Drug solution administration device

The drug solution administration device addresses the limitation of fixed needle placement by using a detachable needle hub and flexible tube configuration, enhancing user flexibility and convenience.

WO2026053512A1PCT designated stage Publication Date: 2026-03-12TERUMO KK
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Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Filing Date
2025-05-28
Publication Date
2026-03-12

AI Technical Summary

Technical Problem

Existing drug solution administration devices require the user to maintain constant pressure on the housing to insert the puncture needle, limiting the flexibility in needle placement.

Method used

A drug solution administration device with a detachable needle hub connected by a flexible tube, allowing the needle hub to be separated from the unit body, and a trigger mechanism that enables controlled ejection of the drug solution.

Benefits of technology

Enhances the freedom of needle placement by allowing the needle hub to be positioned independently of the device body, improving user convenience and flexibility.

✦ Generated by Eureka AI based on patent content.

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Abstract

A puncture unit (18) of a drug solution administration device (10A) comprises a unit body (182) and a needle hub (183) that holds a puncture needle (181) and that can be separated from the unit body (182). The puncture unit (18) further comprises a flexible tube (184) that couples the unit body (182) to the needle hub (183). The flexible tube (184) connects the puncture needle (181) and a connection needle (421) of a connection part (42). When the needle hub (183) is separated from the unit body (182), an intermediate part (603) of the flexible tube (184) is exposed to the outside of a housing (12).
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Description

Medical solution administration device

[0001] The present disclosure relates to a drug solution administration device.

[0002] Japanese Patent No. 6154061 discloses a drug solution administration device. The drug solution administration device includes a cylindrical casing and a syringe housed inside the casing and filled with drug solution. When a user administers drug solution, the user presses the tip of the casing against the skin, causing a puncture needle to protrude from the tip of the casing and puncture the skin, and the drug solution in the syringe is then administered subcutaneously by the puncture needle.

[0003] Patent No. 6154061

[0004] In a medicinal solution administration device such as that disclosed in Japanese Patent No. 6154061, the patient must continue to press the housing against the skin while the puncture needle punctures the skin, which limits the position at which the puncture needle can be inserted. Therefore, there is a demand for greater flexibility in the placement position of the needle hub (puncture needle) relative to the living body when using the medicinal solution administration device.

[0005] The present disclosure aims to solve the above-mentioned problems.

[0006] (1) An aspect of the present disclosure is a drug solution administration device comprising: a housing; a syringe having a cylindrical body that is housed within the housing and filled with a drug solution; a puncture needle that administers the drug solution into a living body; and a puncture unit provided at the tip of the housing and having a connection part that can communicate with the inside of the cylindrical body by connecting to the tip of the syringe, wherein the puncture unit has a unit main body having the connection part; a needle hub that is detachable from the unit main body, holds the puncture needle, and is placed on the surface of the living body; and a flexible tube that connects the unit main body and the needle hub and communicates between the connection part and the puncture needle, wherein when the needle hub is detached from the unit main body, at least a portion of the flexible tube is exposed to the outside of the housing.

[0007] According to this medicinal solution administration device, the needle hub holding the puncture needle can be separated from the unit body, which effectively increases the freedom of the needle hub's placement position relative to the living body when using the medicinal solution administration device.

[0008] (2) In the drug solution administration device described in (1) above, the flexible tube may be accommodated in a bent state inside the housing, and the flexible tube may extend when the needle hub is separated from the unit body.

[0009] With this configuration, the flexible tube can be stored in a compact state within the housing, and the needle hub can be freely positioned by effectively extending the flexible tube when exposed to the outside of the housing.

[0010] (3) In the drug solution administration device described in (1) or (2) above, the flexible tube may be wound around and housed in the unit body.

[0011] This configuration allows the flexible tube to be housed efficiently within the housing while saving space.

[0012] (4) In the drug solution administration device described in any one of (1) to (3) above, the syringe has a sealing member that liquid-tightly seals the tip end of the cylindrical body, the connection portion has a connecting needle that can penetrate the sealing member of the syringe and a needle support member that supports the connecting needle, and the flexible tube may connect the connecting needle and the puncture needle.

[0013] With this configuration, the connection between the puncture needle and the syringe can be effectively maintained by the flexible tube even when the puncture unit and the needle hub are separated.

[0014] (5) The drug solution administration device according to (4) above, further comprising: a trigger member that moves relative to the housing in a proximal direction by being pressed against the living body to be punctured; a plunger that is provided inside the housing and is movable relative to the syringe in a distal direction as the trigger member moves relative to the housing in the proximal direction, and that ejects the drug solution from the puncture needle by moving in the distal direction; and a holding member that is provided inside the housing and holds the puncture unit, wherein, in an initial position of the trigger member, the connecting part is not connected to the distal end part of the syringe, and the trigger member covers the distal end part of the puncture unit, and when the trigger member performs a first operation of moving relative to the housing from the initial position in the proximal direction toward a first position that is provided further proximal from the initial position, the connecting needle penetrates the sealing member to communicate with the interior of the cylindrical body, and the trigger member moves toward a second position that is provided further proximal from the first position, and when a second action of relative movement from the first position in the proximal direction relative to the housing is performed, or when a third action of relative movement from the second position in the distal direction relative to the housing is performed toward a third position provided in the distal direction from the second position, the plunger moves relative to the syringe in the distal direction, and the trigger member has an engagement structure that engages the needle hub and the holding member with each other to prevent relative axial movement between the needle hub and the holding member at the initial position and the first position of the trigger member, the engagement structure including an elastic portion that is provided on the holding member and is elastically deformable radially outward, and an inner trigger wall of the trigger member faces the elastic portion at the initial position and the first position of the trigger member, thereby preventing release of engagement by the engagement structure, and at the second position of the trigger member, the elastic portion and the inner trigger wall do not face each other, and the elastic portion deforms radially outward, thereby releasing engagement by the engagement structure.

[0015] With this configuration, when the trigger member is in the second position, the engagement of the needle hub with the holding member can be released, thereby effectively separating the holding member from the needle hub of the pricking unit.

[0016] According to the present disclosure, by making it possible to separate a needle hub having a puncture needle from a unit main body having a connection portion that can be connected to a syringe, it is possible to effectively increase the degree of freedom in the placement position of the needle hub relative to the living body when using a drug solution administration device.

