In-vitro left heart near physiological environment simulation system and method based on isolated heartTechnical Field
The invention relates to the technical field of medical equipment, in particular to an in-vitro left heart near physiological environment simulation system and method based on an isolated heart.
Background
In the design and verification process of the implantation intervention medical apparatus, in-vitro evaluation plays a vital role. In particular, for cardiac implants such as interventional prosthetic valves, mitral valve annuloplasty rings, ventricular septum occluders, blood pumps, etc., an in vitro near-physiological simulator capable of simulating a complex biomechanical environment of the heart is needed when evaluating parameters such as their function, biomechanical properties, and damage mechanism.
In order to accurately simulate the complex motion of the heart's myocardium and its subvalvular structures, as well as the flow fields within the ventricles, existing simulation methods generally employ the following approaches:
(1) The isolated animal heart is driven, and the isolated heart is utilized for simulation, especially the pig heart is the most approximate to the human heart due to the anatomical structure of the pig heart, so that the method is the first choice.
(2) 3D printing of heart model the heart model is manufactured by 3D printing technology, is easy to integrate with the pulsation leveling platform, but is difficult to completely replicate the biomechanics of the heart.
(3) And the polyvinyl alcohol pouring heart model is formed by pouring a polyvinyl alcohol material, is convenient to integrate with a pulsation leveling platform, and has limitation in simulating biomechanical characteristics of the heart.
To drive the dynamic motion of the heart model, two different pressurization modes are generally used:
① Internal pressurization by connecting a reciprocating pump to the heart chamber through a hollow connector at the apex of the heart, periodically injecting/withdrawing fluid into/out of the left ventricle to simulate heart motion. This pressurization is characterized by the fact that the fluid in the reciprocating pump participates in the systemic circulation, but the change in ventricular volume is opposite to the physiological state.
② External pressurization is a method in which a heart model is placed in a container filled with liquid, a closed space is formed by vacuum technology, and the liquid is periodically injected into/pumped out of the container by a reciprocating pump so as to drive the ventricular wall to move. In this way, the fluid in the reciprocating pump does not participate in the systemic circulation and the change in ventricular volume is consistent with physiological conditions.
Although the above-described methods can simulate the dynamic process of the heart to some extent, there are some key issues:
1) An isolated animal heart model, which can better simulate the biomechanics of the heart, but lacks a device which can keep the structure and the function of the aortic valve and the mitral valve of the heart and is convenient to be connected with a pulsating flow platform;
2) Although the external pressurizing mode can simulate physiological ventricular volume change, the fixation of the mitral valve annulus and the aortic valve annulus caused by the fixation of the apex and the fundus is not consistent with the physiological condition;
3) Observation of valve movement in the prior art the observation of valve movement is primarily dependent on an endoscope, which requires additional branching and complicated installation procedures.
The above-described technical problems indicate that there is a strong need in the market for an improved in vitro near-physiological simulation device for the heart to more accurately simulate the physiological motion of the heart, while simplifying the valve motion observation procedure.
Disclosure of Invention
The invention aims to provide an in-vitro left heart near physiological environment simulation system and method based on an isolated heart, which are used for solving the problems in the prior art, realizing in-vitro left heart near physiological environment simulation and facilitating observation of valve movement.
In order to achieve the above object, the present invention provides the following solutions:
the invention provides an in vitro left heart near physiological environment simulation system based on an isolated heart, which comprises the following components:
The device comprises a simulation assembly, a top cover and a reciprocating pump, wherein the simulation assembly comprises a shell, a top cover and a reciprocating pump, the shell is transparent, a containing cavity is arranged in the shell, the containing cavity is used for placing a separated heart, a first opening is arranged on the top surface of the shell, a second opening is arranged on one side of the shell, a liquid through hole is arranged at the bottom of the shell, a first plug is detachably arranged at the liquid through hole, the top cover is in sealing connection with the top surface of the shell, the first opening is positioned under the top cover, the top cover comprises a top plate and an inclined plate, an inflow channel and a first connector communicated with the inflow channel are fixedly arranged on the top plate, a second connector communicated with the outflow channel are fixedly arranged on the inclined plate, one end of the inflow channel, which is close to the containing cavity, is used for being communicated with a left room of the separated heart through a first connecting pipe, one end of the outflow channel, which is close to the containing cavity, is used for being communicated with an opening on the separated heart through a second connecting pipe, the top cover, a viewing window is detachably arranged on the top cover, a first connecting pipe is also is in sealing connection with the top cover, a second viewing window is arranged right opposite to the first connecting pipe, a second connecting pipe is arranged at the side of the side wall, a first connecting pipe is opposite to the side wall, a first connecting pipe is far away from the first connecting pipe, a second sealing membrane is arranged at the side of the side wall, and a first sealing membrane is far from the side sealing membrane, and a third connecting membrane, and a sealing membrane, and a second sealing membrane is far from the side sealing membrane;
The external circulation unit comprises a first flowmeter, a first resistance valve, a compliance assembly, a second resistance valve, a liquid storage container and a second flowmeter, wherein the compliance assembly comprises an air injection and exhaust device, a three-way valve, a first container and a second container which are distributed from top to bottom, the bottom end of the first container is communicated with the second container, the first container is airtight, one end of the second container is communicated with the second connector through a first pipeline, the other end of the second container is communicated with the liquid storage container through a second pipeline, the top end of the first container is communicated with a first interface of the three-way valve, a vent of the air injection and exhaust device is communicated with a second interface of the three-way valve, a third interface of the three-way valve is communicated with the atmosphere, the air injection and exhaust device is used for exhausting or injecting air into the first container, the top end of the liquid storage container is opened, the liquid storage container is also connected with the first connector through a third pipeline, the first flowmeter 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 resistance valve is arranged on the second pipeline.
