JP7585100B2 - Pressure relief member, connector and infusion tube set - Google Patents

Description

The present invention relates to a pressure relief member, a connector, and an infusion tube set that are provided in an infusion line.

An infusion tube set is used to administer medicinal fluids, physiological saline, etc. to patients. The infusion tube set has an infusion administration section (catheter) that is inserted into the patient to administer infusion fluid into the patient's body, and an infusion tube connected to the base end of the infusion administration section (for example, Patent Document 1). The infusion tube and the infusion administration section are connected via a connector.

JP 2005-334280 A

When using an infusion tube set for angiography, etc., contrast medium is administered into the patient's blood vessels through the infusion tube and catheter. However, because contrast medium has a relatively high viscosity, relatively high pressure can act on the catheter, connector, etc., which may cause damage to the catheter or connector, or leakage of the drug from the connector connection.

In addition, damage or leakage from catheters or connectors due to pressure may also occur when administering highly viscous liquids other than contrast agents.

The purpose of one embodiment is to provide a pressure relief member, connector, and infusion tube set that can prevent the generation of excessive pressure when administering a highly viscous infusion, thereby preventing damage to each part and leakage of the infusion.

One aspect of the disclosure below is a pressure relief member that is connected to an infusion line and allows the drug solution in the infusion line to flow, and that includes a hollow elastic body that elastically deforms and expands in response to the pressure in the infusion line, an expansion restriction mechanism that contacts the outer surface of the hollow elastic body to restrict the expansion of the hollow elastic body, and a return mechanism that promotes the return of the hollow elastic body from its expanded state to its original shape.

Another aspect is a connector that includes the pressure relief member of the above aspect and a connector body that can be connected to a catheter that is placed in a blood vessel, and the pressure relief member is integrally provided on the base end side of the connector body.

Another aspect is an infusion tube set that includes the pressure relief member of the above aspect, a connector body that can be connected to a catheter placed in a blood vessel, and an infusion tube that is connected to the base end side of the connector body, and in which the connector body and the infusion tube are connected via the pressure relief member.

The above pressure relief member, connector and infusion tube set can mitigate the sudden increase in pressure when administering a highly viscous infusion, preventing damage to various parts and leakage of the infusion.

FIG. 2 is an explanatory diagram of an infusion tube set according to the first embodiment. FIG. 2 is an explanatory diagram showing the catheter and catheter hub of FIG. 1 in use. 3A is a vertical cross-sectional view of the pressure relief member of FIG. 2, and FIG. 3B is a cross-sectional view of a portion corresponding to line IIIB-IIIB of FIG. 3A. 3 is an explanatory diagram showing the function of the pressure relief member in the initial state of FIG. 2 . 3 is an explanatory diagram showing the function of the pressure relief member in the state in which the pressure in FIG. 2 is applied; FIG. FIG. 11 is a cross-sectional view of a pressure relief member according to a second embodiment. 13A and 13B are explanatory diagrams of a return mechanism and an expansion restriction mechanism of a pressure relief member according to a third embodiment. FIG. 8A is an explanatory diagram of a return mechanism and an expansion restriction mechanism of a pressure relief member according to a fourth embodiment, and FIG. 8B is an explanatory diagram showing the operation of the pressure relief member of FIG. 8A. FIG. 9A is an explanatory diagram of a return mechanism and an expansion restriction mechanism of a pressure relief member according to a fifth embodiment, and FIG. 9B is an explanatory diagram showing the operation of the pressure relief member of FIG. 9A.

Below, preferred embodiments of the pressure relief member, connector, and infusion tube set are presented and described in detail with reference to the attached drawings.

First Embodiment
The infusion tube set 100 of this embodiment is used, for example, for administering infusions, and comprises an infusion bag 102 for containing the infusion, a catheter assembly 104 to be placed in the patient's blood vessel, and a tube 106 (infusion line) connecting the infusion bag 102 and the catheter assembly 104.

