Medical liquid transmission chamber and tube set

Abstract

To reduce a case where liquid inside a housing flows back toward an upstream side at the time of pressurization operation of the housing.SOLUTION: A medical liquid transmission chamber 1 includes: an elastic housing 10 having an internal space 11; and a flexible sheet part 20 having a first surface and a second surface, and having an upstream side fixed to the housing 10 and a downstream side arranged in the internal space 11 of the housing 10. The sheet part 20 includes: a seal region 22 including a seal part 21 in which a first surface and a second surface overlap each other and both end portions of the first surface and the second surface in a width direction are joined to each other; and an unsealed region 23 formed in a downstream side end portion and in which both end portions of the first surface and the second surface in the width direction are not joined to each other. The sheet part 20 allows liquid transmitted from the upstream to the internal space 11 to pass but prevents passage of the liquid transmitted from the internal space 11 to the upstream.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a medical fluid delivery chamber and a tubing set, and more particularly to a medical fluid delivery chamber and a tubing set for rapid fluid delivery. [Background technology]

[0002] Generally, infusions and blood transfusions are performed by connecting an infusion (transfusion) set to a bag containing medicinal fluid or blood, and allowing the medicinal fluid (blood) to flow naturally. However, in emergencies such as major vascular surgery or hemorrhagic shock, blood may need to be transfused rapidly into the patient's body. In such cases, a hand pump can be used to perform a rapid transfusion. Rapid transfusion using a hand pump involves releasing the hand from pressing the hand pump, which causes the negative pressure inside the hand pump to flow blood into the hand pump from upstream, and then pressing the hand pump again to send the blood downstream. The transfusion is performed by repeating these steps.

[0003] An example of a transfusion system used for emergency transfusion is the rapid infusion kit disclosed in Patent Document 1. This rapid infusion kit is equipped with a pump unit in the infusion path that is driven by the application and release of external pressure, and this pump unit infuses the required amount of fluid at the required speed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Registered Utility Model No. 3005461 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even with the rapid infusion kit disclosed in Patent Document 1, since blood transfusion is performed by pressing the pump unit as described above, there is a problem in that the liquid stored in the pump unit flows back upstream. [Means for solving the problem]

[0006] The medical fluid delivery chamber of the present invention is a medical fluid delivery chamber that is provided midway along a flow path for delivering liquid from upstream to downstream, and comprises: a housing that is elastic and has an internal space for storing liquid; and a flexible sheet portion that has a first surface and a second surface, and is fixed to the housing on its upstream side and is located within the internal space on its downstream side. The sheet portion has a sealed area where the first surface and the second surface overlap and has a sealed area where both widthwise ends of the first surface and the second surface are joined, and an unsealed area formed at the downstream end where both widthwise ends of the first surface and the second surface are not joined. The sheet portion is characterized in that it allows liquid delivered from upstream to the internal space to pass through, while preventing liquid delivered from the internal space to pass upstream.

[0007] According to the above configuration, even if the housing is pressed from the outside and liquid in the internal space rises toward the sheet portion, the flexible sheet portion deforms freely within the internal space to absorb the pressure and allow it to flow away, preventing the gap between the first and second surfaces from easily opening. Meanwhile, because the upstream side of the sheet portion is fixed to the housing, liquid from upstream opens the overlapping sheets, allowing the liquid to pass into the internal space. Furthermore, the formation of an unsealed region at the downstream end makes the sheet portion relatively less rigid at the downstream end. This allows the tip of the sheet portion to bend more easily in response to external forces and more easily absorb and allow the pressure to flow away. Furthermore, when the sheet portion bends, the flow path of the sheet portion is partially blocked by the bending, making it more difficult for liquid to enter the inside of the sheet portion (between the first and second surfaces), effectively preventing backflow.

[0008] In the medical fluid delivery chamber according to the present invention, the sheet portion may have a bent portion that is formed to bend along the width direction of the sheet portion, and the angle may change in the vertical direction via the bent portion.

[0009] With this configuration, the flow path of the seat portion is easily blocked by the bent portion. Also, the opening edge of the seat portion is less likely to face the liquid surface, which reduces the possibility of an external force such as a rising liquid surface opening up the gap between the first and second surfaces, making it possible to more effectively prevent backflow.

[0010] In the medical fluid delivery chamber according to the present invention, the first surface of the seat portion may be configured to approach the inner wall of the internal space as it approaches the downstream side.

[0011] According to the above configuration, the end of the seat portion can be positioned higher, and the bending direction of the seat portion when the liquid level rises can be stabilized, making it possible to more effectively prevent backflow.

[0012] In the medical fluid delivery chamber according to the present invention, both widthwise ends of the seal area may be bent so as to be convex on one side in the direction in which the first surface and the second surface overlap.

