Medical filter

Abstract

A medical filter (10) is provided with a housing (12), an inflow port (14), a filter medium (18), an outflow port (16), and a joining section (21). The joining section (21) joins portions that face each other inside the filter medium (18).

Description

Medical Filters

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to medical filters.

[0002] Japanese Patent Laid-Open Publication No. 7-67952 discloses a medical filter. The medical filter has a housing, an inlet port, an outlet port, and a filter material. The housing has an internal space. The inlet port and the outlet port are each fixed to the periphery of the housing. The filter material is fixed to the housing and disposed in the internal space of the housing. The filter material divides the internal space of the housing into an inlet region and an outlet region. Liquid (blood) flows into the inlet region through the inlet port. The filter material blocks the passage of specific components (white blood cells) of the liquid that flows into the inlet region. The liquid that passes through the filter material flows into the outlet region. The liquid that flows into the outlet region flows out of the housing through the outlet port.

[0003] Japanese Patent Application Publication No. 7-67952

[0004] When the filter medium is made of a soft material such as polyurethane, the pressure of the liquid flowing into the inlet region and passing through the filter medium causes the filter medium to deform. Specifically, the pressure of the liquid passing through the filter medium causes the filter medium to expand in the thickness direction. When the filter medium expands, the pore size of the filter medium increases, which may allow certain components to pass through the filter medium. As a result, the filtration performance of the filter medium may decrease.

[0005] The present invention aims to solve the above-mentioned problems.

[0006] (1) An aspect of the present invention is a medical filter comprising: a housing having an internal space; an inlet port fixed to the peripheral portion of the housing for allowing liquid to flow into the internal space from outside the housing; a filter material fixed to the housing and arranged in the internal space; and an outlet port fixed to the peripheral portion for allowing the liquid that has passed through the filter material to flow out to the outside, wherein the filter material is formed in a bag shape and the internal space is divided into an inlet region into which the liquid flows in through the inlet port and an outlet region from which the liquid that has passed through the filter material flows out to the outside through the outlet port, so that the interior of the filter material is formed as the inlet region, and the medical filter comprises a joint that joins parts of the filter material that face each other on the inside.

[0007] This configuration simply and easily prevents the filter medium from being deformed by the pressure of the liquid flowing into the inflow area and passing through the filter medium, thereby preventing a decrease in the filtering performance of the filter medium due to deformation of the filter medium.

[0008] (2) In the medical filter described in (1) above, the filter material has a filtering function portion surrounded by the outflow region within the internal space, and a first end portion, which is one end of the filter material, and the inlet port are fixed to the peripheral portion, the direction from the first end portion toward the second end portion, which is the other end of the filter material, is defined as the length direction of the filter material, and the direction perpendicular to the thickness direction and the length direction of the filter material is defined as the width direction of the filter material, and the joint portion may be located in a region where, when viewed from the thickness direction, the central region when the filtering function portion is divided into thirds in the length direction overlaps with the central region when the filtering function portion is divided into thirds in the width direction.

[0009] This configuration effectively prevents the filter medium from being deformed by the pressure of the liquid passing through the filter medium.

[0010] (3) In the medical filter described in (2) above, the joint portion may be located at the center of the filtering function portion when viewed in the thickness direction.

[0011] This configuration can efficiently prevent the filter medium from being deformed by the pressure of the liquid passing through the filter medium.

[0012] (4) In the medical filter described in any one of (1) to (3) above, the joint may join a wall portion on one side of the housing in the thickness direction of the filter material, the filter material, and a wall portion on the other side of the housing in the thickness direction.

[0013] This configuration can more effectively prevent the filter medium from being deformed by the pressure of the liquid passing through the filter medium.

[0014] (5) In the medical filter described in any one of (1) to (4) above, the medical filter may further include a reinforcing material through which the liquid that has passed through the filter material can pass and which suppresses deformation of the filter material due to the pressure of the liquid passing through the filter material, and the reinforcing material may have a parallel portion and a tapered portion connected to the parallel portion when the liquid is passing through.

[0015] This configuration more effectively prevents the filter medium from being deformed by the pressure of the liquid flowing into the inflow region and passing through the filter medium.

[0016] (6) In the medical filter described in (5) above, the reinforcing material may have lower extensibility than the filter material and may be formed in a bag shape so as to cover the filter material in the outflow region.

[0017] According to this configuration, by covering the filter medium with the reinforcing material, it is possible to effectively prevent the filter medium from being deformed by the pressure of the liquid passing through the filter medium.

[0018] (7) In the medical filter described in (6) above, the base end of the filtering material, the inlet port, and the base end of the reinforcing material may be integrally fixed to the peripheral edge of the housing.

[0019] This configuration allows the filter medium, inlet port, and reinforcing material to be easily secured inside the housing.

[0020] (8) In the medical filter described in (6) or (7) above, the joint may join a wall portion on one side of the reinforcing material in the thickness direction of the filter material, the filter material, and a wall portion on the other side of the reinforcing material in the thickness direction.

[0021] This configuration more effectively prevents the filter medium from being deformed in the outflow region by the pressure of the liquid passing through the filter medium.

[0022] (9) In the medical filter described in (6) or (7) above, the joint may join a wall portion on one side of the housing in the thickness direction of the filter material, a wall portion on one side of the reinforcing material in the thickness direction, the filter material, a wall portion on the other side of the reinforcing material in the thickness direction, and a wall portion on the other side of the housing in the thickness direction.

[0023] This configuration can more effectively prevent the filter medium from being deformed by the pressure of the liquid passing through the filter medium.

[0024] (10) In the medical filter described in any one of (6) to (9) above, the parallel portion may be parallel to the axial direction of the inlet port, and the tapered portion may be inclined with respect to the axial direction and connected to the parallel portion so as to surround the parallel portion.

[0025] With this configuration, when liquid flows into the inlet area, the pressure of the liquid can effectively prevent the filter material from expanding in a direction perpendicular to the axial direction of the inlet port (in the thickness and width directions of the housing).

[0026] (11) In the medical filter described in any one of (6) to (10) above, the filter material may be a porous material that allows the liquid to pass through, and the reinforcing material may be a porous material having a pore size larger than the pore size of the filter material.

[0027] With this configuration, it is possible to prevent the liquid that has passed through the filter material from being blocked by the reinforcing material.

[0028] (12) In the medical filter described in (11) above, the reinforcing material may be a nonwoven fabric.

[0029] This configuration makes it easy to cover the filter material with the reinforcing material in the outflow area.

[0030] (13) In the medical filter according to any one of (1) to (12) above, the joint may be formed by fusing together portions of the filter medium that face each other inside the filter medium.

[0031] According to this configuration, the inner portions of the filter medium facing each other can be simply and easily joined together.

[0032] According to the present invention, it is possible to simply and easily prevent the filter medium from being deformed by the pressure of the liquid flowing into the inflow area and passing through the filter medium, thereby preventing a decrease in the filtering performance of the filter medium due to deformation of the filter medium.

[0033] FIG. 1 is a front view of a medical filter according to a first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIGS. 4A and 4B are partial cross-sectional views showing other configuration examples of a filter medium. FIG. 5 is a cross-sectional view of a medical filter according to a second embodiment taken along line V-V in FIG. 1. FIG. 6 is a cross-sectional view of a medical filter according to a second embodiment taken along line VI-VI in FIG. 1. FIG. 7 is a front view of a medical filter according to a third embodiment. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. FIG. 9 is a front view of a medical filter according to a fourth embodiment. FIG. 10 is a front view of a medical filter according to a fifth embodiment. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 10. FIG. 12 is a front view of a medical filter according to a sixth embodiment. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 12. Fig. 15 is a cross-sectional view of the medical filter according to the seventh embodiment taken along line XV-XV in Fig. 12. Fig. 16 is a cross-sectional view of the medical filter according to the seventh embodiment taken along line XVI-XVI in Fig. 12. Fig. 17 is a front view of the medical filter according to the seventh embodiment with liquid flowing into the inflow region. Fig. 18 is a cross-sectional view taken along line XVIII-XVIII in Fig. 17. Fig. 19 is a cross-sectional view of the medical filter. Fig. 20 is a cross-sectional view of the medical filter. Fig. 21 is a cross-sectional view taken along line XXI-XXI in Fig. 17. Fig. 22 is a cross-sectional view of the medical filter according to the eighth embodiment taken along line XXII-XXII in Fig. 12. Fig. 23 is a front view of the medical filter according to the ninth embodiment. Fig. 24 is a front view of the medical filter according to the tenth embodiment. Fig. 25 is a front view of the medical filter according to the eleventh embodiment.

