A device and apparatus for quantitatively evaluating vascular wall function

Abstract

The present application discloses a device and equipment for quantitatively evaluating vascular wall function, and relates to the field of data analysis technology. The device specifically uses multi-phase imaging data of arterial blood vessels to establish a multi-dimensional dynamic arterial blood vessel model corresponding to the blood vessel expansion stage, and determines the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor based on the model; further fits the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor to obtain a stress-strain curve; and defines the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance according to the stress-strain curve. Since the vascular wall elastic potential energy reserve coefficient describes the elastic potential energy stored in the arterial blood vessel expansion stage, and the vascular wall strain resistance reflects the difficulty of the vascular wall in storing elastic potential energy through deformation, based on the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance, combined with conventional clinical information, it is possible to make a personalized quantitative evaluation of the vascular function of the target to be measured, thereby improving the credibility of the vascular wall evaluation results.

Description

Technical Field

[0001] The present application relates to the field of data analysis technology, and in particular to a device and equipment for quantitatively evaluating vascular wall function. Background Art

[0002] The vascular wall is a structure that maintains the shape and elasticity of the blood vessels. It can withstand the pressure of blood flow and prevent blood leakage, and is involved in regulating blood pressure and blood flow. The evaluation of the vascular wall can provide detailed information on the vascular structure, evaluate vascular lesions, guide clinical treatment, monitor disease progression and treatment effects, and achieve personalized medicine. It is of great value in the diagnosis, treatment and monitoring of cardiovascular diseases.

[0003] At present, the function of the vascular wall is mainly evaluated by analyzing the stiffness of the vascular wall. However, since each person's vascular wall stiffness and blood pressure are individual differences, a simple stiffness analysis cannot fully reflect the evaluation of the vascular wall function and is not representative.

[0004] In view of the above problems, how to solve the current analysis of the stiffness of the vascular wall, which cannot fully reflect the functional evaluation of the vascular wall due to individual differences and is not representative, is an urgent problem to be solved by technicians in this field. Summary of the invention

[0005] The purpose of this application is to provide a device and equipment for quantitatively evaluating the function of the vascular wall to solve the problem that the current analysis of the stiffness of the vascular wall cannot fully reflect the functional evaluation of the vascular wall due to individual differences and is not representative.

[0006] In order to solve the above technical problems, the present application provides a device for quantitatively evaluating vascular wall function, comprising:

[0007] A multi-dimensional dynamic arterial blood vessel model building module, used to collect multi-phase arterial image data based on the target site, and to build a multi-dimensional dynamic arterial blood vessel model corresponding to the blood vessel expansion stage according to the arterial image data;

[0008] A strain stress tensor determination module, used for determining an arterial blood vessel strain tensor and an arterial blood vessel wall stress tensor according to the multi-dimensional dynamic arterial blood vessel model;

[0009] A curve fitting module, used for fitting the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor to obtain a stress-strain curve;

[0010] An evaluation parameter definition module, used to define a vascular wall elastic potential energy reserve coefficient and a vascular wall strain resistance according to the stress-strain curve;

[0011] The vascular wall function evaluation module is used to determine the vascular wall function evaluation result of the target part according to the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance.

[0012] On the one hand, the multi-dimensional dynamic arterial blood vessel model building module includes:

[0013] An arterial blood vessel model building module, used to build a multi-phase arterial blood vessel model according to the arterial image data;

[0014] An expansion phase determination module, used to determine the phase corresponding to the blood vessel expansion phase according to the arterial blood vessel model;

[0015] a displacement field information determination module, configured to determine the displacement field information according to the time phase corresponding to the blood vessel expansion stage and the arterial image data; wherein the displacement field information represents the displacement of the arterial blood vessel model at each time phase of the blood vessel expansion stage relative to the arterial blood vessel model at a reference time phase; the reference time phase is the blood vessel expansion start time phase or the blood vessel expansion end time phase;

[0016] The superposition module is used to superimpose the arterial blood vessel model and the displacement field information to obtain the multi-dimensional dynamic arterial blood vessel model.

[0017] On the other hand, the strain stress tensor determination module includes:

[0018] A first coordinate determination module, used to obtain the starting coordinates of the arterial blood vessel model at the starting phase of blood vessel expansion;

[0019] A displacement field description function determination module, used to determine a displacement field description function according to the displacement field information; wherein the displacement field description function is a function of the coordinates of the arterial blood vessel model and time;

[0020] A second coordinate determination module, used to determine the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage according to the starting coordinates and the displacement field description function;

[0021] The arterial blood vessel strain tensor determination module is used to determine the arterial blood vessel strain tensor according to the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage.