[0013] According to the above configuration, if both widthwise ends of the sealed area are convex toward one side in the direction in which the first and second surfaces overlap, the rigidity of the sealed area in the sheet portion increases, while the rigidity of the unsealed area decreases relatively, making the unsealed area or the boundary between the unsealed area and the sealed area more likely to bend. This reduces the chance of the gap between the first and second surfaces opening, making it possible to more effectively prevent backflow.

[0014] In the medical fluid delivery chamber of the present invention, the housing has a flat upstream welded portion that closes the upstream opening of the internal space, and a flat downstream welded portion that closes the downstream opening of the internal space, and the welded surface of the upstream welded portion and the first and second surfaces of the sheet portion may intersect with the welded surface of the downstream welded portion.

[0015] With the above configuration, compared to when the welded surfaces are welded in the same direction, the housing becomes more three-dimensional, making it less likely to collapse, allowing for an increase in capacity, and making it easier to apply pressure to the housing. Furthermore, in order to efficiently compress the volume, it is expected that the pressure will be applied to a wider area on the lower side of the housing. In this case, however, because the pressure is applied in a direction opposite the surface of the sheet, external pressure from fingers is less likely to reach the side edges of the sheet, reducing the likelihood of the sheet opening due to the pressure application.

[0016] In the medical fluid delivery chamber of the present invention, the housing has a flat upstream weld that closes the upstream opening of the internal space, and the edge of the upstream weld that defines the boundary between the upstream weld and the internal space may form a V-shape that slopes toward the seat portion.

[0017] With this configuration, the area to be welded is increased, and the sheet portion can be more securely fixed to the housing, which prevents the sheet portion from coming off the housing even during rapid transfusion.

[0018] The tube set equipped with the medical fluid delivery chamber according to the present invention may be provided with a check valve at the downstream end of the housing or downstream of the housing to prevent backflow from the downstream side to the upstream side.

[0019] With this configuration, when the housing returns to its original shape due to elastic force after being pressurized, the amount of liquid flowing into the housing from the downstream side can be reduced, and the amount of liquid flowing into the housing from the upstream side can be increased, thereby increasing the amount of liquid delivered per unit time.

[0020] The medical fluid delivery chamber of the present invention is a medical fluid delivery chamber that is provided midway along a flow path for delivering liquid from upstream to downstream, and comprises: a housing that is elastic and has an internal space for storing liquid; and a flexible sheet portion that has a first surface and a second surface, and whose upstream side is fixed to the housing and whose downstream side is located within the internal space. The sheet portion has a seal portion where the first and second surfaces overlap and both widthwise ends of the first and second surfaces are joined, allowing liquid delivered from upstream to the internal space to pass through while preventing liquid delivered from the internal space to pass upstream. The housing comprises a flat upstream welded portion that closes the upstream opening of the internal space and a flat downstream welded portion that closes the downstream opening of the internal space, and the welded surface of the upstream welded portion and the first and second surfaces of the sheet portion intersect with the welded surface of the downstream welded portion.

[0021] According to the above configuration, even if the housing is pressed from the outside and the liquid in the internal space rises, the lower end of the flexible sheet portion deforms freely within the internal space, making it difficult for a force to separate the first and second surfaces, and preventing the sheet portion from opening easily. Furthermore, compared to when the welded surfaces are welded in the same direction, the housing has a more three-dimensional shape, making it less likely to collapse unintentionally, allowing for an increased capacity, and facilitating pressure application to the housing. Furthermore, in order to efficiently and significantly change the volume of the internal space, pressure is expected to be applied to a wider area on the lower side of the housing (i.e., pressing the lower side of the housing along the width direction of the downstream welded portion). In this case, the pressing direction is opposite the first and second surfaces of the sheet portion, making it difficult for external pressure from fingers to reach the side edges of the sheet portion, reducing the likelihood of the sheet portion opening due to pressure application.

[0022] The tube set according to the present invention includes a medical fluid delivery chamber provided midway through a flow path for delivering a liquid from upstream to downstream, a first tube on the upstream side that constitutes the flow path, and a second tube on the downstream side that constitutes the flow path. The medical fluid delivery chamber includes a housing located between the first and second tubes, having elasticity and an internal space for storing a liquid. The tube set further includes a flexible sheet member having a first surface and a second surface, with its upstream side fixed to the housing and its downstream side disposed in the internal space of the housing. The sheet member has a sealing region where the first and second surfaces overlap and where both widthwise ends of the first and second surfaces are joined. The sheet member allows the liquid delivered from the first tube to the internal space to pass through while preventing the liquid delivered from the internal space to the first tube from passing through. The tube set further includes a check valve at the downstream end of the housing or downstream of the housing to prevent backflow from the downstream side to the upstream side.

