Needle assembly

Abstract

To provide a needle assembly having high operation stability when a needle tip protector is disengaged.SOLUTION: A needle assembly 100 comprises: an outer needle unit 101; an inner needle unit 102; a connector cap 103 that is detachably assembled; and a needle tip protector 104 that is held by the connector cap 103, accommodates a needle tip of the inner needle, and is detached from the connector cap 103 together with the inner needle unit 102. The needle tip protector 104 has: a closing part 143 that relatively moves radially inward when the needle tip is accommodated and closes a tip-side needle hole so that it cannot be opened; and a protector-side engaging part 145 that releases the engagement with the connector cap 103 by the relative movement of the closing part 143. The protector-side engaging part 145 has a pin member that is integrated with the closing part 143 and is detached from a cap-side engaging part at a closing position.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a needle assembly, and more particularly to an indwelling needle having a safety mechanism for protecting the needle tip after use. [Background technology]

[0002] In dialysis treatment and the like, an indwelling needle may be inserted and left in a blood vessel. When inserting an indwelling needle, a needle assembly is used in which an inner needle, which is a puncture needle, is inserted into an outer needle, which is an indwelling needle. After the needle assembly is inserted into a blood vessel, the indwelling needle can be left in place by removing the inner needle. To prevent accidental punctures with the removed inner needle, a needle tip protector that houses the tip of the removed inner needle is commonly incorporated into the needle assembly.

[0003] For example, a needle tip protector has been considered that has a cylindrical case and a closing member that closes the tip of the case (see, for example, Patent Document 1). Because the pulled-out needle tip is stored in the case, it is possible to prevent accidental touching of the needle tip and splashing of blood adhering to the needle tip. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-93184 Summary of the Invention [Problem to be solved by the invention]

[0005] The needle tip protector is required to be held by the outer needle hub so as not to move with the movement of the inner needle until the needle tip is retracted, and to be able to smoothly detach along with the inner needle after the needle tip is retracted. Therefore, some kind of engagement mechanism is required to hold the needle tip protector stationary at the base end of the outer needle hub and release the hold when the needle tip is retracted. For example, in Patent Document 1, a locking claw that engages with the outer surface of the outer needle hub is provided as the engagement mechanism. When the inner needle is retracted into the needle tip protector and the closure member is activated, the locking claw that was engaged with the outer surface of the outer needle hub moves outward and disengages from the outer needle hub. However, with such a configuration, it is necessary to ensure space outside the outer needle hub to allow the locking claw to move. This raises the risk that the locking claw may come into contact with the operator's fingers or the patient's skin, preventing the locking claw from moving outward.

[0006] An engagement mechanism that engages with the inside of the outer needle hub is also possible, but if it complies with the ISO standards established for medical device connectors, there is little design freedom and it is difficult to ensure operational stability.

[0007] An object of the present disclosure is to realize a needle assembly that has high operational stability when disengaging a needle tip protector. [Means for solving the problem]

[0008] One aspect of the needle assembly of the present disclosure comprises an outer needle unit having an outer needle and an outer needle hub provided at the proximal end of the outer needle and having a connecting portion provided at the proximal end; an inner needle unit having an inner needle inserted into the outer needle and an inner needle hub provided at the proximal end of the inner needle; a connector cap removably attached to the connecting portion of the outer needle; and a needle tip protector that is held by the connector cap, contains the needle tip of the inner needle that has been removed from the outer needle, and is detached from the connector cap together with the inner needle unit, the needle tip protector comprising: a cylindrical case through which the inner needle is inserted through a distal needle hole and a proximal needle hole; and a needle tip protector that is disposed within the case in a state biased towards the inserted inner needle, and that moves radially inward relative to the inner needle when the needle tip moves more proximal than the distal needle hole. The connector has a closure section that closes the tip-side needle hole so that it cannot be opened, and a protector-side engagement section that disengages from the connector cap when the closure section moves relative to the connector, and the closure section is arranged in an open position on the opposite side of the tip-side needle hole to a first magnetic body fixed to the tip section of the case, and has a second magnetic body that slides to a closed position that closes the tip-side needle hole and becomes magnetically attached to the first magnetic body when the needle tip of the inner needle moves toward the base end from the tip-side needle hole, and the protector-side engagement section has a pin member that is integrated with the closure section, and in the open position, the pin member passes through a pin insertion hole formed in the case and is inserted into a cap-side engagement section formed in the connector cap, and in the closed position, it detaches from the cap-side engagement section.

