Intracranial aneurysm in-vitro amplification model blood circulation experiment system and method

Abstract

The invention relates to an intracranial aneurysm in-vitro amplification model blood circulation experiment system and method, and the system comprises an intracranial aneurysm in-vitro amplification model, a peristaltic pump, a liquid storage tank, a flow detection part and a pressure detection part, one end of the pump pipe is connected with an outlet of the liquid storage tank, the other end of the pump pipe is connected with an inlet of the intracranial aneurysm in-vitro amplification model, and an outlet of the intracranial aneurysm in-vitro amplification model is connected with an inlet of the liquid storage tank to form an extracorporeal circulation path. The experimental method comprises the steps of model and boundary condition zooming, blood flow simulation system construction, in-vitro patient specificity model and circulation path establishment, real-time monitoring and data acquisition. On the premise of meeting a flow similarity criterion, amplification construction of a patient specific aneurysm model, accurate simulation of physiological pulsating blood flow and systematic monitoring of key hemodynamic parameters can be realized; therefore, an in-vitro experiment platform which is more reliable and closer to the physiological state is provided for hemodynamic research of intracranial aneurysm.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of medicine and fluid mechanics, and in particular relates to an experimental system and method for an in vitro magnification model of blood flow circulation in an intracranial aneurysm. Background Technology

[0002] Intracranial aneurysms are saccular, abnormal protrusions of cerebral arteries. Their rupture is a major cause of subarachnoid hemorrhage, with extremely high mortality and disability rates. Studying the hemodynamic characteristics of aneurysms is crucial for understanding their formation, growth, and rupture mechanisms. Currently, numerical simulation and in vitro model experiments are the two main methods for studying hemodynamics. Numerical simulation offers advantages such as flexibility and lower cost, but its results depend on the accuracy of boundary conditions and the computational model, and it is difficult to visually represent flow details and perform multi-parameter coupling verification. In vitro model experiments can more realistically simulate the physiological flow environment, providing intuitive and reliable flow field and pressure data, and are an important method for validating numerical simulation results and studying the interaction between blood flow and the aneurysm wall.

[0003] However, the following technical challenges remain in in vitro model experimental research: First, the actual size of intracranial aneurysms is extremely small, making it very difficult to directly construct in vitro models and conduct precise flow field observation and measurement; second, most existing in vitro model experiments fail to consider the proportional relationship between the actual aneurysm and the model aneurysm, and often fail to take into account the principle of flow similarity when constructing the blood circulation system, resulting in deviations in the dynamic characteristics between the model flow field and the actual physiological flow field, affecting the reliability and extrapolation of experimental results; third, existing blood flow simulation devices mostly use constant flow pumps, which are difficult to accurately reproduce the physiological pulsating waveforms of blood flow velocity and pressure during the cardiac cycle, limiting their ability to simulate the real blood flow dynamic environment; in addition, the integration of complete in vitro experimental systems is not high, and there is a lack of systematic solutions in areas such as personalized model fabrication, circulatory pathway pressure regulation, and multi-parameter synchronous real-time monitoring. Summary of the Invention

[0004] The present invention addresses the problems existing in the prior art. Specifically, the technical problem to be solved by the present invention is to provide an experimental system and method for an in vitro amplification model of intracranial aneurysm blood flow circulation, which is reasonably designed and provides a reliable and reproducible in vitro experimental platform for the study of the blood flow mechanism of intracranial aneurysm.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: an experimental system for blood circulation in an extracorporeal magnification model of an intracranial aneurysm, comprising an extracorporeal magnification model of an intracranial aneurysm, a peristaltic pump, a reservoir, a flow detection device, and a pressure detection device. The reservoir stores blood-simulated liquid. The peristaltic pump is connected to a pump tube, one end of which is connected to the outlet of the reservoir and the other end of which is connected to the inlet of the extracorporeal magnification model of the intracranial aneurysm. The outlet of the extracorporeal magnification model of the intracranial aneurysm is connected to the inlet of the reservoir, forming an extracorporeal circulation pathway. The flow detection device is disposed at different arteries of the extracorporeal magnification model of the intracranial aneurysm. The pressure detection device is disposed at the top of the aneurysm of the extracorporeal magnification model of the intracranial aneurysm.

[0006] Furthermore, the blood-simulating fluid is an aqueous solution of glycerol.

[0007] Furthermore, the peristaltic pump is driven by a stepper motor, which is electrically connected to the control unit via a driver. The control unit generates a frequency-adjustable pulse signal corresponding to the cardiac cycle based on a trapezoidal acceleration / deceleration algorithm and drives the stepper motor to operate.

