Model system, method, and media for simulating a heart valve based on a non-ideal diode
By establishing a cross-domain physical analogy between fluid systems and circuit systems, a non-ideal diode valve model is constructed, which solves the problems of high computational cost and poor numerical stability in existing heart valve simulations, and realizes efficient and stable multi-cycle simulation and personalized medical support.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WEIFANG UNIVERSITY
- Filing Date
- 2026-03-13
- Publication Date
- 2026-05-29
AI Technical Summary
Existing methods for simulating heart valves are computationally expensive and have poor numerical stability, making it difficult to conduct long-term cardiac cycle simulations and parameterization studies. Furthermore, existing methods for obtaining hemodynamic parameters are invasive, difficult to operate, and cannot be widely adopted.
By establishing a cross-domain physical analogy between fluid systems and circuit systems, a non-ideal diode valve model is constructed. The mathematical expression of the non-ideal diode is used to describe the "pressure-flow" relationship of the valve. Combined with the valve dynamics equation, the personalized calibration of model parameters and the coupled calculation of CFD solver are realized.
It achieves a 1-2 order of magnitude improvement in computational efficiency, strong numerical stability, and can perform high-resolution, multi-cycle simulations on ordinary workstations. It supports simulations of various pathological states, adapts to personalized medical needs, and improves the accuracy and flexibility of simulations.
Smart Images
Figure CN122117425A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a model system, method, and medium for simulating heart valves based on non-ideal diodes, belonging to the fields of computational fluid dynamics and cardiovascular system modeling technology. Background Technology
[0002] Heart valve disease is a common cardiovascular disease that seriously threatens human health. Accurate simulation of heart valve function is crucial for disease diagnosis, treatment planning, and surgical evaluation. Although traditional fluid-structure coupling simulation methods can accurately describe valve behavior, their high computational cost and poor numerical stability limit their widespread application in clinical research and engineering design.
[0003] Existing methods for simulating heart valves often employ complex fluid-structure coupling techniques, requiring the solution of solid mechanics and fluid mechanics equations and the handling of dynamic mesh variations. This results in high computational complexity, making long-term cardiac cycle simulations and parametric studies difficult. Furthermore, these methods are resource-intensive, hindering the achievement of high-resolution, multi-cycle cardiac simulations on ordinary workstations.
[0004] In determining hemodynamic parameters, traditional methods such as obtaining arterial pressure waveforms during diastole and systole, ultrasound, and electrical impedance tomography (EIT) or reactance spectroscopy suffer from invasiveness, high operational difficulty, and low efficiency, hindering their widespread clinical application. For example, patent application CN118609767A discloses a method and apparatus for determining hemodynamic parameters. This method uses feature analysis to find models corresponding to similar vascular segments, samples raw medical data, and inputs it into the model for optimization and training to determine parameters, thus reducing operational difficulty and improving accuracy and efficiency to some extent. However, existing technologies still have many shortcomings: three-dimensional model hemodynamic simulation consumes significant computational resources; machine learning methods lack accuracy and interpretability; simplified 0-dimensional models or circuit-like models have insufficient computational accuracy, making it difficult to obtain some key parameters; and AI models that directly solve for PDEs have poor generalization ability and are time-consuming.
[0005] In the field of heart valve function simulation, there is still a lack of a computationally efficient, numerically stable model with clearly defined physical meanings of parameters that can simulate various pathological states, making it difficult to meet the clinical and engineering needs for accurate simulation of heart valves. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a model system, method, and medium for simulating heart valves based on non-ideal diodes. By establishing a profound physical analogy between fluid systems and circuit systems, and utilizing the mathematical expression of non-ideal diodes, a valve model that is computationally efficient, numerically stable, has clearly defined physical meanings for its parameters, and can simulate various pathological states is constructed.