Preferably, the included angle between the top plate and the inclined plate is a first included angle, the included angle between the annular plane of the aortic valve and the annular plane of the mitral valve in the isolated heart is a second included angle, and the first included angle is equal to the second included angle.
Preferably, the shell is polyhedral, the isolating membrane is connected with the shell in a sealing way, and the first connector and the second connector are both pagoda connectors.
Preferably, the top cover is further provided with a cavity pressure measuring interface, the cavity pressure measuring interface is used for installing a pressure sensor, and the cavity pressure measuring interface is communicated with the accommodating cavity.
Preferably, the top cover is also provided with a left atrium pressure measuring interface which is used for installing a pressure sensor, and the left atrium pressure measuring interface is communicated with the inflow channel;
The inclined plate is provided with an aortic pressure measuring interface communicated with the outflow channel, and the aortic pressure measuring interface is used for installing a pressure sensor.
Preferably, the top cover is further provided with a left ventricular pressure measuring interface, the left ventricular pressure measuring interface is used for installing a pressure sensor, the device further comprises a left ventricular pressure measuring assembly, the left ventricular pressure measuring assembly comprises a connecting hose and a pressure measuring head, the pressure measuring head is hollow and cylindrical, one end of the connecting hose is in sealing connection with the left ventricular pressure measuring interface, the other end of the connecting hose is in sealing connection with one end of the pressure measuring head, the other end of the pressure measuring head is pointed and is provided with a plurality of openings, and one end, far away from the connecting hose, of the pressure measuring head is used for being inserted into a left ventricle of the isolated heart.
Preferably, an exhaust port is arranged at the top end of the third connecting pipe, and a second plug is detachably arranged at the exhaust port.
Preferably, a first sealing ring is clamped between the top cover and the shell, a second sealing ring and a third sealing ring are clamped 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.
The invention also provides an in-vitro left heart near physiological environment simulation method based on the isolated heart, which is based on the in-vitro left heart near physiological environment simulation system based on the isolated heart and comprises the following steps:
(1) The isolated heart is processed, unnecessary blood vessels are trimmed, the root of an aorta is reserved, and left and right coronary arteries are clamped from the root of the coronary artery, so that the left heart of the isolated heart forms a left atrium-left ventricle-aorta loop without other side branches;
(2) The first connecting pipe is communicated with the left atrial opening of the isolated heart by using a binding belt, the second connecting pipe is communicated with the aortic opening of the isolated heart by using a binding belt, the first connecting pipe is communicated with the inflow channel by using a hose, the second connecting pipe is communicated with the outflow channel by using a hose, the first observation window and the second observation window are arranged on the top cover, a passage of the inflow channel-the isolated heart-the outflow channel is formed between the isolated heart and the top cover, and the tightness of the isolated heart and the top cover is checked;
(3) Assembling the top cover and the shell through screws, assembling the shell, the third connecting pipe and the reciprocating pump through screws, and filling first liquid into the third connecting pipe in advance;
(4) Assembling the external circulation unit and ensuring that the first pipeline is communicated with the second joint and the third pipeline is communicated with the first joint;
(5) Removing the first plug, and filling the accommodating cavity with the second liquid through the liquid port;
(6) Installing a first plug and injecting a third liquid into a passage of the external circulation unit;
(7) Starting the reciprocating pump;
(8) Simulation was performed.