[0034] A medical filter 10 according to a first embodiment will be described with reference to FIGS. 1 to 4B. The medical filter 10 is a filter for filtering a liquid 49 (see FIGS. 18 and 21). The medical filter 10 is a filter for preventing the passage of predetermined components in the liquid 49. The medical filter 10 may be a filter for preventing the passage of predetermined components in blood (e.g., white blood cells). Note that FIGS. 1 to 4B show the medical filter 10 in an initial state, when no liquid 49 is being supplied.

[0035] As shown in FIGS. 1-3, the medical filter 10 includes a housing 12, an inlet port 14, an outlet port 16, a filter media 18, and a joint 21.

[0036] The housing 12 is a rectangular bag. The housing 12 has a first sheet portion 20 and a second sheet portion 22. The first sheet portion 20 and the second sheet portion 22 are two separate flexible sheets. The first sheet portion 20 and the second sheet portion 22 are transparent sheets. The first sheet portion 20 and the second sheet portion 22 are rectangular sheets of the same size and thickness. The first sheet portion 20 and the second sheet portion 22 are made of a synthetic resin. Specifically, examples of materials that can be used for the first sheet portion 20 and the second sheet portion 22 include thermoplastic elastomers such as soft vinyl chloride, polyurethane, ethylene-vinyl acetate copolymer, hydrogenated styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer or hydrogenated products thereof, and mixtures of thermoplastic elastomers with softeners such as polyolefins and ethylene-ethyl acrylate.

[0037] The housing 12 is formed into a bag shape by overlapping the first sheet portion 20 and the second sheet portion 22 and fusing the outer edge 24 of the first sheet portion 20 and the outer edge 26 of the second sheet portion 22. The first sheet portion 20 and the second sheet portion 22 may be fused together by external heat fusing using heat sealing. Alternatively, the first sheet portion 20 and the second sheet portion 22 may be fused together by internal heat fusing using a high-frequency welder, an ultrasonic welder, or the like. In the following description, "fusing" includes the above-mentioned external heat fusing and internal fusing.

[0038] The fused outer edge portions 24, 26 of the first sheet portion 20 and the second sheet portion 22 form a peripheral edge portion 28 of the housing 12. Furthermore, by fusing the outer edge portions 24, 26 of the first sheet portion 20 and the second sheet portion 22, an internal space 30 is formed inside the housing 12. In the following description, the fused portion of the housing 12 will be referred to as a fused region 32. In Figure 1, the fused region 32 is shown by a two-dot chain line.

[0039] Alternatively, the housing 12 may be formed by folding a single flexible sheet, overlapping the sheets, and fusing the outer edges of the flexible sheet. In this case, one portion of the folded flexible sheet becomes the first sheet portion 20, and the other portion becomes the second sheet portion 22.

[0040] As shown in FIGS. 1 and 2 , the inflow port 14 is a tubular member. The inflow port 14 is provided at a first end 31, which is one end of the housing 12. Specifically, the inflow port 14 penetrates the first end 31 of the peripheral edge 28 of the housing 12 and is inserted into the internal space 30 of the housing 12. The inflow port 14 is fixed to the peripheral edge 28 of the housing 12 by being fused to the first end 31 of the housing 12. The inflow port 14 is made of, for example, a synthetic resin. The inflow port 14 allows a liquid 49, such as blood (see FIGS. 18 and 21 ), to flow from the outside of the housing 12 into the internal space 30 of the housing 12.

[0041] The outlet port 16 is a cylindrical member of the same size and shape as the inlet port 14. The outlet port 16 is provided at the second end 33, which is the other end of the housing 12. Specifically, the outlet port 16 penetrates the second end 33 of the peripheral edge 28 of the housing 12 and is inserted into the internal space 30 of the housing 12. The outlet port 16 is fixed to the peripheral edge 28 of the housing 12 by being fused to the second end 33 of the housing 12. The constituent material of the outlet port 16 is the same as the constituent material of the inlet port 14. The outlet port 16 allows the liquid 49 in the internal space 30 of the housing 12 to flow out of the housing 12.

[0042] The inlet port 14 and the outlet port 16 are fixed to a peripheral edge 28 of the housing 12 while facing each other. That is, the inlet port 14 and the outlet port 16 are fixed coaxially to the housing 12. The inlet port 14 and the outlet port 16 are arranged on a central axis 34 of the inlet port 14.

[0043] The filter medium 18 is disposed in the internal space 30 of the housing 12. The filter medium 18 is formed in a rectangular shape when viewed from the front in FIG. 1 . The filter medium 18 is formed in a bag shape when viewed in cross section in FIGS. 2 and 3 . The filter medium 18 is fused to the housing 12, thereby being fixed thereto. As shown in FIG. 1 , the filter medium 18 is fixed to the housing 12 coaxially with the central axis 34. A base end 36 (one end, first end) of the filter medium 18 faces the inlet port 14. A tip end 38 (other end, second end) of the filter medium 18 faces the outlet port 16.

[0044] The direction from the base end 36 to the tip end 38 of the filter medium 18 is defined as the length direction of the filter medium 18. In the following description, the length direction of the filter medium 18 may be referred to as direction A. Because the filter medium 18 is disposed within the housing 12 along the central axis 34, direction A is also the axial direction of the inlet port 14.

[0045] The width direction of the filter medium 18 is defined as the direction perpendicular to the direction A (the left-right direction in FIGS. 1 and 3). In the following description, the width direction of the filter medium 18 may be referred to as the direction B.

[0046] The thickness direction of the filter medium 18 is defined as the direction perpendicular to the A and B directions (the left-right direction in FIG. 2 and the up-down direction in FIG. 3). In the following description, the thickness direction of the filter medium 18 may be referred to as the C direction.

[0047] The direction A is also the length direction of the housing 12. The direction B is also the width direction of the housing 12. The direction C is also the thickness direction of the housing 12.

[0048] The filter medium 18 is a porous body made of synthetic resin or synthetic fiber. Examples of materials for the filter medium 18 include polyester, polyamide, polypropylene, polyethylene, polyurethane, polyvinyl chloride, acrylonitrile, and styrene-based elastomers. The pore size and thickness of the porous body can be appropriately selected depending on the blood component to be separated and removed from blood. For example, when the blood component to be separated and removed from blood is white blood cells, a porous body with an average pore size of 3 μm to 20 μm is preferred.

[0049] The filter medium 18 is formed by folding one rectangular flexible sheet 35 made of the above-mentioned constituent materials into a U-shape and fusing the outer edges of the folded flexible sheet 35. Therefore, the filter medium 18 is formed into a bag shape by fusing the outer edges of the one flexible sheet 35. Alternatively, the filter medium 18 may be formed into a bag shape by overlapping two flexible sheets 35 made of the above-mentioned constituent materials and fusing the outer edges of the two flexible sheets 35.

[0050] The filter media 18 may be formed as shown in Figures 4A and 4B.

[0051] The filter medium 18 shown in FIG. 4A is formed by stacking a plurality of rectangular flexible sheets 35, folding them into a U-shape, and fusing the outer edges of the folded flexible sheets 35 together.

[0052] The filter medium 18 shown in Figure 4B is formed into a bag shape by stacking multiple rectangular flexible sheets 35 and fusing the outer edges of the multiple flexible sheets 35. Specifically, one sheet body 39 made up of multiple overlapping flexible sheets 35 and another sheet body 39 made up of multiple overlapping flexible sheets 35 are prepared. The outer edge of one sheet body 39 is fused to the outer edge of the other sheet body 39, forming the filter medium 18 into a bag shape. In this case, the outer edge of one sheet body 39 is the outer edge of the multiple flexible sheets 35 that make up the one sheet body 39. The outer edge of the other sheet body 39 is the outer edge of the multiple flexible sheets 35 that make up the other sheet body 39.

[0053] 1 and 2, the inlet port 14 is inserted into the base end 36 of the bag-shaped filter medium 18. That is, the inlet port 14 is in communication with the interior of the filter medium 18. The housing 12, the base end 36 of the filter medium 18, and the inlet port 14 are fused together. As a result, the base end 36 of the filter medium 18 and the inlet port 14 are fixed to the housing 12 as a unit.

[0054] The filter medium 18 divides the interior space 30 of the housing 12 into an inlet region 40 and an outlet region 42. Specifically, the inlet region 40 is the space inside the filter medium 18. The inlet region 40 communicates with the outside of the housing 12 via the inlet port 14. A liquid 49 (see FIGS. 18 and 21 ) flows into the inlet region 40 via the inlet port 14.

[0055] The filter 18 prevents passage of predetermined components (e.g., white blood cells in blood) in the liquid 49 that has flowed into the inflow region 40. The filter 18 allows passage of components of the liquid 49 other than the predetermined components.

[0056] The outflow region 42 is a space outside the filter medium 18 within the internal space 30 of the housing 12. The outflow region 42 is in communication with the outlet port 16. Liquid 49 that has passed through the filter medium 18 flows into the outflow region 42. The liquid 49 that has flowed into the outflow region 42 flows out of the housing 12 via the outlet port 16.

