Method, device, equipment and medium for calculating vascular status parameters

Abstract

The present disclosure provides a method, apparatus, device, and medium for calculating vascular state parameters, which can be applied to the fields of life sciences, fluid mechanics, and scientific computing. The method includes: processing the target pressure at the vascular inlet and the preset outlet pressure based on a first-type boundary condition combination to obtain the vascular inlet velocity distribution; processing the vascular inlet velocity distribution based on a second-type boundary condition combination to obtain the vascular inlet pressure, wherein the second-type boundary condition combination is used to constrain the vascular inlet velocity distribution; determining the steady-state outlet pressure based on the vascular inlet pressure and the vascular outlet resistance; processing the steady-state outlet pressure and initial vascular lumped model parameters based on a bellows model to obtain vascular state parameters, wherein the vascular state parameters include the vascular outlet pressure and the vascular lumped model parameters at t moments; and performing fluid simulation based on the vascular state parameters and the vascular inlet flow velocity at each moment to obtain the full-time, full-field fluid state.

Description

Technical Field

[0001] The present disclosure relates to the fields of life science, fluid mechanics, and scientific computing, and more specifically, to a method, apparatus, device, medium, and program product for calculating vascular state parameters. Background Art

[0002] Although traditional angiography can show the degree of stenosis of diseased blood vessels, it cannot make functional predictions about the condition. To address this issue, the blood flow reserve fraction was introduced as a functional assessment tool, and has become the gold standard for helping doctors determine whether interventional treatment is needed for coronary artery stenosis. The hospital's existing detection method requires the use of an invasive pressure guidewire to measure the pressure before and after stenosis for calculation. The accuracy of the algorithm for calculating hemodynamic parameters using fluid mechanics simulation is affected by boundary conditions. When the absolute value of the vascular outlet pressure is unknown, the assumption that the outlet pressure is 0 or other statistically derived values ​​ignores the impact of the rear-end blood vessels on the flow field caused by individual differences, and cannot accurately calculate the blood flow reserve fraction. Summary of the Invention

[0003] In view of the above problems, the present disclosure provides a method, apparatus, device, medium and program product for calculating vascular status parameters.

[0004] According to a first aspect of the present disclosure, a method for calculating a vascular state parameter is provided, comprising:

[0005] Based on the first-type boundary condition combination, the target pressure of the vascular inlet and the preset outlet pressure are processed to obtain the vascular inlet velocity distribution, and the first-type boundary condition combination is used to constrain the target pressure of the vascular inlet and the preset outlet pressure; based on the second-type boundary condition combination, the vascular inlet velocity distribution is processed to obtain the vascular inlet pressure, and the second-type boundary condition combination is used to constrain the vascular inlet velocity distribution; according to the vascular inlet pressure and the vascular outlet resistance, the steady-state outlet pressure is determined; based on the bellows model, the steady-state outlet pressure and the initial vascular lumped model parameters are processed to obtain the vascular state parameters, wherein the vascular state parameters include the vascular outlet pressure and the vascular lumped model parameters at t moments.

[0006] According to an embodiment of the present disclosure, determining the steady-state outlet resistance and pressure based on the vascular inlet pressure and flow includes: comparing the difference between the vascular inlet pressure and the vascular inlet target pressure with a preset threshold to obtain a comparison result; when the comparison result indicates that the difference is less than the preset threshold, updating the target outlet resistance based on the vascular inlet pressure and the vascular outlet resistance; and obtaining the steady-state outlet pressure based on the vascular inlet flow and the outlet resistance.

[0007] According to an embodiment of the present disclosure, the target outlet resistance and pressure are obtained according to the vascular inlet pressure and flow, including: subtracting the vascular inlet pressure of the nth step from the vascular inlet pressure of the nth step to obtain the vascular inlet pressure difference, where n>1; subtracting the vascular outlet resistance of the nth step from the vascular outlet resistance to obtain the vascular outlet resistance difference; obtaining the Jacob ratio according to the vascular inlet pressure difference and the vascular outlet resistance difference; and updating the target outlet resistance according to the Jacob ratio and the difference between the vascular inlet target pressure and the current inlet pressure.

[0008] According to an embodiment of the present disclosure, determining the steady-state outlet resistance and pressure based on the vascular inlet pressure and flow includes: comparing the difference between the vascular inlet pressure and the vascular inlet target pressure with a preset threshold to obtain a comparison result; when the comparison result indicates that the difference is greater than the preset threshold, processing the steady-state outlet pressure and the vascular inlet target pressure based on a first-type boundary condition combination to obtain a first vascular inlet velocity distribution; processing the first vascular inlet velocity distribution based on a second-type boundary condition combination to obtain a first vascular inlet pressure; and determining the first steady-state outlet pressure based on the first vascular inlet pressure and the first vascular outlet resistance.

[0009] According to an embodiment of the present disclosure, based on the bellows model and the steady-state outlet pressure, the initial vascular lumped model parameters are processed to obtain the vascular state parameters, including: determining the vascular outlet pressure at t moments based on the vascular inlet flow and the initial lumped parameters; determining the target gap based on the objective function and the outlet pressure; and updating the vascular lumped model parameters and the vascular outlet pressure at t moments based on the target gap.

[0010] According to an embodiment of the present disclosure, determining the parameters of the vascular lumped model according to the target result includes:

[0011] When the target result meets the preset conditions, the initial vascular lumped model parameters are determined as the vascular lumped model parameters; when the target result does not meet the preset conditions, the vascular lumped model parameters are updated according to the initial vascular lumped model parameters and the vascular inlet flow at time t.

[0012] According to an embodiment of the present disclosure, updating the vascular lumped model parameters based on the initial vascular lumped model parameters and the vascular inlet flow rates at t moments includes: determining a derivative matrix based on the initial vascular lumped model parameters and the vascular inlet flow rates at t moments; processing the derivative matrix based on a derivative formula to determine a sensitivity matrix; and updating the initial vascular lumped model parameters based on the sensitivity matrix, thereby updating the vascular lumped model parameters.

[0013] A second aspect of the present disclosure provides a device for calculating blood vessel status parameters, comprising:

[0014] a velocity distribution module, configured to process a target blood vessel inlet pressure and a preset outlet pressure based on a first type of boundary condition combination to obtain a blood vessel inlet velocity distribution, wherein the first type of boundary condition combination is configured to constrain the target blood vessel inlet pressure and the preset outlet pressure;

[0015] a blood vessel inlet pressure module, configured to process the blood vessel inlet velocity distribution based on a second type of boundary condition combination to obtain a blood vessel inlet pressure, wherein the second type of boundary condition combination is configured to constrain the blood vessel inlet velocity distribution;

[0016] a steady-state outlet pressure module, configured to determine a steady-state outlet pressure according to the blood vessel inlet pressure and the blood vessel outlet resistance;

[0017] The vascular state parameter module is used to process the steady-state outlet pressure and the initial vascular lumped model parameters based on the bellows model to obtain vascular state parameters, wherein the vascular state parameters include the vascular outlet pressure and the vascular lumped model parameters at t moments.

