Flexible flat-plate leukocyte reduction filter having radial flow field and use thereof

Abstract

Disclosed in the present invention are a flexible flat-plate leukocyte reduction filter having a radial flow field and use thereof. The flexible flat-plate leukocyte reduction filter having a radial flow field can diffuse blood raw materials by means of radial flow and cause the blood raw materials to uniformly pass through an annular filter membrane layer. The flexible flat-plate leukocyte reduction filter having a radial flow field of the present invention has a simple structure, and can effectively increase the filtration speed and reduce the residual space inside the blood.

Description

Flexible flat-plate leukocyte reduction filter with radial flow field and its application Technical Field

[0001] This invention relates to a blood filter, and more particularly to a leukocyte reduction filter, relating to a blood processing device, specifically a flexible flat-plate leukocyte reduction blood filter with a radial flow field that utilizes a radial flow path to improve filtration efficiency, reduce blood residue, and shorten processing time. Background Technology

[0002] In the modern medical field, blood processing is a very important and complex technology. In addition, blood is a non-Newtonian fluid, making the design of blood filters even more difficult to improve. Among the current filters, how to effectively reduce white blood cells is an important issue. At present, flat filters are the main type, but they have problems such as limited filtration area, low efficiency, large blood residue, and long filtration time, which urgently need to be solved.

[0003] Referring to Figures 1 and 2 (US Patent Application No. USA-20230099894A1), this patent is for a flat plate filter. The filtration method involves passing the filter membrane from one side of the plate to the other. The blood raw material inlet is located on the side of the plate slightly above the center, while the outlet is located on the other side of the plate slightly below the center. The disadvantage of this design is that it limits the maximum area of ​​the filter membrane to the area of ​​the plate, and the filtrate is very easy to accumulate at the outlet, resulting in residual liquid.

[0004] Referring again to Figures 3 and 4 (US Patent Application No. US 8,857,627 B2), this is also a flat-plate filter. The method involves blood entering from one side of the flat plate, with the inlet located slightly above the center of the plate on the same side. The blood passes through a filter membrane to the other side, generating a primary filtrate. This primary filtrate then undergoes a second filtration through a lower filter membrane to generate a secondary filtrate, which returns to the outlet on the same side as the inlet. However, the outlet is located slightly below the center of the plate on the same side as the inlet to output the secondary filtrate. Similarly, the disadvantages of this design are that the maximum area of ​​the filter membrane is limited to the flat plate area, and due to the outlet design, filtrate easily accumulates at the outlet, resulting in residual liquid.

[0005] Furthermore, the problem with traditional designs lies in the physical limitations of space utilization and filtration efficiency: existing filter designs determine filtration capacity based on "planar area," which presents a non-linear contradiction between volume and area. To improve filtration efficiency, the membrane area must often be increased. However, in a flat structure, increasing the area means that the outer shell diameter must be radially enlarged, resulting in an abnormally bulky filter. This not only increases packaging, storage, and transportation costs but also occupies the limited operating space of blood processing centers. In addition, since the filter operates by using gravity to allow blood to pass vertically downward through the filter layer, the internal structure of traditional filters must reserve space for blood entry and exit. Due to gravity, blood tends to accumulate in the lower half of the filter, causing the upper membrane to be underutilized. Therefore, within the same volume, the effective filtration path is quite limited, resulting in inefficient space utilization.

[0006] Secondly, blood is a non-Newtonian fluid that is extremely sensitive to shear forces, making blood flow rate control crucial. Excessive flow will damage red blood cells, while insufficient flow can lead to blood clotting. Therefore, blood filters cannot be designed like those used for filtering water or other substances. However, traditional blood filters often suffer from uneven pressure and hemolytic risks due to issues with blood flow control. Uneven pressure creates a centripetal high-pressure phenomenon, meaning that when blood enters the flat chamber, the pressure is highly concentrated in the central region of the filter membrane due to the jet effect at the inlet, resulting in a "high pressure in the center, low pressure at the edges" phenomenon. This uneven filtration speed causes the central filter pores to become clogged prematurely due to prolonged overload. Furthermore, when blood is forced to squeeze through the filter membrane pores under high pressure, the localized high shear force directly damages the red blood cell membrane, leading to hemolytic damage. Traditional structures cannot provide a buffer, and this pressure fluctuation easily causes red blood cell rupture, leading to an increase in free hemoglobin and severely affecting the shelf life and clinical safety of blood products.

[0007] Furthermore, due to the inability of the streamlined design to cover the corners or edges of traditional shell structures, dynamic stagnation dead zones often form. These dead zones not only waste blood but also lead to microclotting and thrombosis during the filtration process. Moreover, for precious donated blood resources, the residual amount in these dead zones, due to the characteristics of traditional shell structures, is one of the main reasons for low blood recovery rates. In some hardware designs, the rigidity of the shell prevents physical expulsion after filtration, resulting in resource waste and causing significant economic losses that the industry urgently needs to address.

[0008] On the other hand, traditional shell structure designs suffer from an "airlock" effect, resulting in incomplete venting due to gas blockage. During the pre-filling stage, existing air easily becomes trapped between the filter membrane surface and the shell, forming microbubbles that aggregate into an air film, obscuring the filtration area and reducing the effective area. This is one of the most difficult problems to overcome in clinical operation of leukocyte reduction filters. Furthermore, when airlock occurs, blood can only pass through unobstructed areas, reducing the effective filtration path and indirectly increasing the load on the effective filter area, increasing the risk of leukocyte penetration and leading to instability in leukocyte reduction. To address the shortcomings caused by residual amounts and airlock, current solutions often involve manually flipping and tapping traditional filters during filtration. However, this easily increases operational variables and raises the potential risk of aseptic packaging damage or contamination.