[0017] FIG. 1 is an external perspective view of a drug solution administration device according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view of the drug solution administration device shown in FIG. 1. FIG. 3 is a cross-sectional view of the distal end of the drug solution administration device shown in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a cross-sectional explanatory view showing the initial position of the drug solution administration device. FIG. 6 is an explanatory view showing the drug solution administration device during a first operation. FIG. 7 is an explanatory view showing the drug solution administration device at a first position. FIG. 8 is an external perspective view of a puncturing unit. FIG. 9 is an external perspective view of a holding member and a puncturing unit. FIG. 10 is an explanatory view showing the drug solution administration device during a second operation. FIG. 11 is an explanatory view showing the drug solution administration device at a second position. FIG. 12 is an explanatory view showing the drug solution administration device during a third operation. FIG. 13 is an explanatory view showing the puncturing unit indwelling at the third position of the drug solution administration device. FIG. 14A is an explanatory view showing drug solution administration by the drug solution administration device. Fig. 14B is an explanatory diagram showing administration of a medicinal solution by a medicinal solution administration device according to a modified example. Fig. 15 is a cross-sectional view of a distal end portion of a medicinal solution administration device according to a second embodiment of the present disclosure. Fig. 16 is an explanatory diagram showing a case where a puncture unit of the medicinal solution administration device shown in Fig. 15 is placed.

[0018] As shown in FIG. 1, a medicinal solution administration device 10A according to the first embodiment is used, for example, to administer a medicinal solution R subcutaneously to a patient C (living body, see FIG. 6) who is a user.

[0019] As shown in Figure 2, the drug solution administration device 10A comprises a housing 12, a trigger member 14 that is movable relative to the housing 12, a syringe 16 housed inside the trigger member 14, a puncturing unit 18 that can puncture the skin S (see Figure 6) of a patient C (see Figure 6), a holding member 20 that holds the puncturing unit 18, and a plunger 22 provided inside the housing 12.

[0020] The housing 12 is formed of a resin material in a hollow cylindrical shape and has a main body 121 extending axially (in the direction of arrows A and B), a slide member 122 housed on the base end side (in the direction of arrow A) of the main body 121, and an end cap 123 that closes the base end of the main body 121. A syringe 16 is housed inside the housing 12.

[0021] The main body 121 is cylindrical and elongated in the axial direction (the direction of arrows A and B). The main body 121 has an opening at its distal end and proximal end. As shown in FIG. 1 , the main body 121 has a window 124 in its peripheral wall. The user can check the medicinal solution R in the syringe 16 from outside the housing 12 through the window 124 (see FIG. 2 ).

[0022] As shown in FIG. 2 , in the medicinal solution administration device 10A before use, a tip cap 24 is attached to the housing 12. As shown in FIG. 3 , the tip cap 24 is formed in a cylindrical shape with a bottom and engages with the tip portion of the housing 12. A protective cover 26 that covers the tip of the puncture needle 181 is held in the center of the tip cap 24. In the medicinal solution administration device 10A before use, the tip cap 24 covers the trigger member 14 and the tip of the housing 12. When using the medicinal solution administration device 10A, the tip cap 24 can be removed from the tip portion of the housing 12 (see FIG. 5 ). By removing the tip cap 24 from the housing 12, the protective cover 26 is removed together with the tip cap 24, exposing the tip of the puncture needle 181 (see FIG. 5 ).

[0023] Trigger member 14 is displaced relative to housing 12 in the proximal direction (direction of arrow A) when pressed against skin S (the target to be punctured) of patient C (see FIG. 10 ). Trigger member 14 is movably disposed inside main body 121 of housing 12. Trigger member 14 is configured as needle cover 14A that can house puncturing unit 18.

[0024] Trigger member 14 includes a cylindrical trigger body 141, a pair of cover portions 142 extending from trigger body 141 in the proximal direction (direction of arrow A), and a pair of extension portions 143 extending from the proximal end of cover portions 142. Trigger member 14 is biased toward the distal end by the resilient force of spring member 28 via slide member 122. In the initial state before use of chemical solution administration device 10A, the distal end of trigger member 14 protrudes distally (direction of arrow B) beyond the distal end of housing 12. In the initial position of trigger member 14, trigger member 14 covers the distal end of lancing unit 18.

[0025] As shown in Figure 3, trigger body 141 is formed at the tip of trigger member 14. Trigger body 141 has an opening 30. Opening 30 is formed in the center of the tip of trigger body 141 and passes through trigger member 14 in the axial direction. When trigger member 14 moves relative to housing 12 in the proximal direction, puncture needle 181 of puncture unit 18 can be inserted into opening 30 (see Figure 11).

[0026] 5, the pair of cover portions 142 are spaced apart from each other in the circumferential direction of the trigger member 14. A pair of slits 32 is provided between the pair of cover portions 142. Each slit 32 extends from the trigger body 141 toward the proximal end.

[0027] As shown in Fig. 4, the pair of cover portions 142 have a plurality of trigger inner walls 34. Each of the plurality of trigger inner walls 34 protrudes radially inward from each of the pair of cover portions 142. The plurality of trigger inner walls 34 are spaced apart from one another along the circumferential direction of the cover portions 142. Each of the plurality of trigger inner walls 34 is disposed spaced apart from the distal end toward the proximal end of the trigger body 141. Each of the plurality of trigger inner walls 34 extends along the axial direction of the trigger body 141 (see Fig. 5).

[0028] 2 , the syringe 16 is fixed inside the housing 12. The syringe 16 is fixed inside the housing 12 via a syringe holder 36 fixed inside the main body 121. The syringe 16 does not move relative to the housing 12 in the axial direction. The syringe 16 includes a cylindrical body 161, a sealing member 162, and a stopper 163.

[0029] The cylindrical body 161 is made of a transparent resin material. The cylindrical body 161 is a hollow body formed in a substantially cylindrical shape with an open base end. The cylindrical body 161 has a chamber 164 filled with a medicinal liquid R. The medicinal liquid R may be used, for example, for subcutaneous injection of a user (patient C). The cylindrical body 161 has a flange 165 protruding radially outward at the outer periphery of the base end. The cylindrical body 161 has a tip holding portion 166 at its tip. The tip holding portion 166 has a reduced diameter from the cylindrical body 161 and protrudes toward the tip. As shown in FIG. 3 , the tip holding portion 166 has a hole 38 communicating with the chamber 164. The hole 38 penetrates in the axial direction of the syringe 16. A syringe cap 167 is attached to the tip holding portion 166. The syringe cap 167 covers the tip holding portion 166 of the cylindrical body 161. The cylindrical body 161 of the syringe 16 is held by the syringe holder 36 .