The tip of the tube 106 is provided with a connector 12 including a pressure relief member 10 and a connector body 13, and the tube 106 is connected to the catheter assembly 104 via the pressure relief member 10 and the connector body 13. The connector 12 is, for example, a luer lock type connector. As shown in FIG. 2, the connector body 13 is provided with a male luer portion 15 (luer tip 14) that is inserted into the cavity of the catheter hub 108 (catheter assembly 104). The outer periphery of the luer tip 14 is formed with a cylindrical luer lock portion 16 having a screw mechanism formed on the inner periphery into which the flange portion 110 at the base end of the catheter hub 108 is screwed.

A connection port 18 is provided on the base end side of the connector body 13, and one end of the pressure relief member 10 of this embodiment is connected to the connection port 18. A tube 106 is connected to the base end of the pressure relief member 10. The tube 106 is connected to the connector body 13 via the pressure relief member 10.

The catheter assembly 104 is placed in place with the tip of the catheter 112 inserted into the blood vessel 114 and secured to the skin 118 with adhesive tape 116 or the like, as shown.

When a highly viscous infusion such as a contrast agent or anticancer agent is delivered from the infusion bag 102 shown in FIG. 1, the pressure inside the tube 106 may rise suddenly, and without the pressure relief member 10, excessive pressure may act on the connector body 13 and the catheter assembly 104. Such excessive pressure may cause leakage of the infusion from the connection between the connector body 13 and the catheter assembly 104, or damage to the catheter assembly 104. In this embodiment, the pressure relief member 10 is provided on the base end side of the connector body 13 to relieve the pressure rise and prevent the generation of excessive pressure. Details of the pressure relief member 10 are described below.

The pressure relief member 10 of this embodiment includes a housing 20 (see FIG. 3A) connected to the base end side of the connector body 13, and the pressure relief member 10 is provided integrally with the connector body 13. In other words, the connector 12 includes the pressure relief member 10 as a component thereof. Note that the pressure relief member 10 does not need to be integral with the connector body 13, and may be configured to be connected as a separate component midway through the tube 106.

As shown in FIG. 3A, a hollow elastic body 22, an expansion restriction mechanism 24, and a return mechanism 26 are provided inside the housing 20 of the pressure relief member 10. Of these, the hollow elastic body 22 is made of a cylindrical elastic material that allows the flow of medicinal liquid inside. The hollow elastic body 22 is formed to be more flexible than the tube 106, and elastically deforms and expands or contracts in response to the internal pressure, and its diameter can be reversibly increased (or decreased) in response to the pressure.

The hollow elastic body 22 has a first connection part 22b connected to the connection port 18 at its tip side. The first connection part 22b adheres a part of the tip of the hollow elastic body 22 to the connection port 18 in a liquid-tight and air-tight manner, and joins the hollow elastic body 22 to the connection port 18 so that the hollow elastic body 22 does not expand and come off the connection port 18. The hollow elastic body 22 has a cylindrical tube connection port 28 extending from the base end side through the housing 20 at its base end side. The tube connection port 28 is formed to have a diameter that allows the tube 106 to be connected. The hollow elastic body 22 has a second connection part 22c connected to the tube connection port 28 at its base end side. The second connection part 22c adheres a part of the base end of the hollow elastic body 22 to the tube connection port 28 in a liquid-tight and air-tight manner, and joins the hollow elastic body 22 to the tube connection port 28 so that the hollow elastic body 22 does not expand and come off the tube connection port 28.

The expansion restriction mechanism 24 is a member that contacts the outer surface of the hollow elastic body 22 to restrict the expansion of the hollow elastic body 22. Specifically, it includes a pair of pressure plates 30 arranged to sandwich the hollow elastic body 22, an axis rod 32 that guides the movement direction of the pressure plates 30, and restriction portions 36 that are provided on both ends of the axis rod 32 and restrict the movement range of the pressure plates 30.