[0009] In one aspect of the needle assembly, the needle tip protector is held by a connector cap detachably attached to the outer needle hub, and the pin member of the protector-side engaging portion is inserted into a cap-side engaging portion formed in the connector cap through a pin insertion hole formed in the case in the open position, and detached from the cap-side engaging portion in the closed position. Because the needle tip protector is configured to engage and disengage with the connector cap, the closing portion and the protector-side engaging portion can be enlarged without being restricted by size or other conditions. This allows for the strength of the closing portion and the protector-side engaging portion and the operation of the needle tip protector to be stabilized. Furthermore, because the protector-side engaging portion is configured to move inward, the movement of the protector is not hindered by fingers or the like, improving operational stability.

[0010] In one aspect of the needle assembly, the case can have a guide wall that guides the sliding of the closing part to the closed position. This configuration allows the second magnetic body integrated with the pin member to slide smoothly, improving the interlocking between the closing of the distal needle hole and the release of the engagement.

[0011] In one aspect of the needle assembly, the case has a cylindrical case body that is open at the tip end and a case cap that closes the opening of the case body, and the pin insertion hole is formed by a notch formed in the open end of the case body and a surface on the base end side of the case cap. With this configuration, the pin insertion hole can be easily formed and the pin member integrated with the second magnetic body can be easily inserted into the pin insertion hole.

[0012] In one aspect of the needle assembly, the connector cap has a holding portion on the base end side that holds the needle tip protector, and the holding portion has a pair of notches that elastically deform radially outward so that the needle tip protector can be inserted from the base end side with the pin member protruding from the pin insertion hole. This configuration allows the assembled needle tip protector to be easily held in the connector cap. Unlike the outer needle hub to which the connector is connected in a liquid-tight manner, the connector cap can easily be made of a member that is easily elastically deformable so that it can easily accept the needle tip protector.

[0013] In one aspect of the needle assembly, the closing portion, when in the open position, abuts against the periphery of the pin insertion hole in the case to prevent the pin member from falling out of the pin insertion hole. With this configuration, the closing portion acts as an anchor, preventing the closing portion and the pin member from falling out of the pin insertion hole.

[0014] Furthermore, at least one of the connector cap and the needle tip protector can have an indicator for aligning the needle tip protector with the connector cap when the needle tip protector is held by the connector cap. With this configuration, when the needle tip protector is held by the holding part, the protector side engaging part and the cap side engaging part can be easily engaged.

[0015] In one aspect of the needle assembly, the cap-side engagement portion can be a through-hole. Unlike the outer needle hub to which the connector is fluid-tightly connected, a through-hole can be formed in the connector cap, making it possible to easily engage with the pin member. It is possible. [Effects of the Invention]

[0016] According to the needle assembly of the present disclosure, the operational stability when disengaging the needle tip protector can be greatly improved. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of a needle assembly in a usable state. [Figure 2] 2 is an enlarged cross-sectional view showing the vicinity of a needle tip protector in FIG. 1. FIG. [Figure 3] FIG. 10 is a cross-sectional view illustrating a needle assembly in a separated state according to one embodiment. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing the vicinity of a needle tip protector in FIG. 3. [Figure 5] FIG. 2 is a plan view showing the inside of the tip surface of the needle tip protector. DETAILED DESCRIPTION OF THE INVENTION

[0018] As shown in Figures 1 and 2, one embodiment of the needle assembly 100 comprises an outer needle unit 101 having an outer needle 111 and an outer needle hub 112 provided at the base end of the outer needle 111, an inner needle unit 102 having an inner needle 121 and an inner needle hub 122 provided at the base end of the inner needle 121, a connector cap 103 attached to the base end of the outer needle hub 112, and a needle tip protector 104 held by the connector cap 103.

