TW202335689A - Filter applicable for drip chamber - Google Patents

Abstract

The object of the present application is to provide a filter 10 which is applicable for drip chamber and comprises a top plate portion 11, a lower ring 12, a plurality of ribs 13 for connecting the top plate portion 11 and the lower ring 12 and forming a plurality of slits 15 therebetween, and an intermediate ring 14 extending in the circumferential direction and connecting the ribs with each other. The rib 13 has an outer peripheral portion 13a and a triangular inner peripheral portion 13b. The angle formed between the extending direction of the side surface and the radial direction is larger than an angle formed between the outer peripheral portion 13a and the radial direction. The radial thickness of the rings 14 is thinner than a radial thickness of the ribs 13 located at the place that the rings 14 are formed.

Description

Filter for drip chamber

The present disclosure relates to a filter for drip chamber.

A filter is installed in the drip chamber of the extracorporeal circuit to remove clots or foreign matter from the blood. As filters for the drip chamber, molded filters and mesh filters are mainly used.

Whether it is a molded filter or a mesh filter, it is required to properly remove foreign matter while also allowing blood to flow smoothly and to easily remove air bubbles during priming. If blood cannot flow smoothly and becomes stagnant, coagulation may easily occur in this part. In addition, if the air bubble detachability is poor, the operability during pre-charging will be reduced. If it is used with trapped air bubbles, it may cause poor blood flow and cause coagulation.

Therefore, various studies have been conducted on the shape of various filters in an attempt to improve the flow of blood and expel air bubbles quickly. For example, in the case of a molded filter, research has been conducted on making the upper surface of a transverse member forming a slit an inclined surface so that blood can flow smoothly through the slit portion (see, for example, Patent Document 1). In addition, in the case of a mesh filter, attempts have been made to make it less likely for blood to accumulate in a three-dimensional shape by combining it with a support member (for example, see Patent Document 2).

Patent Document 1: Japanese Patent Publication No. 2002-525192

Patent Document 2: Japanese Patent Application Laid-Open No. 9-140788

-Technical problem to be solved by the invention-

However, conventional filters do not take into account the influence of the entire transverse component on retention. When a surface intersecting the flow direction of blood exists, blood retention is affected not only by the surface on the upstream side but also by the entire surface. For example, there may be a pocket area directly beneath the transverse member where blood flow is stagnant. Even if the upper surface of the transverse member is an inclined surface, it is difficult to prevent stagnation in the area directly below the transverse member. Furthermore, not only the transverse members but also the lower end surfaces of the ribs and the back side of the top plate may cause retention, but the above cases are not considered.

Air bubbles trapped on the non-mesh top surface are also a big problem for mesh filters with support members. In addition, the manufacturing process of combining the supporting components and the mesh is required, which becomes the main reason for the cost increase. Research has also been conducted on integrating the mesh filter and the support member by insert molding, but in this case, advanced molding technology is required. Moreover, retention problems also occur in insert molding.

An object of this disclosure is to realize a filter for an intravenous drip chamber in which blood flows smoothly and is less likely to stagnate.

-Technical means used to solve technical problems-

In the first aspect of the drip chamber filter of the present disclosure, it includes a top plate part, a lower ring, a plurality of ribs, and an intermediate ring. The plurality of ribs connect the top plate part and the lower ring, and a plurality of slits are formed between the plurality of ribs. The middle ring connects the ribs to each other in the circumferential direction; the closer the ribs are to the radially inner side, the smaller the circumferential width is. The angle formed is greater than the angle formed by the extending direction of the side surface of the outer peripheral portion and the radial direction; the radial thickness of the intermediate ring is thinner than the radial thickness of the rib located at the formation position of the intermediate ring.

According to the first aspect of the drip chamber, the radial thickness of the intermediate ring is thinner than the radial thickness of the ribs located at the formation position of the intermediate ring, so that the area hidden under the lower side of the intermediate ring that is prone to stagnation becomes smaller. Therefore, it is possible to prevent blood from being easily retained by the intermediate ring. Since the inner peripheral portion of the rib has a triangular shape in which the angle between the extending direction of the side surface and the radial direction is larger than the angle between the extending direction of the outer peripheral portion and the radial direction, the width of the slit becomes wider at the inner peripheral portion of the rib. Therefore, blood can flow smoothly in the slits, making stagnation less likely to occur.

In a second aspect of the drip chamber filter, the filter includes a top plate, a lower ring, and a plurality of ribs. The plurality of ribs connect the top plate and the lower ring. A plurality of slits are formed between the plurality of ribs. The top plate portion It has an inclined lower surface that goes downward toward the center and a top plate opening that penetrates up and down.