[0007] The method for implementing a model of a heart valve based on a non-ideal diode, as described in this invention, includes the following steps: S1: Establish cross-domain physical parameter analogy relationships, draw analogies between fluid dynamics systems and circuit systems, and define the physical location of the heart valve as a two-dimensional simulation interface; S2: Construct a mathematical model of a non-ideal diode valve and define a constitutive equation describing the "pressure-flow" relationship of the valve; S3: Construct valve dynamics equations to describe the changes in leaflet angle by integrating valve forces and motion mechanisms; S4: Physiological calibration and personalization of model parameters, adjusting parameters based on clinical data to suit normal or pathological conditions; S5: Integrate the valve model into the CFD solver and achieve coupled calculation, outputting hemodynamic and valve function indicators.
[0008] Preferably, the cross-domain physical parameter analogy relationship in step S1 is as follows: The instantaneous pressure upstream and downstream of the valve interface is analogous to the voltage in a circuit. The instantaneous flow rate at the valve interface is analogous to the current in a circuit. The obstruction of blood flow by valves is analogous to the resistance in a circuit. The inertia of a valve to blood flow is analogous to the inductance in a circuit. The heart valve is considered as a fluid diode, exhibiting low impedance under forward pressure difference and high impedance under reverse pressure difference.
[0009] Preferably, the core mathematical expression of the non-ideal diode valve model in step S2 is: ; in, Indicates the instantaneous flow rate through the valve interface, in m³ / s or mL / s; Indicates the instantaneous pressure upstream of the valve interface, in Pa or mmHg; Indicates the instantaneous pressure downstream of the valve interface, in Pa or mmHg; Indicates the instantaneous pressure difference across the valve interface, in Pa or mmHg; It represents the angle between the leaflet root and the valve cross-section during valve movement, reflecting the orifice area after the valve opens. The larger the value, the more flow rate passes through the valve. This indicates the maximum angle between the leaflet root and the valve cross-section after the valve is fully open; This indicates the valve's inertia in response to blood flow; This indicates blood flow resistance, the obstruction of blood flow by the valve; This represents the flow separation coefficient.
[0010] Preferably, the expression for the valve dynamics equation in step S3 is: ; in, This represents the inertial momentum of the valve; The torque generated by the pressure difference is proportional to the normal component of the pressure difference on the leaflet surface: ; The frictional torque caused by the resistance of the leaflet tissue is proportional to the angular velocity of the leaflet. ; The dynamic torque of the valve leaflets is proportional to the normal component of the valve surface flow rate. ; The eddy current torque in heart valve dynamics is constructed as the product of flow rate and leaflet angle position: ; in, , , , This is the proportionality coefficient; The equilibrium of the valve dynamics equations is constrained as follows: ; in, This is the minimum angle between the leaflet root and the valve cross-section after the valve is completely closed.
[0011] Preferably, step S4 specifically includes the following sub-steps: S41: Parameter classification and clarification of physiological meaning: The model parameters are classified into structural parameters, fluid parameters, and dynamic scaling factors; S42: Parameter inversion and optimization based on clinical data: Numerical optimization algorithms are used to invert and identify parameters, minimizing the error between simulation and measured data; S43: Parameter adjustment strategy under pathological conditions: Establish parameter adjustment rules for pathological conditions; S44: Model Validation and Uncertainty Quantification: Evaluate the predictive ability of the model through cross-validation and uncertainty quantification; S45: Automated calibration interface integrated into the CFD platform: Develop an automated interface to support the import of clinical data and automatic parameter calibration.
[0012] Preferably, the specific rules for adjusting the pathological state parameters in step S43 are as follows: Stenosis model: Increase blood flow resistance and flow separation coefficient The maximum angle between the leaflet root and the valve cross-section after the valve is fully open. ; Regurgitation model: The minimum angle between the leaflet root and the valve cross-section after the valve is fully closed. And appropriately reduce blood flow resistance under reverse pressure gradient. To simulate incomplete closure; Calcification / fibrosis model: Increase the scaling factor and the inertial momentum of the valve Simulates slowed leaflet movement; Prolapse / Flare Model: Adjustment The proportionality coefficient in Alternatively, asymmetric parameters can be introduced to simulate the effects of abnormal eddies.