[0022] On the other hand, the arterial vascular strain tensor determination module includes:

[0023] A deformation gradient determination module, used to determine the deformation gradient according to the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage;

[0024] The strain tensor calculation module is used to select a strain tensor calculation formula and determine the arterial blood vessel strain tensor according to the strain tensor calculation formula and the deformation gradient.

[0025] On the other hand, the strain stress tensor determination module includes:

[0026] A blood pressure parameter acquisition module is used to obtain the blood pressure parameters corresponding to each time during the blood vessel expansion stage;

[0027] The arterial blood vessel wall stress tensor determination module is used to determine the arterial blood vessel wall stress tensor according to the multi-dimensional dynamic arterial blood vessel model and the blood pressure parameter.

[0028] On the other hand, the arterial blood vessel wall stress tensor determination module includes:

[0029] The equilibrium equation establishment module is used to establish a quasi-static equilibrium equation; wherein the quasi-static equilibrium equation is specifically as follows:

[0030] ;

[0031] in, is the current geometric position of the multi-dimensional dynamic arterial vascular model, is the Cauchy stress, is the mass force, is the predefined surface load, i.e., the blood pressure parameter; , is the external normal vector of the load application boundary, is the boundary to which the surface load is applied, is the deformation displacement;

[0032] The Cauchy stress solving module is used to solve the Cauchy stress in the quasi-static equilibrium equation according to the multi-dimensional dynamic arterial blood vessel model and the blood pressure parameter to determine the arterial blood vessel wall stress tensor.

[0033] On the other hand, the curve fitting module comprises:

[0034] The fitting execution module is used to determine a target fitting formula, and fit the arterial vascular strain tensor and the arterial vascular wall stress tensor based on the target fitting formula to obtain the stress-strain curve; the target fitting formula is as follows:

[0035] ;

[0036] in, is the arterial vascular strain tensor, is the arterial wall stress tensor, is the fitting parameter.

[0037] On the other hand, the evaluation parameter definition module includes:

[0038] A strain peak value acquisition module, used to obtain the strain peak value during the blood vessel expansion stage;

[0039] A parameter definition submodule, used to define the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance according to the stress-strain curve and the strain peak value;

[0040] The definition of the vascular wall elastic potential energy reserve coefficient is as follows:

[0041] ;

[0042] in, is the elastic potential energy reserve coefficient of the vascular wall, is the peak strain value, is the arterial vascular strain tensor, is the arterial blood vessel wall stress tensor;

[0043] The definition of the vascular wall strain resistance is as follows:

[0044] ;

[0045] in, is the vascular wall strain resistance, is the peak strain value, is the arterial vascular strain tensor, is the arterial wall stress tensor.

[0046] On the other hand, the vascular wall function assessment module comprises:

[0047] The evaluation and judgment module is used to judge whether the elastic potential energy reserve coefficient of the blood vessel wall is not less than a first threshold value, and the blood vessel wall strain resistance is not greater than a second threshold value; if so, it is confirmed that the blood vessel wall function of the target part meets the preset requirements; if not, it is confirmed that the blood vessel wall function of the target part does not meet the preset requirements.

[0048] In order to solve the above technical problems, the present application also provides a vascular wall function quantitative evaluation device, including the above vascular wall function quantitative evaluation device.

[0049] The device for quantitatively evaluating the function of the vascular wall provided in the present application includes a multi-dimensional dynamic arterial model building module, a strain stress tensor determination module, a curve fitting module, an evaluation parameter definition module, and a vascular wall function evaluation module; it can collect multi-phase arterial imaging data based on the target site, and establish a multi-dimensional dynamic arterial model corresponding to the vascular expansion stage according to the arterial imaging data; determine the arterial strain tensor and the arterial wall stress tensor according to the multi-dimensional dynamic arterial model; fit the arterial strain tensor and the arterial wall stress tensor to obtain a stress-strain curve; define the elastic potential energy reserve coefficient and the vascular wall strain resistance according to the stress-strain curve; determine the vascular wall function evaluation result of the target site according to the elastic potential energy reserve coefficient and the vascular wall strain resistance. It can be seen from this that the present scheme provides a device for evaluating the function of the arterial vessel based on the multi-phase imaging data of the arterial vessel through non-invasive in vivo biomechanical analysis. Specifically, a multi-dimensional dynamic arterial model corresponding to the vascular expansion stage is established using multi-phase image data of arterial vessels, and the arterial strain tensor and arterial wall stress tensor are determined based on the model; the arterial strain tensor and arterial wall stress tensor are further fitted to obtain the stress-strain curve; the elastic potential energy reserve coefficient of the vascular wall and the vascular wall strain resistance are defined according to the stress-strain curve. Since the elastic potential energy reserve coefficient of the vascular wall describes the elastic potential energy stored in the arterial expansion stage, and the vascular wall strain resistance reflects the difficulty of the vascular wall in storing elastic potential energy through deformation, based on the vascular wall elastic potential energy reserve coefficient and vascular wall strain resistance, combined with conventional clinical information, a personalized quantitative evaluation of the vascular function of the target to be measured can be made, which improves the credibility of the vascular wall assessment results.

