Medical filter and preparation method thereof

Abstract

The invention relates to the technical field of filtering devices, in particular to a medical filter and a preparation method thereof.The filter comprises a flow dividing assembly, a liquid inlet filter membrane and a liquid outlet filter membrane; wherein the liquid inlet filter membrane and the liquid outlet filter membrane are arranged on the two sides of the flow dividing assembly respectively, and a first liquid passing cavity supported by the flow dividing assembly is formed; the liquid inlet filter membrane and the liquid outlet filter membrane are arranged on the two sides of the flow dividing assembly respectively, a two-stage filter channel is formed, and liquid medicine is primarily filtered through the liquid inlet filter membrane, then evenly dispersed through the cavity supported by the flow dividing assembly and finally secondarily filtered through the liquid outlet filter membrane; a double-membrane structure is used for filtering twice, so that the impurity interception capability can be remarkably enhanced, and meanwhile, the stability of the filter during intermittent working can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of filter devices, and in particular to a medical filter and a preparation method thereof. Background Art

[0002] Filtration equipment is widely used in the medical field, covering air purification, water treatment, pharmaceutical production and other aspects. For intravenous infusion, medical filters are used to ensure the safe infusion of liquid medicine and prevent particles or bubbles from entering the patient's blood system.

[0003] Chinese Patent Authorization Publication No. CN113117397B discloses a medical filter for infusion, comprising a main body and a side cover, wherein an inner cavity is formed between the main body and the side cover, the inner cavity comprising a first chamber and a second chamber, the first chamber being defined by the side cover, the main body, and a filter membrane, and the second chamber being defined by the main body and the filter membrane. A first channel for fluid inflow and a second channel for fluid outflow are respectively provided at each end of the main body. The invention is characterized in that: a filter membrane mounting bracket is provided within the main body, a diverter cavity is provided between the filter membrane mounting bracket and the outlet of the first channel, a diverter portion is provided within the diverter cavity, the diverter portion is aligned with the outlet of the first channel, the diverter portion is fixed to the filter membrane mounting bracket, and the diverter portion protrudes relative to the filter membrane mounting bracket toward the side cover, the diverter cavity is connected to the first chamber, and the second channel is connected to the second chamber. The invention aims to provide a medical filter for infusion that can achieve high-efficiency and precision filtration.

[0004] Chinese Patent Authorization Announcement No. CN214319316U discloses a medical suction filter with an offset liquid outlet tube, relating to the field of medical devices, and comprising a medical suction filter having a housing and a liquid outlet tube. The liquid outlet tube of the medical suction filter is disposed on one side of the bottom of the housing, the inner cavity of the liquid outlet tube communicates with the inner cavity of the housing, and the inner cavity axis of the liquid outlet tube forms an angle with the inner cavity axis of the housing, and the end of the liquid outlet tube away from the housing extends toward a side away from the inner cavity axis of the housing. The liquid outlet tube is offset so that the liquid outlet tube is closer to the side wall of the housing, reducing the obstruction between the side wall of the housing and the inner wall of the liquid outlet tube. The liquid outlet tube extends in a direction away from the inner cavity axis, allowing blood to quickly discharge from the filter along the liquid outlet tube under the action of gravity and not easily coagulate.

[0005] Chinese Patent Authorization Publication No. CN213790973U discloses a filter comprising a liquid inlet, a liquid outlet, a top cover, a bottom cover, and a filter plate sealed between the top and bottom covers. The filter plate comprises a membrane support plate and first and second filter membranes sealed to the first and second surfaces of the membrane support plate, respectively. The first and second surfaces of the membrane support plate are formed with first and second through-holes, respectively, and a confluence channel formed between the first and second surfaces and communicating with the first and second through-holes and the liquid outlet. The first and second filter membranes cover the first and second through-holes, respectively. A raw material fluid flows into the liquid inlet, is filtered by the first and second filter membranes, and the clean filtrate passes through the first and second through-holes, converges into the confluence channel, and finally flows to the liquid outlet and is discharged. In this filter, the membrane support plate has a simple structure, is easy to manufacture, and assemble, and can provide a larger filtration area and a simple fluid flow path.