Preferably, after step (7) is performed, before step (8) is performed, the following steps are required:
s1, determining a standard flow value when a system operates according to the type of a simulation experiment to be performed and a fluid mechanical property verification guiding principle in the international standard ISO 5840;
Observing the first flowmeter to obtain an actual flow value of the in-vitro left heart near-physiological environment simulation system based on the isolated heart, and enabling the actual flow value to be equal to the standard flow value by adjusting the output amplitude of the reciprocating pump;
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 value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart are larger than the fluid mechanical property verification guiding principle in the international standard ISO 5840, the resistance value of the second resistance valve is reduced until the mean value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart accord with the fluid mechanical property verification guiding principle in the international standard ISO 5840, and when the mean value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart are smaller than the fluid mechanical property verification guiding principle in the international standard ISO 5840, the resistance value of the second resistance valve is increased until the mean value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart accord with the fluid mechanical property verification guiding principle in the international standard ISO 5840;
When the pressure average value of the aorta of the isolated heart accords with the fluid mechanical property verification guide principle in the international standard ISO 5840, but the floating range of the pressure average value of the aorta of the isolated heart is larger than the fluid mechanical property verification guide principle in the international standard ISO 5840, pumping part of air in the first container through a pumping and air injecting device until the floating range of the pressure average value of the aorta of the isolated heart accords with the fluid mechanical property verification guide principle in the international standard ISO 5840, and when the pressure average value of the aorta of the isolated heart accords with the fluid mechanical property verification guide principle in the international standard ISO 5840, but the floating range of the pressure average value of the aorta of the isolated heart is smaller than the fluid mechanical property verification guide principle in the international standard ISO 5840, injecting air into the first container through the pumping and air injecting device until the floating range of the pressure average value of the aorta of the isolated heart accords with the fluid mechanical property verification guide principle in the international standard ISO 5840;
The minimum value of the pressure value of the aorta of the isolated heart, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium are all higher than the fluid mechanical property verification guide principle in the international standard ISO 5840, then part of third liquid is pumped from the liquid storage container, so that the liquid level in the liquid storage container is reduced until the minimum value of the pressure value of the aorta of the isolated heart, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium conform to the fluid mechanical property verification guide principle in the international standard ISO 5840, and the minimum value of the pressure value of the aorta of the isolated heart, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium are all lower than the fluid mechanical property verification guide principle in the international standard ISO 5840, and the third liquid is continuously injected into the liquid storage container until the liquid level in the liquid storage container is increased until the minimum value of the pressure value of the aorta of the isolated heart, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium conform to the fluid mechanical property verification guide principle 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 both accord with the fluid mechanical property verification guide principle in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart is lower than the fluid mechanical property verification guide principle in the international standard ISO 5840, the resistance value of the first resistance valve is increased until the pressure value of the aorta of the isolated heart accords with the fluid mechanical property verification guide principle in the international standard ISO 5840, the pressure value of the left ventricle of the isolated heart and the pressure value of the left atrium both accord with the fluid mechanical property verification guide principle in the international standard ISO 5840, but the pressure value of the aorta of the isolated heart is higher than the fluid mechanical property verification guide principle in the international standard ISO 5840, and the resistance value of the first resistance valve is reduced until the pressure value of the aorta of the isolated heart accords with the fluid mechanical property verification guide principle in the international standard ISO 5840;
and S3, adjusting a driving curve of the reciprocating pump, so that the isolated heart is driven in a mode conforming to the change rule of the heart chamber volume in the heart cycle of a healthy person.
Compared with the prior art, the invention has the following technical effects:
The in-vitro left heart near physiological environment simulation system and method based on the isolated heart can realize dynamic simulation of the in-vitro left heart near physiological environment, facilitate observation of valve movement, provide a near physiological in-vitro test environment for the cardiovascular implantation interventional medical instrument, and provide a way for researching the influence of the cardiovascular implantation interventional medical instrument on valve movement and left heart movement.
Furthermore, in the simulation process, the isolated heart is placed in the accommodating cavity, the accommodating cavity is filled with liquid, the isolated heart is not fixed, the physiological motion of the isolated heart can be simulated more accurately, the motion of the mitral valve can be observed conveniently through the first observation window, and the motion of the aortic valve can be observed conveniently through the second observation window.
Furthermore, the shell is transparent and polyhedral, so that the motion of the isolated heart can be conveniently observed from different angles, and the real-time three-dimensional motion measurement of the ventricular wall can be conveniently carried out.
Furthermore, the inflow channel and the outflow channel are transparent, so that the flow of circulating liquid can be conveniently observed.
Furthermore, the invention can realize the technical effects of in-vitro left heart near-physical pathological simulation (hypertension, hypotension, heart failure, and the like) under various conditions (such as hypertension, hypotension, heart failure, and the like) by adjusting the resistance of the compliance cavity, the first resistance valve, the resistance of the second resistance valve, the liquid level of the liquid storage cavity, the displacement curve of the piston, and the like.
