Method and device for determining hemodynamic parameters, electronic equipment and storage medium

Abstract

The application provides a method and device for determining hemodynamic parameters, electronic equipment and a storage medium; a medical image is acquired, a target blood vessel is extracted from the medical image by using an image processing algorithm; the target blood vessel is segmented into a plurality of blood vessel segments according to a preset segmentation mode; for each blood vessel segment, an energy conservation equation and a mass conservation equation of the blood vessel segment are constructed according to the energy conservation law and the mass conservation law respectively; a control equation set of the blood vessel segment is constructed based on the energy conservation equation and the mass conservation equation of the blood vessel segment; and the hemodynamic parameters of each blood vessel segment are solved by simultaneously solving the control equation sets of the plurality of blood vessel segments. In this way, by segmenting the target blood vessel into blood vessel segments with monotonically changing blood vessel geometric parameters in the flow direction of blood, the geometric parameters such as the diameter and area of the blood vessel segment and upstream and downstream flow information are considered, and thus the hemodynamic parameters of the blood vessel segment can be more accurately calculated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluid dynamics, and in particular to a blood flow dynamics parameter determination method and device, an electronic device, and a storage medium. BACKGROUND

[0002] With the improvement of people's living standards, cardiovascular diseases have gradually become a threat to human health, especially coronary artery related diseases (CAD). At present, a gold standard for evaluating coronary artery lesions is invasive FFR; however, invasive FFR has high economic and time costs, and is also affected by drug allergy problems, which limits the scope of use of this technology. To solve this problem, more and more reliance is placed on CTA images for the diagnosis and treatment of coronary artery and other blood vessel related diseases, and blood flow dynamics parameters (such as FFR) of patients' blood vessels are determined through blood flow dynamics simulation, AI, and other methods. Since this method is a non-invasive method, it has a wider range of applications.

[0003] At present, the voltage and current in an analog circuit model are usually selected to solve the blood flow dynamics parameters involved in the blood vessels; the key to the analog circuit model is to accurately calculate the flow resistance in the blood vessels; in the prior art, the stenosis of the blood vessels (including both the contraction and expansion of the lumen) is treated as a whole blood vessel segment, which is difficult to handle for bifurcated lesions (branch blood vessels exist in the middle of the stenosis); at the same time, the influence of blood kinetic energy on static pressure change is not considered in the prior art. SUMMARY

[0004] Therefore, the present application aims to provide a blood flow dynamics parameter determination method and device, an electronic device, and a storage medium, which can more accurately calculate the blood flow dynamics parameters of the blood vessel segments by segmenting the blood vessels into blood vessel segments with monotonically varying blood vessel geometric parameters in the flow direction of the blood.

[0005] The present application provides a blood flow dynamics parameter determination method, which comprises:

[0006] Obtaining a medical image;

[0007] Extracting a target blood vessel from the medical image using an image processing algorithm;

[0008] Segmenting the target blood vessel into a plurality of blood vessel segments according to a preset segmentation method; wherein the blood vessel geometric parameters of each blood vessel segment have monotonicity in the flow direction of the blood in the blood vessel segment;

[0009] According to the energy conservation law and the mass conservation law, an energy conservation equation and a mass conservation equation of each blood vessel segment are constructed, respectively; the energy conservation equation is constructed based on the inlet mechanical energy at the inlet of the blood vessel segment, the outlet mechanical energy at the outlet of the blood vessel segment, and the mechanical energy loss caused by the blood flow in the blood vessel segment; the mass conservation equation is constructed based on the inlet blood flow of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0010] Based on the energy conservation equation and the mass conservation equation of the blood vessel segment, a control equation set of the blood vessel segment is constructed.

[0011] The control equation sets of the plurality of blood vessel segments are solved to obtain the hemodynamic parameters of each blood vessel segment; the hemodynamic parameters include the blood flow static pressure, the blood vessel segment flow, and the blood flow kinetic energy.

[0012] In a possible implementation, the target blood vessel is segmented into a plurality of blood vessel segments according to a preset segmentation manner, including:

[0013] The target blood vessel is cut into a plurality of blood vessel segments with equal lengths according to a preset segmentation length; or,

[0014] The target blood vessel is segmented into a plurality of blood vessel segments according to a specific cross-section.

[0015] In a possible implementation, the energy conservation equation and the mass conservation equation of each blood vessel segment are constructed according to the energy conservation law and the mass conservation law, respectively, including:

[0016] The inlet mechanical energy of each blood vessel segment is determined according to the sum of the inlet kinetic energy of each blood vessel inlet and the inlet static pressure of each blood vessel inlet of the blood vessel segment;

[0017] The outlet mechanical energy of each blood vessel segment is determined according to the sum of the outlet kinetic energy of each blood vessel outlet and the outlet static pressure of each blood vessel outlet of the blood vessel segment;

[0018] The mechanical energy loss caused by the blood flow through the blood vessel segment is determined based on the flow resistance of the blood vessel segment and the blood flow through the blood vessel segment;

[0019] According to the energy conservation principle, the energy conservation equation of the blood vessel segment is constructed by using the inlet mechanical energy at at least one inlet of the blood vessel segment, the outlet mechanical energy at the outlet of the blood vessel segment, and the mechanical energy loss of the blood vessel segment;

[0020] According to the mass conservation principle, the mass conservation equation of each blood vessel segment is constructed by using at least one inlet blood flow of each blood vessel segment and at least one outlet blood flow of each blood vessel segment.

[0021] In a possible implementation, the inlet kinetic energy of each blood vessel inlet is determined by the following steps:

[0022] For each blood vessel inlet, the blood vessel segment parameters involved in the blood vessel inlet are acquired; wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters;

[0023] A first function equation of the inlet kinetic energy of the blood vessel inlet is obtained based on the blood vessel segment parameters involved in the blood vessel inlet, by using the functional relationship between the inlet kinetic energy of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0024] In a possible implementation, the outlet kinetic energy of each blood vessel outlet is determined by the following steps:

[0025] For each blood vessel outlet, the blood vessel segment parameters involved in the blood vessel outlet are acquired; wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters;

[0026] A second function equation of the outlet kinetic energy of the blood vessel outlet is obtained based on the blood vessel segment parameters involved in the blood vessel outlet, by using the functional relationship between the outlet kinetic energy of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0027] In a possible implementation, the flow resistance of the blood vessel segment is determined by the following steps:

[0028] A third function equation of the flow resistance of the blood vessel segment is obtained based on the blood vessel segment parameters of the blood vessel segment, by using the functional relationship between the flow resistance of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0029] In a possible implementation, the flow resistance includes a first resistance term having a linear relationship with the blood flow rate and a second resistance term having a non-linear relationship with the blood flow rate.

