Platelet injury assessment method, device, medium and program product for hemodialysis catheter

Abstract

The invention specifically discloses a platelet injury assessment method and device for a hemodialysis catheter, a medium and a program product, and the method comprises the steps: obtaining the actual structural characteristics and clinical standard size of the hemodialysis catheter, and carrying out the geometric modeling of the hemodialysis catheter; performing high-precision grid division and hemodynamic analog simulation on the geometric model of the hemodialysis catheter; setting boundary conditions of each fluid domain, and establishing a shear stress and vorticity coupled damage evaluation mechanism by introducing vorticity as coupling characterization of local shear stress and eddy current effect; calculating the vortex intensity and shear stress of the blood of the blood flow velocity field through the damage assessment mechanism, and constructing a blood damage model coupled with a time accumulation effect; particle statistical data are obtained through particle tracking in the hemodialysis catheter, and platelet injury calculation is carried out through a blood injury model. The accuracy of platelet injury estimation of the hemodialysis catheter can be improved.

Description

Technical Field

[0001] This invention relates to the technical field of platelet damage assessment in hemodialysis, and more specifically, to a method, device, medium, and procedure for assessing platelet damage in hemodialysis catheters. Background Technology

[0002] The Platelet Damage Index (BDI) is a key indicator for assessing the degree of platelet damage during hemodialysis. It reflects the extent of platelet damage during dialysis and is an important parameter for measuring dialysis effectiveness. A higher BDI value indicates more severe platelet damage, which may have adverse effects on the patient's health. Currently used methods for assessing platelet damage primarily rely on indirect inference based on the operating parameters and biochemical indicators of hemodialysis equipment. Existing technologies for calculating platelet injury index (BDI) largely depend on estimations of parameters such as blood flow velocity and changes in plasma concentration. However, these methods have significant shortcomings: First, most existing BDI assessment models are based on simplified mathematical models, neglecting the spatial distribution characteristics of blood flow and the specific impact of local flow fields on platelet damage, leading to insufficient calculation accuracy. Second, current methods mostly employ static analysis models, failing to effectively incorporate the dynamic changes in blood flow velocity and composition during dialysis, making them ill-suited to individual patient differences and fluctuations in treatment conditions in clinical practice. Furthermore, traditional assessment methods fail to fully integrate catheter structural characteristics, such as tip morphology and side-hole flow velocity distribution, resulting in significant limitations in their application to catheter structure optimization and improving hemodialysis efficiency. Simultaneously, traditional BDI models typically use global averaging or simple integration methods, which cannot accurately characterize the dynamic cumulative effect of local shear rates under complex blood flow configurations, leading to biases in the assessment of blood injury risk. Therefore, accurately assessing platelet damage in hemodialysis catheters to meet the needs of precision medicine is of great significance. Summary of the Invention

[0003] This invention provides a method, device, medium, and procedure for assessing platelet damage in hemodialysis catheters, addressing the problem that existing platelet damage assessment methods for hemodialysis catheters lack accuracy and fail to meet the needs of precision medicine. It can improve the accuracy of platelet damage estimation for hemodialysis catheters and provide theoretical guidance for optimizing the performance of hemodialysis catheters.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for assessing platelet damage in hemodialysis catheters, comprising:

[0006] Obtain the actual structural features and clinical standard dimensions of hemodialysis catheters, and perform geometric modeling of hemodialysis catheters;

[0007] High-precision mesh generation and hemodynamic simulation were performed on the geometric model of the hemodialysis catheter.

[0008] Boundary conditions for each fluid domain are set, and a damage assessment mechanism for the coupling of shear stress and vorticity is established by introducing vorticity as a coupled characterization of local shear stress and vortex effect.

[0009] The damage assessment mechanism is used to calculate the eddy current intensity and shear stress of blood in the blood flow velocity field, and a blood damage model coupled with the time accumulation effect is constructed.

[0010] Particle statistics are obtained by tracking particles within the hemodialysis catheter, and platelet damage is calculated using a blood injury model based on the particle statistics and local hemodynamic parameters.