[0057] When liquid 49 flows into inflow region 40, filter medium 18 is subjected to the pressure of liquid 49. In order to suppress deformation of filter medium 18 due to the pressure of liquid 49, joint portion 21 fuses portions facing each other inside filter medium 18, thereby joining the portions facing each other.

[0058] Specifically, the filter medium 18 has a filtering function section 41. The filtering function section 41 is a portion of the internal space 30 that is surrounded by the outflow region 42. The filtering function section 41 is a portion of the filter medium 18 that filters the liquid 49 that has flowed into the inflow region 40. The filtering function section 41 is a portion of the filter medium 18 that is not fused to the housing 12. In other words, the filtering function section 41 is a portion of the filter medium 18 other than the portion that is fused to the housing 12. In the first embodiment, the base end 36 of the filter medium 18 is fused to the housing 12. Therefore, the base end 36 of the filter medium 18 cannot filter the liquid 49. The base end 36 of the filter medium 18 is not included in the filtering function section 41.

[0059] As shown in Fig. 1, the joint 21 is located in a central region 45 of the filtration function unit 41 when viewed in the thickness direction of the filter medium 18 (direction C in Figs. 2 and 3). More specifically, when viewed in the thickness direction of the filter medium 18, the filtration function unit 41 can be virtually divided into nine regions 43 by dividing the filtration function unit 41 into three equal parts in the length direction (direction A) and three equal parts in the width direction (direction B). In Fig. 1, the nine virtual regions 43 in the filtration function unit 41 are illustrated by two-dot chain lines. The region 43 where the central region 43 in the A direction and the central region 43 in the B direction overlap is the central region (central region 45) of the nine regions 43.

[0060] As shown in Fig. 2, the joint 21 may be formed by sandwiching the filter medium 18 from both sides in the C direction (left-right direction). As a result, the filter medium 18 has a symmetrical shape in the C direction of Fig. 2. Alternatively, the joint 21 may be formed by fusing one side of the filter medium 18 in the C direction (for example, the right-side region of the filter medium 18 in the C direction) to the other side of the filter medium 18 (the left-side region of the filter medium 18 in the C direction). As a result, the right side of the filter medium 18 has a shape with a flat surface. Furthermore, the left side of the filter medium 18 is pressed from the right side of the filter medium 18, forming an E-shape.

[0061] It is preferable that the size of the joint 21 be as small as possible. This is because if the size of the joint 21 increases, the effective filtration area of ​​the filter medium 18 decreases. In the front view of Fig. 1, the joint 21 is at least smaller than the region 43. More preferably, the joint 21 is smaller than 5% of the region 43. In Fig. 1, the size of the joint 21 is approximately 5.4% of the size of the region 43.

[0062] A central portion 47 of the filtration function portion 41 is located in the central region 45. The central portion 47 is a portion that is narrower than the central region 45. The central portion 47 is located at the center or center of gravity of the filtration function portion 41.

[0063] The joint 21 is located in a central region 45 of the filtering function part 41 when viewed from the thickness direction of the filter medium 18. Fig. 1 illustrates a case where the joint 21 is located in a center part 47 when viewed from the thickness direction.

[0064] The shape of the joint 21 may be any shape that does not impede the flow of the liquid 49 in the filter medium 18 and does not stagnate the flow of the liquid 49 within the filter medium 18. In FIG. 1 , the joint 21 is formed in a circular shape when viewed in the thickness direction of the filter medium 18. The shape of the joint 21 is not limited to a circular shape. The shape of the joint 21 may be a dot, a semicircle, a triangle, or other polygonal shape. The external shape of the joint 21 may also be a convex shape, a semi-arc shape, or a dashed or wavy line extending in any direction (e.g., direction A). The joint 21 preferably has a shape that extends convexly toward the inflow tube 14. By forming the joint 21 in a convex shape toward the inflow tube 14, blood can flow more easily toward the outflow port 16, preventing stagnation of the blood flow.

[0065] The joint 21 joins the inner wall portion on one side of the filter medium 18 in the thickness direction to the inner wall portion on the other side in the thickness direction of the filter medium 18. Specifically, the joint 21 fuses the central region 45 or the central portion 47 of the inner wall portion on one side to the central region 45 or the central portion 47 of the inner wall portion on the other side.

[0066] Note that, as long as portions facing each other inside the filter medium 18 are joined, the joints 21 may be provided in portions other than the center portion 47 in the central region 45. Alternatively, the joints 21 may be provided in regions 43 other than the central region 45. Furthermore, a plurality of joints 21 may be provided for the filter medium 18. Specifically, the plurality of joints 21 are linearly arranged in one direction at intervals in the filtration function section 41. Alternatively, the plurality of joints 21 are arranged in a dice pattern in the filtration function section 41. More specifically, when the plurality of joints 21 are arranged in a dice pattern, the joints 21 are provided so as to be distributed in each of the nine regions 43. Alternatively, the joints 21 are provided so as to be distributed in at least two of the nine regions 43. More preferably, the joints 21 are provided at the center of gravity of each of the nine regions 43. For example, if four joints 21 are provided on the filter medium 18, a joint 21 is disposed in each of the four of the nine regions 43 (four regions 43: upper right, lower right, upper left, and lower left) that face the four corners of the central region 45. By providing a plurality of joints 21 in this manner, each of the plurality of joints 21 can join portions that face each other inside the filter medium 18. Furthermore, the plurality of joints 21 can hinder the flow of the liquid 49 within the inflow region 40, preventing the liquid 49 from stagnating.

[0067] Furthermore, the joint 21 may join the inner wall portion on one side of the filter medium 18 to the inner wall portion on the other side by a method other than fusion. The joint 21 may also use an adhesive to bond the inner wall portion on one side of the filter medium 18 to the inner wall portion on the other side. The joint 21 may also use a bolt and a nut to join the inner wall portion on one side of the filter medium 18 to the inner wall portion on the other side. The joint 21 may also use a rivet to join the inner wall portion on one side of the filter medium 18 to the inner wall portion on the other side. Note that when a bolt and a nut or a rivet is used, the bolt, the nut, and the rivet need to be resistant to the liquid 49.

[0068] The fused region 32 includes a peripheral fused region 50 and a filter media fused region 52 .

[0069] The peripheral fused region 50 is a fused portion between the outer edge 24 of the first sheet portion 20 and the outer edge 26 of the second sheet portion 22 at the peripheral edge 28 of the housing 12. In the peripheral fused region 50, the outer edge 24 of the first sheet portion 20 and the outer edge 26 of the second sheet portion 22 are directly fused together.

[0070] The peripheral fused region 50 is integrally fused to the inlet port 14 and outlet port 16 .

[0071] The opening of the inlet port 14 on the outlet port 16 side (the opening communicating with the inlet region 40) is located at the filter medium fused region 52. Alternatively, the opening of the inlet port 14 on the outlet port 16 side may be located closer to the outlet port 16 than the filter medium fused region 52.

[0072] The filter medium fused region 52 is formed on the inner side in the width direction of the housing 12 than the peripheral fused region 50. The filter medium fused region 52 is a fused portion of the housing 12 with the filter medium 18. The filter medium fused region 52 extends along the B direction.

[0073] As shown in Fig. 1 , the filter medium fused region 52 is connected to the peripheral fused region 50. Specifically, both ends of the filter medium fused region 52 in the width direction and the base end of the filter medium fused region 52 in the axial direction are connected to the peripheral fused region 50. The filter medium fused region 52 is integrally fused to the base end 36 of the filter medium 18 and the inlet port 14. Although Fig. 2 shows a schematic diagram, strictly speaking, in the filter medium fused region 52, a portion of the housing 12 (the first sheet portion 20 and the second sheet portion 22) is impregnated with the filter medium 18. In the filter medium fused region 52, the outer peripheral surface of the inlet port 14 and the outer peripheral surface of the reinforcing material 19 are surrounded by the filter medium 18 and the housing 12. Therefore, in the filter medium fused region 52, at the location where the inlet port 14 is located, a portion of the housing 12 is impregnated with the filter medium 18, thereby integrally fusion-bonding the housing 12, the filter medium 18, and the inlet port 14. In the filter medium fused region 52, at a location other than the location where the inlet port 14 is located, a portion of the housing 12 is impregnated with the filter medium 18, thereby integrally fusion-bonding the first sheet portion 20, the filter medium 18, and the second sheet portion 22.

[0074] 1 and 3, the width L3 of the outflow region 42 in direction B is greater than the width L2 of the filter medium 18 in direction B (L3>L2). The outflow region 42 extends further toward the outflow port 16 than the tip 38 of the filter medium 18.