[0030] The application further provides a blood flow dynamics parameter determination device, which comprises:

[0031] An image acquisition module is configured to acquire medical images.

[0032] A blood vessel extraction module is configured to extract a target blood vessel from the medical images by using an image processing algorithm.

[0033] A blood vessel segmentation module is configured to segment the target blood vessel into a plurality of blood vessel segments according to a preset segmentation manner; wherein the blood vessel geometric parameters of each blood vessel segment have monotonicity in the blood flow direction of the blood vessel segment.

[0034] a first equation constructing module, configured to construct, for each blood vessel segment, an energy conservation equation and a mass conservation equation of the blood vessel segment according to the law of conservation of energy and the law of conservation of mass respectively; wherein the energy conservation equation is constructed based on an inlet mechanical energy at an inlet of the blood vessel segment, an outlet mechanical energy at an outlet of the blood vessel segment, and a mechanical energy loss caused by blood flow in the blood vessel segment; and the mass conservation equation is constructed based on an inlet blood flow of the blood vessel segment and an outlet blood flow of the blood vessel segment;

[0035] a second equation constructing module, configured to construct a control equation group of the blood vessel segment based on the energy conservation equation and the mass conservation equation of the blood vessel segment;

[0036] a parameter determining module, configured to solve a hemodynamic parameter of each blood vessel segment by simultaneously solving the control equation groups of the plurality of blood vessel segments; wherein the hemodynamic parameter comprises a blood flow static pressure, a blood vessel segment flow, and a blood flow kinetic energy.

[0037] In a possible implementation, when the blood vessel segmenting module is used to segment the target blood vessel into a plurality of blood vessel segments according to a preset segmentation manner, the blood vessel segmenting module is configured to:

[0038] cut the target blood vessel into a plurality of blood vessel segments with equal lengths according to a preset segmentation length; or

[0039] segment the target blood vessel into a plurality of blood vessel segments according to a specific cross section.

[0040] In a possible implementation, when the first equation constructing module is used to construct, for each blood vessel segment, an energy conservation equation and a mass conservation equation of the blood vessel segment according to the law of conservation of energy and the law of conservation of mass respectively, the first equation constructing module is configured to:

[0041] determine, for each blood vessel segment, an inlet mechanical energy of the blood vessel segment according to a sum of an inlet kinetic energy of each blood vessel inlet of the blood vessel segment and an inlet static pressure of each blood vessel inlet;

[0042] determine an outlet mechanical energy of the blood vessel segment according to a sum of an outlet kinetic energy of each blood vessel outlet of the blood vessel segment and an outlet static pressure of each blood vessel outlet;

[0043] determine a mechanical energy loss caused by blood flowing through the blood vessel segment based on a flow resistance of the blood vessel segment and a blood flow through the blood vessel segment; and construct an energy conservation equation of the blood vessel segment according to the law of conservation of energy, by using the inlet mechanical energy at at least one inlet of the blood vessel segment, the outlet mechanical energy at the outlet of the blood vessel segment, and the mechanical energy loss of the blood vessel segment;

[0044] According to the mass conservation principle, a mass conservation equation of each blood vessel segment is constructed by using at least one inlet blood flow of each blood vessel segment and at least one outlet blood flow of each blood vessel segment.

[0045] In a possible implementation, the first equation construction module is configured to determine the inlet kinetic energy of each blood vessel inlet by the following steps:

[0046] For each blood vessel inlet, blood vessel segment parameters related to the blood vessel inlet are obtained, wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters.

[0047] A first function equation of the inlet kinetic energy of the blood vessel inlet is obtained based on the blood vessel segment parameters related to the blood vessel inlet by using a function relationship between the inlet kinetic energy of the blood vessel segment and the inlet blood flow of the blood vessel segment.

[0048] In a possible implementation, the first equation construction module is configured to determine the outlet kinetic energy of each blood vessel outlet by the following steps:

[0049] For each blood vessel outlet, blood vessel segment parameters related to the blood vessel outlet are obtained, wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters.

[0050] A second function equation of the outlet kinetic energy of the blood vessel outlet is obtained based on the blood vessel segment parameters related to the blood vessel outlet by using a function relationship between the outlet kinetic energy of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0051] In a possible implementation, the first equation construction module is configured to determine the flow resistance of the blood vessel segment by the following steps:

[0052] A third function equation of the flow resistance of the blood vessel segment is obtained based on the blood vessel segment parameters of the blood vessel segment by using a function relationship between the flow resistance of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0053] In a possible implementation, the flow resistance includes a first resistance term having a linear relationship with a blood flow rate and a second resistance term having a non-linear relationship with the blood flow rate.

[0054] The embodiments of the present application also provide an electronic device, which comprises a processor, a memory and a bus, the memory stores machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and the machine readable instructions are executed by the processor to perform the steps of the blood flow dynamics parameter determination method as described above.

[0055] The embodiment of the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is run by a processor to perform the steps of the method for determining a hemodynamic parameter.

[0056] The method for determining a hemodynamic parameter, the device, the electronic equipment and the storage medium provided by the embodiment of the present application obtain a medical image; a target blood vessel is extracted from the medical image by using an image processing algorithm; the target blood vessel is segmented into a plurality of blood vessel segments according to a preset segmentation manner; wherein the blood vessel geometric parameters of each blood vessel segment have monotonicity in the flow direction of blood in the blood vessel segment; for each blood vessel segment, an energy conservation equation and a mass conservation equation of each blood vessel segment are constructed according to the energy conservation law and the mass conservation law respectively; a control equation group of the blood vessel segment is constructed based on the energy conservation equation and the mass conservation equation of the blood vessel segment; and the hemodynamic parameters of each blood vessel segment are solved by simultaneously solving the control equation groups of the plurality of blood vessel segments. In this way, by segmenting the target blood vessel into blood vessel segments with monotonically changing blood vessel geometric parameters in the flow direction of blood, the blood vessel segment hemodynamic parameters of the blood vessel segments can be more accurately calculated.

[0057] In order to make the above objectives, characteristics and advantages of the present application more apparent and comprehensible, the following will specifically describe preferred embodiments in combination with the accompanying drawings, and make a detailed description as follows. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0059] Figure 1 A flow chart of a method for determining a hemodynamic parameter provided by the embodiment of the present application;

[0060] Figure 2 A construction flowchart of a control equation group of a blood vessel segment provided by the embodiment of the present application;

[0061] Figure 3 A structural schematic diagram of a device for determining a hemodynamic parameter provided by the embodiment of the present application;

[0062] Figure 4 A structural schematic diagram of an electronic equipment provided by the embodiment of the present application. DETAILED DESCRIPTION

[0063] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application and not all embodiments of the present application. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, every other embodiment obtained by a person skilled in the art without creative work belongs to the scope of protection of the present application.

