In-vitro left heart near physiological environment simulation system and method based on isolated heart

Abstract

The invention relates to an in-vitro left heart near physiological environment simulation system and method based on an isolated heart, and relates to the technical field of medical instruments. The system comprises a simulation assembly and an external circulation unit. A shell of the simulation assembly is transparent and used for containing the isolated heart, a top cover is provided with an inflow channel, an outflow channel and an observation window, and a reciprocating pump changes a containing cavity through an isolating membrane to hydraulically drive the heart. The external circulation unit is provided with a resistance valve, a compliance assembly and the like. The method comprises the steps of treating the isolated heart, connecting pipelines, assembling parts, adjusting liquid flow and pressure and the like. The left heart dynamic near-physiological simulation of the isolated heart can be realized, the valve movement can be conveniently observed, and the heart movement can be observed from different angles. More importantly, a near-physiological in-vitro testing environment can be provided for cardiovascular implantation and intervention medical instruments (such as an intervention type mitral valve, a mitral valve forming ring and a ventricular septum plugging device), and a way is provided for researching the influence of the near-physiological in-vitro testing environment on valve movement and left heart movement.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an extracorporeal left heart near-physiological environment simulation system and method based on an isolated heart. Background Art

[0002] In vitro evaluation plays a vital role in the design and verification of implantable medical devices. Especially for cardiac implants such as interventional artificial valves, mitral valve shaping rings, ventricular septal occluders, blood pumps, etc., when evaluating their functions, biomechanical properties, damage mechanisms and other parameters, an in vitro near-physiological simulation device that can simulate the complex biomechanical environment of the heart is needed.

[0003] In order to accurately simulate the complex movement of the heart's myocardium and its subvalvular structures as well as the flow field in the ventricle, existing simulation methods usually adopt the following methods:

[0004] (1) Driving an isolated animal heart: Using an isolated heart for simulation, especially the pig heart, which is the first choice because its anatomical structure is closest to the human heart.

[0005] (2) 3D printed heart model: The heart model is manufactured by 3D printing technology, which is easy to integrate with the pulsatile flow platform, but it is difficult to fully replicate the biomechanical properties of the heart.

[0006] (3) Heart model cast with polyvinyl alcohol: The heart model cast with polyvinyl alcohol material is also convenient for integration with the pulsatile flow platform, but it has limitations in simulating the biomechanical properties of the heart.

[0007] In order to drive the dynamic motion of the heart model, two different pressurization methods are usually used:

[0008] ① Internal pressurization method: The reciprocating pump is connected to the ventricle through a hollow connector at the apex of the heart, and the liquid is periodically injected / extracted from the left ventricle to simulate cardiac movement. The characteristic of this pressurization method is that the liquid in the reciprocating pump participates in the systemic circulation, but the change in ventricular volume is opposite to the physiological state.

[0009] ② External pressurization method: Place the heart model in a container filled with liquid, and use vacuum technology to form a closed space. Use a reciprocating pump to periodically inject / extract liquid into the container to drive the movement of the ventricular wall. In this method, the liquid in the reciprocating pump does not participate in the systemic circulation, and the change in ventricular volume is consistent with the physiological state.

[0010] Although the above methods can simulate the dynamic process of the heart to a certain extent, there are still some key problems:

[0011] 1) Ex vivo animal heart model: Although it can simulate the biomechanical properties of the heart well, there is currently a lack of a device that can maintain the structure and function of the aortic valve and mitral valve of the heart and is convenient for access to the pulsatile flow platform;

[0012] 2) Although the external pressurization method can simulate physiological ventricular volume changes, fixing the apex and base of the heart leads to the fixation of the mitral valve ring and the aortic valve ring, which is inconsistent with the physiological situation;

[0013] 3) Observation of valve movement: In the prior art, observation of valve movement mainly relies on endoscopes, which require additional branch circuits and complicated installation processes.

[0014] The technical problems mentioned above indicate that there is an urgent need in the market for an improved in vitro near-physiological cardiac simulation device that can more accurately simulate the physiological movement of the heart while simplifying the observation process of valve movement. Summary of the invention

[0015] The purpose of the present invention is to provide an in vitro left heart quasi-physiological environment simulation system and method based on an isolated heart, so as to solve the problems existing in the above-mentioned prior art, realize in vitro left heart quasi-physiological environment simulation, and facilitate the observation of valve movement.

[0016] To achieve the above object, the present invention provides the following solutions:

[0017] The present invention provides an extracorporeal left heart near-physiological environment simulation system based on an isolated heart, comprising:

[0018] A simulation component, which includes a shell, a top cover and a reciprocating pump. The shell is transparent, and a accommodating chamber is arranged in the shell, and the accommodating chamber is used to place an isolated heart. The top surface of the shell is provided with a first opening, and one side of the shell is provided with a second opening. The bottom of the shell is provided with a liquid passage, and a first plug is detachably installed at the liquid passage; the top cover is sealed with the top surface of the shell, and the first opening is located directly below the top cover, and the top cover includes a top plate and an inclined plate; an inflow channel and a first joint connected to the inflow channel are fixedly provided on the top plate, and an outflow channel and a second joint connected to the outflow channel are fixedly provided on the inclined plate; an end of the inflow channel close to the accommodating chamber is used to connect to the isolated heart through a first connecting pipe. The left atrium and ventricle of the isolated heart are connected, one end of the outflow channel close to the accommodating chamber is used to communicate with the aorta on the isolated heart through the second connecting tube, and the top cover is also detachably mounted with a first observation window and a second observation window, the first observation window is opposite to the end of the inflow channel away from the accommodating chamber, and the second observation window is opposite to the end of the outflow channel away from the accommodating chamber; the liquid inlet and the liquid outlet of the reciprocating pump are respectively sealedly connected to the first end of the third connecting tube, the second end of the third connecting tube is sealedly connected to the side wall of the shell, and the third connecting tube is opposite to the second opening, and an isolation membrane is provided at the second opening, the isolation membrane isolates the third connecting tube from the accommodating chamber, and the area of ​​the isolation membrane is larger than the area of ​​the second opening;

[0019] An external circulation unit, the external circulation unit includes a first flow meter, a first resistance valve, a compliance component, a second resistance valve, a liquid storage container and a second flow meter, the compliance component includes an injection and exhaust device, a three-way valve, a first container and a second container distributed from top to bottom, the bottom end of the first container is connected to the second container, the first container is sealed, one end of the second container is connected to the second joint through a first pipeline, and the other end is connected to the liquid storage container through a second pipeline, the top of the first container is connected to the first interface of the three-way valve, the vent of the injection and exhaust device is connected to the second interface of the three-way valve, the third interface of the three-way valve is connected to the atmosphere, the injection and exhaust device is used to evacuate or inject air into the first container; the top of the liquid storage container is open, and the liquid storage container is also connected to the first joint through a third pipeline, the first flow meter and the first resistance valve are respectively arranged on the first pipeline, the second resistance valve is arranged on the second pipeline, and the second flow meter is arranged on the third pipeline.

