Hemostatic valve-attached connector

Abstract

Provided is a hemostatic valve-attached connector having a novel structure with which it is possible to reduce the amount of air left remaining in a tube lumen and an inner passage of the hemostatic valve-attached connector.　A hemostatic valve-attached connector 10 in which an internal flow passage 42, in which the distal end side communicates with a blood vessel via a tube 14, is blocked by a hemostatic valve 38, and the hemostatic valve 38 is switched to a communicating state by connecting an external connector 80 from the base end side, is provided with an air bleeding passage 70, which communicates the internal flow passage 42 with an external space and is provided open in the internal flow passage 42 closer to the distal end side than the hemostatic valve 38, and an air permeable filter 72, which is provided along the path of the air bleeding passage 70 and allows the passage of air and restricts the passage of blood, wherein the amount of air that is discharged to the outside of the internal flow passage 42 when an air pressure of 20 kPa is applied from the distal end side of the internal flow passage 42 in a state in which the hemostatic valve 38 is closed is at most 150 mL / min.

Description

Connector with hemostasis valve

[0001] The present invention relates to a connector with a hemostatic valve, which is a connector to be attached to, for example, a tube or needle assembly, and which is equipped with a hemostatic valve that can switch between restricting and allowing the passage of blood flowing in from the tip side.

[0002] As disclosed in Japanese Patent Laid-Open Publication No. 2000-342687 (Patent Document 1), for example, a connector is known that is provided at the base end of a long tube connected to a hollow needle whose tip is inserted into a blood vessel. The connector constitutes a connection mechanism for connecting to an external connector such as a syringe or a blood circuit.

[0003] Also known is a connector with a hemostatic valve that prevents blood from leaking when a hollow needle is inserted into a blood vessel. As described in, for example, Japanese Utility Model Laid-Open Publication No. 4-103149 (Patent Document 2), the connector with a hemostatic valve has an internal flow path that is blocked by a hemostatic valve. When an external connector is connected to the connector with a hemostatic valve from its base end, the hemostatic valve is switched to a communicating state.

[0004] Japanese Patent Application Laid-Open No. 2000-342687 Japanese Utility Model Application Laid-Open No. 4-103149

[0005] It is desirable that the internal flow path of a hemostatic valve-equipped connector connected to a blood vessel be filled with blood by venting air to the outside before connecting an external connector. Therefore, the hemostatic valve-equipped connector described in Patent Document 2 has an air vent passage formed therein, and a filter is installed in the passage. This filter allows gas to pass through but limits the passage of liquid, preventing blood leakage while allowing air to be vented from the internal flow path, thereby allowing the internal flow path of the hemostatic valve-equipped connector to be filled with blood flowing in from the distal end.

[0006] However, when the applicant adopted an existing connector with a hemostatic valve for an indwelling needle having a tube such as that disclosed in Patent Document 1, it was confirmed that air was entrained as blood passed through the lumen of the tube, resulting in air remaining in the lumen of the tube. Specifically, it was confirmed that blood sometimes flowed forcefully into the lumen of the tube and circled toward the base end rather than the air, resulting in air remaining in the lumen of the tube without being expelled to the base end.

[0007] The problem to be solved by the present invention is to provide a connector with a hemostatic valve having a novel structure that can reduce residual air in the inner lumen of a tube and the internal flow path of a connector with a hemostatic valve.

[0008] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0009] In the first aspect, there is provided a connector with a hemostatic valve, in which an internal flow path, the tip of which is connected to a blood vessel via a tube, is blocked by a hemostatic valve, and the hemostatic valve is switched to a communicating state when an external connector is connected from the base end. An air vent passage that connects the internal flow path to the external space is provided so as to open into the internal flow path on the tip side of the hemostatic valve, and a breathable filter that allows air to pass but restricts the passage of blood is provided on the path of the air vent passage. When the hemostatic valve is closed and an air pressure of 20 kPa is applied from the tip side of the internal flow path, the amount of air discharged outside the internal flow path is 150 mL / min or less.

[0010] In the connector with a hemostatic valve constructed according to this aspect, the flow rate of blood flowing from the distal end into the internal flow path is limited by intentionally restricting the amount of air discharged from the internal flow path. That is, since the volume of blood flowing into the internal flow path is approximately the same as the volume of air discharged from the internal flow path, restricting the amount of blood flowing into the internal flow path limits the amount of blood flowing into the internal flow path, thereby suppressing the blood flow rate. By intentionally restricting the flow rate so that blood flows slowly into the internal flow path, the inflowing blood is less likely to advance toward the proximal end than the air in the lumen and internal flow path of the tube, and air is less likely to remain behind because the advanced blood prevents it from moving toward the proximal end. This reduces the risk of a large amount of residual air entering a blood vessel during, for example, administration of medication or transfusion from the lumen and internal flow path of the tube into a blood vessel.

[0011] In a second aspect, in the connector with a hemostatic valve described in the first aspect, the tube is a soft tube having a length in the range of 50 to 410 mm, and a hollow needle with a sharp blade surface for puncturing is connected to the tip side of the tube.