[0006] However, the filter membranes of the above-mentioned medical filters are all single-layer structures, and the filtering effect is poor. At the same time, when working for a long time or intermittently, the filter will have a poor liquid flow effect, affecting the stability of the filter during operation. Summary of the Invention

[0007] To this end, the present invention provides a medical filter and a preparation method thereof, so as to overcome the problem that the filter membranes of medical filters in the prior art are all single-layer structures, resulting in poor filtering effect. At the same time, when working for a long time or intermittently, the liquid flow effect of the filter will be poor, affecting the stability of the filter during operation.

[0008] To achieve the above objectives, the present invention provides, in one aspect, a medical filter, wherein the filter chamber is configured as a circular pancake-shaped structure including an input chamber and an output chamber, the filter chamber being arranged longitudinally, a liquid inlet being provided above the input chamber, and a liquid outlet being provided below the output chamber; and a flow diversion assembly and a flow plate being provided between the input chamber and the output chamber; Input and output caps for sealing the filter; The two sides of the diversion component are wrapped with an inlet filter membrane and an outlet filter membrane, forming a first liquid-passing cavity supported by the diversion component for receiving the liquid filtered by the inlet filter membrane; The outlet filter membrane and the flow plate form a second liquid passage cavity for receiving the liquid filtered by the outlet filter membrane, and the second liquid passage cavity is partitioned by the diversion assembly and the flow plate, and the second liquid passage cavity is divided into an upper part and a lower part; For the effluent filter membrane, In response to the filtration being performed, the outlet filter membrane filters the liquid in the first liquid passage cavity at the upper portion of the second liquid passage cavity; In response to filtration stopping, the outlet filter membrane blocks the gas that is not exhausted during the filtration stopping at the lower portion of the second liquid-passing cavity.

[0009] Furthermore, the diversion assembly includes several groups of support structures arranged with different lengths; Wherein, the long axis of each supporting structure is perpendicular to the corresponding plane of the flow plate; For each support structure that has the same vertical distance from the liquid inlet, the lengths thereof are the same; The inlet filter membrane and the outlet filter membrane are supported by the support structure and form the first liquid passage cavity.

[0010] Furthermore, the flow plate is arranged on the output bin and has a flow hole, and the flow hole is arranged on a side close to the liquid inlet; The flow hole is located at the upper part of the second liquid passage cavity, and the flow hole itself is not separated by the partition.

[0011] Furthermore, the input chamber is used to receive the filtered liquid, and the inlet filter membrane forms an inclined surface with the diversion component to increase the filtering area; Wherein, the liquid inlet filter membrane filters the liquid once in the filtering state; During the primary filtration, the input chamber is gradually filled with liquid and flows into the first liquid passage cavity.

[0012] Furthermore, the inclined surface is supported by the supporting structure and formed by the height difference of each supporting structure. The central area of ​​the liquid inlet filter membrane is higher than the edge area, forming a ridge-like structure protruding toward the input cover.

[0013] Furthermore, the flow holes are concentrated in the upper center area of ​​the flow plate, and all the flow holes are located above the partition; The output cover and the flow plate form an output chamber, and the output chamber is connected with the second liquid passage cavity and the liquid outlet.

[0014] Furthermore, the effluent filter membrane filters the liquid filtered by the effluent filter membrane to perform secondary filtration; In the filtering state, the upper portion of the second liquid passage cavity receives the filtered liquid, and the liquid flows into the output bin through the flow hole.

[0015] Furthermore, the inlet filter membrane and the outlet filter membrane are configured as nuclear pore membranes.

[0016] In another aspect, a method for preparing a medical filter comprises: Prepare the housing, flow plate and sealing cover; and forming a filtration group consisting of an outlet filter membrane, a diversion component, and an inlet filter membrane; Assemble the filter; When forming the filter group, it includes: Step S1, cutting the effluent filter membrane and the inlet filter membrane, and pressing the edges of the effluent filter membrane and the inlet filter membrane to form a filter bag; Step S2, opening the filter bag and placing the diversion assembly into the filter bag; and Arrange the filter bag so that the opening of the filter bag is at the preset opening; Step S3, pressing the filter group toward the flow plate so that the edge of the filter bag is pressed tightly against the housing, and the opening is located between the flow plate and the diversion assembly; Wherein, the preset opening is arranged parallel to the supporting structure of the diversion component, and the opening size is not greater than 1 / 3 of the circumference of the diversion component.

