Drug solution administration device

Abstract

A drug solution administration device (10A) is provided with a plunger holding structure (802) whereby a plunger (22) biased toward a tip direction by the resilient force of a resilient member (223) is held at a pre-activation position. The state in which the plunger (22) is held by the plunger holding structure (802) is released by performing a second operation in which the trigger member (14) moves relative to a housing (12) in the tip direction from the first position. The plunger (22) moves relative to a syringe (16) in the tip direction.

Description

Drug solution administration device

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

[0002] Japanese Patent Publication No. 2024-501422 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 a drug solution. When a user administers the drug solution, the puncture needle protrudes from the tip of the casing by pressing the tip of the casing against the skin to puncture the skin. After the puncture needle punctures the skin, the drug solution in the syringe is administered subcutaneously through the puncture needle.

[0003] Japanese Patent Publication No. 2024-501422

[0004] In the drug solution administration device as described above, it is desired to be able to administer the drug solution through the puncture needle with a simple configuration.

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

[0006] (1) An aspect of the present disclosure is a drug delivery device comprising: a housing; a syringe having a cylindrical body housed within the housing and filled with a drug solution; a puncture needle communicating with the inside of the cylindrical body for administering the drug solution into a living body; a trigger member that moves relative to the housing in the proximal direction when pressed against the target of puncture in the living body; and a plunger provided inside the housing, which is capable of moving relative to the syringe in the tip direction as the trigger member moves relative to the proximal direction, and which discharges the drug solution from the puncture needle when it moves in the tip direction, wherein the plunger is biased toward the tip direction by the elastic force of an elastic member provided inside the housing The drug dispensing device is equipped with a plunger holding structure that holds the plunger in a pre-activation position, and the trigger member is capable of performing a first operation in which it moves relative to the housing from the initial position toward the base end toward a first position provided in the direction toward the base end from the initial position, and a second operation in which it moves relative to the housing from the first position toward the tip toward a second position provided in the direction toward the tip toward the first position, and when the trigger member performs the second operation after performing the first operation, the plunger is released from the state in which the plunger is held by the plunger holding structure, and the plunger moves relative to the syringe toward the tip toward the syringe.

[0007] This drug administration device has a simple configuration, and the plunger is moved toward the syringe in response to the operation of the trigger member, allowing for effective drug administration.

[0008] (2) The drug dispensing device described in (1) above, comprising: a locking member movably provided inside the housing; and a holding part provided in the housing for holding the plunger in the initial position, wherein the plunger holding structure has a first engagement structure capable of engaging the locking member and the trigger member with each other; and a second engagement structure capable of engaging the holding part and the plunger with each other, wherein the engagement state of the first engagement structure may be released by the first operation of the trigger member, and the engagement state of the second engagement structure may be released by the second operation of the trigger member.

[0009] With this configuration, a first action of the trigger member allows the locking member to be moved relative to the trigger member, and a second action of the trigger member allows the plunger to be moved relative to the tip.

[0010] (3) In the drug dispensing device described in (2) above, the locking member has a locking projection that protrudes outward, the triggering member has a tip contact portion that abuts against the tip of the locking projection in the axial direction of the plunger, the tip contact portion has a notch in which a part of the circumferential direction of the triggering member is cut out in the radial direction, and by the first operation of the triggering member, the locking member is pressed against the tip contact portion and moves toward the base end, and the locking member rotates about the axis of the locking member, so that the locking projection and the notch face each other in the axial direction, and the engagement state of the first engagement structure is released.

[0011] This configuration allows the engagement state of the first engagement structure to be effectively released by the first action of the trigger member without moving the locking member in the axial direction.

[0012] (4) In the drug solution dispensing device described in (3) above, the plunger has a plunger projection that protrudes outward, the holding portion is provided radially outward of the plunger and has an elastic portion that protrudes radially inward toward the plunger, and in the initial position, the plunger projection and the base end of the elastic portion are in contact with the plunger in the axial direction, and the engagement state of the second engagement structure may be released by the deformation of the elastic portion radially outward.

[0013] This configuration allows for effective switching of the plunger's engagement state by providing a radially deformable elastic part in the housing's holding section.

[0014] (5) In the drug administration device described in (4) above, the trigger member has an engagement structure holding portion facing radially outward of the elastic portion in the initial position, the engagement structure holding portion maintains the engaged state of the second engagement structure from the initial position to the first position, and the engagement structure holding portion and the elastic portion move relative to each other in the axial direction by the second operation of the trigger member, thereby allowing deformation of the elastic portion radially outward.

[0015] This configuration effectively maintains the engagement state of the plunger by the second engagement structure from the initial position of the trigger member to the first position, while allowing the plunger to move toward the tip when the trigger member performs the second operation.

[0016] (6) In the drug solution dispensing device described in (5) above, the engagement structure holding portion may move to a release position that is further forward than the initial position by the second operation, and the elastic portion may be exposed radially outward from the base end of the engagement structure holding portion, thereby allowing the elastic portion to be deformed radially outward.

[0017] With this configuration, the second action of the trigger member causes the engagement structure holding portion to disappear from the radially outward side of the elastic portion, thereby making the elastic portion deformable radially outward.

[0018] (7) In the drug administration device described in any one of (2) to (6) above, the locking member has an insertion portion that is inserted into the plunger, and the insertion portion and the plunger have a contact structure in which they come into contact with each other in the axial direction, and the contact structure may have a contact portion provided on the plunger that comes into contact with the tip of the locking member and prevents the locking member from moving in the direction of the tip.

[0019] With this configuration, when the locking member and plunger are assembled, the contact structure allows for the axial positioning of the locking member and plunger.

[0020] (8) In the drug dispensing device described in any one of (4) to (7) above, the locking member may hold the engagement structure holding portion in the direction of the proximal end rather than the tip position at the initial position of the trigger member.

[0021] This configuration allows the engagement structure holding portion in its initial position to be effectively held in place by the locking member.

[0022] (9) In the drug dispensing device described in (8) above, the trigger member may have a base end contact portion that contacts the base end of the lock projection in the axial direction.

[0023] This configuration effectively prevents the trigger member from being displaced relative to the locking member in the tip direction at the base end contact point in the initial position.

[0024] (10) In the drug administration device described in any one of (1) to (9) above, the trigger member has a needle cover having an opening at its tip from which the puncture needle can be exposed, and a puncture unit having the puncture needle and a connecting portion that can communicate with the inside of the cylindrical body by being connected to the tip of the syringe, the puncture needle comprises a hollow cylindrical outer needle and an inner needle that can be inserted into the outer needle, the puncture unit has a needle hub that holds the inner needle, and by the first operation of the trigger member the puncture needle can be exposed to the outside from the opening of the needle cover, and by the second operation of the trigger member the needle hub can be detached from the puncture unit and the inner needle can be removed from the outer needle.

[0025] In this configuration, after the inner needle is withdrawn from the outer needle by the second action of the trigger member, the plunger moves relative to the syringe towards the tip, and the administration of the drug solution begins.

[0026] According to this disclosure, with a simple configuration, the plunger can be moved toward the syringe in conjunction with the operation of the trigger member, thereby effectively administering the drug solution.

[0027] Figure 1 is an external perspective view of a drug dispensing device according to the first embodiment of this disclosure. Figure 2 is an overall cross-sectional view of the drug dispensing device shown in Figure 1. Figure 3 is a cross-sectional view of the tip of the drug dispensing device shown in Figure 2. Figure 4 is a cross-sectional view of the base end of the drug dispensing device shown in Figure 2. Figure 5 is a cross-sectional view along the line V-V in Figure 3. Figure 6 is an enlarged perspective view showing the base end of the end cap and the locking member. Figure 7 is an enlarged perspective view showing the locking member and the sliding member. Figure 8 is an external perspective view of the puncture unit. Figure 9 is an external perspective view of the holding member and the puncture unit. Figure 10 is a cross-sectional view showing another cross-section of the base end of the drug dispensing device. Figure 11 is a cross-sectional view along the line XI-XI in Figure 4. Figure 12 is a cross-sectional view showing the second engagement structure of the drug dispensing device. Figure 13 is a cross-sectional explanatory view showing the initial position of the drug dispensing device. Figure 14 is a first explanatory view showing the operation of the drug dispensing device. Figure 15 is a second explanatory view showing the operation of the drug dispensing device. Figure 16 is a third explanatory view showing the operation of the drug dispensing device. Figure 17 is a fourth explanatory diagram showing the operation of the drug dispensing device. Figure 18 is a fifth explanatory diagram showing the operation of the drug dispensing device. Figure 19 is a perspective explanatory diagram showing the base end of the end cap and the locking member when the trigger member is in the first position. Figure 20 is a cross-sectional view when the trigger member is in the first position. Figure 21 is a sixth explanatory diagram showing the operation of the drug dispensing device. Figure 22 is a seventh explanatory diagram showing the operation of the drug dispensing device. Figure 23 is an eighth explanatory diagram showing the operation of the drug dispensing device. Figure 24 is a ninth explanatory diagram showing the operation of the drug dispensing device. Figure 25 is an explanatory diagram when the puncture unit is placed. Figure 26A is a first explanatory diagram showing drug dispensing by the drug dispensing device. Figure 26B is a second explanatory diagram showing drug dispensing by the drug dispensing device of Figure 26A. Figure 27 is a cross-sectional view of the drug dispensing device according to the second embodiment of the present disclosure. Figure 28 is a cross-sectional view of the tip of the drug dispensing device shown in Figure 27. Figure 29 is a cross-sectional view of the proximal end of the drug delivery device shown in Figure 27. Figure 30 is an external perspective view of the plunger. Figure 31 is an explanatory diagram showing the operation of the drug delivery device. Figure 32 is an explanatory diagram showing the placement of the puncture unit.