Further, the second flowmeter is capable of measuring a flow rate of the liquid flowing back into the liquid storage container from the mitral valve position of the isolated heart when the mitral valve is closed during normal circulation of the circulation loop formed by the left heart of the isolated heart and the external circulation unit.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of the in vitro left heart near physiological environment simulation system based on an isolated heart;
FIG. 2 is a schematic diagram of a portion of a simulation assembly in an in vitro left heart near physiological environment simulation system based on an isolated heart according to the present invention;
FIG. 3 is a schematic diagram of a part of the simulation assembly in the in vitro left heart near physiological environment simulation system based on the isolated heart;
FIG. 4 is a schematic diagram of the structure of a first connection tube in the in vitro left heart near physiological environment simulation system based on an isolated heart according to the present invention;
FIG. 5 is a schematic diagram of the structure of a second connection tube in the in vitro left heart near physiological environment simulation system based on the isolated heart of the present invention;
FIG. 6 is a schematic diagram of a third connection tube in an in vitro left heart near physiological environment simulation system based on an isolated heart according to the present invention;
FIG. 7 is a schematic diagram of the housing in the in vitro left heart near physiological environment simulation system based on the isolated heart of the present invention;
FIG. 8 is a schematic diagram III of a portion of a simulation assembly in an in vitro left heart near physiological environment simulation system based on an isolated heart according to the present invention;
FIG. 9 is a schematic diagram of a portion of a simulation assembly in an in vitro left heart near physiological environment simulation system based on an isolated heart according to the present invention;
FIG. 10 is a schematic diagram showing a part of the simulation components in the in vitro left heart near physiological environment simulation system based on the isolated heart;
FIG. 11 is a schematic diagram of a portion of a simulation assembly in an in vitro left heart near physiological environment simulation system based on an isolated heart according to the present invention;
In the figure, 1, a shell, 2, a top cover, 3, a first observation window, 4, a second observation window, 5, a second connector, 6, a first connector, 7, a third connecting pipe, 8, an exhaust port, 9, a connecting hose, 10, a pressure measuring head, 11, a left atrium pressure measuring port, 12, a left ventricle pressure measuring port, 13, an inflow channel, 14, an outflow channel, 15, a first connecting pipe, 16, a second connecting pipe, 17, a first opening, 18, a second opening, 19, a first plug, 20, a cavity pressure measuring port, 21, a reciprocating pump, 22, an isolated heart, 23, a first flowmeter, 24, a first resistance valve, 25, a second container, 26, a first container, 27, a second resistance valve, 28, a liquid storage container, 29, a first pipeline, 30, a second pipeline, 31, a third pipeline, 32, an aortic interface, 33, a three-way valve, 34, an air injection and exhaust device, 35, a second flowmeter.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention aims to provide an in-vitro left heart near physiological environment simulation system and method based on an isolated heart, which are used for solving the problems in the prior art, realizing in-vitro left heart near physiological environment simulation and simultaneously facilitating observation of valve movement.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
Example 1
As shown in fig. 1 to 11, the present embodiment provides an in vitro left heart near physiological environment simulation system based on an isolated heart, including:
The simulation assembly comprises a shell 1, a top cover 2 and a reciprocating pump 21, wherein the shell 1 is transparent, a containing cavity is arranged in the shell 1 and used for containing a separated heart 22, a first opening 17 is formed in the top surface of the shell 1, a second opening 18 is formed in one side of the shell 1, a liquid through hole is formed in the bottom of the shell 1, and a first plug 19 is detachably arranged at the liquid through hole; a top cover 2 hermetically connected with the top surface of the housing 1, the first opening 17 being located right below the top cover 2, the top cover 2 including a top plate and an inclined plate; an inflow channel 13 and a first joint 6 communicated with the inflow channel 13 are fixedly arranged on the top plate, an outflow channel 14 and a second joint 5 communicated with the outflow channel 14 are fixedly arranged on the inclined plate, one end of the inflow channel 13 close to the accommodating cavity is communicated with a left atrial chamber of the isolated heart 22 through a first connecting pipe 15, one end of the outflow channel 14 close to the accommodating cavity is communicated with an aortic orifice on the isolated heart 22 through a second connecting pipe 16, a first observation window 3 and a second observation window 4 are detachably arranged on the top cover 2, the first observation window 3 is opposite to one end of the inflow channel 13 far from the accommodating cavity, the second observation window 4 is opposite to one end of the outflow channel 14 far from the accommodating cavity;
