Prediction method and system of hemolysis index, electronic equipment and storage medium

Abstract

The embodiment of the invention relates to the technical field of medical instruments, and discloses a hemolysis index prediction method and system, electronic equipment and a storage medium. The hemolysis index prediction method comprises the following steps: determining a flow velocity field and shear stress distribution of a mechanical circulation auxiliary system according to a mechanical structure of the mechanical circulation auxiliary system; according to a preset hemolysis index component transfer equation and the flow velocity field and shear stress distribution of the mechanical circulation auxiliary system, hemolysis index distribution of the mechanical circulation auxiliary system is obtained, and the preset hemolysis index component transfer equation comprises items used for describing accumulation of blood injuries along with time. The accuracy of predicting the hemolysis index of the mechanical circulation auxiliary system is at least improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of medical devices, and particularly to a method, a system, an electronic device and a storage medium for predicting a hemolysis index. Background Art

[0002] Mechanical circulatory support (MCS) is a life support technology that can provide effective assistance to a patient's circulatory system through a mechanical circulatory support system, correct the patient's hemodynamic disorder state, improve the perfusion of the patient's organ tissues, and increase the patient's survival rate.

[0003] Among them, hemolysis caused by mechanical stress is one of the most important issues to be considered in the design of mechanical circulatory support systems. The hemolysis performance directly determines the success or failure of the entire system design. Therefore, accurately predicting the hemolysis characteristics caused by mechanical stress can shorten the R & D cycle and reduce the experimental cost, which is of great significance for the design and modification of the entire extracorporeal circulatory support system.

[0004] However, at present, the prediction of the hemolysis index of mechanical circulatory support systems is not accurate enough to well guide the design of mechanical circulatory support systems. Summary of the Invention

[0005] The embodiments of the present application provide a method, a system, an electronic device and a storage medium for predicting a hemolysis index, which is at least beneficial to improving the accuracy of predicting the hemolysis index of mechanical circulatory support systems.

[0006] According to some embodiments of the present application, on the one hand, the embodiments of the present application provide a method for predicting a hemolysis index, including: determining the velocity field and shear stress distribution of the mechanical circulatory support system according to the mechanical structure of the mechanical circulatory support system; obtaining the hemolysis index distribution of the mechanical circulatory support system according to a preset hemolysis index component transfer equation and the velocity field and shear stress distribution of the mechanical circulatory support system, wherein the preset hemolysis index component transfer equation includes a term for describing the accumulation of blood damage over time.

[0007] In some embodiments, the determining the velocity field and shear stress distribution of the mechanical circulatory support system according to the mechanical structure of the mechanical circulatory support system includes: obtaining a digital model representing the mechanical structure of the mechanical circulatory support system; solving the fluid control equation corresponding to the mechanical circulatory support system according to the digital model to obtain the velocity field and shear stress distribution of the mechanical circulatory support system.

[0008] In some embodiments, obtaining a digital model representing the mechanical structure of the mechanical circulatory assist system includes: invoking the ANSYS Space Claim module of ANSYS software to process the mechanical structure of the mechanical circulatory assist system to generate a target geometric structure; invoking the ANSYS Fluent Meshing module of ANSYS software to process the target geometric structure to generate the digital model; and according to the digital model, solving the fluid control equation corresponding to the mechanical circulatory assist system includes: invoking the ANSYS Fluent module of ANSYS software to process the digital model according to preset calculation settings to generate and solve the fluid control equation corresponding to the mechanical circulatory assist system.

[0009] In some embodiments, the hemolysis index component transfer equation includes the following expression: where D b is the blood damage index, which is used to reflect the relationship between blood damage and exposure time t in the mechanical circulatory assist system, that is is the velocity vector in the velocity field of the mechanical circulatory assist system, t is time, τ is the equivalent shear stress in the shear stress distribution of the mechanical circulatory assist system, HI is the hemolysis index, and C, α, and β are empirical constants.

[0010] In some embodiments, according to the preset hemolysis index component transfer equation, and the velocity field and shear stress distribution of the mechanical circulatory assist system, obtaining the hemolysis index distribution of the mechanical circulatory assist system includes: writing the hemolysis index component transfer equation as a custom scalar equation into the ANSYS FLUENT module of ANSYS software; invoking the ANSYS FLUENT module of ANSYS software to solve the hemolysis index component transfer equation by using the velocity field and shear stress distribution of the mechanical circulatory assist system to obtain the hemolysis index distribution of the mechanical circulatory assist system.