[0064] It is found through research that at present, the way of voltage and current in an analog circuit model is usually selected to solve the blood flow hemodynamic parameters involved in a blood vessel; the key of the analog circuit model lies in accurately calculating the flow resistance in the blood vessel; in the prior art, the calculation way of the flow resistance is specifically as follows: one is that the flow resistance is simulated by three-dimensional simulation, the flow resistance is obtained by regression of three-dimensional simulation results, response surface and the like through multiple three-dimensional simulations in advance, and then the blood flow hemodynamic parameters in the blood vessel are calculated; however, this way needs multiple simulation tests in advance, and has a large demand for calculation resources and actual calculation time; the other is that the flow resistance is obtained by a theoretical formula, and a special model is adopted to calculate and obtain the flow resistance for a stenosis section in a blood vessel; however, the stenosis (including both contraction and expansion of a lumen) of the blood vessel is processed as a whole blood vessel section, which has difficulty in processing a bifurcation lesion (a branch blood vessel exists in the middle of the stenosis); meanwhile, the influence of blood kinetic energy on static pressure change is not considered in the prior art.

[0065] Based on this, the embodiments of the present application provide a blood flow hemodynamic parameter determination method, which can efficiently calculate the blood flow hemodynamic parameters of a target blood vessel by means of an analog circuit; and in the calculation process, the target blood vessel is divided into multiple blood vessel sections with a monotonous change trend of blood vessel geometric parameters in the flow direction of blood in the blood vessel section, the change trend of geometric parameters such as diameter and area of the blood vessel section and the information of upstream and downstream are considered when calculating the blood flow parameters of each blood vessel section, and the influence of kinetic energy is also considered, so that the blood flow hemodynamic parameters of the blood vessel section can be more accurately calculated.

[0066] Reference is made to Figure 1 , Figure 1 A flowchart of a blood flow hemodynamic parameter determination method provided by the embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the blood flow hemodynamic parameter determination method provided by the embodiments of the present application comprises the following steps. Figure 1 ​

[0067] S101, acquire a medical image.

[0068] S102, extract a target blood vessel from the medical image by using an image processing algorithm.

[0069] S103, segment the target blood vessel into a plurality of blood vessel segments according to a preset segmentation manner, wherein a blood vessel geometric parameter of each blood vessel segment has monotonicity in a blood flow direction of the blood vessel segment.

[0070] S104, for each blood vessel segment, construct an energy conservation equation and a mass conservation equation of the blood vessel segment according to the energy conservation law and the mass conservation law respectively.

[0071] S105, construct a control equation group of the blood vessel segment based on the energy conservation equation and the mass conservation equation of the blood vessel segment.

[0072] S106, solve the hemodynamic parameters of each blood vessel segment by simultaneously solving the control equation groups of the plurality of blood vessel segments.

[0073] The embodiment of the present application provides a method for determining hemodynamic parameters. The target blood vessel is extracted from the acquired medical image, and the target blood vessel is segmented into a plurality of blood vessel segments with monotonous blood vessel geometric parameters in the blood flow direction according to a preset segmentation manner. Further, the energy conservation equation and the mass conservation equation of each blood vessel segment can be constructed according to the energy conservation law and the mass conservation law. Therefore, when calculating the hemodynamic parameters of the blood vessel segment, the change trend of the blood vessel geometric parameters of the blood vessel segment, such as the change trend of the diameter and area of the blood vessel segment, can be combined, and the hemodynamic parameters of each blood vessel segment can be calculated more accurately.

[0074] The medical image can include CT angiography (CTA) and other images that can obtain blood vessels.

[0075] When determining the hemodynamic parameters related to the blood vessels, the blood vessels need to be segmented from the original CTA image, that is, the information unrelated to the blood vessels in the CTA image is removed, so as to reduce the interference on the calculation process and the calculation amount.

[0076] In step S102, the existing image processing algorithm can be used, such as the threshold method, the filtering method, the minimum cost path method and other traditional image algorithms. In addition, machine learning algorithms such as neural network algorithm and deep learning algorithm can also be used. The target blood vessel for calculating the hemodynamic parameters is extracted from the medical image by using the above image processing algorithm.

[0077] Here, the obtained target vessel can be a complete three-dimensional vessel geometry model or a set of vessel profile curves representing key positions of the vessel.

[0078] In step S103, the segmented target vessel is segmented along the blood flow direction in the target vessel according to a preset segmentation manner. Specifically, the complete three-dimensional vessel geometry model of the segmented target vessel can be segmented, or the set of vessel profile curves of the target vessel can be segmented.

[0079] In the segmentation, the vessel geometry parameter of each position in the target vessel is considered, and the coronary vessel is segmented into a plurality of vessel segments, so that the vessel geometry parameter of the segmented vessel segment has monotonicity in the blood flow direction in the vessel segment, that is, the vessel geometry parameter of the segmented vessel segment monotonically increases or monotonically decreases along the blood flow direction in the vessel segment.

[0080] Here, the vessel geometry parameter includes the diameter, radius, and area of the vessel segment, etc. For example, the diameter of the vessel segment monotonically increases along the blood flow direction, or the diameter of the vessel segment monotonically decreases along the blood flow direction.

[0081] In an embodiment, step S103 includes: cutting the coronary vessel into a plurality of vessel segments with equal lengths according to a preset segmentation length.

[0082] In this step, the segmentation length can be preset when the target vessel is segmented, for example, 0.1 cm. The target vessel is cut into a plurality of vessel segments with equal lengths according to the preset segmentation length. Here, since the preset segmentation length is small enough, the vessel geometry parameter of the coronary vessel in the preset segmentation length range must have monotonicity. Therefore, the vessel geometry parameter of the vessel segment segmented according to the preset segmentation length has monotonicity along the blood flow direction.

[0083] Or, the target vessel is segmented into a plurality of vessel segments according to a specific cross section.

[0084] In this step, a specific cross section can be determined in the target vessel in advance, for example, the most narrow cross section or the largest lumen profile cross section in the target vessel. In this way, the segmentation position of the target vessel is limited, so that the vessel geometry parameter of the vessel segment segmented according to the specific cross section has monotonicity along the blood flow direction.

[0085] In step S104, for each segmented blood vessel, firstly, based on the law of conservation of energy, an energy conservation equation for the blood vessel segment is constructed based on the inlet mechanical energy at the inlet of the blood vessel segment and the outlet mechanical energy at the outlet of the blood vessel segment; here, the inlet mechanical energy at the inlet of the blood vessel segment refers to the sum of the inlet mechanical energy of all blood vessel inlets of the blood vessel segment; the outlet mechanical energy at the outlet of the blood vessel segment refers to the sum of the outlet mechanical energy of all blood vessel outlets of the blood vessel segment.