[0009] Therefore, overcoming the various shortcomings of traditional white blood cell removal filters, such as low space efficiency, uneven pressure distribution, susceptibility to air lock, and high blood residue, in order to achieve optimized blood quality has become a major issue that the industry urgently needs to address. Summary of the Invention

[0010] To address the problems of existing filters, this invention provides a flexible flat-plate leukocyte reduction filter with a radial flow field and its application. By using a radial flow field design, and simultaneously improving the design to prevent hardware damage during centrifugation, the problems of traditional leukocyte reduction filters are overcome.

[0011] This invention provides a flexible flat-plate leukocyte reduction filter with a radial flow field, comprising: two outer shells flatly attached to each other; two filter layers flatly attached to each other and disposed between the inner surfaces of the two outer shells, wherein the two filter layers are joined with the edges of the two outer shells to form a joint; a first filter media receiving space formed between the inner surfaces of the two outer shells, the outer surfaces of the two filter layers, and the joint; and a filter layer partition column formed between the inner surfaces of the two filter layers, wherein the inner surfaces of the two filter layers, the filter layer partition column, and the joint are connected. The system forms a blood raw material containing space and a second filter material containing space. Here, the blood raw material diffuses radially from the inside to the outside of the blood raw material containing space to the inner surfaces of the two filter layers. At the same time, the pressure difference between the inside and outside of the two filter layers causes a first filtration to form a first filter material, which is then introduced and collected in the first filter material containing space. The first filter material diffuses radially from the outside to the inside of the two filter layers for a second filtration. At the same time, the pressure difference between the inside and outside of the two filter layers causes a second filtration to form a second filter material, which is then introduced and collected in the second filter material containing space.

[0012] In some embodiments of the present invention, the blood raw material accommodating space and the second filter material accommodating space are located in the middle of the flexible flat plate type leukocyte reduction blood filter, and are sequentially separated into upper and lower positions by the filter layer separating column.

[0013] As some embodiments of the present invention, it also includes a feed tube having a first feed tube portion and a second feed tube portion. The first feed tube portion has a feed tube inlet, and the second feed tube portion has a plurality of feed tube outlets. The second feed tube portion passes through the connecting portion between the two filter layers and communicates with the blood raw material containing space, so that the blood raw material is introduced from above through the feed tube inlet and enters the blood raw material containing space through the plurality of feed tube outlets.

[0014] As some embodiments of the present invention, it also includes a discharge pipe having a first discharge pipe portion and a second discharge pipe portion. The first discharge pipe portion has a plurality of discharge pipe inlets, and the second discharge pipe portion has a discharge pipe outlet. The first discharge pipe portion passes through the connecting portion between the two filter layers and communicates with the second filter material receiving space. Thereby, the second filter material is guided from the second filter material receiving space to the plurality of discharge pipe inlets of the first discharge pipe portion and discharged from below through the discharge pipe outlet.

[0015] The present invention also provides a blood filtration method for leukopenia, comprising:

[0016] A flexible flat-plate leukocyte reduction filter is provided, comprising a housing, a filter module disposed within the housing, wherein the filter module has a first flow channel located at the center of the inner side of the filter module, a second flow channel surrounding the outer periphery of the filter module, and a sealing structure that is tightly connected to and seals the filter module and the housing to form the first flow channel; and blood raw materials are uniformly diffused radially from the first flow channel to the second flow channel outside the filter module by pressure difference, thereby filtering the blood raw materials to produce filtrate, which flows into the bottom of the second flow channel.

[0017] As some embodiments of the present invention, the flexible flat-plate leukocyte reduction filter further comprises:

[0018] The filtration module has multiple stacked filtration units; an inlet pipe, which is an axial flow guide assembly for establishing the axial or central input / output path of fluid within the filter and supporting the filtration units, wherein the upper part of the inlet pipe is the inlet for blood raw materials, the lower part of the inlet pipe is located in the first flow channel, and the lower part of the inlet pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the blood raw materials pass through the filtration unit; the filtration module has inner and outer filtration partitions, and at least one elastic or soft sealing partition with compressibility, and a surrounding filtration unit is disposed between the inner and outer partitions; and an outlet pipe, which is an axial flow guide assembly, the lower part of the outlet pipe is the outlet for the filtrate, and the upper part of the outlet pipe is located at the bottom center of the second flow channel, wherein the upper part of the outlet pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the filtrate is discharged.

[0019] As some embodiments of the present invention, the filter module and the sealing structure separate the internal space of the housing into a central area and a peripheral area. The central area is located at the center of the internal space of the housing, and the peripheral area surrounds the central area in the internal space of the housing to form a concave space. The first flow channel is located in the central area, and the second flow channel is located in the peripheral area.

[0020] The present invention also provides a flexible flat-plate leukocyte reduction filter with a radial flow field, comprising: two outer shells, which are flatly and sealed to each other to form a housing, and the edge portions of the two outer shells are joined together to form a housing joint; two filter layers, which are flatly and sealed to each other, and the two filter layers are disposed between the inner sides of the two outer shells, wherein the two filter layers are joined with the edge portions of the two outer shells to form a joint; the filter layer joint is formed by the bottom edges of the two filter layers joining together.

[0021] The blood raw material containing space is formed by the inner sides of the two filter layers and the sealing of the filter layer joint; the filter material containing space is formed by the inner sides of the two outer shells, the outer sides of the two filter layers, the filter layer joint, the outer shell joint, and the sealing of the joint. The blood raw material diffuses radially from the blood raw material containing space to the two filter layers by means of the pressure difference between the inner and outer sides of the two filter layers to perform filtration and form filter material. The filter material flows downward along the inner sidewall of the shell and is introduced and collected in the filter material containing space.