In the second aspect of the drip chamber filter, since downward blood flow easily occurs along the inclined lower surface of the top plate portion, compared with the case where the lower surface of the top plate portion is perpendicular to the blood flow, it can be made Detention is unlikely to occur. Since the inflow of blood from the opening of the top plate also causes a downward flow, stagnation can be reduced on the entire lower surface of the top plate.

In the second aspect of the drip chamber filter, the top plate may have an inclined upper surface that becomes lower toward the center. By adopting such a structure, blood can be easily guided to the top plate opening.

In the second aspect of the drip chamber filter, the top plate opening can be formed in a shape that is formed in the radial direction and has a radial length longer than a circumferential width. By adopting such a structure, blood flowing toward the center of the upper surface of the top plate portion can easily flow into the top plate opening, so that stagnation can be further made less likely to occur.

In a third aspect of the drip chamber filter, the filter includes a top plate, a lower ring, and a plurality of ribs. The plurality of ribs connect the top plate and the lower ring. A plurality of slits are formed between the plurality of ribs. The ribs are at the lower end. There is a sloped area whose radial thickness gradually decreases toward the lower side to form a space on the lower side.

According to the third aspect of the intravenous drip chamber filter, the rib has an inclined region in which the radial thickness gradually becomes smaller toward the downward direction. Therefore, the lower end surface of the rib does not become a surface perpendicular to the blood flow, making retention less likely to occur. Since a space is formed on the lower side of the rib, the connection between the lower end of the filter and the chamber body does not become step-shaped, and as a result, retention can be further made less likely to occur.

In the third aspect of the drip chamber filter, the filter further includes an intermediate ring formed between the top plate part and the lower ring; the outer peripheral surface of the rib may have a step portion protruding radially outward at a position intersecting the intermediate ring. . By adopting such a structure, deformation of the ribs can be easily suppressed and the circumferential width of the slits can be made uniform, thereby improving the function of preventing blood clots and the like.

In the fourth aspect of the filter for an instillation chamber of the present disclosure, the filter includes a mesh filter and a filter holding part that holds the mesh filter in a cylindrical shape; the filter holding part has a top plate, a lower ring, and a connecting top plate. and the support portion of the lower ring; the position of the lower surface of the top plate portion is highest at the outer edge, and the top plate portion has a top plate opening that penetrates up and down; the top plate opening has a minimum gap width at the lower end that is smaller than the upper end; the mesh filter The inner surface is secured against the outer surface of the filter holder.

In the fourth aspect of the drip chamber filter, since the lower surface of the top plate is positioned highest at the outer edge, an upwardly protruding depression that causes blood to accumulate is not formed at the upper end of the filter, so that accumulation can be suppressed. The top plate part has a top plate opening that penetrates up and down, and the top plate opening has a smaller minimum gap width at the lower end than at the upper end. Therefore, the ability to prevent the passage of clots or foreign matter is high, and air bubbles are easily discharged during prefilling. Since the inner surface of the mesh filter is fixed in close contact with the outer surface of the filter holder, it is easy to install the mesh filter on the filter holder and the mesh filter is not easily deformed, so the blood can flow smoothly pass through.

In the fourth aspect of the drip chamber filter, a plurality of top plate openings can be formed on the circumference around the center of the top plate, the hole wall on the outer edge side is a vertical surface, and the hole wall on the center side is a cross-section. An inclined surface that is inclined downward toward the hole wall on the outer edge side. By adopting such a structure, the thickness of the outer edge portion of the top plate portion can be made uniform and deformation during molding can be suppressed. Therefore, the mesh filter can be easily fixed to the outer surface of the top plate portion.

In the fourth aspect of the drip chamber filter, the top plate portion may have a lower surface convex portion protruding from a position of the top plate opening toward a center of the top plate portion and gradually increasing in height. By adopting such a structure, air bubbles that reach the top plate portion can easily move to the outer edge portion where the top plate opening is located, and the air bubbles can be easily removed.

In the fourth aspect of the drip chamber filter, the outer diameter of the lower ring may be consistent with the outer diameter of the top plate portion. By adopting such a structure, the mesh filter can be fixed in a cylindrical shape, and the amount of blood passing through the mesh filter is substantially constant. Therefore, blood is less likely to remain in the filter, and the occurrence of coagulation can be suppressed.

In the fourth aspect of the drip chamber filter, you may have a flange portion protruding from the lower portion in the radial direction outward, the flange portion having a notch portion on the outer peripheral surface, and the notch portion having a circumferential position consistent with the pillar portion. mode settings. By adopting such a structure, it is easy to clamp the filter holding part with a clamp and rotate it, so that the filter net can be wound around the filter holding part and fixed in close contact with the filter holding part.

-Effects of the invention-

According to the filter of the present disclosure, retention in the filter for the drip chamber can be made less likely to occur.