[0030] The sealing member 162 is made of an elastic material such as rubber. The sealing member 162 is held in the center of the syringe cap 167. The sealing member 162 covers the tip of the hole 38 in the cylindrical body 161. The sealing member 162 liquid-tightly seals the tip of the cylindrical body 161. The sealing member 162 seals the drug solution R in the drug chamber 164 in the cylindrical body 161.

[0031] As shown in FIG. 2 , stopper 163 is provided in chamber 164 of cylindrical body 161. Stopper 163 is provided so as to be movable toward the tip (direction of arrow B) along the axial direction of cylindrical body 161. Stopper 163 is slidably inserted into chamber 164 of cylindrical body 161. Stopper 163 is formed from an elastic material such as rubber. Stopper 163 is attached to the tip portion of plunger 22. Stopper 163 protrudes toward the tip portion of plunger 22. Stopper 163 is inserted from the base end of cylindrical body 161 into chamber 164 of cylindrical body 161. By inserting stopper 163 inside cylindrical body 161, the base end side of cylindrical body 161 is liquid-tightly sealed, and medicinal solution R in chamber 164 is enclosed inside cylindrical body 161.

[0032] As shown in FIG. 5, the puncturing unit 18 includes a puncturing needle 181, a unit body 182, a needle hub 183, and a flexible tube 184 connecting the unit body 182 and the needle hub 183.

[0033] The puncture needle 181 is provided so as to be able to administer the medicinal solution R subcutaneously to a patient C (see FIG. 6 ). The puncture needle 181 includes a hollow cylindrical outer needle 401 and an inner needle 402 that can be inserted into the outer needle 401. In other words, the puncture needle 181 is a double needle. The outer needle 401 is a hollow body having an internal flow path through which the medicinal solution R flows. The flow path of the outer needle 401 communicates with the drug chamber 164 of the cylindrical body 161 that is filled with the medicinal solution R.

[0034] The unit main body 182 includes a connecting part 42 and an intermediate member 44 disposed in the distal direction (direction of arrow B) of the connecting part 42. The connecting part 42 is formed so as to be able to communicate with the interior of the cylindrical body 161 by connecting to the distal end of the syringe 16. The connecting part 42 includes a connecting needle 421 and a needle support member 422 that supports the connecting needle 421.

[0035] The connecting needle 421 is formed to communicate with the puncture needle 181 and to be able to penetrate the sealing member 162 of the syringe 16. The connecting needle 421 is formed in a hollow cylindrical shape. The connecting needle 421 is provided in the center of the needle support member 422 and protrudes from the partition wall 46 of the needle support member 422 in the proximal direction (the direction of arrow A). The connecting needle 421 and the sealing member 162 of the syringe 16 face each other in the axial direction of the trigger member 14. When the trigger member 14 is in the initial position, the connecting needle 421 of the connection portion 42 is not connected to the tip end of the syringe 16 (see FIG. 3 ).

[0036] As shown in Figure 6, when the trigger member 14 moves relative to the housing 12 from the initial position toward a first position located proximal to the housing 12 (hereinafter referred to as the "first movement"), the connecting needle 421 penetrates the sealing member 162 and communicates with the chamber 164 of the cylindrical body 161 (see Figure 7).

[0037] 5, the needle support member 422 has a first recess 481 and a first tube connecting portion 501. The first recess 481 is provided toward the distal end of the partition portion 46 and opens toward the distal end. The distal end of the connecting needle 421 is provided in the first recess 481. The first tube connecting portion 501 communicates with the first recess 481 and opens radially outward from the needle support member 422. The flexible tube 184 is inserted into the first tube connecting portion 501.

[0038] The intermediate member 44 is provided between the connecting portion 42 and the needle hub 183. The intermediate member 44 is fixed to the distal end of the needle support member 422. The intermediate member 44 holds the proximal end of the inner needle 402 of the puncture needle 181. In other words, the intermediate member 44 is the inner needle hub 44a. The inner needle hub 44a is disposed in the proximal direction of the needle hub 183 (the direction of arrow A). The inner needle hub 44a is formed in a cylindrical shape. The inner needle hub 44a has an annular second recess 482 therein. A annular first magnet M1 is housed in the distal end of the second recess 482.

[0039] The outer peripheral surface of the inner needle hub 44a has a first accommodating groove 541 recessed radially inward. The first accommodating groove 541 is formed in the shape of a single spiral centered on the axis of the inner needle hub 44a (see FIG. 8 ).

[0040] The needle hub 183 is provided toward the tip of the unit body 182. The needle hub 183 is provided so as to be separable from the unit body 182 (see FIG. 13 ). The needle hub 183 holds the base end of the outer needle 401 of the puncture needle 181. In other words, the needle hub 183 is an outer needle hub that holds the outer needle 401. The tip of the needle hub 183 is perpendicular to the axial direction of the needle hub 183. A patch 56 is provided on the tip of the needle hub 183. The patch 56 is formed in a sheet shape and is attached so as to fit along the tip of the needle hub 183. The adhesive surface of the patch 56 is the surface opposite to the surface attached to the needle hub 183.

[0041] With the puncture needle 181 puncturing the skin S of the patient C, the tip of the needle hub 183 is placed on the skin S. At this time, the adhesive surface of the patch 56 abuts and is fixed on the surface of the skin S of the patient C (see FIG. 13 ). Note that the present invention is not limited to providing the patch 56 on the tip of the needle hub 183. For example, the tip of the needle hub 183 may be provided with a fixing structure (adsorption portion) that can be fixed to the skin S.

[0042] The needle hub 183 has a communication chamber 52 and a second tube connecting portion 502. The communication chamber 52 is provided in the center of the needle hub 183 and communicates with the base end of the outer needle 401. The second tube connecting portion 502 is formed in a tubular shape and extends radially outward from the needle hub 183. The second tube connecting portion 502 and the communication chamber 52 communicate with each other. A flexible tube 184 is connected to the second tube connecting portion 502.

[0043] An annular second magnet M2 and a cap 57 are provided at the base end of the needle hub 183. The second magnet M2 is covered by a hub cover 58, which will be described later, and is held by the needle hub 183. The first magnet M1 and the second magnet M2 are arranged coaxially in the axial direction of the puncture unit 18. The needle hub 183 and the inner needle hub 44a are connected to each other in the axial direction by the magnetic forces of the first magnet M1 and the second magnet M2. The cap 57 is formed in a plate shape from an elastic material such as rubber. The cap 57 covers the base end of the communicating chamber 52. The cap 57 liquid-tightly seals the communicating chamber 52.