[0018] A third aspect of the present disclosure provides an electronic device, comprising: one or more processors; and a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors execute the method.

[0019] A fourth aspect of the present disclosure further provides a computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, causes the processor to execute the above method.

[0020] The fifth aspect of the present disclosure further provides a computer program product, comprising a computer program, which implements the above method when executed by a processor.

[0021] According to the embodiments of the present disclosure, the target pressure at the vascular inlet and the preset outlet pressure are processed based on a combination of first-class boundary conditions to obtain the vascular inlet velocity distribution. The vascular inlet velocity distribution is processed based on a combination of second-class boundary conditions to obtain the vascular inlet pressure. The steady-state outlet pressure is determined based on the vascular inlet pressure and the vascular outlet resistance. By alternating between the first-class boundary condition combination and the second-class boundary condition combination, the inlet velocity shape is continuously adjusted based on the current pressure differential, thereby improving overall calculation accuracy. The steady-state outlet pressure and initial vascular lumped model parameters are processed based on a bellows model to obtain vascular state parameters, thereby improving the accuracy of the outlet pressure boundary conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0023] Figure 1A diagram schematically illustrates an application scenario of a method for calculating blood vessel state parameters according to an embodiment of the present disclosure;

[0024] Figure 2 A flowchart schematically illustrates a method for calculating blood vessel state parameters according to an embodiment of the present disclosure;

[0025] Figure 3 A schematic diagram schematically illustrates a first type of boundary condition combination and a second type of boundary condition combination used according to an embodiment of the present disclosure;

[0026] Figure 4 Schematically shows a flow chart of steady-state outlet pressure according to an embodiment of the present disclosure;

[0027] Figure 5 Schematically shows a flow chart of a bellows model iterative algorithm according to an embodiment of the present disclosure;

[0028] Figure 6 A schematic diagram schematically illustrates the pressure calculation results and parameter iterative change process obtained by the bellows model iterative algorithm according to an embodiment of the present disclosure;

[0029] Figure 7 Schematically shows a flow chart of blood vessel state parameter calculation according to an embodiment of the present disclosure;

[0030] Figure 8 A flowchart schematically illustrates a method for calculating blood vessel state parameters according to an embodiment of the present disclosure;

[0031] Figure 9 A block diagram schematically illustrates a structure of a device for calculating blood vessel state parameters according to an embodiment of the present disclosure; and

[0032] Figure 10 The figure schematically shows a block diagram of an electronic device suitable for implementing a method for calculating blood vessel status parameters according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0034] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0035] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0036] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0037] Fractional Flow Reserve (FFR) is a method for quantitatively assessing the effect of coronary artery stenosis on blood flow imaging. It refers to the ratio of the maximum blood flow that can be obtained by the myocardial area supplied by a coronary artery in the presence of a stenotic lesion to the maximum blood flow that the same area can theoretically obtain under normal conditions. Specifically, it is the ratio of the mean pressure in the coronary artery distal to the stenosis (Pd) at maximum myocardial hyperemia to the mean pressure in the aorta at the coronary artery ostium (Pa). While traditional angiography can demonstrate the degree of stenosis in diseased vessels, it cannot provide functional predictions of the condition. To address this issue, the Fractional Flow Reserve (FFR) was introduced as a functional assessment tool and has become the gold standard for helping physicians determine the need for interventional treatment in coronary artery stenosis. Existing hospital testing methods require the use of an invasive pressure guidewire to measure pressure before and after stenosis for calculation.

[0038] The inventors discovered that the accuracy of the algorithm for calculating hemodynamic parameters using fluid mechanics simulation is affected by boundary conditions. When the absolute value of the outlet pressure is unknown, the assumption that the outlet pressure is 0 or other statistically derived values ​​ignores the impact of the rear-end blood vessels on the flow field caused by individual differences in the subjects, and cannot accurately calculate the blood flow reserve fraction.

[0039] In view of this, the present disclosure provides a method, device, equipment and medium for calculating vascular state parameters, the method including: processing the vascular inlet target pressure and the preset outlet pressure based on a first-type boundary condition combination to obtain the vascular inlet velocity distribution, the first-type boundary condition combination is used to constrain the vascular inlet target pressure and the preset outlet pressure; processing the vascular inlet velocity distribution based on a second-type boundary condition combination to obtain the vascular inlet pressure, the second-type boundary condition combination is used to constrain the vascular inlet velocity distribution; determining the steady-state outlet pressure based on the vascular inlet pressure and the vascular outlet resistance; processing the steady-state outlet pressure and the initial vascular lumped model parameters based on a bellows model to obtain vascular state parameters, wherein the vascular state parameters include the vascular outlet pressure and the vascular lumped model parameters at t moments.

[0040] In the technical solutions disclosed herein, the user information (including but not limited to user personal information, user image information, user device information, such as location information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved are all information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of the relevant data comply with relevant laws, regulations and standards, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0041] Figure 1 The following schematically illustrates an application scenario of the method for calculating blood vessel status parameters according to an embodiment of the present disclosure.

[0042] like Figure 1 As shown, the application scenario 100 according to this embodiment may include terminal devices 101, 102, 103, a network 104, and a server 105. The network 104 is used as a medium for providing a communication link between the terminal devices 101, 102, 103 and the server 105. The network 104 may include various connection types, such as wired or wireless communication links or optical fiber cables.

[0043] Users can use terminal devices 101, 102, and 103 to interact with server 105 via network 104 to receive or send messages, etc. Various communication client applications can be installed on terminal devices 101, 102, and 103, such as shopping applications, web browser applications, search applications, instant messaging tools, email clients, social platform software, etc. (only as examples).

[0044] The terminal devices 101 , 102 , and 103 may be various electronic devices having a display screen and supporting web browsing, including but not limited to smart phones, tablet computers, laptop computers, and desktop computers.

[0045] Server 105 may be a server that provides various services, such as a background management server (for example only) that supports websites browsed by users using terminal devices 101, 102, and 103. The background management server may analyze and process received data such as user requests, and feed back processing results (e.g., web pages, information, or data obtained or generated based on user requests) to the terminal device.

[0046] It should be noted that the method for calculating vascular state parameters provided in the embodiments of the present disclosure can generally be executed by the server 105. Accordingly, the device for calculating vascular state parameters provided in the embodiments of the present disclosure can generally be set in the server 105. The method for calculating vascular state parameters provided in the embodiments of the present disclosure can also be executed by a server or server cluster that is different from the server 105 and can communicate with the terminal devices 101, 102, 103 and / or the server 105. Accordingly, the device for calculating vascular state parameters provided in the embodiments of the present disclosure can also be set in a server or server cluster that is different from the server 105 and can communicate with the terminal devices 101, 102, 103 and / or the server 105.