[0011] In some embodiments, the value range of the empirical constant C is (1.71e-8, 1.89e-08), the value range of the empirical constant α is (0.7268, 0.8033), and the value range of the empirical constant β is (1.891, 2.091).

[0012] In some embodiments, after obtaining the hemolysis index distribution of the mechanical circulatory assist system according to the preset hemolysis index component transfer equation, and the velocity field and shear stress distribution of the mechanical circulatory assist system, the method further includes: determining the flow average value of the hemolysis index at the outlet section of the mechanical circulatory assist system according to the hemolysis index distribution, and the flow average value is used to evaluate the design quality of the mechanical circulatory assist system.

[0013] According to some embodiments of the present application, on the other hand, the present application embodiments also provide a mechanical circulatory assist system, and the design evaluation of the mechanical circulatory assist system utilizes the information obtained by the prediction method of the hemolysis index described in any one of the above embodiments.

[0014] According to some embodiments of the present application, on the other hand, the present application embodiments also provide an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the prediction method of the hemolysis index described in any one of the above embodiments.

[0015] According to some embodiments of the present application, on the other hand, the present application embodiments also provide a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, it implements the prediction method of the hemolysis index described in any one of the above embodiments.

[0016] The technical solutions provided by the embodiments of the present application have at least the following advantages:

[0017] When predicting the hemolysis index of a mechanical circulatory assist system, a term for describing the accumulation of blood damage over time is introduced into the hemolysis index component transfer equation, associating blood damage with time. In this way, when using the hemolysis index component transfer equation and the velocity field and shear stress distribution of the mechanical circulatory assist system determined according to the mechanical structure of the mechanical circulatory assist system to obtain the hemolysis index distribution of the mechanical circulatory assist system, the time variation can also be incorporated into the prediction of the hemolysis index, so that more comprehensive information can be referred to for hemolysis index prediction, which is beneficial to improving the prediction accuracy. Furthermore, not only can the research and development design cycle of the mechanical circulatory assist system be shortened and the research and development cost be reduced, but also a flow channel structure with good hemolysis characteristics can be designed for the mechanical circulatory assist system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are illustrated by way of example in the accompanying drawings, and these exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, and the drawings in the figures do not constitute a proportional limitation.

[0019] Figure 1 is a flowchart of a method for predicting the hemolysis index provided in the embodiments of the present application;

[0020] Figure 2 is another flowchart of a method for predicting the hemolysis index provided in the embodiments of the present application;

[0021] Figure 3 It is a schematic structural diagram of the blood pump provided in the embodiment of the present application;

[0022] Figure 4 It is provided in the embodiment of the present application Figure 3 The sectional view of the digital model of the blood pump shown along the section line F-F;

[0023] Figure 5 It is a schematic comparison diagram of the simulation results of the FLUENT module and the actual experimental results provided in the embodiment of the present application;

[0024] Figure 6 It is the effect diagram of the prediction method of the hemolysis index provided in the embodiment of the present application;

[0025] Figure 7 It is a schematic structural diagram of the electronic device provided in the embodiment of the present application. Detailed implementation manners

[0026] As can be seen from the background art, there is a problem that the prediction of the hemolysis index is not accurate enough in the current design process of the mechanical circulatory assist system.

[0027] After analysis, it is found that the main reason for the above technical problems is that although the hemolysis index of the mechanical circulatory assist system can be obtained by experimental measurement, the experimental measurement period is long and the cost is high. Therefore, currently, computational fluid dynamics (CFD) is usually used to predict and evaluate the hemolysis index of the mechanical circulatory assist system. It realizes the prediction and evaluation of the hemolysis index by establishing a hemolysis index calculation model of the mechanical circulatory assist system based on the hemolysis index, the equivalent shear stress τ, the exposure time t, and a series of empirical constants, and using computational fluid dynamics for solution. Specifically, the expression of the hemolysis index calculation model is as follows:

[0028] H(τ,t) = Cτ α t β (1)

[0029] Among them, H(τ,t) represents the hemolysis volume; τ is the equivalent shear stress, and τ can be calculated through the stress tensor; t is the exposure time, and C, α, and β are empirical constants, such as empirical constants obtained by fitting experimental data.

