Drug solution administration device and drive unit

Abstract

A drug solution administration device (10) comprises: a cartridge (16) having a reservoir (22) and a plunger (24); and a drive unit (18) to / from which the cartridge (16) can be attached / detached. The drive unit (18) comprises a detachment prevention mechanism (66) provided to an inner housing (38) so as to be openable and closable. The detachment prevention mechanism (66), in an open position, allows detachment of the cartridge (16) from the inner housing (38). The detachment prevention mechanism (66), in a closed position, prevents detachment of the cartridge (16) mounted to a mounting part (20), from the inner housing (38).

Description

Drug solution administration device and drive unit

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

[0002] Japanese Patent No. 5506780 discloses a drug solution administration device including a reservoir for filling a drug solution. The drug solution administration device includes a reusable part and a disposable part. The drug solution administration device is used with the reusable part and the disposable part assembled to each other. The disposable part includes a piston inserted into a drug chamber filled with the drug solution and a piston rod extending axially from the piston. The reusable part includes a drive mechanism. In a state where the reusable part and the disposable part are assembled, the drive mechanism and the piston rod are connected. By driving the drive mechanism, the piston moves in the drug chamber and the drug solution is administered to the living body.

[0003] Japanese Patent No. 5506780

[0004] In a drug solution administration device such as that disclosed in Japanese Patent No. 5506780, when removing the reservoir from the housing of the disposable part and replacing it with a new reservoir, there is a problem that the attachment / detachment operation is complicated.

[0005] An object of the present disclosure is to solve the above-described problems.

[0006] (1) A first aspect of the present disclosure is a drug solution administration device including a cartridge having a reservoir capable of accommodating a drug solution and a plunger provided movably in the axial direction of the reservoir to discharge the drug solution from the reservoir, and a drive unit having a drive mechanism for driving the plunger in the axial direction, the cartridge being detachable. The drive unit includes an internal housing having a mounting portion to which the cartridge is mounted, and a detachment prevention mechanism provided to the internal housing so as to be openable and closable, the detachment prevention mechanism allowing detachment of the cartridge from the mounting portion in an open position and preventing detachment of the cartridge mounted to the mounting portion from the internal housing in a closed position.

[0007] With this drug dispensing device, when attaching or detaching a cartridge to the drive unit, the detachment prevention mechanism can be opened and closed, making it easy to remove and install the cartridge.

[0008] (2) In the drug administration device described in (1) above, the detachment prevention mechanism may include a prevention member that is rotatably supported in the internal housing.

[0009] With this configuration, the mounting portion can be effectively opened and closed by rotating the blocking member relative to the internal housing.

[0010] (3) In the drug administration device described in (2) above, the blocking member may cover only a part of the cartridge from the direction of detachment of the cartridge.

[0011] This configuration allows for easy visual inspection of the medication solution inside the cartridge when it is attached to the drive unit, thereby enhancing safety during the use of the medication dispensing device.

[0012] (4) In the drug administration device described in (3) above, the detachment prevention mechanism may include a biasing member that causes the preventing member to move in a direction away from the mounting portion.

[0013] This configuration allows the blocking member to be easily opened by the biasing force of the biasing member when removing the cartridge from the drive unit.

[0014] (5) In the drug solution dispensing device described in (3) or (4) above, the blocking member may have a holding portion that faces the reservoir in the axial direction in the closed position and into contact with a part of the reservoir.

[0015] This configuration effectively suppresses the movement of the liquid medication towards the tip of the reservoir while it is filled with the medication.

[0016] (6) In the drug administration device described in (3) or (4) above, a locking mechanism may be provided to prevent the opening operation of the detachment prevention mechanism when the detachment prevention mechanism is in the closed position.

[0017] This configuration effectively prevents the release prevention mechanism from accidentally opening when the cartridge is in the closed position.

[0018] (7) In the drug solution dispensing device described in (6) above, the blocking member is a cantilever structure comprising a support end having a support portion supported by the internal housing and a free end provided at the end opposite to the support end in the extending direction of the blocking member, and the locking mechanism may comprise a lock pin movably provided on the blocking member and capable of protruding outward from the free end, a lock hole provided in the internal housing into which the lock pin is inserted in the closed position, and a locking biasing member that biases the lock pin toward the lock hole.

[0019] With this configuration, the locking state of the blocking member can be effectively maintained by the biasing force of the locking biasing member when the blocking member is in the closed position.

[0020] (8) In the drug administration device described in (7) above, the lock mechanism has a release mechanism that can release the locked state of the release prevention mechanism, the release mechanism comprises a release operating member that is exposed to the outer surface of the prevention member and movable, and a link mechanism that connects the release operating member and the lock pin and interlocks the lock pin when the release operating member is operated, the release operating member is in a locked position that has moved toward the free end side along the extending direction of the prevention member, and the release operating member may be moved toward the support end side in the extending direction of the prevention member, thereby moving toward the unlocked position via the link mechanism toward the lock pin that has released from the lock hole.