The external circulation unit comprises a first flowmeter 23, a first resistance valve 24, a compliance assembly, a second resistance valve 27, a liquid storage container 28 and a second flowmeter 35, wherein the compliance assembly comprises an air injection and exhaust device 34, a three-way valve 33, a first container 26 and a second container 25 which are distributed from top to bottom, the bottom end of the first container 26 is communicated with the second container 25, the first container 26 is sealed, one end of the second container 25 is communicated with the second joint 5 through a first pipeline 29, the other end of the second container 25 is communicated with the liquid storage container 28 through a second pipeline 30, the top end of the first container 26 is communicated with a first interface of the three-way valve 33, a vent of the air injection and exhaust device 34 is communicated with a second interface of the three-way valve 33, a third interface of the three-way valve 33 is communicated with the atmosphere, and the air injection and exhaust device 34 is used for exhausting or injecting air into the first container 26; in this embodiment, the injection and exhaust device 34 adopts a syringe, in practical application, the injection and exhaust device 34 may adopt another type of injection and exhaust device 34 such as an air bag, when the first container 26 needs to be pumped, the three-way valve 33 is switched so that the second port of the three-way valve 33 is communicated with the third port, then the handle of the syringe (i.e. the injection and exhaust device 34) is pressed, then the three-way valve 33 is switched so that the first port of the three-way valve 33 is communicated with the second port, namely the injection and exhaust device 34 is communicated with the first container, then the handle of the syringe is pulled to pump the first container 26 through the syringe, when the first container 26 needs to be pumped, the three-way valve 33 is switched so that the first port of the three-way valve 33 is communicated with the second port, namely the injection and exhaust device 34 is communicated with the first container, then the handle of the syringe is pressed, injecting air into the first container 26 through the injector;
The top end of the liquid storage container 28 is open, the liquid storage container 28 is also connected with the first joint 6 through a 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, 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 for measuring the flow of the circulation loop, and when the circulation loop formed by the left heart of the isolated heart and the external circulation unit circulates normally, part of liquid flows back into the liquid storage container from the mitral valve position of the isolated heart when the mitral valve closes, and the second flowmeter 35 can be used for measuring the flow of the liquid flowing back into the liquid storage container from the position before the mitral valve of the isolated heart.
The reciprocating pump 21 periodically sucks the liquid in the third connecting pipe 7 or discharges the liquid into the third connecting pipe 7 when in operation, so that the volume of the liquid in the third connecting pipe 7 is changed, the isolating membrane is driven to move when the volume of the liquid in the third connecting pipe 7 is changed, the hydraulic pressure in the accommodating cavity is changed by the movement of the isolating membrane, and the isolated heart 22 is contracted and expanded by the change of the hydraulic pressure in the accommodating cavity, so that the near-physiological simulation of the isolated heart 22 is performed.
In this embodiment, it is preferable that the angle between the top plate and the inclined plate is a first angle, the angle between the plane of the annulus of the aortic valve and the plane of the annulus of the mitral valve in the isolated heart 22 is a second angle, and the first angle is equal to the second angle.
In this embodiment, preferably, the housing 1 is polyhedral, and the polyhedral design facilitates erection of a plurality of cameras from different angles to capture heart motion in real time, so as to facilitate in-vitro evaluation.
In this embodiment, preferably, the isolation film is in sealing connection with the casing 1, and the isolation film isolates the liquid in the accommodating cavity in the casing 1 from the liquid in the third connecting pipe 7, so that the liquid in the accommodating wall can be prevented from polluting the liquid pumped by the reciprocating pump 21, the working stability of the reciprocating pump 21 is ensured, and the service life of the reciprocating pump 21 is prolonged.
In this embodiment, preferably, the top cover 2 is further provided with a cavity pressure measuring port 20, a left atrium pressure measuring port 11 and a left ventricle pressure measuring port 12, and the embodiment further comprises a left ventricle pressure measuring component, wherein the cavity pressure measuring port 20, the left atrium pressure measuring port 11 and the left ventricle pressure measuring port 12 are used for installing a pressure sensor, and specifically, the pressure sensor is provided with ports matched with the cavity pressure measuring port 20, the left atrium pressure measuring port 11 and the left ventricle pressure measuring port 12, so that the pressure sensor is conveniently installed on the cavity pressure measuring port 20, the left atrium pressure measuring port 11 or the left ventricle pressure measuring port 12.
The cavity pressure measuring interface 20 is communicated with the accommodating cavity, when the pressure sensor is arranged on the cavity pressure measuring interface 20, the pressure value in the accommodating cavity can be directly measured, the aortic pressure measuring interface 32 communicated with the outflow channel 14 is arranged on the inclined plate, the aortic pressure measuring interface 32 is used for arranging the pressure sensor, and when the pressure measuring device is used, one pressure sensor is usually required to be respectively arranged on the cavity pressure measuring interface 20, the left atrium pressure measuring interface 11, the aortic pressure measuring interface 32 and the left ventricle pressure measuring interface 12, so that the pressure monitoring is convenient.
Since the aortic pressure measurement port 32 communicates with the outflow channel 14 and the outflow channel 14 communicates with the aortic port on the isolated heart 22 through the second connection tube 16, a pressure sensor is installed on the aortic pressure measurement port 32, and thus, the pressure value of the aortic pressure can be directly measured.