[0030] In order to couple the above formula (1) into the solution result of computational fluid dynamics, therefore, the exposure time term in formula (1) is linearized to obtain the blood damage D I , that is:

[0031]

[0032] Assume that the derivative of blood damage D distributed along the streamline I with respect to the exposure time t is a constant. At this time, Equation (2) can be simplified into a partial differential equation, that is:

[0033]

[0034] Meanwhile, by expanding the total derivative, the hyperbolic transfer equation of blood damage D I can be derived, that is:

[0035]

[0036] Equation (4) is the single transfer equation describing blood damage, where is the velocity vector in the velocity field of the mechanical circulatory assist system.

[0037] Therefore, the blood damage transfer equation is Equation (4). After obtaining the distribution of the velocity field of the mechanical circulatory assist system,

[0038] solving Equation (4) can obtain the hemolysis index distribution of the mechanical circulatory assist system.

[0039] As can be seen from the above, the current blood damage transfer equation is based on the assumption that the derivative of blood damage D I with respect to the exposure time t is a constant. This can also be seen from the fact that the expression on the right side of the equal sign in Equation (4) is independent of time. However, the derivative of blood damage D I with respect to the exposure time t being a constant is a completely ideal situation. In fact, the hemolytic damage caused by shear stress during the entire flow process of blood cells has an accumulation effect, and the hardening of blood cell nuclei will also change with time. That is, blood damage D I will actually accumulate with the exposure time t. That is to say, the hemolysis index predicted by Equation (4) is obtained by idealizing the actual situation and does not conform to the actual situation. Therefore, it cannot accurately describe the actual hemolysis index of the mechanical circulatory assist system.

[0040] To solve the above technical problems, the embodiments of the present application provide a method, system, electronic device, and storage medium for predicting the hemolysis index. By setting a term including the description of the accumulation of blood damage over time in the hemolysis index component transfer equation, the accumulation of blood damage over time is taken into account during the determination of the hemolysis index distribution, thereby improving the accuracy of predicting the hemolysis index.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will elaborate on each embodiment of this application with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of this application, many technical details are provided to help readers better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can still be implemented.

[0042] The following division of each embodiment is for convenience of description and should not constitute any limitation on the specific implementation of this application. Each embodiment can be combined and cross-referenced with each other on the premise of no contradiction.

[0043] One aspect of the embodiments of this application provides a method for predicting the hemolysis index, which is applied to any electronic device with computing and processing capabilities, such as a server, a computer, etc. In some embodiments, the process of the method for predicting the hemolysis index is as Figure 1 shown and includes the following steps:

[0044] Step 101: Determine the velocity field and shear stress distribution of the mechanical circulatory assist system according to the mechanical structure of the mechanical circulatory assist system.

[0045] Step 102: Obtain the hemolysis index distribution of the mechanical circulatory assist system according to the preset hemolysis index component transfer equation and the velocity field and shear stress distribution of the mechanical circulatory assist system. The preset hemolysis index component transfer equation includes terms for describing the accumulation of blood damage over time.

[0046] In this way, when predicting the hemolysis index of the mechanical circulatory assist system in the above embodiments, a term for describing the accumulation of blood damage over time is introduced into the hemolysis index component transfer equation, associating blood damage with time. Thus, when using the hemolysis index component transfer equation and the velocity field and shear stress distribution of the mechanical circulatory assist system determined according to the mechanical structure of the mechanical circulatory assist system to obtain the hemolysis index distribution of the mechanical circulatory assist system, the change in time can also be incorporated into the prediction of the hemolysis index, enabling more comprehensive information to be considered for hemolysis index prediction, which is beneficial to improving the accuracy of the prediction. Furthermore, not only can the research and development design cycle of the mechanical circulatory assist system be shortened and the research and development cost be reduced, but also a flow channel structure with good hemolysis characteristics can be designed for the mechanical circulatory assist system.

[0047] To facilitate better understanding by those skilled in the art of the Figure 1 embodiments shown below, the following will provide an explanatory description.