[0021] This configuration allows the locking mechanism preventing detachment to be effectively released by operating the release operation member.

[0022] (9) In the drug administration device described in (8) above, the release operating member comprises a rotatable support portion rotatably supported by the blocking member, and a release operating portion located on the opposite side of the rotatable support portion in a direction that intersects with the axis of rotation of the rotatable support portion and intersects with the direction of movement of the lock pin, and exposed to the outside of the blocking member so as to be released by the user, wherein in the locked position, the release operating portion is located along the extending direction of the blocking member, and in order to move from the locked position to the unlocked position, the release operating member may rotate with the rotatable support portion as a pivot point by moving the release operating member toward the support end.

[0023] With this configuration, when the lock state is released by the release mechanism, the release operation part is moved toward the support part that is the center of the opening movement of the blocking member, thereby releasing the lock. The user can easily understand the lock release operation intuitively.

[0024] (10) In the drug solution dispensing device described in (1) above, the cartridge is provided with a removal assist structure for moving the cartridge away from the mounting portion when removing the cartridge that has been mounted on the mounting portion, and the removal assist structure may be provided on the outer circumference of the reservoir and include a protruding portion that protrudes from the outer circumference.

[0025] This configuration allows the user to easily remove a cartridge from the drive unit's mounting section by pushing the protruding part in the direction of cartridge removal, thereby moving the cartridge within the mounting section.

[0026] (11) In the drug dispensing device described in (10) above, the protruding portion may extend beyond one surface of the outer wall of the inner housing in a direction that causes the reservoir to detach from the drive unit.

[0027] This configuration makes it easier for the user to remove the cartridge by pressing the protruding part.

[0028] (12) In the drug administration device described in (2) above, the outer wall portion of the inner housing has an opening that communicates with the mounting portion, and the blocking member may be arranged so as to intersect the opening direction of the opening when in the closed position.

[0029] This configuration allows for effective attachment and detachment of the cartridge to and from the mounting section through the opening.

[0030] (13) The drug administration device described in (1) above has a holder for holding a cannula to be inserted into a living body, and a locking mechanism that prevents the opening operation of the detachment prevention mechanism when the detachment prevention mechanism is in the closed position, the locking mechanism is provided so as to be exposed to the outer surface of the prevention member and has a release operation member that can release the locked state of the detachment prevention mechanism, and the release operation member does not need to be visible from the outside when the drive unit is mounted on the holder.

[0031] This configuration effectively prevents users from accidentally operating the release mechanism when attaching the drug delivery device to the body surface, as the release mechanism is covered.

[0032] (14) A second aspect of the present disclosure is a drive unit for which a cartridge having a reservoir capable of containing a liquid medicine and a plunger disposed in the reservoir is detachable, comprising: a drive mechanism that biases the plunger toward the tip by moving in the axial direction of the reservoir; an internal housing having a mounting portion on which the cartridge is mounted; and a detachment prevention mechanism provided in the internal housing so as to be openable and closable, which in the open position allows the cartridge to detach from the mounting portion and in the closed position prevents the cartridge mounted on the mounting portion from detaching from the internal housing.

[0033] With this drive unit, when attaching or detaching a cartridge to the drive unit, the detachment prevention mechanism can be opened and closed, making it easy to remove and install the cartridge.

[0034] According to this disclosure, when attaching or detaching a cartridge to or from the drive unit, the cartridge can be easily removed and attached by opening and closing the detachment prevention mechanism.

[0035] Figure 1 is an external perspective view of a drug administration device according to the first embodiment of this disclosure. Figure 2 is an exploded perspective view of the pump section of the drug administration device shown in Figure 1. Figure 3 is a perspective view of the pump section of the drug administration device viewed from below. Figure 4 is a partially cutaway plan view of the pump section of Figure 3. Figure 5 is a cross-sectional view along the line V-V in Figure 4. Figure 6 is a cross-sectional view along the line VI-VI in Figure 5. Figure 7 is a first explanatory diagram showing the drug administration device in use. Figure 8 is a perspective view of the drive mechanism including the plunger pressing section. Figure 9 is an enlarged perspective view showing the tip of the drive unit. Figure 10 is a cross-sectional view along the line X-X in Figure 9. Figure 11 is a first explanatory diagram showing the operation of the detachment prevention mechanism shown in Figure 10. Figure 12 is a second explanatory diagram showing the drug administration device in use. Figure 13 is a cross-sectional explanatory diagram showing the drug administration device attached to a living body. Figure 14 is a second explanatory diagram showing the operation of the detachment prevention mechanism. Figure 15 is a third explanatory diagram showing the drug administration device in use. Figure 16 is a fourth explanatory diagram showing the state of use of the drug dispensing device. Figure 17 is a perspective view of the pump section of the drug dispensing device according to the second embodiment of this disclosure. Figure 18 is an exploded perspective view of the pump section shown in Figure 17. Figure 19 is a perspective view of the reservoir. Figure 20 is a front view of the reservoir. Figure 21 is a cross-sectional view of the pump section. Figure 22 is a partially cutaway plan view of the pump section. Figure 23 is a cross-sectional view along the line XXIII-XXIII in Figure 21. Figure 24 is a cross-sectional view of the release prevention mechanism and the locking mechanism. Figure 25 is a cross-sectional view along the line XXV-XXV in Figure 24. Figure 26 is an explanatory diagram showing the state of use of the drug dispensing device shown in Figure 17.