[0017] Furthermore, in step S1, when cutting the effluent filter membrane, the effluent filter membrane is cut into an elliptical shape, the minor axis of which is not less than the diameter of the flow plate, the major axis of which is not less than the diameter of the housing, and not greater than 1.5 times the horizontal projection diameter of the diversion component; When cutting the inlet filter membrane, the inlet filter membrane is cut into a circular shape, the diameter of which is not less than the diameter of the shell and not larger than the long axis of the outlet filter membrane; When forming the filter bag, the corresponding surface of the inlet filter membrane is pressed against the outlet filter membrane; The preset opening is opened at a position corresponding to the long axis of the outlet filter membrane; When assembling the filter, the filter group is formed into a disc-shaped filter group by being supported by the diversion component, and the filter group is pressed toward the flow plate, and the edge of the inlet filter membrane is pressed into the outer shell of the filter to complete the assembly.

[0018] Furthermore, in step S2, in order to match the support structures of different lengths provided on the diversion assembly, the position where the long axis of the effluent filter membrane is located is opened, so that the diversion assembly as a whole can be placed in the corresponding position. At the same time, Because the size of the filter bag is slightly larger than the diversion assembly, the supporting structures of the diversion assembly can support several separated areas in the filter bag to form a first liquid-passing cavity inside the filter bag, and press on the flow plate to form the upper and lower parts of the second liquid-passing cavity.

[0019] Furthermore, when assembling the filter, the following steps are also included: Clean air is poured into the filter group through its opening; When the filter group is inflated, press the inflated filter group into the corresponding position of the housing.

[0020] Compared with existing technologies, the present invention offers the advantage of creating a two-stage filtration channel by placing the inlet and outlet membranes on either side of the diversion assembly. The medicinal solution is initially filtered by the inlet membrane, then evenly dispersed through the cavity supported by the diversion assembly, and finally finely filtered by the outlet membrane. This dual-membrane structure significantly enhances impurity retention and reduces the risk of clogging.

[0021] Furthermore, the support structure of the diversion assembly is designed to create a height difference, giving the inlet filter membrane a dome-like slope, with a high center and low edges. This structure significantly increases the contact area between the liquid and the filter membrane, while also guiding the fluid to diffuse naturally, reducing turbulence and dead spots, and ensuring filtration uniformity.

[0022] Furthermore, the support structure precisely supports the dual-layer filter membranes to form a stable first liquid flow cavity, while the second liquid flow cavity, formed by the flow plate and the outlet filter membrane, is divided into upper and lower parts. This design maintains the cavity shape and, combined with the concentrated distribution of flow holes in the upper center area, achieves directional flow guidance and prevents liquid retention.

[0023] Compared with the prior art, the present invention has the beneficial effects that the filter group adopts an integrated structure to reduce assembly parts, while the indentation fits closely with the support structure to improve the sealing effect and reduce the risk of leakage.

[0024] At the same time, in order to solve the problem of using only a single-layer filter membrane for filtration in the prior art, the present invention provides a filter group with a double-layer filter membrane in a form away from the sealing cover of the filter box. At the same time, in order to avoid the problem of filter membrane adhesion leading to a decrease in filtration effect and filtration efficiency, the present invention provides a corresponding diversion component to avoid the problem of filter membrane adhesion; However, due to the provision of a diversion component, tiny bubbles originating from the medicinal liquid will be filtered by the filter membrane and adsorbed on the inlet filter membrane or the outlet filter membrane, affecting the liquid discharge effect. The present invention provides several inclined filtering surfaces so that these bubbles can be blocked at a position close to the bottom of the filter, which can effectively avoid the problem of poor liquid discharge effect caused by air traps.

[0025] To address the problem in the prior art that, during long-term or intermittent operation, the filter may experience poor liquid flow and affect its stability during operation, the present application provides a second liquid passage cavity at the bottom as a buffer, and utilizes the opening of the filter group to create a movable chamber that communicates with the first liquid passage cavity. During the interruption, some air is stored in the lower part of the second liquid passage cavity. When the filtration is restarted, the second liquid passage cavity intercepts some bubbles to prevent the bubbles from entering the upper part of the first liquid passage cavity, which can effectively improve the filtration efficiency when the filtration is restarted. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the medical filter of the present invention; Figure 2 is a cross-sectional view of a filter according to an embodiment of the present invention; Figure 3 A top view of a flow diversion assembly according to an embodiment of the present invention; Figure 4 Schematic diagram of liquid flow according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the membrane filter workflow according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the membrane termination process according to an embodiment of the present invention; Figure 7 This is a flow chart of the preparation method of the medical filter of the present invention; Figure 8 This is a schematic diagram of an assembly groove according to an embodiment of the present invention; Among them: 1, filter chamber; 11, input chamber; 111, liquid inlet; 12, output chamber; 121, liquid outlet; 13, first liquid passage cavity; 14, second liquid passage cavity; 141, upper part of the second liquid passage cavity; 142, lower part of the second liquid passage cavity; 15, shell groove; 2, flow plate; 21, flow hole; 22, flow plate groove; 3, diversion assembly; 4, filter membrane; 41, liquid inlet filter membrane; 42, liquid outlet filter membrane; 5, input cover; 6, output cover; 61, exhaust hole. DETAILED DESCRIPTION