[0020] Preferably, the angle between the top plate and the inclined plate is a first angle, the angle between the annular plane of the aortic valve and the annular plane of the mitral valve in the isolated heart is a second angle, and the first angle is equal to the second angle.

[0021] Preferably, the shell is in a polyhedral shape; the isolation membrane is sealed and connected to the shell; and the first joint and the second joint both adopt pagoda joints.

[0022] Preferably, a cavity pressure measuring interface is also provided on the top cover, and the cavity pressure measuring interface is used to install a pressure sensor; the cavity pressure measuring interface is communicated with the accommodating cavity.

[0023] Preferably, the top cover is also provided with a left atrial pressure measuring interface, and the left atrial pressure measuring interface is used to install a pressure sensor; the left atrial pressure measuring interface is communicated with the inflow channel;

[0024] The inclined plate is provided with an aortic pressure measuring interface which is in communication with the outflow channel, and the aortic pressure measuring interface is used for installing a pressure sensor.

[0025] Preferably, the top cover is also provided with a left ventricular pressure measuring interface, and the left ventricular pressure measuring interface is used to install a pressure sensor; it also includes a left ventricular pressure measuring assembly, and the left ventricular pressure measuring assembly includes a connecting hose and a pressure measuring head, and the pressure measuring head is in the shape of a hollow cylinder, one end of the connecting hose is sealedly connected to the left ventricular pressure measuring interface, and the other end is sealedly connected to one end of the pressure measuring head, the other end of the pressure measuring head is pointed and provided with a plurality of openings, and the end of the pressure measuring head away from the connecting hose is used for insertion into the left ventricle of the isolated heart.

[0026] Preferably, an exhaust interface is provided at the top end of the third connecting pipe, and a second plug is detachably installed at the exhaust interface.

[0027] Preferably, a first sealing ring is sandwiched between the top cover and the shell, a second sealing ring and a third sealing ring are sandwiched between the third connecting pipe and the shell, and the outer diameter of the second sealing ring is smaller than the inner diameter of the third sealing ring.

[0028] The present invention also provides an in vitro left heart quasi-physiological environment simulation method based on an isolated heart, based on the above-mentioned in vitro left heart quasi-physiological environment simulation system based on an isolated heart, comprising the following steps:

[0029] (1) Processing the isolated heart, trimming unnecessary blood vessels, retaining the aortic root, and clamping the left and right coronary arteries from the coronary artery root, so that the left heart of the isolated heart forms a left atrium-left ventricle-aorta circuit without other side branches;

[0030] (2) Fixing the first connecting tube with a cable tie so that the first connecting tube is connected to the left atrioventricular orifice of the isolated heart; fixing the second connecting tube with a cable tie so that the second connecting tube is connected to the aortic orifice of the isolated heart; connecting the first connecting tube with the inflow channel through a hose, connecting the second connecting tube with the outflow channel through a hose, and installing the first observation window and the second observation window on the top cover so that a passage of inflow channel-isolated heart-outflow channel is formed between the isolated heart and the top cover, and checking the sealing of the isolated heart and the top cover;

[0031] (3) Assembling the top cover and the housing by screws, and assembling the housing, the third connecting pipe and the reciprocating pump by screws, and pre-filling the third connecting pipe with the first liquid;

[0032] (4) Assemble the external circulation unit and ensure that the first pipeline is connected to the second joint and the third pipeline is connected to the first joint;

[0033] (5) removing the first plug and filling the accommodating cavity with the second liquid through the liquid passage;

[0034] (6) installing a first plug and injecting a third liquid into the passage of the external circulation unit;

[0035] (7) starting the reciprocating pump;

[0036] (8) Perform simulation.

[0037] Preferably, after performing step (7) and before performing step (8), the following steps need to be performed:

[0038] S1. Determine the standard flow value of the system during operation according to the type of simulation experiment to be performed and the guidelines for fluid mechanics performance verification in the international standard ISO 5840;

[0039] Observe the first flow meter to obtain the actual flow value of the isolated heart-based extracorporeal left heart near-physiological environment simulation system, and adjust the output amplitude of the reciprocating pump so that the actual flow value is equal to the standard flow value;

[0040] S2, monitoring the pressure value of the aorta, the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart;

[0041] When the mean aortic pressure and the mean left ventricular pressure of the isolated heart are greater than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the resistance value of the second resistance valve is reduced until the mean aortic pressure and the mean left ventricular pressure of the isolated heart meet the fluid mechanics performance verification guidelines in the international standard ISO 5840; when the mean aortic pressure and the mean left ventricular pressure of the isolated heart are less than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the resistance value of the second resistance valve is increased until the mean aortic pressure and the mean left ventricular pressure of the isolated heart meet the fluid mechanics performance verification guidelines in the international standard ISO 5840;

[0042] When the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, but the floating range of the mean pressure of the aorta of the isolated heart is greater than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, part of the air in the first container is extracted by means of an air extraction and injection device until the floating range of the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840; When the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, but the floating range of the mean pressure of the aorta of the isolated heart is less than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, air is injected into the first container by means of an air extraction and injection device until the floating range of the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840;

[0043] If the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart are all higher than the fluid mechanics performance verification guidelines in the international standard ISO 5840, a portion of the third liquid is extracted from the liquid storage container to lower the liquid level in the liquid storage container until the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart meet the fluid mechanics performance verification guidelines in the international standard ISO 5840; if the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart are all lower than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the third liquid is continuously injected into the liquid storage container to raise the liquid level in the liquid storage container until the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart meet the fluid mechanics performance verification guidelines in the international standard ISO 5840;

[0044] If the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart both comply with the guidelines for fluid mechanics performance verification in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart is lower than the guidelines for fluid mechanics performance verification in the international standard ISO 5840, then the resistance value of the first resistance valve is increased until the pressure value of the aorta of the isolated heart complies with the guidelines for fluid mechanics performance verification in the international standard ISO 5840; If the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart both comply with the guidelines for fluid mechanics performance verification in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart is higher than the guidelines for fluid mechanics performance verification in the international standard ISO 5840, then the resistance value of the first resistance valve is reduced until the pressure value of the aorta of the isolated heart complies with the guidelines for fluid mechanics performance verification in the international standard ISO 5840;

[0045] S3. Adjust the driving curve of the reciprocating pump so that the isolated heart is driven in a manner consistent with the law of ventricular volume change during the heartbeat cycle of a healthy person.