[0011] Preferably, the geometric modeling includes:

[0012] The hemodialysis catheter was fully parametrically modeled in three dimensions using SolidWorks software, and the catheter body was completely constructed, including the dual flow channel structure of the arterial lumen and venous lumen, the side hole array, and the distal conical tip. The superior vena cava model was also integrated simultaneously.

[0013] Preferably, the high-precision mesh generation and hemodynamic simulation of the geometric model of the hemodialysis catheter includes:

[0014] The computational domain is discretized efficiently using polyhedral mesh elements. Local mesh refinement is implemented in key regions with significant flow gradients, and boundary layer meshes with a set number of layers and thickness are generated at the fluid-solid interface. The key regions include: the side-hole jet region, the inner wall of the cavity, and the tip of the conduit.

[0015] Preferably, the high-precision mesh generation and hemodynamic simulation of the geometric model of the hemodialysis catheter further includes:

[0016] The incompressible Navier-Stokes equations corresponding to the geometric model of the hemodialysis catheter were numerically solved using a laminar flow model to obtain the blood flow velocity field distribution over a complete cycle.

[0017] Preferably, the setting of boundary conditions for each fluid domain includes:

[0018] The superior vena cava inlet is set as a velocity inlet that follows a pulsatile waveform to simulate periodically changing blood flow input;

[0019] The corresponding outlet is set as a pressure outlet with a fixed reference value to characterize the downstream flow environment;

[0020] The properties of the blood material are set as an incompressible Newtonian fluid, with density and dynamic viscosity both selected from typical values ​​of blood;

[0021] Set a fixed time step that is compatible with the flow velocity period, and use a transient solver to capture the dynamic changes in the flow field.

[0022] Preferably, the establishment of the damage assessment mechanism coupling shear stress and eddy current includes:

[0023] A blood viscosity model was constructed, and the functional relationship describing the change of blood viscosity with local shear rate was solved. After obtaining the spatial distribution of local shear rate and corresponding viscosity in the whole watershed, the local shear force on the blood was calculated to assess the mechanical load on blood cells and quantify their damage.

[0024] A system for characterizing eddy current intensity was constructed to reflect the true state of platelet dynamics under turbulent blood flow by examining the contribution of coupled rotational effects to platelet deformation, collision probability, and aggregation risk.

[0025] Preferably, the calculation of platelet damage using a blood injury model includes:

[0026] According to the formula: Platelet damage is calculated, where N is the total number of assessment intervals, and a, b, and c are empirical constants. for The flow weighting factor at time τ For time point t j Local shear stress at point Δt j For the corresponding time step, It serves as a model for blood injury.

[0027] The present invention also provides a computer device, the device comprising: a memory and a processor; the memory for storing a computer program; the processor executing the computer program to implement the steps of the method described above.

[0028] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described above.

[0029] This invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the aforementioned method. This invention provides a method, device, medium, and program product for assessing platelet damage in hemodialysis catheters. By introducing eddy current as a coupled representation of local shear stress and eddy current effects, and combining a region weighting factor to enhance the spatial sensitivity of key components such as side holes and tips, a dynamic damage accumulation model is constructed that can simultaneously reflect the time-varying load history and local flow field structural characteristics. This addresses the problem of insufficient accuracy in existing platelet damage assessment methods for hemodialysis catheters, which fails to meet the needs of precision medicine. It improves the accuracy of platelet damage estimation for hemodialysis catheters and provides theoretical guidance for optimizing the performance of hemodialysis catheters. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below.

[0031] Figure 1 This is a schematic diagram of a platelet damage assessment method for hemodialysis catheters provided by the present invention.

[0032] Figure 2 This is a schematic diagram of a platelet damage calculation step for a hemodialysis catheter provided in an embodiment of the present invention. Detailed Implementation

[0033] To enable those skilled in the art to better understand the embodiments of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and implementation methods.

[0034] To address the shortcomings of current platelet damage assessment methods for hemodialysis catheters, which lack accuracy and fail to meet the needs of precision medicine, this invention provides a method, device, medium, and procedure for platelet damage assessment of hemodialysis catheters. This solution improves the accuracy of platelet damage estimation for hemodialysis catheters, providing theoretical guidance for optimizing hemodialysis catheter performance.