[0023] According to the above configuration, even if the housing is pressed from the outside and the liquid in the internal space rises, the lower end of the flexible sheet portion on the liquid transfer path between the first tube and the housing is free to deform within the internal space, preventing the gap between the first and second surfaces from easily opening. Furthermore, the check valve can restrict the amount of liquid flowing into the housing from the second tube when the housing returns to its original shape due to its elastic force after being pressurized, thereby increasing the amount of liquid flowing into the housing from the first tube. This allows for an increase in the amount of liquid transferred per unit time. [Effects of the Invention]

[0024] The medical fluid delivery chamber and tube set according to the present invention can reduce the occurrence of a situation in which the liquid in the housing flows back upstream when the housing is pressurized. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective view of a medical fluid delivery chamber according to the present embodiment. [Figure 2]FIG. 2 is a front view of the medical fluid delivery chamber according to the present embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing the cross section AA in FIG. 2. [Figure 4] FIG. 2 is a plan view of the medical fluid delivery chamber according to the present embodiment. [Figure 5] FIG. 3 is an enlarged view of part B in FIG. 2. [Figure 6] FIG. 2 is a schematic diagram showing a tube set according to the present embodiment. [Figure 7] 1 is a schematic diagram showing a check valve installed in a tube according to an embodiment of the present invention. FIG. [Figure 8] FIG. 10 is a cross-sectional view showing a first modified example of the seat portion of the medical fluid delivery chamber. [Figure 9] FIG. 10 is a cross-sectional view showing a second modified example of the seat portion of the medical fluid delivery chamber. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments of a medical fluid delivery chamber and a tubing set according to the present invention will be described in detail with reference to the drawings. The embodiments described below are merely examples, and the present invention is not limited to the following embodiments. Furthermore, the present invention also includes forms obtained by selectively combining multiple embodiments and modified examples described below.

[0027] The medical fluid-feeding chamber 1 according to this embodiment will be described in detail with reference to Figures 1 to 4. Figure 1 is a perspective view showing the medical fluid-feeding chamber 1. Figure 2 is a front view of the medical fluid-feeding chamber 1. Figure 3 is a cross-sectional view showing the AA cross section of Figure 2. Figures 1 to 3 show a state in which a first tube 30 and a second tube 31 are connected to the medical fluid-feeding chamber 1.

[0028] The medical fluid supply chamber 1 can be applied to, for example, rapid blood transfusion and rapid infusion. As will be described in detail later, in rapid blood transfusion, a first tube 30 connected to the medical fluid supply chamber 1 is connected to a blood bag (not shown) filled with blood. A blood transfusion path is formed by connecting a second tube 31 connected to the medical fluid supply chamber 1 to a patient. Furthermore, blood is transfused from the blood bag to the patient by applying or releasing external pressure to the medical fluid supply chamber 1. Hereinafter, the side of the medical fluid supply chamber 1 connected to the blood bag will be referred to as the upstream side, and the side connected to the patient will be referred to as the downstream side. In this embodiment, a case of rapid blood transfusion will be described as an example.

[0029] 1 to 3, the medical fluid-feeding chamber 1 includes a housing 10 having elasticity and an internal space 11 for storing a liquid inside a first tube 30 and a second tube 31. The medical fluid-feeding chamber 1 is provided midway through a flow path for feeding a liquid from upstream to downstream, with the first tube 30 connected to the upstream side of the housing 10 and the second tube 31 connected to the downstream side of the housing 10. The first tube 30 constitutes the flow path on the upstream side of the medical fluid-feeding chamber 1, and the second tube 31 constitutes the flow path on the downstream side of the medical fluid-feeding chamber 1.

[0030] The medical fluid-feeding chamber 1 further includes a flexible sheet portion 20 that allows blood delivered from upstream into the internal space 11 of the housing 10 to pass through while preventing blood delivered from the internal space 11 to the upstream side from passing through. The sheet portion 20 has a first surface 20a and a second surface 20b (see FIG. 3 ), and its upstream side is fixed to the upper end of the housing 10 and its downstream side is disposed within the internal space 11 of the housing 10. The sheet portion 20 includes a sealed region 22 including a sealed portion 21 where the first surface 20a and the second surface 20b overlap and both widthwise ends of the first surface 20a and the second surface 20b are joined, and an unsealed region 23 formed at the downstream end where both widthwise ends of the first surface 20a and the second surface 20b are not joined. As will be described in detail later, the housing 10 and the sheet portion 20 are formed of a flexible resin. An example of a suitable resin is polyvinyl chloride (PVC).

[0031] The housing 10 forms the exterior of the medical fluid delivery chamber 1. As described above, the housing 10 is made of an elastic material. A first tube 30 constituting a flow path is connected to the upper end of the housing 10, and a second tube 31 constituting a flow path is connected to the lower end. In this case, the upper and lower ends may be welded while the tubes are sandwiched between them. The housing 10 has a flat upstream weld portion 12 that closes the upstream opening of the internal space 11, and a flat downstream weld portion 13 that closes the downstream opening of the internal space 11. The welding method is not particularly limited and may be heat welding, high-frequency welding, solvent welding, or the like.