[0048] In step 101, the mechanical circulatory assist system can be any system applying mechanical circulatory assist technology, such as a blood pump, an axial flow pump, etc. The velocity field of the mechanical circulatory assist system refers to the velocity field of the internal blood flow when the mechanical circulatory assist system is working, and the shear stress distribution of the mechanical circulatory assist system refers to the shear stress distribution of the internal blood flow when the mechanical circulatory assist system is working.

[0049] It can be understood that some mechanical circulatory assist systems may provide different working conditions, and for different working conditions (also known as "operating conditions", "working modes", etc.), the velocity field and shear stress distribution of the mechanical circulatory assist system may also be different. Therefore, in some examples, according to the mechanical structure of the mechanical circulatory assist system, to determine the velocity field and shear stress distribution of the mechanical circulatory assist system, it can be achieved in the following way: according to the mechanical structure of the mechanical circulatory assist system and the working parameters under different working conditions, determine the velocity field and shear stress distribution of the mechanical circulatory assist system under each working condition. Thus, it is possible to more comprehensively and accurately predict the hemolysis index of the mechanical circulatory assist system. Further, based on the predicted hemolysis index, it is possible to more accurately and comprehensively provide guidance for the design of the mechanical circulatory assist system.

[0050] In some examples, according to the mechanical structure of the mechanical circulatory assist system, to determine the velocity field and shear stress distribution of the mechanical circulatory assist system, it can also be achieved in the following way: obtain a digital model representing the mechanical structure of the mechanical circulatory assist system; according to the digital model, solve the fluid control equation corresponding to the mechanical circulatory assist system to obtain the velocity field and shear stress distribution of the mechanical circulatory assist system.

[0051] In this way, by constructing a digital model of the mechanical circulatory assist system and based on this determining and solving the corresponding fluid control equation to obtain the velocity field and shear stress distribution of the mechanical circulatory assist system, it is possible to digitalize the mechanical structure of the mechanical circulatory assist system through the digital model, thus facilitating the use of software tools to determine and solve the fluid control equation, without relying on manual methods such as analysis and experiments to determine the velocity field and shear stress distribution of the mechanical circulatory assist system, with higher efficiency, more objective and accurate, and lower implementation difficulty.

[0052] Taking the invocation of ANSYS software as an auxiliary tool as an example, at this time, obtaining a digital model representing the mechanical structure of the mechanical circulatory assist system can be achieved through the following methods: Invoke the ANSYS SpaceClaim module of ANSYS software to process the mechanical structure of the mechanical circulatory assist system to generate a target geometric structure; Invoke the ANSYS Fluent Meshing module of ANSYS software to process the target geometric structure to generate the digital model. Correspondingly, according to the digital model, solving the fluid control equations corresponding to the mechanical circulatory assist system can be achieved through the following methods: Invoke the ANSYS Fluent module of ANSYS software, and process the digital model according to the preset calculation settings to generate and solve the fluid control equations corresponding to the mechanical circulatory assist system.

[0053] That is, import the geometric structure of the mechanical circulatory assist system into the ANSYS Space Claim module to process and obtain a geometric structure that meets the requirements for generating a mesh file as the target geometric structure. Then, import the target geometric structure generated by the ANSYS Space Claim module into the ANSYS Fluent Meshing module, and the digital model of the mechanical circulatory assist system will be obtained at the output end. Next, write the relevant calculation settings into the ANSYS Fluent module, so as to run the ANSYS Fluent module, enabling it to determine the corresponding fluid control equations and solve the output results, that is, obtain the velocity field and shear stress distribution of the mechanical circulatory assist system.

[0054] Among them, the preset calculation settings are mainly used to provide constraints for the construction of fluid control equations. For example, for the mechanical circulatory assist system that currently needs to predict the hemolysis index, provide various information such as fluid material properties, steady-state calculation type, fluid model, fluid domain conditions, turbulence model, boundary conditions, mesh interface, reference value setting, setting the solution method, solution control parameters, monitoring parameters, and initial values, so as to be able to generate the corresponding fluid control equations and solve them.

[0055] It should be noted that the mesh file includes the mesh model data of the mechanical circulatory assist system. It can be understood that since the ANSYS Fluent Meshing module of the ANSYS software has certain requirements for the input when generating a digital model, such as the geometric structure cannot be too complex, etc. Therefore, before calling the ANSYS Fluent Meshing module of the ANSYS software, the ANSYS Space Claim module of the ANSYS software is first called for processing to obtain a target geometric structure that meets the input requirements of the ANSYS Fluent Meshing module of the ANSYS software. Of course, when it is determined that the mechanical structure of the mechanical circulatory assist system obtained meets the input requirements of the ANSYS Fluent module of the ANSYS software, there is no need to call the ANSYS Space Claim module of the ANSYS software for processing.