[0046] Compared with the prior art, the present invention has achieved the following technical effects:

[0047] The in vitro left heart quasi-physiological environment simulation system and method based on an isolated heart provided by the present invention can realize the dynamic simulation of the in vitro left heart quasi-physiological environment, and facilitate the observation of valve movement. It also provides a quasi-physiological in vitro testing environment for cardiovascular implantable medical devices, and provides a way to study the influence of cardiovascular implantable medical devices on valve movement and left heart movement.

[0048] Furthermore, during the simulation process, the present invention places the isolated heart in a containing chamber filled with liquid, and the isolated heart is not fixed, thereby being able to more accurately simulate the physiological movement of the isolated heart; the movement of the mitral valve can be conveniently observed through the first observation window, and the movement of the aortic valve can be conveniently observed through the second observation window.

[0049] Furthermore, the shell of the present invention is transparent and polyhedral, which is convenient for observing the movement of the isolated heart from different angles and can facilitate real-time three-dimensional movement measurement of the ventricular wall.

[0050] Furthermore, both the inflow channel and the outflow channel are transparent, so the flow of the circulating liquid can be easily observed.

[0051] Furthermore, the present invention can achieve the technical effect of in vitro left heart pathological simulation (hypertension, hypotension, heart failure, etc.) under various conditions (such as hypertension, hypotension, heart failure, etc.) by adjusting the compliance chamber, the resistance of the first resistance valve, the resistance of the second resistance valve, the liquid level of the liquid storage chamber and the displacement curve of the piston.

[0052] Furthermore, the second flow meter can measure the flow rate of the liquid flowing back from the mitral valve position of the isolated heart to the liquid storage container when the mitral valve is closed during the normal circulation process of the circulation loop formed by the left heart of the isolated heart and the external circulation unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 It is a structural schematic diagram of an in vitro left heart near-physiological environment simulation system based on an isolated heart of the present invention;

[0055] Figure 2 The schematic diagram of the partial structure of the simulation components in the extracorporeal left heart near physiological environment simulation system based on the isolated heart of the present invention is as follows Figure 1 ;

[0056] Figure 3 The schematic diagram of the partial structure of the simulation components in the extracorporeal left heart near physiological environment simulation system based on the isolated heart of the present invention is as follows Figure 2 ;

[0057] Figure 4 It is a structural schematic diagram of the first connecting tube in the extracorporeal left heart near-physiological environment simulation system based on an isolated heart of the present invention;

[0058] Figure 5 It is a structural schematic diagram of the second connecting tube in the extracorporeal left heart near-physiological environment simulation system based on an isolated heart of the present invention;

[0059] Figure 6 It is a schematic structural diagram of the third connecting tube in the in vitro left heart near-physiological environment simulation system based on an isolated heart of the present invention;

[0060] Figure 7 It is a schematic structural diagram of a shell in the in vitro left heart near-physiological environment simulation system based on an isolated heart of the present invention;

[0061] Figure 8 The schematic diagram of the partial structure of the simulation components in the extracorporeal left heart near physiological environment simulation system based on the isolated heart of the present invention is as follows Figure 3 ;

[0062] Fig. 9 The schematic diagram of the partial structure of the simulation components in the extracorporeal left heart near physiological environment simulation system based on the isolated heart of the present invention is as follows Figure 4 ;

[0063] Fig.10 The schematic diagram of the partial structure of the simulation components in the extracorporeal left heart near physiological environment simulation system based on the isolated heart of the present invention is as follows Figure 5 ;

[0064] Fig.11 The schematic diagram of the partial structure of the simulation components in the extracorporeal left heart near physiological environment simulation system based on the isolated heart of the present invention is as follows Figure 6 ;

[0065] In the figure: 1, shell; 2, top cover; 3, first observation window; 4, second observation window; 5, second joint; 6, first joint; 7, third connecting pipe; 8, exhaust interface; 9, connecting hose; 10, pressure measuring head; 11, left atrial pressure measuring interface; 12, left ventricular pressure measuring interface; 13, inflow channel; 14, outflow channel; 15, first connecting pipe; 16, second connecting pipe; 17, first opening; 18, second opening; 19, first plug; 20, cavity pressure measuring interface; 21, reciprocating pump; 22, isolated heart; 23, first flowmeter; 24, first resistance valve; 25, second container; 26, first container; 27, second resistance valve; 28, liquid storage container; 29, first pipeline; 30, second pipeline; 31, third pipeline; 32, aortic pressure measuring interface; 33, three-way valve; 34, injection and exhaust device; 35, second flowmeter. DETAILED DESCRIPTION

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] The purpose of the present invention is to provide an in vitro left heart quasi-physiological environment simulation system and method based on an isolated heart, so as to solve the problems existing in the above-mentioned prior art, realize in vitro left heart quasi-physiological environment simulation and facilitate observation of valve movement.

