that: The support beam has a U-shaped structure. Each end of the support beam is connected to a connecting lug, and the two connecting lugs extend in a direction away from each other. Each of the two connecting lugs has a first connecting hole and is connected to a fixed bracket at the first connecting hole by a fastener. At the same time, a second connecting hole is opened at the middle of the support beam. A bolt is coaxially arranged in the second connecting hole, and the first connecting shaft is screwed onto the bolt.

6. The blood shearing device according to claim 4, characterized in that: The rotor includes a second body and a second connecting shaft. The second body is cup-shaped and coaxially sleeved outside the first body. The second connecting shaft is coaxially connected to the bottom surface of the outer side of the second body. The second connecting shaft is connected to the output shaft of the drive source through a coupling.

7. The blood shearing device according to claim 1, characterized in that: It also includes a controller connected to the drive source.

8. A method for evaluating blood compatibility, comprising processing the blood to be tested using the blood shearing device as described in any one of claims 1-7, characterized in that: Includes the following steps: Step S1: Prepare a set of stators made of hydrophilic material, and make the sides of each stator have different predetermined roughness; Step S2: Prepare another set of stators made of hydrophobic material, and make the roughness of each stator side surface correspond to the roughness of each stator side surface prepared in step S1. Step S3: Conduct experiments using two sets of stators respectively. The experimental steps are as follows: Step S3-1: Inject a predetermined amount of blood to be tested, after anticoagulation treatment, into the annular space formed by the stator and rotor; Step S3-2: Start the drive source to drive the rotor to rotate at a predetermined speed, so that the blood to be tested circulates at a preset shear rate; Step S3-3: Collect blood samples at multiple predetermined time points; Step S3-4: The collected blood samples are tested, including the level of erythrocyte hemolysis and the degree of degradation of von Willebrand factor (VWF). Step S4: Based on the detection results of steps S3-4, analyze the effects of different surface roughness and different wettability materials on erythrocyte hemolysis and VWF degradation.

9. The blood compatibility evaluation method according to claim 8, characterized in that: In steps S3-4, the level of erythrocyte hemolysis is determined by plasma free hemoglobin concentration, and the degree of degradation of von Willebrand factor (VWF) is detected by immunoblotting to determine the retention rate of high molecular weight VWF.

10. The blood compatibility evaluation method according to claim 8, characterized in that: In steps S1 and S2, the roughness of the circumferential surface of each stator is in the range of 0.2 μm to 1.2 μm.

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