The left atrium pressure measuring interface 11 is communicated with the inflow channel 13, and the inflow channel 13 is communicated with the left atrium of the isolated heart 22 through the first connecting pipe 15, so that when the pressure sensor is arranged on the left atrium pressure measuring interface 11, the pressure value in the left atrium of the isolated heart 22 can be directly measured;
The left ventricular pressure measuring assembly comprises a connecting hose 9 and a pressure measuring head 10, wherein the pressure measuring head 10 is in a hollow cylinder shape, one end of the connecting hose 9 is in sealing connection with a left ventricular pressure measuring interface 12, the other end of the connecting hose 9 is in sealing connection with one end of the pressure measuring head 10, the other end of the pressure measuring head 10 is pointed and is provided with a plurality of openings, one end of the pressure measuring head 10, which is far away from the connecting hose 9, is used for being inserted into a left ventricle of the isolated heart 22, and since the tip of the pressure measuring head 10 is inserted into the left ventricle, the liquid in the left ventricle can be communicated with the left ventricular pressure measuring interface 12 through the pressure measuring head 10 and the connecting hose 9, when the pressure sensor is arranged on the left ventricular pressure measuring interface 12, the pressure value in the left ventricle of the isolated heart 22 can be directly measured, and the sealing connection between the pressure measuring head 10 and the isolated heart 22 needs to be ensured when the pressure measuring assembly is used, so that the liquid in the left ventricle of the isolated heart 22 can be prevented from leaking from the isolated heart 22 and the pressure measuring head 10.
In this embodiment, preferably, the top end of the third connecting pipe 7 is provided with an exhaust port 8, and the exhaust port 8 is detachably provided with a second plug, and the exhaust port 8 is used for facilitating the discharge of the gas in the third connecting pipe 7 when the third connecting pipe 7 is filled with the liquid, and the exhaust port 8 is plugged by the second plug after the third connecting pipe 7 is filled with the liquid, so as to prevent the liquid in the third connecting pipe 7 from leaking from the exhaust port 8.
The first sealing ring is clamped between the top cover 2 and the shell 1, the sealing performance of the connection between the top cover 2 and the shell 1 is enhanced through the first sealing ring, the third connecting pipe 7 in the embodiment is conical, the second sealing ring and the third sealing ring are clamped between the third connecting pipe 7 and the shell 1, the outer diameter of the second sealing ring is smaller than the inner diameter of the third sealing ring, and the sealing performance of the connection between the third connecting pipe 7 and the shell 1 is ensured through the arrangement of the second sealing ring and the third sealing ring.
In this embodiment, it is preferable that both the first joint 6 and the second joint 5 are pagoda joints.
In this embodiment, preferably, one end of the first connecting tube 15 is a pagoda-shaped orifice (matched with the inflow channel 13), and the shape of the other end is required to be matched with the cross-sectional shape of the inner wall of the left atrium in a natural physiological state, and a D-shaped convex ring is designed at one end of the first connecting tube 15 inserted into the left atrium in this embodiment, so that the shape of the left atrium is not changed after the first connecting tube 15 is inserted into the left atrium, so that the shapes of the mitral valve ring and the mitral valve are not changed, and the simulation accuracy is ensured.
In this embodiment, preferably, one end of the second connecting tube 16 is a pagoda-shaped opening (matched with the outflow channel 14), and the other end is designed according to the shape of the aortic valve and the aortic sinus (for matching different pig hearts, the design has different sizes), in this embodiment, the end of the second connecting tube 16 is provided with three claws, the three claws are in one-to-one correspondence with the three aortic sinuses, the claws are matched with the shape and the size of the corresponding aortic sinuses, the surface layer of the claws is made of silica gel, and the silica gel has certain elasticity, so that after the claws are inserted into the corresponding aortic sinuses, the physiological forms of the aortic sinuses and the aortic valve are not affected, and further the simulation accuracy is ensured.
It should be noted that, in the present embodiment, the inflow channel 13, the outflow channel 14, the first connecting pipe 15 and the second connecting pipe 16 are all straight pipes, and the inflow channel 13 is coaxial with the first connecting pipe 15, and the outflow channel 14 is coaxial with the second connecting pipe 16, wherein the inflow channel 13 and the outflow channel 14 are transparent.
The isolated heart 22 may be a human heart, or may be a heart similar in structure to a human heart, such as a pig heart, a cow heart, a sheep heart, or a dog heart.
Example two
The present embodiment provides an in vitro left heart near physiological environment simulation method based on an isolated heart, based on the in vitro left heart near physiological environment simulation system based on an isolated heart of the first embodiment, taking a pig heart as an example of an isolated heart 22, comprising the following steps:
(1) The pig heart is processed, unnecessary blood vessels are trimmed, the aortic root is reserved, and the left and right coronary arteries are clamped from the coronary artery root, so that the left heart only forms a loop of left atrium-left ventricle-aortic artery, and no other side branches are generated.