[0028] As shown in Figure 1, the drug administration device 10A according to the first embodiment is used, for example, to administer a drug solution R (see Figure 2) subcutaneously to a patient C (a living organism, see Figure 14), who is a user.

[0029] As shown in Figure 2, the drug 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 housing 12, a puncture unit 18 capable of puncturing the skin S (see Figure 14) of patient C (see Figure 14), a holding member 20 that holds the puncture unit 18, and a plunger 22 provided inside the housing 12.

[0030] The housing 12 is formed from a resin material in a hollow cylindrical shape. The housing 12 has a main body 121 that extends along the axial direction (arrows A and B), a sleeve body 122 housed at the base end side (arrow A direction) of the main body 121, and an end cap 123 that closes the base end of the main body 121. The sleeve body 122 is formed in a hollow shape.

[0031] The main body 121 is a long, cylindrical shape in the axial direction (arrows A and B). The tip and base of the main body 121 are open. The peripheral wall of the main body 121 is provided with a window 124. Through the window 124, the user can check the drug solution R inside the syringe 16 from outside the housing 12.

[0032] As shown in Figure 2, in the drug dispensing device 10A before use, a tip cap 24 is attached to the housing 12. As shown in Figure 3, the tip cap 24 is formed in a bottomed cylindrical shape and engages with the tip 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 drug dispensing device 10A before use, the tip cap 24 covers the trigger member 14 and the tip of the housing 12. When using the drug dispensing device 10A, the tip cap 24 can be removed from the tip of the housing 12 (see Figure 13). By removing the tip cap 24 from the housing 12, the protective cover 26 is removed along with the tip cap 24, and the tip of the puncture needle 181 is exposed (see Figure 13).

[0033] As shown in Figure 4, the end cap 123 is provided at the base end of the housing 12. The end cap 123 has a cover portion 1231 and a shaft portion 1232 extending from the cover portion 1231 toward the tip (direction of arrow B). The cover portion 1231 is formed in a disc shape. The base end of the main body 121 is closed when the cover portion 1231 is fixed to the base end of the sleeve body 122.

[0034] The end cap 123 further includes contact portions 1233. As shown in Figure 6, the contact portions 1233 are provided on the inner surface of the lid portion 1231. The contact portions 1233 protrude from the inner surface of the lid portion 1231 toward the tip. A pair of contact portions 1233 are provided spaced apart from each other in the circumferential direction of the end cap 123. Each contact portion 1233 is spaced radially outward with respect to the shaft portion 1232. In the axial direction of the end cap 123, the contact portions 1233 and the locking member 801 face each other (see Figure 4).

[0035] As shown in Figure 2, the trigger member 14 is pressed against the skin S (the target of puncture) of the patient C, causing it to be displaced relative to the housing 12 in the proximal direction (direction of arrow A) (see Figure 16). The trigger member 14 is movably positioned inside the main body 121 of the housing 12. The trigger member 14 is movably positioned between an initial position, a first position located proximal to the initial position, and a second position located distal to the first position.

[0036] The trigger member 14 comprises a needle cover 14a and a slide member 14b.

[0037] The needle cover 14a is provided to accommodate the puncture unit 18. The needle cover 14a comprises a cylindrical trigger body 141 and a pair of cover portions 142 extending from the trigger body 141 in the direction of the proximal end (direction of arrow A). The needle cover 14a has an extension portion (not shown) extending from the cover portion 142 in the direction of the proximal end connected to a slide member 14b. As shown in Figure 3, in the initial state before use of the drug administration device 10A, the tip of the trigger member 14 protrudes further in the direction of the tip (direction of arrow B) than the tip of the housing 12. In the initial position of the trigger member 14, the trigger member 14 covers the tip of the puncture unit 18.

[0038] The trigger body 141 is formed at the tip of the trigger member 14. The trigger body 141 has an opening 144. The opening 144 is formed in the center of the tip of the trigger body 141 and penetrates the trigger member 14 in the axial direction. When the trigger member 14 moves relative to the housing 12 in the direction of the base end, the puncture needle 181 of the puncture unit 18 can be inserted through the opening 144 (see Figure 17).

[0039] As shown in Figure 4, the slide member 14b is formed in a cylindrical shape (see also Figure 7). The slide member 14b is provided to be movable in the axial direction inside the main body 121 of the housing 12. The slide member 14b is positioned towards the base end of the needle cover 14a and is connected to the base end of the needle cover 14a. The slide member 14b is provided radially outward of the sleeve body 122. The slide member 14b and the needle cover 14a are integrally movable in the axial direction.

[0040] As shown in Figure 7, the slide member 14b has a cylindrical sleeve body 151 and a pair of base end arms 152 extending from the base end of the sleeve body 151.

[0041] As shown in Figure 4, a sleeve spring 153 is provided between the sleeve body 151 and the base end of the sleeve body 122. The sleeve spring 153 is provided between the outer circumferential surface of the sleeve body 122 and the inner circumferential surface of the housing 12. The sleeve spring 153 is an elastic member made of a coil spring. The base end of the sleeve spring 153 is engaged with the sleeve body 122. The tip of the sleeve spring 153 is engaged with the sleeve body 151 of the slide member 14b. The elastic force of the sleeve spring 153 biases the slide member 14b in a direction that separates it from the sleeve body 122, that is, toward the tip (direction of arrow B). The elastic force of the sleeve spring 153 makes the trigger member 14 movable toward the tip.

[0042] As shown in Figure 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 are provided between the pair of cover portions 142. Each slit 32 extends from the trigger body 141 toward the base end.

[0043] The pair of cover parts 142 has 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 parts 142. The plurality of trigger inner walls 34 are spaced apart from each other along the circumferential direction of the cover part 142. Each of the plurality of trigger inner walls 34 is arranged at a distance from the tip end of the trigger body 141 toward the base end. Each of the plurality of trigger inner walls 34 extends along the axial direction of the trigger body 141 (see FIG. 3).

[0044] As shown in FIG. 2, the syringe 16 is fixed inside the housing 12. The syringe 16 is fixed inside the housing 12 via a syringe holder 17. The syringe 16 includes a cylinder body 161, a sealing member 162, and a stopper 163. The cylinder body 161 is formed of a transparent resin material. The cylinder body 161 is a hollow body with an open base end. Inside the cylinder body 161, there is a medicine chamber 164 filled with a medicine solution R. Note that, as the medicine solution R, there is, for example, one used for subcutaneous injection of a user (patient C). The outer peripheral portion of the base end of the cylinder body 161 has a flange 165 protruding radially outward.

[0045] As shown in FIG. 3, the tip end of the cylinder body 161 has a tip end holding portion 166. The tip end holding portion 166 has a reduced diameter compared to the cylinder body 161 and protrudes toward the tip end. The tip end holding portion 166 has a hole portion 38 communicating with the medicine chamber 164. The hole portion 38 penetrates in the axial direction of the syringe 16. A syringe cap 167 is attached to the tip end holding portion 166. The tip end holding portion 166 of the cylinder body 161 of the syringe 16 is covered by the syringe cap 167. The cylinder body 161 of the syringe 16 is held by the syringe holder 17.