[0008] Furthermore, it also includes a host computer, which is electrically connected to the flow detection device and the pressure detection device respectively.

[0009] Furthermore, the liquid level in the storage tank is adjustable.

[0010] Furthermore, the in vitro magnified model of the intracranial aneurysm is obtained by 3D printing using soft rubber material based on CT image data of clinical patients.

[0011] Another technical solution adopted in this invention is: a method for experimental blood flow circulation in an in vitro magnification model of an intracranial aneurysm, comprising the following steps:

[0012] S1. Model and Boundary Condition Scaling: During in vitro modeling, the geometric dimensions of the actual intracranial aneurysm are scaled up proportionally to obtain an in vitro magnified model of the intracranial aneurysm. Based on the model magnification factor and the principle of flow similarity, the blood flow velocity, pressure and blood flow cycle are scaled up to ensure that the flow field characteristics of the in vitro magnified model of the intracranial aneurysm meet the flow similarity criteria with the actual aneurysm.

[0013] S2. Blood flow simulation system construction: The peristaltic pump driven by the stepper motor is controlled by the control unit to simulate the scaled periodic blood flow changes and reproduce the frequency, waveform, flow rate and blood pressure parameters of the cardiac cycle.

[0014] S3. Establishment of in vitro patient-specific models and circulatory pathways: Connect the in vitro magnified model of intracranial aneurysm to the reservoir to form a closed blood circulation pathway;

[0015] S4. Real-time monitoring and data acquisition: Install flow and pressure sensors in the circulation path to collect and record flow rate and pressure data in real time during the experiment.

[0016] Furthermore, the specific similarity criteria in step S1 are as follows:

[0017] S11, Geometric Similarity

[0018] Geometric similarity requires that the one-dimensional parameters of the in vitro magnified model of the intracranial aneurysm be proportional to those of the aneurysm prototype, expressed as:

[0019]

[0020] in, For one-dimensional parameters, The scale factor is m, and the subscripts m and p are the external magnification model and the prototype aneurysm of the intracranial aneurysm, respectively.

[0021] S12, Reynolds number similarity

[0022] Reynolds number similarity requires that the ratio of inertial force to viscous force in the external magnification model and the prototype flow field of an intracranial aneurysm be equal, and its expression is:

[0023]

[0024] in, For fluid density, For fluid velocity, Dynamic viscosity;

[0025] S13, Euler number similarity

[0026] Euler number similarity requires that the ratio of inertial force to pressure in the external magnification model of an intracranial aneurysm be equal to that in the prototype flow field. The expression for this is:

[0027]

[0028] in, For pressure;

[0029] S14, similar to Wormersley number

[0030] The Wormsley number similarity requirement dictates that the ratio of unsteady inertial forces and pressures in the external magnification model of an intracranial aneurysm must be equal to the ratio in the prototype flow field. Its expression is:

[0031]

[0032] in, ω is the angular frequency of the pulsation.

[0033] Furthermore, the density and dynamic viscosity of the fluid in the in vitro magnification model of intracranial aneurysm were set to be the same as those in the actual flow field, i.e. , Based on the above similarity criteria, the proportional relationship between the external magnification model and the prototype of an intracranial aneurysm can be obtained as follows:

[0034]

[0035]

[0036] .

[0037] Furthermore, the in vitro magnification model of intracranial aneurysm amplifies... The fluid boundary conditions for the extracorporeal circulation system are as follows: the inlet velocity of the fluid in the extracorporeal aneurysm model is set to be 1 / 3 of the inlet velocity of the actual aneurysm-bearing artery. The outlet pressure in the in vitro magnification model of an intracranial aneurysm was set to the outlet pressure of the actual aneurysm-bearing artery. The fluid flow cycle is set to a factor of the actual blood flow cycle. times.

[0038] Compared with the prior art, the present invention has the following advantages: The present invention is reasonably designed and can realize the scaled-up construction of patient-specific aneurysm models, the accurate simulation of physiological pulsatile blood flow, and the systematic monitoring of key hemodynamic parameters under the premise of meeting the flow similarity criteria. Thus, it provides a more reliable in vitro experimental platform that is closer to the physiological state for the hemodynamic study of intracranial aneurysms. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the disassembled state of the peristaltic pump in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram illustrating the relationship between angular acceleration, angular velocity, and angle in the trapezoidal algorithm of this invention.