[0022] As some embodiments of the present invention, the filter layer joint and the two filter layers divide the internal space of the housing into a central area and a peripheral area. The central area is located at the center of the internal space of the housing, and the peripheral area surrounds the central area in the internal space of the housing to form a concave space. The blood raw material accommodating space is located in the central area, and the filter material accommodating space is located in the peripheral area.

[0023] As some embodiments of the present invention, it also includes a feed pipe having a feed pipe inlet and a feed pipe outlet for introducing blood raw materials into the blood raw material receiving space, wherein the feed pipe passes through the joint from the middle position of the top of the housing and communicates with the blood raw material receiving space.

[0024] As some embodiments of the present invention, a discharge pipe is also included, having a discharge pipe inlet and a discharge pipe outlet. The discharge pipe inlet passes through the middle of the bottom of the housing space, through the housing joint portion, and communicates with the filter media receiving space, so that the filter media can be discharged from the filter media receiving space through the discharge pipe from the housing.

[0025] The present invention also provides a blood filtration method for leukopenia, comprising: providing a flexible flat-plate leukopenia filter, including a housing and a filter module disposed within the housing, wherein the filter module has a first flow channel located at the center of the inner side of the filter module, a second flow channel located around the outer periphery of the filter module, and a partition column located in the first flow channel inside the filter module, thereby separating and sealing the upper part of the first flow channel as a blood raw material accommodating space and the lower part of the first flow channel as a secondary filtrate accommodating space; the blood raw material flows radially outward from the blood raw material accommodating space to the filter module for a first filtration to generate the primary filtrate and collect it in the second flow channel; and the primary filtrate flows radially inward from the second flow channel to the filter module for a second filtration to generate the secondary filtrate and collect it in the secondary filtrate accommodating space.

[0026] As some embodiments of the present invention, the flexible flat-plate leukocyte reduction filter further comprises:

[0027] The filtration module has multiple stacked filtration units; an inlet pipe for introducing blood raw materials into the blood raw material receiving space, the inlet pipe being an axial flow guide assembly for establishing the axial or central input / output path of the fluid within the filter and supporting the filtration unit, wherein the upper part of the inlet pipe is located at the top center of the housing, the lower part of the inlet pipe is located in the first flow channel, and the lower part of the inlet pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the blood raw materials pass through the filtration unit; the filtration module has inner and outer filtration partitions, and at least one elastic or soft sealing partition with compressibility, and a surrounding filtration unit is disposed between the inner and outer partitions; and an outlet pipe for discharging the secondary filtrate, the outlet pipe being an axial flow guide assembly, the lower part of the outlet pipe being the outlet of the filtrate, and the upper part of the outlet pipe being located at the bottom center of the second flow channel, wherein the upper part of the outlet pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the filtrate is discharged.

[0028] In some embodiments of the present invention, the blood raw material containing space and the secondary filtrate containing space are located in the middle of the flexible flat plate type leukocyte reduction blood filter, and are sequentially separated into upper and lower positions by the dividing column.

[0029] One objective of this invention is to provide a filtration path with a radial flow field. The central flow channel design allows blood to flow from the inlet pipe into a distribution channel located at the center of the filter. Upon entering, the blood is pressurized and diffuses radially through the distribution channel at the center of the filter, passing through symmetrically arranged filter membrane layers for filtration. The filtered blood collects in the external channel between the filter membrane and the outer shell, forming a radial flow field from the inside out, and finally flows out from the bottom outlet. Accordingly, the radial flow field of this invention optimizes pressure distribution, making the flow pressure distribution more uniform and avoiding the formation of dynamic stagnation dead zones. In particular, it effectively reduces the pressure stress on the filter membrane and reduces pressure unevenness and fluctuations, thereby reducing physical damage to red blood cells (low hemolysis rate). In contrast, existing prior art structures cannot control flow velocity and pressure, causing blood to tend to flow towards areas of lower pressure, resulting in uneven flow velocity. Because the outer circumference of the filter membrane has a larger surface area than its inner circumference, this "radial diffusion from the inner center to the outside" method significantly increases the initial filtration contact area. The larger inflow surface area effectively reduces the leukocyte density on the filter membrane surface, delaying the membrane clogging effect and thus reducing filtration resistance. This is particularly effective for processing blood products with high leukocyte concentrations. Furthermore, the radial flow field structure of this invention allows the outer circumferential surface of the filter membrane to be completely wetted by blood at the initial startup stage, thereby eliminating airlock and preventing the filtration area from shrinking due to air accumulation.

[0030] Another object of the present invention is to provide a filter layer separator column to form a multiple radial diffusion pattern, which allows the aforementioned filtered blood to be filtered again. The present invention allows blood to enter a first flow channel from an inlet located at the center of the filter, and then undergo a first radial filtration through left and right filter membranes. Through radial diffusion "from the inside out," the blood material flows radially from the first flow channel at the center of the filter through the upper half of at least one filter membrane to a second channel located outside the membrane inside the filter. During this process, white blood cells are trapped or adsorbed in the upper half of the filter membrane. The primary filtrate from the upper half of the filter membrane re-converges in the second channel and is then guided from the second channel through radial diffusion "from the outside in" to the lower half of the filter membrane for a second radial dispersion filtration. Accordingly, the primary filtrate again radially enters the lower half of the filter membrane, where it further traps or adsorbs remaining white blood cells, forming a secondary filtrate, which continues to converge into a third flow channel at the center of the filter and flows downwards through the outlet of the third flow channel, exiting from the bottom of the filter. The multiple radial diffusion method of this invention is a design of parallel radial dispersion flow and series filter membrane: the parallel radial dispersion flow can increase the flow rate of blood raw materials and reduce filtration time without disrupting the flow rate of red blood cells; the series filter membrane design can utilize more filter membrane surface area in a limited volume for efficient filtration, allowing platelets and red blood cells to pass through the filter membrane evenly. The two parallel filter membranes can not only increase the effective filtration area of ​​the filter, but also increase the throughput of the filtrate.