[0035] like Figure 1 and Figure 2 As shown, a method for assessing platelet damage in hemodialysis catheters includes:

[0036] S1: Obtain the actual structural features and clinical standard dimensions of the hemodialysis catheter, and perform geometric modeling of the hemodialysis catheter.

[0037] S2: Perform high-precision mesh generation and hemodynamic simulation on the geometric model of the hemodialysis catheter.

[0038] S3: Set the boundary conditions for each fluid domain, and establish a damage assessment mechanism that couples shear stress and vorticity by introducing vorticity as a coupled characterization of local shear stress and vortex effect.

[0039] S4: The blood flow velocity field is used to calculate the eddy current intensity and shear stress of the blood through the damage assessment mechanism, and a blood damage model coupled with the time cumulative effect is constructed.

[0040] S5: By tracking particles within the hemodialysis catheter, particle statistics are obtained, and platelet damage is calculated using a blood injury model based on the particle statistics and local hemodynamic parameters.

[0041] In one embodiment, geometric modeling and mesh generation are achieved through the following steps:

[0042] Parametric geometric modeling: Based on clinical standard dimensions and the actual structural characteristics of hemodialysis catheters, a fully parametric 3D geometric model was performed using the SolidWorks software platform. This resulted in the complete construction of the catheter body, including the dual-channel structure of the arterial and venous cavities, the side-hole array, and the distal tapered tip, while simultaneously integrating the superior vena cava model. This parametric modeling method not only ensures that the dimensions of each part conform to medical device design specifications but also achieves flexible adjustment of key geometric features. This provides a highly controllable and reusable geometric foundation for subsequent parametric fluid dynamics research, guaranteeing the engineering guidance value and clinical relevance of the simulation results from the outset.

[0043] Geometric Repair and Smoothing: After initial geometric construction, the model is imported into the ANSYS Wrap module for geometric repair and surface optimization. This process automatically identifies and stitches together minute gaps on the model surface, eliminates overlapping or interference surfaces, and smooths the transitions between sharp edges and surfaces. This effectively solves non-manifold topology problems that could lead to meshing failures or computational divergences. The repaired model exhibits excellent watertightness and surface continuity, significantly enhancing the robustness of the computational model and laying a solid geometric foundation for subsequent high-fidelity numerical simulations.

[0044] High-precision computational mesh generation: The optimized geometric model is imported into the ANSYS Fluent Meshing module for mesh generation. Polyhedral mesh elements are used to efficiently discretize the computational domain. Local mesh refinement is implemented in key areas with significant flow gradients, such as the side jet region, the inner wall of the lumen, and the tip of the catheter. At the same time, a boundary layer mesh with a reasonable number of layers and thickness is generated at the fluid-solid interface to accurately analyze the velocity distribution and shear stress field in the near-wall region, thereby comprehensively ensuring the accuracy and numerical stability of subsequent hemodynamic simulations.

[0045] This method introduces vorticity as a coupled representation of local shear stress and eddy current effects, and combines a region weighting factor to enhance the spatial sensitivity of key components such as side holes and tips, constructing a dynamic damage accumulation model that simultaneously reflects the time-varying load history and local flow field structural characteristics. The BDI index enhances the ability to identify high-shear regions and rotating flow regions in complex flow fields, thus more realistically simulating the damage evolution process of blood cells in non-uniform and unsteady flow fields. This method is particularly suitable for medical devices with porous reflux and vortex structures, such as hemodialysis catheters, providing a more accurate theoretical tool for blood damage risk assessment and structural optimization.

[0046] Furthermore, the setting of boundary conditions for each fluid domain includes:

[0047] The superior vena cava inlet is set as a velocity inlet that follows a pulsatile waveform to simulate periodically changing blood flow input;

[0048] The corresponding outlet is set as a pressure outlet with a fixed reference value to characterize the downstream flow environment;

[0049] The properties of the blood material are set as an incompressible Newtonian fluid, with density and dynamic viscosity both selected from typical values ​​of blood;

[0050] Set a fixed time step that is compatible with the flow velocity period, and use a transient solver to capture the dynamic changes in the flow field.