[0027] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0028] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0030] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] See also Figure 1 As shown, it is a schematic structural diagram of the medical filter of the present invention. In the figure, the filter chamber 1 is provided with a circular cake-shaped structure and is arranged longitudinally, including: The filter chamber 1 is configured as an input chamber 11 and an output chamber 12, wherein the input chamber 11 is provided with a liquid inlet 111 and the output chamber 12 is provided with a liquid outlet 121; A flow diversion assembly 3 is provided between the input bin 11 and the output bin 12; A flow plate 2 is provided with a flow hole 21; An input cover 5 and an output cover 6 for sealing the filter; It is characterized in that the filter membrane 4 is arranged on both sides of the diversion component 3, including: An inlet filter membrane 41 is provided in the input chamber 11 and forms an input chamber with the input cover 5 and the input chamber 11; and, an outlet filter membrane 42 disposed on the other side of the diversion component 3; The inlet filter membrane 41 and the outlet filter membrane 42 are respectively arranged on both sides of the diversion component 3, and form a first liquid passage cavity 13 supported by the diversion component 3, for receiving the liquid filtered by the inlet filter membrane 41; The effluent filter membrane 42 and the flow plate 2 form a second liquid passage cavity 14 for receiving the liquid filtered by the effluent filter membrane 42. The second liquid passage cavity 14 is partitioned by the diverter assembly 3 and the flow plate 2, and is divided into an upper portion and a lower portion. In response to the filtration proceeding, the effluent filter membrane 42 filters the liquid in the first liquid passage cavity 13 at the upper portion of the second liquid passage cavity 14; In response to the filtration being stopped, the effluent filter membrane 42 blocks the gas in the first liquid-passing cavity 13 at the lower portion of the second liquid-passing cavity 14 .

[0032] By placing an inlet filter membrane 41 and an outlet filter membrane 42 on either side of the diversion assembly 3, a two-stage filtration channel is formed. The liquid is initially filtered by the inlet filter membrane 41, then evenly dispersed through the cavity supported by the diversion assembly 3, and finally finely filtered by the outlet filter membrane 42. This dual-membrane structure significantly enhances impurity retention and reduces the risk of clogging.

[0033] Specifically, the diverter assembly 3 includes several groups of support structures arranged with different lengths; Among them, each supporting structure is perpendicular to the corresponding plane of the flow plate 2; For each supporting structure that is at the same distance from the plane corresponding to the liquid inlet, its length is the same; The inlet filter membrane 41 and the outlet filter membrane 42 are supported by the support structure and form a first liquid passage cavity 13 .

[0034] See also Figure 2 As shown, it is a cross-sectional view of the filter according to an embodiment of the present invention. Figure 2 The state shown is a reference, and the supporting structures on the diverter assembly 3 have the same size at the same height; It is understandable that the supporting structures can be arranged arbitrarily on the plane as long as the axisymmetry requirement is met; It should be noted that at least one set of support structures is pressed tightly against the flow plate, and any set of support structures cannot contact the input cover 5 .

[0035] See also Figure 3 As shown, it is a top view of the diversion component of the embodiment of the present invention. Figure 1 Top-down and Figure 3 Corresponding view, Figure 1 There are 4 sets of support structures from top to bottom, corresponding to Figure 3 A plurality of support structures are provided from top to bottom in the middle, and optionally, the second group of support structures is provided as a group of support plates to form a Figure 1 Medium pressure is isolated on the flow plate; During assembly, the transverse plate should be pressed integrally onto the flow plate and the housing to form the upper and lower parts of the second flow cavity.