[0047] It should be understood that Figure 1 The number of terminal devices, networks and servers in the embodiment is merely illustrative. Any number of terminal devices, networks and servers may be provided as required.

[0048] The following will be based on Figure 1 The scene described by Figures 2 to 8 The calculation method of the blood vessel state parameters of the disclosed embodiment is described in detail.

[0049] Figure 2 The flowchart of the method for calculating the blood vessel state parameters according to the embodiment of the present disclosure is schematically shown.

[0050] like Figure 2 As shown, the method for calculating the blood vessel state parameters of this embodiment includes operations S210 to S240.

[0051] In operation S210 , based on the first type of boundary condition combination, a blood vessel inlet velocity distribution is obtained using a blood vessel inlet target pressure and a preset outlet pressure.

[0052] In operation S220 , the blood vessel inlet velocity distribution is processed based on the second type of boundary condition combination to obtain the blood vessel inlet pressure. The second type of boundary condition combination is used to constrain the blood vessel inlet velocity distribution.

[0053] In operation S230 , a steady-state outlet pressure is determined based on the blood vessel inlet pressure and the blood vessel outlet resistance.

[0054] In operation S240 , the steady-state outlet pressure and the initial vascular lumped model parameters are processed based on the bellows model to obtain vascular state parameters, wherein the vascular state parameters include the vascular outlet pressure and the vascular lumped model parameters at t moments.

[0055] According to the embodiments of the present disclosure, the first type of boundary condition combination can obtain the inlet velocity distribution under a specific blood vessel morphology. The second type of boundary condition combination can iteratively obtain the steady-state outlet pressure under the blood vessel inlet pressure and flow constraints.

[0056] According to an embodiment of the present disclosure, the distribution shape of the inlet velocity of the blood vessel under this pressure difference condition can be obtained based on the first type of boundary condition combination according to the target pressure at the blood vessel inlet and the preset outlet pressure.

[0057] According to an embodiment of the present disclosure, based on the combination of the second type of boundary conditions with a fixed inlet velocity distribution shape, when the vascular inlet flow rate is also known, the vascular inlet pressure at this moment can be obtained through the outlet pressure model.

[0058] According to the embodiments of the present disclosure, the target pressure at the vascular inlet can be used as the optimization target, and an iterative optimization calculation process can be constructed to determine the vascular outlet resistance and steady-state outlet pressure using the vascular inlet velocity distribution, vascular inlet flow, and outlet pressure model.

[0059] According to the embodiment of the present disclosure, the outlet pressure model may adopt any model related to flow rate, and the specific type of the outlet pressure model is not limited herein.

[0060] According to an embodiment of the present disclosure, the steady-state outlet pressure can be determined based on the vascular inlet flow rate and the vascular inlet target pressure. The vascular outlet resistance can assume the initial value of the outlet resistance, and the resistance fluctuation coefficient can be set to 0.99, but is not limited to this. The embodiment of the present disclosure does not limit the specific value of the resistance fluctuation coefficient. The first outlet resistance value can be calculated based on the resistance fluctuation coefficient and the initial value of the outlet resistance. The steady-state outlet pressure can be determined based on the vascular inlet pressure, the initial value of the outlet resistance and the first outlet resistance value. The vascular outlet resistance initially needs to calculate the initial value of the outlet resistance and the first outlet resistance value, and the steady-state outlet pressure can be determined based on iteration.

[0061] According to embodiments of the present disclosure, the bellows model can utilize a commonly used transient distal vascular lumped model, such as a three-element bellows model, but is not limited thereto. Embodiments of the present disclosure do not limit the specific type of bellows model. Initial vascular lumped model parameters can be defined by empirical values. Steady-state outlet pressure and initial vascular lumped model parameters can be processed based on the bellows model to obtain vascular state parameters. These vascular state parameters can include vascular outlet pressures and vascular lumped model parameters at time t.

[0062] According to an embodiment of the present disclosure, the vascular state parameters include the vascular outlet pressure at t moments and the vascular lumped model parameters. A more accurate blood flow reserve fraction can be obtained based on the vascular outlet pressure at t moments and the vascular lumped model parameters.

[0063] Figure 3 The diagram schematically shows a first type of boundary condition combination and a second type of boundary condition combination used according to an embodiment of the present disclosure.

[0064] like Figure 3 As shown, the first boundary condition combination (i.e., boundary condition combination 1) allows adjustment of the inlet velocity shape, while the second boundary condition combination (i.e., boundary condition combination 2) allows fluid calculation at the flow inlet and pressure outlet boundaries under a specific outlet velocity shape. The velocity inlet and pressure outlet of the second boundary condition combination are programmable. The first boundary condition combination can constrain the target inlet pressure and preset outlet pressure of the vessel, thereby obtaining the inlet velocity distribution of the vessel under this pressure differential. Based on this inlet velocity distribution, the velocity in the second boundary condition combination can be determined, and the vessel inlet pressure can be calculated based on the known outlet pressure model. The vessel wall is characterized by zero pressure gradient and no slip velocity.

[0065] According to the embodiments of the present disclosure, during the steady-state iterative calculation process, the inlet velocity shape has a significant impact on the calculation of the pressure difference for blood vessels with stenosis, especially eccentric stenosis. In the algorithm proposed in this embodiment, by alternating between different boundary conditions, the inlet velocity shape is continuously adjusted according to the current pressure difference, thereby improving the overall calculation accuracy. By comparing the invasive measurement of the subject's blood pressure with the inlet velocity shape obtained using the standard parabolic inlet velocity and the inlet velocity shape obtained by alternating calculations, the pressure calculation error was reduced from over 10% to less than 1% in individual cases.

[0066] According to the embodiments of the present disclosure, the target pressure at the vascular inlet and the preset outlet pressure are processed based on a combination of first-class boundary conditions to obtain the vascular inlet velocity distribution. The vascular inlet velocity distribution is processed based on a combination of second-class boundary conditions to obtain the vascular inlet pressure. The steady-state outlet pressure is determined based on the vascular inlet pressure and the vascular outlet resistance. By alternating between the first-class boundary condition combination and the second-class boundary condition combination, the inlet velocity shape is continuously adjusted based on the current pressure differential, thereby improving overall calculation accuracy. The steady-state outlet pressure and initial vascular lumped model parameters are processed based on a bellows model to obtain vascular state parameters, thereby improving the accuracy of the outlet pressure boundary conditions.