[0032] The upstream weld 12 has a flat surface and is welded to prevent an upstream opening of the internal space 11. The upstream weld 12 secures the sheet portion 20 and the first tube 30 to the housing 10. The upstream weld 12 may be welded by clamping the upstream end of the sheet portion 20 with the first tube 30 inserted into the upstream end of the sheet portion 20. This allows the process of securing the sheet portion 20 to the housing 10 and the process of forming the upstream weld 12 to be performed simultaneously, thereby reducing the number of processes. The first tube 30 and the internal space 11 of the housing 10 are in communication with each other via the sheet portion 20, allowing liquid to move from the first tube 30 to the internal space 11 via the sheet portion 20. The flat surface of the upstream weld 12 is formed to be parallel to the first surface 20a and the second surface 20b of the sheet portion 20.

[0033] 2, the upstream welded portion 12 has an edge that defines the boundary between the upstream welded portion 12 and the internal space 11, and the edge of the upstream welded portion 12 is inclined toward the first tube 30 (the seat portion 20 side), forming a V-shape. This increases the area to which the seat portion 20 is welded, and enables the seat portion 20 to be more securely fixed to the housing 10. As a result, the seat portion 20 can be prevented from coming off the housing 10 even during rapid transfusion.

[0034] Like the upstream welded portion 12, the downstream welded portion 13 also has a flat surface and is welded so as to block the downstream opening of the internal space 11. The downstream welded portion 13 may be welded while sandwiching the second tube 31. As described above, the internal space 11 is formed by closing the upstream and downstream openings of the housing 10 with the welded portions. This allows the first tube 30 and the second tube 31 to communicate with each other via the seat portion 20 and the internal space 11.

[0035] 3, the downstream weld 13 may have an inclined V-shape in which the edge of the downstream weld 13 that defines the boundary between the downstream weld 13 and the internal space 11 is inclined toward the second tube 31. This allows the liquid in the internal space 11 to flow efficiently into the second tube 31.

[0036] 4 is a plan view of the medical fluid supply chamber 1, showing the state in which the first tube 30 is connected. As shown in FIG. 4, in the plan view of the medical fluid supply chamber 1, the welded surface of the upstream welded portion 12 intersects with the welded surface of the downstream welded portion 13. Furthermore, the first surface 20a and the second surface 20b of the sheet portion 20 also intersect with the welded surface of the downstream welded portion 13. This makes the housing 10 more three-dimensional than when the welded surfaces of both welded portions are welded in the same direction, making the housing 10 less likely to collapse, allowing for an increased capacity, and making it easier to apply pressure to the housing 10.

[0037] In the example shown in FIG. 4 , the angle between the welded surface of the upstream welded portion 12 and the welded surface of the downstream welded portion 13 is approximately 90°. When this angle is approximately 90°, i.e., when the welded surfaces are approximately perpendicular to each other in a plan view of the medical fluid delivery chamber 1, the above-mentioned effect becomes more pronounced. In this case, the lower side of the housing 10 expands and becomes wider. When pressurizing the housing 10, it is assumed that the lower side of the expanded housing 11 is pressed in the direction of the extension of the downstream welded portion 13 to efficiently change the volume of the internal space 11. In this case, the pressing direction is opposite the first surface 20a and the second surface 20b of the sheet portion 20. As a result, external pressure from fingers is less likely to reach the side edges of the sheet portion 20, reducing the risk of the sheet portion 20 opening due to the pressurizing operation and improving the effectiveness of preventing backflow of blood.

[0038] The seat portion 20 will be described in detail below with further reference to Figures 2 and 5. Figure 5 is an enlarged view of part B in Figure 3.

[0039] As shown in FIG. 2, the lower end of the sheet portion 20 is located above the longitudinal center of the internal space 11 of the housing 10, and the longitudinal length L20 of the sheet portion 20 within the internal space 11 of the housing 10 may be 10% to 50% of the longitudinal length L11 of the internal space 11. Alternatively, it may be 15% to 45%, and preferably 20% to 40%. An example of the longitudinal length L20 of the sheet portion 20 within the internal space 11 of the housing 10 is 30% of the longitudinal length L11 of the internal space 11. From the viewpoint of both achieving a stable supply of blood from the upstream side and preventing backflow of blood, the longitudinal length L23 of the unsealed region 23 is preferably 50% or less, more preferably 40% or less, of the longitudinal length L22 of the sealed region 22 within the internal space 11, for example, 20% to 40%.

[0040] The seat portion 20 may be fixed while being clamped to the upper end of the housing 10 with the first tube 30 inserted into the upstream end. As a result, the seat portion 20 disposed in the internal space 11 may have a gap between the first surface and the second surface that gradually decreases from the upstream end where the first tube 30 is inserted toward the downstream end, and the lower sides may overlap.