[0044] A hub cover 58 is provided at the proximal end of the needle hub 183. The hub cover 58 covers the proximal end of the needle hub 183. The needle hub 183, hub cover 58, and inner needle hub 44a are arranged side by side in the axial direction of the puncture unit 18 toward the proximal end. The tip of the inner needle hub 44a faces the hub cover 58. The hub cover 58 has a through-hole 581 penetrating in the axial direction at its center. The inner needle 402 of the puncture needle 181 is inserted through the through-hole 581. The inner needle 402 penetrates the cap 57 of the needle hub 183. The hub cover 58 covers the second magnet M2 and the cap 57 of the needle hub 183. The outer peripheral surface of the hub cover 58 has a second housing groove 542 recessed radially inward. The second housing groove 542 is formed in the shape of a single spiral centered on the axis of the hub cover 58 (see FIG. 8 ). The first accommodating groove 541 of the inner needle hub 44 a and the second accommodating groove 542 of the hub cover 58 form one continuous spiral accommodating groove 54 .

[0045] The flexible tube 184 connects the unit main body 182 and the needle hub 183. The flexible tube 184 connects the connection needle 421 of the connection part 42 and the puncture needle 181. The flexible tube 184 is formed in a tubular shape from an elastically deformable material. The flexible tube 184 is shaped in a spirally wound state. Note that the flexible tube 184 is not limited to a spirally shaped configuration. For example, the flexible tube 184 may be formed in a non-spiral shape.

[0046] The tip 601 of the flexible tube 184 is connected to the second tube connecting portion 502 of the needle hub 183. The flexible tube 184 communicates with the communication chamber 52 of the needle hub 183 via the second tube connecting portion 502. The base end 602 of the flexible tube 184 is inserted into the first tube connecting portion 501 of the needle support member 422. The base end 602 of the flexible tube 184 is connected to the tip of the connecting needle 421 in the first recess 481. In other words, the flexible tube 184 connects the connecting needle 421 of the puncture unit 18 and the communication chamber 52 of the needle hub 183 to each other.

[0047] The flexible tube 184 is wound around the outer periphery of the unit main body 182 and is housed in a bent state inside the housing 12. The flexible tube 184 has an intermediate portion 603. The intermediate portion 603 is provided between the distal end 601 and proximal end 602 of the flexible tube 184. As shown in Figure 8, the intermediate portion 603 of the flexible tube 184 is wound and housed in the housing groove 54 that connects the first housing groove 541 of the inner needle hub 44a and the second housing groove 542 of the hub cover 58.

[0048] When the needle hub 183 is separated from the unit main body 182, at least a portion of the flexible tube 184 is exposed to the outside from the distal end of the housing 12. A portion of the flexible tube 184 protrudes from the housing 12 in the distal direction (the direction of arrow B) and is exposed, and an intermediate portion 603 of the flexible tube 184 extends (see FIG. 13 ).

[0049] The holding member 20 is provided inside the housing 12 and holds the puncture unit 18. As shown in Fig. 9 , the holding member 20 comprises a holder main body 201 and a pair of first arm portions 202. The holder main body 201 is formed in a cylindrical shape. As shown in Fig. 5 , the inner needle hub 44a, the hub cover 58, and the needle hub 183 are housed inside the holder main body 201. The base end of the holder main body 201 is provided with a pair of hooks 203 that protrude radially inward. The pair of hooks 203 engage with a pair of grooves 62 of the needle support member 422, respectively. The pair of hooks 203 engage with the holding member 20 and the needle support member 422, connecting them to each other.

[0050] 2, the plunger 22 has a cylindrical shape that is long in the axial direction. The plunger 22 is housed inside the housing 12 so as to be movable in the axial direction. The plunger 22 includes a cylindrical rod main body 221 and an attachment portion 222 formed at the tip of the rod main body 221. The stopper 163 of the syringe 16 is attached to the attachment portion 222.

[0051] An injection spring 64 is provided inside the rod main body 221. The injection spring 64 is provided between the distal end of the rod main body 221 and the end cap 123. The resilient force of the injection spring 64 urges the plunger 22 toward the distal end (direction of arrow B). Before use, in the medicinal solution administration device 10A, the plunger 22 is prevented from moving toward the distal end by a locking mechanism (not shown). As the trigger member 14 moves relative to the base end (second operation), the resilient force of the injection spring 64 allows the plunger 22 to move relative to the syringe 16 in the distal direction.

[0052] As shown in Fig. 1 , in the drug solution administration device 10A before use, a sealing cap 66 is further attached to the housing 12. The sealing cap 66 is removably provided at the tip of the main body 121 of the housing 12. As shown in Fig. 3 , the sealing cap 66 includes a cap main body 661, a first sealing member 681, and a second sealing member 682.

[0053] The cap body 661 is attached to the outer peripheral surface of the body 121. The cap body 661 is formed in an arc shape extending along the circumferential direction of the body 121 (see FIG. 1). The cap body 661 is inserted into a side wall opening 72 that opens into the peripheral wall of the body 121. The grip portion 70 is plate-shaped and protrudes radially outward from the outer peripheral surface of the cap body 661. When removing the sealing cap 66 from the housing 12, the user can grip the grip portion 70.

[0054] The first sealing member 681 and the second sealing member 682 are formed in a sheet shape and are provided inside the housing 12. The base ends of the first sealing member 681 and the second sealing member 682 are held on the inner circumferential surface of the cap body 661. The first sealing member 681 and the second sealing member 682 each protrude radially inward from the cap body 661. In the axial direction of the housing 12, the first sealing member 681 and the second sealing member 682 are spaced apart from each other and are generally parallel to each other.

[0055] In the medicinal solution administration device 10A before use, the tip end of the first sealing member 681 abuts against and is adhered to the end surface of the sealing member 162 of the syringe 16. The end surface of the sealing member 162 is covered by the first sealing member 681, thereby maintaining the sterilized state of the sealing member 162. In the medicinal solution administration device 10A before use, the tip end of the second sealing member 682 abuts against and is adhered to the base end of the needle support member 422. The base end of the needle support member 422 and the connecting needle 421 are covered by the second sealing member 682, thereby maintaining the sterilized state of the connecting needle 421.