[0012] With a hemostatic valve connector constructed according to this embodiment, even in cases where the amount of residual air is particularly important (e.g., a blood circuit for dialysis) due to the use of a specific soft tube, application of the present invention effectively prevents air from remaining in the internal flow path. In other words, the longer the tube, the easier it is to connect an external device, such as an external circuit, to the hemostatic valve connector, but the greater the risk of air remaining in the tube. However, application of the present invention can achieve both improved maneuverability and a reduced risk of air remaining in the tube. For this reason, the length of the tube is preferably 50 mm or longer. Furthermore, since the longer the tube, the longer it takes to expel air, it is preferable that the length of the tube be 410 mm or less to prevent excessive air expulsion.

[0013] In addition, in the connector with a hemostatic valve described in the first embodiment, it is also possible to adopt, as another embodiment, a tube in which the tube is a soft tube having a length in the range of 70 to 410 mm, and a hollow needle with a sharp blade surface for puncturing is connected to the tip side of the tube.

[0014] In addition, in the connector with a hemostatic valve described in the first embodiment, it is also possible to adopt, as another embodiment, a tube that is a soft tube having a length in the range of 110 to 410 mm, and a hollow needle with a sharp blade surface for puncturing is connected to the tip side of the tube.

[0015] In a third aspect, there is provided a method for manufacturing a connector with a hemostatic valve, in which an internal flow path, the tip of which is connected to a blood vessel via a tube, is blocked by a hemostatic valve, and the hemostatic valve is switched to a communicating state when an external connector is connected from the base end. A breathable filter that allows air to pass but restricts the passage of blood is placed on the path of an air vent passage that opens into the internal flow path on the tip side of the hemostatic valve and connects the internal flow path to the external space, compressed and positioned so that when an air pressure of 20 kPa is applied from the tip side of the internal flow path with the hemostatic valve closed, the amount of air discharged outside the internal flow path is 150 mL / min or less.

[0016] According to the manufacturing method of the connector with a hemostatic valve of this aspect, the breathable filter can be compressed to reduce its breathability, and it is easy to design the breathable filter so that the amount of air discharged from the internal flow path is 150 mL / min or less when the breathable filter is subjected to an air pressure of 20 kPa. This effectively restricts the passage of air through the breathable filter, making it possible to prevent air from remaining when the internal flow path is filled with liquid. Furthermore, compared to when the amount of air discharged is adjusted without compressing the breathable filter, the freedom of selection of breathable filters can be expanded.

[0017] According to the present invention, in a connector with a hemostatic valve, the amount of residual air can be reduced by controlling the inflow of blood into the inner cavity of the tube and the internal flow path of the connector with a hemostatic valve.

[0018] FIG. 3 is a cross-sectional view of a needle assembly equipped with a connector with a hemostatic valve according to a first embodiment of the present invention; FIG. 4 is a photograph showing a device for measuring the breathability of a breathable filter in a connector with a hemostatic valve according to the present invention; FIG. 5 is a table of measurement results using the breathability measuring device shown in FIG. 2; FIG. 6 is a photograph showing the results of a priming test using an indwelling needle equipped with a connector with a hemostatic valve according to the present invention; and FIG. 7 is a photograph showing the results of a priming test using an indwelling needle equipped with a connector with a hemostatic valve according to a conventional structure.

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] Figure 1 shows a needle assembly 12 equipped with a hemostatic valve connector 10 according to a first embodiment of the present invention. The needle assembly 12 has a structure in which a butterfly needle 16 is connected to the distal end of a tube 14, and the hemostatic valve connector 10 is connected to the proximal end of the tube 14. In the following description, the distal end refers to the left side in Figure 1, which is the side of the needle tip 22 of a hollow needle 18 (described later) that is the side that is inserted into the patient, and the proximal end refers to the right side in Figure 1 that is the side that is connected to an external circuit (not shown). Furthermore, the upward direction refers to the direction in which the blade surface 20 is provided, perpendicular to the needle axis of the hollow needle 18 (described later).

[0021] The tube 14 is a soft tube made of, for example, a soft synthetic resin, which is easily bent and deformed while also allowing for elastic deformation in diameter expansion. The length dimension L of the tube 14 is preferably set within a range of 50 to 410 mm, and more preferably within a range of 70 to 360 mm. Alternatively, the length dimension L of the tube 14 may be set within a range of 70 to 410 mm. Alternatively, the length dimension L of the tube 14 may be set within a range of 110 to 410 mm. The inner diameter dimension φ of the tube 14 is set within a range of, for example, 2.8 to 3.8 mm, preferably within a range of 3.4 to 3.8 mm, and more preferably within a range of 3.45 to 3.6 mm. This ensures a flow rate of infusion or medicinal solution through the tube 14 while effectively preventing air from remaining during priming, which fills the lumen of the tube 14 with liquid. Preferably, the inner diameter φ of the tube 14 is set so that the difference between it and the inner diameter of the hollow needle 18 (described later) is 1.1 mm or less, which more effectively prevents air from remaining in the lumen of the tube 14 when the lumen is filled with liquid. The length L and inner diameter φ of the tube 14 are preferably set within the above-mentioned ranges, but may be outside the above-mentioned ranges.