[0041] The joining of both widthwise ends of the first surface 20a and the second surface 20b is performed by, for example, welding. Note that the welding method is not particularly limited. In this embodiment, the case where the joining of the first surface 20a and the second surface 20b is performed by welding will be described as an example.

[0042] Since only both widthwise ends of the sheet portion 20 are welded, the central portion in the widthwise direction is permeable to liquid. The shape of the sheet portion 20 may be rectangular, or may be a trapezoid whose width increases toward the downstream side. On the other hand, the sheet portion 20 may have a shape whose width decreases toward the downstream side.

[0043] The sealed portions 21 are formed at both widthwise ends of the sheet portion 20. The sealed portions 21 are formed by welding both widthwise ends of the first surface 20a and the second surface 20b while the first surface 20a and the second surface 20b are overlapping each other. The sheet portion 20 may be formed, for example, by overlapping two sheets and welding both widthwise ends of the two sheets.

[0044] The sealed portion 21 welds both widthwise ends of the sheet portion 20 downward from the upstream end. The longitudinal length of the sealed portion 21 may be determined based on the longitudinal length of the sheet portion 20 and the length of the unsealed region 23, but preferably extends longer than the widthwise length of the sheet portion 20. For example, the longitudinal length is preferably at least twice the widthwise length. The widthwise length of the sealed portion 21 is not particularly limited and may be set appropriately. For example, the widthwise length of the sealed portion 21 may be set so that the opening at the upstream end of the sheet portion 20 has a diameter larger than the outer diameter of the first tube 30. The widthwise length of the sealed portion 21 is, for example, 2 mm.

[0045] In the example shown in Figure 2, the seal portion 21 is formed to be rectangular, but the seal portion 21 may be wider or narrower toward the downstream end.

[0046] The sheet portion 20 has unsealed regions 23 at both widthwise ends thereof, each of which is not welded for a predetermined length from the downstream end. The predetermined length may be 4 mm to 16 mm, or 6 mm to 14 mm. It is also preferable that the predetermined length is 8 mm to 12 mm. An example of the predetermined length is 10 mm. That is, an example of the length of the unsealed region 23 is 10 mm. The length of the unsealed region 23 is set appropriately depending on the intended use, size, etc. of the medical fluid delivery chamber 1.

[0047] The sheet portion 20 functions as a backflow prevention valve in the medical fluid supply chamber 1. As will be described in detail later, when rapid transfusion is performed, fluid is supplied from upstream to downstream by squeezing and releasing the housing 10 of the medical fluid supply chamber 1. When the housing 10 is squeezing, the internal pressure increases, causing the liquid in the internal space 11 to move in the reverse direction. However, even if the housing 10 is pressed from the outside and the liquid in the internal space 11 rises upward, the lower side (e.g., the unsealed region 23) of the flexible sheet portion 20 on the fluid supply path between the first tube 30 and the housing 10 freely deforms within the internal space 11, preventing the gap between the first surface 20a and the second surface 20b from easily opening. This prevents backflow of the liquid in the internal space 11 and prevents the liquid being supplied from the housing 10 to the first tube 30 from passing through. Furthermore, by forming the unsealed region 23 at the downstream end, the downstream end has a lower rigidity than the sealed region 22, making it easier to release external forces. Also, the unsealed region 23 or the boundary between the unsealed region 23 and the sealed region 22 is more likely to bend, making it more difficult for liquid to penetrate between the first surface 20a and the second surface 20b.

[0048] Furthermore, in the sealed portion 21, the first surface 20a and the second surface 20b may not completely overlap (they may generally overlap, but with a small gap) due to the adhesive or a welded portion being located inside the sealed region 22 or distortion caused by the application of heat during welding. By forming the unsealed region 23 in addition to the sealed region 22, even if a small hole is formed due to distortion or other factors that cause a non-overlapping portion in the width direction of the downstream end of the sealed region 22, the presence of the sheet portion 20 that forms the unsealed region 23 makes it difficult for liquid to penetrate. Furthermore, the sheet portion 20 is prone to bending in the unsealed region 23 or at the boundary between the unsealed region 23 and the sealed region 22. This bending can block the flow path or cause the opening to be oriented in a direction that does not face the liquid surface, making backflow less likely than when the sealed region 22 is formed all the way to the bottom end of the sheet portion 20.

[0049] As shown in FIG. 5, the sheet portion 20 may have a bent portion 24 that is bent along the width direction of the sheet portion 20. The angle of the sheet portion 20 changes in the vertical direction via the bent portion 24. The bent portion 24 may be bent by applying pressure to the sheet portion 20 in a folded state. This makes it less likely that the open end of the sheet portion 20 will face the liquid surface, reducing the likelihood of the first surface 20a and the second surface 20b opening when blood rises, thereby more effectively preventing backflow of blood. Furthermore, compared to when the bent portion 24 is not provided, the sheet portion 20 is more easily deformed at the bent portion 24, and therefore the first surface 20a and the second surface 20b do not open as easily.