[0068] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0069] Embodiment 1

[0070] like Figures 1 to 11 As shown, this embodiment provides an in vitro left heart near-physiological environment simulation system based on an isolated heart, comprising:

[0071] A simulation component, the simulation component includes a shell 1, a top cover 2 and a reciprocating pump 21, the shell 1 is transparent, a containing cavity is arranged in the shell 1, the containing cavity is used to place an isolated heart 22, a first opening 17 is arranged on the top surface of the shell 1, a second opening 18 is arranged on one side of the shell 1, a liquid passage is arranged at the bottom of the shell 1, and a first plug 19 is detachably installed at the liquid passage; the top cover 2 is sealedly connected to the top surface of the shell 1, the first opening 17 is located directly below the top cover 2, and the top cover 2 includes a top plate and an inclined plate; an inflow channel 13 and a first connector 6 connected to the inflow channel 13 are fixedly arranged on the top plate, and an outflow channel 14 and a second connector 5 connected to the outflow channel 14 are fixedly arranged on the inclined plate; one end of the inflow channel 13 close to the containing cavity is used to be connected to the left atrioventricular orifice of the isolated heart 22 through a first connecting tube 15 The outflow channel 14 is connected to the aorta on the isolated heart 22 through the second connecting tube 16. The top cover 2 is also detachably provided with a first observation window 3 and a second observation window 4. The first observation window 3 is opposite to the end of the inflow channel 13 away from the accommodating chamber, and the second observation window 4 is opposite to the end of the outflow channel 14 away from the accommodating chamber. The reciprocating pump 21 has a liquid inlet and a liquid outlet sealedly connected to the first end of the third connecting tube 7, respectively. The second end of the third connecting tube 7 is sealedly connected to the side wall of the housing 1, and the third connecting tube 7 is opposite to the second opening 18. An isolation membrane (not shown in the figure) is provided at the second opening 18. The isolation membrane isolates the third connecting tube 7 from the accommodating chamber, and the area of ​​the isolation membrane is larger than the area of ​​the second opening 18. The liquid inlet of the reciprocating pump 21 is connected to the liquid source.

[0072] The external circulation unit includes a first flow meter 23, a first resistance valve 24, a compliance component, a second resistance valve 27, a liquid storage container 28 and a second flow meter 35. The compliance component includes an injection and exhaust device 34, a three-way valve 33, a first container 26 and a second container 25 distributed from top to bottom. The bottom end of the first container 26 is connected to the second container 25, and the first container 26 is sealed. One end of the second container 25 is connected to the second joint 5 through a first pipeline 29, and the other end is connected to the liquid storage container 28 through a second pipeline 30. The top end of the first container 26 is connected to the first interface of the three-way valve 33, the vent of the injection and exhaust device 34 is connected to the second interface of the three-way valve 33, and the third interface of the three-way valve 33 is connected to the atmosphere. The injection and exhaust device 34 is used to evacuate or inject gas into the first container 26; in this embodiment, the injection and exhaust The device 34 adopts a syringe. In practical applications, the injection and exhaust device 34 can also adopt other types of injection and exhaust devices 34 such as air bags; when it is necessary to evacuate the first container 26, the three-way valve 33 is switched so that the second interface of the three-way valve 33 is connected to the third interface, and then the handle of the syringe is pressed (i.e., the injection and exhaust device 34), and then the three-way valve 33 is switched so that the first interface of the three-way valve 33 is connected to the second interface, that is, the injection and exhaust device 34 is connected to the first container, and then the handle of the syringe is pulled to evacuate the first container 26 through the syringe; when it is necessary to inject gas into the first container 26, the three-way valve 33 is switched so that the first interface of the three-way valve 33 is connected to the second interface, that is, the injection and exhaust device 34 is connected to the first container, and then the handle of the syringe is pressed to inject gas into the first container 26 through the syringe;

[0073] The top of the liquid storage container 28 is open, and the liquid storage container 28 is also connected to the first connector 6 through the third pipeline 31. The first flowmeter 23 and the first resistance valve 24 are respectively arranged on the first pipeline 29, the second resistance valve 27 is arranged on the second pipeline 30, and the second flowmeter 35 is arranged on the third pipeline; when the circulation loop formed by the left heart of the isolated heart 22 and the external circulation unit circulates normally, the first flowmeter 23 and the second flowmeter 35 can be used to measure the flow rate of the circulation loop; and during the normal circulation process of the circulation loop formed by the left heart of the isolated heart and the external circulation unit, when the mitral valve is closed, part of the liquid will flow back from the mitral valve position of the isolated heart to the liquid storage container, and the second flowmeter 35 can be used to measure the flow rate of the liquid flowing back from the pre-valve position of the mitral valve of the isolated heart to the liquid storage container.

[0074] When the reciprocating pump 21 is working, it periodically sucks the liquid in the third connecting tube 7 or discharges the liquid into the third connecting tube 7, so that the volume of the liquid in the third connecting tube 7 changes. When the volume of the liquid in the third connecting tube 7 changes, the isolation membrane will be driven to move. The movement of the isolation membrane will cause the hydraulic pressure in the accommodating chamber to change. The change in the hydraulic pressure in the accommodating chamber causes the isolated heart 22 to contract and relax, thereby performing a near-physiological simulation of the isolated heart 22.

[0075] In this embodiment, it is more preferred that the angle between the top plate and the inclined plate is the first angle, the angle between the annular plane of the aortic valve and the annular plane of the mitral valve in the isolated heart 22 is the second angle, and the first angle is equal to the second angle; through the design of the top plate and the inclined plate, it is convenient to complete the in vitro near-physiological simulation of the isolated heart 22 without changing the physiological angle between the mitral valve and the aortic valve, so that the simulation process is more accurate.

[0076] In this embodiment, it is more preferred that the shell 1 is in a polyhedron shape. The polyhedron design is convenient for setting up multiple cameras from different angles to capture the heart movement in real time, which is convenient for in vitro evaluation.

[0077] In this embodiment, it is more preferred that the isolation membrane is sealed and connected to the shell 1. The isolation membrane isolates the liquid in the accommodating cavity in the shell 1 from the liquid in the third connecting pipe 7, which can prevent the liquid in the accommodating wall from contaminating the liquid pumped by the reciprocating pump 21, thereby ensuring the working stability of the reciprocating pump 21 and improving the service life of the reciprocating pump 21.

[0078] In this embodiment, it is more preferred that a cavity pressure measuring interface 20, a left atrial pressure measuring interface 11 and a left ventricular pressure measuring interface 12 are also provided on the top cover 2, and this embodiment also includes a left ventricular pressure measuring assembly; the cavity pressure measuring interface 20, the left atrial pressure measuring interface 11 and the left ventricular pressure measuring interface 12 are used to install a pressure sensor. Specifically, an interface matching the cavity pressure measuring interface 20, the left atrial pressure measuring interface 11 and the left ventricular pressure measuring interface 12 is provided on the pressure sensor, so as to facilitate the installation of the pressure sensor on the cavity pressure measuring interface 20, the left atrial pressure measuring interface 11 or the left ventricular pressure measuring interface 12.