[0036] If the above conditions are met, the support structure on the diversion component can be replaced by: A plurality of evenly distributed guide vanes, at least one of which is pressed against the flow plate to form a second liquid passage cavity 14 divided into two sections; A plurality of support plates are arranged in a honeycomb shape, wherein at least one group of honeycombs is pressed tightly against the flow plate.

[0037] Specifically, the flow plate 2 is provided on the output bin 12, and the flow hole 21 is provided on a side close to the liquid inlet 111; The effluent filter membrane 42 and the flow plate 2 form a second liquid passage cavity 14. The second liquid passage cavity 14 is partitioned by the flow diversion assembly 3 and the flow plate 2, and is divided into an upper portion and a lower portion, i.e., a second liquid passage cavity upper portion 141 and a second liquid passage cavity lower portion 142. The flow hole 21 is located at the upper portion, and the flow hole 21 itself is not separated.

[0038] The support structure of the diversion assembly 3 is designed to create a height difference, giving the inlet filter membrane 41 a dome-like slope, with a higher center and lower edges. This structure significantly increases the contact area between the liquid and the filter membrane, while also guiding the fluid to diffuse naturally, reducing turbulence and dead spots, and ensuring uniform filtration.

[0039] Specifically, the input chamber is used to receive the filtered liquid, and the liquid inlet filter membrane 41 forms an inclined surface with the diversion component 3 to increase the contact area between the filter membrane and the liquid, thereby improving the filtering efficiency.

[0040] Specifically, the inclined surface is formed by the height difference of the supporting structure, and the central area of ​​the liquid inlet filter membrane 41 is higher than the edge area, forming a bulge-like structure protruding toward the input cover 5 .

[0041] Specifically, the flow holes 21 are concentrated in the upper center area of ​​the flow plate 2, and all the flow holes 21 are located above the partition; Please cooperate Figure 1 See Figure 2 As shown in the figure, The output cover 6 and the flow plate 2 form an output chamber, which communicates with the second liquid passage cavity 14 and the liquid outlet 121 .

[0042] The output cover 6 is also provided with corresponding exhaust holes 61 for exhausting the air in the filter.

[0043] The support structure precisely supports the dual-layer filter membranes, forming a stable first liquid-passing cavity 13. The second liquid-passing cavity 14, formed by the flow plate 2 and the effluent filter membrane 42, is partitioned into upper and lower sections. This design maintains the cavity's shape and, combined with the concentrated distribution of the flow holes 21 in the upper center, achieves directional flow guidance and prevents liquid stagnation.

[0044] Specifically, the inlet filter membrane 41 and the outlet filter membrane 42 are configured as nucleopore membranes.

[0045] See also Figure 4 As shown, it is a schematic diagram of the liquid flow of an embodiment of the present invention. In the figure, the liquid flow entering the filter flows in sequence of A→B→C→D→E.

[0046] See also Figure 4 As shown, it is a schematic diagram of the filter membrane working process of an embodiment of the present invention, please refer to Figure 5 Figure (a) is a schematic diagram of the membrane filter workflow. In the figure, the liquid flows into the filter from the liquid inlet and flows downward along the membrane. See also Figure 5 Figure (b) shows the first filtration phase of the membrane. When the liquid medicine fills the input chamber, the liquid medicine enters the first liquid passage cavity through the inlet filter membrane. The first liquid passage cavity is supported by the diversion component, and the appearance of the inlet filter membrane itself does not change. See also Figure 5 Figure (c) is a schematic diagram of the second filtration phase of the membrane operation. In the figure, the first liquid passage cavity is filled with liquid. At the same time, liquid enters the second liquid passage cavity through the outlet filter membrane. Under the pressure of the liquid, the outlet filter membrane in the lower part of the second liquid passage cavity is pressed away from the diversion assembly, and the corresponding outlet filter membrane in the upper part of the second liquid passage cavity is pulled. After the lower part of the second liquid passage cavity is filled, the air in the entire input chamber is concentrated in the upper part of the second liquid passage cavity. See also Figure 5 Figure (d) is a schematic diagram of the working liquid outlet of the filter membrane. When the input chamber is completely full, the drug liquid enters the output chamber through the flow hole. At this time, the drug liquid passes through the inlet filter membrane and the outlet filter membrane twice, and is exhausted through the second liquid cavity to complete the precision filtration.