[0046] The sealing member 162 is formed of an elastic material such as rubber. The sealing member 162 is held at the central portion of the syringe cap 167. The tip end of the hole portion 38 in the cylinder body 161 is covered by the sealing member 162. The sealing member 162 seals the tip end portion of the cylinder body 161 in a liquid-tight manner. The medicine solution R in the medicine chamber 164 in the cylinder body 161 is sealed by the sealing member 162.

[0047] As shown in Fig. 2, the stopper 163 is provided in the medicine chamber 164 of the cylinder body 161. The stopper 163 is provided so as to be movable in the tip direction (arrow B direction) along the axial direction of the cylinder body 161. The stopper 163 is slidably inserted into the medicine chamber 164 of the cylinder body 161. The stopper 163 is formed of an elastic material such as rubber. The stopper 163 is attached to the tip of the plunger 22. The stopper 163 protrudes in the tip direction with respect to the tip of the plunger 22. The stopper 163 is inserted into the medicine chamber 164 of the cylinder body 161 from the base end of the cylinder body 161. By inserting the stopper 163 into the inside of the cylinder body 161, the base end side of the cylinder body 161 is liquid-tightly sealed and the chemical solution R in the medicine chamber 164 is enclosed inside the cylinder body 161.

[0048] As shown in Fig. 3, the puncture unit 18 includes a puncture needle 181, a unit body 182, a needle hub 183, and a flexible tube 184.

[0049] The puncture needle 181 is provided so as to be able to administer the chemical solution R subcutaneously to the patient C (see Fig. 25). The puncture needle 181 includes a hollow cylindrical outer needle 401 and an inner needle 402 that can be inserted inside the outer needle 401. That is, the puncture needle 181 is a double needle. The outer needle 401 is a hollow body having a flow path inside which the chemical solution R flows. The flow path of the outer needle 401 communicates with the medicine chamber 164 of the cylinder body 161 filled with the chemical solution R. In the initial state of the puncture needle 181, the tip of the inner needle 402 protrudes in the tip direction from the tip of the outer needle 401 (see Fig. 3).

[0050] The unit body 182 includes a connection part 42 and an intermediate member 44 arranged in the tip direction (arrow B direction) of the connection part 42. The connection part 42 is formed so as to be able to communicate with the inside of the cylinder body 161 by connecting to the tip of the syringe 16. The connection part 42 includes a connection needle 421 and a needle support member 422 that supports the connection needle 421.

[0051] The connecting needle 421 communicates with the puncture needle 181 and is formed 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 located in the center of the needle support member 422 and protrudes from the partition wall portion 46 of the needle support member 422 toward the base end (direction of arrow A). In the axial direction of the trigger member 14, the connecting needle 421 and the sealing member 162 of the syringe 16 face each other. In the initial position of the trigger member 14, the connecting needle 421 of the connecting portion 42 is not connected to the tip of the syringe 16.

[0052] When the trigger member 14 moves relative to the housing 12 toward a first position located toward the base end from its initial position (hereinafter referred to as the "first operation"), the connecting needle 421 penetrates the sealing member 162 and communicates with the chamber 164 of the cylindrical body 161 (see Figure 15).

[0053] As shown in Figure 3, the needle support member 422 has a first recess 481 and a first tube connecting portion 501. The first recess 481 is located toward the tip of the partition wall portion 46 and opens toward the tip. The tip 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.

[0054] The intermediate member 44 is provided between the connecting portion 42 and the needle hub 183. The intermediate member 44 is fixed to the tip of the needle support member 422. The intermediate member 44 holds the base end of the inner needle 402 in the puncture needle 181. In other words, the intermediate member 44 is the inner needle hub 44a. The inner needle hub 44a is positioned in the direction of the base end of the needle hub 183 (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 inside. An annular first magnet M1 is housed at the tip of the second recess 482.

[0055] As shown in Figure 8, the outer circumferential surface of the inner needle hub 44a has a first accommodating groove 541 that is recessed radially inward. The first accommodating groove 541 is formed in a single spiral shape centered on the axis of the inner needle hub 44a.

[0056] The needle hub 183 is provided in the tip direction of the unit body 182. The needle hub 183 is provided so as to be detachable from the unit body 182 (see Figure 22). As shown in Figure 3, the needle hub 183 holds the proximal end of the outer needle 401 of the puncture needle 181. That is, 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. An adhesive material 56 is provided at the tip of the needle hub 183. The adhesive material 56 is formed in a sheet shape and is attached along the tip of the needle hub 183. The adhesive surface of the adhesive material 56 is the surface opposite to the surface attached to the needle hub 183.

[0057] With the puncture needle 181 puncturing the patient C's skin S, the tip of the needle hub 183 is placed in the skin S. At this time, the adhesive surface of the adhesive material 56 contacts and is fixed to the surface of the patient C's skin S (see Figure 17). Note that the needle hub 183 is not limited to having the adhesive material 56 at its tip. For example, the tip of the needle hub 183 may be provided with a fixing structure (adhesive part) that can be fixed to the skin S.

[0058] The needle hub 183 has a communication chamber 52 and a second tube connecting portion 502. The communication chamber 52 is located 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.

[0059] 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 in place by the needle hub 183. In the axial direction of the puncture unit 18, the first magnet M1 and the second magnet M2 are arranged coaxially. The magnetic forces of the first magnet M1 and the second magnet M2 connect the needle hub 183 and the inner needle hub 44a to each other in the axial direction. The cap 57 is formed in the shape of a plate from an elastic material such as rubber. The base end of the communication chamber 52 is covered by the cap 57. The communication chamber 52 is liquid-tightly sealed by the cap 57.

[0060] A hub cover 58 is provided at the base end of the needle hub 183. The hub cover 58 covers the base end of the needle hub 183. The needle hub 183, hub cover 58, and inner needle hub 44a are arranged in a line toward the base end in the axial direction of the puncture unit 18. The tip of the inner needle hub 44a faces the hub cover 58. The hub cover 58 has a through hole 581 that penetrates axially through 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 circumferential surface of the hub cover 58 has a second housing groove 542 that is recessed radially inward. The second housing groove 542 is formed in a single spiral shape centered on the axis of the hub cover 58 (see Figure 8). The first housing groove 541 of the inner needle hub 44a and the second housing groove 542 of the hub cover 58 form a continuous spiral housing groove 54.

[0061] The flexible tube 184 connects the unit body 182 and the needle hub 183. The flexible tube 184 connects the connecting needle 421 of the connection portion 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 spiral manner. However, the flexible tube 184 is not limited to being shaped in a spiral. For example, the flexible tube 184 may be formed in a non-spiral shape.

[0062] 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 connecting needle 421 of the puncture unit 18 and the communication chamber 52 of the needle hub 183 communicate with each other via the flexible tube 184.

[0063] The flexible tube 184 is wound around the outer circumference of the unit body 182 and housed inside the housing 12 in a flexible state. The flexible tube 184 has an intermediate section 603. The intermediate section 603 is provided between the tip 601 and the base end 602 of the flexible tube 184. As shown in Figure 8, the intermediate section 603 of the flexible tube 184 is wound around and housed in a continuous housing groove 54 formed by the first housing groove 541 of the inner needle hub 44a and the second housing groove 542 of the hub cover 58.

[0064] When the needle hub 183 is separated from the unit body 182, at least a portion of the flexible tube 184 is exposed to the outside from the tip of the housing 12. A portion of the flexible tube 184 protrudes from the housing 12 toward the tip (direction of arrow B), and the middle portion 603 of the flexible tube 184 extends (see Figure 22).

[0065] As shown in Figure 3, the holding member 20 is provided inside the housing 12 and holds the puncture unit 18. As shown in Figure 9, the holding member 20 comprises a holder body 201 and a pair of first arm portions 202. The holder body 201 is formed in a cylindrical shape. As shown in Figure 3, the holder body 201 houses the inner needle hub 44a, the hub cover 58, and the needle hub 183. The base end of the holder 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 holding member 20 and the needle support member 422 are engaged and connected by the pair of hooks 203.

[0066] As shown in Figure 4, the plunger 22 is a cylindrical shape that is elongated in the axial direction. The plunger 22 is housed inside the housing 12 so as to be movable in the axial direction.

[0067] The plunger 22 comprises a cylindrical rod body 221 and a mounting portion 222 formed at the tip of the rod body 221. The stopper 163 of the syringe 16 is attached to the mounting portion 222. An elastic member 223 is provided inside the rod body 221.