[0042] Figure 4 This is a schematic diagram of the stepper motor speed in an embodiment of the present invention.

[0043] In the picture:

[0044] 1-Peristaltic pump head; 2-Pump tube; 3-Intracranial aneurysm external magnification model; 4-Pressure sensor; 5-Flow sensor; 6-Host computer; 7-Data cable; 8-Reservoir tank; 9-Glycerol aqueous solution; 10-Motor frame; 11-Coupling; 12-Stepper motor; 13-Bolt; 14-Driver; 15-STM32 microcontroller. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0046] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0047] like Figures 1-2 As shown, this invention discloses an extracorporeal aneurysm model blood flow circulation experimental system, aiming to overcome the problems of existing technologies, such as the inability to realistically simulate the physiological hemodynamic environment, insufficient experimental controllability, and inadequate measurement accuracy. Specifically, it includes an extracorporeal aneurysm model 3, a peristaltic pump, a reservoir 8, a flow detection device, and a pressure detection device. The reservoir 8 stores simulated blood liquid. The peristaltic pump is connected to a pump tube 2 (soft hose), one end of which is connected to the outlet of the reservoir 8, and the other end to the inlet of the extracorporeal aneurysm model 3. The peristaltic pump delivers the simulated blood liquid from the reservoir to the extracorporeal aneurysm model. The outlet of the extracorporeal aneurysm model 3 is connected to the inlet of the reservoir 8 via the soft hose, forming a complete extracorporeal circulation pathway. The flow detection device is installed at different arteries of the extracorporeal aneurysm model 3 to monitor the real-time flow of each branch of the aneurysm-bearing artery. The pressure detection device is installed at the aneurysm apex of the extracorporeal aneurysm model 3 to measure the dynamic pressure at the aneurysm apex.

[0048] In this embodiment, the blood-simulating liquid is an aqueous glycerol solution. The aqueous glycerol solution is used to simulate blood, and its density at 20°C is approximately 1150 kg / m³, and its dynamic viscosity is approximately 0.015 Pa·s, which are similar to the physical properties of blood.

[0049] In this embodiment, the peristaltic pump is driven by a stepper motor 12. The peristaltic pump head 1 periodically squeezes and releases the elastic tubing through its internal rotor to drive the fluid flow within the tubing. The rotor speed is positively correlated with the fluid flow rate. The stepper motor provides rotational power to the rotor in the peristaltic pump head. The peristaltic pump head 1 and the stepper motor 12 are fixed on a motor frame 10, and the relative positions between them are kept constant by the motor frame 10. The output shaft of the stepper motor 12 is connected to the rotor shaft of the peristaltic pump head 1 via a coupling 11.

[0050] In this embodiment, the stepper motor 12 is electrically connected to the control unit via a driver 14. The control unit generates a frequency-adjustable pulse signal corresponding to the cardiac cycle based on a trapezoidal acceleration / deceleration algorithm and drives the stepper motor to operate, thereby achieving precise control of the scaled blood flow through the peristaltic pump head. Furthermore, the control unit employs an STM32 microcontroller 15. The microcontroller controls the stepper motor to drive the peristaltic pump, reproducing the scaled physiological pulsating blood flow.

[0051] In this embodiment, the stepper motor control does not require a constant speed running phase; its acceleration and deceleration process can be referred to the appendix. Figure 3 As shown, the relevant motion curves are defined as follows:

[0052] Acceleration curve expression:

[0053]

[0054] Angular velocity curve expression:

[0055]

[0056] Angle curve expression:

[0057]

[0058] This trapezoidal acceleration / deceleration algorithm further incorporates boundary conditions calculated using the principle of flow similarity to achieve precise control of the stepper motor speed. The speed control effect can be seen in the attached diagram. Figure 4 By periodically adjusting the motor speed, the simulation of physiological blood flow pulsation waveforms can ultimately be achieved.

[0059] In this embodiment, the flow detection element is a flow sensor 5; the pressure detection element is a pressure sensor 4.

[0060] In this embodiment, a host computer 6 is also included, which is electrically connected to the flow sensor and the pressure sensor, respectively. Furthermore, the host computer uses LabVIEW software for data acquisition. Through the built-in toolkit and extension modules of the LabVIEW software, various hardware interfaces are supported. The signals output by the flow sensor and the pressure sensor are converted into standard serial communication signals via an adapter or data acquisition card and connected to the computer, realizing the synchronous acquisition, processing, and recording of the flow and pressure of the circulating system.