[0075] The medical filter 10 according to the first embodiment is used as follows.

[0076] Liquid 49, such as blood, is pumped from outside the housing 12 through the inlet port 14 and flows into the inlet region 40. The filter medium 18 blocks specific components, such as white blood cells, from passing through the liquid 49, while allowing components other than the specific components to pass through. After passing through the filter medium 18, the liquid 49 flows into the outlet region 42. After flowing into the outlet region 42, the liquid 49 flows out of the housing 12 through the outlet port 16.

[0077] At this time, the joints 21 join the portions facing each other inside the filter medium 18. Therefore, when the liquid 49 passes through the filter medium 18, the filter medium 18 can be prevented from being deformed by the pressure of the liquid 49. In other words, the filter medium 18 can be prevented from expanding in the C direction by the pressure of the liquid 49.

[0078] The first embodiment has the following advantages.

[0079] If the joint 21 is not provided, when the liquid 49 that has flowed into the inflow region 40 passes through the filter medium 18, the filter medium 18 may be deformed by the pressure of the liquid 49. Specifically, the filter medium 18 may expand in the thickness direction (direction C) of the filter medium 18 due to the pressure of the liquid 49 passing through the filter medium 18. The expansion of the filter medium 18 may increase the pore size of the porous body that constitutes the filter medium 18, which may reduce the filtering performance of the filter medium 18.

[0080] 1 to 4B, in the first embodiment, the joints 21 join the opposing portions of the inside of the filter medium 18. This makes it possible to simply and easily prevent the filter medium 18 from being deformed by the pressure of the liquid 49 that flows into the inflow region 40 and passes through the filter medium 18. As a result, it is possible to prevent a decrease in the filtering performance of the filter medium 18 due to deformation of the filter medium 18.

[0081] The filtration function section 41 of the filter medium 18 is surrounded by an outflow region 42 within the internal space 30. As shown in Fig. 1, when viewed from the thickness direction (direction C) of the filter medium 18, the joint 21 is located in a region 43 (central region 45) where the central region 43 when the filtration function section 41 is divided into three equal parts in the length direction (direction A) of the filter medium 18 overlaps with the central region 43 when the filtration function section 41 is divided into three equal parts in the width direction (direction B) of the filter medium 18. This effectively prevents the filter medium 18 from being deformed by the pressure of the liquid 49 passing through the filter medium 18.

[0082] When viewed from the C direction, the joint 21 is located at the center 47 of the filtration function part 41. This makes it possible to efficiently prevent the filter medium 18 from being deformed by the pressure of the liquid 49 passing through the filter medium 18.

[0083] The joints 21 fuse together the mutually facing portions inside the filter medium 18. This allows the mutually facing portions inside the filter medium 18 to be joined simply and easily.

[0084] A medical filter 60 according to a second embodiment will be described with reference to Figures 5 and 6. In the medical filter 60 according to the second embodiment, the same components as those in the medical filter 10 according to the first embodiment (see Figures 1 to 4B) are designated by the same reference numerals, and detailed description thereof will be omitted.

[0085] In the medical filter 60 according to the second embodiment, the joint 21 joins one wall of the housing 12 in the thickness direction (direction C) of the filter medium 18, the filter medium 18, and the other wall of the housing 12 in the direction C. Specifically, the joint 21 joins the inner wall of the first sheet portion 20, which is one wall of the housing 12, the central region 45 or center portion 47 of the filtering function portion 41, and the inner wall of the second sheet portion 22, which is the other wall of the housing 12. In this case, the joint 21 integrally fuses the inner wall of the first sheet portion 20, the central region 45 or center portion 47 of the filtering function portion 41, and the inner wall of the second sheet portion 22. Although schematically illustrated in FIGS. 5 and 6 , strictly speaking, at the joint 21, a portion of the housing 12 (the first sheet portion 20 and the second sheet portion 22) is impregnated with the filtering function portion 41. By impregnating a portion of the housing 12 with the filtering function unit 41, the housing 12 and the filtering function unit 41 are integrally fused at the joint 21. Note that the joint 21 may join one wall portion or the other wall portion of the housing 12 to the central region 45 or the central portion 47 of the filtering function unit 41.

[0086] The second embodiment also achieves the same effects as the first embodiment (see FIGS. 1 to 4B). In addition, in the second embodiment, the joint 21 joins the housing 12 and the filter medium 18, which more effectively prevents the filter medium 18 from being deformed by the pressure of the liquid 49 (see FIGS. 18 and 21) passing through the filter medium 18.

[0087] A medical filter 80 according to a third embodiment will be described with reference to FIGS.

[0088] In the third embodiment, the housing 12 further includes a non-fused region 44 and a window 46 .

[0089] The non-fused region 44 is a space formed inside the housing 12. The non-fused region 44 is a space separate from the internal space 30 of the housing 12. The non-fused region 44 is a spatial region that is not fused. The non-fused region 44 is surrounded by the fused region 32.

[0090] In the third embodiment, only both ends of the filter medium fused region 52 in direction B are connected to the peripheral fused region 50. In the third embodiment, the filter medium fused region 52 divides the interior of the housing 12 into the internal space 30 and the non-fused region 44. Specifically, the filter medium fused region 52 divides the non-fused region 44 from the outflow region 42 of the internal space 30.

[0091] The non-fused region 44 is formed between the filter media fused region 52 and the fused portion of the peripheral fused region 50 to the inlet port 14. The proximal end 54 of the filter media 18 is located in the non-fused region 44. Specifically, the proximal end 54 of the filter media 18 is located beyond the filter media fused region 52 and in the non-fused region 44.

[0092] Specifically, inlet port 14 is integrally fused to housing 12, sandwiched between peripheral fused region 50 and filter media fused region 52. More specifically, the portion of inlet port 14 located in non-fused region 44 is fused only to proximal end 54 of filter media 18. The portion of inlet port 14 located in non-fused region 44 is not fused to housing 12.

[0093] The non-fused region 44 extends along direction B. A width L1, which is the dimension of the non-fused region 44 in the width direction, is greater than a width L2 (L1>L2).

[0094] The window portion 46 is a part of the housing 12. The window portion 46 is a part of the first sheet portion 20 and the second sheet portion 22 that constitute the housing 12. The window portion 46 is a window portion for visually observing the non-fused region 44 from outside the housing 12. The window portion 46 is provided in the housing 12 so as to face the non-fused region 44. The window portion 46 is provided in the housing 12 between the non-fused region 44 and the peripheral fused region 50 so as to face the non-fused region 44. Therefore, in the front view of FIG. 7 , the size of the window portion 46 is the same as the size of the non-fused region 44. Therefore, the user can view the base end 54 of the filter medium 18 located in the non-fused region 44 through the window portion 46. As shown in FIG. 8 , the window portion 46 is provided in each of the first sheet portion 20 and the second sheet portion 22 so as to face the non-fused region 44.

[0095] The window portion 46 may be formed in at least one of the first sheet portion 20 and the second sheet portion 22 .

[0096] In the medical filter 80 according to the third embodiment, when the filter medium 18 filters a liquid 49 such as blood (see FIGS. 18 and 21 ), the liquid 49 may pass through portions of the fused region 32 where the fusion bonding strength is low. Such fusion abnormalities are likely to occur at the fusion points between the filter medium fused region 52 and the filter medium 18, and at the fusion points between the filter medium fused region 52, the base end 36 of the filter medium 18, and the inflow port 14. That is, the fusion bonding strength at the fusion points between the filter medium fused region 52 and the filter medium 18 is lower than that at the peripheral fused region 50. Furthermore, because three components, the filter medium fused region 52, the filter medium 18, and the inflow port 14, are fused together, the fusion bonding strength is likely to be lower than that at the peripheral fused region 50.

[0097] Therefore, if the above-described fusion abnormality occurs, the liquid 49 passes through the fused region 52 of the filter medium and flows into the unfused region 44. By visually checking the unfused region 44 through the window 46, the user can confirm whether the liquid 49 has flowed into the unfused region 44. If the user confirms that the liquid 49 has flowed into the unfused region 44, the user can easily recognize that an abnormality has occurred in the medical filter 80.

[0098] The third embodiment also provides the same effects as the first embodiment (see FIGS. 1 to 4B). Furthermore, the third embodiment also provides the following effects.

[0099] 7 and 8, if a liquid 49 (see FIGS. 18 and 21) is introduced into the internal space 30 of the housing 12 and the liquid 49 flows into the non-fused region 44, a fusion abnormality has occurred inside the medical filter 80. Therefore, by visually checking the inflow of the liquid 49 into the non-fused region 44 from outside the housing 12 through the window 46, an abnormality in the medical filter 80 can be detected early. Furthermore, by detecting an abnormality in the medical filter 80 early, loss of the liquid 49 can be reduced, and leakage of the liquid 49 to the outside of the medical filter 80 can be suppressed.