[0050] The bent portion 24 may be provided in the sealed region 22 or in the unsealed region 23, but is preferably formed at the boundary between the sealed region 22 and the unsealed region 23. The boundary between the sealed region 22 and the unsealed region 23 is a portion where the difference in rigidity in the longitudinal direction of the sheet portion 20 becomes large, so by forming the bent portion 24 at the boundary between the sealed region 22 and the unsealed region 23, the sheet portion 20 becomes easier to bend at the bent portion 24. As a result, the above-mentioned effect becomes more pronounced.

[0051] FIG. 5 illustrates an imaginary line α along the length of the housing 20, i.e., along the axial direction of the cylindrical housing 10, and an imaginary line β parallel to the imaginary line α. The upstream portion of the seat portion 20 from the bend 24 extends substantially parallel to the imaginary line α, while the downstream portion extends in a direction inclined at an angle θ1 with respect to the imaginary line α. That is, the seat portion 20 is bent at the bend 24 so that the angles of the upstream and downstream portions with respect to the imaginary line α (the length direction of the housing 20) change. Note that the upstream portion of the bend 24 may also be inclined with respect to the imaginary line α, but it is preferable that it bend in the same direction as the downstream portion. In this way, the entire seat portion 20 is inclined more perpendicularly to the direction of fluid flow, making it more difficult for the flow path of the seat portion 20 to open.

[0052] The angle θ1 is preferably larger than the angle θ2 of the inner wall of the housing 10 relative to the imaginary line β at the same position as the bent portion 24. Here, the same position as the bent portion 24 means the position where the length from the upper end of the internal space 11 along the longitudinal direction of the housing 10 is the same as that of the bent portion 24. The housing 10 gradually bulges downward, and its inner wall is inclined at an angle θ2 relative to the imaginary line β (the longitudinal direction of the housing 20). The angle θ2 is, for example, 10° or more and 20° or less. From the viewpoint of preventing backflow of blood, the angle θ1 of the seat portion 20 is preferably large, for example, 25° or more. On the other hand, if the angle θ1 is too large and the open end of the seat portion 20 comes into contact with the internal wall of the housing 10, it is considered that the flow of blood from the first tube 30 to the internal space 11 will be impaired. Therefore, the angle θ1 is preferably 60° or less.

[0053] As described above, the medical fluid delivery chamber 1 having the above-described configuration includes the sheet portion 20 having the sealed area 22 and the unsealed area 23 within the housing 10, and the sheet portion 20 has a backflow prevention function. Even if the housing 10 is pressed from the outside and the liquid within the internal space 11 rises upward, the lower side of the flexible sheet portion 20 on the liquid delivery path between the first tube 30 and the housing 10 is free to deform within the internal space 11, so the gap between the first surface 20a and the second surface 20b does not easily open. This makes it possible to prevent backflow of the liquid within the internal space 11.

[0054] A tube set 100 using the medical fluid delivery chamber 1 according to this embodiment will be described in detail with reference to Figures 6 and 7. Figure 6 is a schematic diagram showing the tube set 100 according to this embodiment. Figure 7 is a schematic diagram showing a check valve 40 installed in the tube according to this embodiment.

[0055] The tube set 100 shown in FIG. 6 connects a blood bag (not shown) on the upstream side to a patient on the downstream side, forming a blood transfusion route and performing blood transfusion. When performing rapid transfusion, the tube set 100 can perform rapid transfusion from the blood bag by applying and releasing external pressure to the housing 10 of the medical fluid supply chamber 1. Applying external pressure causes blood to be sent downstream from the medical fluid supply chamber 1. Meanwhile, releasing external pressure causes blood to flow from the upstream blood bag into the medical fluid supply chamber 1 and accumulate there. Repeating these operations allows the blood in the blood bag to be sent into the patient's body. The application and release of external pressure may also be performed manually. That is, rapid transfusion may be performed by manually squeezing and releasing the medical fluid supply chamber 1. This facilitates transfusion at the required speed and in the required amount.

[0056] The vial needle 50 is located at the upstream tip of the tubing set 100. The vial needle 50 has a straight rod shape with a sharp tip. By piercing the blood bag with the vial needle 50, blood is sent from the blood bag into the tube. If a blood transfusion is required quickly, more blood can be sent downstream by piercing the blood bag with two vial needles 50.

[0057] The filtering drip tube 60 is equipped with a filter to remove impurities such as clots from the blood bag. The roller clamp 70 adjusts the flow rate by compressing the tube by moving the roller. When performing rapid transfusion, the roller clamp 70 is not used to adjust the blood flow rate, and the roller clamp 70 is always open to allow the maximum amount of blood to be delivered. The connector 80 is located at the downstream tip of the tubing set 100 and is connected to a venous needle. The venous needle is inserted into the patient to connect the upstream blood bag to the patient.