As shown in FIG. 1 , the intravenous drip chamber according to the first embodiment includes a chamber body 200 and a filter 10 accommodated inside the chamber body 200 . The chamber body 200 has a cylindrical part 201 and an upper cover 203 attached to the upper part of the cylindrical part 201 . The upper cover 203 has a plurality of ports 231 for connecting the hoses 301 . The number and arrangement of the ports 231 provided on the upper cover 203 are not particularly limited. The port 231 may be provided on the side surface of the upper cover 203 or the side surface of the cylindrical part 201 . The lower end of the cylindrical portion 201 decreases in diameter as it goes downward, and a hose 302 is connected to the lower end. The filter 10 is embedded in the lower end of the cylindrical portion 201 . In addition, although the example shown is that the chamber main body is formed from two parts, the upper cover and the cylindrical part, it may also be formed from more parts.

As shown in FIGS. 2 to 8 , the filter 10 is a molded filter having a top plate 11 , a lower ring 12 and a plurality of ribs 13 . The ribs 13 connect the top plate part 11 and the lower ring 12, and a slit 15 as an opening is formed between adjacent ribs 13.

Two intermediate rings 14 are formed between the top plate portion 11 and the lower ring 12 to circumferentially connect the ribs 13 to each other. Therefore, the slit 15 is divided into three parts in the height direction by the intermediate ring 14 . Each part divided in the height direction of the slit 15 has a longitudinal shape with a height sufficiently larger than the circumferential width. Therefore, the direction in which the longitudinal slit 15 extends is not in contact with the blood and priming liquid (Priming Liquid). ) direction of flow is orthogonal. The bubbles captured in the slit 15 are pushed by the flow of the liquid and move in the up and down direction in the slit 15. Therefore, the bubbles can easily pass through the slit 15, and the detachability of the bubbles is improved.

By forming the intermediate ring 14, deformation of the rib 13 can be easily suppressed and the width of the slit 15 can be made uniform. The number of intermediate rings 14 may be appropriately selected depending on the height of the filter 10 and the like, and may be one or three or more. However, from the viewpoint of making it difficult for bubbles to remain, the length in the height direction of one slit 15 divided in the height direction by the intermediate ring 14 is preferably 10% or more of the height of the filter 10, and more preferably 20%. %above. It should be noted that, if deformation of the ribs 13 can be sufficiently prevented, the intermediate ring 14 does not need to be provided.

As shown in FIG. 5 , the rib 13 has an outer peripheral surface extending in the circumferential direction and a side surface extending radially inward. The rib 13 has a columnar shape with a circumferential width that decreases toward the radially inner side. The rib 13 has a substantially pentagonal cross section formed by combining a substantially isosceles trapezoidal outer peripheral portion 13a and a substantially triangular inner peripheral portion 13b. The angle θ ₂ formed by the extending direction of the side surface of the inner peripheral portion 13 b and the radial direction is larger than the angle θ ₁ formed by the extending direction of the side surface of the outer peripheral portion 13 a and the radial direction. Therefore, the circumferential width of the slits 15 formed between the ribs 13 is longer on the radially inner side than on the radial outer side. In the present embodiment, the circumferential width of the slit 15 is substantially constant at the outer peripheral portion, or becomes slightly smaller toward the radially inward side, while the circumferential width of the slit 15 decreases toward the inner peripheral portion 13b. becomes larger radially inward. It should be noted that the circumferential width of the slit 15 can be appropriately determined according to the required characteristics. For example, it can be about 0.1 mm to 0.5 mm on the outer circumferential surface and about 0.1 mm to 2.0 mm on the inner circumferential surface. The number of ribs 13 can be appropriately selected taking into account the slit width and the diameter of the filter 10 .

By making the rib 13 have a cross-sectional shape that is a combination of a substantially isosceles trapezoidal outer peripheral portion 13a and a substantially triangular inner peripheral portion 13b, when the radial thickness of the ribs is the same, it is comparable to a rib having a substantially triangular cross-section. This shape increases strength and resists deformation. Unlike ribs, which have a substantially triangular cross section, they can form portions with a constant slit width, thereby improving the foreign matter blocking function. On the other hand, compared with a rib having a substantially isosceles trapezoidal cross section, the slit width can be increased radially inward, so blood can flow easily and stagnation is less likely to occur. Since the angle formed by the outer peripheral surface of the rib and the side surface is larger than that of a rib with a substantially triangular cross-section, damage to the blood cells caused by the edge is less likely to occur. In addition, the inner end of the inner peripheral part 13b can be formed in a slightly rounded shape.