[0031] Another objective of this invention is to adopt a structure in which blood is introduced from the center of the top of the shell and filtrate is discharged from the center of the bottom of the shell, which can reduce dead corners inside the structure, effectively reduce the amount of blood residue, and improve the red blood cell recovery rate.

[0032] Another objective of this invention is to provide a filter housing with a highly flexible structure. When subjected to high-speed centrifugal force during the blood component centrifugation preparation method, the flexible soft shell structure of this invention can deform with the centrifuge cup wall and uniformly distribute stress, effectively avoiding the risk of breakage caused by stress concentration, which is common in rigid shells. This ensures the aseptic integrity and operational safety of blood products during the centrifugation process. Attached Figure Description

[0033] Figure 1 is a schematic diagram of a wide planar structure, one of the existing technologies.

[0034] Figure 2 is a schematic diagram of a narrow face of one of the existing technologies.

[0035] Figure 3 is a schematic diagram of a wide plane in one of the prior art.

[0036] Figure 4 is a schematic diagram of a narrow face of one of the existing technologies.

[0037] Figure 5 is a perspective view of a cross-section along the longitudinal direction of one of the present inventions.

[0038] Figure 6 is a perspective view of a cross-section along the longitudinal direction of one of the present inventions.

[0039] Figure 7 is a perspective view of a cross-section along the longitudinal direction of one of the present inventions.

[0040] Figure 8 is a perspective view of a cross-section along the longitudinal direction of one of the present inventions.

[0041] Figure 9 is a flowchart of a method according to an embodiment of the present invention.

[0042] Figure 10 is a perspective view of a cross-section along the longitudinal direction of one of the present inventions.

[0043] Figure 11 is a perspective view of a cross-section along the longitudinal direction of one of the present inventions.

[0044] Figure 12 is a flowchart of a method according to another embodiment of the present invention.

[0045] Reference numerals: 2000: Flexible flat-plate filter for removing white blood cells with radial flow field; 2100: Housing; 2150: First filter media receiving space; 2200: Filter layer; 2220: Filter layer separator; 2250: Blood raw material receiving space; 2260: Second filter media receiving space; 2300: Feed pipe; 2310: First part of feed pipe; 2311: Feed pipe inlet; 2320: Second part of feed pipe; 2321: Feed pipe outlet; 2400: Discharge pipe; 2410: First part of discharge pipe; 2411: Discharge pipe inlet; 2420: Second part of discharge pipe; 2421: Discharge pipe outlet; 2500: Joint; 2700: Step: A flexible flat-plate filter with radial flow field... Leukocyte Reduction Filtration Method 2710: Step 1: Blood raw material is introduced through the first part 2310 of the feed pipe and enters the blood raw material receiving space 2250 through the multiple feed pipe outlets 2321 of the second part 2310 of the feed pipe. Step 2720: The blood raw material fills the blood raw material receiving space 2250 and diffuses to the outside of the two filter layers 2210. At the same time, the blood raw material is filtered by the pressure difference between the inside and outside of the two filter layers 2210 to form the first filter material, which is then introduced and collected in the first filter material receiving space 2150. Step 2730: The first filter material flows downward from the first filter material receiving space 2150 along the two outer shells 2100. Step 2740: The first filter material fills the first filter material receiving space. Space 2150, and the outer side of the two filter layers 2210 of the second filter media receiving space 2260, at the same time, by means of the pressure difference between the inner and outer sides of the two filter layers 2210, a radial flow is formed in all directions from the outside to the inside in 360 degrees. The first filter media forms the second filter media and is introduced and collected in the second filter media receiving space 2260 2750: Step: The second filter media is guided from the second filter media receiving space 2260 to the multiple discharge pipe inlets 2411 of the first part of the discharge pipe 2410, and discharged through the discharge pipe outlet 2421 of the second part of the discharge pipe 2420 3000: Flexible leukocyte reduction filter with radial flow field 3100: Housing 3130: Filter media receiving space 3200: Filter layer 3230: Blood raw material holding space; 3300: Feed pipe; 3310: Feed pipe inlet; 3320: Feed pipe outlet; 3400: Discharge pipe; 3410: Discharge pipe inlet; 3420: Discharge pipe outlet; 3500: Joint; 3520: Outer shell joint; 3530: Filter layer joint; 3700: Step: Blood filtration method for leukocyte reduction using a flexible filter with radial flow field; 3710: Step: Blood raw material is introduced through the feed pipe 3300 and enters the blood raw material holding space 3230; 3720: Step: The blood raw material fills the blood raw material holding space 3230, and simultaneously diffuses to the outside of the two filter layers 3200 due to the pressure difference between the inner and outer sides of the two filter layers 3200.Filtering blood raw materials to form filter media, and introducing it into the filter media receiving space 3150 3730: Step: The filter media flows downward from the filter media receiving space 3150 along the two outer shells 3100 3730 3740: Step: The filter media flows from the filter media receiving space 3150 to the discharge pipe 3400, and is discharged through the discharge pipe 3400. Detailed Implementation

[0046] This invention focuses on a flexible flat-plate leukocyte reduction filter. To provide a thorough understanding of the invention, detailed structures, components, and method steps are presented in the following description. Clearly, the implementation of this invention is not limited to the specific details familiar to those skilled in the art. Furthermore, well-known structures and components are not described in detail to avoid unnecessarily limiting the invention. In addition, to provide a clearer description and to enable those skilled in the art to understand the invention, the parts in the illustrations are not drawn according to their relative dimensions; some dimensions are exaggerated to highlight their proportions to other relevant scales, and irrelevant details are not fully drawn for the sake of simplicity. Preferred embodiments of the invention will be described in detail below; however, in addition to these detailed descriptions, the invention can be widely implemented in other embodiments, and its scope is not limited, as defined by the claims.