[0056] When using the drug solution administration device 10A, the sealing cap 66 is removed from the housing 12, whereby the first sealing member 681 is peeled off from the sealing member 162 and the second sealing member 682 is peeled off from the needle support member 422. The first sealing member 681 and the second sealing member 682 are taken out of the housing 12 through the side wall opening 72.

[0057] As shown in FIG. 5, the drug solution administration device 10A further includes a first engagement structure 741, a second engagement structure 742, and a third engagement structure 743.

[0058] The first engagement structure 741 engages the housing 12 and the holding member 20 with each other when the trigger member 14 is in the first position (see FIG. 7 ). The first engagement structure 741 prevents relative axial movement between the housing 12 and the holding member 20 when the trigger member 14 is in the first position. The first engagement structure 741 includes a pair of first engagement portions 76 provided on the holding member 20, and a pair of second engagement portions 78 provided on the housing 12 and engaged with the pair of first engagement portions 76.

[0059] The pair of first engagement portions 76 respectively extend in the proximal direction from the proximal ends of the pair of first arm portions 202. Each first engagement portion 76 has a first engagement hole 761 that penetrates the first engagement portion 76 in the radial direction.

[0060] The pair of second engagement portions 78 are provided at the tip end of the syringe holder 36. Each second engagement portion 78 is disposed inside the first engagement portion 76 of the holding member 20. The pair of second engagement portions 78 protrude radially outward from the tip end of the syringe holder 36. When the trigger member 14 is in the first position, each second engagement portion 78 engages with the first engagement hole 761 of the corresponding first engagement portion 76. Due to the engagement between the first engagement portion 76 and the second engagement portion 78, the housing 12 and the holding member 20 do not move relative to each other in the axial direction.

[0061] The second engagement structure 742 engages the trigger member 14 and the holding member 20 with each other when the trigger member 14 is in the initial position. The second engagement structure 742 prevents relative axial movement between the trigger member 14 and the holding member 20 when the trigger member 14 is in the initial position. The second engagement structure 742 includes a first elastic portion 80 that is provided on the holding member 20 and is elastically deformable radially outward.

[0062] A pair of first elastic members 80 are provided on the holding member 20 radially outward of the holder main body 201. The base ends of the pair of first elastic members 80 are supported by the base end of the holder main body 201. Each of the pair of first elastic members 80 and the holder main body 201 are spaced apart from each other in the radial direction. The pair of first elastic members 80 are spaced apart from each other in the circumferential direction of the holding member 20. The pair of first elastic members 80 are provided such that their tip ends can tilt with the base ends as a fulcrum. The base end of each first elastic member 80 is a first fixed end 821 fixed to the holder main body 201. The tip end of each first elastic member 80 is a first free end 822.

[0063] The tip end of each first elastic portion 80 has a first abutment portion 84. The first abutment portion 84 protrudes radially inward from the tip end of each first elastic portion 80. The tip end of the first abutment portion 84 has an inclined portion 841 that inclines radially inward toward the base end. When the trigger member 14 is in the initial position, the first elastic portion 80 faces a housing inner wall 125 of the housing 12 (main body 121). The housing inner wall 125 is provided at the tip end of the main body 121. The housing inner wall 125 is disposed radially outward from the first elastic portion 80. The housing inner wall 125 restricts radially outward movement of the first elastic portion 80.

[0064] The second engagement structure 742 further includes second abutment portions 86. As shown in FIG. 4 , the second abutment portions 86 are provided on the pair of cover portions 142 of the trigger member 14. The second abutment portions 86 are provided on wall portions 88 that protrude from the cover portions 142 toward the slit 32. The second abutment portions 86 are provided on the base ends of the wall portions 88 (see FIG. 5 ). The second abutment portions 86 protrude from the wall portions 88 in the circumferential direction of the trigger member 14. The second abutment portions 86 are provided toward the distal end of the first abutment portions 84 of the holding member 20. The second abutment portions 86 are arranged to be able to abut against the first abutment portions 84 when the trigger member 14 moves toward the proximal end. The abutment between the first abutment portions 84 and the second abutment portions 86 maintains the axial engagement between the trigger member 14 and the holding member 20. The second engagement structure 742 prevents the trigger member 14 and the holding member 20 from moving relative to each other, and they move together.

[0065] The third engagement structure 743 engages the needle hub 183 and the retaining member 20 with each other when the trigger member 14 is in the initial position (see FIG. 5) and the first position (see FIG. 7). The third engagement structure 743 prevents relative axial movement between the needle hub 183 and the retaining member 20 when the trigger member 14 is in the initial position and the first position. The third engagement structure 743 includes a plurality of protrusions 90 provided on the needle hub 183 and a second elastic portion 92 provided on the retaining member 20 and elastically deformable radially outward.

[0066] As shown in Fig. 4, each of the multiple protrusions 90 is provided on the outer peripheral surface of the needle hub 183. The multiple protrusions 90 protrude radially outward from the outer peripheral surface of the needle hub 183. The multiple protrusions 90 are spaced apart from one another in the circumferential direction of the needle hub 183. Below, a case where three protrusions 90 are provided will be described.

[0067] As shown in Fig. 9, the second elastic portion 92 is provided at the tip end of the holder body 201 of the holding member 20. As shown in Fig. 4, the second elastic portion 92 has a plurality of second arm portions 921. Each of the plurality of second arm portions 921 is provided so as to be elastically deformable radially outward relative to the holder body 201. The plurality of second arm portions 921 are spaced apart from one another in the circumferential direction of the holder body 201. The number of second arm portions 921 is the same as the number of protrusions 90. Below, a case where three second arm portions 921 are provided will be described.

[0068] As shown in FIG. 9 , each second arm portion 921 extends in the circumferential direction of the holder main body 201. The second arm portion 921 includes a second fixed end 941 and a second free end 942. The second fixed end 941 is one end of the second arm portion 921 in the circumferential direction of the holder main body 201. The second fixed end 941 is fixed to the holder main body 201. When the second arm portion 921 elastically deforms in the radial direction, the second fixed end 941 serves as the starting point. The second free end 942 is the other end of the second arm portion 921 in the circumferential direction of the holder main body 201. The second free end 942 deforms radially outward relative to the holder main body 201 (see FIG. 12 ).