The middle ring 14 is a large obstacle to the flow of blood from above to below. Therefore, a pocket-shaped area where the flow is stagnant is likely to occur on the lower side of the intermediate ring 14 . When the width of the slit 15 gradually increases toward the center, if the intermediate ring 14 is present throughout the entire radial direction of the rib 13, the portion of the slit 15 filled by the intermediate ring 14 will become larger, making stagnation more likely to occur. . In this embodiment, the radial thickness of the intermediate ring 14 is thinner than the radial thickness of the rib 13 at the position where the intermediate ring 14 is formed. The intermediate ring 14 does not exist in the inner peripheral portion 13 b and only in the outer edge portion of the outer peripheral portion 13 a. There are intermediate rings. Since the intermediate ring 14 connects the portion of the outer peripheral portion 13b with a narrow circumferential width of the slit 15, the portion of the intermediate ring 14 filling the slit 15 can be reduced compared to an intermediate ring connecting the entire radial width of the rib 13. Therefore, It can make detention less likely to occur.

As shown in FIG. 6 , the outer peripheral surface of the rib 13 has a step at a position where the intermediate ring 14 is formed. However, there is no step on the inner peripheral surface of the rib 13 at the position where the intermediate ring 14 is formed. In the interior of the filter 10, the ribs 13 are connected flatly without forming steps, thereby smoothing the flow of blood and making retention less likely to occur. The detachability of bubbles has also been improved. If a structure having a step is adopted on the outer peripheral surface of the rib 13, the strength of the filter 10 can be easily improved, but the step may not be formed. A structure with several steps on the inside of the rib 13 may also be adopted.

The rib 13 of this embodiment has an inclined region 18 at the lower end. The radial thickness of the inclined region 18 gradually becomes smaller toward the downward direction, and the radial thickness becomes approximately zero near the lower end of the lower ring 12 . As shown in FIG. 7 , by forming the inclined area 18 , a space 19 is created on the lower side of the rib 13 . The filter 10 is generally fixed to the chamber body 200 by inserting the lower ring 12 into the groove portion 201a formed in the cylindrical portion 201. Therefore, the inclined surface forming the inclined region 18 and the inner wall surface of the chamber body are connected smoothly and substantially without any step. When there is no inclined region 18 and the radial thickness of the rib 13 is uniform up to the lower end, the lower end surface of the rib 13 becomes a surface substantially perpendicular to the flow direction, and a step occurs at the lower end of the rib 13 . In this case, if the lower end of the rib 13 is aligned with the lower end of the lower ring 12 and the lower surface of the groove 201 a is expanded to the inner peripheral end of the rib 13 , a step will not be generated at the lower end of the rib 13 , but the slit 15 The lower end will be blocked and create steps. Any step can cause blood to stagnate. However, as shown in FIG. 7 , the rib 13 of this embodiment can prevent a step from being generated at the lower end of the rib 13 and can suppress the occurrence of stagnation. It should be noted that, in this embodiment, the upper end of the inclined region 18 coincides with the upper end of the lower ring 12, but they may not coincide with each other. The position where the radial thickness of the lower ring 12 is 0 may not be completely consistent with the lower end of the lower ring 12 . The radial thickness of the rib 13 may not be completely zero.

The inner peripheral surface of the lower ring 12 is preferably connected to the outer peripheral surface of the rib 13 without any step. In this way, the lower end of the slit 15 is not blocked by the upper surface of the lower ring 12, so that retention is less likely to occur. In this embodiment, the notch 16 is formed in the outer peripheral surface of the lower ring 12 . The notch 16 corresponds to a gate portion for injecting resin during molding, and is formed into a concave shape to prevent gate burrs from protruding from the outer peripheral surface of the lower ring 12 .

As shown in FIG. 8 , in this embodiment, the lower surface 22 of the top plate portion 11 is an inclined lower surface that becomes lower toward the center. The air bubbles that move upward inside the filter 10 and reach the top plate portion 11 are led radially outward by the lower surface 22 of the top plate portion 11 that is an inclined surface that gradually becomes higher from the center toward the outer edge. In the filter 10 of this embodiment, the slit 15 extends to the lower surface 22 of the top plate part 11 . Therefore, the air bubbles that have reached the outer edge of the top plate portion 11 are easily discharged from the slit 15 to the outside of the filter. During use, the blood flowing into the filter 10 from the upper end of the slit 15 flows downward along the inclined lower surface 22. Therefore, the flow of blood on the lower side of the top plate 11 becomes smooth and stagnation is less likely to occur. .

The height difference h1 between the center and the outer edge of the lower surface 22 of the top plate portion 11 is not particularly limited, but from the viewpoint of optimizing air bubble discharge, it is preferably about 1.6 mm. However, the lower surface 22 of the top plate portion 11 is not limited to an inclined surface, and may be a horizontal surface without any level difference.

