Flow ratio automatic adjusting system for VAV-ECMO arteriovenous reflux and adjusting method thereof

Abstract

The application discloses a flow ratio automatic adjusting system for VAV-ECMO arteriovenous reflux, which is used for switching from VA-ECMO or VV-ECMO mode to VAV-ECMO mode, comprising a Y-shaped connecting pipe and a capsule arranged in the Y-shaped connecting pipe, at least one capsule is arranged on the inner wall of each branch pipe of the Y-shaped connecting pipe; a medium output device is used for filling the capsule with medium, so that the capsule deforms, and then the area of the flow passage cross section at the position of the capsule in the branch pipe is changed, and the blood flow rate in the branch pipe is changed; the application also discloses a flow ratio automatic adjusting method for VAV-ECMO arteriovenous reflux, blood flow rates in two branch pipes are collected by an induction module; a control module receives and analyzes the flow rate difference of blood in the two branch pipes, controls the amount of medium filled into the capsule by the medium output device, so that the blood in the two branch pipes finally realizes flow rate matching, dynamic adjustment can be realized, and control precision is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field, and particularly relates to a flow ratio automatic adjusting system for VAV-ECMO arterial-venous reflux and an adjusting method thereof. BACKGROUND

[0002] Extracorporeal Membrane Oxygenation (ECMO) is also called artificial lung, which is a high-level life support technology based on extracorporeal circulation system and artificial heart-lung support. ECMO technology is currently applied more and more widely in clinic, and brings survival hope for patients with severe heart and lung failure, and is therefore regarded as the "ultimate weapon" in the intensive care unit (ICU).

[0003] In clinical application, ECMO is mainly divided into two modes of venous-venous bypass (VV-ECMO) and venous-arterial bypass (VA-ECMO) according to different assisted organs.

[0004] VV-ECMO is used for patients with severe respiratory failure, and is formed by blood drainage through the femoral vein, oxygenation through the membrane lung, and reflux through the jugular vein; as shown in FIG. 1, the extracorporeal circulation is composed of a femoral vein drainage tube and a jugular vein reflux tube. Figure 1 When the patient is in the mode of VV-ECMO, secondary left / right / total heart failure occurs, and the derived mode VAV-ECMO needs to be used on the basis of the original VV-ECMO, as shown in FIG. 2, that is, a femoral artery reflux tube is added for VAV-ECMO treatment. Figure 1

[0005] VA-ECMO is used for patients with severe heart failure and acute myocardial infarction, and is formed by blood drainage through the jugular / femoral vein, oxygenation through the membrane lung, and reflux through the femoral artery; as shown in FIG. 3, the extracorporeal circulation is composed of a venous drainage tube and a jugular vein reflux tube. Figure 1 When the patient is in the mode of VA-ECMO, and there is also lung dysfunction, the patient is prone to have north-south syndrome, and the patient shows upper body hypoxia, and the derived mode VAV-ECMO needs to be used on the basis of the original VV-ECMO, as shown in FIG. 4, that is, a jugular vein reflux tube is added for VAV-ECMO treatment. Figure 1

[0006] VAV-ECMO is formed by blood drainage through the femoral vein, oxygenation through the membrane lung, and reflux through the jugular vein and femoral artery, to simultaneously realize respiratory and circulation support.

[0007] ​​At present, in the VAV-ECMO mode, the pressure difference between the artery and the vein is large, so that when the ECMO backflow occurs, the artery and the vein backflow ratio is not matched, and more proportion of blood will backflow to the vein system, which affects the treatment effect. SUMMARY

[0008] The purpose of the present application is to provide a flow ratio automatic adjusting system for VAV-ECMO artery and vein backflow and an adjusting method thereof, which adopts a Y-shaped connecting pipe, and a capsule is arranged in two branch pipes of the Y-shaped connecting pipe, so that the flow cross section of the two branch pipes can be dynamically changed, and the artery and vein backflow flow ratio can be dynamically adjusted, so as to solve the technical problems existing in the prior art.

[0009] To solve the above technical problems, the present application specifically provides the following technical scheme: a flow ratio automatic adjusting system for VAV-ECMO artery and vein backflow, comprising: a Y-shaped connecting pipe, including one total branch pipe and two branch pipes formed by branching from one end of the total branch pipe; wherein the end of the total branch pipe is used for connecting a vein drainage pipe, and a body oxygenation device is connected in series on the vein drainage pipe; the ends of the two branch pipes are respectively used for connecting a vein backflow pipe and an artery backflow pipe.