[0051] In practical applications, the boundary parameters of the fluid domain are set through the boundary conditions panel in ANSYS Fluent. The settings for each boundary location are shown in Table 1 below:

[0052]

[0053] The superior vena cava inlet was set as a velocity inlet following a pulsating waveform to simulate periodically changing blood flow input; the corresponding outlet was set as a pressure outlet with a fixed reference value to characterize the downstream flow environment. The blood material properties were set as an incompressible Newtonian fluid, with density and dynamic viscosity selected from typical blood values. Finally, a transient solver was used for calculation, with its time step appropriately selected based on the flow characteristics to accurately capture the dynamic changes in the flow field.

[0054] Furthermore, the establishment of the damage assessment mechanism coupled with shear stress and eddy current includes: constructing a blood viscosity model and solving the functional relationship describing the change of blood viscosity with local shear rate; after obtaining the spatial distribution of local shear rate and corresponding viscosity in the entire flow domain, calculating the local shear force on the blood to assess the mechanical load on blood cells and thus quantify their degree of damage.

[0055] A system for characterizing eddy current intensity was constructed to reflect the true state of platelet dynamics under turbulent blood flow by examining the contribution of coupled rotational effects to platelet deformation, collision probability, and aggregation risk.

[0056] Furthermore, hemodynamic simulation is performed on the geometric model of the hemodialysis catheter, including: calculation of the blood flow velocity field;

[0057] In ANSYS Fluent, a laminar flow model is used to numerically solve the incompressible Navier-Stokes equations. The Navier-Stokes equations are in the following form:

[0058] ;

[0059] ;

[0060] In the formula, Let u be the blood density and u be the velocity vector. For pressure, For dynamic viscosity, Represents the local acceleration term. Represents the convective acceleration term. Represents pressure gradient force. It represents viscous force.

[0061] In practical applications, after setting the boundary conditions and the Navier-Stokes equations, the software will discretize the computational domain based on the finite volume method and use a corresponding numerical algorithm (such as SIMPLE) to iteratively solve the discretized equations, finally outputting the velocity distribution of the entire flow field over a complete cycle.

[0062] Furthermore, the eddy current intensity and shear stress of blood are calculated based on the blood flow velocity field, including:

[0063] The local shear rate field within the computational domain is solved based on the velocity field to obtain the local shear rate of the entire flow domain;

[0064] Based on the non-Newtonian blood rheological properties, a blood viscosity model describing the change of blood viscosity with local shear rate was constructed and solved to obtain the corresponding blood viscosity.

[0065] The product of the corresponding dynamic blood viscosity and the local shear rate is used as a characterization of shear stress.

[0066] Specifically, after obtaining the flow field velocity solution, the local shear rate field of the entire flow domain is calculated based on the obtained velocity field data using the ANSYS Fluent post-processing function. First, calculate the strain rate tensor at a point in the fluid based on the velocity field distribution. The specific formula is as follows: In the formula It is a three-dimensional velocity vector. Let be the velocity gradient tensor.

[0067] strain rate tensor The detailed process is as follows:

[0068] first step: ;

[0069] Taking the first row of the matrix as an example, in the formula Let be the rate of change of velocity in the x-direction; The rate of change of velocity in the x-direction with respect to the y-direction; Let be the rate of change of velocity in the x-direction with respect to velocity in the z-direction.

[0070] Step 2 ;

[0071] Step 3:

[0072] ;

[0073] Obtain the strain tensor Its scalar form was then derived based on the principles of fluid mechanics, ultimately based on the following formula: In the formula It is a double dot product.