[0036] The drug delivery device 10 according to the first embodiment is used to deliver a drug solution M to a living body B (e.g., a patient) by being attached to the surface of a target area (e.g., skin S) of the living body B (see Figure 13). Specifically, the drug delivery device 10 is fixed to the skin S of the living body B by an adhesive sheet 141 provided on the lower surface of the holder 14, for example. Hereinafter, "downward" or "lower surface" refers to the direction or surface facing the living body B when the drug delivery device 10 is fixed to the living body B. "Upward" or "upper surface" refers to the direction or surface facing away from the living body B when the drug delivery device 10 is fixed to the living body B.

[0037] As shown in Figure 1, the drug dispensing device 10 comprises a pump unit 12 and a holder 14. The pump unit 12 is detachably attached to the holder 14.

[0038] As shown in Figure 2, the pump unit 12 comprises a cartridge 16 and a drive unit 18. The pump unit 12 is used with the cartridge 16 and the drive unit 18 assembled together. The drive unit 18 is a reusable part, and the cartridge 16 is a disposable part.

[0039] The drug dispensing device 10 is operated by a handset (not shown). The handset communicates with the communication unit of the drive unit 18. The handset may be a dedicated terminal or a smartphone or other device with a dedicated application downloaded.

[0040] As shown in Figure 3, the cartridge 16 is detachably mounted on the mounting portion 20 of the drive unit 18. As shown in Figure 4, the cartridge 16 comprises a reservoir 22, a plunger 24, and a flow path forming member 26. The cartridge 16 is provided in a sterilized state, contained in blister packaging or the like.

[0041] The reservoir 22 is capable of containing the chemical solution M (see Figure 7). As shown in Figure 5, the reservoir 22 comprises a reservoir body 221, a reservoir opening 222, and a guide portion 223.

[0042] The reservoir main body 221 is formed in a syringe barrel shape and has an internal medicine chamber 28 into which the medicine solution M is introduced (see FIG. 7). When viewed from the axial direction of the reservoir 22, the cross section of the reservoir main body 22 is substantially circular (see FIG. 11). Note that the cross section of the reservoir main body 221 is not limited to being circular.

[0043] As shown in FIG. IV, the tip of the reservoir main body 221 has a medicine solution flow-through part 30. The medicine solution flow-through part 30 communicates with the medicine chamber 28 (see FIG. 5). The medicine solution flow-through part 30 extends in a direction intersecting the axis of the reservoir main body 221. The medicine solution flow-through part 30 can introduce the medicine solution M from outside the reservoir 22 into the reservoir 22. The medicine solution flow-through part 30 can lead out the medicine solution M in the reservoir 22 to the outside of the reservoir 22.

[0044] As shown in FIG. 5, the reservoir opening 222 is provided at the base end part of the reservoir main body 221. The reservoir opening 222 opens in the base end direction at the base end part of the reservoir main body 221.

[0045] The guide part 223 is formed in a disk shape and provided at the base end part of the reservoir main body 221. The guide part 223 covers the reservoir opening 222. As shown in FIG. 6, the guide part 223 has a guide hole 32. The guide hole 32 penetrates the guide part 223 in the axial direction of the plunger 24. A part of the plunger 24 and the drive mechanism 40 is inserted into the guide hole 32 so as to be movable with respect to the guide hole 32. In the present embodiment, a pair of guide holes 32 are provided, and the pair of guide holes 32 are separated from each other in a direction intersecting the axial direction of the reservoir 22, but is not limited thereto. For example, there may be one guide hole 32, or three or more guide holes 32.

[0046] The base end part of the guide part 223 has an annular seal member 34. The seal member 34 is attached to a groove formed on the outer periphery of the base end part of the guide part 223. The seal member 34 projects radially outward from the outer periphery of the base end part. When the cartridge 16 is housed in the mounting part 20 of the drive unit 18, the seal member 34 contacts the inner surface of the fitting part 203 of the mounting part 20 described later.