[0050] In addition, the present application also provides a vascular wall function quantitative evaluation device, which includes the above-mentioned vascular wall function quantitative evaluation device and has the same effect as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0052] Figure 1 A schematic diagram of a device for quantitatively evaluating vascular wall function provided in an embodiment of the present application;

[0053] Figure 2 A schematic diagram of a multi-dimensional dynamic arterial blood vessel model establishment module provided in an embodiment of the present application;

[0054] Figure 3A schematic diagram of a blood vessel volume change curve during a cardiac cycle provided in an embodiment of the present application;

[0055] Figure 4 A schematic diagram of a strain stress tensor determination module provided in an embodiment of the present application;

[0056] Figure 5 A schematic diagram of a fitted stress-strain curve of the expansion phase provided in an embodiment of the present application;

[0057] Figure 6 A schematic diagram of an evaluation parameter definition module provided in an embodiment of the present application;

[0058] Figure 7 A schematic diagram of a device for quantitatively evaluating vascular wall function provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0060] The core of this application is to provide a device and equipment for quantitatively evaluating the function of the vascular wall to solve the problem that the current analysis of the stiffness of the vascular wall cannot fully reflect the functional evaluation of the vascular wall due to individual differences and is not representative.

[0061] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0062] Figure 1 This is a schematic diagram of a device for quantitatively evaluating vascular wall function provided in an embodiment of the present application. Figure 1 As shown, the device comprises:

[0063] The multi-dimensional dynamic arterial blood vessel model building module 10 is used to collect multi-phase arterial image data based on the target site, and to build a multi-dimensional dynamic arterial blood vessel model corresponding to the blood vessel expansion stage according to the arterial image data.

[0064] The strain stress tensor determination module 11 is used to determine the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor according to the multi-dimensional dynamic arterial blood vessel model.

[0065] The curve fitting module 12 is used to fit the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor to obtain a stress-strain curve.

[0066] The evaluation parameter definition module 13 is used to define the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance according to the stress-strain curve.

[0067] The vascular wall function evaluation module 14 is used to determine the vascular wall function evaluation result of the target part according to the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance.

[0068] In order to achieve quantitative evaluation of vascular wall function, it is first necessary to establish a multidimensional dynamic arterial vascular model through a multidimensional dynamic arterial vascular model establishment module. Specifically, multi-phase arterial image data is collected based on the target site. It can be understood that multi-phase arterial image data of the target site of the target to be measured can be collected specifically through Computed Tomography Angiography (CTA), Magnetic Resonance Imaging (MRI) or Ultrasound Imaging. A multidimensional dynamic arterial vascular model corresponding to the vascular expansion stage is further established based on the arterial image data. It should be noted that the vascular expansion stage refers to the phenomenon that the blood vessel expands and widens for some reason. This stage may be caused by a variety of factors, including non-disease factors and disease factors. In this embodiment, the specific method for the multidimensional dynamic arterial vascular model establishment module to establish a multidimensional dynamic arterial vascular model corresponding to the vascular expansion stage based on the arterial image data is not limited, and it depends on the specific implementation situation.

[0069] After obtaining the multi-dimensional dynamic arterial model, the arterial strain tensor and the arterial wall stress tensor are determined by the strain-stress tensor determination module. It should be noted that the arterial strain tensor describes the changes in the shape and size of the arterial blood vessels when they are subjected to external or internal forces, including radial strain, circumferential strain and axial strain; by measuring these strains, the deformation of the arterial blood vessels in different directions can be understood, thereby evaluating the elasticity and compliance of the blood vessels. The arterial wall stress tensor describes the stress distribution generated inside the blood vessel wall when it is subjected to internal pressure and other external forces, including radial stress, circumferential stress and axial stress; by measuring these stresses, the force of the blood vessel wall in different directions can be understood, thereby evaluating the strength and stability of the blood vessel wall. In this embodiment, the specific method for determining the arterial strain tensor and the arterial wall stress tensor by the strain-stress tensor determination module is not limited, and it depends on the specific implementation situation.

[0070] Furthermore, the curve fitting module is used to fit the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor to obtain a stress-strain curve, so that the evaluation parameter definition module defines the blood vessel wall elastic potential energy reserve coefficient (Peri) and the blood vessel wall strain resistance (Rs) according to the stress-strain curve. In this embodiment, there is no restriction on the fitting method of the stress-strain curve, which depends on the specific implementation situation.