[0074] The specific steps for calculating the double dot product are as follows:

[0075] ;

[0076] because It is symmetrical, that is The above formula can be simplified to:

[0077] ;

[0078] It measures the total deformation intensity of a fluid element in all possible directions. Substituting into the core formula, we can obtain the complete formula for calculating the local shear rate:

[0079] ;

[0080] After obtaining the local shear rate distribution across the entire watershed, a functional relationship describing the change in blood viscosity with local shear rate was constructed and solved based on non-Newtonian blood rheological properties. An experimentally validated blood viscosity model was adopted, and its mathematical expression is as follows:

[0081] ;

[0082] The values ​​are typically set as follows:

[0083] ;

[0084] That is, the mathematical expression can be simplified to:

[0085] ;

[0086] This model can accurately characterize the typical shear-thinning behavior of blood, which exhibits high viscosity in the low-shear region and low viscosity in the high-shear region.

[0087] Assuming the side-hole jet region The formula for calculating its corresponding viscosity is:

[0088] ;

[0089] The calculated viscosity of the side-hole jet region is approximately Pa·s.

[0090] The precise quantification of this viscosity parameter provides a crucial parameter basis for the subsequent establishment of a recycling rate correction model based on local rheological properties, effectively improving the physiological authenticity and computational accuracy of recycling risk assessment.

[0091] To obtain the local shear rate of the entire watershed and corresponding viscosity After spatial distribution, the rheological properties need to be further converted into mechanical loads, i.e., the local shear stress on the blood needs to be calculated. This step is based on the constitutive relations of non-Newtonian fluids, characterizing the shear stress as the product of dynamic viscosity and local shear rate. The core calculation formula is as follows: In the formula The apparent viscosity of blood as a function of shear rate. This represents the local shear rate corresponding to the spatial location and time step. This formula strictly follows the stress-strain rate relationship of generalized Newtonian fluids, physically characterizing the magnitude of the tangential force per unit area in the flow field. It is a direct input variable for assessing the mechanical load on blood cells and thus quantifying the degree of damage.

[0092] To address the non-Newtonian rheological properties of blood, the Carreau blood viscosity model can be introduced to analyze local shear rates. Real-time viscosity solution This technology enables dynamic coupling calculation of viscosity over time and space. It overcomes the error accumulation problem of the fixed viscosity assumption in traditional models, making the calculation of blood damage factors closer to the real blood biomechanical and physiological characteristics.

[0093] Furthermore, the calculation of blood eddy current intensity and shear stress based on the blood flow velocity field also includes:

[0094] eddy current intensity Vi Defined as the modulus |▽×u| of the curl of the velocity field, according to the formula: Calculate the curl component, where ▽ is the curl operator, and u is the three-dimensional velocity vector, where u x u y u z These represent the components of velocity in the x, y, and z directions of the Cartesian coordinate system, respectively, where i, j, and k are unit vectors in the coordinate directions.

[0095] Therefore, we get: .

[0096] In practical applications, to analyze the characteristics of different regions, the computational domain is generally divided into a side-hole region and a tip region: the corresponding mesh is extracted in the side-hole region and the average eddy current intensity is calculated. The average eddy current intensity is calculated using a mesh near the tip. All eddy current intensity data are averaged over a complete cycle to reflect the steady-state characteristics under periodic pulsating flow conditions.

[0097] The method also includes: constructing a region weighting factor based on the difference in damage contribution in different blood flow spatial regions, and applying the formula: Calculate the traffic weighting factor w, where Q max For maximum flow, Q min k1 and k2 are weighting coefficients for the minimum flow rate.

[0098] In one embodiment, , Take weighting coefficients Substituting into the formula, we get: w=0.6*60+0.4*((4920-1011) / 4920)=36+0.3176≈36.32.

[0099] This method, characterized by significant differences in damage contribution to different blood flow spatial regions, proposes a strategy for constructing regional weighting factors to express the spatial heterogeneity of the blood flow environment. By coupling the hydrodynamic sensitivity of structural features (such as side holes and tip regions), traditional statistical indicators are deepened into a three-dimensional differential sensitivity evaluation system, significantly improving the ability to identify high-risk areas and providing a basis for optimizing the local structure of catheters and other devices.

[0100] Furthermore, the blood damage calculation includes:

[0101] Particle tracking was performed on the movement of particles within the hemodialysis catheter, and particle statistics were obtained.