[0019] The outer needle 111 is a hollow needle made of resin etc. The inner needle 121 is a puncture needle made of metal etc. and has a sharp needle tip 123. The outer diameter of the inner needle 121 is approximately the same as the inner diameter of the outer needle 111.

[0020] The base end of the outer needle hub 112 forms a connection part 171 to which a connector is connected, and the tip side of the connector cap 103 is provided with an assembly part 151 that is removably assembled to the connection part 171. In this embodiment, the connection part 171 is a female luer connector, and the assembly part 151 is a male luer connector having a male luer part 151a and a collar 151b. The base end side of the connector cap 103 is provided with a holding part 153 that holds the needle tip protector 104. In this embodiment, the inner needle hub 122 is housed in the holding part 153 in a usable state.

[0021] When the inner needle hub 122 is grasped and pulled toward the base end, the inner needle 121 is pulled out of the outer needle 111, and the needle tip 123 enters a protected state housed in the needle tip protector 104. As shown in Figures 3 and 4, when the inner needle hub 122 is pulled further toward the base end, the needle tip protector 104, which houses the needle tip 123, enters a separated state in which it is detached from the holding portion 153 of the connector cap 103.

[0022] The needle tip protector 104 has a cylindrical case 141, and a protector-side engaging portion having a closing portion 143 and a pin member 145 is housed inside the case 141. The case 141 has a distal needle hole 161 and a proximal needle hole 162, and in a usable state, the inner needle 121 extends through the proximal needle hole 162 and the distal needle hole 161.

[0023] The base end needle hole 162 is formed slightly smaller than the tip end needle hole 161. A stopper with a larger diameter than the rest of the inner needle 121 is formed proximally of the needle tip 123 of the inner needle 121. The stopper is formed so that it can pass through the tip end needle hole 161 but cannot pass through the base end needle hole 162. When the inner needle 121 is pulled out proximally, the stopper reaches the base end needle hole 162, and the inner needle 121 cannot move relative to the needle tip protector 104. The distance from the needle tip 123 to the stopper is shorter than the length of the case 141, so when the stopper reaches the base end needle hole 162, the needle tip 123 is located proximally of the tip end needle hole 161 and is housed within the case 141.

[0024] The closing part 143 is movable from an open position where it does not overlap with the tip-side needle hole 161 to a closed position where it blocks the tip-side needle hole 161. When the inner needle 121 is inserted through the tip-side needle hole 161, the movement of the closing part 143 to the closed position is restricted by the inner needle 121. In the present embodiment, the closing part 143 is a second magnetic body (movable magnetic body) made of a magnet or a hard magnetic body, etc., and when the inner needle 121 has passed through the tip-side needle hole 161, it is urged toward the inner needle 121 by a first magnetic body (fixed magnetic body) 147 made of a magnet or a hard magnetic body, etc., fixed inside the case 141 on the opposite side of the tip-side needle hole 161. As shown in Figures 3 and 4, when the needle tip 123 of the inner needle 121 moves proximally beyond the distal needle hole 161, it is no longer restricted by the inner needle 121, and the closing portion 143, which is a second magnetic body, slides radially inward toward the first magnetic body 147 and reaches a closed position where it closes the distal needle hole 161. At the closed position, the closing portion 143 is magnetically attached to the first magnetic body 147 and is fixed in the closed position so that the distal needle hole 161 will not be opened again. Note that although an example has been shown in which the entire closing portion 143 is made of a magnetic body, it is also possible for only a portion of the closing portion 143 to be made of a magnetic body. For example, a magnetic body can be fixed to a resin molded body by adhesive or the like, or the resin molded body and the magnetic body can be molded integrally by insert molding, or a soft magnetic body can be used as the magnetic body.