[0047] As shown in FIG. 6, in the initial state (ready-to-use state), all of the plunger 24 is housed inside the reservoir 22. The plunger 24 is provided so as to be movable in the axial direction of the reservoir 22. The plunger 24 includes a plunger body 241 and a pair of plunger rods 242. The plunger body 241 is inserted into the reservoir body 221 of the reservoir 22 in a liquid-tight manner. The cross-section of the plunger body 241 is circular corresponding to the cross-section of the reservoir body 221, and a plunger seal member 243 is attached to the outer periphery of the tip portion. Thereby, a sealed medicine chamber 28 is formed between the reservoir body 221 and the tip of the plunger body 241 (see FIG. 7). The medicine chamber 28 can be filled with the liquid medicine M.

[0048] The plunger rod 242 extends from the plunger body 241 in the proximal direction. The pair of plunger rods 242 are arranged parallel to each other with a separation in the radial direction of the plunger body 241. Each of the pair of plunger rods 242 can be inserted into the guide hole 32 of the guide portion 223.

[0049] When the liquid medicine M is not filled in the reservoir 22 (medicine chamber 28), the plunger 24 is housed inside the reservoir 22. In the state where the plunger 24 is pushed to the tip direction, the length of the plunger 24 does not protrude from the reservoir 22. That is, the plunger rod 242 does not protrude in the proximal direction from the proximal end portion of the guide hole 32. As shown in FIG. 7, when the liquid medicine M is filled in the medicine chamber 28 of the reservoir 22, the plunger 24 is pushed and moved in the proximal direction by the liquid medicine M. At this time, the plunger rod 242 moves in the proximal direction from the proximal end of the reservoir 22 through the guide hole 32. After the liquid medicine M is filled in the medicine chamber 28 of the reservoir 22, the plunger 24 moves in the tip direction of the reservoir 22 by the drive mechanism 40, thereby discharging the liquid medicine M from the reservoir 22.

[0050] As shown in Figure 4, the flow path forming member 26 is positioned on the outer circumference of the reservoir body 221. The flow path forming member 26 is positioned parallel to the reservoir 22 and fixed to the reservoir body 221. The flow path forming member 26 extends along the axial direction of the reservoir 22. The flow path forming member 26 has a flow passage 261 through which the drug solution M can flow. The flow passage 261 is formed along the extending direction of the flow path forming member 26. The tip of the flow path forming member 26 faces the drug solution flow section 30. The tip of the flow passage 261 is connected to the drug solution flow section 30, allowing them to communicate with each other. The base end of the flow path forming member 26 is positioned in the cannula unit housing section 50 of the internal housing 38. The base end of the flow passage 261 can be connected to the cannula unit 94, which will be described later (see Figure 13).

[0051] As shown in Figure 3, the cartridge 16 further includes an extraction assist structure 36. The extraction assist structure 36 is provided to move the cartridge 16 away from the mounting portion 20 when the cartridge 16 mounted on the mounting portion 20 of the drive unit 18 is extracted. The extraction assist structure 36 includes a protruding portion 361. The protruding portion 361 is provided on the outer circumference of the reservoir 22. As shown in Figure 5, the protruding portion 361 is provided on the guide portion 223. The protruding portion 361 is a convex portion that protrudes radially outward from the outer circumference of the guide portion 223 of the reservoir 22. The protruding portion 361 protrudes outward from the outer wall portion 382 of the internal housing 38 in the drive unit 18, which will be described later. Note that the protruding portion 361 is not limited to protruding outward from the outer wall portion 382 of the internal housing 38. For example, the protruding portion 361 may be flush with the outer wall portion 382, ​​or positioned inside the internal housing 38 beyond the outer wall portion 382. The protruding portion 361 only needs to be exposed to the outside through the opening 381. Since the cartridge 16 has a small capacity of about 2 to 3 mL, the removal assist structure 36 makes it easy to attach and detach.

[0052] As shown in Figure 3, the removal assist structure 36 may further include a tab member 362. The tab member 362 is formed in a sheet shape and extends along the axial direction of the reservoir 22. The tip of the tab member 362 is fixed to the tip of the reservoir 22. The tab member 362 extends toward the base end of the reservoir 22. The base end of the tab member 362 is positioned on the outer circumference of the reservoir body 221. At least the base end of the tab member 362 is exposed to the outside through the opening 381 of the internal housing 38. The base end of the tab member 362 is a free end that is not fixed to the reservoir 22 and is provided so that it can be grasped by the user. By providing the tab member 362, it is possible to make it easier to remove the cartridge 16 (reservoir 22) from the drive unit 18 even if the plunger 24 protrudes toward the base end of the reservoir 22.

[0053] Note that the cartridge 16 is not limited to having an extraction assist structure 36. For example, the cartridge 16 mounted on the mounting section 20 may be removed to the outside by the user directly grasping it.