As shown in FIG. 3B, the pressure plate 30 is formed in a rectangular shape, occupies most of the width of the inside of the housing 20, and is arranged to cover most of the longitudinal direction of the hollow elastic body 22. At the four corners of the pressure plate 30, insertion holes 30a are formed through which the shaft rods 32 are slidably inserted. The shaft rods 32 are inserted into each of the insertion holes 30a. The insertion holes 30a are formed with a diameter slightly larger than the diameter of the shaft rods 32, and the pressure plate 30 is slidable relative to the shaft rods 32 through the insertion holes 30a. The movement direction of the pressure plate 30 is guided by the four shaft rods 32 in the extension direction of the shaft rods 32. The pressure plate 30 has a width that can hold the hollow elastic body 22 even when the hollow elastic body 22 expands.

The shaft rods 32 are formed in a cylindrical shape. The four shaft rods 32 are provided in pairs near the base end and the tip end of the hollow elastic body 22, and are arranged in positions that avoid the hollow elastic body 22 in the width direction. It is preferable to provide the shaft rods 32 in positions that do not interfere with the expanded hollow elastic body 22, such as next to the first connection portion 22b or the second connection portion 22c. Note that the installation position of the shaft rods 32 is not limited to this, and the shaft rods 32 and the expanded hollow elastic body 22 may abut against each other.

As shown in FIG. 3A, the shaft rod 32 penetrates the pair of pressure plates 30 in the thickness direction (vertical direction). One end and the other end of the shaft rod 32 are joined to the housing 20 and are supported by the housing 20. In addition, a restricting portion 36 that defines the movement range of the pressure plate 30 is provided at each end of the shaft rod 32. The restricting portion 36 is provided on all shaft rods 32. The restricting portion 36 is a cylindrical member formed with a diameter larger than the insertion hole 30a (see FIG. 3B), and is fixed to the shaft rod 32 by a method such as caulking, screwing, or welding. Since the restricting portion 36 cannot pass through the insertion hole 30a of the pressure plate 30, the movement range of the pressure plate 30 in the vertical direction is restricted by the restricting portion 36. In this embodiment, the restricting portion 36 abuts against the housing 20.

Between the pair of pressure plates 30, a return mechanism 26 is provided to return the pressure plates 30 and the hollow elastic body 22 to their initial positions. In this embodiment, the return mechanism 26 is made of a coil spring and is spanned between the pair of opposing pressure plates 30. The return mechanism 26 exerts a pulling force to bring the pair of pressure plates 30 closer to each other by elastic restoring force. The return mechanism 26 is disposed in a position where it does not interfere with the expanded hollow elastic body 22 near the shaft rod 32. The installation of the return mechanism 26 is not limited to between the pair of pressure plates 30. The return mechanism 26 may be disposed on the outside of each of the pair of pressure plates 30. In this embodiment, the return mechanism 26 is provided in four pieces, the same as the shaft rods 32. The return mechanism 26 is not limited to a coil spring, and may be made of an elastic material such as rubber.

The function of the pressure relief member 10 of this embodiment will now be described.

As shown in FIG. 4, when no pressure is applied, the hollow elastic body 22 is cylindrical with a diameter similar to that of the tube 106, and is in an initial, unexpanded state. The pair of pressure plates 30 that sandwich the hollow elastic body 22 are biased toward each other by the pulling force of the return mechanism 26, and are kept in contact with a portion of the outer circumferential surface of the hollow elastic body 22.

As shown in FIG. 5, when the pressure of the infusion fluid in the flow path 22a inside the hollow elastic body 22 increases, the hollow elastic body 22 expands. The hollow elastic body 22 expands according to the internal pressure, expanding as if pushing apart the pair of pressure plates 30. The expansion of the hollow elastic body 22 relieves the pressure acting on the connector 12, preventing leakage of the infusion fluid from the connector 12 and damage to the connector 12 and catheter assembly 104.