[0010] A capsule is arranged on the inner wall of the two branch pipes of the Y-shaped connecting pipe; the capsule is made of a deformable material.

[0011] A medium output device is arranged outside the Y-shaped connecting pipe and is connected in communication with the interiors of a plurality of capsules; the medium output device is used for filling the interior of the capsule with a medium, so that the capsule is deformed, and the area of the flow cross section at the position of the capsule in the branch pipe is changed.

[0012] Two groups of sensing modules are arranged on the inner walls of the ends of the two branch pipes; the sensing modules are used for collecting the speeds of blood flow in the two branch pipes.

[0013] A control module is in communication connection with the sensing modules, receives and analyzes the speeds of blood flow in the two branch pipes; according to the flow rate difference of blood in the two branch pipes, the control module controls the amount of medium filled in the capsule in the interior of the corresponding branch pipe by the medium output device, so that the flow rates of blood in the two branch pipes are matched.

[0014] Further, the capsule in a single branch pipe is provided with a plurality of groups, and the plurality of groups of capsules are alternately arranged at two symmetrical positions along the inner wall of the branch pipe; and the plurality of groups of capsules in a single branch pipe change in volume in sequence.

[0015] Further, the capsule is made of an elastic material, and the volume of the capsule changes correspondingly according to the amount of filled medium.

[0016] Further, the capsule is fixed by the edge position of the elastic film on the inner wall of the branch pipe.

[0017] Further, the inside of the capsule is in a state without medium, and the elastic film is attached to the inner wall of the branch pipe.

[0018] To solve the above technical problems, the application further provides the following technical scheme: a flow ratio automatic adjusting method for VAV-ECMO arterial-venous reflux, based on a flow ratio automatic adjusting system for VAV-ECMO arterial-venous reflux, the specific method is as follows,

[0019] In step 100, the sensing module respectively collects the flow rate signals of the blood in the two branch pipes, and transmits the flow rate signals to the control module.

[0020] In step 200, the control module receives and compares the flow rate signals in the two branch pipes, controls the medium output device to output medium according to the flow rate difference between the two, changes the volume of any one of the capsules in the branch pipe with relatively faster blood flow, and further changes the area of the flow cross section at the position of the capsule in the branch pipe, so that the flow rates of the blood in the two branch pipes are matched.

[0021] Further, in the VAV-ECMO mode, the control module adjusts the amount of medium output by the medium output device in real time according to the blood flow rate signals collected by the sensing module in real time, so as to ensure that the flow rates of the blood in the two branch pipes are matched.

[0022] Further, in step 200, the medium output device sequentially fills the multiple capsules in a single branch pipe with medium.

[0023] During the whole process, only one group of capsules is in a state of being filled with medium, and the remaining capsules are in a state of not being filled with medium.

[0024] Further, the two branch pipes are respectively provided with a first capsule, a second capsule and a third capsule.

[0025] In step 200, the medium output device first fills the first capsule inside the branch pipe with relatively faster blood flow with medium, and the second capsule and the third capsule remain in a state of not being filled with medium; until the flow rates of the blood in the two branch pipes are matched.

[0026] After a fixed time interval, the first capsule uniformly returns to a state of not being filled with medium and remains in a state of not being filled with medium; at the same time, the medium output device fills the second capsule with medium, and the third capsule continues to remain in a state of not being filled with medium; until the flow rates of the blood in the two branch pipes are matched.

[0027] After a fixed time interval, the first capsule continues to remain in the state of not filling the medium; the second capsule uniformly recovers to the state of not filling the medium and remains in the state of not filling the medium; the medium output device fills the medium to the third capsule; until the flow rates of blood in the two branch pipes match;

[0028] After a fixed time interval, the above steps are repeated.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] The present application provides a flow ratio automatic adjusting system for VAV-ECMO arterial-venous reflux, the control module changes the volume of the capsule in the branch pipe with larger flow rate according to the flow rate difference of blood in the two branch pipes of the Y-shaped connecting pipe, changes the flow passage section of the branch pipe, and makes the flow rates of blood in the two branch pipes match.