[0079] The cavity pressure measuring interface 20 is communicated with the accommodating cavity. When a pressure sensor is installed on the cavity pressure measuring interface 20, the pressure value in the accommodating cavity can be directly measured; an aortic pressure measuring interface 32 connected to the outflow channel 14 is provided on the inclined plate, and the aortic pressure measuring interface 32 is used to install a pressure sensor; when in use, a pressure sensor is usually required to be installed on the cavity pressure measuring interface 20, the left atrial pressure measuring interface 11, the aortic pressure measuring interface 32 and the left ventricular pressure measuring interface 12 respectively, to facilitate pressure monitoring.

[0080] Since the aortic pressure measuring interface 32 is connected to the outflow channel 14, and the outflow channel 14 is connected to the aortic opening on the isolated heart 22 through the second connecting tube 16, a pressure sensor is installed on the aortic pressure measuring interface 32 to directly measure the pressure value of the aortic pressure.

[0081] The left atrial pressure measuring interface 11 is in communication with the inflow channel 13. Since the inflow channel 13 is in communication with the left atrium of the isolated heart 22 through the first connecting tube 15, when a pressure sensor is installed on the left atrial pressure measuring interface 11, the pressure value in the left atrium of the isolated heart 22 can be directly measured.

[0082] The left ventricular pressure measuring assembly includes a connecting hose 9 and a pressure measuring head 10. The pressure measuring head 10 is in the shape of a hollow cylinder. One end of the connecting hose 9 is sealedly connected to the left ventricular pressure measuring interface 12, and the other end is sealedly connected to one end of the pressure measuring head 10. The other end of the pressure measuring head 10 is pointed and provided with a plurality of openings. The end of the pressure measuring head 10 away from the connecting hose 9 is used to insert into the left ventricle of the isolated heart 22. Since the tip of the pressure measuring head 10 is inserted into the left ventricle, the liquid in the left ventricle can communicate with the left ventricular pressure measuring interface 12 through the pressure measuring head 10, the connecting hose 9, and the left ventricular pressure measuring interface 12. Therefore, when a pressure sensor is installed on the left ventricular pressure measuring interface 12, the pressure value in the left ventricle of the isolated heart 22 can be directly measured. It should be noted that during use, it is necessary to ensure the sealed connection between the pressure measuring head 10 and the isolated heart 22 to avoid leakage of the liquid in the left ventricle of the isolated heart 22 from between the isolated heart 22 and the pressure measuring head 10.

[0083] In this embodiment, it is more preferred that an exhaust interface 8 is provided at the top end of the third connecting tube 7, and a second plug is detachably installed at the exhaust interface 8; the function of the exhaust interface 8 is to facilitate the discharge of gas in the third connecting tube 7 when liquid is filled into the third connecting tube 7. After the third connecting tube 7 is filled with liquid, the exhaust interface 8 is sealed with the second plug to prevent the liquid in the third connecting tube 7 from leaking from the exhaust interface 8.

[0084] A first sealing ring is sandwiched between the top cover 2 and the shell 1, and the sealing of the connection between the top cover 2 and the shell 1 is enhanced by the first sealing ring; the third connecting pipe 7 in this embodiment is conical, and a second sealing ring and a third sealing ring are sandwiched between the third connecting pipe 7 and the shell 1, and the outer diameter of the second sealing ring is smaller than the inner diameter of the third sealing ring. The sealing of the connection between the third connecting pipe 7 and the shell 1 is ensured by the setting of the second sealing ring and the third sealing ring.

[0085] In this embodiment, preferably, both the first joint 6 and the second joint 5 are pagoda joints.

[0086] In this embodiment, it is more preferred that one end of the first connecting tube 15 is a pagoda mouth (matching the inflow channel 13), and the shape of the other end needs to match the cross-sectional shape of the inner wall of the left atrium in a natural physiological state. In this embodiment, the end of the first connecting tube 15 inserted into the left atrium is designed with a D-shaped convex ring. This can ensure that after the first connecting tube 15 is inserted into the left atrium, the shape of the left atrium does not change, so that the shape of the mitral valve ring and the mitral valve does not change, thereby ensuring the accuracy of the simulation.

[0087] In this embodiment, it is more preferred that one end of the second connecting tube 16 is a pagoda mouth (matching the outflow channel 14), and the other end is designed according to the shape of the aortic valve and the aortic sinus (in order to match different pig hearts, this design has different sizes). In this embodiment, three claws are provided at the end of the second connecting tube 16. These three claws correspond to the three aortic sinuses one by one, and the claws match the shape and size of the corresponding aortic sinuses. The surface material of the claws is silicone, and silicone has a certain elasticity, which can ensure that after the claws are inserted into the corresponding aortic sinus, they will not affect the physiological morphology of the aortic sinus and the aortic valve, thereby ensuring the accuracy of the simulation.

[0088] It is worth noting that in this embodiment, the inflow channel 13, the outflow channel 14, the first connecting tube 15 and the second connecting tube 16 are all straight tubes, and the inflow channel 13 is coaxial with the first connecting tube 15, and the outflow channel 14 is coaxial with the second connecting tube 16; wherein the inflow channel 13 and the outflow channel 14 are transparent.

[0089] The isolated heart 22 may be a human heart, or a pig heart, a cow heart, a sheep heart, a dog heart, or other heart similar in structure to the human heart.

[0090] Embodiment 2

[0091] This embodiment provides an in vitro left heart quasi-physiological environment simulation method based on an isolated heart, based on the in vitro left heart quasi-physiological environment simulation system based on an isolated heart of Embodiment 1, taking a pig heart as an isolated heart 22 as an example, the method includes the following steps:

[0092] (1) The pig heart is processed, unnecessary blood vessels are trimmed, the aortic root is retained, and the left and right coronary arteries are clamped from the coronary artery root, so that the left heart only forms a circuit of left atrium-left ventricle-aorta without other side branches.