[0067] According to an embodiment of the present disclosure, determining the steady-state outlet pressure based on the vascular inlet pressure and the vascular inlet flow rate includes: comparing the difference between the vascular inlet pressure and the vascular inlet target pressure with a preset threshold value to obtain a comparison result; when the comparison result indicates that the difference is less than the preset threshold value, updating the outlet resistance based on the vascular inlet pressure and the vascular outlet resistance; and obtaining the steady-state outlet pressure based on the vascular inlet flow rate and the outlet resistance.

[0068] According to an embodiment of the present disclosure, the target outlet resistance and pressure are obtained according to the vascular inlet pressure and flow, including: subtracting the vascular inlet pressure of the nth step from the vascular inlet pressure of the nth step to obtain the vascular inlet pressure difference, where n>1; subtracting the vascular outlet resistance of the nth step from the vascular outlet resistance to obtain the vascular outlet resistance difference; obtaining the Jacob ratio according to the vascular inlet pressure difference and the vascular outlet resistance difference; and updating the outlet resistance according to the Jacob ratio and the vascular inlet target pressure difference.

[0069] According to an embodiment of the present disclosure, the blood vessel inlet pressure at the nth step can be subtracted from the blood vessel inlet pressure at the n-1th step to obtain the blood vessel inlet pressure difference, where n>1; the blood vessel outlet resistance at the nth step can be subtracted from the blood vessel outlet resistance at the n-1th step to obtain the blood vessel outlet resistance difference; and the Jacob's ratio can be obtained based on the blood vessel inlet pressure difference and the blood vessel outlet resistance difference, as shown in formula (1).

[0070] (1)

[0071] in, represents the Jacob ratio, P represents the vascular pressure, the subscript in represents the vascular inlet, the superscript n represents the number of steps, R represents the resistance, and the subscript n represents the number of steps.

[0072] According to an embodiment of the present disclosure, the target outlet resistance can be determined according to the Jacob's ratio and the target blood vessel inlet pressure, as shown in formula (2).

[0073] (2)

[0074] Where R represents resistance, subscript n represents the number of steps, and target represents the target blood vessel pressure. Represents the Jacob's ratio.

[0075] According to the embodiment of the present disclosure, two resistance values ​​of different steps are required in formula (1), so the initial value of the outlet resistance is determined by empirical value at the beginning, and then the first outlet resistance value is determined according to the resistance fluctuation coefficient. Thus, the target outlet resistance can be calculated using formula (1) and formula (2).

[0076] According to an embodiment of the present disclosure, determining the steady-state outlet resistance and pressure based on the vascular inlet pressure and flow includes: comparing the difference between the vascular inlet pressure and the vascular inlet target pressure with a preset threshold to obtain a comparison result; when the comparison result indicates that the difference is greater than the preset threshold, processing the steady-state outlet pressure and the vascular inlet target pressure based on a first-type boundary condition combination to obtain a first vascular inlet velocity distribution; processing the first vascular inlet velocity distribution based on a second-type boundary condition combination to obtain a first vascular inlet pressure; and determining the first steady-state outlet pressure based on the first vascular inlet pressure and the first vascular outlet resistance.

[0077] According to an embodiment of the present disclosure, the difference between the vascular inlet pressure and the target vascular inlet pressure can be compared with a preset threshold to obtain a comparison result. The target vascular inlet pressure is a constant value. When the comparison result indicates that the difference is greater than the preset threshold, the steady-state outlet pressure and the target vascular inlet pressure can be processed based on a combination of first-type boundary conditions to obtain a first vascular inlet velocity distribution. The first vascular inlet velocity distribution can be processed based on a combination of second-type boundary conditions to obtain a first vascular inlet pressure. The first steady-state outlet pressure can be ultimately determined based on the first vascular inlet pressure and the first vascular outlet resistance.

[0078] Figure 4 A flow chart schematically illustrates a steady-state outlet pressure according to an embodiment of the present disclosure.

[0079] like Figure 4 As shown, the target blood vessel inlet pressure P can be obtained first. target , inlet flow measurement value Q in , assuming the initial value of the outlet resistance is R0 (i.e. S410). Based on the first type of boundary condition combination, the target pressure P of the blood vessel inlet is processed. target and preset outlet pressure Q in , and obtain the vascular inlet velocity distribution (i.e., S420). Based on the combination of the second type of boundary conditions, the vascular inlet velocity distribution is processed to obtain the vascular inlet pressure (i.e., S430). Since two iterative steps of resistance are required when calculating the Jacob ratio, a resistance fluctuation coefficient needs to be set to calculate R1 (i.e., S440). Based on the combination of the second type of boundary conditions, the vascular inlet velocity distribution is processed to obtain the vascular inlet pressure (i.e., S450). The difference between the vascular inlet pressure and the vascular inlet target pressure is compared with the preset threshold to obtain the comparison result (i.e., S460). The vascular inlet target pressure is a constant value. When the comparison result indicates that the difference is less than the preset threshold (i.e., S460), the Jacob ratio is calculated using formula (1) (i.e., S470), and then the outlet resistance is updated using the Newton-Raphson iterative method using formula (2) (i.e., S480). Finally, the vascular outlet pressure is updated using the flow rate and the updated outlet resistance (i.e., S490).

[0080] According to the embodiment of the present disclosure, when the difference in the comparison result is greater than the preset threshold, the current number of iterations needs to be increased by 1 (i.e., S4100). When the number of iterations is greater than the set value, the iteration step is terminated. When the number of iterations is less than the set value, it is necessary to re-process the updated blood vessel inlet pressure and the blood vessel inlet target pressure according to the first type of boundary conditions, and obtain a new inlet velocity distribution. Figure 4 Iterate the flowchart.

[0081] According to the embodiment of the present disclosure, a pure resistance outlet boundary model is adopted in this embodiment, and the blood vessel outlet pressure is specified to be proportional to the first power of the flow rate. The initial value of the resistance is assumed to make the calculated value of the blood vessel outlet pressure close to 70% of the inlet pressure. Thereafter, the resistance is manually reduced to 99% of the initial estimated value to obtain pressure fluctuations, and the inlet pressure and resistance values ​​at two moments are obtained to meet the calculation needs of the subsequent iterative process. Finally, the outlet pressure value is updated according to the given iterative method. When performing fluid calculations, the blood adopts a non-Newtonian fluid laminar flow model. The iterative process is achieved by adding calculation, update and control codes to the outer layer of the SIMPLE algorithm under the OpenFoam architecture.

[0082] According to the embodiments of the present disclosure, a steady-state iterative algorithm is used to calculate the absolute value of the outlet pressure of the responsible vessel segment non-invasively, given the known flow rate, inlet pressure, and outlet pressure models. Existing commonly used methods for calculating human vascular hemodynamics use zero outlet pressure or fixed outlet pressure, which cannot obtain the patient's own personalized absolute pressure value, cannot effectively estimate the solid stress on the vessel wall, and cannot accurately calculate the blood flow reserve fraction. The algorithm proposed in this disclosure provides a way to accurately calculate the blood flow reserve fraction and also provides a basis for fluid-solid coupling calculations and vessel wall stress analysis.