[0025] The protector-side engaging portion has a pin member 145 that is integrated with the closing portion 143. The pin member 145 is inserted into a pin insertion hole 146 that penetrates the side wall surface of the case 141 on an extension of a straight line connecting the first magnetic body 147 and the tip-side pinhole 161. The pin member 145 is longer than the pin insertion hole 146, and when the closing portion 143 is in the open position, the pin member 145 penetrates and protrudes through the pin insertion hole 146 formed in the side surface of the case 141. A cap-side engaging portion 155 that is a through-hole is formed in the holding portion 153 of the connector cap 103, and the portion of the pin member 145 that protrudes from the case 141 is inserted into the cap-side engaging portion 155. When the closing portion 143 moves from the open position to the closed position, the pin member 145 also moves radially inward together with the closing portion 143 so that it no longer protrudes from the case 141 and is released from the cap side engaging portion 155 .

[0026] When the closing portion 143 is in the open position, as shown in FIG. 2, the pin member 145 of the protector-side engaging portion is engaged with the cap-side engaging portion 155, so that the needle tip protector 104 is fixed to the holding portion 153. This prevents the needle tip protector 104 from detaching from the holding portion 153 before the needle tip 123 is housed in the needle tip protector 104 and reaches a protected state. As shown in FIG. 4, when the needle tip 123 of the inner needle 121 moves proximally beyond the distal needle hole 161 and reaches a protected state, the closing portion 143 moves from the open position to a closed position on the radially inner side, so that the pin member 145, which interlocks with the closing portion 143, also moves radially inward. As a result, the pin member 145 disengages from the cap-side engaging portion 155 and the engagement is released, so that the needle tip protector 104 can be detached from the holding portion 153 with almost no resistance and placed in a separated state.

[0027] The pin member 145 of the protector-side engaging portion can be molded integrally with the closing portion 143. For example, the closing portion 143 and the pin member 145 can be formed integrally using a magnetic material such as a magnet. Furthermore, if a portion of the closing portion 143 is made of resin, the resin portion of the closing portion 143 and the pin member 145 can be molded integrally. The pin member 145, molded separately from the closing portion 143, can also be fixed to the closing portion 143 by adhesive or the like.

[0028] The pin member 145 of the protector-side engagement portion protruding from the case 141 engages with a cap-side engagement portion 155 provided on the holding portion 153 of the connector cap 103. In this embodiment, the cap-side engagement portion 155 is a through-hole into which the pin member 145 is inserted, but it may be a non-through recess or have various other configurations that can engage with the pin member 145. When the cap-side engagement portion 155 is a through-hole, it is preferable that the inserted pin member 145 does not protrude from the outer surface of the connector cap 103 when the closing portion 143 is in the closed position, so that fingers and the like do not get caught. However, a protruding configuration is also possible.

[0029] As shown in FIG. 5 , in this embodiment, a guide slot 148 is provided inside the case 141 to facilitate sliding movement of the closing portion 143. The guide slot forming member 148a that forms the guide slot 148 has two columnar portions formed on both sides of the distal needle hole 161, thereby restricting left-right movement of the closing portion 143. The guide slot forming member 148a also has a wall member on the proximal end surface of the closing portion 143 to restrict movement of the closing portion 143 toward the proximal end. Therefore, the closing portion 143 moves linearly from the open position to the closed position without significant wobble. Since wobble of the pin member 145 of the protector-side engaging portion that moves together with the closing portion 143 is also suppressed, the pin member 145 can be smoothly disengaged from the cap-side engaging portion 155. Note that the restriction of movement of the closing portion 143 toward the proximal end can also be achieved by a configuration other than the guide slot 148.

[0030] In this embodiment, the guide slot 148 is a tunnel-shaped space provided at the tip end of the case 141, and guides the movement of the closing part 143. The movement of the closing part 143 in the width direction and the front-rear direction is restricted, and the closing part 143 moves while being guided in the sliding direction. The guide slot 148 can be formed by a guide slot forming member 148a molded integrally with the tip end surface of the case 141, but it can also be formed by adhering a separate member, for example.

[0031] In this embodiment, case 141 is formed by a cylindrical case body 141a having an opening at the tip end, and a case cap 141b that closes the opening of case body 141a. Guide slot 148 is formed in case cap 141b. With this configuration, closure part 143 can be assembled to the guide slot 148 portion of case cap 141b before it is attached to case body 141a, making manufacturing easier. Note that the guide slot may be formed in the case body, or the guide slot may be formed by the case body and the case cap.