In this embodiment, the upper surface 21 of the top plate portion 11 also has a concave shape at the center, and at least a part of the upper surface 21 has an inclined upper surface. In this embodiment, since the inclination of the inclined portion of the upper surface 21 substantially coincides with the inclination of the lower surface 22, the thickness of the top plate portion 11 can be made substantially equal from the center portion to the outer edge portion. By making the thickness of the top plate portion 11 approximately equal, sink marks are less likely to occur during injection molding and molding accuracy is improved. Therefore, the width of the slit 15 can be kept consistent, thereby achieving a high blocking function against blood clots and the like. It can also reduce the injection pressure during injection molding. If the injection pressure becomes high, burrs are likely to be generated on the thin ribs 13, and the burrs on the ribs 13 may cause hemolysis. However, the inclination of the upper surface 21 of the top plate portion may not be consistent with the inclination of the lower surface 22 . The upper surface 21 may be a horizontal surface without any height difference.

In this embodiment, the top plate opening 17 is formed in the top plate portion 11 and penetrates up and down. During pre-charging, air bubbles are also discharged from the top plate opening 17 to the outside of the filter. During use, blood not only flows into the filter 10 from the slit 15 but also flows into the filter 10 from the top plate opening 17 . This generates a downward flow on the lower side of the top plate portion 11 and can reduce stagnation on the lower side of the top plate portion 11 . The top plate opening 17 of this embodiment is formed in the radial direction and has a substantially rectangular shape with a radial length longer than a circumferential width. By forming such a shape, downward flow can be generated more easily. It should be noted that the shape of the opening surface of the top plate opening 17 is not limited to a substantially rectangular shape, and may be a substantially triangular or substantially elliptical shape in which the radial length is longer than the maximum value of the circumferential width.

Furthermore, three top plate openings 17 are formed radially from the center of the top plate portion 11 . By forming such a structure, it can be dispersed evenly, making retention less likely to occur. It should be noted that the number of the top plate openings 17 may be one, two, or four or more, and the top plate openings 17 are not limited to radial shapes, and may also be formed along the circumferential direction.

The top plate opening 17 is formed to gradually widen from the lower end toward the upper end, and the radially outer hole wall 17b has a steeper inclination than the radially inner hole wall 17a and becomes a substantially vertical surface. By forming such a shape, it is possible to prevent blood clots and the like from passing through, and at the same time, air bubbles can be easily discharged. Formation of the top plate opening 17 also becomes easy. It should be noted that the inclination of the radially inner hole wall 17a and the radially outer hole wall 17b may be the same, and the angle of inclination is not particularly limited. You may adopt a structure in which at least one of the radially inner hole wall 17a and the radially outer hole wall 17b is not inclined.

In this embodiment, the outer edge of the upper surface 21 of the top plate portion 11 is chamfered. The depression formed in the central part is also formed gently. The upper end of the hole wall of the top plate opening 17 is chamfered. Therefore, there are no acute-angled corners on the upper surface of the top plate portion 11 , and hemolysis caused by the corners can be suppressed.

The filter 10 of this embodiment is not particularly limited, and can be formed by injection molding polypropylene, polyethylene, or the like. Any mold can be used for molding. However, by using a mold having a plurality of gates on the lower ring 12 side for injection molding, injection molding can be reduced compared to the case of using a mold having a gate in the center of the top plate portion 11 . pressure. This can reduce burrs generated on the ribs 13 in particular.

Even a filter including only part of the structure of the ribs 13 , the intermediate ring 14 , and the top plate 11 included in the filter of this embodiment can reduce the retention of blood.

Figure 9 shows a drip chamber according to a second embodiment. As shown in FIG. 9 , the intravenous drip chamber according to the second embodiment includes a chamber body 200 and a filter 100 housed inside the chamber body 200 . The chamber main body 200 has a cylindrical part 205, an upper cover 203 attached to the upper part of the cylindrical part 205, and a lower cover 206 attached to the lower part. The upper cover 203 has a plurality of ports 231 for connecting hoses. The number and arrangement of the ports 231 provided on the upper cover 203 are not particularly limited. The port 231 may also be provided on the side of the upper cover 203 . The lower cover 206 is reduced in diameter downward, and a hose 302 is connected to the lower end. The filter 100 is embedded in the lower cover 206 . It should be noted that the structure of the chamber body 200 is not limited to this.

As shown in FIGS. 10 and 11 , the filter 100 has a filter holding part 101 and a mesh filter 102 held by the filter holding part 101 . The mesh filter 102 is formed in a cylindrical shape surrounding the filter holding portion 101 . The inner surface of the mesh filter 102 is in close contact with and fixed to the outer surface of the filter holding portion 101 . Compared with the case of arranging the mesh filter 102 in the filter holding part 101, by arranging the mesh filter 102 on the outer surface of the filter holding part 101, close fixation becomes very easy.

As shown in FIGS. 11 to 14 , the filter holding part 101 has a top plate part 111 , a lower ring 113 , and a support column 112 connecting the top plate part 111 and the lower ring 113 . In this embodiment, two pillars 112 are provided at positions facing each other across the center of the filter holding portion 101 . Therefore, the positions of the top plate portion 111 and the lower ring 113 can be firmly fixed, and the shape of the filter 100 can be stabilized. Since a large opening can be secured on the side surface of the filter holding part 101, retention can be made less likely to occur. However, the number of pillars 112 may be one, or more than three.