[0100] Because the fused filter region 52 is fused to the filter medium 18, the bonding strength due to fusion tends to be weaker than that of the peripheral fused region 50, which is the fused portion between the first sheet portion 20 and the second sheet portion 22. If a fusion abnormality occurs in the fused filter region 52, the liquid 49 will flow into the non-fused region 44. This is effective in early detection of abnormalities in the medical filter 80.

[0101] Because the housing 12, the filter medium 18, and the inlet port 14 are fused together, the fused area between the filter medium fused region 52, the base end 36 of the filter medium 18, and the inlet port 14 is likely to have a lower fusion bonding strength than the peripheral fused region 50. If a fusion defect occurs at the fused area, liquid 49 will flow into the unfused region 44 via the base end 54 of the filter medium 18. The base end 54 of the filter medium 18 is located in the unfused region 44 beyond the filter medium fused region 52. The window 46 faces the unfused region 44. This allows the user to visually check the base end 54 of the filter medium 18 located in the unfused region 44 through the window 46. The user can also easily check through the window 46 whether liquid 49 is flowing into the unfused region 44. This is effective for early detection of abnormalities in the medical filter 80.

[0102] The non-fused region 44 extends along direction B, and the width L1 of the non-fused region 44 in direction B is greater than the width L2 of the filter medium 18 in direction B (L1>L2). This allows the window 46 facing the non-fused region 44 to be larger. As a result, the non-fused region 44 can be easily seen through the window 46 from outside the housing 12.

[0103] The width L3 of the outflow region 42 in the direction B is greater than the width L2 of the filter medium 18 in the direction B (L3>L2). The fused filter region 52 separates the outflow region 42 from the non-fused region 44. If a fusion defect occurs in the fused filter region 52, the liquid 49 will flow from the outflow region 42 into the non-fused region 44. This is more effective in early detection of abnormalities in the medical filter 80.

[0104] A medical filter 85 according to a fourth embodiment will be described with reference to FIG.

[0105] In the medical filter 85 according to the fourth embodiment, the filter medium fused region 52 is integrally fused to the base end 36 and two side edge portions 62 of the filter medium 18, and to the inflow port 14. Therefore, the filter medium fused region 52 is formed in a U-shape. The filter medium fused region 52 may also be integrally fused to at least one of the two side edge portions 62 of the filter medium 18, the base end 36 of the filter medium 18, and the inflow port 14.

[0106] The fourth embodiment also provides the same effects as the first and third embodiments.

[0107] A medical filter 90 according to a fifth embodiment will be described with reference to FIGS.

[0108] In the medical filter 90 according to the fifth embodiment, the filter medium fused region 52 is integrally fused to two side edge portions 62 between the proximal end 36 and distal end 38 of the filter medium 18, the proximal end 36 of the filter medium 18, and the inflow port 14. Therefore, as shown in FIG. 10 , the filter medium fused region 52 is formed in a U-shape. Therefore, in the fifth embodiment, the two side edge portions 62 of the filter medium 18 cannot filter the liquid 49 (see FIGS. 18 and 21 ). In the fifth embodiment, the filtering function portion 41 is the portion of the filter medium 18 other than the proximal end 36 and the two side edge portions 62. The proximal end 36 and the two side edge portions 62 are not included in the filtering function portion 41. The filter medium fused region 52 may also be integrally fused to at least one of the two side edge portions 62 of the filter medium 18, the proximal end 36 of the filter medium 18, and the inflow port 14.

[0109] In the fifth embodiment, the non-fused region 44 is formed in a U-shape between the filter medium fused region 52 and the peripheral fused region 50. The non-fused region 44 has a widthwise portion 64 and two axial portions 66. The widthwise portion 64 is formed to face the base end portion 36 of the filter medium 18. The widthwise portion 64 extends along direction B. The base end 54 of the filter medium 18 is located in the widthwise portion 64. That is, the base end 54 of the filter medium 18 is located in the widthwise portion 64 beyond the filter medium fused region 52.

[0110] Each of the two axial portions 66 is formed to face a side edge portion 62 of the filter medium 18. Each of the two axial portions 66 extends along direction A. The side edge 68 of the filter medium 18 is located on the axial portion 66. In other words, the side edge portion 62 of the filter medium 18 is located on the axial portion 66 beyond the filter medium fused region 52.

[0111] The window 46 is provided in the housing 12 so as to face the non-fused region 44. Therefore, the window 46 is formed in a U-shape. Through the window 46, the user can view the base end 54 and two side edges 62 of the filter medium 18 located in the non-fused region 44. The width L4, which is the dimension of the widthwise portion 64 in the B direction, is greater than the width L2 (L4 > L2). The axial portion 66 also extends further toward the outflow port 16 than the tip end 38 of the filter medium 18.

[0112] The width direction portion 64 and the two axial direction portions 66 may be separated. Furthermore, when the filter medium fused region 52 is integrally fused to one of the two side edge portions 62 of the filter medium 18, the base end portion 36 of the filter medium 18, and the inlet port 14, the filter medium fused region 52 may be formed in an L-shape. In this case, the non-fused region 44 and the window portion 46 are formed in an L-shape corresponding to the filter medium fused region 52.

[0113] The fifth embodiment also provides the same effects as the first embodiment (see FIGS. 1 to 4B). Furthermore, the fifth embodiment also provides the following effects.

[0114] As shown in Figures 10 and 11 , because the housing 12, filter medium 18, and inlet port 14 are fused together, the fused portion between the filter medium fused region 52, the base end 36 of the filter medium 18, and the inlet port 14 is likely to have a lower fusion bonding strength than the peripheral fused region 50, which is the fused portion between the first sheet portion 20 and the second sheet portion 22. Furthermore, the fused portions between the filter medium fused region 52, the base end 36, and the side edge 62 of the filter medium 18 are likely to have a lower fusion bonding strength than the peripheral fused region 50. If fusion abnormalities occur at these fused portions, liquid 49 (see Figures 18 and 21 ) will flow into the non-fused region 44 via the base end 54 and side edge 62 of the filter medium 18. The base end 54 and side edge 62 of the filter medium 18 are located beyond the fused region 52 and in the non-fused region 44. That is, the base end 54 and side edge 62 of the filter medium 18 are not fused to the housing 12. The base end 54 and side edge 62 of the filter medium 18 are free ends located within the unfused region 44. The window 46 faces the unfused region 44. This allows the user to view the base end 54 and side edge 62 of the filter medium 18 located in the unfused region 44 through the window 46. The user can also easily check through the window 46 whether liquid 49 has flowed into the unfused region 44. This is therefore effective for early detection of abnormalities in the medical filter 90.

[0115] The width L4 of the width direction portion 64 in the direction B is greater than the width L2 of the filter medium 18 in the direction B (L4>L2). This allows the portion of the window portion 46 facing the width direction portion 64 to be larger. As a result, the width direction portion 64 can be easily seen through the window portion 46 from outside the housing 12.

[0116] If a fusion defect occurs in the fused region 52 of the filter medium, the liquid 49 will flow from the outflow region 42 into the unfused region 44. This is more effective in early detection of an abnormality in the medical filter 90. In addition, the portion of the window 46 facing the axial portion 66 can be enlarged. This makes it easier to see the axial portion 66 through the window 46 from outside the housing 12.

[0117] A medical filter 100 according to a sixth embodiment will be described with reference to FIGS.

[0118] The medical filter 100 further includes a reinforcing material 19. That is, when a liquid 49 (see FIGS. 18 and 21 ) flows into the inflow region 40, the filter medium 18 is subjected to the pressure of the liquid 49. The reinforcing material 19 is disposed in the internal space 30 to suppress deformation of the filter medium 18 due to the pressure of the liquid 49. For this reason, the reinforcing material 19 is made of a material that is harder than the filter medium 18 and has lower extensibility (tensile elongation) than the filter medium 18, as will be described later.

[0119] More specifically, the reinforcing material 19 covers the outer surface of the filter medium 18 in the outflow region 42. Because the filter medium 18 is formed in a bag shape, the reinforcing material 19 is formed in a bag shape so as to cover the outer surface of the filter medium 18. Therefore, the entire outer surface of the filter medium 18 is covered with the reinforcing material 19.