[0013] Preferably, the coupling calculation process in step S5 is as follows: S51: Define the valve interface in the CFD solver and establish a real-time data exchange mechanism between the fluid domain and the valve model. S52: Valve Model Call: Extract Pressure at the Valve Interface and Substitute the data into the valve mathematical model and solve using implicit or explicit time integration methods. and ; S53: Boundary condition update: update the calculated boundary conditions The interface flow condition is fed back to the CFD solver to update the velocity distribution at the interface; if the valve is in a fully closed or open state, an approximate no-slip boundary condition is applied to simulate the flow obstruction effect. S54: Convergence judgment: Perform local iteration within the current time step until the residual between the valve model output and the CFD flow field meets the preset tolerance, ensuring the numerical stability of the coupled system. S55: Coupled Output and Post-processing: Outputs key valve parameters in real time during the simulation.
[0014] Preferably, the following strategy is used in step S5 to ensure numerical stability: Employ sub-iterative coupling or strongly coupled algorithms; Linearization or Newton-Raphson iteration can be used to process the nonlinear terms; The time step Δt is dynamically adjusted, and the step size is reduced during the rapid opening and closing phase of the valve.
[0015] The model system for simulating heart valves based on non-ideal diodes as described in this invention includes: Analogy Relationship Establishment Module: Used to construct cross-domain parametric mappings between fluid and circuit systems; Mathematical model building module: used to generate constitutive equations for non-ideal diode valves; Parameter calibration module: used to optimize model parameters based on clinical data; CFD coupling module: used to achieve bidirectional coupling between the valve model and the CFD solver.
[0016] The present invention discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the model implementation method based on a non-ideal diode to simulate a heart valve.
[0017] Compared with existing technologies, the model system, method, and medium of the present invention based on non-ideal diodes to simulate heart valves have the following advantages: 1. Improved computational efficiency: It completely avoids the solid solver and dynamic mesh technology required by FSI, reducing the computational cost by 1-2 orders of magnitude, making it possible to perform high-resolution, multi-cycle cardiac simulations on ordinary workstations, which greatly promotes the design iteration and parameterization research process related to heart valves.
[0018] 2. Excellent numerical stability: The model itself is an explicit, algebraic constitutive equation, without complex differential equation solutions and strongly coupled iterative processes. This fundamentally avoids the numerical divergence problem common in FSI, making the simulation extremely robust. During long-term simulations, it can maintain stable calculation results, providing a reliable basis for clinical research and engineering design.
[0019] 3. Profound physical intuition and flexibility: The model directly captures the core function of the valve as a "one-way valve." Each parameter has a clear physical meaning, allowing engineers and researchers to intuitively understand and adjust the model's behavior, flexibly simulating a wide range of states from normal to various pathological conditions. For example, for different pathological states such as valvular stenosis, regurgitation, calcification / fibrosis, prolapse / flail, etc., simply modifying the model parameters according to the corresponding parameter adjustment rules can accurately simulate valve function under these pathological conditions. In contrast, some simplified 0-dimensional models or circuit-like models, although computationally efficient, are difficult to accurately simulate complex pathological states because they ignore some physical details.
[0020] 4. Easy to implement and integrate: The model is simple and does not require modification of the core code of the CFD solver. It can usually be implemented through user-defined functions, scripts or configuration files, with high compatibility and easy to promote and use.