[0054] As shown in Figure 4, the drive unit 18 comprises an internal housing 38, a drive mechanism 40, a power supply unit 42, and an external housing 44.

[0055] The internal housing 38 comprises a mounting portion 20 and an opening 381. A cartridge 16 is detachably mounted in the mounting portion 20. The mounting portion 20 is formed recessed in the thickness direction from the outer wall portion 382 of the internal housing 38 (see Figure 5). The outer wall portion 382 of the internal housing 38 is the surface facing the holder 14 attached to the skin S of the living body B when the drug solution M is administered to the living body B using the drug solution administration device 10 (see Figure 13). The mounting portion 20 is a housing portion 383 capable of housing the cartridge 16 inside. Note that the mounting portion 20 is not limited to a housing portion 383 recessed from the outer wall portion 382 of the internal housing 38. For example, the mounting portion 20 may be provided in the outer wall portion 382 of the internal housing 38.

[0056] As shown in Figure 4, the mounting section 20 comprises a reservoir mounting section 201 and a flow path member mounting section 202. The reservoir mounting section 201 is positioned close to the tip of the internal housing 38. The reservoir mounting section 201 comprises a housing bottom section 461 (see Figure 5) and a pair of housing side sections 462 (see Figure 6). The housing bottom section 461 is formed in a circular arc shape in cross-section and is positioned away from the outer wall section 382 (see Figure 10). Each of the pair of housing side sections 462 extends from the housing bottom section 461 toward the outer wall section 382 (see Figure 10). When the cartridge 16 is mounted on the mounting section 20, the reservoir 22 is housed in the reservoir mounting section 201. The base end of the reservoir mounting section 201 has a fitting section 203 into which the guide section 223 is fitted (see Figure 5). The flow path member mounting section 202 is provided on the side of the reservoir mounting section 201. When the cartridge 16 is mounted on the mounting section 20, the flow path forming member 26 is housed in the flow path member mounting section 202.

[0057] As shown in Figure 3, the internal housing 38 has an opening 381. The opening 381 opens into the outer wall portion 382 and communicates with the mounting portion 20. As shown in Figure 4, the opening 381 has a first opening 481 that opens into the outer wall portion 382 and a second opening 482 that opens into the tip of the internal housing 38. The first opening 481 and the second opening 482 are connected. The cartridge 16 can be attached to and detached from the mounting portion 20 through the opening 381. When the cartridge 16 is mounted on the mounting portion 20, a part of the cartridge 16 is exposed to the outside through the opening 381 (see Figure 3).

[0058] As shown in Figure 3, the internal housing 38 further comprises a cannula unit housing 50, a supported portion 52, and a holder detection portion SB. The cannula unit housing 50 is formed recessed from the outer wall portion 382 of the internal housing 38. The cannula unit housing 50 is located near the proximal end of the outer wall portion 382 of the internal housing 38. When the drug administration device 10 is attached to the holder 14, the cannula unit 94 provided on the holder 14 is housed in the cannula unit housing 50 (see Figure 13). The supported portion 52 is provided at the tip of the internal housing 38 and supports the detachment prevention mechanism 66, which will be described later. The holder detection portion SB is provided on the outer wall portion 382 of the internal housing 38. After the pump portion 12 is attached to the holder 14, the drug administration device 10 becomes ready to start administering the drug M by detecting the presence of a projection (not shown) provided on the holder 14.

[0059] As shown in Figure 4, the drive mechanism 40 is provided inside the internal housing 38. The drive mechanism 40 drives the plunger 24 in the axial direction when the cartridge 16 is attached to the drive unit 18. The drive mechanism 40 comprises a drive unit 401, a shaft 402, and a plunger pressing unit 403.

[0060] The drive unit 401 includes a motor 54 having a drive shaft 541. However, the drive unit 401 is not limited to the motor 54; it can be any rotational drive source. The shaft 402 has threads formed on its outer surface. The shaft 402 is rotatably supported in the internal housing 38. The shaft 402 is positioned facing the plunger 24. The shaft 402 is connected to the drive shaft 541 of the motor 54 via a gear mechanism 56. When the motor 54 is driven, the shaft 402 is rotationally driven via the drive shaft 541 and the gear mechanism 56. That is, the driving force of the drive unit 401 is transmitted to the shaft 402 via the gear mechanism 56.

[0061] The plunger pressing portion 403 moves toward the tip when driven by the drive unit 401, contacts the plunger 24, and pushes the plunger 24 toward the tip. With the cartridge 16 mounted on the drive unit 18, the plunger pressing portion 403 is positioned toward the base end of the plunger 24.