[0031] Further, the sensing module can collect the real-time flow rates of blood in the two reflux pipes, so that the control module adjusts the flow rates of blood in the two branch pipes in real time, so that the flow rates of blood in the two branch pipes always remain consistent.

[0032] Further, a plurality of capsules are arranged in the branch pipe, and the plurality of capsules are inflated in sequence and at intervals, so as to avoid turbulent flow caused by long-time blood flow through a narrow part (a single capsule is long-term inflated to cause a narrow part at the corresponding position of the capsule in the branch pipe), and thrombosis is easy to form. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can be obtained from the provided drawings without creative labor.

[0034] Figure 1 It is a structural schematic diagram of VAV-ECMO mode;

[0035] Figure 2 It is a structural schematic diagram of the flow ratio automatic adjusting system for VAV-ECMO arterial-venous reflux provided in the present application;

[0036] Figure 3 It is an embodiment of the flow ratio automatic adjusting system for VAV-ECMO arterial-venous reflux.

[0037] The numbers in the drawings represent the following respectively:

[0038] 1-Y-shaped connecting pipe, 11-main branch pipe, 12-branch pipe, 2-bladder, 3-medium output device, 4-hose, 5-sensing module, 6-control module, 7-first solenoid valve, 8-return pipe, 9-second solenoid valve. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] This invention provides a specific implementation of an automatic flow ratio adjustment system for arteriovenous return in VAV-ECMO, including a Y-shaped connecting tube for connecting a venous return tube and an arterial return tube, for switching between VA-ECMO or VV-ECMO mode and VAV-ECMO mode.

[0041] Because of the large pressure difference between arteries and veins, during ECMO recirculation, there will be a mismatch between the ratio of arterial and venous return, with a larger proportion of blood flowing back into the venous system, affecting the treatment effect.

[0042] like Figure 1 As shown, clamping devices are generally used clinically to increase the resistance of venous return tubing in order to roughly match arterial and venous blood return. However, patients' blood pressure varies, especially for critically ill patients, where blood pressure fluctuations are more pronounced. This fixed clamping device cannot dynamically adjust the ratio of arterial to venous return based on blood pressure fluctuations, requiring manual adjustment by medical staff.

[0043] To address the aforementioned problems, this application provides specific embodiments of Y-shaped connecting pipes, such as... Figure 2 As shown:

[0044] The Y-shaped connecting tube 1 includes a main branch tube 11 and two branch tubes 12 formed by branching from one end of the main branch tube 11; wherein, the end of the main branch tube 11 is used to connect to a venous drainage tube, and an extracorporeal oxygenation device is connected in series on the venous drainage tube; the ends of the two branch tubes 12 are respectively used to connect to a venous return tube and an arterial return tube.

[0045] At least one capsule 2 is provided on the inner wall of each of the two branch pipes 12 of the Y-shaped connecting pipe 1; the capsule 2 is made of deformable material.

[0046] The medium output device 3 is located outside the Y-shaped connecting pipe 1 and is in communication with the inside of the capsule 2; the medium output device 3 is used to fill the medium into the inside of the capsule 2, so that the capsule 2 is deformed, and then the area of the flow passage cross section at the position of the capsule 2 in the branch pipe 12 is changed.

[0047] In the embodiment, the volume of the capsule 2 can be changed by filling gas or liquid.

[0048] The air bag has a safety hazard, if it is broken, air leakage into the blood can cause air embolism, and the risk can be avoided if sterile water enters the blood, therefore, in the embodiment, sterile water is preferably used as the filling medium, and the medium output device 3 fills the sterile water into the capsule 2.

[0049] Regarding the capsule 2, the application provides an embodiment as shown in Figure 2

[0050] The capsule 2 is made of an elastic material, preferably a silicone material; according to the amount of the filled medium, the volume of the capsule 2 is changed correspondingly.

[0051] Further, the capsule 2 is fixed at the edge position of the elastic film to the inner wall of the branch pipe 12. If the complete capsule 2 is located in the branch pipe 12, it is easy to cause the blockage of the inside of the branch pipe 12, so that the blood cannot flow.

[0052] The capsule 2 is in a normal state (a state without filling the medium) and is in close contact with the inner wall of the branch pipe 12, that is, the capsule 2 is in a dry state without filling the medium, and does not affect the blood flow rate in the branch pipe 12.

[0053] In the embodiment, the sensing module 5 is provided with two groups, which are respectively arranged on the inner walls of the two end portions of the branch pipes 12; the sensing module 5 is used to collect the blood flow rates in the two branch pipes 12.