[0047] As shown in Figures 5 to 9, an embodiment of the present invention provides a flexible flat-plate leukocyte reduction filter 2000 with a radial flow field, comprising two housings 2100, two filter layers 2200, an inlet pipe 2300, an outlet pipe 2400, and a connecting portion 2500. The inlet pipe 2300 further includes a first inlet pipe portion 2310 and a second inlet pipe portion 2320. The first inlet pipe portion 2310 further includes an inlet pipe inlet 2311. The second inlet pipe portion 2320 further includes a plurality of inlet pipe outlets 2321. The outlet pipe 2400 further includes a first outlet pipe portion 2410 and a second outlet pipe portion 2420. The first outlet pipe portion 2410 inlet pipe further includes a plurality of outlet pipe inlets 2411. The second outlet pipe portion 2420 further includes an outlet pipe outlet 2421. The two filter layers 2200 are flatly attached to each other, and the two outer shells 2100 are flatly attached to each other. The filter layer 2210 is disposed between the inner surfaces of the two outer shells 2110, and the edges of the filter layer 2210 and the two outer shells 2100 are joined together to form a joint 2500. Filter layer separators 2220 are formed between the inner surfaces of the two filter layers 2210, and the inner surfaces of the two filter layers 2210, the filter layer separators 2220, and the joint 2500 form a blood raw material receiving space 2250 and a second filter material receiving space 2260. The second part 2320 of the feed pipe 2300 passes through the joint 2500 between the two filter layers 2210 and communicates with the blood raw material receiving space 2250. The first part 2410 of the discharge pipe 2400 passes through the joint 2500 between the two filter layers 2210 and communicates with the second filter material receiving space 2260. The first filter media receiving space 2150 is formed between the inner sides of the two outer shells 2100, the outer sides of the two filter layers 2210, and the joint 2500. The blood raw material receiving space 2250 and the second filter media receiving space 2260 are located between the flexible flat plate type leukocyte removal blood filter 2000, and are sequentially divided into upper and lower positions by the filter layer separator 2220. In this way, the blood raw material is introduced into the blood raw material receiving space 2250 from the top through the feed pipe inlet 2311, and the filter media is discharged from the lower second filter media receiving space 2260 through the discharge pipe outlet 2421.

[0048] As shown in Figures 5 to 9, according to an embodiment of the present invention, a blood filtration method 2700 for leukocyte reduction using a flexible flat-plate leukocyte reduction filter with a radial flow field is provided, comprising: providing the flexible flat-plate leukocyte reduction filter with a radial flow field as described above; introducing blood raw material through a feed pipe inlet 2311 and into a blood raw material receiving space 2250 through multiple feed pipe outlets 2321 (step 2710); filling the blood raw material receiving space 2250 with the blood raw material and undergoing a first radial diffusion from the inside out to the inner surfaces of two filter layers 2210, while simultaneously performing a first filtration by the pressure difference between the inner and outer surfaces of the two filter layers 2210 to form a first filter material, which is then introduced and collected in a first filter material receiving space 2150 (step 2720); the first filter material flows downward from the first filter material receiving space 2150 along the inner walls of the two outer shells 2100 (step 2730); the second filter material flows downward from the first filter material receiving space 2150 along the inner walls of the two outer shells 2100. A filter medium fills the first filter medium receiving space 2150 and reaches the outer side of the two filter layers 2210 located in the second filter medium receiving space 2260. The first filter medium undergoes a second radial diffusion from the outside to the inside to the inner side of the two filter layers 2210. At the same time, it undergoes a second filtration by the pressure difference between the inner and outer sides of the two filter layers 2210 to form a second filter medium, which is then introduced and collected in the second filter medium receiving space 2260. The first filter medium forms a radial flow from the outside to the inside in all directions by the pressure difference between the inner and outer sides of the two filter layers 2210, and passes through the two filter layers 2210 again to form a second filter medium, which is then introduced and collected in the second filter medium receiving space 2260 (step 2740). The second filter medium flows from the second filter medium receiving space 2260 to the multiple discharge pipe inlets 2411 of the first part of the discharge pipe 2410, and is discharged through the discharge pipe outlet 2421 of the second part of the discharge pipe 2420 (step 2750).