[0069] The second arm portion 921 has a second engagement hole 96 with which the protrusion 90 of the needle hub 183 can engage. The second engagement hole 96 is formed in the second free end 942. The second engagement hole 96 penetrates the second arm portion 921 in the radial direction of the holder body 201. When the protrusion 90 engages with the second engagement hole 96, relative movement in the axial direction between the holding member 20 and the needle hub 183 is prevented.

[0070] When the trigger member 14 is in the initial position and the first position, each second elastic portion 92 faces a corresponding trigger inner wall 34 of the trigger member 14 in the radial direction of the trigger member 14 (see FIG. 4 ). Each trigger inner wall 34 is disposed radially outward of each second elastic portion 92. Each trigger inner wall 34 prevents each second elastic portion 92 from moving radially outward, maintaining engagement between the protrusion 90 and the second engagement hole 96. Engagement between the needle hub 183 and the retaining member 20 by the third engagement structure 743 is maintained.

[0071] Next, administration of the medicinal liquid R by the medicinal liquid administration device 10A will be described.

[0072] First, in the drug solution administration device 10A before use shown in FIG. 2 , the tip cap 24 is removed from the housing 12 and the tip of the trigger member 14 (see FIG. 5 ). As shown in FIG. 5 , removing the tip cap 24 opens the housing 12 and the tip of the trigger member 14, and simultaneously removes the protective cover 26 covering the puncture needle 181. The sealing cap 66 is removed from the outer peripheral surface of the housing 12. By removing the sealing cap 66 radially outward from the housing 12, the first sealing member 681 and the second sealing member 682 are pulled radially outward by the sealing cap 66. This causes the first sealing member 681 to peel off from the sealing member 162, and the second sealing member 682 to peel off from the needle support member 422. The peeled first sealing member 681 and second sealing member 682 are each removed to the outside of the housing 12 through the sidewall opening 72 of the housing 12. The connecting needle 421 of the connecting portion 42 and the sealing member 162 of the syringe 16 face each other in the axial direction.

[0073] Next, the drug solution R is administered using the drug solution administration device 10A from which the tip cap 24 and the sealing cap 66 have been removed.

[0074] Before puncturing the drug solution administration device 10A, the trigger member 14 is in an initial position covering the tip of the puncturing unit 18. In the initial position of the trigger member 14, the tip of the syringe 16 and the connecting portion 42 are spaced apart in the axial direction, and the connecting needle 421 is not connected to the sealing member 162 of the syringe 16. In the initial position of the trigger member 14, the first elastic portion 80 of the holding member 20 and the housing inner wall 125 of the housing 12 face each other in the radial direction. Therefore, in the initial position, the first elastic portion 80 is prevented from deforming radially outward, and the trigger member 14 and the holding member 20 are engaged with each other. This prevents relative axial movement between the trigger member 14 and the holding member 20. A locking mechanism (not shown) prevents the plunger 22 from moving toward the tip.

[0075] As shown in Figure 6, the user grasps the housing 12 and presses the tip of the trigger member 14, which protrudes from the tip of the housing 12, against the skin S of the patient C, which will be the desired puncture site, at a substantially right angle. Next, the user continues to press the housing 12 toward the skin S (tip direction, direction of arrow B). As the housing 12 is pressed toward the skin S, the trigger member 14 is pressed by the skin S and moves relatively from the initial position toward the base end (direction of arrow A, first position). At this time, the trigger member 14 moves relatively to the housing 12 against the elastic force of the spring member 28.

[0076] 7 , when the trigger member 14 performs a first movement toward the first position relative to the housing 12, the second abutment portion 86 of the trigger member 14 abuts against the first abutment portion 84 of the holding member 20. The second abutment portion 86 of the trigger member 14 presses the first abutment portion 84 toward the proximal end, causing the lancing unit 18 to move toward the first position together with the trigger member 14.

[0077] At this time, the syringe 16 does not move relative to the housing 12. Movement of the puncturing unit 18 toward the proximal end (direction of arrow A) places the trigger member 14 in the first position, and the proximal end of the connecting needle 421 of the connecting part 42 punctures the sealing member 162 of the syringe 16. The connecting needle 421 penetrates the sealing member 162. This places the connecting needle 421 in communication with the chamber 164 of the syringe 16. At the first position, the tip of the second engaging part 78 is inserted into and engaged with the first engaging hole 761 of the first engaging part 76. This prevents relative axial movement of the holding member 20 and the puncturing unit 18 with respect to the housing 12 and the syringe holder 36.

[0078] 10 , the user moves the housing 12 further toward the skin S and further presses the tip of the trigger member 14 in the proximal direction. The trigger member 14 moves toward a second position that is located further proximally than the first position. Hereinafter, the movement of the trigger member 14 in the proximal direction from the first position to the second position will be referred to as the second movement.

[0079] When the trigger member 14 performs the second action, the holding member 20 does not move in the proximal direction because the first engagement structure 741 prevents the holding member 20 from moving relative to the housing 12. Therefore, the second action of the trigger member 14 causes the first elastic portion 80 of the holding member 20 and the housing inner wall 125 to move relative to each other in the axial direction, and the first elastic portion 80 and the housing inner wall 125 are positioned so that they do not face each other in the radial direction. This results in a state in which the first elastic portion 80 is positioned further proximally than the housing inner wall 125. This allows the first elastic portion 80 to deform radially outward.

[0080] A further second action of the trigger member 14 causes the second abutment portion 86 to push the first abutment portion 84 of the holding member 20 toward the proximal end, causing the inclined portion 841 of the first abutment portion 84 to abut against the second abutment portion 86, and the first free end 822 of the first elastic portion 80 is deformed radially outward via the inclined portion 841, with the first fixed end 821 as a fulcrum. The deformation of the first elastic portion 80 disengages the first engagement portion 76 from the second engagement portion 78. That is, in the second position, the prevention of relative movement between the trigger member 14 and the holding member 20 by the second engagement structure 742 is released, and the trigger member 14 and the holding member 20 become capable of relative axial movement.

[0081] As the trigger member 14 performs a second operation, the engagement by the second engagement structure 742 is released, and as shown in Fig. 11 , the trigger member 14 moves relative to the puncturing unit 18 in the proximal direction to the second position. When the trigger member 14 is in the second position, the puncturing needle 181 of the puncturing unit 18 protrudes distally from the opening 30 of the trigger member 14 (needle cover 14A). As a result, the tip of the puncturing needle 181 punctures the skin S and is inserted to a predetermined depth. The tip surface of the needle hub 183 abuts against the skin S, and the adhesive surface of the patch 56 is adhered to the surface of the skin S. As a result, with the puncturing needle 181 puncturing the skin S, the tip of the needle hub 183 is fixed to the surface of the skin S. The puncturing needle 181 has punctured the skin S of the patient C, resulting in a puncturing-completed state.