[0083] According to an embodiment of the present disclosure, the steady-state outlet pressure and the initial vascular lumped model parameters are processed based on the bellows model to obtain the vascular state parameters, including: determining the vascular outlet pressure at t moments based on the vascular inlet flow; processing the steady-state outlet pressure value based on the objective function to determine the target result, wherein the objective function is determined based on the bellows model; determining the vascular lumped model parameters based on the target result, wherein the vascular state parameters include the vascular outlet pressure at t moments and the vascular lumped model parameters.

[0084] According to an embodiment of the present disclosure, the blood vessel outlet pressure at time t can be determined based on the blood vessel inlet flow and the steady-state outlet pressure, as shown in formula (3).

[0085] (3)

[0086] in, represents the vascular outlet pressure at time t, represents the blood vessel inlet flow rate, Rs and Rd represent the resistance in the bellows model, and C represents the capacitance in the bellows model.

[0087] According to an embodiment of the present disclosure, the objective function is determined based on a bellows model. For example, the bellows model is a three-element bellows model. This model, exemplified by a series resistor, a parallel resistor, and a capacitor, can simultaneously simulate the effects of both the end-of-line resistance and the elasticity of the vascular network on the hemodynamic state. The differential equation describing this circuit system (i.e., the governing equation N) is shown in Equation (4).

[0088] (4)

[0089] in, represents pressure, Rs and Rd represent resistance in the bellows model, C represents capacitance in the bellows model, represents the blood vessel inlet flow rate, represents the tth moment.

[0090] In order to obtain the values ​​of the circuit parameters C, Rd, and Rs in formula (4), an optimization problem for the above differential equation is constructed, as shown in formula (5).

[0091] (5)

[0092] in, To minimize, L is the objective function, u represents the state variable, that is, the pressure at each moment, express .

[0093] According to an embodiment of the present disclosure, the steady-state outlet pressure value may be processed based on the objective function to determine the target result, as shown in formula (6).

[0094] |L ref -L | = | P out_sys , P out_dia , P out_mid |-|P max , P min , P mid | T (6)

[0095] Among them, L ref represents the objective function of the circuit system, P out_sys , P out_dia , P out_mid They represent the maximum pressure, minimum pressure, and average pressure calculated from the current state of the circuit system, respectively. max , P min , P midThey respectively represent the maximum pressure, minimum pressure and average pressure obtained during the calculation of the steady-state outlet pressure.

[0096] According to an embodiment of the present disclosure, blood vessel lumped model parameters may be determined based on target results.

[0097] Figure 5 The flowchart of the bellows model iterative algorithm according to an embodiment of the present disclosure is schematically shown.

[0098] like Figure 5 Figure A shows the inlet velocity distribution using a standard elliptical inlet; Figure B shows the evolution of the three values ​​for the elliptical inlet velocity; Figure C shows the flow field streamlines when the inlet pressure meets the conditions; Figure D shows the inlet velocity distribution obtained using the first type of boundary condition combination; Figure E shows the parameter value evolution during the iteration using the second type of boundary condition combination; Figure F shows the flow field streamlines when the vascular inlet meets the pressure conditions. By modifying the inlet shape, the error between the calculated pressure and the measured pressure was reduced from 3.2481% to 0.3008%.

[0099] Figure 6 A schematic diagram schematically shows the pressure calculation results and parameter iterative change process obtained by the bellows model iterative algorithm according to an embodiment of the present disclosure.

[0100] like Figure 6 As shown, Figure A is the calculation result of the responsible blood vessel pressure field at the diastolic pressure moment; Figure B is the calculation result of the responsible blood vessel pressure field at the systolic pressure moment; Figure C is the change process of the three lumped parameters during the iteration process; Figure D is the outlet pressure waveform obtained after the bellows model iteration is completed and the pressure relationship between the three control points.

[0101] According to an embodiment of the present disclosure, determining the parameters of the vascular lumped model according to the target result includes:

[0102] When the target result meets the preset conditions, the initial vascular lumped model parameters are determined as the vascular lumped model parameters; when the target result does not meet the preset conditions, the vascular lumped model parameters are determined based on the initial vascular lumped model parameters and the vascular outlet pressure at time t.

[0103] According to an embodiment of the present disclosure, in the target result (ie L ref When the value of L meets the preset conditions, for example, when the target result is less than a certain value, the initial vascular lumped model parameters can be determined as the vascular lumped model parameters.

[0104] According to an embodiment of the present disclosure, when the target result does not meet the preset conditions, for example, when the target result is greater than a certain value, the vascular lumped model parameters can be updated based on the initial vascular lumped model parameters and the vascular inlet flow at t moments.

[0105] According to an embodiment of the present disclosure, the vascular lumped model parameters are updated based on the initial vascular lumped model parameters and the vascular inlet flow at t moments, including: determining a derivative matrix based on the initial vascular lumped model parameters, the vascular flow at t moments, and the differential format of the bellows model; processing the derivative matrix based on the derivative formula to determine the sensitivity matrix; and updating the initial vascular lumped model parameters based on the sensitivity matrix to determine the vascular lumped model parameters.

[0106] According to an embodiment of the present disclosure, a derivative matrix can be determined based on the initial vascular lumped model parameters, the vascular inlet flow rates at t moments, and the differential format of the bellows model. The vascular inlet flow rates can be detected in real time. The partial derivative of the objective function L with respect to the state variable u (i.e., the pressure at each moment) is shown in Equation (7).

[0107] (7)

[0108] The matrix size is m × 3, where m is the number of blood pressure points recorded during one cardiac cycle. Each row has only one entry set to 1. The first row of entries with a size of 1 corresponds to the time point of maximum blood pressure, the second row corresponds to the time point of minimum blood pressure, and the third row corresponds to the mean.

[0109] According to an embodiment of the present disclosure, the derivative of the partial derivative of the state variable u with respect to the control equation N is shown in formula (8).

[0110] (8)

[0111] Among them, the matrix size is m×m, , , Rd represents the resistance in the bellows model, C represents the capacitance in the bellows model, represents the tth moment.

[0112] According to an embodiment of the present disclosure, the partial derivative matrix form of the control equation N with respect to the design variable φ is shown in formula (9).

[0113] (9)

[0114] in,

[0115] (10)

[0116] (11)

[0117] (12)

[0118] in, represents pressure, Rs and Rd represent resistance in the bellows model, C represents capacitance in the bellows model, represents the blood vessel inlet flow rate, represents the tth moment.

[0119] According to an embodiment of the present disclosure, the derivative matrix can be processed based on the derivative formula to determine the sensitivity matrix, as shown in formula (13).