[0022] The winged needle 16 includes a hollow needle 18 for puncture. The hollow needle 18 has a blade surface 20 that slopes downward toward the tip, and the blade surface 20 forms a sharp needle tip 22 at the tip. The hollow needle 18 is formed of a metal material, such as medical stainless steel. The thickness (inner diameter) of the hollow needle 18 is not particularly limited, but is preferably within the range of 14 to 18 gauge, which is also used for dialysis, for example. A needle hub 24 is connected to the proximal end of the hollow needle 18. The needle hub 24 has a generally cylindrical shape overall and is formed of, for example, a hard synthetic resin. A small-diameter cylindrical connecting portion 26 that protrudes toward the proximal end is integrally formed on the needle hub 24. A wing-shaped member 28 is attached to the needle hub 24. The wing-shaped member 28 is formed of, for example, a soft synthetic resin. The wing-like member 28 has a cylindrical mounting tube portion 30 that is attached to the needle hub 24 in an externally inserted state, and plate-like wing portions 32, 32 protrude on both sides from the mounting tube portion 30 in the tangential direction of the mounting tube portion 30.

[0023] The connecting portion 26 of the needle hub 24 of the butterfly needle 16 is connected to the distal end of the tube 14 in an inserted state, and the butterfly needle 16 is provided on the distal side of the tube 14. Therefore, the inner diameter dimension of the connecting portion 26 is smaller than the inner diameter dimension φ of the tube 14. A step portion 34 is formed on the inner periphery of the tube 14 by the proximal end surface of the connecting portion 26 inserted into the tube 14. The step portion 34 is an annular plate-like shape that extends approximately perpendicular to the axial direction of the cylindrical connecting portion 26. That is, the step portion 34 is provided within an internal flow path 42 (described below) distal to the opening position of an air vent passage 70 (described below), and the internal flow path 42 has a larger diameter proximal to the distal side relative to the step portion 34. The distal end of the tube 14 and the connecting portion 26 of the outer needle hub 24 may be fitted together without adhesive, but are preferably fixed by means of adhesive bonding, welding, or the like.

[0024] The hemostatic valve-equipped connector 10 has a structure in which a hemostatic valve 38 and a plunger 40 are housed in a cylindrical valve housing 36. The valve housing 36 has an internal flow path 42 that penetrates in the axial direction, and the distal end portion of a connector member 46, which serves as a plunger guide, is inserted into the proximal end portion of a cover member 44, thereby interconnecting the cover member 44 and the connector member 46. Note that the connector member 46 in this embodiment has both the function of connecting to an external connector 80 (described later) and the function of guiding the plunger 40, and although the connector member 46 is used as a plunger guide, the function of guiding the plunger 40 may be realized by a separate member, and the connector member 46 does not necessarily have to have a plunger guide function.

[0025] The cover member 44 is made of, for example, a hard synthetic resin material. The cover member 44 has a stepped cylindrical shape with a distal end portion having a smaller diameter than a proximal end portion. A pair of engagement holes 48, 48 are formed through the proximal end portion of the cover member 44 on both radial sides.

[0026] A support member 50 is attached to the cover member 44 in an inserted state. The tip portion of the support member 50 is overlapped and fixed to the inner circumferential surface of the small-diameter tip portion of the cover member 44. The base end portion of the support member 50 is located away from the large-diameter base end portion of the cover member 44 toward the inner circumferential surface. Communication holes 52 opening onto the inner and outer circumferential surfaces of the support member 50 are formed on both radial sides thereof. The communication holes 52 communicate with the space between the radially opposing surfaces of the cover member 44 and the support member 50 at their openings on the outer circumferential side. The support member 50 is fixed to the cover member 44 and, together with the cover member 44, constitutes part of the valve housing 36.

[0027] The connector member 46 has a generally cylindrical shape overall. The distal end portion of the connector member 46 has a stepped diameter that decreases toward the distal end, and a pair of engaging protrusions 54, 54 that protrude from the outer circumferential surface are formed at the maximum diameter portion. The proximal end portion of the connector member 46 has an outer diameter smaller than the maximum diameter portion of the distal end portion, and a luer taper is set on the inner circumferential surface. The proximal end portion of the connector member 46 is provided with a male thread portion 56 that protrudes toward the outer periphery.

[0028] The plunger 40 is disposed on the inner periphery of the connector member 46. The plunger 40 has a generally cylindrical shape overall, with the outer circumferential surface of the tip portion tapering to a smaller diameter toward the tip, and the outer circumferential surface of the base end portion being a cylindrical surface of a generally constant diameter.

[0029] The connector member 46 has its tip portion inserted into the larger-diameter base end portion of the cover member 44, and the engaging protrusions 54, 54 of the connector member 46 are inserted into the engaging holes 48, 48 of the cover member 44 and engaged in the axial direction, thereby connecting the two members to each other.

[0030] The hemostasis valve 38 is a disk valve having a generally circular disk shape overall, and is formed from an elastic material such as a resin elastomer or rubber. The hemostasis valve 38 has radial notches 60 formed in its central portion, and the notches 60 are opened and closed by elastic deformation of the central portion. A cylindrical clamping portion 62 that protrudes toward the base end is integrally formed on the outer peripheral end of the hemostasis valve 38. Note that the hemostasis valve is not limited to a disk valve, and other valves such as a duckbill valve can also be used.