(2) The method comprises the steps of fixing a first connecting pipe 15 by a binding belt, fixing a second connecting pipe 16 by the binding belt, connecting the second connecting pipe 16 with an aortic orifice of the pig heart, connecting the first connecting pipe 15 with an inflow channel 13 by a hose, connecting the second connecting pipe 16 with an outflow channel 14 by a hose, installing a first observation window 3 and a second observation window 4 on a top cover 2, blocking other openings, and enabling only an inflow channel 13-the pig heart (namely an isolated heart 22) -to flow out of the channel 14 to check the tightness between the pig heart and the top cover 2, and inserting the tip of a pressure measuring head 10 into the left ventricle of the pig heart from the bottom end of the pig heart, and guaranteeing the tightness between the pressure measuring head 10 and the pig heart;
(3) Then the top cover 2 and the shell 1 are assembled through screws, the shell 1, the third connecting pipe 7 and the reciprocating pump 21 are assembled through screws, the third connecting pipe 7 is filled with first liquid in advance, the first liquid adopts three distilled water, and the second plug is used for sealing the exhaust interface 8 after the third connecting pipe 7 is filled with the first liquid;
(4) The external circulation unit is assembled, and then the simulation device is connected with the external circulation unit (the first connector 6 is communicated with the third pipeline 31, the second connector 5 is communicated with the first pipeline 29) through the first connector 6 and the second connector 5 on the top cover 2 under the condition that the good tightness of the pig heart and the top cover 2 is ensured, so that the circulation liquid can circulate in the external circulation unit, the inflow channel 13, the first connecting pipe 15, the isolated heart 22, the second connecting pipe 16 and the passages of the external circulation unit;
(5) The first plug 19 is disassembled, the second liquid is filled into the accommodating cavity through the liquid through hole, the second liquid adopts 0.9% physiological saline, and meanwhile, the cavity pressure measuring port 20 on the top cover 2 is kept open, so that the gas in the accommodating cavity can be discharged through the cavity pressure measuring port 20, and after the accommodating cavity is filled with 0.9% physiological saline, the cavity pressure measuring port 20 on the top cover 2 is closed, and the physiological saline in the accommodating cavity is prevented from leaking through the cavity pressure measuring port 20;
(6) Then the first plug 19 is arranged, and third liquid is injected into a circulation passage formed by the external circulation unit and the pig heart, wherein the third liquid adopts 0.9 percent physiological saline, and pressure sensors are respectively arranged on the cavity pressure measuring interface 20, the left atrium pressure measuring interface 11, the aorta pressure measuring interface 32 and the left ventricle pressure measuring interface 12;
When the third liquid is injected into the circulation path formed by the external circulation unit and the pig heart, the three-way valve 33 needs to be switched so that the first port of the three-way valve 33 is communicated with the third port, and the air in the first container is communicated with the external atmosphere, so that part of the third liquid can enter the second container and the first container when the third liquid is injected, and after the third liquid is injected, the three-way valve 33 is switched so that the second port of the three-way valve 33 is communicated with the third port, so that the first container 26 is kept in a closed state;
(7) Starting the reciprocating pump 21;
(8) The detection values of the pressure sensors are recorded, and the motion of the pig heart (namely the isolated heart 22) can be directly observed through the shell 1 in the simulation process, so that 0.9% physiological saline instead of blood circulates in the pig heart (namely the isolated heart 22) and an external circulation unit, and the motion of the mitral valve can be conveniently observed through the first observation window 3 and the motion of the aortic valve can be conveniently observed through the second observation window 4.
After step (7) is performed, before step (8) is performed, the following steps are required:
s1, determining a standard flow value when a system operates according to the type of a simulation experiment to be performed and a fluid mechanical property verification guiding principle in the international standard ISO 5840;
Observing the first flowmeter 23 to obtain an actual flow value based on an in-vitro left heart near-physiological environment simulation system of the isolated heart, and enabling the actual flow value to be equal to a standard flow value by adjusting the output amplitude of the reciprocating pump 21;
s2, monitoring the pressure value of an aorta, the pressure value of a left ventricle and the pressure value of a left atrium of the isolated heart;
When the mean value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart 22 are larger than the fluid mechanical property verification guiding principle in the international standard ISO 5840, the resistance value of the second resistance valve 27 is reduced until the mean value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart 22 accord with the fluid mechanical property verification guiding principle in the international standard ISO 5840, and when the mean value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart 22 are smaller than the fluid mechanical property verification guiding principle in the international standard ISO 5840, the resistance value of the second resistance valve 27 is increased until the mean value of the aortic pressure and the mean value of the left ventricular pressure of the isolated heart 22 accord with the fluid mechanical property verification guiding principle in the international standard ISO 5840;
