Artificial membrane lung unit, assembly and manufacturing method thereof

Abstract

The present invention provides an artificial membrane lung unit, assembly, and manufacturing method thereof, wherein the artificial membrane lung unit comprises a glass capillary and a hollow fiber membrane tube; the hollow fiber membrane tube is made of silicone rubber and is nested in the glass capillary; the inner wall of the glass capillary has raised portions and recessed portions, the raised portions and recessed portions extending axially and convex or concave radially; the raised portions and recessed portions are uniformly arranged alternately along the circumference of the inner wall of the glass capillary, so that the inner surface of the glass capillary presents an uneven and rough shape; the inner surface of the glass capillary is coated with heparin. The present invention adopts a compact design with a simple structure and a small size. By controlling the air pressure within the membrane, the thickness of the membrane can be uniformly reduced, while the size of the blood flow channel can be reduced to a size close to that of human capillaries, thereby greatly reducing the gas mass transfer resistance on the membrane side and the blood side, and significantly improving the gas exchange efficiency.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an artificial membrane lung unit, components and a manufacturing method thereof. Background Art

[0002] Extracorporeal membrane oxygenator (ECMO) is a new technology for saving the lives of critically ill patients. It is essentially a modified artificial heart-lung machine. The core parts are the membrane lung component and the blood pump component, which act as artificial lungs and artificial hearts respectively. It can be used to support various serious respiratory diseases and rescue heart failure such as acute myocardial infarction.

[0003] When the extracorporeal membrane oxygenation (ECMO) device is in operation, blood is drawn from the veins and passes through the membrane oxygenator, absorbing oxygen and releasing carbon dioxide. The blood, after undergoing gas exchange, is then pumped back into the veins or arteries by the blood pump assembly. The former is primarily used for extracorporeal respiratory support, while the latter, because the blood pump assembly replaces the heart's pumping function, can be used for both extracorporeal respiratory support and cardiac support. When a patient's lung function is severely impaired and conventional treatment is ineffective, the ECMO device can take over the gas exchange, allowing the lungs to rest and buying valuable time for the patient's recovery.

[0004] Since the main function of the membrane lung component is to achieve gas exchange in the blood, how to improve the gas exchange efficiency of the membrane lung component is an issue that requires continuous research and improvement. Summary of the Invention

[0005] The object of the present invention is to provide an artificial membrane lung unit, an assembly and a manufacturing method thereof, which have the advantages of simple structure, compact size and high gas exchange efficiency.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] An artificial membrane lung unit comprises a glass capillary tube and a hollow fiber membrane tube; the hollow fiber membrane tube is made of silicone rubber and is nested in the glass capillary tube;

[0008] The inner wall of the glass capillary tube has raised portions and recessed portions, which extend axially and are convex or concave in the radial direction. The raised portions and recessed portions are evenly and alternately arranged circumferentially on the inner wall of the glass capillary tube, so that the inner surface of the glass capillary tube presents an uneven and rough shape. The inner surface of the glass capillary tube is coated with heparin.

[0009] Furthermore, the outer diameter of the glass capillary is 2 mm to 3 mm, and the inner diameter is 1.5 mm to 2 mm.

[0010] Furthermore, the outer diameter of the hollow fiber membrane tube in the initial state is 0.3 mm-1 mm, and the inner diameter is 0.2 mm-0.8 mm.

[0011] Furthermore, the height difference between the raised portion and the recessed portion is 5 μm-20 μm.

[0012] An artificial membrane lung assembly comprises the artificial membrane lung unit described above, further comprising an outer shell, a first end cap and a second end cap, wherein the outer shell is in a hollow cylindrical shape, and the first end cap and the second end cap are fixedly connected at both ends of the outer shell respectively;

[0013] The first end cap is provided with a blood inlet and an oxygen inlet, and the second end cap is provided with a blood outlet and an oxygen outlet;

[0014] Multiple artificial membrane lung units are tightly arranged, encapsulated and fixed in the shell; in each artificial membrane lung unit, one end of the hollow fiber membrane tube is connected to the oxygen inlet, the other end of the hollow fiber membrane tube is connected to the oxygen outlet, one end of the annular gap between the hollow fiber membrane tube and the glass capillary is connected to the blood inlet, and the other end of the annular gap is connected to the blood outlet.

[0015] Furthermore, an air pressure regulating device is provided at the oxygen inlet and / or the oxygen outlet.

[0016] Furthermore, the shell, the first end cap and the second end cap are made of medical-grade PVC material.