[0102] A blood injury model based on the cumulative effect of coupling time was constructed, and platelet damage was calculated using the blood injury model based on particle statistics and local hemodynamic parameters.

[0103] Specifically, after obtaining the blood viscosity model and solving the non-Newtonian flow field, the particle motion within the hemodialysis catheter is accurately tracked using the discrete phase model in ANSYS Fluent. Based on the converged flow field data, particle release parameters are set, and tracer particles are released from the catheter venous inlet with initial conditions matching the local flow field. The particle motion follows Newton's second law, and its trajectory is determined by solving the differential equations of motion: In the formula The position vector of the particle describes the instantaneous coordinates of the tracer particle in three-dimensional space; The velocity vector of the particle describes its instantaneous velocity in three-dimensional space.

[0104] Furthermore, platelet damage in the blood is calculated using a blood injury model, including:

[0105] A blood injury integral enhancement model coupled with time-cumulative effects is proposed, overcoming the limitation of traditional blood injury formulas that rely solely on instantaneous values, by introducing a cumulative integral form: Furthermore, a power-law risk amplification process was applied to rigorously quantify the high-shear time-cumulative exposure effect in blood injury assessment. This time-series enhancement mechanism strengthens the ability to capture platelet injury processes under long-path retention and repeatedly disturbed flow.

[0106] According to the formula: The calculation of platelet damage in blood is performed, where N is the total number of assessment intervals, and a, b, and c are empirical constants. for The flow weighting factor at time τ For time point t j Local shear stress at point Δt j For the corresponding time step, It serves as a model for blood injury.

[0107] As can be seen, this method breaks through the limitation of traditional blood injury indicators that rely solely on shear rate as a single dimension, and for the first time incorporates local vorticity. With shear stress τ A blood injury calculation method was jointly introduced to construct an eddy current intensity characterization system. By coupling the rotational effect to the contribution of platelet deformation, collision probability, and aggregation risk, the injury prediction can more comprehensively reflect the true state of platelet dynamics under turbulent blood flow.

[0108] Given the significant differences in the damage contribution of different blood flow spatial regions, a regional weighting factor is proposed. The construction strategy enables the expression of spatial heterogeneity differences in the blood flow environment. By coupling the hydrodynamic sensitivity of structural features (such as side holes and tip regions), traditional statistical indicators are deepened into a three-dimensional differential sensitivity evaluation system, which significantly improves the ability to identify high-risk areas and provides a basis for optimizing the local structure of catheters and other devices.

[0109] Furthermore, the present invention provides a computer device comprising: a memory and a processor; the processor may be an integrated circuit chip having signal processing capabilities. The processor may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, operations, and logic block diagrams disclosed in the embodiments of this disclosure. The general-purpose processor may be a microprocessor or any conventional processor, and may be based on an x86 architecture or an ARM architecture.

[0110] Generally, various exemplary embodiments of the present invention can be implemented in hardware or dedicated circuitry, software, firmware, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. When aspects of embodiments of the present invention are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, apparatuses, systems, techniques, or methods described herein can be implemented as non-limiting examples in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0111] The present invention also provides a computer-readable storage medium, wherein in one embodiment the computer-readable storage medium may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM) used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous interconnected dynamic random access memory (SLDRAM), and direct memory bus random access memory (DR RAM). It should be noted that the memory of the methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0112] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described method. Therefore, this invention provides a method, device, medium, and program product for assessing platelet damage in hemodialysis catheters. By introducing eddy current as a coupled representation of local shear stress and eddy current effects, and combining a region weighting factor to enhance the spatial sensitivity of key components such as side holes and tips, a dynamic damage accumulation model that can simultaneously reflect the time-varying load history and local flow field structural characteristics is constructed. This addresses the problem of insufficient accuracy in existing platelet damage assessment methods for hemodialysis catheters, which fails to meet the needs of precision medicine. It improves the accuracy of platelet damage estimation for hemodialysis catheters and provides theoretical guidance for optimizing the performance of hemodialysis catheters.