The pillars 112 do not project outward in the radial direction relative to the top plate portion 111 and the lower ring 113 , and the outer surfaces of the top plate portion 111 , the pillars 112 and the lower ring 113 are the same surface. Therefore, the mesh filter 102 is wound around the outside of the filter holding part 101 and the inner surface of the mesh filter 102 is in close contact with the outer surfaces of the top plate part 111, the pillar 112 and the lower ring 113, and is fixed to the The filter 100 can be easily formed on the outer surfaces of the top plate portion 111, the pillars 112, and the lower ring 113.

The upper end of the mesh filter 102 is fixed to the side surface of the top plate part 111 and the lower end is fixed to the side surface of the lower ring 113. The mesh filter 102 is supported by the pillars 112 in the vertical direction. Therefore, the mesh filter 102 is less likely to deform and can stably allow blood to pass through it. The length of the support 112 can be appropriately set according to the required blood flow rate, etc. However, in the case of a normal blood circuit filter, the length of the support 112 is preferably about 20 mm from the viewpoint of ensuring the opening. From the viewpoint of ensuring strength, the width of the pillar is preferably about 2.5 mm.

The method of fixing the mesh filter 102 closely to the filter holding part 101 may be welding, gluing, or the like. In the case of welding, the mesh filter 102 may be welded by pressing the jig from the outside while the mesh filter 102 is wound around the filter holding part 101 . In the case of fixing by welding, since the fused portion of the filter holding portion 101 and the mesh filter 102 are entangled with each other, the fixing method can be easily determined.

In this embodiment, the mesh filter 102 is fixed to the outer surface of the top plate portion 111 . Therefore, there is no need to provide a recess or the like for receiving the mesh filter 102 on the lower surface of the top plate portion 111. The top plate portion 111 is formed in a thick plate shape with the lower surface positioned highest at the outer edge. Therefore, there is no space above the upper end of the mesh filter 102 through which blood can pass, making it difficult for blood to accumulate. The outer diameter of the top plate 111 may be appropriately determined depending on the size of the chamber, required blood flow, etc., but in the case of a normal blood circuit filter, the outer diameter of the top plate 111 is preferably about 12 mm. Furthermore, from the viewpoint of easily fixing the mesh filter 102 to the outer surface, the thickness of the outer edge in the axial direction is preferably about 3 mm.

The top plate portion 111 is provided with a top plate opening 116 . By providing the top plate opening 116 in the top plate portion 111, air bubbles can be easily discharged during pre-charging. In this embodiment, the top plate opening 116 has a groove shape extending in the circumferential direction between the central portion 111 a and the outer edge portion 111 b. The central portion 111a and the outer edge portion 111b are connected together by spoke portions 111c provided every 90°, and the top plate opening 116 is divided into four parts.

As shown in FIG. 12 , in the present embodiment, the radial width D2 of the lower end of the top plate opening 116 is smaller than the radial width D1 of the upper end. The radial width D2 of the lower end is a width through which blood clots and the like cannot pass. The specific value of D2 can be determined taking various conditions into consideration, and can be set to about 0.3 mm, for example. By making the radial width D1 of the upper end portion larger than D2, blood clots and the like can be prevented from passing through, and air bubbles can be easily discharged during pre-charging. Formation of the top plate opening 116 also becomes easy. D1 is not particularly limited, and may be about 1 mm, for example. However, D1 and D2 can also be made equal.

In this embodiment, the hole wall 116b on the outer edge portion 111b side of the top plate opening 116 is a vertical surface, and the hole wall 116a on the central portion 111a side is inclined so as to be closer to the hole wall on the outer edge side as it goes downward. noodle. By making the hole wall 116b on the outer edge side a vertical surface, the radial thickness of the annular outer edge portion 111b outside the top plate opening 116 is equal, so deformation is less likely to occur during molding, and the sides of the top plate portion 111 can be made Smooth surface. Therefore, the mesh filter 102 can be easily welded to the side surface of the top plate portion 111 . However, as long as the top plate opening 116 has a radial width that cannot allow blood clots or the like to pass through, the hole wall 116b on the outer edge portion 111b side may be an inclined surface, or the hole wall 116b on the outer edge portion 111b side and the central portion 111a side may be. Both sides of the hole wall 116a are inclined surfaces.

In this embodiment, the top plate opening 116 is formed into a groove shape divided into four parts in the circumferential direction, but the number of divisions can be set arbitrarily. A plurality of radially extending grooves may also be arranged radially.