[0031] The hemostatic valve 38 is disposed in the internal flow path 42 of the valve housing 36. The clamping portion 62 of the hemostatic valve 38 is clamped in the axial direction between the tip of the connector member 46 and a support member 50 disposed on the inner periphery of the cover member 44, whereby the hemostatic valve 38 is supported at its outer periphery by the valve housing 36. The inner periphery ends of the communication holes 52, 52 penetrating the support member 50 open to the inner periphery at a position distal to the hemostatic valve 38.

[0032] The hemostatic valve 38 housed in the valve housing 36 is compressed radially, and the inner surfaces of the notches 60 are pressed against each other in a closed state. Therefore, the internal flow path 42 of the hemostatic valve-equipped connector 10, which is formed by the inner cavity of the valve housing 36, is blocked by the hemostatic valve 38. The internal flow path 42 of the hemostatic valve-equipped connector 10 is divided into a distal side and a proximal side of the hemostatic valve 38 in the closed state, with the distal side of the hemostatic valve 38 in the internal flow path 42 being a first internal space 66, and the proximal side of the hemostatic valve 38 in the internal flow path 42 being a second internal space 68.

[0033] An air vent passage 70 is formed by the space between the radially opposing surfaces of the cover member 44, the support member 50, and the connector member 46, and by the communication holes 52 that radially penetrate the support member 50, and the first internal space 66 of the internal flow path 42 is open to the outside space through the air vent passage 70. The air vent passage 70 is connected to the first internal space 66 at the inner circumferential openings of the communication holes 52, 52, on the distal side of the hemostasis valve 38, and is also connected to the outside space by gaps 58, 58 between the distal end faces of the engaging protrusions 54, 54 and the distal inner surfaces of the engaging holes 48, 48. The cross-sectional area of ​​the air vent passage 70 is sufficiently smaller than that of the internal flow path 42, thereby allowing the flow of gas (air) while restricting the flow of liquid (blood). Furthermore, the cross-sectional area of ​​the air vent passage 70 in this embodiment is increased in the middle portion, and if blood enters the air vent passage 70, the blood will accumulate in the middle portion, making it less likely for the blood to leak into the external space.

[0034] A breathable filter 72 is disposed on the path of the air vent passage 70. The breathable filter 72 is a filter that allows gas to pass through but restricts the passage of liquids such as blood, and is cylindrical or annular. Because the breathable filter 72 is cylindrical or annular, it is possible to easily adjust the compression amount of the breathable filter 72, and it is possible to more stabilize the amount of air discharged through the breathable filter 72 when a predetermined air pressure is applied to the internal flow path 42.

[0035] The breathable filter 72 is, for example, a porous body formed by melting and bonding a large number of synthetic resin particles together to provide continuous pores between the particles. Alternatively, the breathable filter 72 may be, for example, a sintered body containing a superabsorbent polymer (SAP). When the breathable filter 72 contains such a superabsorbent polymer, air is allowed to pass through in the initial state until blood comes into contact with the breathable filter 72. However, once blood comes into contact with the breathable filter 72, the superabsorbent polymer absorbs the blood and swells, restricting the passage of blood.

[0036] The breathable filter 72 is attached to the rigid valve housing 36. More specifically, the breathable filter 72 is disposed radially between the cover member 44 and the support member 50, which are components of the valve housing 36. The breathable filter 72 is disposed in the air vent passage 70 while being compressed radially between the cover member 44 and the support member 50. The radial compression rate of the breathable filter 72 is specifically within a range of 3 to 43%, preferably within a range of 7 to 41%, and more preferably within a range of 8 to 40%. The breathable filter 72 is disposed in a position that covers the outer peripheral openings of the communication holes 52, 52, and is located above the air vent passage 70. Because the breathable filter 72 is disposed above the air vent passage 70 in a compressed state, the holes of the breathable filter 72 are smaller than when the filter is alone. This allows for greater freedom in selecting the breathable filter 72 compared to when the breathable filter 72 is assembled without compression, while also allowing air in the first internal space 66 of the internal flow path 42 to pass through the breathable filter 72 and be discharged to the external space. Furthermore, the breathable filter 72 prevents liquids such as blood that flow into the first internal space 66 from leaking into the external space. The breathable filter 72 can also be provided so as to be compressed in the axial direction rather than the radial direction. Although it is preferable that the breathable filter 72 be assembled in a compressed state, it is not essential that the breathable filter 72 be assembled in a compressed state.

[0037] The hemostatic valve-equipped connector 10 constructed as described above is connected to the proximal end of the tube 14. That is, the proximal end of the tube 14 is inserted distally into the support member 50 that constitutes the valve housing 36 of the hemostatic valve-equipped connector 10, and is fixed by adhesive or other means to the inner circumferential surface of the distal portion of the support member 50. This allows the inner cavity of the tube 14 and the internal flow path 42 of the hemostatic valve-equipped connector 10 to communicate with each other.

[0038] In the hemostatic valve-equipped connector 10, when an air pressure of 20 kPa is applied from the distal end of the internal flow path 42 with the hemostatic valve 38 closed, the rate of air discharge from the internal flow path 42 to the external space is set to 150 mL / min or less. Furthermore, under the above conditions, the hemostatic valve-equipped connector 10 is desirably set to have an air discharge rate of 50 mL / min or more, more preferably 100 mL / min or more. Furthermore, if the rate of air discharge from the internal flow path 42 is set to less than 50 mL / min, a long time is required for priming the internal flow path 42 to fill it with liquid before use of the hemostatic valve-equipped connector 10, which may result in waiting times in busy medical settings and reduced efficiency.