[0068] The resilient member 223 is provided between the tip of the rod body 221 and the end cap 123. The resilient force of the resilient member 223 biases the plunger 22 toward the tip (direction of arrow B). In the drug administration device 10A before use, the plunger 22 is held in the pre-activation position by the activation prevention mechanism 80, which will be described later. As the trigger member 14 moves toward the tip (second operation), the resilient force of the resilient member 223 allows the plunger 22 to move toward the tip relative to the syringe 16. By moving toward the tip relative to the syringe 16, the plunger 22 causes the drug solution R in the chamber 164 to be discharged from the puncture needle 181 (see Figure 25).

[0069] As shown in Figure 1, a sealing cap 66 is further attached to the housing 12 of the drug dispensing device 10A before use. The sealing cap 66 is detachably provided at the tip of the main body 121 of the housing 12. As shown in Figure 3, the sealing cap 66 comprises a cap body 661, a first sealing member 681, and a second sealing member 682.

[0070] The cap body 661 is attached to the outer circumferential surface of the main body 121. The cap body 661 is formed in an arc shape that extends along the circumferential direction of the main body 121 (see Figure 1). The cap body 661 is inserted into a side wall opening 72 that opens in the circumferential wall of the main body 121. The gripping portion 70 is plate-shaped and protrudes radially outward from the outer circumferential surface of the cap body 661. When removing the sealing cap 66 from the housing 12, the user can grip the gripping portion 70.

[0071] 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. Each of the first sealing member 681 and the second sealing member 682 is provided projecting 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 substantially parallel.

[0072] Before use, the tip of the first sealing member 681 is in contact with and attached to the end face of the sealing member 162 of the syringe 16. The end face of the sealing member 162 is covered by the first sealing member 681, maintaining the sterile state of the sealing member 162. Before use, the tip of the second sealing member 682 is in contact with and attached 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, maintaining the sterile state of the connecting needle 421.

[0073] When using the drug administration device 10A, removing the sealing cap 66 from the housing 12 causes the first sealing member 681 to detach from the sealing member 162 and the second sealing member 682 to detach from the needle support member 422. The first sealing member 681 and the second sealing member 682 are then removed from the housing 12 through the side wall opening 72.

[0074] As shown in Figure 3, the drug administration device 10A further comprises a first connection structure 741, a second connection structure 742, and a third connection structure 743.

[0075] The first connection structure 741 engages the housing 12 and the retaining member 20 with each other at an engagement position located towards the tip of the trigger member 14 from its first position (see Figure 15). The first connection structure 741 prevents relative axial movement between the housing 12 and the retaining member 20 at the engagement position of the trigger member 14. The first connection structure 741 comprises a pair of first connecting portions 76 provided on the retaining member 20 and a pair of second connecting portions 78 provided on the housing 12 that engage with the pair of first connecting portions 76.

[0076] The pair of first connecting portions 76 extend from the base ends of the pair of first arm portions 202 in the direction toward the base ends. Each first connecting portion 76 has a first connecting hole 761 that penetrates radially.

[0077] A pair of second connecting portions 78 are provided at the tip of the syringe holder 17. Each second connecting portion 78 is positioned inside the first connecting portion 76 of the holding member 20. The pair of second connecting portions 78 protrude radially outward from the tip of the syringe holder 17. At the engagement position of the trigger member 14, each second connecting portion 78 engages with the first connecting hole 761 of each first connecting portion 76. The engagement of the first connecting portion 76 and the second connecting portion 78 prevents relative axial movement between the housing 12 and the holding member 20.

[0078] The second connection structure 742 engages the trigger member 14 and the retaining member 20 with each other in the initial position of the trigger member 14. The second connection structure 742 prevents axial relative movement between the trigger member 14 and the retaining member 20 in the initial position of the trigger member 14. The second connection structure 742 includes a first elastic portion 81 provided on the retaining member 20 that is elastically deformable radially outward.

[0079] A pair of first elastic portions 81 are provided on the holding member 20 radially outward from the holder body 201. The base ends of the pair of first elastic portions 81 are supported by the base ends of the holder body 201. Each of the pair of first elastic portions 81 and the holder body 201 are spaced apart from each other radially. The pair of first elastic portions 81 are spaced apart from each other in the circumferential direction of the holding member 20. The pair of first elastic portions 81 are provided so that their tips can tilt with their base ends as a fulcrum. The base end of each first elastic portion 81 is a first fixed end 811 fixed to the holder body 201. The tip of each first elastic portion 81 is a first free end 812.

[0080] Each first elastic portion 81 has a first contact portion 83 at its tip. The first contact portion 83 protrudes radially inward from the tip of each first elastic portion 81. The tip of the first contact portion 83 has an inclined portion 831 that is inclined radially inward toward the base end. In the initial position of the trigger member 14, the first elastic portion 81 faces the inner wall 125 of the housing 12 (main body 121). The inner wall 125 is provided at the tip of the main body 121. The inner wall 125 is positioned radially outward of the first elastic portion 81. The inner wall 125 restricts the radially outward movement of the first elastic portion 81.

[0081] The second connection structure 742 further includes a second contact portion 85. As shown in Figure 5, the second contact portion 85 is provided on a pair of cover portions 142 of the trigger member 14. The second contact portion 85 is provided on a wall portion 87 that protrudes from the cover portion 142 toward the slit 32. The second contact portion 85 is provided at the base end of the wall portion 87 (see Figure 3). The second contact portion 85 protrudes from the wall portion 87 in the circumferential direction of the trigger member 14. The second contact portion 85 is provided toward the tip of the first contact portion 83 of the retaining member 20. When the trigger member 14 moves toward the base end, the second contact portion 85 is provided so as to be able to come into contact with the first contact portion 83. The contact between the first contact portion 83 and the second contact portion 85 maintains the axial engagement between the trigger member 14 and the retaining member 20. The second connection structure 742 prevents relative movement between the trigger member 14 and the holding member 20, allowing them to move together as a single unit.

[0082] As shown in Figure 3, the third connection structure 743 engages the needle hub 183 and the retaining member 20 with each other in the initial position of the trigger member 14. The third connection structure 743 prevents relative axial movement between the needle hub 183 and the retaining member 20 in the initial position of the trigger member 14. As shown in Figure 5, the third connection structure 743 includes a plurality of protrusions 89 provided on the needle hub 183 and a second elastic portion 91 provided on the retaining member 20 that is elastically deformable radially outward.

[0083] Each of the multiple protrusions 89 is provided on the outer circumferential surface of the needle hub 183. The multiple protrusions 89 project radially outward from the outer circumferential surface of the needle hub 183. The multiple protrusions 89 are spaced apart from each other in the circumferential direction of the needle hub 183. The case with three protrusions 89 will be described below.

[0084] As shown in Figure 9, the second elastic portion 91 is provided at the tip of the holder body 201 of the holding member 20. As shown in Figure 5, the second elastic portion 91 has a plurality of second arm portions 911. Each of the plurality of second arm portions 911 is provided so as to be elastically deformable radially outward relative to the holder body 201. The plurality of second arm portions 911 are spaced apart from each other in the circumferential direction of the holder body 201. The number of second arm portions 911 is the same as the number of projections 89. The case with three second arm portions 911 will be described below. As shown in Figure 9, each second arm portion 911 extends in the circumferential direction of the holder body 201. The second arm portion 911 has a second fixed end 931 and a second free end 932. The second fixed end 931 is one end of the second arm portion 911 in the circumferential direction of the holder body 201. The second fixed end 931 is fixed to the holder body 201. When the second arm portion 911 undergoes elastic deformation in the radial direction, the second fixed end 931 is the starting point. The second free end 932 is the other end of the second arm portion 911 in the circumferential direction of the holder body 201. The second free end 932 deforms radially outward relative to the holder body 201 (see Figure 21).

[0085] The second arm portion 911 has a second connecting hole 95 into which the projection 89 of the needle hub 183 can engage. The second connecting hole 95 is formed in the second free end 932. The second connecting hole 95 penetrates the holder body 201 radially in the second arm portion 911. When the projection 89 engages with the second connecting hole 95, relative axial movement between the holding member 20 and the needle hub 183 is prevented.

[0086] In the initial position of the trigger member 14, each second elastic portion 91 faces each trigger inner wall 34 of the trigger member 14 in the radial direction of the trigger member 14 (see Figure 5). Each trigger inner wall 34 is positioned radially outward of each second elastic portion 91. Each trigger inner wall 34 prevents each second elastic portion 91 from moving radially outward, and the engagement between the projection 89 and the second connection hole 95 is maintained. The engagement between the needle hub 183 and the retaining member 20 by the third connection structure 743 is maintained.