[0061] In this embodiment, the liquid level in the storage tank 8 is adjustable to regulate the pressure of the entire circulation system, so as to achieve the target pressure value calculated based on the similarity principle.

[0062] In this embodiment, the intracranial aneurysm external magnification model 3 is obtained by 3D printing using soft rubber material based on clinical patient CT image data. Specifically, based on the clinical patient CT image data, three-dimensional reconstruction is performed using Mimics 21.0 software, and the reconstructed model is smoothed, wall thickness is set, and scaled up proportionally using 3-matic Medical 13.0 software. Finally, the model's STL format file is imported into a 3D printer, and a solid model is obtained by printing with soft rubber material.

[0063] In this embodiment, the experimental method for blood flow circulation in an in vitro amplified model of an intracranial aneurysm includes model and boundary condition scaling, blood flow simulation, establishment of an in vitro patient-specific model and circulatory pathway, real-time monitoring and data acquisition, specifically comprising the following steps:

[0064] S1. Model and Boundary Condition Scaling: During in vitro modeling, the geometric dimensions of the actual intracranial aneurysm are enlarged by an appropriate ratio to obtain an in vitro magnified model of the intracranial aneurysm; based on the model magnification factor and the principle of flow similarity, the blood flow velocity, pressure and blood flow cycle are scaled similarly to ensure that the flow field characteristics of the in vitro magnified model of the intracranial aneurysm meet the flow similarity criteria with the actual aneurysm.

[0065] S2. Blood Flow Simulation System Construction: A peristaltic pump driven by a stepper motor controlled by a microcontroller is used to simulate scaled-down periodic blood flow changes, accurately reproducing the frequency, waveform, flow velocity, and blood pressure parameters of the cardiac cycle.

[0066] S3. Establishment of in vitro patient-specific model and circulatory pathway: The in vitro magnified model of intracranial aneurysm is connected to the reservoir using a flexible tube (the inlet of the in vitro magnified model of intracranial aneurysm is connected to the outlet of the reservoir, and the outlet of the in vitro magnified model of intracranial aneurysm is connected to the inlet of the reservoir), thus forming a closed blood circulation pathway.

[0067] S4. Real-time monitoring and data acquisition: Install flow sensors and pressure sensors in the circulation path to collect and record flow rate and pressure data in real time during the experiment.

[0068] In this embodiment, model and boundary condition scaling is used to overcome the difficulties in in vitro modeling and observation caused by the small size of actual aneurysms, thereby appropriately enlarging the model aneurysm. The scaling process must strictly follow the flow similarity criteria to ensure that the flow field of the model is consistent with the dynamic characteristics of the actual aneurysm, thus achieving effective experimental observation and measurement. The specific similarity criteria are as follows.

[0069] S11, Geometric Similarity

[0070] Geometric similarity requires that the one-dimensional parameters of the magnified in vitro model of the intracranial aneurysm be proportional to those of the prototype aneurysm, such as the diameter and length of the parent artery, and the height and width of the aneurysm; its expression is:

[0071]

[0072] in, For one-dimensional parameters, The scale factor is m, and the subscripts m and p are the external magnification model and the prototype aneurysm of the intracranial aneurysm, respectively (the same applies below).

[0073] S12, Reynolds number similarity

[0074] Reynolds number similarity requires that the ratio of inertial force to viscous force in the external magnification model and the prototype flow field of an intracranial aneurysm be equal, and its expression is:

[0075]

[0076] in, For fluid density, For fluid velocity, This refers to dynamic viscosity.

[0077] S13, Euler number similarity

[0078] Euler number similarity requires that the ratio of inertial force to pressure in the external magnification model of an intracranial aneurysm be equal to that in the prototype flow field. The expression for this is:

[0079]

[0080] in, For pressure.

[0081] S14, similar to Wormersley number

[0082] The Wormsley number similarity requirement dictates that the ratio of unsteady inertial forces and pressures in the external magnification model of an intracranial aneurysm must be equal to the ratio in the prototype flow field. Its expression is:

[0083]

[0084] in, ω is the angular frequency of the pulsation.

[0085] In this embodiment, the density and dynamic viscosity of the fluid in the external magnification model of intracranial aneurysm are set to be the same as those in the actual flow field, i.e. , Based on the above similarity criteria, the proportional relationship between the external magnification model and the prototype of an intracranial aneurysm can be obtained as follows:

[0086]

[0087]

[0088] .