[0120] (13)

[0121] in, represents the sensitivity matrix, represents the objective function, represents the state variable, N represents the control equation, and φ represents the design variable.

[0122] According to the embodiment of the present disclosure, the initial vascular lumped model parameters can be updated based on the sensitivity matrix to determine the vascular lumped model parameters. The second term after the equal sign in formula (10) is set to zero in the first and second steps. After the third step, this term is directly calculated based on the state of the previous two time points. This optimization problem calculation process calculates the pressure value at each time point within a cardiac cycle. The required input is the flow rate and the pressure at three moments (i.e., the maximum pressure moment, the minimum pressure moment, and the average pressure moment) within the cardiac cycle as control variables. During the calculation process, the periodic assumption of flow rate and pressure can be used to perform multiple cycle calculations using formula (3), and the calculation cycle result with stable results within a cycle is taken as the result of the forward calculation.

[0123] According to an embodiment of the present disclosure, the outlet pressure sequence is completed and vascular lumped model parameters After iterative calculation, the pressure sequence can be used as the outlet pressure boundary condition of the responsible vascular segment to perform transient fluid dynamics calculations, obtain the full flow field pressure and velocity conditions at all time points in a cardiac cycle, and perform post-processing parameter calculations as needed.

[0124] According to the embodiments of the present disclosure, in existing human vascular hemodynamic simulations, the parameters in the lumped parameter model that considers the impact of downstream blood vessels on outlet pressure are mostly based on statistical average values, which cannot take into account the specificity of the patient's own vascular system. The vascular state parameter iteration method proposed in the present disclosure provides an optimization algorithm based on the target pressure at the inlet of the target blood vessel as a reference to obtain three parameters of specific downstream blood vessel characteristics (i.e., ), improves the accuracy of outlet pressure boundary conditions and provides a quantitative benchmark for clinical diagnosis and prognosis prediction. By controlling the pressure at three inlets and non-invasively measuring blood flow, the pressure and velocity fields of the blood vessels throughout the entire cardiac cycle are acquired, providing a basis for calculating parameters such as average wall shear force and oscillatory shear coefficient based on the flow field over a cardiac cycle.

[0125] Figure 7 The flowchart of the blood vessel state parameter calculation according to the embodiment of the present disclosure is schematically shown.

[0126] like Figure 7 As shown, first give the initial value of the state variable matrix φ0 (i.e. The initial value of the target function L is used to calculate the pressure value at each time point in a cardiac cycle (i.e., formula (3)). The target function L is calculated, and then the steady-state outlet pressure value is processed based on the target function to determine the target result (i.e., S740). When the target result is less than the set value, the calculated vascular lumped model parameters and the vascular outlet pressure at t moments can be used to determine the vascular lumped model parameters (i.e., S780). When the target result is greater than the set value, the derivative matrix can be calculated using formulas (5)-(10), and the sensitivity matrix can be calculated using formula (11). Finally, the state variable matrix is ​​updated to obtain the one that meets the conditions. (i.e. S770).

[0127] Figure 8 The flowchart of the method for calculating the blood vessel state parameters according to the embodiment of the present disclosure is schematically shown.

[0128] like Figure 8 As shown, first, the object blood vessel image, blood flow measurement value and blood vessel inlet target pressure are obtained (i.e. S810), and then pre-processing is performed, which includes blood vessel image segmentation and gridding (i.e. S820). The Hessian matrix enhancement plus wavefront collision plus baseline measurement algorithm can be used to complete the blood vessel image segmentation, and the open source tool Gmsh can be used to complete the gridding algorithm. Then, the steady-state pressure iteration algorithm (i.e. Figure 4 ) calculates the outlet pressure (i.e. S830), and finally uses the bellows model iterative algorithm (i.e. Figure 7 ) calculates the periodic outlet pressure sequence (i.e., the vascular outlet pressure at t moments) and performs transient fluid dynamics calculations of the responsible vascular segment (i.e., S840). Figure 4 and Figure 7 Two fluid solving algorithms including iterative algorithms are developed and implemented in the OpenFoam framework.

[0129] According to the embodiment of the present disclosure, by Figure 4 and Figure 7The combination of two iterative optimization algorithms improves the accuracy of flow field calculation in stenotic blood vessels. At the same time, through the optimization algorithm in this calculation process, three parameters that can reflect the vascular status of the rear end of the subject's own responsible blood vessels are obtained, providing a new scientific basis for clinical diagnosis and prognosis prediction.

[0130] Based on the above-mentioned method for calculating blood vessel state parameters, the present disclosure also provides a device for calculating blood vessel state parameters. Figure 9 The device is described in detail.

[0131] Figure 9 The figure schematically shows a structural block diagram of a device for calculating blood vessel state parameters according to an embodiment of the present disclosure.

[0132] like Figure 9 As shown, the blood vessel state parameter calculation device 900 of this embodiment includes a velocity distribution module 910 , a blood vessel inlet pressure module 920 , a steady-state outlet pressure module 930 and a blood vessel state parameter module 940 .

[0133] a velocity distribution module, configured to process a target blood vessel inlet pressure and a preset outlet pressure based on a first type of boundary condition combination to obtain a blood vessel inlet velocity distribution, wherein the first type of boundary condition combination is configured to constrain the target blood vessel inlet pressure and the preset outlet pressure;

[0134] a blood vessel inlet pressure module, configured to process the blood vessel inlet velocity distribution based on a second type of boundary condition combination to obtain a blood vessel inlet pressure, wherein the second type of boundary condition combination is configured to constrain the blood vessel inlet velocity distribution;

[0135] a steady-state outlet pressure module, configured to determine a steady-state outlet pressure according to the blood vessel inlet pressure and the blood vessel outlet resistance;

[0136] The vascular state parameter module is used to process the steady-state outlet pressure and the initial vascular lumped model parameters based on the bellows model to obtain vascular state parameters, wherein the vascular state parameters include the vascular outlet pressure and the vascular lumped model parameters at t moments.

[0137] According to the embodiments of the present disclosure, the target pressure at the vascular inlet and the preset outlet pressure are processed based on a combination of first-class boundary conditions to obtain the vascular inlet velocity distribution. The vascular inlet velocity distribution is processed based on a combination of second-class boundary conditions to obtain the vascular inlet pressure. The steady-state outlet pressure is determined based on the vascular inlet pressure and the vascular outlet resistance. By alternating between the first-class boundary condition combination and the second-class boundary condition combination, the inlet velocity shape is continuously adjusted based on the current pressure differential, thereby improving overall calculation accuracy. The steady-state outlet pressure and initial vascular lumped model parameters are processed based on a bellows model to obtain vascular state parameters, thereby improving the accuracy of the outlet pressure boundary conditions.

[0138] According to an embodiment of the present disclosure, the steady-state outlet pressure module includes: a comparison result unit, a target outlet resistance unit, and a steady-state outlet pressure unit.