[0058] Tube set 100 may include a check valve 40 that prevents backflow from the downstream side to the upstream side at the downstream end of housing 10 or downstream of housing 10. Check valve 40 may be installed in second tube 31, for example, as shown in FIGS. 6 and 7.

[0059] The check valve 40 is, for example, a duckbill valve. A duckbill valve is flexible and opens under the pressure of the liquid sent from the upstream side, and in the event of a backflow, closes under pressure from the downstream side, thereby preventing backflow. The check valve 40 may be provided on at least one of the downstream end of the housing 10 and the second tube 31, or multiple check valves 40 may be provided.

[0060] In detail, as shown in FIG. 7(A), the duckbill valve has a valve at its tip closed when there is no pressure from the liquid upstream. Furthermore, during backflow, the valve is closed by pressure from the downstream side, preventing backflow. Meanwhile, as shown in FIG. 7(B), the valve at the tip is opened by the pressure of the liquid delivered from the upstream side, allowing the liquid in the tube to move from upstream to downstream. Furthermore, the check valve 40 installed in the tube of the tube set 100 is not limited to a duckbill valve and may be appropriately configured depending on the intended use, etc. The check valve 40 may be, for example, an umbrella valve, a ball valve, a disc valve, or the like.

[0061] By providing the check valve 40, the tube set 100 can suppress the amount of liquid that flows into the housing 10 from the second tube 31 when the housing 10 returns to its original shape due to its elastic force after being pressurized, and can increase the amount of liquid that flows into the housing from the first tube 30. This makes it possible to increase the amount of liquid delivered per unit time.

[0062] When rapid transfusion is required, the tube set 100 of this embodiment performs rapid transfusion by applying and releasing external pressure to the medical fluid supply chamber 1. However, when rapid transfusion is not required, applying and releasing external pressure to the medical fluid supply chamber 1 is not necessary. That is, a transfusion set including the tube set 100 may be connected to a blood bag, and transfusion may be performed by gravity. This allows for normal transfusion by gravity flow of blood. Furthermore, the tube set 100 of this embodiment can be used even when a transfusion pump is used.

[0063] As described above, in the tube set 100 including the medical fluid delivery chamber 1 having the above configuration, by providing the check valve 40 on at least one of the downstream end of the housing 10 and the second tube 31, the amount of liquid flowing into the housing 10 from the second tube 31 when the housing 10 returns to its initial shape due to elastic force after being pressurized can be reduced, and the amount of liquid flowing into the housing 10 from the first tube 30 can be increased. This makes it possible to increase the amount of liquid delivered per hour.

[0064] The above-described embodiment may be modified as appropriate without departing from the scope of the present invention. For example, in the above-described embodiment, the sheet portion 20 includes a bent portion 24 that bends along the width direction. However, as shown in FIG. 8 , the sheet portion 20 may have a first surface 20a of the bent portion 24 that approaches the inner wall of the internal space 11 as it approaches the downstream side. In the example shown in FIG. 8 , the sheet portion 20 is gently curved overall, and a bend starting point 25, which serves as the starting point of the bend, is formed near the upstream welded portion 12 in the sealing area 22. In this case, the lower end of the sheet portion 20 can be positioned higher, and the bending direction of the sheet portion 20 when the liquid level rises can be stabilized, enabling more effective backflow prevention. Alternatively, the sheet portion 20 may be curved to approach the inner wall of the internal space 11 as it approaches the downstream side and include a bent portion 24.

[0065] 9, both widthwise ends of the sealed region 22 of the sheet portion 20 may be folded so as to be convex toward one side of the overlapping direction of the first surface 20a and the second surface 20b. In the example shown in FIG. 9, the sheet portion 20 is folded so that the sealed regions 21 are convex in the same direction at the boundary between the sealed region 21 and the unsealed region in a widthwise cross section of the sheet region 22. This may be achieved by thermally shrinking the sheet portion 20 due to heat generated by welding when forming the sealed regions 21. As a result, the rigidity of the sealed region 22 in the sheet portion 20 is improved and the rigidity of the unsealed region 23 is relatively reduced, making the boundary between the sealed region 22 and the unsealed region 23 more likely to deform and release external forces. In particular, the sheet portion 20 deforms and bends in the direction that the sealed region 21 is convex due to the force of the liquid in the internal space 11 attempting to flow back, effectively reducing the occurrence of a gap between the first surface 20a and the second surface 20b, thereby preventing backflow of blood.

[0066] Furthermore, in the above embodiment, an example was given of a form in which the first tube 30 is connected to the housing 10 of the medical fluid delivery chamber 1, but another example of a tube set in the embodiment may be a form in which a tubular member capable of storing a predetermined amount of liquid is connected to the upstream end of the housing 10, and the first tube 30 is connected to the tubular member.