[0017] The method for manufacturing the above-mentioned artificial membrane lung assembly comprises the following steps:

[0018] S1, etching a recessed portion on the inner wall of the glass capillary to form an uneven rough structure on the inner surface of the glass capillary;

[0019] S2, grafting heparin on the inner surface of the glass capillary;

[0020] S3, coating one end of the glass capillary with epoxy glue, and then stacking them in the housing to form a capillary array;

[0021] S4. After the epoxy resin glue is dry, use a threading machine to insert the hollow fiber membrane tube from the other end of the glass capillary;

[0022] S5. After all the glass capillaries are threaded, apply epoxy glue to the other end of the glass capillaries and wait for it to dry.

[0023] S6. After the glass capillary tube is encapsulated and fixed in the housing, the end portions of both ends of the glass capillary tube are cut off to expose the inner cavity of the hollow fiber membrane tube and the glass capillary tube;

[0024] S7. Fix the first cover and the second cover to both ends of the housing, connect the oxygen inlet and the oxygen outlet to the inner cavity of the hollow fiber membrane tube, and connect the blood inlet and the blood outlet to the annular gap between the hollow fiber membrane tube and the glass capillary tube.

[0025] Furthermore, in S1, a nozzle is used to spray hydrofluoric acid onto the inner wall of the glass capillary for etching; the concentration of the hydrofluoric acid is 10%-30%.

[0026] Furthermore, in S2, before grafting heparin onto the inner surface of the glass capillary, the method further includes: soaking the etched glass capillary in polyimide for a period of time, and then performing plasma treatment on the glass capillary after drying.

[0027] The present invention provides an artificial membrane lung unit, assembly, and manufacturing method thereof. Leveraging the expandable nature of silicone rubber membranes, the present invention reduces the difficulty of manufacturing the artificial membrane lung assembly, improves the yield rate, and significantly enhances production efficiency. The artificial membrane lung assembly provided by the present invention features a compact design, simple structure, and compact size. By controlling the air pressure within the membrane to cause the membrane body to expand, the membrane thickness can be adjusted to less than 10 microns. This simultaneously reduces the size of the blood flow path to a size close to that of human capillaries, thereby significantly reducing the gas mass transfer resistance on both the membrane and blood sides and significantly improving gas exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a cross-sectional structural diagram of an artificial membrane lung unit provided in Example 1 of the present invention.

[0029] Figure 2 This is a working principle diagram of an artificial membrane lung unit provided in Example 1 of the present invention.

[0030] Figure 3 This is a schematic structural diagram of an artificial membrane lung assembly provided in Example 2 of the present invention.

[0031] Figure 4 yes Figure 3 AA cross-section diagram. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] like Figure 1 As shown, an artificial membrane lung unit provided by an embodiment of the present invention includes a glass capillary tube 2 and a hollow fiber membrane tube 1. The hollow fiber membrane tube 1 is made of silicone rubber, and the hollow fiber membrane tube 1 is nested in the glass capillary tube 2.

[0035] Specifically, the inner wall of the glass capillary tube 2 has raised portions and recessed portions, which extend in the axial direction and are raised or recessed in the radial direction. The raised portions and recessed portions are evenly and alternately arranged in the circumferential direction on the inner wall of the glass capillary tube 2, so that the inner surface of the glass capillary tube 2 has an uneven and rough shape. The inner surface of the glass capillary tube 2 is coated with heparin.

[0036] In this embodiment, the recessed portion is a groove etched on the inner wall of the glass capillary 2, and the unetched portion forms a raised portion. The height difference between the raised portion and the recessed portion is 5 μm-20 μm. Preferably, the height difference is 10 μm.

[0037] Furthermore, the outer diameter of the glass capillary is 2 mm to 3 mm, and the inner diameter is 1.5 mm to 2 mm. The outer diameter of the hollow fiber membrane tube in the initial state (unexpanded state) is 0.3 mm to 1 mm, and the inner diameter is 0.2 mm to 0.8 mm. Preferably, the inner and outer diameters of the capillary are 1.5 mm and 2.5 mm, respectively, and the inner and outer diameters of the hollow fiber membrane tube are 0.5 mm and 0.8 mm, respectively.

[0038] Combine Figure 2 As shown, the artificial membrane lung unit provided in this embodiment imitates the structural design of natural alveoli. During operation, blood flows through the annular gap between the glass capillary 2 and the hollow fiber membrane tube 1, and oxygen flows through the hollow fiber membrane tube 1.