[0071] It should be noted that blood vessels, especially the aorta, as important functional organs for blood transportation, must quickly expand the blood vessel wall in a short time when the heart pumps out blood pressure to maintain normal blood transportation, so as to store the pumped blood pressure. Subsequently, after the aortic valve closes, the elastic potential energy stored in the expansion of the blood vessel wall is gradually released, thereby ensuring that the blood has sufficient pressure to complete the transportation from the aorta to the branch arteries and extremities during diastole. This scheme well describes this functional characteristic of the blood vessel and gives a quantitative evaluation through the elastic potential energy reserve coefficient of the blood vessel wall defined by the evaluation parameter definition module. The elastic potential energy reserve coefficient of the blood vessel wall describes how much elastic potential energy is stored in the aorta during the expansion stage to meet the blood transportation function during diastole. Combined with the conventional clinical information of the target to be measured, a personalized quantitative evaluation of the vascular function of the target to be measured can be made. Another parameter defined by the evaluation parameter definition module, the vascular wall strain resistance, reflects the difficulty of the vascular wall in storing elastic potential energy through deformation. Therefore, under the same vascular wall elastic potential energy reserve coefficient, the smaller the vascular wall strain resistance, the better the vascular wall function. In summary, this scheme can determine the vascular wall function evaluation results of the target site according to the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance, make a better personalized quantitative evaluation of the vascular function of the target to be measured, and improve the credibility of the vascular wall evaluation results.

[0072] It should be noted that in this embodiment, there is no restriction on the specific manner in which the evaluation parameter definition module defines the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance, and there is no restriction on the specific manner in which the vascular wall function evaluation module determines the vascular wall function evaluation results of the target site, which depends on the specific implementation situation.

[0073] In this embodiment, a device is provided for evaluating arterial vascular function through non-invasive in vivo biomechanical analysis based on multi-phase imaging data of arterial blood vessels. Specifically, a multi-dimensional dynamic arterial vascular model corresponding to the vascular expansion stage is established using the multi-phase imaging data of arterial blood vessels, and the arterial vascular strain tensor and the arterial vascular wall stress tensor are determined based on the model; the arterial vascular strain tensor and the arterial vascular wall stress tensor are further fitted to obtain a stress-strain curve; and the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance are defined according to the stress-strain curve. Since the vascular wall elastic potential energy reserve coefficient describes the elastic potential energy stored in the arterial blood vessel expansion stage, and the vascular wall strain resistance reflects the difficulty of the vascular wall in storing elastic potential energy through deformation, based on the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance, combined with conventional clinical information, a personalized quantitative evaluation of the vascular function of the target to be measured can be made better, thereby improving the credibility of the vascular wall evaluation results.

[0074] Figure 2 A schematic diagram of a multi-dimensional dynamic arterial blood vessel model building module provided in an embodiment of the present application. Based on the above embodiments, in some embodiments, such as Figure 2 As shown, the multi-dimensional dynamic arterial blood vessel model building module 10 includes:

[0075] The arterial blood vessel model building module 101 is used to build a multi-phase arterial blood vessel model according to arterial image data.

[0076] The expansion phase determination module 102 is used to determine the phase corresponding to the blood vessel expansion phase according to the arterial blood vessel model.

[0077] The displacement field information determination module 103 is used to determine the displacement field information according to the time phase corresponding to the blood vessel expansion stage and the arterial image data; wherein the displacement field information represents the displacement of the arterial blood vessel model at each time phase of the blood vessel expansion stage relative to the arterial blood vessel model at a reference time phase; the reference time phase is the starting time phase of the blood vessel expansion or the ending time phase of the blood vessel expansion.

[0078] The superposition module 104 is used to superimpose the arterial blood vessel model and the displacement field information to obtain a multi-dimensional dynamic arterial blood vessel model.

[0079] In order to establish a multi-dimensional dynamic arterial blood vessel model, the arterial blood vessel model establishment module establishes a multi-phase arterial blood vessel model according to the arterial image data, and the expansion phase determination module further determines the phase corresponding to the blood vessel expansion phase according to the arterial blood vessel model.

[0080] Figure 3 This is a schematic diagram of a blood vessel volume change curve during a cardiac cycle provided by an embodiment of the present application. Figure 3As shown, the phases of the expansion stage from the beginning phase (Beginning) to the peak phase (Peak) can be determined according to the volume transformation curve.

[0081] Furthermore, the displacement field information determination module determines the displacement field information according to the phase corresponding to the blood vessel expansion stage and the arterial image data. It should be noted that the displacement field information represents the displacement of the arterial vascular model at each phase of the blood vessel expansion stage relative to the arterial vascular model at the reference phase. It should be noted that the reference phase can be the beginning phase of blood vessel expansion (Beginning) or the end phase of blood vessel expansion (Peak), which is not limited in this embodiment and depends on the specific implementation situation. Finally, the superposition module superimposes the arterial vascular model and the displacement field information to obtain a multidimensional dynamic arterial vascular model corresponding to the blood vessel expansion stage. In this way, the construction of a multidimensional dynamic arterial vascular model is achieved.