[0087] As shown in Figure 10, the drug dispensing device 10A further includes an activation prevention mechanism 80 and a contact structure 82.

[0088] The activation prevention mechanism 80 holds the plunger 22 in the pre-activation position. The pre-activation position of the plunger 22 is the position where the plunger 22 is positioned towards the proximal end relative to the syringe 16, and the stopper 163 is in its most proximal position and not pushing the drug solution R toward the tip (see Figure 2).

[0089] As shown in Figure 4, the activation prevention mechanism 80 comprises a locking member 801 and a plunger holding structure 802. The locking member 801 is provided inside the housing 12. The locking member 801 is formed in a cylindrical shape and is movably provided inside the sleeve body 122. Inside the housing 12, the locking member 801 is provided so as to be axially movable and rotatable about the axis of the housing 12.

[0090] As shown in Figure 6, the locking member 801 comprises an insertion portion 84 and a protruding wall portion 86. The insertion portion 84 is formed in a cylindrical shape and extends in the axial direction. The insertion portion 84 is inserted into the inside of the plunger 22 (see Figure 4).

[0091] As shown in Figure 7, the protruding wall portion 86 protrudes from the base end of the locking member 801 toward the base end. A pair of protruding wall portions 86 are provided spaced apart from each other in the circumferential direction of the locking member 801. The base end of each protruding wall portion 86 has an inclined surface 861 that extends in a direction that gradually moves away from the base end along the circumferential direction of the locking member 801. The inclination direction of the base ends of each protruding wall portion 86 is the same. The base end of each protruding wall portion 86 is inclined so as to gradually move toward the tip in the direction of arrow F (see also Figure 12). When the locking member 801 moves toward the base end, each protruding wall portion 86 contacts the contact portion 1233 of the end cap 123 (see Figures 18 and 19).

[0092] As shown in Figure 4, the plunger holding structure 802 holds the plunger 22, which is biased toward the tip by the elastic force of the elastic member 223, in the pre-activation position. The plunger holding structure 802 comprises a first engagement structure 881 and a second engagement structure 882.

[0093] As shown in Figure 10, the first engagement structure 881 is capable of engaging the locking member 801 and the trigger member 14 with each other. The first engagement structure 881 includes a locking projection 90 provided on the locking member 801 and an engagement portion 92 provided on the trigger member 14 (see Figure 7).

[0094] The locking projection 90 is provided at the base end of the locking member 801. The locking projection 90 protrudes radially outward from the outer circumference of the locking member 801. As shown in Figure 11, a pair of locking projections 90 are provided spaced apart from each other in the circumferential direction of the locking member 801. However, the locking projections 90 are not limited to being provided in a pair. An insertion portion 94 is provided between the pair of locking projections 90.

[0095] As shown in Figure 10, the engaging portion 92 is provided at the base end of the slide member 14b (base arm 152). The engaging portion 92 comprises a base contact portion 921 and a tip contact portion 922.

[0096] The base end contact portion 921 abuts against the base end of the lock projection 90 in the axial direction of the trigger member 14. The base end contact portion 921 protrudes radially inward from the base end of the slide member 14b. A pair of base end contact portions 921 are provided spaced apart from each other in the circumferential direction of the slide member 14b. The lock projection 90 abuts against the base end contact portion 921, thereby preventing the relative movement of the lock member 801 relative to the slide member 14b in the base end direction.

[0097] The tip contact portion 922 contacts the tip of the lock projection 90 in the axial direction of the plunger 22. The tip contact portion 922 is positioned further forward than the base contact portion 921 at the base end of the slide member 14b. In the axial direction of the slide member 14b, the tip contact portion 922 and the base contact portion 921 are spaced apart from each other. The lock projection 90 contacting the tip contact portion 922 prevents the lock member 801 from moving relative to the slide member 14b in the forward direction. As shown in Figure 11, the tip contact portion 922 has a notch 96. The notch 96 is formed by cutting out a portion of the trigger member 14 in the radial direction in the circumferential direction. A pair of notches 96 are provided spaced apart from each other in the circumferential direction of the slide member 14b (see also Figure 7).

[0098] As shown in Figure 10, in the initial position of the trigger member 14, the locking projection 90 is positioned between the tip contact portion 922 and the base contact portion 921.

[0099] As shown in Figure 12, the second engagement structure 882 is capable of engaging the sleeve body 122 and the plunger 22 with each other. The second engagement structure 882 comprises a retaining portion 98 provided on the sleeve body 122 and a plunger projection 100 provided on the plunger 22.

[0100] The retaining portion 98 holds the plunger 22 in the initial position of the trigger member 14. The retaining portion 98 is provided radially outward of the plunger 22. The retaining portion 98 has an elastic portion 102. The elastic portion 102 protrudes radially inward toward the plunger 22. The elastic portion 102 is provided so as to be deformable radially outward of the sleeve body 122. The tip of the elastic portion 102 has a claw portion 1021. The claw portion 1021 protrudes radially inward.

[0101] The plunger projection 100 protrudes radially outward from the outer circumferential surface of the rod body 221 of the plunger 22. The plunger projection 100 is provided at the base end of the rod body 221.

[0102] In the initial position of the trigger member 14, the plunger projection 100 is positioned further towards the base end than the claw portion 1021 of the elastic portion 102. The plunger projection 100 and the base end of the claw portion 1021 come into contact with each other in the axial direction. The plunger projection 100 and the claw portion 1021 of the elastic portion 102 are engaged with each other. In the initial position of the trigger member 14, the second engagement structure 882 prevents relative movement of the plunger 22 toward the tip relative to the housing 12.

[0103] The slide member 14b further includes an engagement structure holding portion 104. The engagement structure holding portion 104 maintains the engaged state of the second engagement structure 882 from the initial position to the first position of the trigger member 14. At the initial position of the trigger member 14, the engagement structure holding portion 104 faces radially outward of the elastic portion 102 of the sleeve body 122. At the initial position, the engagement structure holding portion 104 prevents radially outward movement of the elastic portion 102.

[0104] The contact structure 82 ensures that the insertion portion 84 of the locking member 801 and the plunger 22 are in axial contact with each other. The contact structure 82 includes a contact portion 821, which is provided on the rod body 221 of the plunger 22. The contact portion 821 contacts the tip of the insertion portion 84 of the locking member 801. The contact portion 821 prevents relative movement of the locking member 801 toward the tip of the plunger 22 by contacting the tip of the insertion portion 84.

[0105] Next, the drug administration device 10A is used as follows.

[0106] First, in the drug administration device 10A shown in Figure 2 before use, the tip cap 24 is removed from the housing 12 and the tip of the trigger member 14 (see Figure 13). As shown in Figure 13, by removing the tip cap 24, the tips of the housing 12 and the trigger member 14 are opened, and the protective cover 26 that was covering the puncture needle 181 is simultaneously removed. The sealing cap 66 is removed from the outer circumferential surface of the housing 12. By removing the sealing cap 66 radially outward relative to the housing 12, the first sealing member 681 and the second sealing member 682 are pulled radially outward by the sealing cap 66. As a result, the first sealing member 681 is separated from the sealing member 162, and the second sealing member 682 is separated from the needle support member 422. The separated first sealing member 681 and the second sealing member 682 are each removed to the outside of the housing 12 through the side wall opening 72 of the housing 12. The connecting needle 421 of the connection part 42 and the sealing member 162 of the syringe 16 face each other in the axial direction.

[0107] Next, the drug solution R is administered using the drug solution dispensing device 10A from which the tip cap 24 and sealing cap 66 have been removed.

[0108] In the pre-puncture state of the drug administration device 10A, the trigger member 14 (needle cover 14a) is in an initial position covering the tip of the puncture 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 81 of the retaining member 20 and the inner wall 125 of the housing 12 face each other in the radial direction. Therefore, in the initial position, radial outward deformation of the first elastic portion 81 is prevented, and the trigger member 14 and the retaining member 20 are engaged with each other. The trigger member 14 and the retaining member 20 are engaged with each other by the second connecting structure 742. As a result, the trigger member 14 and the retaining member 20 do not move relative to each other in the axial direction. Furthermore, as shown in Figure 12, the plunger holding structure 802 prevents radial outward deformation of the elastic portion 102, so that the elastic portion 102 and the plunger projection 100 remain engaged. In other words, the activation prevention mechanism 80 prevents the plunger 22 from moving toward the tip, and the plunger 22 is held in the pre-activation position.