[0039] Because the hollow fiber membrane tube 1 is made of silicone rubber, the membrane structure is dense and has a certain degree of elasticity. By increasing the air pressure within the hollow fiber membrane tube 1, the hollow fiber membrane tube 1 can be expanded, thereby reducing the thickness of the hollow fiber membrane tube 1. In this embodiment, the air pressure within the hollow fiber membrane tube 1 ranges from 1.01 to 1.08 atmospheres, which can reduce the thickness of the hollow fiber membrane tube 1 to a maximum of 35% to 50% of its normal state.

[0040] During the expansion of the hollow fiber membrane tube 1, the thickness of the annular gap between the glass capillary tube 2 and the hollow fiber membrane tube 1 decreases, increasing the contact area between blood and the outer wall of the hollow fiber membrane tube 1. Gas exchange occurs across the membrane through dissolution and diffusion. The thickness of the annular gap depends primarily on the protrusions and depressions on the inner wall of the glass capillary tube, as well as the air pressure within the hollow fiber membrane tube 1. In this embodiment, the thickness of the annular gap can be adjusted between 5 μm and 20 μm.

[0041] Through the above adjustment process, the gas mass transfer resistance on the membrane side and the blood side can be greatly reduced, and the gas exchange efficiency can be significantly improved.

[0042] Example 2

[0043] like Figure 3 and Figure 4 As shown, this embodiment provides an artificial membrane lung assembly, comprising the artificial membrane lung unit described in Example 1, and further comprising a housing 3, a first end cap, and a second end cap. The housing 3 is hollow and cylindrical, with the first and second end caps fixedly connected at both ends. The first end cap is provided with a blood inlet 51 and an oxygen inlet 41, and the second end cap is provided with a blood outlet 52 and an oxygen outlet 42.

[0044] The shell 3, the first end cap and the second end cap are all made of medical grade PVC material. The shell 3 can be a cylinder or a rectangular cylinder. In this embodiment, a rectangular cylinder with a square cross section is used.

[0045] A plurality of artificial membrane lung units are tightly arranged and encapsulated and fixed in the shell 3; in each artificial membrane lung unit, one end of the hollow fiber membrane tube 1 is connected to the oxygen inlet 41, the other end of the hollow fiber membrane tube 1 is connected to the oxygen outlet 42, one end of the annular gap between the hollow fiber membrane tube 1 and the glass capillary tube 2 is connected to the blood inlet 51, and the other end of the annular gap is connected to the blood outlet 52.

[0046] Furthermore, an air pressure regulating device is provided at the oxygen inlet 51 and / or the oxygen outlet 52 for regulating the air pressure in the hollow fiber membrane tube 1 .

[0047] In this embodiment, the length of the artificial membrane lung unit encapsulated in the housing 3 is preferably 20 cm to 30 cm.

[0048] Example 3

[0049] This embodiment provides a method for manufacturing an artificial membrane lung assembly to manufacture the artificial membrane lung assembly described in Example 2. The manufacturing method comprises the following steps:

[0050] S1. Etching a concave portion on the inner wall of the glass capillary to form a rough, uneven structure on the inner surface of the glass capillary. Specifically, using a nozzle, spraying hydrofluoric acid with a concentration of 10%-30% on the inner wall of the glass capillary to etch the concave portion.

[0051] S2. Soaking the etched glass capillary in polyimide for a period of time, and then performing plasma treatment on the glass capillary after drying; and then grafting heparin on the inner surface of the glass capillary.

[0052] S3. Apply epoxy glue to one end of the glass capillary and then stack them in the housing to form a capillary array.

[0053] S4. After the epoxy resin glue dries, use a threading machine to insert the hollow fiber membrane tube from the other end of the glass capillary.

[0054] S5. After all the glass capillaries are threaded, apply epoxy glue on the other end of the glass capillaries and wait for it to dry.

[0055] S6. After the glass capillary is encapsulated and fixed in the housing, the end portions of both ends of the glass capillary are cut off to expose the inner cavity of the hollow fiber membrane tube and the glass capillary.

[0056] S7. Fix the first cover and the second cover to both ends of the housing, connect the oxygen inlet and the oxygen outlet to the inner cavity of the hollow fiber membrane tube, and connect the blood inlet and the blood outlet to the annular gap between the hollow fiber membrane tube and the glass capillary tube.