[0054] In the embodiment, the sensing module 5 preferably selects a medical flow detector.

[0055] The control module 6 and the sensing module 5 are in communication connection, receive and analyze the blood flow rates in the two branch pipes 12; according to the flow rate difference of the blood in the two branch pipes 12, the control module 6 controls the amount of the medium filled into the capsule 2 in the corresponding branch pipe 12 by the medium output device 3, so that the blood flow rates in the two branch pipes 12 are matched.

[0056] Specifically, if the lung demand of the patient is large, the blood flow in the venous return pipe is larger; if the heart demand of the patient is large, the blood flow in the arterial return pipe is larger.

[0057] ​When blood flows through the stenosis, vortex flow is generated, and cells in the vortex flow are retained for a long time; in addition, the vortex formed will form a new energy impact, which makes a large number of red blood cells deform beyond the limit and be damaged, release adenosine diphosphate (ADP), and promote platelet aggregation; at the same time, when the red blood cells are damaged, thromboplastin is also released, which makes the prothrombin become thrombin, and the platelet aggregation is irreversible. In summary, long-time vortex flow has the risk of thrombosis.

[0058] In order to avoid the above situation, the present application provides a plurality of capsule 2 spacing expansion embodiments, the specific structure as shown in Figure 2

[0059] The capsule 2 in a single branch pipe 12 is provided with a plurality of groups, and the plurality of groups of capsule 2 are alternately arranged along the two symmetrical positions on the inner wall of the branch pipe 12. In this embodiment, three groups of capsule 2 are arranged in a single branch pipe 12.

[0060] And the volume of the plurality of groups of capsule 2 in a single branch pipe 12 alternately changes; specifically, only one group of capsule 2 is in the state of filling medium during the whole alternating change process, and the remaining capsules remain in the state of not filling medium; avoid the narrow position of the capsule 2, and thrombosis due to long-time vortex flow of blood.

[0061] There are two ways about the control of the medium output device 3 to the capsule 2.

[0062] Mode one:

[0063] As shown in Figure 2 , the medium output device 3 is provided with two, and each medium output device 3 corresponds to the capsule 2 in a branch pipe 12, and the liquid output end of the present medium output device 3 is connected with the plurality of capsules 2 in the corresponding branch pipe 12 through the hose 4; each hose 4 is provided with a first electromagnetic valve 7, and the capsule 2 is connected with the medium output device 3 through the backflow pipe 8, and the backflow pipe 8 is also provided with a second electromagnetic valve 9.

[0064] The control module 6 controls the first electromagnetic valve 7 and the second electromagnetic valve 9 corresponding to each capsule 2, and then controls the amount of sterile water filled into a single capsule 2.

[0065] Specifically, when it is needed to fill medium in a certain capsule, the first electromagnetic valve 7 on the hose 4 is opened, the second electromagnetic valve 9 on the backflow pipe 8 is closed, the medium output device 3 fills sterile water into the capsule 2, so that the volume of the capsule expands, and when the volume of the capsule expands to match the flow rate of the blood in the two branch pipes, the first electromagnetic valve is closed.

[0066] ​If the flow rate of blood in the two branch pipes changes during the process, the corresponding first electromagnetic valve 7 is opened, so that the medium output device 3 continues to fill the capsule 2 with sterile water; or the second electromagnetic valve 9 is opened, and part of the sterile water in the capsule is discharged from the capsule by the contraction force of the capsule itself and flows back to the medium output device 3; until the flow rates of blood in the two branch pipes match.

[0067] When a period of time elapses, the capsule needs to be restored to the normal state (the state of not being filled with medium), the first electromagnetic valve 7 remains closed, and the second electromagnetic valve 9 is opened, so that the sterile water in the capsule 2 is discharged from the capsule 2 by the contraction force of the capsule 2 itself and flows back to the medium output device 3.

[0068] Method two:

[0069] A kind of as Figure 3 It is shown that: the medium output device 3 is provided with multiple, the number is consistent with the capsule;The liquid output end of each medium output device 3 is connected with a single capsule 2 through a hose 4 respectively;The control module 6 controls the medium output device 3, and then controls the amount of sterile water filled into a single capsule 2.