[0139] The comparison result unit is used to compare the difference between the blood vessel inlet pressure and the blood vessel inlet target pressure with a preset threshold value to obtain a comparison result.

[0140] The target outlet resistance unit is used to obtain the target outlet resistance according to the blood vessel inlet pressure and the blood vessel outlet resistance when the difference represented by the comparison result is less than a preset threshold.

[0141] The steady-state outlet pressure unit is used to obtain the steady-state outlet pressure according to the blood vessel inlet flow rate and the target outlet resistance.

[0142] According to an embodiment of the present disclosure, the target outlet resistance unit includes: an inlet pressure difference subunit, an outlet resistance difference subunit, a Jacobi value obtaining subunit and a target outlet resistance subunit.

[0143] The inlet pressure difference subunit is used to subtract the inlet pressure of the (n-1)th blood vessel from the inlet pressure of the nth blood vessel to obtain the blood vessel inlet pressure difference, where n>1.

[0144] The outlet resistance difference subunit is used to subtract the outlet resistance of the (n-1)th blood vessel from the outlet resistance of the nth blood vessel to obtain the blood vessel outlet resistance difference.

[0145] The Jacobi value obtaining subunit is used to obtain the Jacobi value according to the blood vessel inlet pressure difference and the blood vessel outlet resistance difference.

[0146] The target outlet resistance subunit is used to determine the target outlet resistance according to the Jacob ratio value and the target pressure at the blood vessel inlet.

[0147] According to an embodiment of the present disclosure, the steady-state outlet pressure module includes: a first comparison result unit, a first velocity distribution unit, a first blood vessel inlet pressure unit, and a first steady-state outlet pressure unit.

[0148] The first comparison result unit is used to compare the difference between the blood vessel inlet pressure and the blood vessel inlet target pressure with a preset threshold value to obtain a comparison result.

[0149] The first velocity distribution unit is used to process the steady-state outlet pressure and the blood vessel inlet target pressure based on the first type of boundary conditions when the difference in the comparison result is greater than a preset threshold, so as to obtain a first blood vessel inlet velocity distribution.

[0150] The first blood vessel inlet pressure unit is used to process the first blood vessel inlet velocity distribution based on the second type of boundary conditions to obtain the first blood vessel inlet pressure.

[0151] The first steady-state outlet pressure unit is used to determine the first steady-state outlet pressure according to the first blood vessel inlet pressure and the first blood vessel outlet resistance.

[0152] According to an embodiment of the present disclosure, the vascular state parameter module includes: a vascular outlet pressure submodule, a target result submodule, and a vascular lumped model parameter submodule.

[0153] The vascular outlet pressure submodule is used to determine the vascular outlet pressure at time t based on the vascular inlet flow and steady-state outlet pressure.

[0154] The target result submodule is used to process the steady-state outlet pressure value based on the target function and determine the target result, wherein the target function is determined based on the bellows model.

[0155] The vascular lumped model parameter submodule is used to determine the vascular lumped model parameters according to the target results, wherein the vascular state parameters include the vascular outlet pressure at time t and the vascular lumped model parameters.

[0156] According to an embodiment of the present disclosure, the blood vessel lumped model parameter submodule includes: a first determination unit and a second determination unit.

[0157] a first determining unit, configured to determine the initial vascular lumped model parameters as the vascular lumped model parameters if the target result satisfies a preset condition;

[0158] The second determining unit is configured to update the vascular lumped model parameters according to the initial vascular lumped model parameters and the vascular inlet flow rates at t moments when the target result does not meet the preset conditions.

[0159] According to an embodiment of the present disclosure, the second determination unit includes: a derivative matrix determination subunit, a sensitivity matrix determination subunit, and a blood vessel lumped model parameter determination subunit.

[0160] The derivative matrix determination subunit is used to determine the derivative matrix according to the initial blood vessel lumped model parameters and the blood vessel inlet flow at t moments.

[0161] The sensitivity matrix determination subunit is used to process the derivative matrix based on the derivative formula and determine the sensitivity matrix.

[0162] The vascular lumped model parameter determination subunit is used to update the initial vascular lumped model parameters according to the sensitivity matrix and update the vascular lumped model parameters.

[0163] According to embodiments of the present disclosure, any multiple modules among the velocity distribution module 910, the vascular inlet pressure module 920, the steady-state outlet pressure module 930, and the vascular state parameter module 940 can be combined into a single module, or any one of these modules can be split into multiple modules. Alternatively, at least part of the functionality of one or more of these modules can be combined with at least part of the functionality of other modules and implemented in a single module. According to embodiments of the present disclosure, at least one of the velocity distribution module 910, the vascular inlet pressure module 920, the steady-state outlet pressure module 930, and the vascular state parameter module 940 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application-specific integrated circuit (ASIC), or can be implemented in hardware or firmware by any other reasonable means of circuit integration or packaging, or can be implemented in any one of the three implementation methods of software, hardware, and firmware, or any appropriate combination of any of these. Alternatively, at least one of the velocity distribution module 910, the blood vessel inlet pressure module 920, the steady-state outlet pressure module 930, and the blood vessel state parameter module 940 may be at least partially implemented as a computer program module, which may perform corresponding functions when executed.

[0164] Figure 10 The figure schematically shows a block diagram of an electronic device suitable for implementing a method for calculating blood vessel status parameters according to an embodiment of the present disclosure.

[0165] like Figure 10 As shown, the electronic device 1000 according to an embodiment of the present disclosure includes a processor 1001, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage portion 1008 into a random access memory (RAM) 1003. The processor 1001 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1001 may also include onboard memory for caching purposes. The processor 1001 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0166] Various programs and data required for the operation of the electronic device 1000 are stored in the RAM 1003. The processor 1001, the ROM 1002, and the RAM 1003 are connected to each other via a bus 1004. The processor 1001 performs various operations of the method flow according to the embodiment of the present disclosure by executing the programs in the ROM 1002 and / or the RAM 1003. It should be noted that the programs may also be stored in one or more memories other than the ROM 1002 and the RAM 1003. The processor 1001 may also perform various operations of the method flow according to the embodiment of the present disclosure by executing the programs stored in the one or more memories.

[0167] According to an embodiment of the present disclosure, electronic device 1000 may further include an input / output (I / O) interface 1005, which is also connected to bus 1004. Electronic device 1000 may also include one or more of the following components connected to I / O interface 1005: an input section 1006 including a keyboard, mouse, etc.; an output section 1007 including devices such as a cathode ray tube (CRT), liquid crystal display (LCD), and speakers; a storage section 1008 including a hard disk; and a communication section 1009 including a network interface card such as a LAN card or modem. Communication section 1009 performs communication processing via a network such as the Internet. A drive 1010 is also connected to I / O interface 1005 as needed. Removable media 1011, such as a magnetic disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed in drive 1010 as needed, so that computer programs read from the removable media can be installed into storage section 1008 as needed.