[0082] 12 , the second action of the trigger member 14 causes the trigger inner wall 34 to move relative to the second elastic portion 92 of the holding member 20 in the proximal direction (the direction of arrow A). As a result, when the trigger member 14 is in the second position, the second elastic portion 92 and the trigger inner wall 34 are spaced apart in the axial direction, and the second elastic portion 92 and the trigger inner wall 34 are not positioned opposite each other in the radial direction.

[0083] This allows the second elastic portion 92 to deform radially outward. The second free end 942 of the second elastic portion 92 (second arm portion 921) deforms radially outward with the second fixed end 941 as a fulcrum, thereby disengaging the protrusion 90 of the needle hub 183 from the second engagement hole 96 of the retaining member 20. That is, when the trigger member 14 is in the second position, the prevention of relative movement between the needle hub 183 and the retaining member 20 by the third engagement structure 743 is released, allowing the needle hub 183 and the retaining member 20 to move relative to each other in the axial direction.

[0084] After the puncture needle 181 has been inserted subcutaneously and the needle hub 183 has been fixed to the skin S at the second position of the trigger member 14, the user moves the medicinal solution administration device 10A (housing 12) away from the surface of the skin S of the patient C, which is the target of puncture, as shown in Fig. 13 . When the patient C releases the pressing force of the medicinal solution administration device 10A against the skin S, the trigger member 14 is urged toward the distal end (in the direction of arrow B) by the resilience of the spring member 28 (see Fig. 2 ). The trigger member 14 moves relative to the housing 12 from the second position toward a third position provided in the distal end direction. Hereinafter, the movement of the trigger member 14 when moving distally from the second position toward the third position will be referred to as the third movement.

[0085] Then, by moving the drug solution administration device 10A away from the surface of the skin S of the patient C, the needle hub 183 fixed to the skin S separates from the unit body 182. Specifically, when the unit body 182 moves away from the skin S together with the trigger member 14, the needle hub 183 is fixed to the skin S by the patch 56, so the magnetic force acting between the first magnet M1 and the second magnet M2 is separated, and the needle hub 183 remains fixed to the skin S. As the unit body 182 detaches from the needle hub 183, the inner needle 402 of the inner needle hub 44a is pulled out from the outer needle 401 of the needle hub 183. Only the outer needle 401 of the puncture needle 181 is left subcutaneously in the patient C.

[0086] At this time, the communication chamber 52 of the needle hub 183 is covered with the cap 57 and liquid-tightly sealed. That is, when the trigger member 14 is in the third position, the medical solution administration device 10A is separated into the needle hub 183 including the outer needle 401 to be placed in the skin S of the patient C, and the device main body 98 composed of everything other than the needle hub 183. At this time, the outer needle 401 of the needle hub 183 is separated from the unit main body 182, causing the flexible tube 184 connecting the needle hub 183 and the unit main body 182 to detach from the accommodating groove 54. The intermediate portion 603 of the flexible tube 184 extends spirally.

[0087] The third operation of trigger member 14 releases plunger 22 from the locking state of a locking mechanism (not shown). As shown in FIG. 2 , plunger 22 begins to move distally due to the resilient force of injection spring 64. As stopper 163 moves distally together with plunger 22, stopper 163 presses medicinal solution R in chamber 164 of syringe 16 distally. This causes medicinal solution R to flow from the distal end of syringe 16 through connecting needle 421 and flexible tube 184.

[0088] The medicinal solution R flows from the tip 601 through the intermediate portion 603 of the flexible tube 184 to the communication chamber 52 of the needle hub 183, and is then expelled subcutaneously into the patient C through the outer needle 401. This starts the administration of the medicinal solution R subcutaneously into the patient C. Note that the administration of the medicinal solution R by the plunger 22 is not limited to being started when the trigger member 14 performs the third action. For example, when the trigger member 14 performs the second action to puncture the puncture needle 181 into the skin S of the patient C, the plunger 22 may be moved in the tip direction to start the administration of the medicinal solution R.

[0089] When the trigger member 14 is in the third position, the tip of the trigger member 14 moves to a position in the device body 98 of the drug solution administration device 10A that is more distal than the tip of the inner needle 402. As a result, the inner needle 402 of the device body 98 is completely covered by the trigger member 14.

[0090] When the trigger member 14 is in the third position, a predetermined amount of medicinal liquid R in the chamber 164 of the syringe 16 is subcutaneously administered. After administration of the medicinal liquid R has begun, the user can store the separated device body 98 of the medicinal liquid administration device 10A in the housing 100, as shown in FIG. 14A . The housing 100 can store the device body 98, which is part of the medicinal liquid administration device 10A, and can be attached to the outside of the user's clothing, for example. By storing the device body 98 inside the housing 100 with the needle hub 183 indwelling on the user's skin S, the device body 98 can be held in a position close to the user's body. In other words, the user does not need to hold the device body 98 of the medicinal liquid administration device 10A during administration of the medicinal liquid R.

[0091] Instead of storing the device main body 98 in the housing 100 during administration of the medicinal solution R as described above, the device main body 98 may be held, as in the modified medicinal solution administration device 101 shown in FIG. 14B . This medicinal solution administration device 101 includes a hook member 102 on the exterior of the housing 12. The hook member 102 is L-shaped and protrudes radially outward from the outer circumferential surface of the housing 12, extending in the axial direction of the housing 12. By hooking the hook member 102 of the device main body 98 onto the user's pocket, the device main body 98 can be held on the user's body during administration of the medicinal solution R. In other words, the user does not need to hold the device main body 98 during administration of the medicinal solution R.

[0092] 13 , after a predetermined time has elapsed since the start of administration of medicinal solution R with trigger member 14 in the third position, patient C checks the position of stopper 163 in syringe 16 through window 124 (see FIG. 1 ) of housing 12. When all of medicinal solution R in syringe 16 has been administered, stopper 163 has moved to the tip of cylindrical body 161. When patient C confirms that stopper 163 has reached the tip of cylindrical body 161, it is confirmed that administration of medicinal solution R in syringe 16 has been completed.