[0039] In this embodiment, the air in the internal flow path 42 is discharged to the external space through the air vent passage 70 in which the breathable filter 72 is arranged, and therefore the air discharge performance (air permeability) from the internal flow path 42 can be set by adjusting the dimensions of the air vent passage 70, the diameter of the fine holes in the breathable filter 72 alone, the effective area of ​​the breathable filter 72 when attached, or the compressibility of the breathable filter 72, etc.

[0040] It is preferable that the amount of air discharged from the internal flow path 42 to the external space be reduced by compressing the breathable filter 72. If the amount of air discharged is reduced below a predetermined value without compressing the breathable filter 72, it becomes difficult to manufacture the breathable filter 72, and there is a possibility that the manufacturing cost will increase significantly. It is also possible to limit the air discharge performance without using the breathable filter 72 by adjusting the dimensions of the members themselves that form the wall of the air vent passage 70, but this is not realistic because an extremely high degree of dimensional accuracy is required.

[0041] When adjusting the air discharge performance by changing the dimensions of the air vent passage 70, it is preferable to separately provide a discharge adjustment member that adjusts the air discharge amount through the air vent passage 70 and place the discharge adjustment member on the air vent passage 70 to adjust the air discharge performance. For example, a ring-shaped member may be placed on the air vent passage 70 as the discharge adjustment member, and the amount of air discharged may be reduced by, for example, forming small openings in the ring-shaped member or by solidifying a fibrous member into a ring shape. The discharge adjustment member may be a non-porous material, but a porous material may also be used. If the discharge adjustment member is porous, compressing the discharge adjustment member reduces the pore diameter, thereby reducing the amount of air discharged compared to when it is uncompressed. A porous discharge adjustment member makes it easier to stabilize the amount of air discharged during assembly.

[0042] The material and characteristics of the breathable filter 72 employed in the present invention are not limited. For example, a suitable breathable filter 72 has the following characteristics: when a cylindrical filter test piece, in its stand-alone state, has an inner diameter of 6.5 mm, an outer diameter of 8.2 mm, and a height (axial length) of 2 mm, the filter test piece has an airflow resistance of 80 kPa or more for air passing from the inner periphery to the outer periphery (atmospheric pressure) of the filter test piece when an air pressure of 100 kPa is applied to the inner periphery of the filter test piece. By adjusting the size and shape of a filter test piece with such an airflow resistance value and applying the breathable filter 72 to the hemostatic valve-equipped connector 10 and assembling the breathable filter 72 in a compressed state, the air discharge rate when an air pressure of 20 kPa is applied from the distal end of the internal flow path 42 with the hemostatic valve 38 closed can be easily controlled to 150 mL / min or less. However, it is also possible to adopt a breathable filter 72 that does not correspond to the filter test specimen for which the above-mentioned air resistance value is set, and adjust the compressive force of the breathable filter 72 so that the air discharge amount when an air pressure of 20 kPa is applied is 150 mL / min or less.

[0043] The needle assembly 12 constructed according to this embodiment can be manufactured by a manufacturing method including the steps of preparing a butterfly needle 16, preparing a tube 14, preparing a hemostatic valve connector 10, and assembling the butterfly needle 16, the tube 14, and the hemostatic valve connector 10. Furthermore, a manufacturing method for the hemostatic valve connector 10 that can be applied to the step of preparing the hemostatic valve connector 10 includes the steps of preparing a hemostatic valve 38, preparing a breathable filter 72, preparing a valve housing 36, and assembling the hemostatic valve 38 and the breathable filter 72 to the valve housing 36.

[0044] In the process of assembling the hemostatic valve 38 and the breathable filter 72 to the valve housing 36 in the manufacturing method of the hemostatic valve-equipped connector 10, the breathable filter 72 is disposed between the components of the valve housing 36, and compressed and disposed between the cover member 44 and the support member 50 so that when an air pressure of 20 kPa is applied from the tip side of the internal flow path 42 with the hemostatic valve 38 closed, the rate of air discharge from the internal flow path 42 to the external space (atmospheric pressure) is 150 mL / min or less. The manufacturing method of the hemostatic valve-equipped connector 10 includes the steps of forming the valve housing 36 so that the cross-sectional area (inside dimensions) of the arrangement space for the breathable filter 72 is smaller than the cross-sectional area (outside dimensions) of the breathable filter 72, and disposing the breathable filter 72 in the arrangement space and compressing the breathable filter 72.

[0045] By assembling the breathable filter 72 in a compressed state in this way, it is possible to stably adjust the amount of air discharged while reducing the manufacturing cost of the breathable filter 72. More specifically, for example, during the manufacturing of the hemostasis valve-equipped connector 10, the breathable filter 72 can be disposed in the installation space in the valve housing 36 and compressed so that the compression rate of the breathable filter 72 is within the range of 7 to 41%. Without compression, a breathable filter with a smaller average pore size would be required to reduce air discharge performance, and the required performance of the breathable filter would increase, resulting in increased manufacturing costs. Increasing the compression rate increases the likelihood of problems occurring during assembly of the breathable filter, resulting in lower yields.