[0109] Next, as shown in Figure 14, the user grasps the housing 12 and presses the tip of the trigger member 14 protruding from the front of the housing 12 against the skin S of patient C, which is the desired puncture site, at approximately a right angle. Next, the user continuously pushes the housing 12 further toward the skin S (towards the front, in the direction of arrow B). As the housing 12 is pushed toward the skin S, the trigger member 14 is pushed by the skin S and moves relative to it from its initial position toward the base end (in the direction of arrow A, first position). At this time, the trigger member 14 moves relative to the housing 12 toward the base end against the elastic force of the sleeve spring 153.

[0110] As the trigger member 14 performs a first operation toward the first position relative to the housing 12, the second contact portion 85 of the trigger member 14 and the first contact portion 83 of the holding member 20 come into contact. The second contact portion 85 of the trigger member 14 pushes the first contact portion 83 toward the base end, causing the puncture unit 18 to move toward the first position together with the trigger member 14. At this time, the syringe 16 does not move relative to the housing 12. As shown in Figure 15, as the puncture unit 18 moves toward the base end (direction of arrow A), the base end of the connecting needle 421 of the connecting portion 42 punctures the sealing member 162 of the syringe 16. The connecting needle 421 penetrates the sealing member 162. As a result, the connecting needle 421 and the chamber 164 of the syringe 16 are in communication. At the engagement position located toward the tip from the first position, the tip of the second connecting portion 78 is inserted into and engaged with the first connecting hole 761 of the first connecting portion 76. This prevents relative axial movement of the holding member 20 and the puncture unit 18 with respect to the housing 12 and syringe holder 17.

[0111] As shown in Figure 16, the user moves the housing 12 further toward the skin S, pushing the tip of the trigger member 14 further inward toward the base end. The trigger member 14 moves toward a first position which is located further toward the base end than the engagement position.

[0112] During the first operation of the trigger member 14, the radially outward portion of the elastic portion 102 of the plunger holding structure 802 is covered by the slide member 14b. As a result, the engagement between the elastic portion 102 and the plunger projection 100 is maintained, and the plunger 22 is kept in its pre-activation position. In other words, the plunger 22 is kept in a state where its movement toward the tip (activation) is prevented.

[0113] As the trigger member 14 performs its first movement, the second connection structure 742 releases its restriction on relative movement between the trigger member 14 and the holding member 20, allowing the trigger member 14 and the holding member 20 to move relative to each other in the axial direction. As the trigger member 14 moves toward the proximal end relative to the puncture unit 18, the tip of the trigger member 14 (needle cover 14a) comes into contact with the skin S, reaching a first position (see Figure 17). As shown in Figure 17, at the first position of the trigger member 14, the puncture needle 181 of the puncture unit 18 protrudes toward the tip from the opening 144 of the trigger member 14 (needle cover 14a). That is, the puncture needle 181 is exposed to the outside from the opening 144 of the needle cover 14a.

[0114] As a result, the tip of the puncture needle 181 penetrates the skin S and is inserted to a predetermined depth. The tip surface of the needle hub 183 comes into contact with the skin S, and the adhesive surface of the adhesive material 56 adheres to the surface of the skin S. As a result, with the puncture needle 181 having penetrated the skin S, the tip of the needle hub 183 is fixed to the surface of the skin S. The puncture is completed, with the skin S of patient C having been punctured by the puncture needle 181. In the first position of the trigger member 14, the restriction on relative movement between the needle hub 183 and the holding member 20 by the third connecting structure 743 is released, and the needle hub 183 and the holding member 20 become able to move relative to each other in the axial direction. At this time, the puncture needle 181 is inserted with the tip of the inner needle 402 protruding further in the tip direction than the tip of the outer needle 401.

[0115] As the trigger member 14 performs its first action, the slide member 14b and the locking member 801 move towards the base end inside the housing 12. Specifically, the locking member 801 is pressed against the tip contact portion 922 of the slide member 14b and moves toward the base end (see Figure 18).

[0116] Then, as shown in Figure 18, the protruding wall portion 86 of the locking member 801 comes into contact with the contact portion 1233 of the end cap 123. As the locking member 801 moves further toward the base end, the protruding wall portion 86 comes into contact with the inclined surface 861 of the protruding wall portion 86, and as shown in Figure 19, the protruding wall portion 86 rotates in the direction of arrow F (see Figure 20) about the axis of the locking member 801. The locking member 801 rotates relative to the sliding member 14b.

[0117] As the locking member 801 rotates in the direction of arrow F, the locking projection 90 moves circumferentially around the slide member 14b between the tip contact portion 922 and the base contact portion 921, as shown in Figure 20. When the trigger member 14 reaches the first position, the pair of locking projections 90 face the pair of notches 96 of the tip contact portion 922. The contact between the locking projection 90 and the tip contact portion 922 is released. This releases the axial relative movement restriction between the locking member 801 and the slide member 14b by the first engagement structure 881. The locking member 801 can now move relative to the slide member 14b in the tip direction. In other words, the engagement state of the first engagement structure 881 is released by the first operation of the trigger member 14.

[0118] As shown in Figure 21, the first movement of the trigger member 14 causes the trigger inner wall 34 to move relative to the second elastic portion 91 of the holding member 20 in the direction of the base end (direction of arrow A). This causes the second elastic portion 91 and the trigger inner wall 34 to separate in the axial direction, so that they are no longer facing each other in the radial direction. This makes the second elastic portion 91 deformable radially outward. The second free end 932 of the second elastic portion 91 (second arm portion 911) deforms radially outward with the second fixed end 931 as a pivot point, releasing the engagement between the projection 89 of the needle hub 183 and the second connection hole 95 of the holding member 20. In other words, the restriction on relative movement between the needle hub 183 and the holding member 20 by the third connection structure 743 is released, and the needle hub 183 and the holding member 20 become capable of relative movement in the axial direction.

[0119] At the first position of the trigger member 14, after the subcutaneous puncture of the puncture needle 181 and the fixation of the needle hub 183 to the skin S are completed, the user moves the drug delivery device 10A (housing 12) away from the surface of the skin S of the patient C, who is the target of the puncture, as shown in Figure 22. When patient C releases the pressure on the skin S against the drug delivery device 10A, the trigger member 14 is biased toward the tip (direction of arrow B) by the elastic force of the sleeve spring 153 (see Figure 2). The trigger member 14 moves relative to the housing 12 toward the second position, which is located toward the tip from the first position. Hereinafter, the operation of the trigger member 14 moving toward the tip from the first position to the second position will be referred to as the second operation.

[0120] Then, while the trigger member 14 performs the second action, the drug delivery device 10A is moved away from the surface of the patient C's skin S, so that the needle hub 183, which is fixed to the skin S, separates from the unit body 182 before the trigger member 14 reaches the second position. Specifically, when the unit body 182 separates from the skin S together with the trigger member 14, the magnetic force acting between the first magnet M1 and the second magnet M2 is interrupted because the needle hub 183 is fixed to the skin S by the adhesive material 56, and the needle hub 183 remains fixed to the skin S. The communication chamber 52 of the needle hub 183 is covered and sealed liquid-tight by the cap 57.

[0121] The second action of the trigger member 14 causes the unit body 182 to detach from the needle hub 183, thereby removing the inner needle 402 of the inner needle hub 44a from the outer needle 401 of the needle hub 183. Only the outer needle 401 of the puncture needle 181 is left subcutaneously in patient C. That is, the drug administration device 10A reaches the second position after the needle hub 183, which includes the outer needle 401 to be left in the skin S of patient C, and the device body 106, which consists of parts other than the needle hub 183, have separated. At this time, the separation of the outer needle 401 of the needle hub 183 and the unit body 182 causes the flexible tube 184 connecting the needle hub 183 and the unit body 182 to detach from the housing groove 54. The middle portion 603 of the flexible tube 184 extends in a spiral shape.

[0122] As shown in Figure 23, with the second operation of the trigger member 14, the slide member 14b moves relative to the sleeve body 122 toward the tip. That is, the engagement structure holding part 104 and the elastic part 102 move relative to each other in the axial direction. The base end of the slide member 14b moves toward the tip beyond the elastic part 102, resulting in the release position. The release position of the engagement structure holding part 104 is toward the tip beyond its initial position, and the slide member 14b and the elastic part 102 are no longer facing each other radially. The elastic part 102 is positioned toward the base end beyond the base end of the slide member 14b.