[0070] The medium output device 3 fills the sterile water in the medium output device 3 into the capsule 2 under the action of pressure, and after the medium output device 3 relaxes (pressure is released), the sterile water in the capsule 2 flows back to the medium output device 3 under the action of the contraction force of the capsule 2 itself.

[0071] The medium output device 3 can be selected as a syringe, and medical staff controls manually according to the flow rate of blood in the two branch pipes 12 displayed on the control module 6.

[0072] The application also provides an embodiment of a flow ratio automatic adjusting method for VAV-ECMO arterial-venous reflux, which is based on a flow ratio automatic adjusting system for VAV-ECMO arterial-venous reflux, and the specific method is as follows,

[0073] In step 100, the sensing module 5 collects the flow rate signals of blood in the two branch pipes 12 and transmits the flow rate signals to the control module 6.

[0074] In step 200, the control module 6 receives and compares the flow rate signals in the two branch pipes 12, controls the medium output device 3 to output medium according to the flow rate difference between the two, changes the volume of any one of the capsules 2 in the branch pipe 12 with a relatively faster flow rate of blood, and then changes the area of the flow cross section at the position of the capsule 2 in the branch pipe 12, so that the flow rates of blood in the two branch pipes 12 match.

[0075] Further, in the VAV-ECMO mode, the control module 6 adjusts the medium output device 3 in real time according to the blood flow signal collected by the sensing module 5 in real time, so as to ensure that the blood flow rates in the two branch pipes 12 are matched, and dynamic adjustment is realized.

[0076] Further, in step 200, the medium output device 3 fills the plurality of capsules 2 in the single branch pipe 12 with the medium in sequence; and during the whole process, only one group of capsules 2 is filled with the medium, and the remaining capsules are not filled with the medium.

[0077] Next, an embodiment of the process in which the medium output device 3 fills the plurality of capsules 2 in the single branch pipe 12 with the medium in sequence is provided as follows.

[0078] Further, in order to realize the sequential adjustment of the plurality of groups of capsules 2 in the single branch pipe 12, the application provides an embodiment as follows.

[0079] The first capsule, the second capsule and the third capsule are respectively arranged in the two branch pipes 12;

[0080] In step 200, the medium output device 3 first fills the first capsule in the branch pipe 12 with the medium, and the second capsule and the third capsule are not filled with the medium; and the process is repeated until the blood flow rates in the two branch pipes are matched.

[0081] After a certain interval of time, the first capsule is uniformly restored to the state of not being filled with the medium and remains in the state of not being filled with the medium; at the same time, the medium output device 3 fills the second capsule with the medium, and the third capsule continues to remain in the state of not being filled with the medium; and the process is repeated until the blood flow rates in the two branch pipes are matched.

[0082] After a certain interval of time, the first capsule continues to remain in the state of not being filled with the medium; the second capsule is uniformly restored to the state of not being filled with the medium and remains in the state of not being filled with the medium; the medium output device 3 fills the third capsule with the medium; and the process is repeated until the blood flow rates in the two branch pipes are matched.

[0083] The interval of time can be determined according to the actual situation of the patient, and specifically, the interval of time is determined to avoid thrombosis at the capsule 2 in the branch pipe 12.

[0084] The embodiment avoids thrombosis at the position of the single capsule 2 due to long-term pressure, and the change process of the capsule 2 is a uniform change process, so as to avoid fluctuations in the blood flow rate in the branch pipe 12 due to sudden changes in the volume of the capsule 2.

[0085] The above examples are only exemplary embodiments of the present application, and are not intended to limit the present application, and the protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements are also considered to fall within the protection scope of the present application.