[0089] In this embodiment, based on the above proportional relationship, it can be determined that the intracranial aneurysm external magnification model is magnified. The fluid boundary conditions for the extracorporeal circulation system are as follows: the inlet velocity of the fluid in the extracorporeal aneurysm model is set to be 1 / 3 of the inlet velocity of the actual aneurysm-bearing artery. The outlet pressure in the in vitro magnification model of an intracranial aneurysm was set to the outlet pressure of the actual aneurysm-bearing artery. The fluid flow cycle is set to a factor of the actual blood flow cycle. times.

[0090] By applying the principle of flow similarity to model construction, boundary condition setting, and experimental system integration, a high degree of reproduction from geometric structure to flow dynamics is achieved. This overcomes the problems of small size, difficult observation, and flow distortion in traditional in vitro models, and realizes controllable and repeatable in vitro hemodynamic experiments, providing an important method for the study of the mechanism of intracranial aneurysms and the verification of numerical simulation results.

[0091] In summary, this invention systematically applies the principle of flow similarity to the construction and blood flow simulation of an in vitro experimental model of intracranial aneurysms, achieving a complete reproduction from patient-specific geometry to physiological pulsating flow fields. In practice, the above steps are followed sequentially to complete model scaling, system construction, loop connection, and data acquisition, thus forming a highly integrated, parameter-controllable, and precisely measured in vitro hemodynamic experimental platform. This invention not only solves the observation difficulties and flow distortion problems caused by the small scale in traditional in vitro models, but also achieves high-fidelity simulation and real-time monitoring of key dynamic parameters such as blood flow velocity and pressure through precise microcontroller control and synchronous acquisition by multiple sensors. The system's construction method is clear and feasible, with good repeatability and scalability. It can provide near-physiological experimental evidence for the study of the formation, development, and rupture mechanisms of intracranial aneurysms, and also provides an important method for verifying numerical simulation results.

[0092] The advantages of this invention are:

[0093] (1) It realizes the proportional scaling from real micro aneurysms to observable models. By using the flow similarity criteria of physical quantities such as geometry, Reynolds number, Euler number and Wormsley number, it not only realizes the proportional scaling of the model, but also ensures that the flow field dynamics characteristics of the scaled-up model are strictly similar to those of real aneurysms. This solves the key problem that traditional in vitro models are difficult to observe due to their small size and that the flow state is distorted.

[0094] (2) Provides highly realistic physiological pulsating blood flow simulation: The control strategy based on the trapezoidal acceleration and deceleration algorithm of the microcontroller is adopted to drive the peristaltic pump to push the fluid flow at different speeds, thereby reproducing the blood flow waveform, frequency and pressure changes in the human cardiac cycle. This overcomes the simulation distortion caused by the use of constant flow or simple periodic flow in the existing technology, and significantly improves the physiological authenticity and reliability of hemodynamic experiments.

[0095] (3) An integrated and controllable personalized experimental platform was constructed: the patient-specific 3D printed model, the pressure control system based on the adjustable liquid level, the closed-loop circulation loop and the multi-sensor real-time monitoring system were organically integrated to form an integrated experimental scheme from model construction, boundary condition setting to data acquisition, which supports systematic and controllable hemodynamic studies on specific cases.

[0096] If this invention discloses or relates to components or structural parts that are fixedly connected to each other, then, unless otherwise stated, a fixed connection can be understood as: a fixed connection that can be detached (e.g., using bolts or screws), or a fixed connection that cannot be detached (e.g., riveting, welding). Of course, a fixed connection can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0097] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0098] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An experimental system for an in vitro amplification model of intracranial aneurysm blood flow circulation, characterized in that: The device includes an extracorporeal magnification model of an intracranial aneurysm, a peristaltic pump, a reservoir, a flow detection device, and a pressure detection device. The reservoir stores blood-like simulated liquid. The peristaltic pump is connected to a pump tube, one end of which is connected to the outlet of the reservoir and the other end to the inlet of the extracorporeal magnification model of the intracranial aneurysm. The outlet of the extracorporeal magnification model of the intracranial aneurysm is connected to the inlet of the reservoir, forming an extracorporeal circulation pathway. The flow detection device is located at different arteries of the extracorporeal magnification model of the intracranial aneurysm. The pressure detection device is located at the top of the aneurysm of the extracorporeal magnification model of the intracranial aneurysm.

2. The intracranial aneurysm extracorporeal amplification model blood flow circulation experimental system according to claim 1, characterized in that: The blood-simulating fluid is an aqueous solution of glycerol.