[0047] See also Figure 6 As shown, it is a schematic diagram of the membrane termination process according to an embodiment of the present invention; When the liquid stops flowing, the liquid inlet is cut off. At this time, due to the remaining liquid in the infusion tube, such as Figure 5 As shown in Figure (a), it is a schematic diagram of the start of flow interruption, and the filter is still full of liquid medicine; See also Figure 6 Figure (b) is a schematic diagram of the middle section of the flow interruption. After a period of cessation, the liquid in the input and output chambers is completely consumed. At this time, the first and second liquid passage cavities still contain liquid due to the surface tension of the liquid in the filter membrane. See also Figure 6 Figure (c) is a schematic diagram of flow interruption termination. In the figure, the effluent filter membrane corresponding to the lower part of the second liquid-passing cavity is adsorbed and returns to the corresponding position in contact with the diversion component, isolating the lower part of the second liquid-passing cavity. At the same time, the liquid corresponding to the upper part of the second liquid-passing cavity is no longer replenished after it flows out.

[0048] In this state, if the infusion is continued, the lower part of the second liquid-transfer cavity is filled with liquid medicine, so no air is added. At the same time, the air brought in by the liquid medicine can be discharged into the upper part of the second liquid-transfer cavity more quickly.

[0049] See also Figure 7 As shown, it is a method for preparing the medical filter of the present invention, comprising: Prepare the housing, flow plate and sealing cover; and forming a filtration group consisting of an outlet filter membrane, a diversion component, and an inlet filter membrane; Assemble the filter; When forming a filter group, include: Step S1, cutting the effluent filter membrane and the inlet filter membrane, and pressing the edges of the effluent filter membrane and the inlet filter membrane to form a filter bag; Step S2, opening the filter bag and placing the diversion assembly into the filter bag; and Arrange the filter bag so that the opening of the filter bag is at the preset opening; Step S3, pressing the filter group toward the flow plate so that the edge of the filter bag is pressed tightly against the housing, with the opening located between the flow plate and the diversion assembly; The preset opening is arranged parallel to the supporting structure of the diversion component, and the size of the opening is not greater than 1 / 3 of the circumference of the diversion component.

[0050] It should be noted that if the opening is too large, the first liquid passage cavity formed between the inlet filter membrane and the outlet filter membrane will be difficult to seal effectively, and the filter membrane may not function properly during use.

[0051] In step S1, when cutting the effluent filter membrane, the effluent filter membrane is cut into an elliptical shape, the minor axis of which is not less than the diameter of the flow plate, the major axis of which is not less than the diameter of the housing, and is not greater than 1.5 times the horizontal projection diameter of the diversion component; When cutting the inlet filter membrane, the inlet filter membrane is cut into a circular shape, the diameter of which is not less than the diameter of the shell and not larger than the long axis of the outlet filter membrane; When forming the filter bag, the corresponding surface of the inlet filter membrane is pressed against the outlet filter membrane; The preset opening is opened at a position corresponding to the long axis of the outlet filter membrane; When assembling the filter, the filter group is formed into a disc-shaped filter group after being supported by the diversion component, and the filter group is pressed against the flow plate, and the edge of the liquid inlet filter membrane is pressed into the filter housing to complete the assembly.

[0052] In step S2, in order to match the support structures of different lengths provided on the diversion assembly, the position where the long axis of the effluent filter membrane is located is opened, so that the diversion assembly as a whole can be placed in the corresponding position. At the same time, Because the size of the filter bag is slightly larger than the diversion assembly, the supporting structures of the diversion assembly can support several separated areas in the filter bag to form a first liquid-passing cavity inside the filter bag, and press on the flow plate to form the upper and lower parts of the second liquid-passing cavity.

[0053] See also Figure 8 As shown, it is a schematic diagram of the assembly groove of an embodiment of the present invention. In this embodiment, in order to better assemble, the following methods can be selected to position the filter group: Optionally, a horizontal flow plate groove 22 is provided under the flow hole 21 on the flow plate 2, and a longitudinal groove is provided on the outer shell to match the flow plate groove, so as to press the horizontal support structure or support plate in the filter group into the above-mentioned groove, and use the groove to press the filter membrane on the outside of the support structure or support plate.

[0054] Optionally, a housing groove 15 is provided on the filter chamber 1 of the housing, the depth of the groove being not less than the thickness of the filter membrane and not greater than the difference between the maximum diameter of the filter group and the minimum diameter of the filter chamber 1; During assembly, the diverter assembly presses the edge of the inlet filter membrane into the housing groove 15 .