[0049] As shown in Figures 10 to 12, according to an embodiment of the present invention, a flexible flat-plate leukocyte reduction filter 3000 with a radial flow field is proposed, which includes two outer shells 3100, two filter layers 3200, a feed pipe 3300, a discharge pipe 3400, a filter layer junction 3530, an outer shell junction 3520, and a junction 3510. The feed pipe 3300 further includes a feed pipe inlet 3310 and a feed pipe outlet 3320. The discharge pipe 3400 further includes a discharge pipe inlet 3410 and a discharge pipe outlet 3420. The two filter layers 3200 are flatly attached to each other, and the two outer shells 3100 are flatly attached and sealed to each other to form a shell. The two filter layers 3200 are disposed between the inner sides of the two outer shells 3100, and the edge portions of the two filter layers 3200 and the two outer shells 3100 are joined together to form the junction 3510. The bottom edges of the two filter layers 3200 are joined together to form a filter layer junction 3530. The inner surfaces of the filter layers 3200, the filter layer junction 3530, and the junction 3510 are sealed to form a blood raw material receiving space 3230. The feed pipe 3300 passes through the junction 3510 from the middle of the top of the housing and connects to the blood raw material receiving space 3230. The edge portions of the two outer shells 3100 are joined together to form an outer shell junction 3520. The two outer shells 3100, the two filter layers 3200, the filter layer junction 3530, the outer shell junction 3520, and the junction 3510 form a filter media receiving space 3130. The discharge pipe inlet 3410 of the discharge pipe 3400 passes through the outer shell junction 3520 from the middle of the bottom of the inner space of the housing and connects to the filter media receiving space 3130. The filter layer junction 3530 and the two filter layers 3200 divide the internal space of the housing into a central area and a peripheral area. The central area is located at the center of the internal space of the housing, and the peripheral area surrounds the central area in the internal space of the housing to form a concave space. The blood raw material accommodating space 3230 is located in the central area, and the filter material accommodating space 3130 is located in the peripheral area.

[0050] As shown in Figures 10 to 12, according to an embodiment of the present invention, a leukocyte reduction filtration method 3700 is provided using the flexible flat-plate leukocyte reduction filter with radial flow field, comprising: introducing blood raw material through a feed pipe 3300 and into a blood raw material receiving space 3230 (step 3710); the blood raw material diffuses radially from the blood raw material receiving space 3230 to the two filter layers 3200 due to the pressure difference between the inner and outer sides of the two filter layers 3200, so as to perform filtration and form filter media; the filter media flows downward along the inner wall of the housing from the filter media receiving space 3150 (step 3730) and is introduced and collected in the filter media receiving space 3130 (step 3720); the filter media flows from the filter media receiving space 3150 to the discharge pipe 3400 and is discharged from the housing through the discharge pipe 3400 (step 3740).

[0051] As shown in Figures 10 to 12, according to an embodiment of the present invention, a flexible flat-plate leukocyte reduction filter with a radial flow field is provided, comprising: a housing; a filter module disposed within the housing, the filter module having multiple stacked filter units, a first flow channel and a second flow channel between the filter module and the housing, the first flow channel being located at the inner center of the filter module, and the second flow channel surrounding the outer periphery of the filter module, wherein blood raw material flows radially between the first flow channel and the second flow channel; and a sealing structure, the sealing structure being tightly integrated with the filter module and the housing, and sealing to form the first flow channel, thereby causing the blood raw material to diffuse uniformly towards the second flow channel outside the filter module in a radial flow manner, thereby filtering the blood raw material to produce filtrate, which flows to the bottom of the second flow channel, wherein the filter module and the sealing structure separate the internal space of the housing into a central area and a peripheral area, the central area being located at the center of the internal space of the housing, and the peripheral area surrounding the central area within the internal space of the housing to form a concave shape. The filter module comprises a central space, wherein the first flow channel is located in the central area and the second flow channel is located in the peripheral area; an inlet pipe, which is an axial flow guide assembly, is used to establish the axial or central input / output path of the fluid in the filter and the support of the filter unit, wherein the upper part of the inlet pipe is the inlet for blood raw materials, located at the top center of the housing, and the lower part of the inlet pipe is connected to the first flow channel, wherein the lower part of the inlet pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the blood raw materials pass through the filter unit; the filter module has inner and outer filter partitions and at least one elastic or soft sealing partition with compressibility, and a filter unit is surrounded between the inner and outer partitions; and an outlet pipe, which is an axial flow guide assembly, wherein the lower part of the outlet pipe is the outlet for the filtrate, and the upper part of the outlet pipe is located at the bottom center of the second flow channel, wherein the upper part of the outlet pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the filtrate is discharged.

[0052] As shown in Figures 10 to 12, according to the above embodiments of the present invention, a blood filtration method for leukocyte reduction is provided, which includes providing a flexible flat-plate leukocyte reduction filter, including a housing, a filter module disposed within the housing, the filter module having a first flow channel located at the center of the inner side of the filter module, a second flow channel located around the outer side of the filter module, and a sealing structure tightly connected to the filter module and the housing, thereby sealing the first flow channel; blood raw materials are uniformly diffused radially from the first flow channel to the second flow channel outside the filter module by pressure difference, thereby filtering the blood raw materials to produce filtrate, which flows into the bottom of the second flow channel.

[0053] As shown in Figures 5 to 9, according to an embodiment of the present invention, a flexible flat-plate leukocyte reduction filter with a radial flow field is provided, comprising: a housing and a filter module disposed within the housing, the filter module having a plurality of stacked filter units, a first flow channel and a second flow channel between the filter module and the housing, the first flow channel being located at the inner center of the filter module, and the second flow channel surrounding the outer periphery of the filter module, wherein blood raw material generates radial flow between the first flow channel and the second flow channel; and a separator column, the separator column... Located inside the filtration module, the first flow channel separates and encloses a blood raw material holding space at its upper part and a secondary filtrate holding space at its lower part. These spaces are situated inside the filtration module, while the second flow channel lies outside. Blood raw materials first flow radially outward from the blood raw material holding space to the filtration module for primary filtration, generating primary filtrate which then collects in the second flow channel. The primary filtrate then flows radially inward from the second flow channel. The fluid flows to the filtration module for a second filtration, producing secondary filtrate, which is then collected in the secondary filtrate receiving space. The feed pipe, an axial flow guide assembly, establishes the axial or central input / output path of the fluid within the filter and supports the filtration unit. The upper part of the feed pipe serves as the inlet for the blood raw material, located at the top center of the housing. The lower part of the feed pipe connects to the blood raw material receiving space, and the lower part of the feed pipe has multiple holes with varying opening densities based on the axial height to balance the blood raw material flow. The pressure generated when the filtration unit passes through it; the filtration module has inner and outer filtration partitions, and at least one elastic or soft sealing partition with compressibility, and a surrounding filtration unit is disposed between the inner and outer partitions; the discharge pipe is an axial flow guide assembly, the lower part of the discharge pipe is the outlet of the filtrate, and the upper part of the discharge pipe is located at the bottom center of the secondary filtrate containing space, wherein the upper part of the discharge pipe has multiple holes, and different opening densities are provided according to the axial height to balance the pressure generated when the filtrate is discharged.