The expansion of the hollow elastic body 22 is restricted by the pressure plate 30 abutting against the restricting portion 36. If only the hollow elastic body 22 is provided without the expansion restricting mechanism 24, the hollow elastic body 22 may expand too much and burst, or may be difficult to restore to its original state. In contrast, in this embodiment, the expansion restricting mechanism 24 restricts the expansion of the hollow elastic body 22, thereby preventing damage to the hollow elastic body 22. In addition, the return mechanism 26 can encourage the hollow elastic body 22 to return to its initial state through the pressure plate 30, making it easy to respond to repeated increases in pressure.

The pressure relief member 10 of this embodiment is configured as described above, and its function will be explained below.

The pressure relief member 10, connector 12, and infusion tube set 100 of this embodiment have the following effects:

The pressure relief member 10 of this embodiment is connected to an infusion line (e.g., tube 106) to allow the drug solution in the infusion line to flow, and is equipped with a hollow elastic body 22 that elastically deforms and expands in response to the pressure in the infusion line, an expansion restriction mechanism 24 that contacts the outer surface of the hollow elastic body 22 to restrict the expansion of the hollow elastic body 22, and a return mechanism 26 that promotes the return of the hollow elastic body 22 to its original shape from its expanded state.

The pressure relief member 10 configured as described above can mitigate sudden pressure increases in the infusion line by expanding the hollow elastic body 22. In addition, by restricting the expansion of the hollow elastic body 22 with the expansion restriction mechanism 24, it is possible to prevent the hollow elastic body 22 from expanding to a diameter that would cause permanent distortion and make it impossible to restore, thereby preventing damage to the hollow elastic body 22. Furthermore, the return mechanism 26 can encourage the hollow elastic body 22 to return to its initial shape, making it possible to respond to repeated increases in pressure.

In the above pressure relief member 10, the expansion restriction mechanism 24 may have a pressing portion (e.g., a pressing plate 30) that contacts the hollow elastic body 22 so as to sandwich it. With this configuration, the expansion of the hollow elastic body 22 can be restricted, thereby preventing damage to the hollow elastic body 22.

In the above pressure relief member 10, the pressing portion may have a pair of pressing plates 30 arranged opposite each other. With this configuration, the pressing plates 30 are in surface contact with the outer periphery of the hollow elastic body 22 and can regulate excessive expansion of the hollow elastic body 22, thereby preventing damage to the hollow elastic body 22.

In the above pressure relief member 10, the expansion restriction mechanism 24 may have a restriction portion 36 that restricts the maximum movable range of the pressing portion (pressing plate 30). With this configuration, excessive expansion of the hollow elastic body 22 can be restricted, thereby preventing damage to the hollow elastic body 22.

In the above pressure relief member 10, the expansion restriction mechanism 24 has an axial rod 32 that penetrates the pressing portion (pressing plate 30) and guides the displacement direction of the pressing portion, and the restricting portion 36 is provided on the axial rod 32. With this configuration, the restricting portion 36 can restrict the displacement range of the pressing portion by restricting movement along the axial rod 32.

The pressure relief member 10 may further include a housing 20 that covers the expansion restriction mechanism 24, and the restriction portion 36 may be fixed to the housing 20.

In the above pressure relief member 10, the return mechanism 26 may be made of an elastic body. More specifically, it may be a coil spring stretched between a pair of pressure plates 30.

In the above pressure relief member 10, the return mechanism 26 is provided on the hollow elastic body 22 side of the pressing portion (e.g., the pressing plate 30), and may be composed of an elastic member (e.g., rubber or a coil spring) that applies tension to the pressing portion.

The connector 12 of this embodiment includes the above-mentioned pressure relief member 10 and a connector body 13 that can be connected to a catheter (catheter assembly 104) placed in a blood vessel 114, and the pressure relief member 10 is integrally provided on the base end side of the connector body 13. The connector 12 of this configuration can protect the connector body 13 from damage caused by a sudden increase in pressure.

The connector 12 of this embodiment may have a male luer portion 15 on the connector body portion 13 that is connected to the catheter assembly 104.