When the pressure average value of the aorta of the isolated heart 22 accords with the fluid mechanical property verification guide principle in the international standard ISO 5840, but the floating range of the pressure average value of the aorta of the isolated heart 22 is larger than the fluid mechanical property verification guide principle in the international standard ISO 5840, pumping part of air in the first container through a pumping and injecting device until the floating range of the pressure average value of the aorta of the isolated heart 22 accords with the fluid mechanical property verification guide principle in the international standard ISO 5840, and when the pressure average value of the aorta of the isolated heart 22 accords with the fluid mechanical property verification guide principle in the international standard ISO 5840, but the floating range of the pressure average value of the aorta of the isolated heart 22 is smaller than the fluid mechanical property verification guide principle in the international standard ISO 5840, injecting air into the first container through the pumping and injecting device until the floating range of the pressure average value of the aorta of the isolated heart 22 accords with the fluid mechanical property verification guide principle in the international standard ISO 5840;
If the minimum value of the pressure value of the aorta of the isolated heart 22, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium are all higher than the fluid mechanical property verification guidelines in the international standard ISO 5840, then part of the third liquid is pumped out of the liquid storage container 28 so that the liquid level in the liquid storage container 28 is lowered until the minimum value of the pressure value of the aorta of the isolated heart 22, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium conform to the fluid mechanical property verification guidelines in the international standard ISO 5840, and if the minimum value of the pressure value of the aorta of the isolated heart 22, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium are all lower than the fluid mechanical property verification guidelines in the international standard ISO 5840, the third liquid is continuously injected into the liquid storage container 28 until the minimum value of the pressure value of the aorta of the isolated heart 22, the minimum value of the pressure value of the left ventricle and the minimum value of the pressure value of the left atrium conform to the fluid mechanical property verification guidelines 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 conform to the fluid mechanical property verification guidelines in international standard ISO 5840, but the pressure value of the aorta of the isolated heart 22 is lower than the fluid mechanical property verification guidelines in international standard ISO 5840, the resistance value of the first resistance valve 24 is increased until the pressure value of the aorta of the isolated heart 22 conforms to the fluid mechanical property verification guidelines in international standard ISO 5840, the pressure value of the left ventricle of the isolated heart 22 and the pressure value of the left atrium both conform to the fluid mechanical property verification guidelines in international standard ISO 5840, but the pressure value of the aorta of the isolated heart 22 is higher than the fluid mechanical property verification guidelines in international standard ISO 5840, the resistance value of the first resistance valve 24 is reduced until the pressure value of the aorta of the isolated heart 22 conforms to the fluid mechanical property verification guidelines in international standard ISO 5840;
And S3, adjusting a displacement curve of a piston of the reciprocating pump 21 to drive the isolated heart 22 in a mode conforming to the change rule of the heart chamber volume in the heart cycle of a healthy person, wherein the change rule of the heart chamber volume in the heart cycle of the healthy person is common knowledge in the field, and the redundant description is not required.
It should be noted that, in the present embodiment, the reciprocating pump 21 employs a piston pump, and when the displacement curve of the piston of the reciprocating pump 21 is adjusted in step S3, care should be taken to ensure that the output amplitude of the reciprocating pump 21 is unchanged, so as to keep the actual flow value of the system equal to the standard flow value.
Because of the different sizes and wall thicknesses of the different isolated hearts 22, it is necessary to design the displacement curve of the piston of the reciprocating pump 21 and determine the compliance for the different isolated hearts 22, and during the simulation, when the physiological saline in the external circulation unit, the inflow channel 13, the first connecting pipe 15, the isolated hearts 22, the second connecting pipe 16 and the passage of the external circulation unit enters the second container 25, the physiological saline can also partially enter the first container 26, and because the first container 26 is sealed, the air in the first container 26 is compressed and gives a reaction force to the physiological saline after the air is compressed, the design of the first container 26 can well simulate the compliance in the systemic circulation, and during the simulation, the circulating resistance can also be adjusted by manually adjusting the first resistance valve 24 and the second resistance valve 27.
In the alternative of this embodiment, preferably, before step (1) is performed, firstly, in simulation software, a physical simulation model of the isolated heart 22 to be simulated and a physical simulation model of the isolated heart 22 based on an external left heart near physiological environment simulation system is 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 isolated heart 22 based on the external left heart near physiological environment simulation system is called a system model;
then the left atrioventricular port of the heart model is communicated with a first connecting tube 15 of the system model, the aortic port of the heart model is communicated with a second connecting tube 16 of the system model, and the heart model is placed in the shell 1 of the simulation assembly of the system model;
Simulating the in vitro left heart near physiological environment simulation system based on the isolated heart through simulation software to determine the actual size of each part in the in vitro left heart near physiological environment simulation system based on the isolated heart, and then manufacturing each part in the in vitro left heart near physiological environment simulation system based on the isolated heart based on the actual size, and assembling after manufacturing is completed.
The principles and embodiments of the present invention have been described in detail with reference to specific examples, which are provided herein to facilitate understanding of the principles and embodiments of the present invention and to provide further advantages and practical applications for those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.