[0062] As shown in Figure 8, the plunger pressing portion 403 comprises a base end member 581, a tip end member 582, and an intermediate member 583. As shown in Figure 6, the base end member 581 is positioned at the base end of the plunger pressing portion 403. The base end member 581 is formed from, for example, a resin material. The base end member 581 has a shaft hole 60 into which the shaft 402 is screwed.

[0063] The tip-side member 582 is positioned towards the tip of the base-side member 581. The tip-side member 582 is formed from, for example, a resin material. The tip-side member 582 includes a pair of connecting arms 62. Each of the pair of connecting arms 62 protrudes toward the base end and is arranged parallel to each other. The end of each connecting arm 62 is provided with a claw portion 621. The pair of connecting arms 62 are inserted into a pair of connecting holes 64 of the base-side member 581. With the pair of connecting arms 62 inserted into the connecting holes 64, each claw portion 621 engages with the end face of the base-side member 581. This connects the base-side member 581 and the tip-side member 582 to each other in the axial direction of the shaft 402.

[0064] The intermediate member 583 is positioned between the base end member 581 and the tip end member 582. The intermediate member 583 is formed in the shape of a plate from, for example, a metal material. The intermediate member 583 is sandwiched between the base end member 581 and the tip end member 582 by connecting them to each other (see Figure 5).

[0065] As shown in Figure 6, in the initial state before the drive mechanism 40 is driven, when the drive unit 18 and cartridge 16 are assembled, the plunger pressing portion 403 of the drive mechanism 40 and the plunger 24 (plunger rod 242) are spaced apart from each other in the axial direction.

[0066] As the motor 54 drives, the shaft 402 rotates, causing the plunger pressing portion 403, including the base end member 581, to move toward the tip (towards the plunger 24). The plunger pressing portion 403 (tip end member 582) pushes the base end of the plunger rod 242 toward the tip (see Figure 12).

[0067] Furthermore, the plunger pressing portion 403 is not limited to being composed of three parts: a base member 581, a tip member 582, and an intermediate member 583. For example, the plunger pressing portion 403 may be configured such that the base member 581 and the tip member 582 are integrally formed, and a metal member corresponding to the intermediate member 583 is built inside. In this case, the plunger pressing portion 403 is preferably formed by insert molding. Also, the plunger pressing portion 403 is not limited to a configuration including a metal member; for example, the plunger pressing portion 403 may be formed solely from a resin material.

[0068] As shown in Figure 4, the power supply unit 42 is mounted on the circuit board K housed in the internal housing 38. The power supply unit 42 supplies power to the drive unit 401 of the drive mechanism 40 via the circuit board K. The power supply unit 42 includes a battery.

[0069] As shown in Figure 13, the outer housing 44 is provided so as to cover the upper part of the inner housing 38. The outer housing 44 is fixed to the inner housing 38 while covering the upper part of the inner housing 38. The inner housing 38 and the outer housing 44 are fixed together via a housing seal 45 (see Figure 10). As a result, the drive mechanism 40 and the power supply unit 42 are housed in the space between the inner housing 38 and the outer housing 44 (see Figures 4 and 5).

[0070] As shown in Figure 3, the drive unit 18 is further equipped with a detachment prevention mechanism 66.

[0071] The detachment prevention mechanism 66 is provided to the outer wall portion 382 of the inner housing 38 so as to be openable and closable. As shown in Figure 4, the detachment prevention mechanism 66 is provided at the tip of the inner housing 38. The detachment prevention mechanism 66 is provided so as to be switchable between an open position and a closed position by opening and closing it. In the closed position of the detachment prevention mechanism 66, the detachment prevention mechanism 66 prevents the cartridge 16 mounted on the mounting portion 20 from detaching from the inner housing 38. In the closed position, the detachment prevention mechanism 66 closes a part of the opening 381 of the inner housing 38. On the other hand, in the open position of the detachment prevention mechanism 66, the detachment prevention mechanism 66 allows the cartridge 16 to detach from the mounting portion 20 (see Figure 11).

[0072] As shown in Figure 9, the release prevention mechanism 66 comprises a stopping member 68, a biasing member 70, and a locking mechanism 72 (see Figure 10). The stopping member 68 extends in the width direction of the internal housing 38. As shown in Figure 4, the width direction of the internal housing 38 intersects with the axial direction of the plunger 24 and the thickness direction of the internal housing 38.

[0073] The blocking member 68 is rotatably supported by the internal housing 38. The blocking member 68 comprises a support end 681 and a free end 682. The support end 681 is provided at one end in the extending direction of the blocking member 68. The support end 681 has a support portion 683. As shown in Figure 4, the support portion 683 is rotatably supported by a support pin 74 perpendicular to the extending direction of the blocking member 68 on the supported portion 52 of the internal housing 38. At the tip of the internal housing 38, the support end 681 is supported at the center of the internal housing 38 in the width direction. The free end 682 is provided at the end of the blocking member 68 opposite to the support end 681 in the extending direction. The free end 682 is positioned at the widthwise end of the internal housing 38. The blocking member 68 has a cantilever structure in which the free end 682 side is rotatable with the support portion 683 as the pivot point (see Figure 16). In the closed position of the blocking member 68, the blocking member 68 is positioned so as to intersect with the opening direction of the opening 381 of the internal housing 38. Note that the blocking member 68 is not limited to being rotatably supported by the internal housing 38. For example, the blocking member 68 may be slidably supported in the width direction of the internal housing 38, and the opening 381 may be opened and closed by sliding the blocking member 68.