[0120] A portion of the filter medium 18 and a portion of the reinforcing material 19 overlap. That is, a portion of the outer surface of the filter medium 18 and a portion of the inner surface of the reinforcing material 19 are in contact. Specifically, the base end 36 of the filter medium 18 and the base end 37 of the reinforcing material 19 are in contact. Also, the tip end 38 side of the filter medium 18 and the tip end 55 side of the reinforcing material 19 are in contact. Furthermore, two side edge portions 62 of the filter medium 18 and the side edge portions of the reinforcing material 19 are in contact. In this case, a portion of the outer surface of the filter medium 18 and a portion of the inner surface of the reinforcing material 19 may be fused. At these locations, the filter medium 18 and the reinforcing material 19 may be molded integrally. Furthermore, as shown in FIGS. 4A and 4B , when the filter medium 18 is formed by stacking multiple flexible sheets 35, the reinforcing material 19 is arranged to cover the outer surface of the outermost flexible sheet 35.

[0121] 12 to 14, in the sixth embodiment, the central region 45 or the central portion 47 of the filtration function portion 41 is joined at the joint 21. Therefore, the portions of the filter medium 18 that are inside the base end portion 36, the tip end portion 38, and the two side edge portions 62 are not in contact with the reinforcing material 19.

[0122] When liquid 49 flows into the inflow region 40, the filter medium 18 receives the pressure of the liquid 49 and expands in directions B and C, which are perpendicular to direction A. As the filter medium 18 expands in directions B and C, the tip 38 side of the filter medium 18 (the bottom of the filter medium 18) is pulled (pulled up) toward the inflow port 14. Direction B is also the width direction of the filter medium 18 and the reinforcing material 19. Direction C is also the thickness direction of the filter medium 18 and the reinforcing material 19.

[0123] Because the reinforcing material 19 is provided, even if the filter medium 18 expands under the pressure of the liquid 49, the expansion of the filter medium 18 is suppressed inside the reinforcing material 19. In other words, the expansion of the filter medium 18 is suppressed to a shape that conforms to the inner surface of the reinforcing material 19. This makes it possible to suppress the filter medium 18 from expanding significantly in directions B and C.

[0124] When the inflow of the liquid 49 into the inflow region 40 stops, the reinforcing material 19 and the filter material 18 return to their original shapes (the shapes in the initial state).

[0125] The reinforcing material 19 is a porous body through which the liquid 49 that has passed through the filter medium 18 can pass. The pore size of the porous body that constitutes the reinforcing material 19 is the same as the pore size of the porous body that constitutes the filter medium 18. Alternatively, the pore size of the porous body that constitutes the reinforcing material 19 is larger than the pore size of the porous body that constitutes the filter medium 18. In this case, the porous body that constitutes the reinforcing material 19 is coarser than the porous body that constitutes the filter medium 18. Therefore, the reinforcing material 19 does not filter the liquid 49 that has passed through the filter medium 18. In other words, the reinforcing material 19 does not function as a filter for the liquid 49.

[0126] Furthermore, the reinforcing material 19 is a porous material that is harder than the filter medium 18 and less extensible than the filter medium 18. Therefore, when the filter medium 18 and the reinforcing material 19 are subjected to the same force (for example, the pressure of the liquid 49), the reinforcing material 19 is less likely to stretch than the filter medium 18. In other words, the reinforcing material 19 has higher rigidity against tensile forces than the filter medium 18.

[0127] The porous material constituting the reinforcing material 19 may be, for example, a nonwoven fabric made of PET. In the case of a nonwoven fabric made of PET, the diameter of the fibers constituting the nonwoven fabric is preferably about 0.3 μm to 20 μm. In addition, the weight per unit area of ​​the nonwoven fabric per 0.1 mm of thickness is 10 g / m. ２ ~60g / m ２ The weight per unit area is preferably about 20 g / m ２ ~50g / m ２ It is more preferable that the degree of

[0128] Furthermore, the surface of the porous body (e.g., nonwoven fabric) that constitutes the reinforcing material 19 may be coated with a hydrophilic polymer or an antithrombogenic material, thereby improving the permeability of platelets through the nonwoven fabric.

[0129] A pre-filter may be provided inside the filter medium 18. The pre-filter separates and removes aggregates and the like from blood. When the pre-filter is made of nonwoven fabric, the diameter of the fibers constituting the nonwoven fabric is preferably about 5 μm to 30 μm. The weight per unit area of ​​the nonwoven fabric per 0.1 mm of thickness is preferably 10 g / m. ２ ~40g / m ２ The weight per unit area is preferably about 15 g / m ２ ~35g / m ２ It is more preferable that the degree of

[0130] Alternatively, the reinforcing material 19 may be formed using a mesh-like member that is less extensible than the filter medium 18 and has a larger pore size than the filter medium 18 .

[0131] The reinforcing material 19 may be made of a porous material having lower extensibility (tensile elongation) than the filter medium 18. Therefore, the reinforcing material 19 may be made of a porous material made of a material other than PET. Alternatively, the porous material making up the reinforcing material 19 may be a porous material having lower extensibility than the filter medium 18 and made of the same material as the filter medium 18.

[0132] The tensile elongation of the reinforcing material 19 will be described in detail. When viewed from direction A, the ratio of the circumferential length of the reinforcing material 19 in a state where liquid 49 has flowed into the inflow region 40 to the circumferential length of the reinforcing material 19 in an initial state where liquid 49 has not flowed into the inflow region 40 is referred to as the tensile elongation of the reinforcing material 19. In this case, the tensile elongation of the reinforcing material 19 is preferably 0% to 40%. The tensile elongation is more preferably 0% to 35%. The tensile elongation is even more preferably 0% to 30%. The tensile elongation is even more preferably 0% to 25%. The tensile elongation is even more preferably 0% to 20%. By setting the tensile elongation of the reinforcing material 19 in this manner, it is possible to effectively suppress the expansion of the filter medium 18 in directions B and C when liquid 49 flows into the inflow region 40.

[0133] The filter medium fused region 52 is integrally fused to the base end 36 of the filter medium 18, the base end 37 of the reinforcing material 19, and the inlet port 14. Although schematically illustrated in Figure 13, strictly speaking, in the filter medium fused region 52, a portion of the housing 12 (the first sheet portion 20 and the second sheet portion 22) is impregnated with the filter medium 18 and the reinforcing material 19. Therefore, at the location of the filter medium fused region 52 where the inlet port 14 is located, a portion of the housing 12 is impregnated with the filter medium 18 and the reinforcing material 19, thereby integrally fused to the housing 12, the filter medium 18, the reinforcing material 19, and the inlet port 14. At the location of the filter medium fused region 52 other than where the inlet port 14 is located, a portion of the housing 12 is impregnated with the filter medium 18 and the reinforcing material 19, thereby integrally fused to the first sheet portion 20, the filter medium 18, the reinforcing material 19, and the second sheet portion 22.

[0134] In the medical filter 100 according to the sixth embodiment, when the filter medium 18 filters a liquid 49 such as blood, the filter medium 18 expands in directions B and C under the pressure of the liquid 49. Furthermore, because the reinforcing material 19 covers the outer surface of the filter medium 18, the reinforcing material 19 also expands in directions B and C under the pressure of the liquid 49. Furthermore, the reinforcing material 19 has lower extensibility (tensile elongation) than the filter medium 18. Therefore, deformation of the filter medium 18 due to the pressure of the liquid 49 when the liquid 49 passes through the filter medium 18 can be suppressed. In other words, the expansion of the filter medium 18 can be suppressed inside the reinforcing material 19. This prevents the filter medium 18 from expanding in directions B and C under the pressure of the liquid 49.

[0135] The sixth embodiment also provides the same effects as the first embodiment (see FIGS. 1 to 4B). Furthermore, the sixth embodiment also provides the following effects.

[0136] If the reinforcing material 19 is not provided, when the liquid 49 that has flowed into the inflow region 40 passes through the filter medium 18, the pressure of the liquid 49 may cause the filter medium 18 to deform. Specifically, the pressure of the liquid 49 passing through the filter medium 18 may cause the filter medium 18 to expand in directions B and C that are perpendicular to the axial direction (direction A) of the inflow port 14. The expansion of the filter medium 18 in directions B and C may increase the pore size of the porous body that constitutes the filter medium 18, which may reduce the filtering performance of the filter medium 18.

[0137] In contrast, in the sixth embodiment, as shown in Figures 12 to 14, a reinforcing material 19 is disposed in the internal space 30. The reinforcing material 19 allows the liquid 49 that has passed through the filter medium 18 to pass through, and covers the filter medium 18 in the outflow region 42. This makes it possible to prevent the filter medium 18 from being deformed by the pressure of the liquid 49 that flows into the inflow region 40 and passes through the filter medium 18. As a result, it is possible to prevent a decrease in the filtering performance of the filter medium 18 due to deformation of the filter medium 18.

[0138] The reinforcing material 19 has a lower extensibility than the filter medium 18, and therefore can effectively prevent the filter medium 18 from being deformed by the pressure of the liquid 49 that flows into the inflow region 40 and passes through the filter medium 18.

[0139] The reinforcing material 19 is formed in a bag shape so as to cover the outer surface of the bag-shaped filter medium 18. This allows the filter medium 18 to be easily covered with the reinforcing material 19.