[0046] In the needle assembly 12 constructed according to this embodiment, the hollow needle 18 is inserted into a patient's blood vessel. In this embodiment, the butterfly needle 16 is provided at the distal end of the tube 14, so that the wings 32, 32 can be overlapped at the top and pinched with the fingertips to perform the puncture. Furthermore, when the butterfly needle 16 is left inserted into the blood vessel, the wings 32, 32 can be positioned and held against the patient's skin with tape or other means to prevent unintentional withdrawal from the blood vessel.

[0047] When the hollow needle 18 is inserted into a blood vessel, blood flows into the lumen of the hollow needle 18, flows through the lumen of the tube 14 toward the proximal end, and into the first internal space 66 of the internal flow path 42 of the hemostatic valve-equipped connector 10. At this time, air filling the lumen of the hollow needle 18, the lumen of the tube 14, and the first internal space 66 of the hemostatic valve-equipped connector 10 is discharged to the external space through the air vent passage 70 as the blood flows in. This allows priming to be performed, filling the first internal space 66 with blood, before connecting the external connector 80, which will be described later. The blood that has flowed into the air vent passage 70 is prevented from leaking into the external space by a breathable filter 72 containing a highly absorbent polymer.

[0048] Here, the breathable filter 72 of the hemostatic valve connector 10 limits the amount of air passing through per unit time so that when an air pressure of 20 kPa is applied from the tip side of the internal flow path 42 with the hemostatic valve 38 closed, the amount of air discharged to the external space through the air vent passage 70 is 150 mL / min or less. Since the amount of blood flowing in from the blood vessel is approximately the same as the amount of air discharged through the air vent passage 70, the amount of blood flowing in from the blood vessel is limited by the breathable filter 72. Therefore, in the needle assembly 12 equipped with the hemostatic valve connector 10, the inflow rate of blood from the blood vessel into the internal flow path 42 is reduced, allowing the blood to flow gently into the internal flow path 42. This prevents air from remaining in the flow path formed by the lumen of the tube 14 and the internal flow path 42 of the hemostatic valve connector 10 due to the forceful inflow of blood.

[0049] In this embodiment, the tube 14 is a soft tube (e.g., a tube made of silicone rubber, soft polyvinyl chloride, various resin elastomers, etc.) having a length ranging from 110 to 410 mm. With such a tube 14, the longer the tube 14, the greater the distance between the butterfly needle 16 and the hemostatic valve-equipped connector 10, improving the operability (handling) of the hemostatic valve-equipped connector 10. This allows medical personnel to connect the hemostatic valve-equipped connector 10 to the end of the blood circuit at a position closer to them, thereby facilitating the connection process. Meanwhile, since a long tube 14 increases the likelihood of a large amount of residual air remaining in the internal flow path 42, combining a long tube 14 with a breathable filter 72 with limited breathability effectively prevents a large amount of air from remaining in the internal flow path 42.

[0050] Differences in the ability of a hemostatic valve connector to expel air from the internal flow path to the external space affect the degree of air remaining in the flow path. Therefore, we conducted experiments to verify whether air retention in the flow path during priming can be suppressed by adjusting the average pore size and compressibility of the porous material to control the air release rate and reduce the blood inflow rate into the internal flow path. We then conducted experiments to confirm the degree of air retention in the flow path of a hemostatic valve connector in which air retention is effectively suppressed. As a result, we confirmed that when an air pressure of 20 kPa was applied and the air flow rate per unit time was limited so that the rate of air released into the external space through the air vent passage 70 was 150 mL / min or less, the phenomenon of air entrainment by blood in the tube 14 was not observed. As a representative example, two types of breathable filters with different air permeabilities were prepared, and the results of measuring the air release rate of a hemostatic valve connector using these two types of breathable filters using the measuring device 74 shown in Figure 2 are shown.

[0051] The measuring device 74 in Figure 2 applies a desired air pressure to the internal flow path of the hemostatic valve connector from the distal end using a pump (not shown). The air pressure applied from the pump to the measuring device 74 is adjusted to 20 kPa by a pressure regulating valve 76 and applied to the internal flow path of the hemostatic valve connector from the distal end. A flow meter 78 that measures and displays the air flow rate is provided on the path connecting the pressure regulating valve 76 and the hemostatic valve connector, and the flow meter 78 measures the flow rate of air discharged from the internal flow path of the hemostatic valve connector to the external space. Note that the structure of the hemostatic valve connector used to measure the breathability performance using the measuring device 74 in Figure 2 is substantially the same as the hemostatic valve connector 10 according to this embodiment, and therefore, for ease of understanding, the hemostatic valve connector is designated by the symbol 10 in Figure 2. Furthermore, the hemostatic valve of the hemostatic valve connector is in a closed state during measurement.