[0055] It should be noted that during assembly, because the wrapping direction of the edge of the liquid inlet filter membrane on the diversion assembly is opposite to the extrusion direction of the diversion assembly, the diversion assembly should be placed above the filter bag and the edge of the diversion assembly should be wrapped with the edge of the liquid inlet filter membrane as much as possible to prevent the liquid inlet filter membrane from slipping after assembly is completed.

[0056] When assembling the filter, the following steps are also included: Clean air is poured into the filter group through its opening; When the filter group is inflated, press the inflated filter group into the corresponding position of the housing.

[0057] The filter group is formed by wrapping the diversion component 3 with a softened composite membrane. Heat pressing creates indentations and folds that conform to the contours of the support structure. This one-piece construction reduces the number of components required, while the indentations closely align with the support structure, enhancing sealing and reducing the risk of leakage.

[0058] It should be noted that in this plan: When preparing the filter membrane, the base membrane and non-woven fabric are pressed together to form a composite membrane. The optional base material is usually polycarbonate (PC), polyester (PET) or polyethersulfone (PES) film (usually 5-20μm thick); Optionally, during preparation, the above substrate may be modified to enhance its performance.

[0059] It is important to note that the filter group should be disinfected before assembly.

[0060] As you can understand, the Nucleopore membrane material possesses high-precision filtration properties. The clean air infusion during the preparation process and the final sterilization step ensure that the membrane is sterile and free of particle shedding. The overall design meets the stringent biosafety and reliability requirements of medical filters, and I will not elaborate further here.

[0061] See also Figure 1 During assembly, the filter group consisting of composite membrane-diverter assembly-composite membrane manufactured in the above manner is used. The filter group includes an inlet filter membrane 41, a diverter assembly 3 and an outlet filter membrane 42. At this time, due to the injection of air, the filter group is composed of Figure 2 The shape shown in the middle filter membrane 4 has an overall appearance of a dish with two raised sides, and the raised sides are supported by the support structure in the diversion assembly 3; At this time, press the filter group into the filter chamber, and press the support structure at the center of the filter group and the flow plate in the filter chamber tightly.

[0062] It is understandable that the filter membrane that has not been processed by the above-mentioned processing method cannot be combined with the diversion component. At this time, it may cause the filter membrane to fall off, resulting in the problem of being unable to effectively perform a second filtration during subsequent use.

[0063] At the same time, in order to solve the problem of using only a single-layer filter membrane for filtration in the prior art, the present invention provides a filter group with a double-layer filter membrane in a form away from the sealing cover of the filter box. At the same time, in order to avoid the problem of filter membrane adhesion leading to a decrease in filtration effect and filtration efficiency, the present invention provides a corresponding diversion component to avoid the problem of filter membrane adhesion; However, due to the provision of a diversion component, tiny bubbles originating from the medicinal liquid will be filtered by the filter membrane and adsorbed on the inlet filter membrane or the outlet filter membrane, affecting the liquid discharge effect. The present invention provides several inclined filtering surfaces so that these bubbles can be blocked at a position close to the bottom of the filter, which can effectively avoid the problem of poor liquid discharge effect caused by air traps.

[0064] To address the problem in the prior art that, during long-term or intermittent operation, the filter may experience poor liquid flow and affect its stability during operation, the present application provides a second liquid passage cavity at the bottom as a buffer, and utilizes the opening of the filter group to create a movable chamber that communicates with the first liquid passage cavity. During the interruption, some air is stored in the lower part of the second liquid passage cavity. When the filtration is restarted, the second liquid passage cavity intercepts some bubbles to prevent the bubbles from entering the upper part of the first liquid passage cavity, which can effectively improve the filtration efficiency when the filtration is restarted.

[0065] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0066] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A medical filter, comprising a filter chamber configured as a circular pancake structure comprising an input chamber and an output chamber, the filter chamber being arranged longitudinally, with a liquid inlet located above the input chamber and a liquid outlet located below the output chamber; and a flow diversion assembly and a flow plate disposed between the input and output chambers; It is characterized by: The two sides of the diversion component are wrapped with an inlet filter membrane and an outlet filter membrane, forming a first liquid-passing cavity supported by the diversion component for receiving the liquid filtered by the inlet filter membrane; The outlet filter membrane and the flow plate form a second liquid passage cavity for receiving the liquid filtered by the outlet filter membrane, and the second liquid passage cavity is partitioned by the diversion assembly and the flow plate, and the second liquid passage cavity is divided into an upper part and a lower part; For the effluent filter membrane, In response to the filtration being performed, the outlet filter membrane filters the liquid in the first liquid passage cavity at the upper portion of the second liquid passage cavity; In response to filtration stopping, the outlet filter membrane blocks the gas that is not exhausted during the filtration stopping at the lower portion of the second liquid-passing cavity.