[0032] Two slide ribs can be provided on the inner surface of guide slot 148 along the sliding direction of closing part 143. By providing the slide ribs, the contact area between closing part 143 and case cap 141b is reduced, allowing closing part 143 to move more smoothly. However, a configuration without slide ribs is also possible.

[0033] In this embodiment, the pin insertion hole 146 is formed by a notch formed at the tip of the case main body 141a and the base end surface of the case cap 141b. With this configuration, the pin insertion hole 146 is formed by attaching the case cap 141b, to which the closing portion 143 integrated with the pin member 145 is attached, to the case main body 141a, and the pin member 145 is inserted into the pin insertion hole 146, making manufacturing easier.

[0034] In this embodiment, the tip of case body 141a is not a perfect circle but is a substantially elliptical shape with linear portions. This limits the direction in which case cap 141b can be attached to case body 141a, making it easier to align closing portion 143 with the notch that becomes pin insertion hole 146. The shape of the tip is not limited to a two-fold rotationally symmetric shape such as an elliptical shape, and it can also be an asymmetric shape or a more symmetrical shape such as a perfect circle.

[0035] In this embodiment, case cap 141b is fixed to case main body 141a by a fixed snap fit in which hooks 165 formed on case main body 141a engage with holes 166 formed in case cap 141b. This configuration makes it possible to easily fix case cap 141b to case main body 141a. However, fixing case main body 141a and case cap 141b can be performed using various methods.

[0036] As shown in FIG. 5 , in this embodiment, the pin member 145 protrudes from the closing portion 143 along the sliding direction of the closing portion 143. By configuring the pin member 145 to protrude from the closing portion 143, it is easy to form the closing portion 143 and the pin member 145 into an integrated unit that can move as a single unit. The width W3 of the pin member 145, which is perpendicular to the sliding direction and the axial direction, is slightly shorter than the width W2 of the pin insertion hole 146, and the width W1 of the closing portion 143 is longer than W2 and W3. Therefore, in the open position, the closing portion 143 abuts against the peripheral edge of the pin insertion hole 146 in the case 141, preventing the pin member 145 from slipping out of the pin insertion hole 146. Instead of increasing the width of the entire closing portion 143, only a portion of the closing portion 143 may be made wider than the width of the pin insertion hole 146. Furthermore, the pin member 145 may be provided with an enlarged diameter portion or tapered to prevent the pin member 145 from falling out of the pin insertion hole 146 .

[0037] While Fig. 5 shows a configuration in which the wide closing portion 143 prevents the pin member 145 from falling out, the closing portion 143 and the pin member 145 may also be formed into a flat or rod-like shape with a constant width. In this case, after assembling the case 141 and inserting the inner needle 121, the closing portion 143 integrated with the pin member 145 can be inserted through the pin insertion hole 146, making manufacturing easier. By increasing the force of attraction between the first magnetic body 147 and the closing portion 143, the closing portion 143 and the pin member 145 inserted into the pin insertion hole 146 can be easily prevented from falling out. Furthermore, the cap-side engaging portion 155 may be formed as a blind hole to prevent the closing portion 143 and the pin member 145 from falling out after assembly.

[0038] It is preferable that the length L3 of the pin member 145 in the sliding direction is slightly longer than the length (sliding length) L2 from the open position to the closed position. By doing so, it is possible to prevent the pin member 145 from slipping out inward from the pin insertion hole 146 at the closed position. However, it is also possible to make the pin member 145 slip out inward from the pin insertion hole 146 at the closed position.

[0039] The length L1 of the closing portion 143 in the sliding direction is preferably approximately equal to the length of a perpendicular line extending from the distal needle hole 161 toward the pin insertion hole 146. This allows the closing portion 143 to be precisely sandwiched between the inner needle 121 and the inner surface of the case 141 in the closed position, preventing significant rattle. Furthermore, the length L1 and width W1 of the closing portion are preferably greater than the inner diameter φ1 of the distal needle hole 161. This allows the closing portion 143 to close the distal needle hole 161 in the closed position, reducing the risk of the needle tip 123 being re-exposed. However, a gap large enough to prevent the needle tip 123 from passing through is acceptable. Furthermore, it is preferable that the length L1 be longer than the sliding length L2 of the closing portion 143 from the viewpoint of closing the distal needle hole 161 in the closed position.