[0123] As a result, the elastic portion 102 is exposed radially outward from the base end of the engagement structure holding portion 104, and the elastic portion 102 becomes deformable radially outward. In other words, radial outward deformation of the elastic portion 102 is permitted. That is, the plunger holding structure 802 releases the plunger 22 from being held in the position before activation.

[0124] Since the plunger 22 is biased toward the tip by the elastic force of the resilient member 223, as shown in Figure 24, when the plunger 22 begins to move toward the tip, the plunger projection 100 pushes the claw portion 1021 of the elastic portion 102 radially outward, and the elastic portion 102 deforms radially outward with its base end as the pivot point. When the plunger projection 100 overcomes the claw portion 1021 of the elastic portion 102, the engagement state of the plunger 22 by the second engagement structure 882 is released. As a result, the plunger 22 begins to move toward the tip.

[0125] As shown in Figure 25, as the stopper 163 moves toward the tip along with the plunger 22, the drug solution R in the drug chamber 164 of the syringe 16 is pressed toward the tip by the stopper 163. As a result, the drug solution R flows from the tip of the syringe 16 through the connecting needle 421 to the flexible tube 184. The drug solution R flows from the tip 601 through the middle section 603 of the flexible tube 184 to the communication chamber 52 of the needle hub 183, and then is discharged subcutaneously into patient C through the tip of the outer needle 401. This initiates the administration of drug solution R subcutaneously into patient C. At this time, since the inner needle 402 has been removed from patient C, it is prevented that the drug solution R discharged from the outer needle 401 travels along the inner needle 402 and is administered subcutaneously from the tip of the inner needle 402, and furthermore, it is prevented that the drug solution R is administered to the tip position of the inner needle 402, which is inserted deeper than the tip of the outer needle 401.

[0126] Furthermore, the timing of administering the drug solution R subcutaneously to patient C from the tip of the outer needle 401 is not limited to when the inner needle 402 has moved relative to the outer needle 401 toward the proximal end and the inner needle 402 has been completely withdrawn from the outer needle 401. For example, the timing of administering the drug solution R from the outer needle 401 may be anytime during the second operation of the trigger member 14, after the tip of the inner needle 402 has moved relative to the outer needle 401 to a position where it is at least toward the proximal end than the tip of the outer needle 401.

[0127] In the second position of the trigger member 14, the tip of the trigger member 14 (needle cover 14a) in the drug administration device 10A moves to a position where it is further forward than the tip of the inner needle 402. As a result, the trigger member 14 completely covers the inner needle 402 of the device body 106. In the second position of the trigger member 14, a predetermined amount of drug solution R in the drug chamber 164 of the syringe 16 is administered subcutaneously.

[0128] After administration of the drug solution R is started, as shown in Figure 26A, the user can house the main body 106 of the separated drug solution administration device 10A in the housing 97. The housing 97 is capable of housing the main body 106, which is part of the drug solution administration device 10A, and can be attached, for example, to the outside of the user's clothing. By housing the main body 106 inside the housing 97 with the needle hub 183 in place on the user's skin S, the main body 106 can be kept in a position close to the user's body. In other words, the user does not need to hold the main body 106 of the drug solution administration device 10A while the drug solution R is being administered.

[0129] As described above, instead of keeping the main body 106 of the device in the housing 97 while administering the drug solution R, the main body 106 may be held, as shown in the drug solution administration device 101 in Figure 26B. This drug solution administration device 101 is equipped with a hook member 131 on the outside of the housing 12. The hook member 131 is L-shaped, protruding radially outward from the outer circumferential surface of the housing 12 and extending in the axial direction of the housing 12. By hooking the hook member 131 of the main body 106 onto the user's pocket, the main body 106 of the device can be held on the user's body while administering the drug solution R. In other words, the user does not need to hold the main body 106 while administering the drug solution R.

[0130] At the second position of the trigger member 14, after a predetermined time has elapsed since the administration of the drug solution R began, patient C checks the position of the stopper 163 inside the syringe 16 through the window 124 (see Figure 2) of the housing 12. When all of the drug solution R in the syringe 16 has been administered, the stopper 163 has moved to the tip of the cylindrical body 161. By confirming that the stopper 163 has reached the tip of the cylindrical body 161, patient C confirms that the administration of the drug solution R in the syringe 16 is complete. After the administration of the drug solution R subcutaneously to patient C is complete, the needle hub 183 is removed from the surface of the skin S. The used drug solution administration device 10A is disposed of in a predetermined manner.

[0131] The first embodiment provides the following effects.

[0132] As shown in Figure 4, the drug dispensing device 10A includes a plunger holding structure 802 that holds the plunger 22, which is biased toward the tip by the elastic force of a resilient member 223 provided inside the housing 12, in the pre-activation position. After the trigger member 14 performs a first action, it performs a second action, which releases the plunger 22 from the plunger holding structure 802, causing the plunger 22 to move relative to the syringe 16 toward the tip.

[0133] With this configuration, a simple setup is possible, and the plunger 22 is moved toward the syringe 16 in conjunction with the operation of the trigger member 14, thereby effectively administering the drug solution R.

[0134] The plunger holding structure 802 includes a first engagement structure 881 that can engage the locking member 801 and the trigger member 14 with each other, and a second engagement structure 882 that can engage the holding portion 98 and the plunger 22 with each other. The engagement state of the first engagement structure 881 is released by the first operation of the trigger member 14, and the engagement state of the second engagement structure 882 is released by the second operation of the trigger member 14.

[0135] With this configuration, the first action of the trigger member 14 makes the locking member 801 movable relative to the trigger member 14, and the second action of the trigger member 14 makes the plunger 22 movable relative to the tip.

[0136] As shown in Figure 7, the tip contact portion 922 provided on the trigger member 14 has a notch 96 in which a part of the circumferential direction of the trigger member 14 is cut out radially. The first operation of the trigger member 14 causes the lock member 801 to be pressed by the tip contact portion 922 and move toward the base end, and the lock member 801 rotates about its axis, so that the lock projection 90 and the notch 96 face each other in the axial direction, as shown in Figure 20, and the engagement state of the first engagement structure 881 is released.

[0137] With this configuration, the engagement state by the first engagement structure 881 can be effectively released by the first operation without moving the locking member 801 in the axial direction.

[0138] As shown in Figure 12, the holding portion 98 of the housing 12 is provided radially outward of the plunger 22 and has an elastic portion 102 that protrudes radially inward toward the plunger 22. In the initial position of the trigger member 14, the plunger projection 100 and the base end of the elastic portion 102 are in contact with the plunger 22 in the axial direction, and the engagement state of the second engagement structure 882 is released as the elastic portion 102 deforms radially outward (see Figure 24).

[0139] With this configuration, by providing a radially deformable elastic portion 102 in the holding portion 98, the engagement state of the plunger 22 can be effectively switched.

[0140] The trigger member 14 has an engagement structure holding portion 104 that faces radially outward of the elastic portion 102 in its initial position. The engagement structure holding portion 104 maintains the engaged state of the second engagement structure 882 from the initial position to the first position of the trigger member 14. The second operation of the trigger member 14 causes the engagement structure holding portion 104 and the elastic portion 102 to move relative to each other in the axial direction, thereby allowing radially outward deformation of the elastic portion 102.

[0141] With this configuration, the engagement state of the plunger 22 by the second engagement structure 882 can be effectively maintained from the initial position to the first position of the trigger member 14, while the plunger 22 can be made movable toward the tip when the trigger member 14 performs the second operation.

[0142] As shown in Figure 23, the engagement structure holding portion 104 moves to a release position that is further forward than the initial position by the second operation, and the elastic portion 102 is exposed radially outward from the base end of the engagement structure holding portion 104, making the elastic portion 102 deformable radially outward.

[0143] With this configuration, the second operation of the trigger member 14 causes the engagement structure holding portion 104 to disappear from the radially outward side of the elastic portion 102, thereby making the elastic portion 102 deformable radially outward.

[0144] As shown in Figure 10, the locking member 801 has an insertion portion 84 that is inserted into the plunger 22, and a contact structure 82 in which the insertion portion 84 and the plunger 22 abut against each other in the axial direction. The contact structure 82 has a contact portion 821 provided on the plunger 22 that abuts against the tip of the locking member 801 and prevents the locking member 801 from moving in the direction of the tip.

[0145] With this configuration, when the locking member 801 and the plunger 22 are assembled, the contact structure 82 allows for the axial positioning of the locking member 801 and the plunger 22.