In this embodiment, a lower surface convex portion 117 is formed on the lower surface of the top plate portion 111 , which protrudes from the outer edge portion 111 b toward the center of the top plate portion 111 and whose protruding height gradually increases. The bubbles that have reached the lower surface of the top plate portion 111 move toward the top plate opening 116 along the lower surface convex portion 117 . Therefore, air bubbles can be more easily discharged during pre-charging. The protrusion height h1 of the lower surface convex portion 117 is not particularly limited, but from the viewpoint of good air bubble discharge, the protrusion height h1 is preferably about 1.6 mm. However, the lower surface convex portion 117 may or may not be provided as required.

In this embodiment, the recessed portion 111d is provided in the center portion of the upper surface of the top plate portion 111 . The recessed portion 111d is a trace of the gate during molding. However, by providing the recessed portion 111d on the upper surface corresponding to the lower surface convex portion 117, the effect of suppressing the thickness change of the central portion 111a and making molding easier can be obtained.

In this embodiment, the outer edge of the upper surface of the top plate portion 111 is chamfered. Furthermore, the upper end of the hole wall of the top plate opening 116 is chamfered. The recessed portion 111d is a shallow depression in the shape of a dish. Therefore, there are no acute-angled corners on the upper surface of the top plate portion 111, and hemolysis caused by the corners can be suppressed.

In this embodiment, the outer diameter of the top plate part 111 matches the outer diameter of the lower ring 113, and the filter 100 has a cylindrical shape with a constant outer diameter. In the case of a truncated cone-shaped filter in which the diameter of the lower part is larger than that of the upper part, the amount of blood passing through the mesh filter 102 increases toward the lower part, so blood may accumulate in the upper part of the filter. Since the filter 100 of this embodiment has a cylindrical shape, the amount of blood passing through the mesh filter is substantially constant, blood is less likely to remain in the filter, and the occurrence of coagulation can be suppressed. If the shape of the chamber body 200 is the same, a truncated cone-shaped filter is less likely to cause retention outside the filter. However, from the viewpoint of suppressing the occurrence of coagulation in the filter, which is a bigger problem, a cylindrical filter is preferred.

By making the outer diameter of the top plate portion 111 coincide with the outer diameter of the lower ring 113, the mesh filter 102 cut into a rectangular shape can be wound around the filter holding portion 101, so that the filter 100 can be formed very easily. The advantages.

In this embodiment, a flange portion 114 having an outer diameter larger than that of the lower ring 113 is provided at the lower end of the lower ring 113 . A notch 114 a is provided in the flange portion 114 at a position corresponding to the pillar 112 . By providing the notch 114a, the filter holding part 101 can be easily rotated by holding it with a clamp. When one side of the mesh filter 102 cut into a rectangular shape is placed at the position of one of the pillars 112 and the adjacent side is in contact with the flange part 114, and the filter holding part 101 is rotated, it can be easily The mesh filter 102 is neatly wound around the filter holder 101 .

In this embodiment, the flange portion 114 also functions as an attachment portion for attaching the filter 100 to the chamber body 200 . As shown in FIG. 9 , the filter 100 can be easily installed on the chamber body 200 by fitting the flange portion 114 into the recessed portion provided on the inner surface of the lower cover 206 . However, the method of fixing the filter 100 to the chamber body 200 is not limited to this method.

The outer diameter of the flange portion 114 is not particularly limited. However, from the viewpoint of making it easier to roll up the mesh filter 102 and to easily install it on the chamber body 200 , the outer diameter of the flange portion 114 is preferably larger than that of the lower ring 113 . The outer diameter is about 10% to 20% larger. The flange portion 114 only needs to be provided at the upper end of the lower ring 113 , but it is not necessarily required to be provided at the lower end of the lower ring 113 . The flange portion 114 may not be provided. It is also possible to provide the flange portion 114 without the notch 114a.

The mesh filter 102 can use a general mesh with a pore diameter of about 40 μm to 100 μm for removing foreign matter. However, a mesh made of a relatively hydrophilic material such as polyester is preferred. You can also use hydrophilic treated screens. The filter holding part 101 may be made of a material that can be fixed in close contact with the mesh filter 102 . When the polyester mesh filter is fixed by high-frequency welding, polypropylene that is easily welded is preferred.

The drip chamber of this embodiment can be connected to either the arterial side or the venous side of the blood circuit.

-Industrial applicability-

The filter for an intravenous drip chamber of the present disclosure is less likely to cause retention and can be used in an intravenous drip chamber of a blood circuit or the like.