[0093] (2) Fix the first connecting tube 15 with a cable tie so that the first connecting tube 15 is connected to the left atrioventricular opening of the pig heart; fix the second connecting tube 16 with a cable tie so that the second connecting tube 16 is connected to the aortic opening of the pig heart; then, connect the first connecting tube 15 with the inflow channel 13 through a hose, connect the second connecting tube 16 with the outflow channel 14 through a hose, and install the first observation window 3 and the second observation window 4 on the top cover 2, and block other openings so that only one passage between the pig heart and the top cover 2 is left, namely, the inflow channel 13—pig heart (i.e., the isolated heart 22)—outflow channel 14, and check the sealing between the pig heart and the top cover 2; then insert the tip of the pressure probe 10 from the bottom end of the pig heart into the left ventricle of the pig heart, and ensure the sealing between the pressure probe 10 and the pig heart;

[0094] (3) Then, the top cover 2 and the housing 1 are assembled together by screws, and the housing 1, the third connecting pipe 7 and the reciprocating pump 21 are assembled together by screws. The third connecting pipe 7 is pre-filled with a first liquid, wherein the first liquid is triple distilled water. After the third connecting pipe 7 is filled with the first liquid, the exhaust port 8 is sealed with a second plug;

[0095] (4) Assemble the external circulation unit, and then, while ensuring that the pig heart and the top cover 2 are well sealed, connect the simulation device to the external circulation unit through the first joint 6 and the second joint 5 on the top cover 2 (the first joint 6 is connected to the third pipeline 31, and the second joint 5 is connected to the first pipeline 29), so that the circulating liquid can circulate in the passage of the external circulation unit, the inflow channel 13, the first connecting tube 15, the isolated heart 22, the second connecting tube 16, and the external circulation unit;

[0096] (5) Remove the first plug 19, and fill the accommodating cavity with a second liquid through the liquid passage. The second liquid is 0.9% saline. At the same time, keep the cavity pressure measuring interface 20 on the top cover 2 open so that the gas in the accommodating cavity can be discharged through the cavity pressure measuring interface 20. After the accommodating cavity is filled with 0.9% saline, close the cavity pressure measuring interface 20 on the top cover 2 to prevent the saline in the accommodating cavity from leaking through the cavity pressure measuring interface 20.

[0097] (6) Then install the first plug 19, and inject a third liquid into the circulation path formed by the external circulation unit and the pig heart. The third liquid is 0.9% saline. Pressure sensors are installed on the cavity pressure measuring interface 20, the left atrial pressure measuring interface 11, the aorta pressure measuring interface 32, and the left ventricle pressure measuring interface 12 respectively.

[0098] It should be noted that when injecting the third liquid into the circulation passage formed by the external circulation unit and the pig heart, the three-way valve 33 needs to be switched so that the first interface of the three-way valve 33 is connected to the third interface, so that the air in the first container is connected to the external atmosphere, so that when the third liquid is injected, part of the third liquid can enter the second container and the first container. After the injection of the third liquid is completed, the three-way valve 33 is switched so that the second interface of the three-way valve 33 is connected to the third interface to keep the first container 26 in a closed state;

[0099] (7) Start the reciprocating pump 21;

[0100] (8) Perform simulation; record the detection values ​​of each pressure sensor. During the simulation, the movement of the pig heart (i.e., the isolated heart 22) can be directly observed through the shell 1, so that 0.9% saline instead of blood circulates between the pig heart (i.e., the isolated heart 22) and the external circulation unit, making it convenient to observe the movement of the mitral valve through the first observation window 3 and the movement of the aortic valve through the second observation window 4.

[0101] After performing step (7) and before performing step (8), the following steps need to be performed:

[0102] S1. Determine the standard flow value of the system during operation according to the type of simulation experiment to be performed and the guidelines for fluid mechanics performance verification in the international standard ISO 5840;

[0103] Observe the first flow meter 23 to obtain the actual flow value of the extracorporeal left heart near physiological environment simulation system based on the isolated heart, and adjust the output amplitude of the reciprocating pump 21 so that the actual flow value is equal to the standard flow value;

[0104] S2, monitoring the pressure value of the aorta, the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart;

[0105] When the mean aortic pressure and the mean left ventricular pressure of the isolated heart 22 are greater than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the resistance value of the second resistance valve 27 is reduced until the mean aortic pressure and the mean left ventricular pressure of the isolated heart 22 meet the fluid mechanics performance verification guidelines in the international standard ISO 5840; when the mean aortic pressure and the mean left ventricular pressure of the isolated heart 22 are less than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the resistance value of the second resistance valve 27 is increased until the mean aortic pressure and the mean left ventricular pressure of the isolated heart 22 meet the fluid mechanics performance verification guidelines in the international standard ISO 5840;

[0106] When the mean pressure of the aorta of the isolated heart 22 complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, but the floating range of the mean pressure of the aorta of the isolated heart 22 is greater than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, part of the air in the first container is extracted by the gas extraction and injection device until the floating range of the mean pressure of the aorta of the isolated heart 22 complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840; when the mean pressure of the aorta of the isolated heart 22 complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, but the floating range of the mean pressure of the aorta of the isolated heart 22 is less than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, air is injected into the first container by the gas extraction and injection device until the floating range of the mean pressure of the aorta of the isolated heart 22 complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840;

[0107] If the minimum pressure value of the aorta, the minimum pressure value of the left ventricle, and the minimum pressure value of the left atrium of the isolated heart 22 are all higher than the fluid mechanics performance verification guidelines in the international standard ISO 5840, a portion of the third liquid is extracted from the liquid storage container 28 to lower the liquid level in the liquid storage container 28 until the minimum pressure value of the aorta, the minimum pressure value of the left ventricle, and the minimum pressure value of the left atrium of the isolated heart 22 meet the fluid mechanics performance verification guidelines in the international standard ISO 5840; if the minimum pressure value of the aorta, the minimum pressure value of the left ventricle, and the minimum pressure value of the left atrium of the isolated heart 22 are all lower than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the third liquid is continued to be injected into the liquid storage container 28 to raise the liquid level in the liquid storage container 28 until the minimum pressure value of the aorta, the minimum pressure value of the left ventricle, and the minimum pressure value of the left atrium of the isolated heart 22 meet the fluid mechanics performance verification guidelines in the international standard ISO 5840;

[0108] The pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart 22 both meet the guidelines for fluid mechanics performance verification in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart 22 is lower than the guidelines for fluid mechanics performance verification in the international standard ISO 5840, then the resistance value of the first resistance valve 24 is increased until the pressure value of the aorta of the isolated heart 22 meets the guidelines for fluid mechanics performance verification in the international standard ISO 5840; the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart 22 both meet the guidelines for fluid mechanics performance verification in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart 22 is higher than the guidelines for fluid mechanics performance verification in the international standard ISO 5840, then the resistance value of the first resistance valve 24 is reduced until the pressure value of the aorta of the isolated heart 22 meets the guidelines for fluid mechanics performance verification in the international standard ISO 5840;

[0109] S3. Adjust the displacement curve of the piston of the reciprocating pump 21 so that the isolated heart 22 is driven in a manner consistent with the law of ventricular volume change during the heartbeat cycle of a healthy person. The law of ventricular volume change during the heartbeat cycle of a healthy person is common knowledge in the art and will not be elaborated on.