[0021] 5. Facilitating Personalized Medicine: Model parameters can be extracted and calibrated from routine clinical examinations (such as ultrasound), providing a powerful tool for constructing patient-specific cardiac models and using them for surgical planning and prognostic prediction. Compared to traditional general models, this invention better meets the needs of personalized medicine, improving treatment outcomes and patients' quality of life. Attached Figure Description
[0022] Figure 1 : A schematic diagram of the main steps of the non-ideal diode simulation heart valve method in this embodiment of the invention; Figure 2 : A schematic diagram of the valve model and leaflet stress analysis based on a non-ideal diode in this embodiment of the invention; Figure 3 : A flowchart of physiological calibration of model parameters and model personalization in this embodiment of the invention; Figure 4 : Flowchart of CFD solver coupling calculation in an embodiment of the present invention; Figure 5 : A comparison diagram of the periodic changes of the mitral valve in a stenotic state and a normal state in an embodiment of the present invention; in the figure, (a) is the angle of the leaflet root; (b) is the transvalvular pressure gradient; (c) is the valve flow rate; (d) is the valve velocity; Figure 6 : A comparison diagram of the periodic changes of aortic valve regurgitation state and normal state in the embodiments of the present invention; in the figure, (a) is the angle of the leaflet root; (b) is the transvalvular pressure gradient; (c) is the valve flow rate; (d) is the left ventricular volume. Detailed Implementation
[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0024] Example 1: like Figure 1 As shown, this embodiment discloses a modeling method for simulating heart valves based on non-ideal diodes, including the following steps: S1: Establish cross-domain physical parameter analogy relationships, draw analogies between fluid dynamics systems and circuit systems, and define the physical location of the heart valve as a two-dimensional simulation interface; S2: Construct a mathematical model of a non-ideal diode valve and define a constitutive equation describing the "pressure-flow" relationship of the valve; S3: Construct valve dynamics equations to describe the changes in leaflet angle by integrating valve forces and motion mechanisms; S4: Physiological calibration and personalization of model parameters, adjusting parameters based on clinical data to suit normal or pathological conditions; S5: Integrate the valve model into the CFD solver and achieve coupled calculation, outputting hemodynamic and valve function indicators.
[0025] like Figure 2 As shown, a non-ideal diode connected in series with a resistor and an inductor is used to simulate the fluid characteristics of a heart valve, and a strict physical parameter analogy relationship is established between the valve's hydrodynamic system and the circuit system: Instantaneous pressure upstream of the valve interface Analogy to voltage ; Instantaneous pressure downstream of the valve interface Analogy to voltage ; Instantaneous pressure difference across the valve interface Analogous to the potential difference in a circuit ; Instantaneous flow through the valve interface Analogous to the current in a circuit ; The obstruction of blood flow by the valve itself can be likened to the resistance in a circuit. ; The inertia of the valve itself in relation to blood flow can be likened to the inductance in a circuit. .
[0026] Based on this analogy, the heart valve is naturally considered as a fluid diode. Using the classic current-voltage characteristic equation of a non-ideal diode in semiconductor physics, and with adaptive modifications and extensions, the Kirchhoff voltage equation is constructed as follows:
[0027] in, It is a time-varying variable, indicating that the switching process of a non-ideal diode has dynamic characteristics. It is about The function represents the nonlinear characteristics of a nonideal diode. Combined with the valve's opening and closing characteristics, and They are represented as follows:
[0028]
[0029] Based on the above analogy, an equivalent constitutive equation describing the "pressure-flow" relationship of the valve can be defined as follows:
[0030] The physical meaning and function of each parameter are as follows: Instantaneous flow rate through the valve interface (unit: mL / s).
[0031] Instantaneous pressure upstream of the valve interface (unit: mmHg).
[0032] Instantaneous pressure downstream of the valve interface (unit: mmHg).
[0033] Instantaneous pressure difference between upstream and downstream of the valve interface (unit: mmHg).
[0034] The angle between the leaflet root and the valve cross-section during valve movement reflects the orifice area after the valve opens. The larger the value, the greater the flow rate through the valve.
[0035] The maximum angle between the leaflet root and the valve cross-section after the valve is fully open.
[0036] The valve itself has inertia in relation to blood flow.
[0037] Blood flow impedance reflects the obstruction of blood flow by the valve itself.
[0038] : Flow separation coefficient.
[0039] By considering the blood-valve interaction and the valve's movement mechanism, the process of the valve opening from closure to full opening was determined. The changes in valve pressure are determined by multiple factors. These factors include: the pressure gradient between the upstream and downstream of the valve; the frictional effect of resistance from adjacent tissues; the dynamic motion of blood acting on the valve leaflets; and the vortex effect of the valve.