[0056] It should also be noted that the internal processing of the ANSYS software is essentially simulation, so the output results will be affected by the preset calculation settings. Therefore, when reliable reference data can be obtained, such as relevant experimental data or other relevant materials, the velocity field and shear stress distribution of the mechanical circulatory assist system output by the ANSYS software can be verified accordingly, and the calculation settings can be adjusted accordingly according to the verification results until no adjustment is required.

[0057] In step 202, the specific expression of the preset hemolysis index component transfer equation is not limited, and it can be any hemolysis index component transfer equation that includes terms for describing the accumulation of blood damage over time.

[0058] In some examples, the hemolysis index component transfer equation may include the following expression:

[0059]

[0060]

[0061] Among them, D b is the blood damage index, which is used to reflect the relationship between blood damage and exposure time t in the mechanical circulatory assist system, that is, D b = τ α / β ·t, is the velocity vector in the velocity field of the mechanical circulatory assist system, t is the time, τ is the equivalent shear stress in the shear stress distribution of the mechanical circulatory assist system, HI is the hemolysis index, and C, α, and β are empirical constants.

[0062] It should be noted that in this embodiment, the specific values of the empirical constants C, α, and β are not limited, and they can be obtained by fitting according to experiments or can be taken according to experience, etc.

[0063] In some cases, the value range of the empirical constant C is (1.71e - 8, 1.89e - 8), the value range of the empirical constant α is (0.7268, 0.8033), and the value range of the empirical constant β is (1.891, 2.091). For example, the empirical constant C is 1.8e - 8, the empirical constant α is 0.765, and the empirical constant β is 1.991. Thus, when the empirical constants are within the above ranges, the hemolysis situation of the mechanical circulatory assist system reflected by the obtained formulas (5) and (6) is more in line with the actual situation, which is conducive to more accurately predicting the hemolysis index of the mechanical circulatory assist system.

[0064] To facilitate better understanding of the expression of the above hemolysis index component transfer equation by those skilled in the art, the following will explain it.

[0065] First, according to the characteristic that blood damage accumulates over time, a blood damage index D is defined for the continuous accumulation of ruptured red blood cells along the particle trace line over time b , that is:

[0066] D b = τ α / β ·t (7)

[0067] Among them, D b represents the cumulative damage suffered by blood cells under shear stress within a certain time, which can reflect the relationship between blood damage and exposure time t. τ is the equivalent shear stress in the shear stress distribution of the mechanical circulatory assist system, and α and β are empirical constants.

[0068] By taking the derivative of formula (5), the aforementioned formula (5) can be obtained. Correspondingly, according to the time - related characteristics represented by formula (7), the component transfer equation of the hemolysis index (HI) distribution will be expressed as the aforementioned formula (6).

[0069] Obviously, compared with formula (4), the aforementioned formula (6) contains the historical information of red blood cells, takes into account the influence of time, and incorporates the accumulation of blood damage over time in the determination of the hemolysis index distribution, thereby improving the accuracy of predicting the hemolysis index.

[0070] It should be noted that the above formula (7) is only an exemplary description of the term used to describe the accumulation of blood damage over time. In other examples, the term used to describe the accumulation of blood damage over time can also have other forms, such as conducting experiments using existing mechanical circulatory assist systems, and then fitting the specific expression of D b (τ, t) according to the parameters obtained from the experiments to obtain the expression with the minimum error, and then D b(τ, t) The time-related characteristic adaptation reflected in the component transfer equation for adaptively modifying the hemolysis index (HI) distribution will not be elaborated here one by one.

[0071] Taking the invocation of ANSYS software as an auxiliary tool as an example, according to the preset component transfer equation of the hemolysis index, as well as the velocity field and shear stress distribution of the mechanical circulatory assist system, the hemolysis index distribution of the mechanical circulatory assist system can be obtained in the following way: Write the component transfer equation of the hemolysis index as a custom scalar equation into the ANSYS FLUENT module of ANSYS software; Invoke the ANSYS FLUENT module of ANSYS software, and use the velocity field and shear stress distribution of the mechanical circulatory assist system to solve the component transfer equation of the hemolysis index to obtain the hemolysis index distribution of the mechanical circulatory assist system.