[0086] Then, based on the law of conservation of mass, the mass conservation equation for the blood vessel segment is constructed based on the inlet blood vessel flow rate and the outlet blood vessel flow rate of the blood vessel segment. Similarly, here, the inlet blood vessel flow rate of the blood vessel segment refers to the sum of the inlet blood vessel flow rates of all blood vessel inlets of the blood vessel segment; the outlet blood vessel flow rate of the blood vessel segment refers to the sum of the outlet blood vessel flow rates of all blood vessel outlets of the blood vessel segment.

[0087] In one embodiment, step S104 includes: Step 1, for each blood vessel segment, determining the inlet mechanical energy of the blood vessel segment based on the sum of the inlet kinetic energy of each blood vessel inlet and the inlet static pressure of each blood vessel inlet.

[0088] In hemodynamics, the mechanical energy at the inlet of a blood vessel includes the pressure potential energy and kinetic energy at the inlet location; where the pressure potential energy is the static pressure at the inlet, that is, the mechanical energy at the inlet is the sum of the inlet kinetic energy and the inlet static pressure. The mechanical energy at the outlet of a blood vessel includes the pressure potential energy and kinetic energy at the outlet location; where the pressure potential energy is the static pressure at the outlet, then the mechanical energy at the outlet is the sum of the outlet kinetic energy and the outlet static pressure.

[0089] According to the principle of conservation of energy, when blood flows from one end of a blood vessel to the other, the mechanical energy at the entrance of that blood vessel segment should be equal to the sum of the mechanical energy at the exit of that blood vessel segment and the mechanical energy loss generated during the blood flow.

[0090] In this step, for each blood vessel segment, the sum of the inlet kinetic energy of each blood vessel inlet in the segment and the inlet static pressure of each blood vessel inlet is determined as the inlet mechanical energy of the segment; that is, the sum of the inlet kinetic energy of all blood vessel inlets in the segment and the inlet static pressure of all blood vessel inlets is the inlet mechanical energy of the segment.

[0091] Step 2: Determine the outlet mechanical energy at the outlet of the blood vessel segment based on the sum of the outlet kinetic energy and the outlet static pressure of each blood vessel outlet.

[0092] In this step, for each blood vessel segment, the sum of the outlet kinetic energy of each blood vessel outlet in the blood vessel segment and the outlet static pressure of each blood vessel outlet is determined as the outlet mechanical energy of the blood vessel segment; that is, the sum of the outlet kinetic energy of all blood vessel outlets in the blood vessel segment and the outlet static pressure of all blood vessel outlets is the outlet mechanical energy of the blood vessel segment.

[0093] In step 3, based on the flow resistance of the blood vessel segment and the blood flow through the blood vessel segment, the mechanical energy loss generated when the blood flows through the blood vessel segment is determined.

[0094] In this step, for each blood vessel segment, the mechanical energy loss generated when the blood flows through the blood vessel segment is determined based on the flow resistance existing in the blood vessel segment and the outlet blood flow of the blood vessel segment, considering the existence of the mechanical energy loss generated when the blood flows in the blood vessel segment.

[0095] The blood flow through the blood vessel segment includes the inlet blood flow of the blood vessel segment, the outlet blood flow of the blood vessel segment, or other forms such as a combination between the inlet blood flow of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0096] The flow resistance includes a first resistance term having a first power relationship with the blood flow rate and a second resistance term having a non-first power relationship with the blood flow rate.

[0097] Specifically, the first resistance term is mostly referred to as viscous force term in fluid mechanics; the second resistance term refers to the change of the velocity distribution, flow pattern, etc. of the blood in the lumen due to the change of the geometric parameters, such as the narrowing or expansion of the lumen or the bending of the pipeline, thereby affecting the fluid energy loss; in addition, the second resistance term is also related to the blood flow rate in the blood vessel segment.

[0098] Specifically, the mechanical energy loss is determined according to the flow resistance of the blood vessel segment and the outlet blood flow of the blood vessel segment, and specifically, the mechanical energy loss of the blood vessel segment is calculated by the following formula:

[0099] Δp=qR=q(R1+R2);

[0100] Where ΔP is the mechanical energy loss of the blood vessel segment, q is the blood flow through the blood vessel segment, here, the blood flow through the blood vessel segment for calculating the mechanical energy loss can include the inlet blood flow of the blood vessel segment, the outlet blood flow of the blood vessel segment or other forms (for example, a combination between the inlet blood flow of the blood vessel segment and the outlet blood flow of the blood vessel segment), R is the flow resistance, R1 is the first resistance term, and R2 is the second resistance term.

[0101] Step 4, according to the principle of energy conservation, an energy conservation equation is constructed by using the inlet mechanical energy of at least one inlet of the blood vessel segment, the outlet mechanical energy of the outlet of the blood vessel segment, and the mechanical energy loss of the blood vessel segment, to obtain the energy conservation equation of the blood vessel segment.

[0102] In this step, according to the principle of energy conservation, a mechanical energy equation is constructed by using the inlet mechanical energy of the blood vessel segment and the outlet mechanical energy of the blood vessel segment, to obtain the energy conservation equation of the blood vessel segment; specifically, the energy conservation equation of the blood vessel segment obtained by construction is:

[0103] p1+E k1 =p2+E k2 +ΔP=p2+E k2 +q(R1+R2);

[0104] Wherein, E k1 is the inlet kinetic energy of the blood vessel segment, E k2 is the outlet kinetic energy of the blood vessel segment, p1 is the inlet static pressure of the blood vessel segment, p2 is the outlet static pressure of the blood vessel segment, ΔP is the mechanical energy loss of the blood vessel segment, q is the blood flow through the blood vessel segment, R1 is the first resistance term, and R2 is the second resistance term.

[0105] Step 5, according to the principle of mass conservation, a mass conservation equation is constructed by using at least one inlet blood flow of each blood vessel segment and at least one outlet blood flow of each blood vessel segment, to obtain the mass conservation equation of the blood vessel segment.

[0106] In this step, according to the principle of mass conservation, a mass conservation equation is constructed by using at least one inlet blood flow of the blood vessel segment and at least one outlet blood flow of the blood vessel segment, to obtain the mass conservation equation of the blood vessel segment; here, the inlet blood flow of the blood vessel segment is the sum of the inlet blood flows of all the inlets of the blood vessel segment; similarly, the outlet blood flow of the blood vessel segment is the sum of the outlet blood flows of all the outlets of the blood vessel segment; specifically, the mass conservation equation of the blood vessel segment obtained by construction is:

[0107] q1=q2;

[0108] Wherein, q1 is the inlet blood flow of the blood vessel segment, and q2 is the outlet blood flow of the blood vessel segment.