[0140] The base end 36 of the filter medium 18, the inlet port 14, and the base end 37 of the reinforcing member 19 are integrally fixed to the periphery 28 of the housing 12. This allows the filter medium 18, the inlet port 14, and the reinforcing member 19 to be easily fixed inside the housing 12.

[0141] Since a portion of the outer surface of the filter material 18 is in contact with a portion of the inner surface of the reinforcing material 19, deformation of the filter material 18 due to the pressure of the liquid 49 passing through the filter material 18 can be effectively prevented.

[0142] By integrally molding a portion of the filter medium 18 and a portion of the reinforcing material 19, the filter medium 18 and the reinforcing material 19 can be easily manufactured.

[0143] The filter medium 18 is a porous body that allows the liquid 49 to pass through, and the reinforcing material 19 is a porous body that has a pore size larger than that of the filter medium 18. This prevents the liquid 49 that has passed through the filter medium 18 from being blocked by the reinforcing material 19.

[0144] If the reinforcing material 19 is a nonwoven fabric, the filter medium 18 can be easily covered with the reinforcing material 19 in the outflow region 42 .

[0145] A medical filter 110 according to a seventh embodiment will be described with reference to Figures 15 to 21. Of Figures 15 to 21, Figures 15 and 16 show the medical filter 110 in an initial state in which no liquid 49 has been supplied. Figures 17 to 21 show the medical filter 110 in a state in which the liquid 49 has been supplied.

[0146] In the medical filter 110 according to the seventh embodiment, the joint 21 joins one wall of the reinforcing material 19 in the thickness direction (C direction) of the filter material 18, the filter material 18, and the other wall of the reinforcing material 19 in the C direction. Specifically, the joint 21 joins one inner wall of the reinforcing material 19 in the C direction, the central region 45 or center 47 of the filtering function unit 41, and the other inner wall of the reinforcing material 19 in the C direction. In this case, the joint 21 integrally fuses one inner wall of the reinforcing material 19, the central region 45 or center 47 of the filtering function unit 41, and the other inner wall of the reinforcing material 19. Although schematically illustrated in FIGS. 15 and 16 , strictly speaking, at the joint 21, a portion of the reinforcing material 19 is impregnated into the filtering function unit 41. By impregnating a portion of the reinforcing material 19 into the filtration function portion 41, the reinforcing material 19 and the filtration function portion 41 are fused together at the joint 21. Note that the joint 21 may join one wall portion or the other wall portion of the reinforcing material 19 to the central region 45 or the central portion 47 of the filtration function portion 41.

[0147] In the medical filter 110, when liquid 49 flows into the inflow region 40, the filter medium 18 receives the pressure of the liquid 49 and expands in directions B and C, which are perpendicular to direction A. As the filter medium 18 expands in directions B and C, which are perpendicular to direction A, the tip 38 side of the filter medium 18 (the bottom of the filter medium 18) is pulled (pulled up) toward the inflow port 14. In Figures 18 to 21, the shapes of the filter medium 18 and the reinforcing material 19 when liquid 49 has flowed into the inflow region 40 are shown by solid lines, and the shapes of the filter medium 18 and the reinforcing material 19 in the initial state when liquid 49 has not flowed into the inflow region 40 are shown by dashed double-dashed lines.

[0148] As described above, the reinforcing material 19 covers the outer surface of the filter medium 18. Therefore, when liquid 49 flows into the inflow region 40 and passes through the filter medium 18, the reinforcing material 19 also expands in directions B and C due to the pressure of the liquid 49. More specifically, when liquid 49 flows into the inflow region 40, the pressure of the liquid 49 is evenly applied inside the filter medium 18. As a result, the filter medium 18 tends to expand in directions B and C. As described above, the reinforcing material 19 is provided on the outside of the filter medium 18 and is harder and has a lower tensile elongation than the filter medium 18. This allows the pressure of the liquid 49 to be evenly applied, thereby preventing the filter medium 18 from expanding in directions B and C. Furthermore, the tip 55 side (bottom) of the reinforcing material 19 is relatively soft. Therefore, when liquid 49 flows into the inflow region 40 and the reinforcing material 19 is subjected to the pressure of the liquid 49, the tip 55 side of the reinforcing material 19 is pulled up toward the inflow port 14. Figure 18 shows a state in which the tip 55 side (bottom) of the reinforcing material 19 and the tip 38 side (bottom) of the filter medium 18 are slightly raised toward the inlet port 14 compared to before the liquid 49 flows into the inlet region 40 (two-dot chain line). Figure 19 shows a state in which the bottom of the reinforcing material 19 and the bottom of the filter medium 18 are raised flat toward the inlet port 14. Figure 20 shows a state in which the bottom of the reinforcing material 19 and the bottom of the filter medium 18 are raised toward the inlet port 14, with the central portions of the bottoms recessed toward the inlet port 14.

[0149] When the liquid 49 flows into the inlet region 40, the reinforcing member 19 expands into a hexagonal shape when viewed from direction B (see FIG. 18 ). Also, the reinforcing member 19 expands into a hexagonal shape when viewed from the axial direction of the inlet port 14 (see FIG. 21 ).

[0150] However, as described above, the joint 21 joins one inner wall portion of the reinforcing material 19, the central region 45 or central portion 47 of the filtration function portion 41, and the other inner wall portion of the reinforcing material 19. Therefore, the reinforcing material 19 expands in a hexagonal shape to surround the joint 21. That is, when viewed from direction B, the portion between the joint 21 and the distal end 55 and the portion between the joint 21 and the proximal end 37, sandwiching the joint 21, each expand (see FIG. 18 ). Furthermore, when viewed from direction A, the portion between the joint 21 and one side edge and the portion between the joint 21 and the other side edge, sandwiching the joint 21, each expand (see FIG. 21 ).

[0151] Therefore, when the liquid 49 is flowing into the inflow region 40, the reinforcing material 19 has two parallel portions 51 and three tapered portions 53. In other words, when the liquid 49 is flowing into the inflow region 40, the reinforcing material 19 has two parallel portions 51 and three tapered portions 53.

[0152] Each of the two parallel portions 51 is a portion of the reinforcing material 19 that is parallel to the central axis 34. Each of the two parallel portions 51 is a flat portion that is parallel to the central axis 34. The two parallel portions 51 face each other across the central axis 34. When viewed from direction C, each of the two parallel portions 51 is formed so as to surround the joint portion 21 (see FIG. 17 ). Compared to the initial state, each of the two parallel portions 51 is spaced apart from the central axis 34 in direction C. That is, each of the two parallel portions 51 protrudes in direction C compared to the initial state.

[0153] Of the three tapered portions 53, one tapered portion 57 is connected to two parallel portions 51. The tapered portion 57 is connected to the two parallel portions 51 so as to surround the two parallel portions 51. The tapered portion 57 is inclined with respect to the central axis 34. Specifically, the base end side of the tapered portion 57 connects the base end portion 37 of the reinforcing material 19 to the two parallel portions 51. Therefore, the base end side of the tapered portion 57 is inclined from the two parallel portions 51 toward the base end portion 37 of the reinforcing material 19. Furthermore, the tip side of the tapered portion 57 is inclined from the two parallel portions 51 toward the tip portion 55 of the reinforcing material 19. Furthermore, the side portion of the tapered portion 57 between the tip side and the base side of the tapered portion 57 is inclined toward the side edge of the reinforcing material 19.

[0154] Of the three tapered portions 53, the remaining two tapered portions 59 are connected to one of the two parallel portions 51 so as to be surrounded by the two parallel portions 51 when viewed from the C direction. The two tapered portions 59 are connected to the joint portion 21. The two tapered portions 59 face each other with the joint portion 21 in between. The two tapered portions 59 are inclined with respect to the central axis 34. Specifically, the center portion of each of the two tapered portions 59 is connected to the joint portion 21. The edge portion of each of the two tapered portions 59 is connected to one of the joint portions 21 of the two parallel portions 51. Each of the two tapered portions 59 is inclined from the parallel portion 51 toward the joint portion 21.

[0155] The reinforcing material 19 does not have any folds to form boundaries between the two parallel portions 51 and the three tapered portions 53 (tapered portion 57 and two tapered portions 59). When the liquid 49 flows into the inflow region 40 and is subjected to the pressure of the liquid 49 that has passed through the filter medium 18, the two parallel portions 51 and the three tapered portions 53 are formed.

[0156] 18 , for each of the two parallel portions 51, the width L61 of the portion closer to the tip end 55 than the joint 21 in the direction A is greater than the width L71 of the base end and the width L81 of the tip end of the tapered portion 57 (L61 > L71, L61 > L81). For each of the two parallel portions 51, the width L62 of the portion closer to the base end 37 than the joint 21 in the direction A is greater than the width L71 of the base end and the width L81 of the tip end of the tapered portion 57 (L62 > L71, L62 > L81).