[0110] It is worth noting that the reciprocating pump 21 in this embodiment adopts a piston pump. When adjusting the displacement curve of the piston of the reciprocating pump 21 in step S3, care should be taken to ensure that the output amplitude of the reciprocating pump 21 remains unchanged to keep the actual flow value of the system equal to the standard flow value.

[0111] Since different isolated hearts 22 have different sizes and wall thicknesses, it is necessary to design the displacement curve of the piston of the reciprocating pump 21 for different isolated hearts 22 and determine the size of the compliance; during the simulation process, when the physiological saline in the external circulation unit, the inflow channel 13, the first connecting tube 15, the isolated heart 22, the second connecting tube 16, and the passage of the external circulation unit enters the second container 25, it can also partially enter the first container 26. Since the first container 26 is closed, the air in the first container 26 is compressed, and the compressed air gives a reaction force to the physiological saline. Therefore, the design of the first container 26 can well simulate the compliance in the systemic circulation; during the simulation process, the size of the circulation resistance can also be adjusted by manually adjusting the first resistance valve 24 and the second resistance valve 27.

[0112] In the optional scheme of the present embodiment, it is more preferred that, before performing step (1), firstly, in the simulation software, physical simulation models of the isolated heart 22 to be simulated and the in vitro left heart near physiological environment simulation system based on the isolated heart are established, the physical simulation model of the isolated heart 22 to be simulated is called a heart model, and the physical simulation model of the in vitro left heart near physiological environment simulation system based on the isolated heart is called a system model; the size of the heart model matches the size of the isolated heart 22 to be simulated, and the size of the system model is determined according to the physiological blood vessel diameter, blood vessel compliance and liquid storage capacity of the organism where the isolated heart 22 to be simulated is located;

[0113] Then, the left atrioventricular orifice of the heart model is connected to the first connecting tube 15 of the system model, the aorta orifice of the heart model is connected to the second connecting tube 16 of the system model, and the heart model is placed in the housing 1 of the simulation component of the system model;

[0114] The extracorporeal left heart quasi-physiological environment simulation system based on an isolated heart is simulated by simulation software to determine the actual size of each part in the extracorporeal left heart quasi-physiological environment simulation system based on an isolated heart; then the actual parts of the extracorporeal left heart quasi-physiological environment simulation system based on an isolated heart are manufactured based on the determined size, and assembled after the manufacturing is completed.

[0115] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An in vitro left heart near-physiological environment simulation system based on an isolated heart, characterized in that: include: A simulation component, which includes a shell, a top cover and a reciprocating pump. The shell is transparent, and a accommodating chamber is arranged in the shell, and the accommodating chamber is used to place an isolated heart. The top surface of the shell is provided with a first opening, and one side of the shell is provided with a second opening. The bottom of the shell is provided with a liquid passage, and a first plug is detachably installed at the liquid passage; the top cover is sealed with the top surface of the shell, and the first opening is located directly below the top cover, and the top cover includes a top plate and an inclined plate; an inflow channel and a first joint connected to the inflow channel are fixedly provided on the top plate, and an outflow channel and a second joint connected to the outflow channel are fixedly provided on the inclined plate; an end of the inflow channel close to the accommodating chamber is used to connect to the isolated heart through a first connecting pipe. The left atrium and ventricle of the isolated heart are connected, one end of the outflow channel close to the accommodating chamber is used to communicate with the aorta on the isolated heart through the second connecting tube, and the top cover is also detachably mounted with a first observation window and a second observation window, the first observation window is opposite to the end of the inflow channel away from the accommodating chamber, and the second observation window is opposite to the end of the outflow channel away from the accommodating chamber; the liquid inlet and the liquid outlet of the reciprocating pump are respectively sealedly connected to the first end of the third connecting tube, the second end of the third connecting tube is sealedly connected to the side wall of the shell, and the third connecting tube is opposite to the second opening, and an isolation membrane is provided at the second opening, the isolation membrane isolates the third connecting tube from the accommodating chamber, and the area of ​​the isolation membrane is larger than the area of ​​the second opening; An external circulation unit, the external circulation unit includes a first flow meter, a first resistance valve, a compliance component, a second resistance valve, a liquid storage container and a second flow meter, the compliance component includes an injection and exhaust device, a three-way valve, a first container and a second container distributed from top to bottom, the bottom end of the first container is connected to the second container, the first container is sealed, one end of the second container is connected to the second joint through a first pipeline, and the other end is connected to the liquid storage container through a second pipeline, the top of the first container is connected to the first interface of the three-way valve, the vent of the injection and exhaust device is connected to the second interface of the three-way valve, the third interface of the three-way valve is connected to the atmosphere, the injection and exhaust device is used to evacuate or inject air into the first container; the top of the liquid storage container is open, and the liquid storage container is also connected to the first joint through a third pipeline, the first flow meter and the first resistance valve are respectively arranged on the first pipeline, the second resistance valve is arranged on the second pipeline, and the second flow meter is arranged on the third pipeline.

2. The in vitro left heart near-physiological environment simulation system based on an isolated heart according to claim 1, characterized in that: The angle between the top plate and the inclined plate is a first angle, the angle between the annular plane of the aortic valve and the annular plane of the mitral valve in the isolated heart is a second angle, and the first angle is equal to the second angle.

3. The in vitro left heart near-physiological environment simulation system based on an isolated heart according to claim 1, characterized in that: The shell is in a polyhedral shape; the isolation membrane is sealed and connected to the shell; the first joint and the second joint both adopt pagoda joints.

4. The in vitro left heart near-physiological environment simulation system based on an isolated heart according to claim 1, characterized in that: The top cover is also provided with a cavity pressure measuring interface, and the cavity pressure measuring interface is used to install a pressure sensor; the cavity pressure measuring interface is communicated with the accommodating cavity; The inclined plate is provided with an aortic pressure measuring interface which is in communication with the outflow channel, and the aortic pressure measuring interface is used for installing a pressure sensor.