[0052] Figure 3 shows the results of measurements using the measuring device 74 shown in Figure 2 for two types of hemostatic valve-equipped connectors, an example and a comparative example. The comparative example is a conventional hemostatic valve-equipped connector, in which a filter having an average pore size of 20 to 30 μm in its standalone state is sandwiched between the cover member 44 and the support member 50 so as to achieve a compression ratio of 8 to 40%. On the other hand, the example is a filter having an average pore size of 5 to 6 μm in its standalone state, sandwiched between the cover member 44 and the support member 50 so as to achieve a compression ratio of 8 to 40%, further compressing the filter with a smaller average pore size and limiting the amount of air discharged. The measurement results for the example hemostatic valve-equipped connector were 72 to 142 mL / min, which was confirmed by actual measurements to be below 150 mL / min. On the other hand, the measurement results for the comparative example hemostatic valve-equipped connector were 410 to 517 mL / min, which was confirmed by actual measurements to be significantly higher than 150 mL / min. FIG. 3 shows the results of measurements carried out on five hemostatic valve-equipped connectors of the example and five hemostatic valve-equipped connectors of the comparative example.

[0053] Next, a needle assembly equipped with a hemostatic valve-equipped connector according to the example and a needle assembly equipped with a hemostatic valve-equipped connector according to the comparative example were prepared, and a priming test was conducted in which simulated blood was introduced into the internal flow path from the tip of each needle assembly under the same conditions. In the priming test, the tip of the needle assembly was held facing downward at a 45-degree angle relative to the horizontal, and simulated blood was introduced into the tip at a pressure of 150 mmHg. A 50% by weight glycerin solution was used as the simulated blood. The needle assemblies of the example and the comparative example were identical except for the breathable filter, and both had the structure of the needle assembly 12 described in the embodiment.

[0054] The results of the priming test are shown in Figure 4. Figure 4A shows the results of the priming test for the needle assembly equipped with the hemostatic valve connector of the example. Figure 4A shows that when the hemostatic valve connector of the example was used, no air remained in the flow path, and the entire flow path was filled with artificial blood.

[0055] Figure 4B shows the results of a priming test on a needle assembly equipped with a comparative hemostatic valve connector. Figure 4B shows that when the comparative hemostatic valve connector was used, air remained in the lumen of the tube 14. In particular, air remained significantly at the connection between the outer needle hub 24 and the tip of the tube 14 due to the step 34. For ease of viewing, the remaining air in the tube 14 is indicated by the letter A in Figure 4B.

[0056] In this way, by comparing the connector 10 with a hemostatic valve of the embodiment with a conventional connector with a hemostatic valve, it was confirmed through experiments that by reducing the amount of air passing through the breathable filter 72, air is prevented from remaining when blood flows in.

[0057] As shown in Fig. 5 , an external connector 80 is connected to the hemostatic valve-equipped connector 10 whose first internal space 66 is filled with blood. The external connector 80 has a male luer portion 82, which may be, for example, a male connector of an infusion circuit or a syringe tip. The male luer portion 82 has a luer taper on its outer circumferential surface, and the external connector 80 is connected to the hemostatic valve-equipped connector 10 by inserting the male luer portion 82 into the connector member 46 of the valve housing 36 from the proximal end side. This connects the flow path within the external connector 80 to the second internal space 68 in the internal flow path 42 of the hemostatic valve-equipped connector 10.

[0058] When the external connector 80 is connected, the plunger 40 is pushed toward the distal end by the external connector 80 and displaced. As a result, the distal end of the plunger 40 penetrates the notch 60 of the hemostatic valve 38 while pushing the notch 60 apart, switching the hemostatic valve 38 to a communicating state. As a result, the first internal space 66 and the second internal space 68 in the internal flow path 42 of the hemostatic valve-equipped connector 10 are connected to each other through the lumen of the plunger 40. The flow path within the external connector 80, which is connected to the second internal space 68, is then connected to a blood vessel through the internal flow path 42, the tube 14, and the lumen of the hollow needle 18, enabling blood purification such as dialysis, or administration of medicine or blood transfusion into a blood vessel from the external connector 80 side.

[0059] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific description. For example, the breathable filter 72 is not limited to the synthetic resin sintered body shown in the first embodiment. Various breathable filters having predetermined breathability (air permeability characteristics) can be used. Specifically, the breathable filter can be formed of a porous body made of a material other than resin, such as ceramic, or a porous membrane (including a laminated structure). While such a breathable filter is preferably attached in a compressed state, it can also be attached in an uncompressed state. For example, a breathable filter made of a hard material can be attached by overlaying an elastic sealant on the contact surface. The above-described air discharge characteristics through the breathable filter need only be satisfied by the hemostasis valve-equipped connector when the breathable filter is attached. It is also possible to use a stack of multiple breathable filters made of the synthetic resin sintered body shown in the first embodiment.

[0060] In the first embodiment, the breathable filter 72 is directly superimposed on the cover member 44 and the support member 50, which are hard members, and is directly sandwiched and compressed between these hard members. However, for example, the breathable filter 72 may be compressed via a soft member. This soft member may be disposed as a separate component, or may be configured as part of the valve body, for example. Furthermore, the breathable filter 72 does not need to be a single member but may be configured from multiple divided structures, and its specific shape is not limited.

[0061] The path for discharging air from the internal flow path of the hemostatic valve-equipped connector to the external space is not necessarily limited to the air vent passage provided with a breathable filter, and it is sufficient that the overall amount of air discharged out of the internal flow path when an air pressure of 20 kPa is applied from the distal end side of the internal flow path is 150 mL / min or less. Therefore, for example, an air discharge path separate from the air vent passage may be provided, and the air discharge path may not have a breathable filter, or a breathable filter separate from that provided in the air vent passage may be provided.