[0109] In one embodiment, the inlet kinetic energy of each blood vessel inlet is determined by the following steps: for each blood vessel inlet, the blood vessel segment parameters involved in the blood vessel inlet are obtained; based on the blood vessel segment parameters involved in the blood vessel inlet, a first function equation of the inlet kinetic energy of the blood vessel inlet is obtained by using the functional relationship between the inlet kinetic energy of the blood vessel segment and the inlet blood flow of the blood vessel segment.

[0110] In this step, for each blood vessel inlet, a first functional equation representing the inlet kinetic energy of each blood vessel inlet is determined respectively; specifically, for each blood vessel inlet, the blood vessel segment parameters involved in the blood vessel inlet are obtained, the blood vessel segment parameters are substituted into the functional relationship between the inlet kinetic energy of the blood vessel segment and the inlet blood flow of the blood vessel segment, and the first functional equation of the inlet kinetic energy of the blood vessel inlet is obtained.

[0111] For example, the first functional equation of the inlet kinetic energy is:

[0112] E k1 = f e1 (x1, q1);

[0113] wherein E k1 is the inlet kinetic energy of the blood vessel segment, x1 is the blood vessel segment parameter involved in the blood vessel inlet, q1 is the inlet blood flow of the blood vessel segment, f e1 is the functional relationship between the inlet kinetic energy of the blood vessel segment and the inlet blood flow of the blood vessel segment.

[0114] Here, the functional relationship can include the Poiseuille theorem, etc.

[0115] In an embodiment, the inlet kinetic energy and the inlet blood flow can have the following functional relationship:

[0116]

[0117] wherein E k1 is the inlet kinetic energy of the blood vessel segment, α1 is the inlet kinetic energy correction coefficient, ρ is the blood density, u m1 is the average flow velocity of the inlet cross section.

[0118] Here, the optimal value range of the inlet kinetic energy correction coefficient α1 is between 1 and 3.

[0119] wherein u m1 =q1 / A1; q1 is the inlet blood flow of the blood vessel segment, and A1 is the area of the blood vessel inlet.

[0120] In other embodiments, the inlet kinetic energy can also be predicted by a pre-obtained machine learning model, which can be determined according to actual conditions and is not limited here.

[0121] The vessel segment parameters include vessel segment body parameters and upstream and downstream vessel segment geometry parameters. The vessel segment body parameters include the diameters of the inlet and outlet of the vessel segment, the length of the vessel segment, the volume of the vessel segment, the bending angle of the inlet and outlet face normal vector, the curvature radius, and the like. In addition, some vessel segment related upstream and downstream information of the vessel segment is involved. The upstream and downstream information of the vessel segment reflects the influence of the upstream and downstream vessel segments (the upstream and downstream vessel segments of the current vessel segment along the blood flow direction) on the current vessel segment. Specifically, the upstream and downstream information of the vessel segment can include the bending angle of the upstream and downstream vessel segments, the bending angle of the upstream and downstream vessel segments, the curvature, and the like.

[0122] In an embodiment, the outlet kinetic energy of each vessel outlet is determined by the following steps: for each vessel outlet, the vessel segment parameters related to the vessel outlet are obtained; and based on the vessel segment parameters related to the vessel outlet, the second function equation of the outlet kinetic energy of the vessel outlet is obtained by using the function relationship between the outlet kinetic energy of the vessel segment and the outlet blood flow of the vessel segment.

[0123] In this step, for each vessel outlet, the second function equation of the outlet kinetic energy of each vessel outlet is determined respectively. Specifically, for each vessel outlet, the vessel segment parameters related to the vessel outlet are obtained, the vessel segment parameters are substituted into the function relationship between the outlet kinetic energy of the vessel segment and the outlet blood flow of the vessel segment, and the second function equation of the outlet kinetic energy of the vessel outlet is obtained.

[0124] For example, the second function equation of the outlet kinetic energy is as follows:

[0125] E k2 = f e2 (x2, q2);

[0126] wherein E k2 is the outlet kinetic energy of the vessel segment outlet, x2 is the vessel segment parameter related to the vessel outlet, q2 is the outlet blood flow of the vessel segment, and f e2 is the function relationship between the outlet kinetic energy of the vessel segment and the outlet blood flow of the vessel segment.

[0127] Here, the function relationship can include the Poiseuille theorem and the like.

[0128] In an embodiment, the function relationship between the outlet kinetic energy and the outlet blood flow can be as follows:

[0129]

[0130] wherein E k2 is the outlet kinetic energy of the vessel segment outlet, a2 is the outlet kinetic energy correction coefficient, p is the blood density, and u m2 is the average flow velocity of the outlet cross section.

[0131] Here, the optimal value range of the outlet kinetic energy correction coefficient a2 is between 1 and 3.

[0132] Wherein, u m2 = q2 / A2; q2 is the outlet blood flow of the blood vessel segment, and A2 is the outlet area of the blood vessel.

[0133] In other embodiments, the outlet kinetic energy can also be predicted by a pre-obtained machine learning model, which can be determined according to actual conditions, which is not limited here.

[0134] Wherein, the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters; here, the blood vessel segment body parameters include the diameters of the inlet / outlet of the blood vessel segment, the length of the blood vessel segment, the volume of the blood vessel segment, the bending angle of the inlet / outlet normal vector, the curvature radius and other parameters; in addition, some blood vessel segment related upstream and downstream information of the blood vessel segment is also involved, which reflects the influence of the upstream and downstream blood vessel segments (the upstream and downstream blood vessel segments of the current blood vessel segment along the blood flow direction) on the current blood vessel segment; specifically, the upstream and downstream information of the blood vessel segment can include the bending angle of the upstream and downstream blood vessel segments, the bending angle of the upstream and downstream blood vessel segments, the curvature and other information.

[0135] In one embodiment, the flow resistance of the blood vessel segment is determined by the following steps: obtaining a third function equation of the flow resistance of the blood vessel segment based on the blood vessel segment parameters of the blood vessel segment by using the functional relationship between the flow resistance of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0136] In this step, for each blood vessel segment, a third function equation of the flow resistance of each blood vessel segment is determined; specifically, for each blood vessel segment, the blood vessel segment parameters of the blood vessel segment are obtained, and the blood vessel segment parameters are substituted into the functional relationship between the flow resistance of the blood vessel segment and the outlet blood flow of the blood vessel segment to obtain the third function equation of the flow resistance of the blood vessel segment.

[0137] Here, the flow resistance includes a first resistance term and a second resistance term, the functional relationship between the first resistance term and the outlet blood flow is inconsistent with the functional relationship between the second resistance term and the outlet blood flow;

[0138] For example, the third function equation of the first resistance term is:

[0139] R1 = f r1 (x2, q);

[0140] Wherein, R1 is the first resistance term, x2 is the blood vessel segment parameter related to the blood vessel outlet, q is the blood flow through the blood vessel segment, f r1The function relationship between the first resistance term and the blood flow through the vessel segment can include Poiseuille's law, etc.