[0093] After the subcutaneous administration of the medicinal solution R to the patient C is completed, the needle hub 183 is removed from the surface of the skin S. The used medicinal solution administration device 10A is disposed of in a predetermined manner.

[0094] The first embodiment has the following advantages.

[0095] 3, puncturing unit 18 of medical solution administration device 10A includes unit body 182 and needle hub 183 that holds puncturing needle 181 and is separable from unit body 182. Puncturing unit 18 further includes flexible tube 184 that connects unit body 182 and needle hub 183.

[0096] According to this configuration, the needle hub 183 holding the puncture needle 181 can be separated from the unit main body 182, thereby effectively increasing the degree of freedom in the placement position of the needle hub 183 relative to patient C (living body) when using the drug solution administration device 10A.

[0097] The flexible tube 184 is accommodated in a bent state inside the housing 12. As shown in Figure 13, when the needle hub 183 is separated from the unit body 182, the middle portion 603 of the flexible tube 184 stretches.

[0098] According to this configuration, the flexible tube 184 can be stored in a compact state inside the housing 12, and further, when the flexible tube 184 is exposed outside the housing 12, the needle hub 183 can be freely positioned by effectively stretching the flexible tube 184. Note that the flexible tube 184 is not limited to being stored in a bent state inside the housing 12. For example, the flexible tube 184 may be stored inside the housing 12 in an extended state.

[0099] 8, the flexible tube 184 is housed in a state where it is wound around the unit main body 182. With this configuration, the flexible tube 184 can be housed efficiently and in a space-saving manner inside the housing 12. Note that the flexible tube 184 is not limited to being housed in a state where it is wound around the unit main body 182. For example, the flexible tube 184 may be housed in a state where it is folded back multiple times around the outer periphery of the unit main body 182.

[0100] 7, the connecting part 42 has a connecting needle 421 that can penetrate the sealing member 162 of the syringe 16, and a needle support member 422 that supports the connecting needle 421. The connecting needle 421 and the puncture needle 181 communicate with each other through a flexible tube 184.

[0101] According to this configuration, the connection between the puncture needle 181 and the syringe 16 can be effectively maintained by the flexible tube 184 when the puncture unit 18 and the needle hub 183 are separated.

[0102] 12 , the device includes a trigger member 14 that moves relative to the housing 12 in the proximal direction when pressed against the skin S (the target to be punctured) of a patient C (living body). When the trigger member 14 is in the second position, the third engagement structure 743 (engagement structure) disengages the needle hub 183 from the holding member 20, thereby effectively separating the holding member 20 from the needle hub 183 of the puncture unit 18.

[0103] 15, a drug solution administration device 10B according to the second embodiment includes a puncturing unit 18B. The puncturing unit 18B includes a puncturing needle 181B and a needle hub 183B that holds the puncturing needle 181B.

[0104] 16, the puncture needle 181B is provided so as to be able to administer a medicinal solution R subcutaneously (inside the living body) of a patient C. The puncture needle 181B is formed in a hollow cylindrical shape. The puncture needle 181B is a single needle. The puncture needle 181B is held by a needle hub 183B.

[0105] When trigger member 14 performs the second action, trigger member 14 is placed in the second position, and puncture needle 181B of puncture unit 18B protrudes from the tip of trigger member 14 and punctures skin S. In response to the second action of trigger member 14, plunger 22 moves toward the tip relative to syringe 16. As plunger 22 moves toward the tip, medicinal solution R in chamber 164 is pushed toward the tip by stopper 163. Medicinal solution R in syringe 16 is administered subcutaneously to patient C through connecting needle 421, flexible tube 184 of needle coupling portion 60, and puncture needle 181B.

[0106] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

Claims

1. A drug solution administration device comprising: a housing; a syringe having a cylindrical body that is contained within the housing and filled with a drug solution; a puncture unit provided at the tip of the housing, the puncture needle for administering the drug solution into a living body, and a connection part that can communicate with the inside of the cylindrical body by connecting to the tip of the syringe, wherein the puncture unit has: a unit main body having the connection part; a needle hub that is detachable from the unit main body, holds the puncture needle, and is placed on the surface of the living body; and a flexible tube that connects the unit main body and the needle hub and communicates between the connection part and the puncture needle, wherein at least a part of the flexible tube is exposed to the outside of the housing when the needle hub is detached from the unit main body.

2. A drug solution administration device according to claim 1, wherein the flexible tube is accommodated in a bent state inside the housing, and when the needle hub is separated from the unit body, the flexible tube extends.

3. A drug solution administration device according to claim 2, wherein the flexible tube is wound around and housed in the unit body.

4. A drug solution administration device according to any one of claims 1 to 3, wherein the syringe has a sealing member that liquid-tightly seals the tip of the cylindrical body, the connection portion has a connecting needle that can penetrate the sealing member of the syringe, and a needle support member that supports the connecting needle, and the flexible tube connects the connecting needle and the puncture needle.

5. A drug solution administration device according to claim 4, comprising: a trigger member that moves relative to the casing in a proximal direction when pressed against the living body to be punctured; a plunger that is provided inside the casing and is movable relative to the syringe in a distal direction as the trigger member moves relative to the casing in the proximal direction, and that ejects the drug solution from the puncture needle when it moves in the distal direction; and a holding member that is provided inside the casing and holds the puncture unit, wherein, in an initial position of the trigger member, the connecting part is not connected to the distal end of the syringe, and the trigger member covers the distal end of the puncture unit, and when the trigger member performs a first operation of moving relative to the casing from the initial position in the proximal direction from the initial position toward a first position provided in the proximal direction, the connecting needle penetrates the sealing member and communicates with the interior of the cylindrical body, a second action of the trigger member moving relative to the housing from the first position in the proximal direction toward a second position that is further proximal from the first position, or a third action of the trigger member moving relative to the housing from the second position in the distal direction toward a third position that is further distal from the second position, the plunger moves relative to the syringe in the distal direction; and the trigger member has an engagement structure that engages the needle hub and the holding member with each other to prevent relative axial movement between the needle hub and the holding member at the initial position and the first position, the engagement structure including an elastic portion that is provided on the holding member and is elastically deformable radially outward, and at the initial position and the first position of the trigger member, an inner trigger wall of the trigger member faces the elastic portion, thereby preventing release of engagement by the engagement structure; and at the second position of the trigger member, the elastic portion and the inner trigger wall do not face each other, and the elastic portion deforms radially outward, thereby releasing engagement by the engagement structure.

Citation Information

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