In this embodiment, the connector 12 can connect a tube 106 to the base end side of the connector body 13 via a pressure relief member 10.

The infusion tube set 100 of this embodiment includes the above-mentioned pressure relief member 10, a connector body 13 connectable to a catheter assembly 104 placed in a blood vessel 114, and a tube 106 connected to the base end side of the connector body 13, and the connector body 13 and the tube 106 are connected via the pressure relief member 10. With this configuration, the pressure relief member 10 can prevent leakage and damage of the connector 12 and the catheter assembly 104.

Second Embodiment
As shown in Fig. 6, the pressure relief member 10A of this embodiment differs from the pressure relief member 10 of Fig. 3A in the configuration of the pressing plate 30A. Note that in the pressure relief member 10A of this embodiment, the same components as those in the pressure relief member 10 of Fig. 3A are denoted by the same reference numerals and detailed descriptions thereof will be omitted.

As shown in the figure, the pressure relief member 10A of this embodiment also constitutes an expansion restriction mechanism 24 that restricts the expansion of the hollow elastic body 22 by sandwiching the hollow elastic body 22 from above and below with a pressure plate 30A. However, the pressure plate 30A of this embodiment is separated in the center in the axial direction (longitudinal direction), and is separated into a tip portion and a base portion. In other respects, it is the same as the pressure relief member 10 of FIG. 3A.

The pressure relief member 10A of the present embodiment described above also provides the same effect as the pressure relief member 10 of FIG. 3A. In addition, the pressure relief member 10A is easier to assemble than the pressure relief member 10 because the pressure plate 30A is separated in the center. Also, the area where the pressure plate 30A presses the hollow elastic body 22 is smaller than that of the pressure plate 30, so the hollow elastic body 22 is more likely to deform in response to an instantaneous increase in pressure. This improves pressure relief performance (response speed). In addition, the pressure plate 30A is not limited to being separated in the center, and may be composed of a perforated plate such as a mesh or a punched plate.

Third Embodiment
As shown in Fig. 7, the pressure relief member 10B of this embodiment differs from the pressure relief member 10 of Fig. 3A in the shaft rod 32B and the restricting portion 36B of the expansion restricting mechanism 24. Note that in the pressure relief member 10B of this embodiment, the same components as those in the pressure relief member 10 of Fig. 3A are denoted by the same reference numerals and detailed descriptions thereof will be omitted. Also, the housing 20 is not shown in Fig. 7.

In this embodiment, the shaft rod 32B has a thread groove 40 formed on the outer periphery. Although not particularly limited, the thread groove 40 may be formed over the entire range of the shaft rod 32B. Restricting portions 36B are provided near both ends of the shaft rod 32B. The restricting portions 36B have a screw structure that can be screwed into the thread groove 40. The position of the restricting portions 36B can be adjusted by rotating the restricting portions 36B around the shaft rod 32B.

As described above, in this embodiment, the position of the restricting portion 36B on the shaft rod 32B can be adjusted by the screw mechanism. Therefore, with the pressure relief member 10B of this embodiment, the range in which the pressure plate 30 can be displaced can be adjusted as needed.

Fourth Embodiment
As shown in Figures 8A and 8B, the pressure relief member 10C of this embodiment differs from the pressure relief member 10 of Figure 3A in the pressing plate 30C and the shaft rod 32C. In the pressure relief member 10C of this embodiment, the same components as those of the pressure relief member 10 of Figure 3A are denoted by the same reference numerals and detailed descriptions thereof will be omitted. Also, in Figures 8A and 8B, the housing 20 is not shown.

As shown in FIG. 8A, the pressure relief member 10C has a structure in which the hollow elastic body 22 is sandwiched between a pair of pressure plates 30C1 and 30C2. The pressure plates 30C1 and 30C2 extend in a direction perpendicular to the plane of the drawing and abut the outer periphery of the hollow elastic body 22. One end of the pressure plate 30C1 is rotatably connected to the shaft rod 32C via a hinge 42. The other pressure plate 30C2 is rotatably connected to the shaft rod 32C via a hinge 44.