[0141] The function relationship can include Poiseuille's law, etc.

[0142] In an embodiment, the first resistance term can have the following function relationship:

[0143]

[0144] wherein R1 is the first resistance term, μ is the blood viscosity, L is the vessel segment length, and d is the lumen profile diameter.

[0145] The lumen profile diameter can be any one of the lumen profile diameter at the vessel outlet, the lumen profile diameter at the vessel inlet, the lumen profile diameter at a middle position of the vessel segment, the average of the lumen profile diameters at various positions of the vessel segment, and the lumen profile diameter obtained by integrating the diameters of the vessel segment along the blood flow direction.

[0146] In addition, the first resistance term in the vessel segment can also be predicted by a pre-trained machine learning model according to the blood viscosity, the vessel segment length of the vessel segment, and the lumen profile diameter of the vessel segment, which can be determined according to actual conditions and is not limited herein.

[0147] For example, the third function equation of the second resistance term is:

[0148] R2 = f r2 (x2, q);

[0149] wherein R2 is the second resistance term, x2 is the vessel segment parameter of the vessel segment, q is the blood flow through the vessel segment, and f r2 The function relationship between the second resistance term and the blood flow through the vessel segment can include Poiseuille's law, etc.

[0150] The function relationship can include Poiseuille's law, etc.

[0151] In other implementations, the second resistance term can be determined by a pre-trained machine learning model; the machine learning model used to calculate the second resistance term is trained using a pre-obtained dataset; after obtaining the trained machine learning model for calculating the second resistance term, the corresponding second resistance term can be obtained through the machine learning model.

[0152] In step S105, for each blood vessel segment, the energy conservation equation and the mass conservation equation of that blood vessel segment together constitute the governing equation set of that blood vessel segment.

[0153] In step S106, the dynamic parameters of each blood vessel segment are obtained by solving the control equations of each segment simultaneously. The hemodynamic parameters include hemostatic pressure, blood flow rate, and hemodynamic energy. The hemostatic pressure includes the inlet static pressure of each vessel inlet and the outlet static pressure of each vessel outlet in the segment. The blood flow rate includes the inlet blood flow rate of each vessel inlet and the outlet blood flow rate of each vessel outlet in the segment. The hemodynamic energy includes the inlet kinetic energy of each vessel inlet and the outlet kinetic energy of each vessel outlet in the segment.

[0154] Simultaneously, to ensure the control equations are closed (having a unique solution), boundary conditions are applied to the target vessel (such as a complete coronary tree containing the aorta). These boundary conditions are at the inlet and outlet, and can be of the types of flow rate and flow resistance or static pressure. For example, one method for specifying boundary conditions is as follows: in a coronary artery problem, the inlet blood flow rate is calculated based on the myocardial volume and empirical formulas; then, based on the blood flow rate, the flow resistance R at each outlet of the entire vessel is obtained using empirical formulas.

[0155] Please see Figure 2 , Figure 2 This is a schematic diagram illustrating the construction process of a set of governing equations for a blood vessel segment provided in an embodiment of this application. Figure 2 As shown, step S201: Acquire medical images; step S202: Extract the target blood vessel from the medical images; step S203: Divide the target blood vessel into multiple segments; step S204: Extract blood vessel segment parameters from each segment; step S205: Determine the first resistance term in the blood vessel segment based on the segment parameters; step S206: Determine the second resistance term in the blood vessel segment based on the segment parameters; step S207: Determine the inlet kinetic energy of each blood vessel inlet in the segment based on the segment parameters; step S208: Determine the outlet kinetic energy of each blood vessel outlet in the segment based on the segment parameters; step S209: Construct the energy conservation equation and mass conservation equation for each blood vessel segment based on the laws of conservation of energy and conservation of mass; step S210: Construct the governing equations for the blood vessel segment based on the energy conservation equation and mass conservation equation for that segment.

[0156] The method for determining hemodynamic parameters provided in this application involves acquiring medical images; extracting target blood vessels from the medical images using image processing algorithms; dividing the target blood vessel into multiple segments according to a preset segmentation method; wherein the vascular geometric parameters of each segment are monotonic in the direction of blood flow within that segment; for each segment, constructing energy conservation equations and mass conservation equations based on the laws of energy conservation and mass conservation; constructing a set of governing equations for that segment based on these equations; and solving the set of governing equations for multiple segments to obtain the hemodynamic parameters for each segment. Thus, by segmenting the blood vessel into segments whose vascular geometric parameters monotonically change in the direction of blood flow, the hemodynamic parameters of each segment can be calculated more accurately.

[0157] Please see Figure 3 , Figure 3 This is a schematic diagram of a device for determining hemodynamic parameters provided in an embodiment of this application. Figure 3 As shown, the determining device 300 includes:

[0158] Image acquisition module 310 is used to acquire medical images;

[0159] The blood vessel extraction module 320 is used to extract target blood vessels from the medical image using image processing algorithms;

[0160] The blood vessel segmentation module 330 is used to segment the target blood vessel into multiple blood vessel segments according to a preset segmentation method; wherein the blood vessel geometry parameters of each blood vessel segment are monotonic in the direction of blood flow in that blood vessel segment.

[0161] The first equation construction module 340 is used to construct, for each blood vessel segment, an energy conservation equation and a mass conservation equation for each segment, based on the laws of conservation of energy and mass, respectively. The energy conservation equation is constructed based on the inlet mechanical energy at the inlet of the blood vessel segment, the outlet mechanical energy at the outlet of the blood vessel segment, and the mechanical energy loss caused by blood flow within the blood vessel segment. The mass conservation equation is constructed based on the inlet blood flow rate and the outlet blood flow rate of the blood vessel segment.

[0162] The second equation construction module 350 is used to construct the governing equations of the blood vessel segment based on the energy conservation equation and the mass conservation equation of the blood vessel segment.

[0163] The parameter determination module 360 is configured to solve the hemodynamic parameters of each blood vessel segment by simultaneously solving the control equation set of the plurality of blood vessel segments, wherein the hemodynamic parameters include blood flow static pressure, blood vessel segment flow, and blood flow kinetic energy.

[0164] Further, when the blood vessel segmentation module 330 is configured to segment the target blood vessel into a plurality of blood vessel segments according to a preset segmentation manner, the blood vessel segmentation module 330 is configured to:

[0165] cut the target blood vessel into a plurality of blood vessel segments with equal lengths according to a preset segmentation length; or

[0166] segment the target blood vessel into a plurality of blood vessel segments according to a specific cross-section.