[0054] As shown in Figures 5 to 9, according to the above embodiments of the present invention, a blood filtration method for leukocyte reduction includes providing a flexible flat-plate leukocyte reduction filter, comprising a housing and a filter module disposed within the housing. The filter module and the housing have a first flow channel located at the center of the inner side of the filter module, a second flow channel located around the outer side of the filter module, and a partition column located in the first flow channel inside the filter module, separating and sealing the upper part of the first flow channel as a blood raw material holding space and the lower part of the first flow channel as a secondary filtrate holding space. The blood raw material flows radially outward from the blood raw material holding space to the filter module for a first filtration, generating a primary filtrate which is collected in the second flow channel. The primary filtrate flows radially inward from the second flow channel to the filter module for a second filtration, generating a secondary filtrate which is collected in the secondary filtrate holding space. The blood raw material is introduced into the blood raw material holding space through an inlet pipe and the secondary filtrate is discharged through an outlet pipe located at the center of the bottom of the secondary filtrate holding space.

[0055] As shown in Figures 5 to 12, according to the above embodiments of the present invention, the outer shell of the present invention is made of a medical-grade flexible polymer material, which includes: polyvinyl chloride (PVC), ethylene vinyl acetate (EVA), and medical-grade polyurethane (PU). The advantage of the flexible shell design is that when the filter of the present invention is placed in a centrifuge for the blood component centrifugation preparation method, the shell can undergo slight deformation to conform to the geometry of the inner wall of the centrifuge cup, thereby significantly increasing the contact area with the centrifuge cup and allowing the centripetal pressure to be evenly distributed on the shell surface.

[0056] Furthermore, the above examples include sequential exemplary steps, but these steps need not be performed in the order shown. Performing these steps in different orders is within the scope of this invention. Within the spirit and scope of the embodiments of this invention, these steps may be added, substituted, changed in order, and / or omitted as appropriate.

[0057] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the scope of the invention. Any person skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A flexible flat-plate leukocyte reduction filter with radial flow field, characterized in that, It includes: Two outer shells, which are flat against each other; Two filter layers are flatly attached to each other and disposed between the inner sides of the two outer shells, wherein the two filter layers are joined with the edges of the two outer shells to form a joint; A first filter media accommodating space is formed between the inner sides of the two outer shells, the outer sides of the two filter layers, and the joint portion; and A filter layer separator is formed between the inner surfaces of the two filter layers. The inner surfaces of the two filter layers, the filter layer separator, and the junction form a blood raw material accommodating space and a second filter material accommodating space. Herein, the blood raw material diffuses radially from the inside to the outside of the blood raw material accommodating space to the inner surfaces of the two filter layers for the first time. At the same time, the pressure difference between the inner and outer sides of the two filter layers performs the first filtration and forms the first filter material, which is then introduced and collected in the first filter material accommodating space. The first filter material diffuses radially from the outside to the inside of the two filter layers for the second time. At the same time, the pressure difference between the inner and outer sides of the two filter layers performs the second filtration to form the second filter material, which is then introduced and collected in the second filter material accommodating space.

2. The flexible flat-plate leukocyte reduction filter with radial flow field according to claim 1, characterized in that, The blood raw material storage space and the second filter material storage space are located in the middle of the flexible flat plate leukocyte removal blood filter, and are sequentially divided into upper and lower positions by the filter layer separator column.

3. The flexible flat-plate leukocyte reduction filter with radial flow field according to claim 1, characterized in that, It also includes a feed tube having a first feed tube portion and a second feed tube portion. The first feed tube portion has a feed tube inlet, and the second feed tube portion has multiple feed tube outlets. The second feed tube portion passes through the connecting portion between the two filter layers and is connected to the blood raw material containing space, so that the blood raw material is introduced from above through the feed tube inlet and enters the blood raw material containing space through the multiple feed tube outlets.

4. The flexible flat-plate leukocyte reduction filter with radial flow field according to claim 1, characterized in that, It also includes a discharge pipe, which has a first discharge pipe portion and a second discharge pipe portion. The first discharge pipe portion has multiple discharge pipe inlets, and the second discharge pipe portion has a discharge pipe outlet. The first discharge pipe portion passes through the joint between the two filter layers and communicates with the second filter media receiving space. Thereby, the second filter media is guided from the second filter media receiving space to the multiple discharge pipe inlets of the first discharge pipe portion and discharged from below through the discharge pipe outlet.

5. A blood filtration method for leukopenia, characterized in that, It includes: A flexible flat-plate leukocyte reduction filter is provided, comprising a housing, a filter module disposed within the housing, wherein the filter module has a first flow channel located at the center of the inner side of the filter module, a second flow channel surrounding the outer periphery of the filter module, and a sealing structure that tightly connects and seals the filter module and the housing to form the first flow channel; and Blood raw materials are evenly diffused radially from the first flow channel to the second flow channel outside the filter module by pressure difference, thereby filtering the blood raw materials to produce filtrate, which flows to the bottom of the second flow channel.