[0040] In this embodiment, the diameter of the case 141 is larger on the distal end side than on the proximal end side. By making the distal end side of the case 141 larger in diameter, it is possible to ensure space for incorporating the closing part 143 and the first magnetic body 147 and to prevent the overall size from increasing. From the viewpoint of ensuring space for incorporating the closing part 143 and the first magnetic body 147 and ensuring stable operation of the closing part 143, the outer diameter on the distal end side is preferably at least about 3 to 5 times the outer diameter of the inner needle 121, and from the viewpoint of preventing the needle tip protector 104 from becoming larger, it is preferably no more than about 10 to 12 times.

[0041] In the present embodiment, the holding portion 153 of the connector cap 103 has an inner diameter that is approximately the same as the outer diameter of the needle tip protector 104. The holding portion 153 has a plurality of axially extending slits 156, which allows it to be elastically deformed radially outward relatively easily. Therefore, after the needle tip protector 104 is assembled to the inner needle unit 102, the needle tip protector 104, with the pin member 145 of the protector-side engaging portion protruding from the case 141, can be easily inserted into the holding portion 153 to engage the pin member 145 with the cap-side engaging portion 155. This greatly improves manufacturing efficiency.

[0042] The holding portion 153 and the needle tip protector 104 may be provided with indicators for alignment. For example, the holding portion 153 and the needle tip protector 104 may be provided with indicators such as arrows, and when the needle tip protector 104 is inserted into the holding portion 153 while aligning the arrows, the pin member 145 automatically engages with the cap side engagement portion 155. Various indicators that allow alignment may be used, not just arrows. Alignment is facilitated if there is an indicator on at least one of the holding portion 153 and the needle tip protector 104. Furthermore, a guide may be provided as an indicator, allowing the needle tip protector 104 to be inserted into the holding portion 153 only at a specific position. For example, a notch and a protrusion may be provided, and when these are aligned, the needle tip protector 104 is inserted into the holding portion 153 and the pin member 145 automatically engages with the cap side engagement portion 155. Both an indicator and a guide may be provided.

[0043] The needle tip protector 104 can be engaged with the inner needle hub 122, and then the inner needle hub 122 can be placed over the outside of the holding part 153 while the needle tip protector 104 is inserted into the holding part 153. In this case, an indicator such as a mark or guide for engaging the needle tip protector 104 and the inner needle hub 122 in a predetermined positional relationship, and an indicator such as a mark or guide for engaging the inner needle hub 122 and the holding part 153 in a predetermined positional relationship can be provided. Also, a mechanism can be provided to prevent the needle tip protector 104 from rotating relative to the inner needle hub 122 when the needle tip protector 104 is engaged with the inner needle hub 122.

[0044] The inner surface of the connecting portion 171 provided at the base end of the outer needle hub 112 is smooth so as to achieve a liquid-tight connection with the connector on the tube side. Forming a hole or recess that engages with the pin member 145 on the inner surface while achieving liquid-tightness is not impossible, but requires high processing precision. Since the connector cap 103 is detached from the outer needle hub 112 when used as an indwelling needle, the shape of the inner surface is not limited, and it is therefore easy to form the cap side engaging portion 155, which is a through-hole or recess that engages with the pin member 145. Furthermore, unlike the outer needle hub 112, it is easy to form a slit or other means to enable elastic deformation radially outward, so that the needle tip protector 104 with the pin member 145 protruding can easily be held by the holding portion 153. The holding portion 153 can also be formed from a relatively flexible material to facilitate elastic deformation of the holding portion 153.

[0045] In the present embodiment, the inner needle hub 122 is fitted onto the holding part 153. This configuration prevents the position of the inner needle unit 102 from being unintentionally shifted. However, the inner needle hub 122 can also be engaged with the holding part 153 by a method other than fitting. It can also be engaged with a connector cap 103 other than the holding part 153. In the present embodiment, the needle tip protector 104 is firmly held in the holding part 153, so the inner needle hub 122 can also be engaged with the needle tip protector 104.