[0157] Furthermore, for each of the two parallel portions 51, in the direction A, the widths L61 and L62 are larger than the widths L72 and L82 between the parallel portions 51 of the two tapered portions 59 and the joint portion 21 (L61 > L72, L61 > L82, L62 > L72, L62 > L82).

[0158] 21 , for each of the two parallel portions 51, the widths L91 and L92 of both sides of the joint 21 in the direction B are greater than the widths L101 and L111 of the sides of the tapered portion 57 (L91>L101, L91>L111, L92>L101, L92>L111). Also, for each of the two parallel portions 51, the widths L91 and L92 in the direction B are greater than the widths L102 and L112 between the parallel portions 51 of the tapered portion 59 and the joint 21 (L91>L102, L91>L112, L92>L102, L92>L112).

[0159] When liquid 49 has flowed into inflow region 40, two parallel portions 51 and three tapered portions 53 (tapered portion 57 and two tapered portions 59) are formed in reinforcing material 19, so even if filter medium 18 expands under the pressure of liquid 49, the expansion of filter medium 18 is suppressed inside reinforcing material 19. In other words, the expansion of filter medium 18 is suppressed to a shape that follows the inner surface of reinforcing material 19. This makes it possible to suppress large expansion of filter medium 18 in directions B and C.

[0160] When the inflow of the liquid 49 into the inflow region 40 stops, the reinforcing material 19 and the filter medium 18 return to their original shapes (the shapes in the initial state).

[0161] The seventh embodiment also provides the same effects as the sixth embodiment (see FIGS. 12 to 14). In addition, in the seventh embodiment, the joint 21 joins the reinforcing member 19 and the filter medium 18, so that deformation of the filter medium 18 due to the pressure of the liquid 49 passing through the filter medium 18 can be more effectively prevented.

[0162] Furthermore, the parallel portion 51 is parallel to the direction A, and the tapered portion 53 is inclined with respect to the direction A and is connected to the parallel portion 51 so as to surround the parallel portion 51. This effectively prevents the filter medium 18 from expanding in the directions B and C perpendicular to the direction A due to the pressure of the liquid 49 when the liquid 49 flows into the inflow region 40.

[0163] A medical filter 120 according to an eighth embodiment will be described with reference to FIG.

[0164] In the medical filter 120 according to the eighth embodiment, the joint 21 joins one wall of the housing 12 in the thickness direction (C direction) of the filter medium 18, one wall of the reinforcing material 19 in the C direction, the filter medium 18, the other wall of the reinforcing material 19 in the C direction, and the other wall of the housing 12 in the C direction. More specifically, in the eighth embodiment, the inner wall of the first sheet portion 20, which is one wall of the housing 12, one inner wall of the reinforcing material 19 in the C direction, the filter medium 18, the other inner wall of the reinforcing material 19 in the C direction, and the inner wall of the second sheet portion 22, which is the other wall of the housing 12, are joined. In this case, the inner wall of the first sheet portion 20, one inner wall of the reinforcing material 19, the filter medium 18, the other inner wall of the reinforcing material 19, and the inner wall of the second sheet portion 22 are fused together. 22 is a schematic illustration, strictly speaking, a portion of the housing 12 (the first sheet portion 20 and the second sheet portion 22) is impregnated with the filter medium 18 and the reinforcing material 19. By impregnating a portion of the housing 12 with the filter medium 18 and the reinforcing material 19, the housing 12, the reinforcing material 19, and the filtering function unit 41 are fused together at the joint 21. Note that the joint 21 may join one or the other wall of the housing 12 and the reinforcing material 19 to the central region 45 or the central portion 47 of the filtering function unit 41.

[0165] The eighth embodiment also achieves the same effects as the sixth and seventh embodiments (see FIGS. 12 to 21). In the eighth embodiment, the joint 21 joins the housing 12, the reinforcing member 19, and the filter medium 18, thereby more effectively preventing the filter medium 18 from being deformed by the pressure of the liquid 49 passing through the filter medium 18.

[0166] A medical filter 130 according to the ninth embodiment will be described with reference to Fig. 23. The medical filter 130 has a configuration in which a reinforcing member 19 is added to the medical filter 80 according to the third embodiment (see Figs. 7 and 8). The ninth embodiment also provides the effects of the third embodiment and the sixth to eighth embodiments (see Figs. 12 to 22).

[0167] A medical filter 135 according to a tenth embodiment will be described with reference to FIG.

[0168] In the medical filter 135 according to the tenth embodiment, similar to the medical filter 85 according to the fourth embodiment (see FIG. 9), the filter medium fused region 52 is integrally fused to the base end 36 and two side edge portions 62 of the filter medium 18 and to the inlet port 14. In addition, the filter medium fused region 52 is integrally fused to the base end and two side edge portions of the reinforcing material 19. In the tenth embodiment, the same effects as those of the first, third, and sixth to eighth embodiments can be obtained.

[0169] A medical filter 140 according to the eleventh embodiment will be described with reference to Fig. 25. The medical filter 140 has a configuration in which a reinforcing member 19 is added to the medical filter 90 according to the fifth embodiment (see Figs. 10 and 11). The eleventh embodiment also provides the effects of the fifth to eighth embodiments (see Figs. 10 to 22).

[0170] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the gist of the present disclosure or the gist of the present disclosure derived from the content of the claims and their equivalents.

Claims

1. A medical filter comprising: a housing having an internal space; an inlet port fixed to the peripheral edge of the housing for allowing liquid to flow into the internal space from outside the housing; a filter material fixed to the housing and arranged in the internal space; and an outlet port fixed to the peripheral edge for allowing the liquid that has passed through the filter material to flow out to the outside, wherein the filter material is formed in a bag shape and the internal space is divided into an inlet region into which the liquid flows in via the inlet port and an outlet region from which the liquid that has passed through the filter material flows out to the outside via the outlet port, so that the interior of the filter material is formed as the inlet region, and the medical filter comprises a joint that joins parts of the filter material that face each other on the inside.

2. A medical filter according to claim 1, wherein the filter material has a filtering function portion surrounded by the outflow region within the internal space, a first end portion which is one end of the filter material and the inlet port are fixed to the peripheral portion, the direction from the first end portion toward the second end portion which is the other end of the filter material is defined as the length direction of the filter material, and the direction perpendicular to the thickness direction and the length direction of the filter material is defined as the width direction of the filter material, and the joint portion is located in a region where the central region when the filtering function portion is divided into thirds in the length direction overlaps with the central region when the filtering function portion is divided into thirds in the width direction, as viewed from the thickness direction.

3. A medical filter according to claim 2, wherein the joint is located at the center of the filtering function section when viewed in the thickness direction.

4. A medical filter according to any one of claims 1 to 3, wherein the joint joins a wall portion on one side of the housing in the thickness direction of the filter material, the filter material, and a wall portion on the other side of the housing in the thickness direction.

5. A medical filter according to any one of claims 1 to 3, further comprising a reinforcing material through which the liquid that has passed through the filter material can pass and which suppresses deformation of the filter material due to the pressure of the liquid passing through the filter material, the reinforcing material having a parallel portion and a tapered portion connected to the parallel portion when the liquid is passing through.

6. A medical filter according to claim 5, wherein the reinforcing material has lower extensibility than the filter material and is formed in a bag shape so as to cover the filter material in the outflow region.

7. A medical filter according to claim 6, wherein the base end of said filter medium, said inlet port, and the base end of said reinforcing member are integrally fixed to said peripheral edge of said housing.

8. A medical filter according to claim 6, wherein the joint joins a wall portion on one side of the reinforcing material in the thickness direction of the filter material, the filter material, and a wall portion on the other side of the reinforcing material in the thickness direction.

9. A medical filter according to claim 6, wherein the joint joins a wall portion on one side of the housing in the thickness direction of the filter material, a wall portion on one side of the reinforcing material in the thickness direction, the filter material, a wall portion on the other side of the reinforcing material in the thickness direction, and a wall portion on the other side of the housing in the thickness direction.

10. A medical filter according to claim 6, wherein the parallel portion is parallel to the axial direction of the inlet port, and the tapered portion is inclined with respect to the axial direction and is connected to the parallel portion so as to surround the parallel portion.

11. A medical filter according to claim 6, wherein the filter material is a porous material that allows the liquid to pass through, and the reinforcing material is a porous material having a pore size larger than the pore size of the filter material.

12. A medical filter according to claim 11, wherein the reinforcing material is a nonwoven fabric.

13. A medical filter according to any one of claims 1 to 3, wherein the joints fuse together portions of the filter material that face each other inside the filter material.

Images