[0113] The structure, features, and effects of the present invention have been described in detail above with reference to the embodiments shown in the figures. The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, shall be within the protection scope of the present invention as long as they do not exceed the spirit covered by the specification and figures.

Claims

1. A method for assessing platelet damage in hemodialysis catheters, characterized in that, include: Obtain the actual structural features and clinical standard dimensions of hemodialysis catheters, and perform geometric modeling of hemodialysis catheters; High-precision mesh generation and hemodynamic simulation were performed on the geometric model of the hemodialysis catheter. Boundary conditions for each fluid domain are set, and a damage assessment mechanism for the coupling of shear stress and vorticity is established by introducing vorticity as a coupled characterization of local shear stress and vortex effect. The damage assessment mechanism is used to calculate the eddy current intensity and shear stress of blood in the blood flow velocity field, and a blood damage model coupled with the time accumulation effect is constructed. Particle statistics are obtained by tracking particles within the hemodialysis catheter, and platelet damage is calculated using a blood injury model based on the particle statistics and local hemodynamic parameters.

2. The method for assessing platelet damage in hemodialysis catheters according to claim 1, characterized in that, The geometric modeling includes: The hemodialysis catheter was fully parametrically modeled in three dimensions using SolidWorks software, and the catheter body was completely constructed, including the dual flow channel structure of the arterial lumen and venous lumen, the side hole array, and the distal conical tip. The superior vena cava model was also integrated simultaneously.

3. The method for assessing platelet damage in hemodialysis catheters according to claim 2, characterized in that, The high-precision mesh generation and hemodynamic simulation of the geometric model of the hemodialysis catheter include: The computational domain is discretized efficiently using polyhedral mesh elements. Local mesh refinement is implemented in key regions with significant flow gradients, and boundary layer meshes with a set number of layers and thickness are generated at the fluid-solid interface. The key regions include: the side-hole jet region, the inner wall of the cavity, and the tip of the conduit.

4. The method for assessing platelet damage in hemodialysis catheters according to claim 3, characterized in that, The high-precision mesh generation and hemodynamic simulation of the geometric model of the hemodialysis catheter also includes: The incompressible Navier-Stokes equations corresponding to the geometric model of the hemodialysis catheter were numerically solved using a laminar flow model to obtain the blood flow velocity field distribution over a complete cycle.

5. The method for assessing platelet damage in hemodialysis catheters according to claim 4, characterized in that, The setting of boundary conditions for each fluid domain includes: The superior vena cava inlet is set as a velocity inlet that follows a pulsatile waveform to simulate periodically changing blood flow input; The corresponding outlet is set as a pressure outlet with a fixed reference value to characterize the downstream flow environment; The properties of the blood material are set as an incompressible Newtonian fluid, with density and dynamic viscosity both selected from typical values ​​of blood; Set a fixed time step that is compatible with the flow velocity period, and use a transient solver to capture the dynamic changes in the flow field.

6. The method for assessing platelet damage in hemodialysis catheters according to claim 5, characterized in that, The established damage assessment mechanism that couples shear stress and eddy current includes: A blood viscosity model was constructed, and the functional relationship describing the change of blood viscosity with local shear rate was solved. After obtaining the spatial distribution of local shear rate and corresponding viscosity in the whole watershed, the local shear force on the blood was calculated to assess the mechanical load on blood cells and quantify their damage. A system for characterizing eddy current intensity was constructed to reflect the true state of platelet dynamics under turbulent blood flow by examining the contribution of coupled rotational effects to platelet deformation, collision probability, and aggregation risk.

7. The method for assessing platelet damage in hemodialysis catheters according to claim 6, characterized in that, The calculation of platelet damage using a blood injury model includes: According to the formula: Platelet damage is calculated, where N is the total number of assessment intervals, and a, b, and c are empirical constants. for The flow weighting factor at time τ For time point t j Local shear stress at point Δt j For the corresponding time step, It serves as a blood injury model.

8. A computer device, characterized in that, The device includes: a memory and a processor; the memory is used to store a computer program; the processor executes the computer program to implement the steps of the method according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method as described in any one of claims 1-7.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method described in any one of claims 1-7.

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