[0046] When the inner needle hub 122 is fitted onto the holding portion 153, the inner needle hub 122 can also be configured to cover the through-hole that is the cap side engaging portion 155. In this way, the pin member 145 and the cap side engaging portion 155 can be hidden, thereby preventing the user from trying to forcibly release the engagement.

[0047] In this embodiment, the assembly part 151 on the tip side of the connector cap 103 is a male luer connector having a male luer part 151a and a collar 151b, but it can have various configurations that allow it to be detachably connected to the connection part 171. In this embodiment, the male luer part 151a is formed thin so as not to press the plunger 176 housed in the outer needle hub 112.

[0048] In this embodiment, the outer needle hub 112 has a connecting portion 171 provided on the base end side, an outer needle fixing portion 174 provided on the tip end side for fixing the outer needle 111, and a flexible tube 173 connecting between the connecting portion 171 and the outer needle fixing portion 174.

[0049] In this embodiment, the proximal end of the connecting portion 171 is a female luer connector to which a male luer connector can be connected. The distal end of the connecting portion 171 houses a valve body 175 and a plunger 176 for opening the valve body 175. When the connector cap 103 is removed and a male connector is connected to the connecting portion 171, the plunger 176 is pushed toward the distal end by the male connector, opening the valve body 175. A plunger guide for smoothly moving the plunger 176 may be provided within the outer needle hub 112. The plunger 176 may be configured to move toward the proximal end when the male connector is pulled out, thereby closing the valve body 175 again, or it may be configured to remain at the distal end even when the male connector is pulled out, thereby maintaining the valve body 175 in an open state. The valve body 175 may be a slit valve.

[0050] The flexible tube 173 that connects the connecting part 171 and the outer needle fixing part 174 is made of soft resin. By providing the flexible tube 173, it is possible to prevent the movement of the connecting part 171 from being directly transmitted to the outer needle, making it easier to connect and disconnect the connector to the connecting part 171. It is also possible to improve the degree of freedom in the placement of the connecting part 171. It is also possible to clamp the flexible tube 173 and prevent the flow of liquid. However, it is also possible to configure the connecting part 171 and the outer needle fixing part 174 as one unit without providing the flexible tube 173.

[0051] The outer needle 111 can be formed into a hollow needle shape with appropriate flexibility. For example, the outer needle 111 can be formed from various soft resins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyurethane, polyetheramide, or polypropylene. Furthermore, one or more through-holes may be provided in the tip of the outer needle 111 as necessary to allow efficient circulation of fluid to the outer needle 111. The outer needle 111 can be fixed to the outer needle hub 112 by fitting, crimping, fusion, or bonding with an adhesive.

[0052] The inner needle 121 is a hollow needle and can be made of known materials such as stainless steel, aluminum, titanium, or alloys containing these. The needle tip 123 provided at the distal end of the inner needle 121 may be tapered so that the outer diameter gradually decreases toward the tip, allowing for easy insertion into a living body with minimal irritation.

[0053] The inner needle hub 122 provided at the rear end of the inner needle 121 has a substantially cylindrical base portion to which the rear end of the inner needle 121 is fixed in an embedded state, a substantially cylindrical cover portion that protrudes from the tip of the base portion and fits externally onto the outer wall of the holding portion 153, and a substantially cylindrical connector portion that protrudes from the rear end of the base portion. The inner needle 121 can be fixed to the inner needle hub 122 by fitting, crimping, fusion, bonding with an adhesive, or the like. The rear end of the inner needle 121 is exposed at the rear end of the base portion, and the lumen of the inner needle 121 communicates with the internal space of the connector portion. The inner needle hub 122 can be a resin molded product in which the base portion, cover portion, and connector portion are integrated. If the inner needle hub 122 is transparent or translucent so that the interior can be seen, it becomes possible to check for blood flashback.