10:Filter 11: Top plate part 12:Lower ring 13:ribs 13a: Peripheral part 13b: Inner peripheral part 14: middle ring 15: slit 16: Gap 17: Top plate opening 17a: Hole wall 17b: Hole wall 18: Inclined area 19:Space 21: Upper surface 22: Lower surface 100: filter 101: Filter holding part 102: Mesh filter 111: Top plate part 111a:Central Department 111b: outer edge part 111c: Spoke part 111d: concave part 112:Pillar 113:Lower ring 114:Flange part 114a: Gap 116: Top plate opening 116a: Hole wall 116b: Hole wall 117: Lower surface convex part 200: Chamber body 201:Tubular part 201a: Groove 203:Upper cover 205:Tubular part 206:Lower cover 231:port 301:Hose 302:Hose

FIG. 1 is a cross-sectional view showing the drip chamber according to the first embodiment. FIG. 2 is a side view showing the filter according to the first embodiment. FIG. 3 is a plan view showing the filter according to the first embodiment. 4 is a cross-sectional view showing the filter according to the first embodiment. FIG. 5 is an enlarged cross-sectional view of a rib. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3 . FIG. 7 is an enlarged cross-sectional view showing the fitting portion of the filter and the chamber body. FIG. 8 is an enlarged cross-sectional view showing the opening of the top plate. 9 is a cross-sectional view showing the drip chamber according to the second embodiment. Fig. 10 is a perspective view showing the filter according to the second embodiment. Fig. 11 is a perspective view showing a filter holding portion according to the second embodiment. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11 . FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 11 . FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 11 .

12:Lower ring

13:ribs

13a: Peripheral part

13b: Inner peripheral part

14: middle ring

15: slit

Claims (11)

A filter for an intravenous drip chamber, characterized in that it includes a top plate, a lower ring, a plurality of ribs, and an intermediate ring. The plurality of ribs connect the aforementioned top plate and the aforementioned lower ring, and a plurality of slits are formed between the plurality of ribs. slit, the aforementioned intermediate ring connects the aforementioned ribs to each other in the circumferential direction; The aforementioned rib has an outer peripheral portion and a triangular inner peripheral portion, and the angle formed by the direction in which the side surface of the aforementioned inner peripheral portion extends and the radial direction is greater than the angle formed by the direction in which the side surface of the aforementioned outer peripheral portion extends and the radial direction; The radial thickness of the intermediate ring is thinner than the radial thickness of the rib at a position where the intermediate ring is formed. A filter for an intravenous drip chamber, characterized in that it includes a top plate, a lower ring, and a plurality of ribs. The plurality of ribs connect the aforementioned top plate and the aforementioned lower ring, and a plurality of slits are formed between the plurality of ribs; The top plate portion has an inclined lower surface that goes downward toward the center portion and a top plate opening that penetrates up and down. The filter for an intravenous drip chamber according to Claim 2, wherein the top plate portion has an inclined upper surface that becomes lower toward the center. The filter for an intravenous drip chamber according to claim 3, wherein the top plate opening is formed in a radial direction and has a radial length that is longer than a circumferential width. A filter for an intravenous drip chamber, which includes a top plate, a lower ring, and a plurality of ribs. The plurality of ribs connect the aforementioned top plate and the aforementioned lower ring, and a plurality of slits are formed between the plurality of ribs; The aforementioned ribs have an inclined area at the lower end, and the radial thickness of the inclined area gradually decreases toward the downward side to form a space on the lower side. The filter for the drip chamber according to claim 5, further comprising an intermediate ring formed between the aforementioned top plate portion and the aforementioned lower portion ring; The outer peripheral surface of the rib has a step portion protruding radially outward at a position intersecting the intermediate ring. A filter for an intravenous drip chamber, characterized in that it includes a mesh filter and a filter holding part that holds the mesh filter in a cylindrical shape; The filter holding part has a top plate part, a lower ring, and a support part connecting the top plate part and the lower ring; The position of the lower surface of the aforementioned top plate portion is highest at the outer edge, and the aforementioned top plate portion has a top plate opening that penetrates up and down; The aforementioned top plate opening has a smaller minimum gap width at the lower end than at the upper end; The inner surface of the mesh filter is fixed against the outer surface of the filter holder. The filter for an infusion chamber according to claim 7, wherein a plurality of the top plate openings are formed on a circumference surrounding the center of the top plate, the hole wall on the outer edge side is a vertical surface, and the hole wall on the center side is a vertical surface. An inclined surface that is inclined closer to the hole wall on the outer edge side as it goes downward. The filter for an intravenous drip chamber according to claim 7, wherein the top plate portion has a lower surface convex portion protruding from a position of the top plate opening toward a center of the top plate portion, with a protruding height gradually increasing. The filter for an intravenous drip chamber according to Claim 7, wherein the outer diameter of the lower ring is consistent with the outer diameter of the top plate portion. The filter for an intravenous drip chamber according to claim 10, which has a flange portion protruding radially outward from the lower portion of the ring; The aforementioned flange portion has a notch portion on the outer peripheral surface; The notch portion is provided such that its circumferential position coincides with that of the pillar portion.