[0082] Figure 4 A schematic diagram of a strain stress tensor determination module provided in an embodiment of the present application. Based on the above embodiments, in some embodiments, such as Figure 4 As shown, the strain stress tensor determination module 11 includes:

[0083] The first coordinate determination module 111 is used to obtain the starting coordinates of the arterial blood vessel model at the starting phase of blood vessel expansion.

[0084] The displacement field description function determination module 112 is used to determine the displacement field description function according to the displacement field information; wherein the displacement field description function is a function of the coordinates of the arterial blood vessel model and time.

[0085] The second coordinate determination module 113 is used to determine the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage according to the initial coordinates and the displacement field description function.

[0086] The arterial blood vessel strain tensor determination module 114 is used to determine the arterial blood vessel strain tensor according to the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage.

[0087] In order to determine the arterial blood vessel strain tensor, in this embodiment, the first coordinate determination module is used to obtain the starting coordinates of the arterial blood vessel model at the start phase of blood vessel expansion. At the same time, the displacement field description function determination module is used to determine the displacement field description function according to the displacement field information. ; It can be understood that the displacement field description function is a function of the coordinates of the arterial blood vessel model and time.

[0088] The second coordinate determination module is further configured based on the starting coordinates and the displacement field description function Determine the coordinates of the multi-dimensional dynamic arterial vascular model during the vascular expansion phase as follows:

[0089] ;

[0090] in, Coordinates of the multidimensional dynamic arterial vascular model during the vascular expansion phase.

[0091] Finally, the arterial blood vessel strain tensor determination module determines the arterial blood vessel strain tensor according to the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage.

[0092] It should be noted that the specific determination process of the arterial vascular strain tensor is not limited in this embodiment and depends on the specific implementation situation. For example, in some embodiments, the arterial vascular strain tensor determination module 114 includes:

[0093] A deformation gradient determination module 1141, for determining a deformation gradient according to coordinates of a multi-dimensional dynamic arterial blood vessel model in a blood vessel expansion phase;

[0094] The strain tensor calculation module 1142 is used to select a strain tensor calculation formula and determine the arterial blood vessel strain tensor according to the strain tensor calculation formula and the deformation gradient.

[0095] Specifically, firstly, the deformation gradient is determined by the deformation gradient determination module according to the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage, as follows:

[0096] ;

[0097] in, is the deformation gradient.

[0098] The strain tensor calculation module further selects a strain tensor calculation formula, and determines the arterial blood vessel strain tensor according to the strain tensor calculation formula and the deformation gradient. For example, the Cauchy-Green strain tensor calculation formula and the Green-Lagrange strain tensor calculation formula can be selected, and the calculation results of both can be used as the final arterial blood vessel strain tensor, as follows:

[0099] ;

[0100] in, is the Cauchy-Green strain tensor.

[0101] ;

[0102] in, is the Green-Lagrange strain tensor, is the unit tensor.

[0103] Based on the above embodiments, in some embodiments, such as Figure 4 As shown, the strain stress tensor determination module 11 includes:

[0104] The blood pressure parameter acquisition module 115 is used to acquire the blood pressure parameters corresponding to each time in the blood vessel expansion stage;

[0105] The arterial wall stress tensor determination module 116 is used to determine the arterial wall stress tensor according to the multi-dimensional dynamic arterial model and blood pressure parameters.

[0106] In order to determine the arterial wall stress tensor, in the present embodiment, the blood pressure parameters corresponding to each time in the blood vessel expansion stage are obtained by the blood pressure parameter acquisition module, and the arterial wall stress tensor is determined by the arterial wall stress tensor determination module according to the multi-dimensional dynamic arterial model and the blood pressure parameters.

[0107] It should be noted that the present embodiment does not limit the method for determining the arterial wall stress tensor. For example, the inverse finite element technique may be used to complete the analysis of the vascular wall stress. Specifically, in some embodiments, the arterial wall stress tensor determination module 116 includes:

[0108] The equilibrium equation establishing module 1161 is used to establish a quasi-static equilibrium equation;

[0109] The Cauchy stress solving module 1162 is used to solve the Cauchy stress in the quasi-static equilibrium equation according to the multi-dimensional dynamic arterial blood vessel model and the blood pressure parameters to determine the arterial blood vessel wall stress tensor.

[0110] Specifically, we first need to establish a quasi-static equilibrium equation that describes the equilibrium state of the blood vessel wall under the action of force through the equilibrium equation establishment module. According to the equilibrium principle in continuous medium mechanics, we can get the stress and external forces For unit area The sum of the fluxes is equal to the internal force For volume The quasi-static equilibrium equation is as follows:

[0111] ;

[0112] in, is the current geometric position of the multidimensional dynamic arterial model, is the Cauchy stress, is the mass force, is the predefined surface load, i.e., the blood pressure parameter; , is the external normal vector of the load application boundary, is the boundary to which the surface load is applied, is the deformation displacement.