[0062] The specific structure of the hemostatic valve-equipped connector 10 is not necessarily limited to that described in detail in the above embodiment. For example, in the first embodiment, in the valve housing 36, the filter-fixing housing that fixes the breathable filter 72 is composed of a cover member 44 and a support member 50, and the valve-fixing housing that fixes the hemostatic valve 38 is composed of a connector member 46 and a support member 50. Although the filter-fixing housing and the valve-fixing housing are not identical, as shown in FIG. 3 of WO 2019 / 027024, the filter-fixing housing and the valve-fixing housing may be identical. Also, as shown in FIG. 3 of WO 2019 / 027024, the breathable filter may be disposed closer to the base end than the hemostatic valve, allowing air to be discharged to the outside through the outer surface of the hemostatic valve. Also, as shown in FIG. 3 of WO 2019 / 146791, the breathable filter may be non-cylindrical, and the member that fixes the breathable filter is not limited to being cylindrical.

[0063] The needle hub 24 is not necessarily limited to being connected to the distal end of the tube 14 in an inserted state; for example, it may be connected to the distal end of the tube 14 in an externally inserted state, or the needle hub 24 and the tube 14 may be connected in a state where they are abutted against the distal surface of the tube 14 so as not to create a step in which the inner diameter expands toward the base end. As disclosed in International Publication No. 2021 / 261500, it has been confirmed that the more a step in which the inner diameter expands toward the base end, the greater the tendency for air to remain in the tube 14. Therefore, connecting the tube 14 and the needle hub 24 so as not to create a step is expected to reduce the possibility of air remaining. Conversely, the present invention can be suitably applied when there is a step in which the inner diameter expands toward the base end.

[0064] As a modified example, for example, in an indwelling needle assembly having a structure in which an inner needle unit having an inner needle hub provided on the proximal end of an inner needle and an outer needle unit having an outer needle hub provided on the proximal end of an outer needle as a tube inserted over the inner needle are combined with each other, the structure of the connector with a hemostatic valve according to the present invention can be applied to the outer needle hub. In fact, when the structure shown in Figure 12 of WO 2019 / 146791 was tested under similar conditions (pore size and compressibility of the fine pores in the filter), it was confirmed that an indwelling needle adjusted so that the rate of air discharged into the external space through the air vent passage was 150 mL / min or less when an air pressure of 20 kPa was applied to the filter did not exhibit air entrapment. The indwelling needle shown in Figure 12 of WO 2019 / 146791 has a tube length of 26 mm, including the adhesive portion to the hub and connector, but there is a step at the connection between the tube and the needle hub. Furthermore, the longer the tube length, the more freely the connector can move, but the more likely the connector will hang downward due to the action of gravity, making the tube more likely to bend, and if liquid flows through the tube in such a bent state, air is likely to remain in the bent portion.Thus, although the present invention is not limited to a specific tube length, it is particularly suitable for indwelling needle assemblies having tubes with lengths within the range of 110 to 410 mm.

[0065] REFERENCE SIGNS LIST 10 Connector with hemostatic valve (first embodiment) 12 Needle assembly 14 Tube 16 Winged needle 18 Hollow needle 20 Blade surface 22 Needle tip 24 Needle hub 26 Connection portion 28 Winged member 30 Mounting tube portion 32 Wing portion 34 Step portion 36 Valve housing 38 Hemostatic valve 40 Plunger 42 Internal flow path 44 Cover member 46 Connector member (plunger guide) 48 Engagement hole 50 Support member 52 Communication hole 54 Engagement protrusion 56 Male thread portion 58 Gap 60 Notch 62 Clamping portion 66 First internal space 68 Second internal space 70 Air vent passage 72 Breathable filter 74 Measuring device 76 Pressure regulating valve 78 Flow meter 80 External connector 82 Male luer portion A Residual air

Claims

1. A connector with a hemostatic valve, in which an internal flow path, the tip of which is connected to a blood vessel via a tube, is blocked by a hemostatic valve, and the hemostatic valve is switched to a communicating state when an external connector is connected from the base end, and an air vent passage connecting the internal flow path to the external space is provided so as to open into the internal flow path on the tip side of the hemostatic valve, and a breathable filter is provided on the path of the air vent passage to allow the passage of air but restrict the passage of blood, and when an air pressure of 20 kPa is applied from the tip side of the internal flow path with the hemostatic valve closed, the amount of air discharged outside the internal flow path is 150 mL / min or less.

2. A connector with a hemostatic valve as described in claim 1, wherein the tube is a soft tube having a length within the range of 50 to 410 mm, and a hollow needle with a cutting edge for puncturing is connected to the tip of the tube.

3. A method for manufacturing a connector with a hemostatic valve, in which an internal flow path, the tip of which is connected to a blood vessel via a tube, is blocked by a hemostatic valve, and the hemostatic valve is switched to a communicating state when an external connector is connected from the base end, wherein a breathable filter that allows air to pass but restricts the passage of blood is compressed and arranged on the path of an air vent passage that opens into the internal flow path on the tip side of the hemostatic valve and connects the internal flow path to the external space, so that when an air pressure of 20 kPa is applied from the tip side of the internal flow path with the hemostatic valve closed, the amount of air discharged outside the internal flow path is 150 mL / min or less.

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