[0072] That is, use the custom scalar equation in ANSYS FLUENT to establish the component transfer equations of the blood damage index and the hemolysis index as described above, and then use the FLUENT secondary development platform to define the expressions on the right side of equations (5) and (6) to calculate the hemolysis index distribution of the entire mechanical circulatory assist system based on the velocity field and shear stress distribution of the mechanical circulatory assist system.

[0073] Of course, the foregoing description taking the invocation of ANSYS software as an auxiliary tool as an example is only an exemplary illustration. In other examples, other auxiliary tools can also be used, such as Openfoam, etc., and relevant programming can also be carried out, which will not be elaborated here one by one.

[0074] In some embodiments, the process of the hemolysis index prediction method can also be as Figure 2 shown, including the following steps:

[0075] Step 201, Determine the velocity field and shear stress distribution of the mechanical circulatory assist system according to the mechanical structure of the mechanical circulatory assist system.

[0076] Step 202, According to the preset component transfer equation of the hemolysis index, as well as the velocity field and shear stress distribution of the mechanical circulatory assist system, obtain the hemolysis index distribution of the mechanical circulatory assist system. The preset component transfer equation of the hemolysis index includes terms for describing the accumulation of blood damage over time.

[0077] Step 203, Determine the flow average value of the hemolysis index at the outlet section of the mechanical circulatory assist system according to the hemolysis index distribution. The flow average value is used to evaluate the design quality of the mechanical circulatory assist system.

[0078] In this way, by setting a term for describing the accumulation of blood damage over time in the hemolysis index component transfer equation, the accumulation of blood damage over time is taken into account during the determination of the hemolysis index distribution, thereby improving the accuracy of predicting the hemolysis index. At the same time, the average flow rate can be further determined based on the hemolysis index distribution as the evaluation result of the design quality of the mechanical circulatory assist system, so that it is possible to intuitively determine whether the current design meets the hemolysis performance requirements of the mechanical circulatory assist system.

[0079] It should be noted that Figure 2 in the illustrated embodiment, steps 201 - 202 are substantially the same as Figure 1 steps 101 - 102 in the illustrated embodiment. Figure 2 The difference between the illustrated embodiment and the Figure 1 illustrated embodiment mainly lies in that after determining the hemolysis index distribution of the mechanical circulatory assist system, further applications will be made to the hemolysis index distribution. Therefore, steps 201 - 202 will not be elaborated here one by one.

[0080] To facilitate those skilled in the art to better understand the hemolysis index prediction method and its effects provided by the above embodiments, the following will take the mechanical circulatory assist system as Figure 3 and Figure 4 the illustrated benchmark centrifugal blood pump as an example for illustration. Among them, Figure 3 is the combined structural schematic diagram of the benchmark centrifugal blood pump. As can be seen from Figure 3 , the benchmark centrifugal blood pump is composed of three parts: an inlet section A, an impeller rotation area B, and a volute section C.

[0081] First, import the mechanical structure data of the Figure 3 illustrated benchmark centrifugal blood pump into the ANSYS Space Claim module, and import the geometric structure output by the ANSYS SpaceClaim module into the ANSYS Fluent Meshing module to generate a mesh inside. The generated mesh file, where the digital model indicated by the mesh file along the Figure 3 illustrated section line F - F has a sectional view as Figure 4 shown.

[0082] Then, import the mesh file generated by the ANSYS Fluent Meshing module into the Fluent module, and according to the operation configuration process of the Fluent module, set the preset calculation configuration into the Fluent module. Among them, the turbulence model uses the SST model, and the inlet and outlet boundaries are the flow inlet and pressure outlet boundaries respectively.

[0083] Among them, considering the various working conditions of the reference centrifugal blood pump, simulations are carried out for different working conditions. For example, the relevant parameters of working condition 1 (Case1: flow rate Q = 2.5 L / min; rotational speed N = 2500 rpm), working condition 4 (Case4: flow rate Q = 6 L / min; rotational speed N = 2500 rpm), and working condition 5 (Case5: flow rate Q = 6 L / min; rotational speed N = 3500 rpm) are used as the corresponding calculation configurations and set into different simulation scenarios of the Fluent module. The obtained simulation data are the velocity field and shear stress distribution of the reference centrifugal blood pump under the above three working conditions.