[0113] The Cauchy stress solver module further solves the Cauchy stress in the quasi-static equilibrium equation based on the multi-dimensional dynamic arterial model and blood pressure parameters to determine the arterial wall stress tensor. Specifically, in order to solve the Cauchy stress, it is necessary to know the position and deformation of the vascular wall in the initial state. Therefore, it is necessary to calculate the current vascular position, that is, the coordinates of the multi-dimensional dynamic arterial model in the vascular expansion stage. , reversely deduce the blood vessel position in the initial zero load state, that is, the starting coordinates of the arterial blood vessel model at the beginning of blood vessel expansion This requires transforming the forward kinematic equation Convert to inverse kinematics equations The deformation displacement solved at this time is is the reverse displacement .

[0114] In order to describe the deformation of the blood vessel wall, it is also necessary to calculate the reverse deformation gradient. The reverse deformation gradient can be expressed as:

[0115] ;

[0116] in, is the reverse deformation gradient, is the deformation gradient.

[0117] Furthermore, in order to solve the Cauchy stress, it is also necessary to know the material properties of the blood vessel wall. Select a suitable material model for solving the equilibrium equation. Here, a hyperelastic material model suitable for the mechanical properties of biomaterials is taken as an example, and its energy equation is:

[0118] ;

[0119] in, , , is the material coefficient. The first Piola-Kirchhoff stress tensor can be expressed as:

[0120] ;

[0121] in, is the first Piola-Kirchhoff stress tensor.

[0122] Finally, according to the stress relationship, the first Piola-Kirchhoff stress tensor can be converted to Cauchy stress. At this time, the Cauchy stress can be expressed as:

[0123] ;

[0124] in, .at this time, and Both are expressed as The function of About The deformation gradient, displacement is Finally, the above equilibrium equation can be simplified to function, and by solving this equation we determine . The coordinates of the multidimensional dynamic arterial model during the vessel expansion phase Known, the initial stress-free blood vessel position is . Finally, the Cauchy stress can be determined as follows:

[0125] ;

[0126] in, is the inverse deformation tensor, , is the second-order identity tensor.

[0127] In summary, the determination of the stress tensor of the arterial wall is achieved.

[0128] Figure 5 A schematic diagram of a stress-strain curve of the expansion phase provided by an embodiment of the present application. Based on the above embodiment, in some embodiments, the curve fitting module 12 includes:

[0129] The fitting execution module 121 is used to determine a target fitting formula, and fit the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor based on the target fitting formula to obtain a stress-strain curve.

[0130] In the specific implementation, it is necessary to select a biological hyperelastic material model suitable for describing the mechanical properties of blood vessels to fit the stress and strain, so as to obtain Figure 5 The stress-strain curve shown. Specifically, the target fitting formula is as follows:

[0131] ;

[0132] in, is the equivalent Green-Lagrange strain tensor, i.e., the arterial vascular strain tensor, is the equivalent Second PK stress tensor, i.e., the arterial wall stress tensor, It should be noted that there is no limitation on the fitting parameters in this embodiment, which depends on the specific implementation situation.

[0133] Figure 6A schematic diagram of an evaluation parameter definition module provided in an embodiment of the present application. Based on the above embodiments, in some embodiments, such as Figure 6 As shown, the evaluation parameter definition module 13 includes:

[0134] The strain peak value acquisition module 131 is used to acquire the strain peak value during the blood vessel expansion stage.

[0135] The parameter definition submodule 132 is used to define the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance according to the stress-strain curve and the strain peak value.

[0136] In order to define the evaluation parameters, in this embodiment, the strain peak value acquisition module is used to obtain the strain peak value in the blood vessel expansion stage, and the parameter definition submodule is further used to define the blood vessel wall elastic potential energy reserve coefficient and the blood vessel wall strain resistance according to the stress-strain curve and the strain peak value. The definition method of the blood vessel wall elastic potential energy reserve coefficient is as follows:

[0137] ;

[0138] in, is the elastic potential energy reserve coefficient of the vascular wall, is the peak strain value, is the arterial vascular strain tensor, is the arterial wall stress tensor.

[0139] The definition of vascular wall strain resistance is as follows:

[0140] ;

[0141] in, is the vascular wall strain resistance, is the peak strain value, is the arterial vascular strain tensor, is the arterial wall stress tensor.