[0040] The torque generated by the pressure difference is proportional to the normal component of the pressure difference on the leaflet surface:
[0041] The frictional torque caused by the resistance of the valve leaflet tissue is proportional to the angular velocity of the valve leaflet.
[0042] The dynamic torque of the valve leaflets is proportional to the normal component of the valve surface flow rate:
[0043] Eddy currents are a crucial factor controlling valvular dynamics. The eddy current torque in cardiac valvular dynamics is constructed as the product of flow rate and leaflet angle position:
[0044] in, , , , This is the proportionality coefficient.
[0045] The equilibrium of the valve dynamics equations is constrained as follows:
[0046] in, This is the minimum angle between the leaflet root and the valve cross-section after the valve is completely closed.
[0047] By combining the interaction forces among the above factors, the valve dynamics equation is constructed:
[0048] in, This represents the inertial momentum of the valve.
[0049] Please see Figure 3 The steps for physiological calibration of model parameters and model personalization include: S41: Parameter classification; S42: Parameter Inversion and Optimization; S43: Personalized Model; S44: Personalized model validation; S45: Integrated into the CFD platform; The parameters are divided into three categories: structural parameters, fluid parameters, and dynamic proportionality coefficients. , , These are structural parameters, primarily determined by the valve's geometry. , , These are fluid parameters that reflect blood flow inertia, valve impedance, and flow separation effects. , , , The proportionality coefficient represents the relationship between the force on the leaflet and its motion response. The least squares method is used to invert and identify the model parameters, and the model parameters are individually optimized and calibrated by minimizing the error function between the simulation results and the measured data. Parameters for a normal human body are determined. , , , The value of ) is increased by and Decrease Simulating the pathological state of valvular stenosis, by reducing Increase The pathological state of valvular regurgitation is simulated. The simulation results are compared and analyzed with the patient's clinical condition to verify the feasibility of the model. Finally, the validated personalized model is integrated into the CFD platform.
[0050] Please see Figure 4 A non-ideal diode valve model is integrated as a custom boundary condition into a commercial or open-source CFD solver to achieve bidirectional coupled simulation of hemodynamics and valve dynamics. Specific process: Boundary condition initialization: Assign values to the structural parameters, fluid parameters, and dynamic scaling factors of the valve model.
[0051] CFD flow field solution: Solve the Navier-Stokes equations to obtain the pressure and flow rate for the current step.
[0052] Valve model call: Extract pressure at the valve interface and Substituting the mathematical model of the non-ideal diode valve and the valve dynamics equation, the Runge-Kutta method is used to solve the problem. and .
[0053] Boundary condition update: The calculated boundary conditions are updated. As the interface flow condition is fed back to the CFD solver, the velocity distribution at the interface is updated; if the valve is in a fully closed or open state ( or If the flow is impeded, then an approximate no-slip boundary condition is applied to simulate the flow obstruction effect.
[0054] Convergence judgment: Perform local iterations within the current time step until the residual between the valve model output and the CFD flow field meets the preset tolerance, ensuring the numerical stability of the coupled system.
[0055] Parameter output: Real-time output of key valve parameters, including instantaneous flow rate, during the simulation. Transvalvular pressure gradient Leaflet angle .
[0056] The test data for this embodiment is as follows: Assuming the patient is in normal condition, the parameters of the four valves are shown in Table 1.
[0057] Table 1 Valve Parameters
[0058] To test the effectiveness of the valve model in simulating diseased heart valves, two typical heart valve diseases were simulated: mitral stenosis and aortic regurgitation. In the mitral stenosis modeling, the parameters corresponding to the mitral valve model were... , , The values under normal conditions are respectively changed to , 50°. In aortic regurgitation modeling, the parameters corresponding to the aortic valve model... , The values under normal conditions are respectively changed to 25°.