[0074] As shown in Figure 9, the blocking member 68 further comprises a main body portion 761, a side wall portion 762, and a holding portion 763 (see Figure 7). The main body portion 761 is formed in a flat plate shape from the support end 681 to the free end 682. The side wall portion 762 is provided at the tip of the blocking member 68. The side wall portion 762 is formed in a wall shape that protrudes in the thickness direction from the tip of the main body portion 761. The holding portion 763 is provided inside the main body portion 761 and the side wall portion 762. The holding portion 763 protrudes from the inner surface of the side wall portion 762 toward the base end. As shown in Figure 5, the holding portion 763 faces the reservoir 22 in the axial direction when the blocking member 68 is in the closed position. When the blocking member 68 is in the closed position, the tip of the reservoir 22 (chemical liquid flow portion 30) can come into contact with the holding portion 763. The retaining portion 763 prevents the reservoir 22 from moving toward the tip.

[0075] When the blocking member 68 is in the closed position, the annular sealing member 34 located on the base end side of the reservoir 22 is in close contact with the inner surface of the fitting portion 203. As a result, the inside of the drive unit 18 is sealed, and the electronic equipment inside the drive unit 18 is protected from the ingress of liquids, etc.

[0076] The retaining portion 763 may be configured to always contact the tip of the reservoir 22 when the blocking member 68 is in the closed position, or it may be configured to contact the tip of the reservoir 22 when the reservoir 22 moves toward the tip. The retaining portion 763 is not limited to a configuration that allows contact with the tip of the reservoir 22 (chemical liquid flow portion 30). For example, a protrusion may be provided on the outer circumference of the reservoir body 221, and the retaining portion 763 may be positioned toward the tip of the protrusion to allow contact.

[0077] As shown in Figure 5, in the closed position of the blocking member 68, the main body portion 761 of the blocking member 68 is positioned to cover a part of the first opening 481, and the side wall portion 762 is positioned to cover the second opening 482.

[0078] As shown in Figure 10, the biasing member 70 causes the blocking member 68 to open in a direction away from the mounting portion 20. The biasing member 70 is, for example, a torsion spring. A support pin 74 is inserted into the biasing member 70. The biasing member 70 is positioned between the internal housing 38 and the support end 681 of the blocking member 68. The biasing force of the biasing member 70 biases the blocking member 68 in a direction that causes the free end 682 of the blocking member 68 to open away from the first opening 481. That is, the biasing force of the biasing member 70 causes the blocking member 68 to open and reach the open position (see Figure 11). Note that the release prevention mechanism 66 is not limited to a configuration that includes a biasing member 70. For example, instead of the biasing force of the biasing member 70, the user may grip the blocking member 68 to cause it to open.

[0079] The locking mechanism 72 prevents the release prevention mechanism 66 from opening due to the biasing member 70 when the release prevention mechanism 66 is in the closed position. The locking mechanism 72 also prevents the release prevention mechanism 66 from moving relative to the internal housing 38 when the release prevention mechanism 66 is in the closed position. The locking mechanism 72 comprises a locking pin 721, a locking hole 722, a locking biasing member 723, and a release mechanism 724.

[0080] The lock pin 721 is movably mounted on the blocking member 68. The lock pin 721 is mounted so as to protrude outward from the free end 682 of the blocking member 68. The lock pin 721 is positioned along the width direction of the internal housing 38 (see Figure 4). The extending direction of the lock pin 721 is the same as the extending direction of the blocking member 68. The lock pin 721 is positioned inside the mounting portion 20 so as to be inside the blocking member 68 (on the cartridge 16 side). The lock pin 721 comprises a support end 781, an insertion end 782, and a pin intermediate portion 783. The support end 781 is positioned on the support portion 683 side of the blocking member 68. The insertion end 782 is positioned on the opposite side from the support end 781 in the extending direction of the lock pin 721. The insertion end 782 is inserted into the lock hole 722 of the internal housing 38 in the closed position. The insertion end 782 has an inclined portion. With the insertion end 782 inserted into the lock hole 722, the inclined portion is inclined upward from the lower surface of the insertion end 782 toward the outside of the lock hole 722.