[0142] It should be noted that The indicator can be understood as Figure 5 The area under the stress-strain curve shown is obtained by integrating the curve. In general, The larger the index, the better, but different curves can still obtain the same Therefore, for For different targets with different values ​​or different periods of the same target, a single The index cannot distinguish the quality of vascular function. This just makes up for this deficiency. In simple terms, It reflects the difficulty of the blood vessel wall in storing elastic potential energy through deformation, so the same Under the indicator, The smaller it is, the better the blood vessel wall function.

[0143] Based on the above embodiments, in some embodiments, the vascular wall function assessment module 14 includes:

[0144] The evaluation and judgment module 141 is used to judge whether the elastic potential energy reserve coefficient of the blood vessel wall is not less than the first threshold value, and the blood vessel wall strain resistance is not greater than the second threshold value; if so, it is confirmed that the blood vessel wall function of the target part meets the preset requirements; if not, it is confirmed that the blood vessel wall function of the target part does not meet the preset requirements.

[0145] Specifically, after obtaining the vascular wall elastic potential energy reserve coefficient and vascular wall strain resistance of the target part of the target to be measured, it is necessary to determine the function of the vascular wall of the target part of the target to be measured based on these two parameters. In this embodiment, a first threshold is set for the vascular wall elastic potential energy reserve coefficient, and a second threshold is set for the vascular wall strain resistance. The evaluation and judgment module specifically determines whether the vascular wall elastic potential energy reserve coefficient is not less than the first threshold, and the vascular wall strain resistance is not greater than the second threshold. It should be noted that in this embodiment, there is no restriction on the first threshold and the second threshold, which depends on the specific implementation situation.

[0146] If it is confirmed that the vascular wall elastic potential energy reserve coefficient is not less than the first threshold value, and the vascular wall strain resistance is not greater than the second threshold value, then it is confirmed that the vascular wall function of the target part meets the preset requirements, and the vascular wall function of the target part of the target to be measured is good; if it is confirmed that the vascular wall elastic potential energy reserve coefficient is less than the first threshold value, and / or the vascular wall strain resistance is greater than the second threshold value, then it is confirmed that the vascular wall function of the target part does not meet the preset requirements, and the vascular wall function of the target part of the target to be measured is poor.

[0147] In this way, a quantitative assessment of vascular wall function is achieved, and the obtained vascular wall function parameters are more intuitive and better reflect the individual differences of the targets to be measured.

[0148] Figure 7 This is a schematic diagram of a device for quantitatively evaluating vascular wall function provided in an embodiment of the present application. Figure 7As shown, the present application also provides a vascular wall function quantitative evaluation device, including the above-mentioned vascular wall function quantitative evaluation device 1. The vascular wall function quantitative evaluation device can analyze and calculate the multi-phase image data of the target part obtained, reconstruct the multi-phase arterial vascular model, determine the phase corresponding to the vascular expansion stage, and complete the arterial strain analysis based on the multi-dimensional dynamic vascular model and displacement field information of the expansion stage; then combine the blood pressure information corresponding to each phase of the expansion stage to complete the stress analysis under each phase; based on the stress-strain result, fit the mechanical characteristic curve, use the mechanical characteristic fitting curve to complete the analysis and calculation of the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance, and determine the vascular wall function evaluation result of the target to be measured. Since the vascular wall elastic potential energy reserve coefficient describes the elastic potential energy stored in the arterial vascular expansion stage, and the vascular wall strain resistance reflects the difficulty of the vascular wall in storing elastic potential energy through deformation, based on the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance, combined with conventional clinical information, it is possible to make a personalized quantitative evaluation of the vascular function of the target to be measured, thereby improving the credibility of the vascular wall evaluation result.

[0149] In addition, the vascular wall function quantitative evaluation device also includes an output device 2, which can specifically send vascular wall function parameters, vascular wall strain resistance and vascular wall function evaluation results to the output device, and the output device displays the output externally to facilitate medical staff to quickly view the results, thereby improving diagnosis and treatment efficiency.

[0150] The above is a detailed introduction to a device and equipment for quantitatively evaluating vascular wall function provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