The first connecting plate 48 is rotatably connected to the other end of the pressure plate 30C1 via a hinge 46. The second connecting plate 52 is rotatably connected to the other end of the pressure plate 30C2 via a hinge 50. Furthermore, the first connecting plate 48 and the second connecting plate 52 are rotatably connected by a hinge 54. The rotation axes of the hinges 42, 44, 46, 50, and 54 are oriented perpendicular to the paper surface of the figure. The first connecting plate 48 and the second connecting plate 52 regulate the displacement range of the pressure plates 30C1 and 30C2. That is, the expansion restriction mechanism 24 of this embodiment includes the first connecting plate 48 and the second connecting plate 52 connected by the hinges 46, 50, and 54.

A return mechanism 26C made of a coil spring (elastic member) is spanned between the pair of pressure plates 30C1 and 30C2. The return mechanism 26C is provided near the first connection portion 22b and near the second connection portion 22c of the hollow elastic body 22 (see FIG. 3A), and is positioned so as not to interfere with the expanded hollow elastic body 22.

The action of the pressure relief member 10C will be described below. In the initial state, the tension (elastic restoring force) of the return mechanism 26C displaces the other end of the pressure plate 30C1 and the other end of the pressure plate 30C2 so that they approach each other, and the outer circumferential surface of the hollow elastic body 22 abuts against the pair of pressure plates 30C1 and 30C2. When pressure acts on the hollow elastic body 22 and the hollow elastic body 22 expands, the other ends of the pressure plates 30C1 and 30C2 are pushed apart as shown in FIG. 8B. Accordingly, the first connecting plate 48 and the second connecting plate 52 open. As shown in the figure, when the first connecting plate 48 and the second connecting plate 52 are fully extended, the pressure plates 30C1 and 30C2 do not open any further. At that time, the pressure plates 30C1 and 30C2 become approximately parallel. That is, the movable range of the pressure plates 30C1, 30C2 is restricted by the first connecting plate 48 and the second connecting plate 52. The distance between the pressure plates 30C1, 30C2, which defines the expandable range of the hollow elastic body 22, is determined by the distance between the hinges 42, 44 and the length of the first connecting plate 48 and the second connecting plate 52.

When the pressure in the hollow elastic body 22 decreases, the hollow elastic body 22 and the pressure plates 30C1 and 30C2 return to their initial positions due to the action of the return mechanism 26C. The pressure relief member 10C of this embodiment described above can relieve a sudden increase in pressure, similar to the pressure relief member 10 of the first embodiment. Furthermore, the pressure relief member 10C reduces the number of parts and makes assembly easier.

Fifth Embodiment
As shown in Figures 9A and 9B, the pressure relief member 10D of this embodiment is generally similar to the pressure relief member 10C, but differs from the pressure relief member 10C shown in Figure 8A in the pressing plate 30D. Note that in the pressure relief member 10D of this embodiment, the same components as those in the pressure relief member 10C of Figure 8A are denoted by the same reference numerals and detailed descriptions thereof will be omitted. Also, the housing 20 is not shown in Figures 9A and 9B.

As shown in FIG. 9A, the pressure relief member 10D has a structure in which the hollow elastic body 22 is sandwiched between a single pressure plate 30D. The pressure plate 30D is bent at a bending portion 56, and one end and the other end are attached to the shaft rod 32C through an insertion hole 58. The pressure plate 30D is made of a plate-like member extending in a direction perpendicular to the paper surface of the figure. The pressure plate 30D is made of a flexible resin sheet such as polyethylene resin, polypropylene resin, or polyethylene terephthalate resin. The pressure plate 30D is attached to the shaft rod 32C so that it can slide freely through the insertion hole 58.