Claims

1. An automatic flow ratio adjustment system for arteriovenous return in VAV-ECMO, characterized in that, include: The Y-shaped connecting tube (1) includes a main branch tube (11) and two branch tubes (12) formed by bifurcating from one end of the main branch tube (11); wherein the end of the main branch tube (11) is used to connect to a venous drainage tube, and the ends of the two branch tubes (12) are used to connect to a venous return tube and an arterial return tube, respectively. At least one of the capsules (2) is provided on the inner wall of each of the two branch pipes (12) of the Y-shaped connecting pipe (1); the capsule (2) is made of deformable material; The medium output device (3) is located outside the Y-shaped connecting pipe (1), and the medium output device (3) is connected to the interior of the multiple capsules (2) through the hose (4); The medium output device (3) is used to fill the inside of the capsule (2) with medium, so that the capsule (2) deforms and thereby changes the area of ​​the flow section at the location of the capsule (2) in the branch pipe (12); The sensing module (5) is provided in two sets, which are respectively set at the ends of the two branch pipes (12); The sensing module (5) is used to collect the speed of blood flow in the two branch tubes (12); The control module (6) is connected to the sensing module (5) to receive and analyze the blood flow velocity in the two branch tubes (12); based on the blood flow velocity difference in the two branch tubes (12), the control module (3) controls the amount of medium filled into the sac (2) inside the corresponding branch tube (12) by the medium output device (3) so that the blood flow velocity in the two branch tubes (12) is matched. Multiple sets of bladders (2) are provided in a single branch tube (12), and the multiple sets of bladders (2) are alternately arranged at two symmetrical positions along the inner wall of the branch tube (12); Furthermore, the volume of multiple sets of cysts (2) within a single branch tube (12) changes alternately; during the alternation process, only one set of cysts (2) is in a state of being filled with medium, while the remaining cysts remain in a state of not being filled with medium.

2. The automatic flow ratio adjustment system for arteriovenous return in VAV-ECMO according to claim 1, characterized in that, The capsule (2) is made of an elastic material, and its volume changes accordingly depending on the amount of medium being filled.

3. The automatic flow ratio adjustment system for arteriovenous return in VAV-ECMO according to claim 1 or 2, characterized in that, The capsule (2) is formed by fixing the edge of an elastic membrane to the inner wall of the branch tube (12).

4. The automatic flow ratio adjustment system for arteriovenous return in VAV-ECMO according to claim 3, characterized in that, The capsule (2) is not filled with a medium when the elastic film is attached to the inner wall of the branch tube (12).

5. The automatic flow ratio adjustment system for arteriovenous return in VAV-ECMO according to claim 4, characterized in that, The capsule is composed of 3 groups.

6. A method for automatically adjusting the flow ratio for arteriovenous return in VAV-ECMO, characterized in that, The automatic flow ratio adjustment system for arteriovenous return in VAV-ECMO according to any one of claims 1-5 is described in the following specific method. Step 100: The sensing module (5) collects the blood flow rate signals in the two branch tubes respectively and transmits the flow rate signals to the control module (6). Step 200: The control module (6) receives and compares the flow velocity signals in the two branch tubes (12). Based on the flow velocity difference between the two, the control module (3) outputs the medium to change the volume of any one of the sacs (2) in the branch tube (12) with a relatively fast blood flow velocity, thereby changing the area of ​​the flow cross section at the location of the sac (2) in the branch tube (12) so that the blood flow velocities in the two branch tubes (12) are matched.

7. The automatic flow ratio adjustment method for arteriovenous return in VAV-ECMO according to claim 6, characterized in that, In step 200, the control module (6) adjusts the amount of medium output by the medium output device (3) in real time according to the blood flow rate signal collected in real time by the sensing module (5) to ensure that the blood flow rates in the two branch tubes are matched.

8. The automatic flow ratio adjustment method for arteriovenous return in VAV-ECMO according to claim 7, characterized in that, In step 200, the medium output device (3) sequentially fills the multiple capsules (2) in a single branch tube (12) with medium; Throughout the process, only one set of capsules (2) is filled with the medium, while the remaining capsules are not filled with the medium.

9. The automatic flow ratio adjustment method for arteriovenous return in VAV-ECMO according to claim 8, characterized in that, Each of the two branch tubes (12) is provided with a first bladder, a second bladder, and a third bladder; In step 200, the medium output device (3) first fills the first sac inside the branch tube (12) with a faster blood flow rate with medium, while the second sac and the third sac remain unfilled with medium until the blood flow rates in the two branch tubes (12) are matched. After a fixed time interval, the first capsule returns to the state of not being filled with medium at a constant speed and remains in the state of not being filled with medium; at the same time, the medium output device (3) fills the second capsule with medium, and the third capsule continues to remain in the state of not being filled with medium; until the blood flow rates in the two branch tubes (12) are matched; After a fixed time interval, the first capsule remains unfilled with medium; the second capsule returns to the unfilled state at a constant speed and remains unfilled with medium; the medium output device (3) fills the third capsule with medium; until the blood flow rates in the two branch tubes (12) are matched; Repeat the above steps after a fixed time interval.

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