[0059] See Figure 5 , Figure 5 In the diagram, (a) represents the leaflet root angle; (b) represents the transvalvular pressure gradient; (c) represents valvular flow rate; and (d) represents valvular velocity. Compared to normal conditions, the hemodynamics of the patient with mitral stenosis are significantly altered. During left ventricular diastole, the maximum opening angle of the mitral valve decreases from the normal 75° to 50° in stenosis, which corresponds to the maximum valve opening area also decreasing from the normal 5 cm². 2 The change was consistent with a reduction of approximately 50%. Mitral stenosis did not cause a significant change in the transvalvular pressure gradient, but it led to a reduction in the average flow through the mitral valve throughout the cardiac cycle. Normally, the peak diastolic mitral valve velocity is between 60 cm / s and 130 cm / s, while a peak velocity exceeding 150 cm / s suggests possible stenosis. In this case, the peak mitral valve velocity was approximately 160 cm / s, further supporting the presence of mitral stenosis.
[0060] See Figure 6 , Figure 6 (a) shows the leaflet root angle; (b) shows the transvalvular pressure gradient; (c) shows the valve flow rate; and (d) shows the valve velocity. Compared with the normal condition, the hemodynamics under aortic regurgitation also showed significant changes. During left ventricular diastole, the minimum aortic valve closure angle increased from the normal 5° to 25°, indicating the presence of aortic regurgitation and regurgitation. Aortic regurgitation did not cause a significant change in the transvalvular pressure gradient, but the aortic valve flow rate remained below 0 mL / s during diastole, suggesting that blood flow continued to flow backward from the aorta into the left ventricle. This regurgitation effect caused the left ventricular end-diastolic volume to increase from the normal 120 mL to approximately 135 mL.
[0061] Example 2: The model system for simulating heart valves based on non-ideal diodes described in this invention, applied to the model method for simulating heart valves based on non-ideal diodes as described in Example 1, includes: Analogy Relationship Establishment Module: Used to construct cross-domain parametric mappings between fluid and circuit systems; This module is responsible for constructing cross-domain parametric mappings between fluid and circuits. In the CFD simulation domain, the physical location of the target heart valve is defined as one or more two-dimensional simulation interfaces. Analogous relationships are established for pressure and voltage, flow and current, valve resistance and resistance, and valve inertia and inductance, thus treating the heart valve as a fluid diode. For example, for the aortic valve, this module defines its location as a specific two-dimensional interface and establishes the corresponding physical parametric mapping according to the above analogies.
[0062] Mathematical model building module: used to generate constitutive equations for non-ideal diode valves; This module is used to generate the constitutive equation for a non-ideal diode valve. Based on the classic current-voltage characteristic equation of a non-ideal diode in semiconductor physics, it is adaptively modified and extended to construct a mathematical model describing the "pressure-flow" relationship of the valve. The physical meaning and expression of each parameter in the model are determined, such as by analyzing the physiological function and hydrodynamic characteristics of the valve to clarify the meaning and range of values of the parameters.
[0063] Parameter calibration module: used to optimize model parameters based on clinical data; This module optimizes model parameters based on clinical data. First, the parameters are categorized and their physiological significance is clarified. Then, a numerical optimization algorithm is used to invert and identify the parameters, minimizing the error between simulation and measured data. Parameter adjustment rules are established for different pathological states; for example, in a mitral stenosis model, R and L are increased, and limits are imposed. The module assesses the model's predictive capabilities through cross-validation and uncertainty quantification, and develops automated interfaces to support the automatic calibration of parameters by importing clinical data. For example, by importing patient echocardiogram data, the module can automatically calibrate and optimize model parameters.
[0064] CFD coupling module: used to achieve bidirectional coupling between the valve model and the CFD solver.