[0054] The inner needle cap 105 can be detachably attached to the opening of the connector portion of the inner needle hub 122. A breathable filter can be provided at the opening of the inner needle cap 105. The breathable filter may be a filter that allows gas to pass through but blocks liquid. For example, a sintered porous body, a hydrophobic nonwoven fabric, or other porous body can be used.

[0055] Although an example has been shown in which the closing part 143 abuts against the inner needle 121 in the open position, the closing part 143 may also be configured not to abut against the inner needle 121 in the open position. For example, a cylindrical member can be provided between the inner needle 121 and the closing part 143, and the cylindrical member can be moved together with the inner needle 121 to prevent the closing part 143 from abutting against the inner needle 121. Such a configuration allows the inner needle 121 to be pulled out more smoothly. [Industrial Applicability]

[0056] The needle assembly of the present disclosure has high operational stability when disengaging the needle tip protector, and is useful in the medical field and the like. [Explanation of symbols]

[0057] 100 needle assembly 101 Outer needle unit 102 Inner needle unit 103 Connector cap 104 Needle Tip Protector 105 Inner needle cap 111 Outer needle 112 outer needle hub 121 Inner needle 122 Inner needle hub 123 Needle tip 141 cases 141a Case body 141b Case cap 143 Closure 145 Pin member 146 Pin insertion hole 147 First Magnetic Material 148 Guide Slot 151 Assembly section 151a Male lure part 151b color 153 Holding part 155 Cap side engagement part 156 Slit 161 Distal needle hole 162 Proximal needle hole 165 Hook 166 Hole 171 Connection 173 Flexible Tube 174 Outer needle fixing part 175 Valve body 176 Pusher

Claims

1. an outer needle unit having an outer needle and an outer needle hub provided at the base end of the outer needle and having a connection portion at the base end; an inner needle unit having an inner needle inserted through the outer needle and an inner needle hub provided at a proximal end of the inner needle; a connector cap removably attached to the connection portion of the outer needle; a needle tip protector that is held by the connector cap, that accommodates the needle tip of the inner needle that has been removed from the outer needle, and that is detached from the connector cap together with the inner needle unit, The needle tip protector has a cylindrical case into which the inner needle is inserted through a distal needle hole and a proximal needle hole, a closing part that is disposed in the case while being biased toward the inserted inner needle, and that moves radially inward relative to the case when the needle tip moves toward the proximal side from the distal needle hole to close the distal needle hole so that it cannot be opened, and a protector-side engaging part that is disengaged from the connector cap when the closing part moves relative to the case. the closing portion is disposed at an open position on the opposite side of the tip-side needle hole with respect to a first magnetic body fixed to the tip portion of the case, and has a second magnetic body that slides to a closed position where it closes the tip-side needle hole when the needle tip of the inner needle moves toward the base end side from the tip-side needle hole and is magnetically attracted to the first magnetic body; the protector-side engaging portion has a pin member integrated with the closing portion, In the open position, the pin member passes through a pin insertion hole formed in the case and is inserted into a cap side engaging portion formed in the connector cap, and in the closed position, the pin member is detached from the cap side engaging portion.

2. 2. The needle assembly of claim 1, wherein the case has a guide wall that guides the closure as it slides to the closed position.

3. The case has a cylindrical case body with an opening at the tip end and a case cap that closes the opening of the case body, 2. The needle assembly according to claim 1, wherein the pin insertion hole is defined by a notch formed in the open end of the case body and a surface of the base end side of the case cap.

4. the connector cap has a holding portion on a base end side that holds the needle tip protector, 2. The needle assembly according to claim 1, wherein the holding portion has a pair of notches at a base end, and elastically deforms radially outward to allow the needle tip protector to be inserted from the base end side with the pin member protruding from the pin insertion hole.

5. 2. The needle assembly according to claim 1, wherein the closing portion, in the open position, abuts against a peripheral edge of the pin insertion hole in the case to prevent the pin member from falling outward from the pin insertion hole.

6. 2. The needle assembly of claim 1, wherein at least one of the connector cap and the needle tip protector has an indicator for aligning the needle tip protector with the connector cap when the needle tip protector is held by the connector cap.

7. The needle assembly according to claim 1 , wherein the cap-side engagement portion is a through-hole.

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