[0084] Moreover, in order to verify the effectiveness of the numerical simulation, the output results of the Fluent module are compared with the experimental measurement results. As Figure 5 shown, the head of the blood pump under the three working conditions (Case1, Case4, Case4) output by the Fluent module through simulation is basically consistent with the head of the blood pump obtained experimentally, thus generally verifying the effectiveness, rationality, and accuracy of the method for determining the velocity field and shear stress distribution of the mechanical circulatory assist system in the embodiments of the present application. Among them, Figure 5 in the bar chart shown, the abscissa is each working condition of different working conditions, the ordinate is the head of the blood pump, and the unit is (millimeters of mercury, mmHg). Result 1 corresponds to the result obtained experimentally, and result 2 represents the result output by the Fluent module through simulation. The black vertical line on result 1 is the error line of the experimental result.

[0085] Next, an association relationship between the hemolysis index, blood damage index, and shear stress is established, and scalar equations for the blood damage index and hemolysis index are defined. Specifically, the aforementioned formulas (5) and (6) are implemented in the user-defined scalar equation in the Fluent module, and user-defined functions are used to define the expressions on the right side of the equal sign in the aforementioned formulas (5) and (6). In this way, after the Fluent module uses the previously obtained velocity field and shear stress distribution of the mechanical circulatory assist system as input, it will be able to calculate and solve the hemolysis index distribution of the mechanical circulatory assist system. At this time, the hemolysis index distribution of the mechanical circulatory assist system at the average flow rate on the outlet section is as Figure 6 shown. Among them, Figure 6 in the bar chart shown, the abscissa is each working condition of different working conditions, and the ordinate is the hemolysis index. From Figure 6 it can be seen the changing trend of the hemolysis index of the mechanical circulatory assist system, thus providing a basis for the design or modification of the reference centrifugal blood pump as Figure 4 shown.

[0086] The step division of the above various methods is only for clear description. When implemented, they can be combined into one step or some steps can be split into multiple steps. As long as the same logical relationship is included, it is within the protection scope of this patent. Making insignificant modifications to the algorithm or process or introducing insignificant designs without changing the core design of the algorithm and process are all within the protection scope of this patent.

[0087] Another aspect of the embodiments of the present application further provides a mechanical circulatory assist system. The design evaluation of the mechanical circulatory assist system utilizes the information obtained by the prediction method of the hemolysis index described in any one of the above embodiments.

[0088] It should be noted that the structure of the mechanical circulatory assist system is not specifically limited in this embodiment. According to different requirements and the information obtained by the prediction method of the hemolysis index described in any one of the above embodiments, specific designs are carried out.

[0089] It is not difficult to find that this embodiment is a system embodiment corresponding to the method embodiment, and this embodiment can be implemented in cooperation with the method embodiment. The relevant technical details mentioned in the method embodiment are still valid in this embodiment. To avoid repetition, they are not elaborated here. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the method embodiment.

[0090] It is worth mentioning that each module involved in this embodiment is a logical module. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or can be implemented by a combination of multiple physical units. In addition, to highlight the innovative part of the present application, units not closely related to solving the technical problems proposed in the present application are not introduced in this embodiment, but this does not mean that there are no other units in this embodiment.

[0091] Another aspect of the embodiments of the present application further provides an electronic device, as Figure 7 shown, including: at least one processor 701; and a memory 702 communicatively connected to the at least one processor 701; wherein, the memory 702 stores instructions executable by the at least one processor 701, and the instructions are executed by the at least one processor 701 to enable the at least one processor 701 to execute the prediction method of the hemolysis index described in any one of the above method embodiments.

[0092] Among them, the memory 702 and the processor 701 are connected in a bus manner. The bus can include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors 701 and the memory 702 together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, etc. These are well known in the art, so they will not be further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single component or multiple components, such as multiple receivers and transmitters, and provides a unit for communicating with various other devices over the transmission medium. The data processed by the processor 701 is transmitted over the wireless medium through the antenna. Further, the antenna also receives data and transmits the data to the processor 701.

[0093] The processor 701 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interface, voltage regulation, power management, and other control functions. The memory 702 can be used to store the data used by the processor 701 when performing operations.