[0151] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A device for quantitatively evaluating vascular wall function, characterized in that: include: A multi-dimensional dynamic arterial blood vessel model building module, used to collect multi-phase arterial image data based on the target site, and to build a multi-dimensional dynamic arterial blood vessel model corresponding to the blood vessel expansion stage according to the arterial image data; A strain stress tensor determination module, used for determining an arterial blood vessel strain tensor and an arterial blood vessel wall stress tensor according to the multi-dimensional dynamic arterial blood vessel model; A curve fitting module, used for fitting the arterial blood vessel strain tensor and the arterial blood vessel wall stress tensor to obtain a stress-strain curve; An evaluation parameter definition module, used to define a vascular wall elastic potential energy reserve coefficient and a vascular wall strain resistance according to the stress-strain curve; A vascular wall function evaluation module, used to determine a vascular wall function evaluation result of the target site according to the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance; The multi-dimensional dynamic arterial blood vessel model building module includes: An arterial blood vessel model building module, used to build a multi-phase arterial blood vessel model according to the arterial image data; An expansion phase determination module, used to determine the phase corresponding to the blood vessel expansion phase according to the arterial blood vessel model; a displacement field information determination module, configured to determine the displacement field information according to the time phase corresponding to the blood vessel expansion stage and the arterial image data; wherein the displacement field information represents the displacement of the arterial blood vessel model at each time phase of the blood vessel expansion stage relative to the arterial blood vessel model at a reference time phase; the reference time phase is the blood vessel expansion start time phase or the blood vessel expansion end time phase; A superposition module, used for superimposing the arterial blood vessel model and the displacement field information to obtain the multi-dimensional dynamic arterial blood vessel model; The evaluation parameter definition module includes: A strain peak value acquisition module, used to obtain the strain peak value during the blood vessel expansion stage; A parameter definition submodule, used to define the vascular wall elastic potential energy reserve coefficient and the vascular wall strain resistance according to the stress-strain curve and the strain peak value; The definition of the vascular wall elastic potential energy reserve coefficient is as follows: ； in, is the elastic potential energy reserve coefficient of the vascular wall, is the peak strain value, is the arterial vascular strain tensor, is the arterial blood vessel wall stress tensor; The definition of the vascular wall strain resistance is as follows: ； in, is the vascular wall strain resistance, is the peak strain value, is the arterial vascular strain tensor, is the arterial wall stress tensor.

2. The device for quantitatively evaluating vascular wall function according to claim 1, characterized in that: The strain stress tensor determination module comprises: A first coordinate determination module, used to obtain the starting coordinates of the arterial blood vessel model at the starting phase of blood vessel expansion; A displacement field description function determination module, used to determine a displacement field description function according to the displacement field information; wherein the displacement field description function is a function of the coordinates of the arterial blood vessel model and time; A second coordinate determination module, used to determine the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage according to the starting coordinates and the displacement field description function; The arterial blood vessel strain tensor determination module is used to determine the arterial blood vessel strain tensor according to the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage.

3. The device for quantitatively evaluating vascular wall function according to claim 2, characterized in that: The arterial vascular strain tensor determination module comprises: A deformation gradient determination module, used to determine the deformation gradient according to the coordinates of the multi-dimensional dynamic arterial blood vessel model in the blood vessel expansion stage; The strain tensor calculation module is used to select a strain tensor calculation formula and determine the arterial blood vessel strain tensor according to the strain tensor calculation formula and the deformation gradient.

4. The device for quantitatively evaluating vascular wall function according to claim 2, characterized in that: The strain stress tensor determination module comprises: A blood pressure parameter acquisition module is used to obtain the blood pressure parameters corresponding to each time during the blood vessel expansion stage; The arterial blood vessel wall stress tensor determination module is used to determine the arterial blood vessel wall stress tensor according to the multi-dimensional dynamic arterial blood vessel model and the blood pressure parameter.

5. The device for quantitatively evaluating vascular wall function according to claim 4, characterized in that: The arterial blood vessel wall stress tensor determination module comprises: The equilibrium equation establishment module is used to establish a quasi-static equilibrium equation; wherein the quasi-static equilibrium equation is specifically as follows: ； in, is the current geometric position of the multi-dimensional dynamic arterial vascular model, is the Cauchy stress, is the mass force, is the predefined surface load, i.e., the blood pressure parameter; , is the external normal vector of the load application boundary, is the boundary to which the surface load is applied, is the deformation displacement; The Cauchy stress solving module is used to solve the Cauchy stress in the quasi-static equilibrium equation according to the multi-dimensional dynamic arterial blood vessel model and the blood pressure parameter to determine the arterial blood vessel wall stress tensor.

6. The device for quantitatively evaluating vascular wall function according to claim 1, characterized in that: The curve fitting module comprises: The fitting execution module is used to determine a target fitting formula, and fit the arterial vascular strain tensor and the arterial vascular wall stress tensor based on the target fitting formula to obtain the stress-strain curve; the target fitting formula is as follows: ； in, is the arterial vascular strain tensor, is the arterial wall stress tensor, is the fitting parameter.

7. The device for quantitatively evaluating vascular wall function according to claim 1, characterized in that: The vascular wall function assessment module comprises: The evaluation and judgment module is used to judge whether the elastic potential energy reserve coefficient of the blood vessel wall is not less than a first threshold value, and the blood vessel wall strain resistance is not greater than a second threshold value; if so, it is confirmed that the blood vessel wall function of the target part meets the preset requirements; if not, it is confirmed that the blood vessel wall function of the target part does not meet the preset requirements.

8. A device for quantitatively evaluating vascular wall function, characterized in that: A device for quantitatively evaluating vascular wall function comprising any one of claims 1 to 7.

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