2. The medical filter according to claim 1, characterized in that The diversion assembly includes a plurality of groups of support structures arranged with different lengths; Wherein, the long axis of each supporting structure is perpendicular to the corresponding plane of the flow plate; For each support structure that has the same vertical distance from the liquid inlet, the lengths thereof are the same; The inlet filter membrane and the outlet filter membrane are supported by the support structure and form the first liquid passage cavity.

3. The medical filter according to claim 2, characterized in that Also included are an input cover and an output cover for sealing the filter bin; The flow plate is arranged on the output bin and has a flow hole, and the flow hole is arranged on a side close to the liquid inlet; The flow hole is located at the upper part of the second liquid passage cavity, and the flow hole itself is not separated by the partition.

4. The medical filter according to claim 3, characterized in that The input chamber is used to receive the filtered liquid, and the liquid inlet filter membrane forms an inclined surface with the diversion component to increase the filtering area; Wherein, the liquid inlet filter membrane filters the liquid once in the filtering state; During the primary filtration, the input chamber is gradually filled with liquid and flows into the first liquid passage cavity.

5. The medical filter according to claim 4, characterized in that The inclined surface is supported by the supporting structure and formed by the height difference of each supporting structure. The central area of ​​the liquid inlet filter membrane is higher than the edge area, forming a ridge-like structure protruding toward the input cover.

6. The medical filter according to claim 3, characterized in that The flow holes are concentrated in the upper center area of ​​the flow plate, and all the flow holes are located above the partition; The output cover and the flow plate form an output chamber, and the output chamber is connected with the second liquid passage cavity and the liquid outlet.

7. The medical filter according to claim 3, characterized in that The effluent filter membrane filters the liquid filtered by the effluent filter membrane to perform secondary filtration; In the filtering state, the upper portion of the second liquid passage cavity receives the filtered liquid, and the liquid flows into the output bin through the flow hole.

8. The medical filter according to any one of claims 1 to 7, characterized in that: The inlet filter membrane and the outlet filter membrane are configured as nuclear pore membranes.

9. A method for preparing a medical filter, comprising: Prepare the housing, flow plate and sealing cover; as well as forming a filtration group consisting of an outlet filter membrane, a diversion component, and an inlet filter membrane; Assemble the filter; It is characterized in that, when forming the filter group, it includes: Step S1, cutting the effluent filter membrane and the inlet filter membrane, and pressing the edges of the effluent filter membrane and the inlet filter membrane to form a filter bag; Step S2, opening the filter bag and placing the diversion assembly into the filter bag; and Arrange the filter bag so that the opening of the filter bag is at the preset opening; Step S3, pressing the filter group toward the flow plate so that the edge of the filter bag is pressed tightly against the housing, and the opening is located between the flow plate and the diversion assembly; Wherein, the preset opening is arranged parallel to the supporting structure of the diversion component, and the opening size is not greater than 1 / 3 of the circumference of the diversion component.

10. The method for preparing a medical filter according to claim 9, characterized in that: In step S1, when cutting the effluent filter membrane, the effluent filter membrane is cut into an elliptical shape, the minor axis of which is not less than the diameter of the flow plate, the major axis of which is not less than the diameter of the housing, and not greater than 1.5 times the horizontal projection diameter of the diversion component; When cutting the inlet filter membrane, the inlet filter membrane is cut into a circular shape, the diameter of which is not less than the diameter of the shell and not larger than the long axis of the outlet filter membrane; When forming the filter bag, the corresponding surface of the inlet filter membrane is pressed against the outlet filter membrane; The preset opening is opened at a position corresponding to the long axis of the outlet filter membrane; When assembling the filter, the filter group is formed into a disc-shaped filter group by being supported by the diversion component, and the filter group is pressed toward the flow plate, and the edge of the inlet filter membrane is pressed into the outer shell of the filter to complete the assembly.

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