6. The blood filtration method for leukopenia according to claim 5, characterized in that, The flexible flat-plate leukocyte reduction filter also includes: This filtration module has multiple stacked filtration units; The feed pipe is an axial flow guide assembly used to establish the axial or central input / output path of the fluid in the filter and the support of the filter unit. The upper part of the feed pipe is the inlet of the blood raw material, the lower part of the feed pipe is located in the first flow channel, and the lower part of the feed pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the blood raw material passes through the filter unit. The filter module has inner and outer filter compartments, at least one elastic or soft sealing compartment that is compressible, and a filter unit is disposed between the inner and outer compartments. as well as The discharge pipe is an axial flow guide assembly. The lower part of the discharge pipe is the outlet of the filtrate, and the upper part of the discharge pipe is located at the center of the bottom of the second flow channel. The upper part of the discharge pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the filtrate is discharged.

7. The blood filtration method for leukopenia according to claim 5, characterized in that, The filter module and the sealing structure separate the internal space of the housing into a central area and a peripheral area. The central area is located at the center of the internal space of the housing, and the peripheral area surrounds the central area in the internal space of the housing to form a concave space. The first flow channel is located in the central area, and the second flow channel is located in the peripheral area.

8. A flexible flat-plate leukocyte reduction filter with radial flow field, characterized in that, It includes: Two outer shells are flatly and sealed together to form a housing, and the edge portions of the two outer shells are joined together to form a housing joint. Two filter layers are flatly attached to each other and disposed between the inner sides of the two outer shells, wherein the two filter layers are joined with the edge portions of the two outer shells to form a joint; The filter layer junction is formed by the bottom edges of the two filter layers joining together. The blood raw material containing space is formed by the inner surfaces of the two filter layers, the filter layer joint, and the joint sealing. The filter media receiving space is formed by the inner sides of the two outer shells, the outer sides of the two filter layers, the filter layer joint, the outer shell joint and the joint. Blood raw material diffuses radially from the blood raw material receiving space to the two filter layers by the pressure difference between the inner and outer sides of the two filter layers to filter and form filter media. The filter media flows downward along the inner sidewall of the shell and is introduced and collected in the filter media receiving space.

9. The flexible flat-plate leukocyte reduction filter with radial flow field according to claim 8, characterized in that, The filter layer junction and the two filter layers divide the internal space of the housing into a central area and a peripheral area. The central area is located at the center of the internal space of the housing, and the peripheral area surrounds the central area in the internal space of the housing to form a concave space. The blood raw material accommodating space is located in the central area, and the filter material accommodating space is located in the peripheral area.

10. The flexible flat-plate leukocyte reduction filter with radial flow field according to claim 8, characterized in that, It also includes a feed pipe with a feed pipe inlet and a feed pipe outlet for introducing blood raw materials into the blood raw material receiving space, wherein the feed pipe passes through the joint from the middle position of the top of the housing and connects to the blood raw material receiving space.

11. The flexible flat-plate leukocyte reduction filter with radial flow field according to claim 8, characterized in that, It also includes a discharge pipe with a discharge pipe inlet and a discharge pipe outlet. The discharge pipe inlet passes through the middle of the bottom of the housing space, through the housing joint and communicates with the filter media receiving space, so that the filter media can be discharged from the filter media receiving space through the discharge pipe into the housing.

12. A blood filtration method for leukopenia, characterized in that, It includes: A flexible flat-plate leukocyte reduction filter is provided, comprising a housing and a filter module disposed within the housing. The filter module has a first flow channel located at the center of the inner side of the filter module, a second flow channel located around the outer side of the filter module, and a partition column located in the first flow channel inside the filter module. The upper part of the first flow channel is separated and closed as a blood raw material holding space, and the lower part of the first flow channel is a secondary filtrate holding space. Blood raw material flows radially outward from the blood raw material accommodating space to the filtration module for the first filtration and generates the primary filtrate, which is then collected in the second flow channel. as well as The primary filtrate flows radially inward from the second flow channel to the filtration module for a second filtration, generating secondary filtrate, which is then collected in the secondary filtrate holding space.

13. The blood filtration method for leukopenia according to claim 12, characterized in that, The flexible flat-plate leukocyte reduction filter also includes: This filtration module has multiple stacked filtration units; The feed pipe is used to introduce blood raw materials into the blood raw material receiving space. The feed pipe is an axial flow guide assembly used to establish the axial or central input / output path of the fluid in the filter and the support of the filter unit. The upper part of the feed pipe is located at the top center of the housing, the lower part of the feed pipe is located in the first flow channel, and the lower part of the feed pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the blood raw materials pass through the filter unit. The filter module has inner and outer filter layers, and at least one elastic or soft sealing layer that is compressible, with a surrounding filter unit disposed between the inner and outer filter layers; and The discharge pipe is used to discharge the secondary filtrate. The discharge pipe is an axial flow guide assembly. The lower part of the discharge pipe is the outlet of the filtrate, and the upper part of the discharge pipe is located at the center of the bottom of the second flow channel. The upper part of the discharge pipe has multiple holes with different opening densities according to the axial height to balance the pressure generated when the filtrate is discharged.

14. The blood filtration method for leukopenia according to claim 12, characterized in that, The blood raw material storage space and the secondary filtrate storage space are located in the middle of the flexible flat plate leukocyte removal blood filter, and are sequentially divided into upper and lower positions by the partition column.

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