[0094] Another aspect of the embodiments of the present application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the prediction method of the hemolysis index described in any of the above method embodiments.

[0095] That is, those skilled in the art can understand that all or part of the steps in implementing the methods of the above embodiments can be completed by instructing relevant hardware through a program. The program is stored in a storage medium, including several instructions for causing a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0096] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present application, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. A method for predicting hemolysis index, characterized in that, The method includes: Determining the velocity field and shear stress distribution of the mechanical circulatory assist system according to the mechanical structure of the mechanical circulatory assist system; Obtaining the hemolysis index distribution of the mechanical circulatory assist system according to a preset hemolysis index component transfer equation and the velocity field and shear stress distribution of the mechanical circulatory assist system, wherein the preset hemolysis index component transfer equation includes a term for describing the accumulation of blood damage over time.

2. The prediction method of hemolysis index according to claim 1, characterized in that, The determining the velocity field and shear stress distribution of the mechanical circulatory assist system according to the mechanical structure of the mechanical circulatory assist system includes: Obtaining a digital model characterizing the mechanical structure of the mechanical circulatory assist system; Solving the fluid control equation corresponding to the mechanical circulatory assist system according to the digital model to obtain the velocity field and shear stress distribution of the mechanical circulatory assist system.

3. The prediction method of hemolysis index according to claim 2, wherein The obtaining a digital model characterizing the mechanical structure of the mechanical circulatory assist system includes: Invoking the ANSYS SpaceClaim module of ANSYS software to process the mechanical structure of the mechanical circulatory assist system to generate a target geometric structure; Invoking the ANSYS Fluent Meshing module of ANSYS software to process the target geometric structure to generate the digital model; The solving the fluid control equation corresponding to the mechanical circulatory assist system according to the digital model includes: Invoking the ANSYS Fluent module of ANSYS software to process the digital model according to preset calculation settings to generate and solve the fluid control equation corresponding to the mechanical circulatory assist system.

4. The prediction method of hemolysis index according to any one of claims 1 to 3, characterized in that, The hemolysis index component transfer equation includes the following expression: Among them, D b is the blood injury index, which is used to reflect the relationship between blood injury and exposure time t in the mechanical circulatory assist system, that is, D b = τ α / β ·t, is the velocity vector in the velocity field of the mechanical circulatory assist system, t is the time, τ is the equivalent shear stress in the shear stress distribution of the mechanical circulatory assist system, HI is the hemolysis index, and C, α, and β are empirical constants.

5. The prediction method of hemolysis index according to claim 4, characterized in that The value range of the empirical constant C is (1.71e-8, 1.89e-8), the value range of the empirical constant α is (0.7268, 0.8033), and the value range of the empirical constant β is (1.891, 2.091).

6. The prediction method of hemolysis index according to any one of claims 1 to 3, characterized in that, The obtaining the hemolysis index distribution of the mechanical circulatory assist system according to a preset hemolysis index component transfer equation and the velocity field and shear stress distribution of the mechanical circulatory assist system includes: Writing the hemolysis index component transfer equation as a custom scalar equation into the ANSYS FLUENT module of ANSYS software; Invoking the ANSYS FLUENT module of ANSYS software to solve the hemolysis index component transfer equation by using the velocity field and shear stress distribution of the mechanical circulatory assist system to obtain the hemolysis index distribution of the mechanical circulatory assist system.

7. The prediction method of hemolysis index according to any one of claims 1 to 3, characterized in that After the obtaining the hemolysis index distribution of the mechanical circulatory assist system according to a preset hemolysis index component transfer equation and the velocity field and shear stress distribution of the mechanical circulatory assist system, the method further includes: Determining the flow average value of the hemolysis index at the outlet section of the mechanical circulatory assist system according to the hemolysis index distribution, and the flow average value is used to evaluate the design quality of the mechanical circulatory assist system.

8. A mechanical circulatory assist system, characterized in that, The design evaluation of the mechanical circulatory assist system utilizes the information obtained by the hemolysis index prediction method according to any one of claims 1 to 7.

9. An electronic device, characterized in that, Comprising: At least one processor; And, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor is enabled to execute the method for predicting hemolysis index according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method for predicting hemolysis index according to any one of claims 1 to 7.

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