[0067] Furthermore, it is preferable that the seat portion have an unsealed area, but if the welded surface of the upstream welded portion and the first and second surfaces of the seat portion intersect with the welded surface of the downstream welded portion, or if the medical fluid delivery chamber is provided with a check valve that prevents backflow from the downstream side to the upstream side at the downstream end of the housing or downstream of the housing, it is possible, for example, to omit the unsealed area and make the entire seal portion the sealed area. In this case, even if there is no unsealed area in the seat portion, the presence of the seat portion can reduce the possibility of liquid in the housing backflowing upstream when the housing is pressurized. [Explanation of symbols]

[0068] 1 medical fluid delivery chamber, 10 housing, 11 internal space, 12 upstream welding portion, 13 downstream welding portion, 20 seat portion, 21 sealing portion, 22 sealing area, 23 unsealed area, 24 bending portion, 30 first tube, 31 second tube, 40 check valve, 50 bottle needle, 60 filtration drip tube, 70 roller clamp, 80 connector, 100 tube set

Claims

1. A medical fluid delivery chamber provided in the middle of a flow path for delivering a liquid from upstream to downstream, a housing having an elastic force and an internal space for storing a liquid therein; a flexible sheet portion having a first surface and a second surface, the sheet portion having an upstream side fixed to the housing and a downstream side disposed within the internal space; Equipped with the sheet portion has a sealed region where the first surface and the second surface overlap and where both widthwise end portions of the first surface and the second surface are joined together, and an unsealed region formed at a downstream end portion and where both widthwise end portions of the first surface and the second surface are not joined together, The medical fluid delivery chamber, wherein the sheet portion allows passage of liquid delivered from the upstream side to the internal space, while preventing passage of liquid delivered from the internal space to the upstream side.

2. 2. The medical fluid delivery chamber according to claim 1, wherein the sheet portion has a bent portion that is bent along the width direction of the sheet portion, and the angle changes in the vertical direction via the bent portion.

3. The medical fluid delivery chamber according to claim 1 , wherein the first surface of the seat portion generally approaches the inner wall of the internal space as it moves downstream.

4. 2. The medical fluid delivery chamber according to claim 1, wherein both widthwise ends of the sealing area are bent so as to be convex on one side in a direction in which the first surface and the second surface overlap.

5. The housing includes: a flat upstream weld portion that closes an upstream opening of the internal space; a flat downstream weld portion that closes a downstream opening of the internal space; Equipped with The medical fluid delivery chamber according to claim 1 , wherein the welded surface of the upstream welded portion and the first and second surfaces of the seat portion intersect with the welded surface of the downstream welded portion.

6. the housing includes a flat upstream weld portion that closes an upstream opening of the internal space, The medical fluid delivery chamber according to claim 1 , wherein an edge of the upstream welded portion that defines the boundary between the upstream welded portion and the internal space forms a V-shape that slopes toward the seat portion.

7. A tube set including the medical fluid delivery chamber according to any one of claims 1 to 6, A tube set comprising a check valve at the downstream end of the housing or downstream of the housing, for preventing backflow from the downstream side to the upstream side.

8. A medical fluid delivery chamber provided in the middle of a flow path for delivering a liquid from upstream to downstream, a housing having an elastic force and an internal space for storing a liquid therein; a flexible sheet member having a first surface and a second surface, the sheet member having an upstream side fixed to the housing and a downstream side disposed within the internal space; Equipped with the sheet portion has a seal region where the first surface and the second surface overlap each other and both widthwise end portions of the first surface and the second surface are joined together, the sheet portion allows a liquid sent from the upstream side to the internal space to pass through, while preventing a liquid sent from the internal space to the upstream side from passing through; The housing includes: a flat upstream weld portion that closes an upstream opening of the internal space; a flat downstream weld portion that closes a downstream opening of the internal space; Equipped with a welding surface of the upstream welding portion and the first and second surfaces of the seat portion intersect with the welding surface of the downstream welding portion.

9. A tube set including a medical fluid delivery chamber provided midway through a flow path for delivering a liquid from upstream to downstream, a first tube on the upstream side constituting the flow path, and a second tube on the downstream side constituting the flow path, The medical fluid delivery chamber comprises: a housing positioned between the first tube and the second tube, the housing having elasticity and an internal space for storing a liquid; a flexible sheet member having a first surface and a second surface, the sheet member having an upstream side fixed to the housing and a downstream side disposed within the internal space; Equipped with the sheet portion has a seal region where the first surface and the second surface overlap each other and both widthwise end portions of the first surface and the second surface are joined together, the sheet portion allows passage of liquid delivered from the first tube to the internal space, while preventing passage of liquid delivered from the internal space to the first tube; A tube set comprising a check valve at the downstream end of the housing or downstream of the housing, for preventing backflow from the downstream side to the upstream side.

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