3. The intracranial aneurysm extracorporeal amplification model blood flow circulation experimental system according to claim 1, characterized in that: The peristaltic pump is driven by a stepper motor, which is electrically connected to the control unit via a driver. The control unit generates a frequency-adjustable pulse signal corresponding to the cardiac cycle based on a trapezoidal acceleration / deceleration algorithm and drives the stepper motor to operate.

4. The intracranial aneurysm extracorporeal amplification model blood flow circulation experimental system according to claim 1, characterized in that: It also includes a host computer, which is electrically connected to the flow detection device and the pressure detection device respectively.

5. The intracranial aneurysm extracorporeal amplification model blood flow circulation experimental system according to claim 1, characterized in that: The liquid level in the storage tank is adjustable.

6. The intracranial aneurysm extracorporeal amplification model blood flow circulation experimental system according to claim 1, characterized in that: The in vitro magnified model of the intracranial aneurysm was obtained by 3D printing using soft rubber material based on CT image data of clinical patients.

7. A method for experimental blood flow circulation in an in vitro magnified model of an intracranial aneurysm, characterized in that: The system includes an in vitro amplification model of intracranial aneurysm blood flow circulation experimental system as described in claim 3, comprising the following steps: S1. Model and Boundary Condition Scaling: During in vitro modeling, the geometric dimensions of the actual intracranial aneurysm are scaled up proportionally to obtain an in vitro magnified model of the intracranial aneurysm. Based on the model magnification factor and the principle of flow similarity, the blood flow velocity, pressure and blood flow cycle are scaled up to ensure that the flow field characteristics of the in vitro magnified model of the intracranial aneurysm meet the flow similarity criteria with the actual aneurysm. S2. Blood flow simulation system construction: The peristaltic pump driven by the stepper motor is controlled by the control unit to simulate the scaled periodic blood flow changes and reproduce the frequency, waveform, flow rate and blood pressure parameters of the cardiac cycle. S3. Establishment of in vitro patient-specific models and circulatory pathways: Connect the in vitro magnified model of intracranial aneurysm to the reservoir to form a closed blood circulation pathway; S4. Real-time monitoring and data acquisition: Install flow and pressure sensors in the circulation path to collect and record flow rate and pressure data in real time during the experiment.

8. The method for experimental blood flow circulation in an in vitro magnified model of an intracranial aneurysm according to claim 7, characterized in that: The specific similarity criteria in step S1 are as follows: S11, Geometric Similarity Geometric similarity requires that the one-dimensional parameters of the in vitro magnified model of the intracranial aneurysm be proportional to those of the aneurysm prototype, expressed as: in, For one-dimensional parameters, The scale factor is m, and the subscripts m and p are the external magnification model and the prototype aneurysm of the intracranial aneurysm, respectively. S12, Reynolds number similarity Reynolds number similarity requires that the ratio of inertial force to viscous force in the external magnification model and the prototype flow field of an intracranial aneurysm be equal, and its expression is: in, For fluid density, For fluid velocity, Dynamic viscosity; S13, Euler number similarity Euler number similarity requires that the ratio of inertial force to pressure in the external magnification model of an intracranial aneurysm be equal to that in the prototype flow field. The expression for this is: in, For pressure; S14, similar to Wormersley number The Wormsley number similarity requirement dictates that the ratio of unsteady inertial forces and pressures in the external magnification model of an intracranial aneurysm must be equal to the ratio in the prototype flow field. Its expression is: in, ω is the angular frequency of the pulsation.

9. The experimental method for blood flow circulation in an in vitro magnified model of an intracranial aneurysm according to claim 8, characterized in that: The density and dynamic viscosity of the fluid in the in vitro magnification model of an intracranial aneurysm are set to be the same as those in the actual flow field, i.e. , Based on the above similarity criteria, the proportional relationship between the external magnification model and the prototype of an intracranial aneurysm can be obtained as follows: 。 10. The method for experimental blood flow circulation in an in vitro magnified model of an intracranial aneurysm according to claim 9, characterized in that: The intracranial aneurysm external magnification model was enlarged. The fluid boundary conditions for the extracorporeal circulation system are as follows: the inlet velocity of the fluid in the extracorporeal aneurysm model is set to be 1 / 3 of the inlet velocity of the actual aneurysm-bearing artery. The outlet pressure in the in vitro magnification model of an intracranial aneurysm was set to the outlet pressure of the actual aneurysm-bearing artery. The fluid flow cycle is set to a factor of the actual blood flow cycle. times.

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