[0146] In the initial position of the trigger member 14, the locking member 801 holds the engagement structure holding portion 104 in the direction of the base end rather than the tip end. With this configuration, the engagement structure holding portion 104 in the initial position can be effectively held in a predetermined position by the locking member 801.

[0147] The trigger member 14 has a base end contact portion 921 that abuts against the base end of the lock projection 90 in the axial direction. With this configuration, the base end contact portion 921 can effectively prevent the relative displacement of the trigger member 14 toward the tip of the lock member 801 in the initial position.

[0148] As shown in Figure 3, the trigger member 14 has a needle cover 14a with an opening 144 at its tip into which the puncture needle 181 can be exposed. The puncture needle 181 comprises a hollow cylindrical outer needle 401 and an inner needle 402 that can be inserted into the outer needle 401, and the puncture unit 18 has a needle hub 183 that holds the inner needle 402. A first action of the trigger member 14 exposes the puncture needle 181 to the outside through the opening 144 of the needle cover 14a, and a second action of the trigger member 14 detaches the needle hub 183 from the puncture unit 18, and the inner needle 402 is removed from the outer needle 401.

[0149] In this configuration, after the inner needle 402 is withdrawn from the outer needle 401 by the second action, the plunger 22 moves relative to the syringe 16 toward the tip, and the administration of the drug solution R begins.

[0150] As shown in Figure 27, the drug administration device 10B according to the second embodiment comprises a puncture unit 18B and an activation prevention mechanism 80B. As shown in Figure 28, the puncture unit 18B comprises a puncture needle 181B and a needle hub 183B that holds the puncture needle 181B.

[0151] The puncture needle 181B is designed to allow the administration of drug solution R subcutaneously (in vivo) to patient C (see Figure 32). 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 in place by the needle hub 183B.

[0152] As shown in Figure 29, the activation prevention mechanism 80B comprises an elastic structure 110 and an elastic deformation prevention part 112 capable of preventing the elastic deformation of the elastic structure 110. The elastic structure 110 is provided on the rod body 221B of the plunger 22B. As shown in Figure 30, the elastic structure 110 comprises a plurality of elastic pieces 111. Each elastic piece 111 is arranged in parallel in the circumferential direction of the rod body 221B. The tip of each elastic piece 111 is supported by the rod body 221B. Each elastic piece 111 has elasticity that allows the base end, which is the free end, to be elastically deformable radially inward from the tip end, which is the fixed end, and to be elastically restored radially outward. The base end of each elastic piece 111 has a claw portion 114 that protrudes radially outward. As shown in Figure 29, in the pre-activation position of the plunger 22B, the claw portion 114 of each elastic piece 111 is engaged with the locking portion 116 of the sleeve body 122B. The locking portion 116 protrudes radially inward from the inner circumferential surface of the sleeve body 122B. In the position before the plunger 22B is activated, the locking portion 116 is positioned towards the tip of the claw portion 114. The locking portion 116 prevents the plunger 22B from moving toward the tip.

[0153] The elastic deformation prevention portion 112 is the insertion portion 84B of the locking member 801B. In the initial position of the trigger member 14, the insertion portion 84B is inserted into the inside of the rod body 221B. In the initial position of the trigger member 14, radial inward deformation of each elastic piece 111 is prevented by the insertion portion 84B. The activation prevention mechanism 80B prevents the plunger 22B from moving toward the tip in the initial position of the trigger member 14. The plunger 22B is held in the pre-activation position.

[0154] When the trigger member 14 performs a first operation from its initial position, the locking member 801B moves towards the proximal end. The locking member 801B moves relative to the plunger 22B towards the proximal end. As the insertion portion 84B detaches from the rod body 221B towards the proximal end, each elastic piece 111 of the elastic structure 110 becomes deformable radially inward. As a result, the plunger 22B moves towards the tip due to the elastic force of the resilient member 223, and the movement of the plunger 22B toward the tip pushes the drug solution R in the drug chamber 164 toward the tip by the stopper 163. As shown in Figure 32, the drug solution R in the syringe 16 is administered subcutaneously to patient C through the connecting needle 421, the flexible tube 184, the communication chamber 52, and the puncture needle 181B.

[0155] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the spirit of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

Claims

1. A drug delivery device comprising: a housing; a syringe having a cylindrical body housed within the housing and filled with a drug solution; a puncture needle communicating with the inside of the cylindrical body for administering the drug solution into a living body; a trigger member that moves relative to the housing in the proximal direction when pressed against the target of puncture in the living body; and a plunger provided inside the housing, which is capable of moving relative to the syringe in the tip direction as the trigger member moves relative to the proximal direction, and which discharges the drug solution from the puncture needle when it moves in the tip direction, wherein the device comprises a plunger holding structure that holds the plunger, which is biased toward the tip direction by the elastic force of an elastic member provided inside the housing, in a pre-activation position, and the trigger member is capable of performing: a first operation of moving relative to the housing from the initial position toward the proximal direction toward a first position provided toward the proximal direction from the initial position; and a second operation of moving relative to the housing from the first position toward the tip direction toward a second position provided toward the tip direction from the first position. A drug dispensing device wherein, after the trigger member performs the first operation, the second operation is performed, thereby releasing the plunger from the plunger holding structure and causing the plunger to move relative to the syringe in the tip direction.

2. A drug dispensing device according to claim 1, comprising: a locking member movably provided inside the housing; and a holding portion provided in the housing for holding the plunger in the initial position, wherein the plunger holding structure comprises: a first engagement structure capable of engaging the locking member and the trigger member with each other; and a second engagement structure capable of engaging the holding portion and the plunger with each other, wherein the engagement state of the first engagement structure is released by the first operation of the trigger member, and the engagement state of the second engagement structure is released by the second operation of the trigger member.

3. A drug dispensing device according to claim 2, wherein the locking member has a locking projection that protrudes outward, the trigger member has a tip contact portion that abuts against the tip of the locking projection in the axial direction of the plunger, the tip contact portion has a notch in which a part of the circumferential direction of the trigger member is cut out radially, and by the first operation of the trigger member, the locking member is pressed against the tip contact portion and moves toward the base end, and the locking member rotates about the axis of the locking member, so that the locking projection and the notch face each other in the axial direction, and the engagement state of the first engagement structure is released.

4. A drug dispensing device according to claim 3, wherein the plunger has a plunger projection that protrudes outward, the holding portion is provided radially outward of the plunger and has an elastic portion that protrudes radially inward toward the plunger, in the initial position the plunger projection and the base end of the elastic portion are in contact with the plunger in the axial direction, and the engagement state of the second engagement structure is released when the elastic portion deforms radially outward.

5. A drug dispensing device according to claim 4, wherein the trigger member has an engagement structure holding portion facing radially outward of the elastic portion in the initial position, the engagement structure holding portion maintains the engaged state of the second engagement structure from the initial position to the first position, and the second operation of the trigger member causes the engagement structure holding portion and the elastic portion to move relative to each other in the axial direction, thereby allowing deformation of the elastic portion radially outward.

6. A drug dispensing device according to claim 5, wherein the engagement structure holding portion moves to a release position that is further forward than the initial position by the second operation, and the elastic portion is exposed radially outward from the base end of the engagement structure holding portion, thereby allowing the elastic portion to be deformed radially outward.

7. A drug dispensing device according to claim 6, wherein the locking member has an insertion portion that is inserted into the plunger, the insertion portion and the plunger have a contact structure in which they contact each other in the axial direction, and the contact structure has a contact portion provided on the plunger that contacts the tip of the locking member to prevent the locking member from moving in the direction of the tip.

8. A drug dispensing device according to claim 7, wherein, in the initial position of the trigger member, the locking member holds the engagement structure holding portion in the direction of the proximal end rather than the tip position.

9. A drug dispensing device according to claim 8, wherein the trigger member has a base end contact portion that contacts the base end of the lock projection in the axial direction.

10. A drug administration device according to any one of claims 1 to 9, wherein the trigger member has a needle cover having an opening at its tip from which the puncture needle can be exposed, and has a puncture unit having the puncture needle and a connecting portion that can communicate with the inside of the cylindrical body by being connected to the tip of the syringe, the puncture needle comprises a hollow cylindrical outer needle and an inner needle that can be inserted into the outer needle, the puncture unit has a needle hub that holds the inner needle, the first operation of the trigger member causes the puncture needle to be exposed to the outside from the opening of the needle cover, and the second operation of the trigger member causes the needle hub to detach from the puncture unit and the inner needle to be removed from the outer needle.

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