[0167] Further, when the first equation construction module 340 is configured to construct the energy conservation equation and the mass conservation equation of each blood vessel segment according to the law of conservation of energy and the law of conservation of mass, respectively, the first equation construction module 340 is configured to:

[0168] determine the inlet mechanical energy of each blood vessel segment according to the sum of the inlet kinetic energy of each blood vessel inlet and the inlet static pressure of each blood vessel inlet of the blood vessel segment;

[0169] determine the outlet mechanical energy of the blood vessel segment according to the sum of the outlet kinetic energy of each blood vessel outlet and the outlet static pressure of each blood vessel outlet of the blood vessel segment;

[0170] determine the mechanical energy loss generated when blood flows through the blood vessel segment based on the flow resistance of the blood vessel segment and the blood flow through the blood vessel segment;

[0171] construct an energy conservation equation according to the energy conservation principle, using the inlet mechanical energy at at least one inlet of the blood vessel segment, the outlet mechanical energy at the outlet of the blood vessel segment, and the mechanical energy loss of the blood vessel segment, to obtain the energy conservation equation of the blood vessel segment;

[0172] construct a mass conservation equation according to the mass conservation principle, using the blood flow at at least one inlet of each blood vessel segment and the blood flow at at least one outlet of each blood vessel segment, to obtain the mass conservation equation of the blood vessel segment.

[0173] Further, the first equation construction module 340 is configured to determine the inlet kinetic energy of each blood vessel inlet by the following steps:

[0174] for each blood vessel inlet, obtain the blood vessel segment parameters related to the blood vessel inlet, wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters;

[0175] The first function equation of the inlet kinetic energy of the blood vessel inlet is obtained based on the blood vessel segment parameters related to the blood vessel inlet, by using a function relationship between the inlet kinetic energy of the blood vessel segment and the inlet blood flow of the blood vessel segment.

[0176] Further, the first equation construction module 340 is configured to determine the outlet kinetic energy of each blood vessel outlet by the following steps:

[0177] For each blood vessel outlet, the blood vessel segment parameters related to the blood vessel outlet are obtained; wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters;

[0178] The second function equation of the outlet kinetic energy of the blood vessel outlet is obtained based on the blood vessel segment parameters related to the blood vessel outlet, by using a function relationship between the outlet kinetic energy of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0179] Further, the first equation construction module 340 is configured to determine the flow resistance of the blood vessel segment by the following steps:

[0180] The third function equation of the flow resistance of the blood vessel segment is obtained based on the blood vessel segment parameters of the blood vessel segment, by using a function relationship between the flow resistance of the blood vessel segment and the outlet blood flow of the blood vessel segment.

[0181] Further, the flow resistance includes a first resistance term having a linear relationship with the blood flow rate and a second resistance term having a non-linear relationship with the blood flow rate.

[0182] The determination device for hemodynamic parameters provided by the embodiments of the present application obtains a medical image; extracts a target blood vessel from the medical image by using an image processing algorithm; and segments the target blood vessel into a plurality of blood vessel segments according to a preset segmentation manner; wherein the blood vessel geometric parameters of each blood vessel segment are monotonous in the blood flow direction of the blood vessel segment; for each blood vessel segment, the energy conservation equation and the mass conservation equation of each blood vessel segment are constructed according to the energy conservation law and the mass conservation law, respectively; the control equation group of the blood vessel segment is constructed based on the energy conservation equation and the mass conservation equation of the blood vessel segment; and the hemodynamic parameters of each blood vessel segment are solved by simultaneously solving the control equation groups of the plurality of blood vessel segments. In this way, by segmenting the blood vessel into blood vessel segments with monotonous blood vessel geometric parameters in the blood flow direction, the blood vessel segment hemodynamic parameters of the blood vessel segments can be more accurately calculated.

[0183] Please refer to Figure 4 , Figure 4 A structural schematic diagram of an electronic device provided by the embodiments of the present application is shown in FIG. 4. Figure 4 As shown in FIG. 4, the electronic device 400 includes a processor 410, a memory 420 and a bus 430.

[0184] The memory 420 stores machine readable instructions executable by the processor 410, when the electronic device 400 is running, the processor 410 and the memory 420 communicate through the bus 430, the machine readable instructions are executed by the processor 410, can execute the steps of the method embodiment as described above Figure 1 The steps of the method for determining the hemodynamic parameter in the method embodiment as shown can be implemented in the manner as described in the method embodiment, and details are not described herein.

[0185] The embodiment of the present application further provides a computer readable storage medium, the computer readable storage medium stores a computer program, the computer program is run by the processor, and the computer program can execute the steps of the method for determining the hemodynamic parameter in the method embodiment as shown, and details can be implemented in the manner as described in the method embodiment, and details are not described herein. Figure 1 The steps of the method for determining the hemodynamic parameter in the method embodiment as shown can be implemented in the manner as described in the method embodiment, and details are not described herein.

[0186] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein.

[0187] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, and for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some communication interface, device or unit, and can be electrical, mechanical or other forms.

[0188] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0189] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit.

[0190] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a nonvolatile computer readable storage medium executable by a processor. Based on this understanding, the technical solutions of the present application essentially or the parts of the prior art that make contributions or parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0191] Finally, it should be noted that: the above-described embodiments are only specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can make modifications or easily think of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed by the present application, or make equivalent replacements to some of the technical features. The modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of determining a hemodynamic parameter, characterized in that, The determination method comprises: acquiring medical images; extracting a target blood vessel from the medical images using an image processing algorithm; segmenting the target blood vessel into a plurality of blood vessel segments according to a preset segmentation mode; wherein the blood vessel geometric parameters of each blood vessel segment have monotonicity in the flow direction of blood in the blood vessel segment; According to the energy conservation law and the mass conservation law, an energy conservation equation and a mass conservation equation of each blood vessel segment are constructed; the energy conservation equation is constructed based on the inlet mechanical energy at the inlet of the blood vessel segment, the outlet mechanical energy at the outlet of the blood vessel segment and the mechanical energy loss caused by the blood flow in the blood vessel segment; the mass conservation equation is constructed based on the inlet blood flow of the blood vessel segment and the outlet blood flow of the blood vessel segment; the inlet mechanical energy of the blood vessel segment is determined according to the sum of the inlet kinetic energy of each blood vessel inlet and the inlet static pressure of each blood vessel inlet; the outlet mechanical energy of the blood vessel segment is determined by the sum of the outlet kinetic energy of each blood vessel outlet and the outlet static pressure of each blood vessel outlet; the mechanical energy loss of the blood vessel segment is calculated by the following formula: , is the mechanical energy loss of the blood vessel segment, is the blood flow through the blood vessel segment, is the flow resistance, is the first resistance term, is the second resistance term; , is the blood viscosity, is the length of the blood vessel segment, is the lumen profile diameter; the flow resistance includes the first resistance term having a linear relationship with the blood flow velocity and the second resistance term having a non-linear relationship with the blood flow velocity; the first resistance term is called the viscous force term; the second resistance term refers to the resistance term caused by the change of the geometric parameters, which leads to the change of the velocity distribution and the flow pattern of the blood in the lumen, thereby affecting the fluid energy loss; the change of the geometric parameters includes the narrowing or expansion of the lumen and the bending of the pipeline; the second resistance term is also related to the blood flow in the blood vessel segment; constructing a control equation set of the blood vessel segment based on the energy conservation equation and the mass conservation equation of the blood vessel segment; simultaneously solving the control equation set of the plurality of blood vessel segments to obtain the hemodynamic parameters of each blood vessel segment; wherein the hemodynamic parameters include blood flow static pressure, blood vessel segment flow, and blood flow kinetic energy; The determination method further comprises: in order to have a unique solution for the control equation set, in the target blood vessel including the complete coronary tree of the aorta, a boundary condition is applied, the boundary condition is an inlet and an outlet, and the hemodynamic parameter type is flow and flow resistance.