A return mechanism 26C consisting of a coil spring (elastic member) is suspended between one end and the other end of the pressure plate 30D. The return mechanism 26C is provided near the shaft rod 32 and is positioned so as not to interfere with the expanded hollow elastic body 22. In the initial state, the pressure plate 30D is shaped in the bent shape shown in the figure, and can be restored to its initial state by the elastic restoring force of the pressure plate 30D alone.

The action of the pressure relief member 10D will be described below. In the initial state, the tension (elastic restoring force) of the return mechanism 26C displaces one end of the pressure plate 30D so that the other end approaches each other, and the outer circumferential surface of the hollow elastic body 22 abuts against the pair of pressure plates 30D. When pressure acts on the hollow elastic body 22 and the hollow elastic body 22 expands, the one end of the pressure plate 30D is pushed apart so that the other end is separated, as shown in FIG. 9B. As shown, when the pressure plate 30D abuts against the restricting portion 36, the pressure plate 30D will not open any further. As a result, the expansion of the hollow elastic body 22 is restricted by the pressure plate 30D.

When the pressure in the hollow elastic body 22 decreases, the hollow elastic body 22 is pushed back by the pressure plate 30D due to the action of the return mechanism 26C, and the hollow elastic body 22 returns to its initial shape.

The pressure relief member 10D of this embodiment described above can relieve a sudden increase in pressure, similar to the pressure relief member 10 of the first embodiment. In addition, the pressure relief member 10D reduces the number of parts and makes assembly easier.

The present invention has been described above with reference to preferred embodiments, but it goes without saying that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention.

10, 10A, 10B, 10C, 10D... Pressure relief member 12... Connector 13... Connector body 20... Housing 22... Hollow elastic body 24... Expansion restriction mechanism 26, 26C... Return mechanism 30, 30A, 30C, 30D... Pressing plate 32, 32B, 32C... Shaft rod 36, 36B... Restriction part 100... Infusion tube set 106... Tube 112... Catheter

Claims (8)

a hollow elastic body that communicates with an infusion line to allow a medicinal solution in the infusion line to flow and that elastically deforms and expands in response to a pressure in the infusion line;
an expansion restriction mechanism that restricts the expansion of the hollow elastic body by contacting an outer surface of the hollow elastic body;
a return mechanism for facilitating the return of the hollow elastic body from its expanded state to its original shape;
Equipped with
The expansion restriction mechanism includes:
A pair of pressure plates arranged opposite to each other and abutting against each other so as to sandwich the hollow elastic body;
A shaft that passes through the pressure plate and guides the pressure plate in a displacement direction;
a restricting portion provided at one end and the other end of the shaft rod for restricting a maximum movable range of the pressure plate;
Equipped with
The shaft rod has a screw groove on an outer periphery thereof,
The restricting portion has a thread structure that screws into the thread groove,
A pressure relief member , wherein the position of the restriction portion is adjustable by the screw groove and the screw structure . 2. The pressure relief member according to claim 1 , further comprising a housing that covers the expansion restriction mechanism, the restriction portion being fixed to the housing. 3. The pressure relief member according to claim 1 , wherein the return mechanism is made of an elastic material. 4. The pressure relief member according to claim 1, wherein the return mechanism is comprised of an elastic member that is spanned between a pair of the pressure plates and applies tension to the pair of pressure plates so as to bring them closer to each other . A pressure relief member according to any one of claims 1 to 4 ,
a connector main body connectable to a catheter placed in a blood vessel,
The pressure relief member is integrally provided on a base end side of the connector body. 6. The connector according to claim 5 , wherein the connector body has a male luer portion for connection to the catheter. 7. The connector according to claim 5 , wherein an infusion tube is connectable to a base end side of the connector body through the pressure relief member. A pressure relief member according to any one of claims 1 to 4 ,
a connector body connectable to a catheter placed in a blood vessel;
an infusion tube connected to a base end side of the connector main body,
The infusion tube set includes the connector body and the infusion tube connected via the pressure relief member.

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