[0168] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments, or may exist independently and not be incorporated into the device / apparatus / system. The computer-readable storage medium carries one or more programs, and when executed, implements the method according to the embodiments of the present disclosure.

[0169] According to an embodiment of the present disclosure, a computer-readable storage medium may be a non-volatile computer-readable storage medium, and may include, for example, but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to an embodiment of the present disclosure, a computer-readable storage medium may include the ROM 1002 and / or RAM 1003 described above, and / or one or more memories other than ROM 1002 and RAM 1003.

[0170] The present disclosure also includes a computer program product comprising a computer program containing program code for executing the method shown in the flowchart. When the computer program product is executed in a computer system, the program code is used to cause the computer system to implement the method for calculating vascular status parameters provided in the present disclosure.

[0171] The computer program executes the above functions defined in the system / device of the embodiment of the present disclosure when the processor 1001 executes the computer program. According to the embodiment of the present disclosure, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0172] In one embodiment, the computer program may be stored on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may be transmitted and distributed in the form of a signal on a network medium, downloaded and installed via the communication portion 1009, and / or installed from the removable medium 1011. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0173] In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 1009, and / or installed from the removable medium 1011. When the computer program is executed by the processor 1001, the above-described functions defined in the system of the embodiment of the present disclosure are performed. According to the embodiment of the present disclosure, the systems, devices, means, modules, units, etc. described above can be implemented by computer program modules.

[0174] According to an embodiment of the present disclosure, the program code for executing the computer program provided by the embodiment of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computer programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C" or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect via the Internet).

[0175] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the above-mentioned module, program segment, or a part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0176] Those skilled in the art will appreciate that the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in various ways, even if such combinations and / or couplings are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or couplings are intended to fall within the scope of this disclosure.

[0177] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for calculating vascular status parameters, characterized in that: The method comprises: Processing a target blood vessel inlet pressure and a preset outlet pressure based on a first-type boundary condition combination to obtain a blood vessel inlet velocity distribution, wherein the first-type boundary condition combination is used to constrain the target blood vessel inlet pressure and the preset outlet pressure; processing the blood vessel inlet velocity distribution based on a second type of boundary condition combination to obtain a blood vessel inlet pressure, wherein the second type of boundary condition combination is used to constrain the blood vessel inlet velocity distribution; Comparing the difference between the blood vessel inlet pressure and the blood vessel inlet target pressure with a preset threshold value to obtain a comparison result; If the comparison result indicates that the difference is less than the preset threshold, subtract the blood vessel inlet pressure at step (n-1) from the blood vessel inlet pressure at step (n) to obtain the blood vessel inlet pressure difference, where n>1; Subtract the vascular outlet resistance at step n from the vascular outlet resistance at step n-1 to obtain the vascular outlet resistance difference; Obtaining a Jacob's ratio according to the blood vessel inlet pressure difference and the blood vessel outlet resistance difference; updating the target outlet resistance according to the Jacob ratio value, the target blood vessel inlet pressure, and the current inlet pressure; Obtaining a steady-state outlet pressure according to the blood vessel inlet flow rate and the target outlet resistance; The steady-state outlet pressure, inlet flow sequence and initial vascular lumped model parameters are processed based on the bellows model to obtain vascular state parameters, wherein the vascular state parameters include vascular outlet pressure and vascular lumped model parameters at t moments.

2. The method according to claim 1, characterized in that Determining the steady-state outlet pressure according to the blood vessel inlet pressure and the blood vessel outlet resistance includes: Comparing the difference between the blood vessel inlet pressure and the blood vessel inlet target pressure with a preset threshold value to obtain a comparison result; When the comparison result indicates that the difference is greater than the preset threshold, combining and processing the steady-state outlet pressure and the target blood vessel inlet pressure based on the first type of boundary conditions to obtain a first blood vessel inlet velocity distribution; Processing the first blood vessel inlet velocity distribution based on the second type of boundary conditions to obtain the first blood vessel inlet pressure; A first steady-state outlet pressure is determined according to the first blood vessel inlet pressure and the first blood vessel outlet resistance.

3. The method according to claim 1, characterized in that The steady-state outlet pressure and the initial vascular lumped model parameters are processed based on the bellows model to obtain vascular state parameters, including: Determining the blood vessel outlet pressure at the time t according to the blood vessel inlet flow rate and the target pressure; processing the outlet pressure value at a specific moment in a steady state based on the objective function to determine a target result, wherein the outlet pressure at the specific moment is determined based on bellows model parameters and blood vessel inlet flow; According to the target result, the blood vessel lumped model parameters and the blood vessel outlet pressure at time t are determined.

4. The method according to claim 3, characterized in that Determining the blood vessel lumped model parameters according to the target result includes: In a case where the target result meets a preset condition, determining the blood vessel lumped model parameters as target blood vessel lumped model parameters; When the target result does not meet the preset conditions, the vascular lumped model parameters are updated according to the initial vascular lumped model parameters and the vascular inlet flow rates at t moments.

5. The method according to claim 4, characterized in that The updating of the vascular lumped model parameters according to the initial vascular lumped model parameters and the vascular inlet flow rates at time t includes: Determining a derivative matrix according to the initial blood vessel lumped model parameters and the blood vessel inlet flow rates at the t moments; Processing the derivative matrix based on a derivative formula to determine a sensitivity matrix; The initial blood vessel lumped model parameters are updated according to the sensitivity matrix, and the blood vessel lumped model parameters are updated.

6. A device for calculating blood vessel status parameters, characterized in that: The device comprises: a velocity distribution module, configured to process a target blood vessel inlet pressure and a preset outlet pressure based on a first type of boundary condition combination to obtain a blood vessel inlet velocity distribution, wherein the first type of boundary condition combination is configured to constrain the target blood vessel inlet pressure and the preset outlet pressure; a blood vessel inlet pressure module, configured to process the blood vessel inlet velocity distribution based on a second type of boundary condition combination to obtain a blood vessel inlet pressure, wherein the second type of boundary condition combination is configured to constrain the blood vessel inlet velocity distribution; a steady-state outlet pressure module, configured to determine a steady-state outlet pressure according to the blood vessel inlet pressure and the blood vessel outlet resistance; A vascular state parameter module is used to process the steady-state outlet pressure and the initial vascular lumped model parameters based on a bellows model to obtain vascular state parameters, wherein the vascular state parameters include the vascular outlet pressure and the vascular lumped model parameters at t moments, and the vascular state parameter calculation device is used to execute the method according to any one of claims 1 to 5.

7. An electronic device comprising: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors are enabled to execute the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, causes the processor to perform the method according to any one of claims 1 to 5.

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