2. The determination method according to claim 1, characterized in that, The target blood vessel is segmented into a plurality of blood vessel segments according to a preset segmentation mode, which comprises: cutting the target blood vessel into a plurality of blood vessel segments of equal length according to a preset segmentation length; or segmenting the target blood vessel into a plurality of blood vessel segments according to a specific cutting section.

3. The determination method according to claim 1, characterized in that, For each blood vessel segment, the energy conservation equation and the mass conservation equation of each blood vessel segment are constructed according to the energy conservation law and the mass conservation law, respectively, which comprises: determining the mechanical energy loss generated when blood flows through the blood vessel segment based on the flow resistance of the blood vessel segment and the blood flow through the blood vessel segment; constructing an energy conservation equation using the inlet mechanical energy at at least one inlet of the blood vessel segment, the outlet mechanical energy at the outlet of the blood vessel segment, and the mechanical energy loss of the blood vessel segment according to the principle of energy conservation, to obtain the energy conservation equation of the blood vessel segment; constructing a mass conservation equation using the blood flow at at least one inlet of each blood vessel segment and the blood flow at at least one outlet of each blood vessel segment according to the principle of mass conservation, to obtain the mass conservation equation of the blood vessel segment.

4. The determination method according to claim 3, characterized in that, The inlet kinetic energy of each blood vessel inlet is determined by the following steps: For each blood vessel inlet, obtain the blood vessel segment parameters involved in the blood vessel inlet; wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters; obtain the first function equation of the inlet kinetic energy of the blood vessel inlet based on the blood vessel segment parameters involved in the blood vessel inlet using the functional relationship between the inlet kinetic energy of the blood vessel segment and the inlet blood flow of the blood vessel segment.

5. The determination method according to claim 3, characterized in that, The outlet kinetic energy of each blood vessel outlet is determined by the following steps: For each blood vessel outlet, obtain the blood vessel segment parameters involved in the blood vessel outlet; wherein the blood vessel segment parameters include blood vessel segment body parameters and upstream and downstream blood vessel segment geometric parameters; obtain the second function equation of the outlet kinetic energy of the blood vessel outlet based on the blood vessel segment parameters involved in the blood vessel outlet using the functional relationship between the outlet kinetic energy of the blood vessel segment and the outlet blood flow of the blood vessel segment.

6. The determination method according to claim 3, characterized in that, The flow resistance of the blood vessel segment is determined by the following steps: obtain the third function equation of the flow resistance of the blood vessel segment based on the blood vessel segment parameters of the blood vessel segment using the functional relationship between the flow resistance of the blood vessel segment and the outlet blood flow of the blood vessel segment.

7. A device for determining a hemodynamic parameter, characterized in that The determination device comprises: an image acquisition module for acquiring medical images; a blood vessel extraction module configured to extract a target blood vessel from the medical image using an image processing algorithm; a blood vessel segmentation module configured to segment the target blood vessel into a plurality of blood vessel segments according to a preset segmentation manner, wherein a blood vessel geometric parameter of each blood vessel segment has monotonicity in a blood flow direction of the blood vessel segment; a first equation construction module, configured to construct, for each blood vessel segment, an energy conservation equation and a mass conservation equation of the blood vessel segment according to the law of conservation of energy and the law of conservation of mass respectively; wherein the energy conservation equation is constructed based on an inlet mechanical energy at an inlet of the blood vessel segment, an outlet mechanical energy at an outlet of the blood vessel segment, and a mechanical energy loss caused by blood flow in the blood vessel segment; the mass conservation equation is constructed based on an inlet blood flow of the blood vessel segment and an outlet blood flow of the blood vessel segment; the inlet mechanical energy of the blood vessel segment is determined according to a sum of an inlet kinetic energy of each blood vessel inlet and an inlet static pressure of each blood vessel inlet; the outlet mechanical energy of the blood vessel segment is determined by summing up an outlet kinetic energy of each blood vessel outlet and an outlet static pressure of each blood vessel outlet; the mechanical energy loss of the blood vessel segment is calculated by the following formula: , is the mechanical energy loss of the blood vessel segment, is the blood flow through the blood vessel segment, is the flow resistance, is a first resistance term, is a second resistance term; , is the blood viscosity, is the length of the blood vessel segment, is the lumen profile diameter; the flow resistance includes a first resistance term having a linear relationship with the blood flow rate and a second resistance term having a non-linear relationship with the blood flow rate; the first resistance term is referred to as a viscous force term; the second resistance term refers to a resistance term caused by changes in geometric parameters, resulting in changes in velocity distribution and flow pattern of blood in the lumen, thereby affecting the energy loss of the fluid, the changes in geometric parameters include the narrowing or expansion of the lumen, the bending of the pipeline; the second resistance term is also related to the blood flow in the blood vessel segment; a second equation construction module configured to construct a control equation set of the blood vessel segment based on an energy conservation equation and a mass conservation equation of the blood vessel segment; a parameter determination module configured to solve a blood flow hemodynamic parameter of each blood vessel segment by simultaneously solving the control equation sets of the plurality of blood vessel segments, wherein the blood flow hemodynamic parameter comprises a blood flow static pressure, a blood vessel segment flow rate, and a blood flow kinetic energy; the determination device is further configured to apply boundary conditions of an inlet and an outlet and blood flow hemodynamic parameter blood types of a flow rate and a flow resistance in the target blood vessel of a complete coronary tree containing an aorta, so that the control equation set has a unique solution.

8. An electronic device, comprising: comprising: a processor, a memory, and a bus, the memory storing machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, the machine readable instructions are executed by the processor to perform the steps of the blood flow hemodynamic parameter determination method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, the computer readable storage medium stores a computer program, the computer program is executed by the processor to perform the steps of the blood flow hemodynamic parameter determination method according to any one of claims 1 to 6.

Images