[0065] This module achieves bidirectional coupling between the valve model and the CFD solver. The calibrated valve model is integrated into the CFD solver, establishing a real-time data exchange mechanism between the fluid domain and the valve model. At each time step, it performs CFD flow field solving, valve model invocation, boundary condition updates, convergence checks, and other operations, outputting hemodynamic and valve function parameters. For example, during the simulation of cardiac diastole and systole, this module continuously interacts with the CFD solver, updating the valve state and hemodynamic parameters in real time.
[0066] Example 3: The computer-readable storage medium of the present invention stores a computer program thereon, which, when executed by a processor, implements the model implementation method for simulating a heart valve based on a non-ideal diode as described in Embodiment 1.
[0067] Computer-readable storage media can be electronic storage devices such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, computer-readable storage media includes non-volatile computer-readable storage media. The computer-readable storage medium has storage space for program code that performs any of the method steps described above. This program code can be read from or written to one or more computer program products. The program code can be compressed, for example, in a suitable form.
[0068] When the processor executes the computer program, it will sequentially perform operations such as establishing cross-domain physical parameter analogies, constructing a non-ideal diode valve mathematical model, constructing valve dynamic equations, physiologically calibrating and personalizing model parameters, and integrating the model into a CFD solver to achieve coupled computation, according to the steps in the method embodiment. For example, the processor will define the location of the heart valve as a two-dimensional simulation interface according to the program instructions, establish physical parameter analogies, construct the corresponding mathematical model and dynamic equations, calibrate and optimize the model parameters using clinical data, integrate the model into the CFD solver for coupled computation, and output relevant parameters and indicators.
[0069] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A modeling method for simulating heart valves based on non-ideal diodes, characterized in that, Includes the following steps: S1: Establish cross-domain physical parameter analogy relationships, draw analogies between fluid dynamics systems and circuit systems, and define the physical location of the heart valve as a two-dimensional simulation interface; S2: Construct a mathematical model of a non-ideal diode valve and define a constitutive equation describing the "pressure-flow" relationship of the valve; S3: Construct the valve dynamics equation to describe the change in leaflet angle by integrating the valve force and motion mechanism; S4: Physiological calibration and personalization of model parameters, adjusting parameters based on clinical data to suit normal or pathological conditions; S5: Integrate the valve model into the CFD solver and achieve coupled calculation, outputting hemodynamic and valve function indicators.
2. The modeling method for simulating heart valves based on non-ideal diodes according to claim 1, characterized in that, The cross-domain physical parameter analogy relationship in step S1 is specifically as follows: The instantaneous pressure upstream and downstream of the valve interface is analogous to the voltage in a circuit. The instantaneous flow rate at the valve interface is analogous to the current in a circuit. The obstruction of blood flow by valves is analogous to the resistance in a circuit. The inertia of a valve to blood flow is analogous to the inductance in a circuit. The heart valve is considered as a fluid diode, exhibiting low impedance under forward pressure difference and high impedance under reverse pressure difference.
3. The modeling method for simulating heart valves based on non-ideal diodes according to claim 2, characterized in that, The core mathematical expression for the non-ideal diode valve model in step S2 is: ； in, This represents the instantaneous flow rate through the valve interface, in cubic meters per second (m³). 3 / s or mL / s; Indicates the instantaneous pressure upstream of the valve interface, in Pa or mmHg; Indicates the instantaneous pressure downstream of the valve interface, in Pa or mmHg; Indicates the instantaneous pressure difference across the valve interface, in Pa or mmHg; It represents the angle between the leaflet root and the valve cross-section during valve movement, reflecting the orifice area after the valve opens. The larger the value, the more flow rate passes through the valve. This indicates the maximum angle between the leaflet root and the valve cross-section after the valve is fully open; This indicates the valve's inertia in response to blood flow; This indicates blood flow resistance, the obstruction of blood flow by the valve; This represents the flow separation coefficient.