[0057] Since the hollow fiber membrane tube is made of silicone rubber material, under normal conditions, the diameter of the hollow fiber membrane tube is relatively small; during production, the annular gap between the outer wall of the hollow fiber membrane tube and the inner wall of the glass capillary is relatively large, and the hollow fiber membrane tube can be easily passed through the glass capillary using a threading machine, which greatly reduces the difficulty of producing artificial membrane lung components, improves the yield rate, and significantly improves production efficiency.

[0058] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An artificial membrane lung assembly, characterized in that: It includes an artificial membrane lung unit, a shell, a first end cover and a second end cover; The shell is in the shape of a hollow cylinder, with a first end cap and a second end cap fixedly connected at both ends of the shell; the first end cap is provided with a blood inlet and an oxygen inlet, and the second end cap is provided with a blood outlet and an oxygen outlet; a plurality of artificial membrane lung units are closely arranged and encapsulated and fixed in the shell; The artificial membrane lung unit includes a glass capillary tube and a hollow fiber membrane tube; the hollow fiber membrane tube is made of silicone rubber, and the hollow fiber membrane tube is nested in the glass capillary tube; The inner wall of the glass capillary tube has raised portions and recessed portions, the raised portions and recessed portions extending in the axial direction and being raised or recessed in the radial direction; the raised portions and recessed portions are alternately and evenly arranged in the circumferential direction on the inner wall of the glass capillary tube, so that the inner surface of the glass capillary tube presents an uneven and rough shape; the inner surface of the glass capillary tube is coated with heparin; In each artificial membrane lung unit, one end of the hollow fiber membrane tube is connected to the oxygen inlet, the other end of the hollow fiber membrane tube is connected to the oxygen outlet, one end of the annular gap between the hollow fiber membrane tube and the glass capillary tube is connected to the blood inlet, and the other end of the annular gap is connected to the blood outlet; By increasing the air pressure in the hollow fiber membrane tube, the hollow fiber membrane tube expands and its thickness decreases, thereby increasing the contact area between blood and the outer wall of the hollow fiber membrane tube, thereby improving gas exchange efficiency.

2. The artificial membrane lung assembly according to claim 1, characterized in that The outer diameter of the glass capillary is 2 mm to 3 mm, and the inner diameter is 1.5 mm to 2 mm.

3. The artificial membrane lung assembly according to claim 1, characterized in that The outer diameter of the hollow fiber membrane tube in the initial state is 0.3 mm-1 mm, and the inner diameter is 0.2 mm-0.8 mm.

4. The artificial membrane lung assembly according to claim 1, characterized in that The height difference between the protrusion and the depression is 5 μm to 20 μm.

5. The artificial membrane lung assembly according to claim 1, characterized in that An air pressure regulating device is provided at the oxygen inlet and / or the oxygen outlet.

6. The artificial membrane lung assembly according to claim 1, characterized in that The housing, the first end cap and the second end cap are made of medical-grade PVC material.

7. A method for manufacturing the artificial membrane lung assembly according to claim 1, characterized in that: The following steps are involved: S1, etching a recessed portion on the inner wall of the glass capillary to form an uneven rough structure on the inner surface of the glass capillary; S2, grafting heparin on the inner surface of the glass capillary; S3, coating one end of the glass capillary with epoxy glue, and then stacking them in the housing to form a capillary array; S4. After the epoxy resin glue is dry, use a threading machine to insert the hollow fiber membrane tube from the other end of the glass capillary; S5. After all the glass capillaries are threaded, apply epoxy glue to the other end of the glass capillaries and wait for it to dry. S6. After the glass capillary tube is encapsulated and fixed in the housing, the end portions of both ends of the glass capillary tube are cut off to expose the inner cavity of the hollow fiber membrane tube and the glass capillary tube; S7. Fix the first cover and the second cover to both ends of the housing, connect the oxygen inlet and the oxygen outlet to the inner cavity of the hollow fiber membrane tube, and connect the blood inlet and the blood outlet to the annular gap between the hollow fiber membrane tube and the glass capillary tube.

8. The method for manufacturing an artificial membrane lung assembly according to claim 7, characterized in that: In S1, a nozzle is used to spray hydrofluoric acid onto the inner wall of the glass capillary for etching; the concentration of the hydrofluoric acid is 10%-30%.

9. The method for manufacturing an artificial membrane lung assembly according to claim 7, characterized in that: In S2, before grafting heparin onto the inner surface of the glass capillary, the method further includes: soaking the etched glass capillary in polyimide for a period of time, and performing plasma treatment on the glass capillary after drying.

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