5. The in vitro left heart near-physiological environment simulation system based on an isolated heart according to claim 1, characterized in that: The top cover is also provided with a left atrial pressure measuring interface, and the left atrial pressure measuring interface is used to install a pressure sensor; the left atrial pressure measuring interface is communicated with the inflow channel.

6. The in vitro left heart near-physiological environment simulation system based on an isolated heart according to claim 1, characterized in that: The top cover is also provided with a left ventricular pressure measuring interface, and the left ventricular pressure measuring interface is used to install a pressure sensor; it also includes a left ventricular pressure measuring assembly, and the left ventricular pressure measuring assembly includes a connecting hose and a pressure measuring head. The pressure measuring head is in the shape of a hollow cylinder, one end of the connecting hose is sealedly connected to the left ventricular pressure measuring interface, and the other end is sealedly connected to one end of the pressure measuring head. The other end of the pressure measuring head is pointed and provided with a plurality of openings, and the end of the pressure measuring head away from the connecting hose is used for inserting into the left ventricle of the isolated heart.

7. The in vitro left heart near-physiological environment simulation system based on an isolated heart according to claim 1, characterized in that: An exhaust interface is provided at the top end of the third connecting pipe, and a second plug is detachably installed at the exhaust interface.

8. The in vitro left heart near-physiological environment simulation system based on an isolated heart according to claim 1, characterized in that: A first sealing ring is sandwiched between the top cover and the shell, a second sealing ring and a third sealing ring are sandwiched between the third connecting pipe and the shell, and the outer diameter of the second sealing ring is smaller than the inner diameter of the third sealing ring.

9. A method for simulating an in vitro left heart near-physiological environment based on an isolated heart, characterized in that: The in vitro left heart near-physiological environment simulation system based on an isolated heart according to any one of claims 1 to 8 comprises the following steps: (1) The isolated heart is processed, unnecessary blood vessels are trimmed, the aortic root is retained, and the left and right coronary arteries are clamped from the coronary artery root, so that the left heart of the isolated heart forms a left atrium-left ventricle-aorta circuit without other side branches; (2) Fixing the first connecting tube with a cable tie so that the first connecting tube is connected to the left atrioventricular orifice of the isolated heart; fixing the second connecting tube with a cable tie so that the second connecting tube is connected to the aortic orifice of the isolated heart; connecting the first connecting tube with the inflow channel through a hose, connecting the second connecting tube with the outflow channel through a hose, and installing the first observation window and the second observation window on the top cover so that a passage of inflow channel-isolated heart-outflow channel is formed between the isolated heart and the top cover, and checking the sealing of the isolated heart and the top cover; (3) Assembling the top cover and the housing by screws, and assembling the housing, the third connecting pipe and the reciprocating pump by screws, and pre-filling the third connecting pipe with the first liquid; (4) Assemble the external circulation unit and ensure that the first pipeline is connected to the second joint and the third pipeline is connected to the first joint; (5) removing the first plug and filling the accommodating cavity with the second liquid through the liquid passage; (6) installing a first plug and injecting a third liquid into the passage of the external circulation unit; (7) starting the reciprocating pump; (8) Perform simulation.

10. The method for simulating an in vitro left heart near-physiological environment based on an isolated heart according to claim 9, characterized in that: After performing step (7) and before performing step (8), the following steps need to be performed: S1. Determine the standard flow value of the system during operation according to the type of simulation experiment to be performed and the guidelines for fluid mechanics performance verification in the international standard ISO 5840; Observe the first flow meter to obtain the actual flow value of the isolated heart-based extracorporeal left heart near-physiological environment simulation system, and adjust the output amplitude of the reciprocating pump so that the actual flow value is equal to the standard flow value; S2, monitoring the pressure value of the aorta, the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart; When the mean aortic pressure and the mean left ventricular pressure of the isolated heart are greater than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the resistance value of the second resistance valve is reduced until the mean aortic pressure and the mean left ventricular pressure of the isolated heart meet the fluid mechanics performance verification guidelines in the international standard ISO 5840; when the mean aortic pressure and the mean left ventricular pressure of the isolated heart are less than the fluid mechanics performance verification guidelines in the international standard ISO 5840, the resistance value of the second resistance valve is increased until the mean aortic pressure and the mean left ventricular pressure of the isolated heart meet the fluid mechanics performance verification guidelines in the international standard ISO 5840; When the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, but the floating range of the mean pressure of the aorta of the isolated heart is greater than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, part of the air in the first container is extracted by means of an air extraction and injection device until the floating range of the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840; When the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, but the floating range of the mean pressure of the aorta of the isolated heart is less than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, air is injected into the first container by means of an air extraction and injection device until the floating range of the mean pressure of the aorta of the isolated heart complies with the guidelines for verification of fluid mechanics performance in the international standard ISO 5840; If the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart are all higher than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, part of the third liquid is extracted from the liquid storage container to lower the liquid level in the liquid storage container until the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart meet the guidelines for verification of fluid mechanics performance in the international standard ISO 5840; if the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart are all lower than the guidelines for verification of fluid mechanics performance in the international standard ISO 5840, the third liquid is continuously injected into the liquid storage container to raise the liquid level in the liquid storage container until the minimum pressure value of the aorta, the minimum pressure value of the left ventricle and the minimum pressure value of the left atrium of the isolated heart meet the guidelines for verification of fluid mechanics performance in the international standard ISO 5840; If the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart both comply with the guidelines for fluid mechanics performance verification in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart is lower than the guidelines for fluid mechanics performance verification in the international standard ISO 5840, then the resistance value of the first resistance valve is increased until the pressure value of the aorta of the isolated heart complies with the guidelines for fluid mechanics performance verification in the international standard ISO 5840; If the pressure value of the left ventricle and the pressure value of the left atrium of the isolated heart both comply with the guidelines for fluid mechanics performance verification in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart is higher than the guidelines for fluid mechanics performance verification in the international standard ISO 5840, then the resistance value of the first resistance valve is reduced until the pressure value of the aorta of the isolated heart complies with the guidelines for fluid mechanics performance verification in the international standard ISO 5840; S3. Adjust the displacement curve of the piston of the reciprocating pump so that the isolated heart is driven in a manner consistent with the law of ventricular volume change during the heartbeat cycle of a healthy person.

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