4. The method of modeling a heart valve based on a non-ideal diode according to claim 3, wherein, The expression for the valve dynamics equation in step S3 is as follows: ； wherein, is the inertial momentum of the valve; The moment generated by the pressure difference is proportional to the normal component of the pressure difference on the surface of the leaflet: ； The frictional torque caused by the resistance of the leaflet tissue is proportional to the angular velocity of the leaflet. ； The dynamic torque of the valve leaflets is proportional to the normal component of the valve surface flow rate. ； The eddy current torque in heart valve dynamics is constructed as the product of flow rate and leaflet angle position: ； in, , , , This is the proportionality coefficient; The equilibrium of the valve dynamics equations is constrained as follows: ； in, This is the minimum angle between the leaflet root and the valve cross-section after the valve is completely closed.
5. The modeling method for simulating heart valves based on non-ideal diodes according to claim 3, characterized in that, Step S4 specifically includes the following sub-steps: S41: Parameter classification and clarification of physiological meaning: The model parameters are classified into structural parameters, fluid parameters, and dynamic scaling factors; S42: Parameter inversion and optimization based on clinical data: Numerical optimization algorithms are used to invert and identify parameters, minimizing the error between simulation and measured data; S43: Parameter adjustment strategy under pathological conditions: Establish parameter adjustment rules for pathological conditions; S44: Model Validation and Uncertainty Quantification: Evaluate the predictive ability of the model through cross-validation and uncertainty quantification; S45: Automated calibration interface integrated into the CFD platform: Develop an automated interface to support the import of clinical data and automatic parameter calibration.
6. The modeling method for simulating heart valves based on non-ideal diodes according to claim 5, characterized in that, The specific rules for adjusting the pathological state parameters in step S43 are as follows: Stenosis model: Increase blood flow resistance and flow separation coefficient The maximum angle between the leaflet root and the valve cross-section after the valve is fully open. ; Regurgitation model: The minimum angle between the leaflet root and the valve cross-section after the valve is fully closed. And appropriately reduce blood flow resistance under reverse pressure gradient. To simulate incomplete closure; Calcification / fibrosis model: Increase the scaling factor and the inertial momentum of the valve Simulates slowed leaflet movement; Prolapse / Flare Model: Adjustment The proportionality coefficient in Alternatively, asymmetric parameters can be introduced to simulate the effects of abnormal eddies.
7. The modeling method for simulating heart valves based on non-ideal diodes according to claim 3, characterized in that, The coupling calculation process in step S5 is as follows: S51: Define the valve interface in the CFD solver and establish a real-time data exchange mechanism between the fluid domain and the valve model. S52: Valve Model Call: Extract Pressure at the Valve Interface and Substitute the data into the valve mathematical model and solve using implicit or explicit time integration methods. and ; S53: Boundary condition update: update the calculated boundary conditions The interface flow condition is fed back to the CFD solver to update the velocity distribution at the interface; if the valve is in a fully closed or open state, an approximate no-slip boundary condition is applied to simulate the flow obstruction effect. S54: Convergence judgment: Perform local iteration within the current time step until the residual between the valve model output and the CFD flow field meets the preset tolerance, ensuring the numerical stability of the coupled system. S55: Coupled Output and Post-processing: Outputs key valve parameters in real time during the simulation.
8. The modeling method for simulating heart valves based on non-ideal diodes according to claim 7, characterized in that, The following strategy is used in step S5 to ensure numerical stability: Employ sub-iterative coupling or strongly coupled algorithms; Linearization of the nonlinear terms or Newton-Raphson iteration; The time step Δt is dynamically adjusted, and the step size is reduced during the rapid opening and closing phase of the valve.
9. A model system for simulating heart valves based on non-ideal diodes, applied to the modeling method for simulating heart valves based on non-ideal diodes as described in any one of claims 1-8, characterized in that, The system includes: Analogy Relationship Establishment Module: Used to construct cross-domain parametric mappings between fluid and circuit systems; Mathematical model building module: used to generate constitutive equations for non-ideal diode valves; Parameter calibration module: used to optimize model parameters based on clinical data; CFD coupling module: used to achieve bidirectional coupling between the valve model and the CFD solver.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the modeling method for simulating heart valves based on non-ideal diodes as described in any one of claims 1 to 8.