[0081] The locking hole 722 is provided in the side wall of the internal housing 38. The locking pin 721 is inserted into the locking hole 722 when it is in the closed position. When it is in the closed position, the locking pin 721 and the locking hole 722 are arranged in a straight line in the width direction. The locking hole 722 of the internal housing 38 is covered. That is, the locking hole 722 is not exposed to the outside of the drug dispensing device 10.

[0082] The intermediate pin portion 783 is positioned between the support end 781 and the insertion end 782. The intermediate pin portion 783 has a link hole 80. The link hole 80 penetrates in a direction intersecting the extending direction of the lock pin 721. The link hole 80 extends in a vertical direction intersecting the extending direction of the lock pin 721 and is formed to be inclined upward toward the support end 781.

[0083] The locking biasing member 723 biases the lock pin 721 toward the lock hole 722. The locking biasing member 723 is, for example, a coil spring. The locking biasing member 723 is positioned between the blocking member 68 and the support end 781 of the lock pin 721. The locking biasing member 723 biases the lock pin 721 toward the widthwise outward direction of the internal housing 38 (towards the lock hole 722).

[0084] The release mechanism 724 can release the locked state of the detachment prevention mechanism 66 relative to the internal housing 38. The release mechanism 724 comprises a release operating member 821 and a link mechanism 822.

[0085] The release operation member 821 can be operated by the user when releasing the locked state of the release prevention mechanism 66. The release operation member 821 is provided so as to be movable relative to the prevention member 68. A part of the release operation member 821 is provided so as to be exposed on the outer surface of the main body 761.

[0086] In the locked state of the release prevention mechanism 66 by the locking mechanism 72, the release operation member 821 is in the locked position located on the free end 682 side along the extending direction of the prevention member 68.

[0087] The release operation member 821 comprises a rotatable support portion 841 and a release operation portion 842. The rotatable support portion 841 has a rotating shaft 86 that extends in a direction intersecting the extending direction of the blocking member 68. The rotatable support portion 841 is rotatably supported on the side wall portion 762 (see Figure 9) of the blocking member 68 via the rotating shaft 86. The rotatable support portion 841 rotatably supports the release operation member 821 about the rotating shaft 86. Note that the release operation member 821 is not limited to a configuration that allows rotation via the rotating shaft 86. For example, the release operation member 821 may be configured to slide along the extending direction of the blocking member 68.

[0088] The release operation unit 842 is exposed to the outside of the main body 761 of the blocking member 68 and is provided so that it can be released by the user. The release operation unit 842 is located on the opposite side of the rotation support unit 841 in a direction that intersects with the axis of the rotation shaft 86 of the rotation support unit 841 and also intersects with the direction of movement of the lock pin 721. The release operation unit 842 may be provided with a mark indicating the direction of operation.

[0089] The link mechanism 822 connects the release operating member 821 and the lock pin 721, and interlocks the lock pin 721 with the operation of the release operating member 821. The first end 881 of the link mechanism 822 is supported by the rotation support portion 841. The second end 882 is supported by the pin intermediate portion 783 via the link pin 883. The link pin 883 is inserted into the link hole 80 of the second end 882 and the pin intermediate portion 783. Note that the release operating member 821 is not limited to a configuration that allows rotation via the rotation shaft 86 and the link mechanism 822. For example, the release operating member 821 may be configured to move linearly along the extending direction of the blocking member 68 when releasing the locked state by the lock mechanism 72.

[0090] As shown in Figure 6, the drug dispensing device 10 further includes a contact portion 90.

[0091] As shown in Figure 12, the contact portion 90 refers to the portion where the plunger pressing portion 403 and the plunger 24 come into contact with each other when the drive mechanism 40 moves toward the plunger 24. The contact portion 90 comprises a first contact portion 921 and a second contact portion 922. The first contact portion 921 and the second contact portion 922 come into contact with each other.

[0092] As shown in Figure 6, the first contact portions 921 are provided at the base ends of each of the pair of plunger rods 242. Each of the pair of first contact portions 921 protrudes toward the base end (axial direction). In a cross-section along the direction of separation of the pair of plunger rods 242, each first contact portion 921 is tapered toward the base end.

[0093] The second contact portion 922 is provided at the tip of the plunger pressing portion 403. The second contact portion 922 is recessed from the tip of the plunger pressing portion 403 toward the base end (axial direction). In a cross-section along the separation direction of the pair of plunger rods 242, each second contact portion 922 is formed in a tapered shape toward the base end. The first contact portion 921 is inserted into the second contact portion 922 and engages with it (see Figure 12). Note that this is not limited to the case where the first contact portion 921 is provided on the plunger rod 242 and the second contact portion 922 is provided on the plunger pressing portion 403. For example, the first contact portion 921 may be provided on the plunger pressing portion 403 and protrude toward the tip, and the second contact portion 922 may be provided on the plunger rod 242 and formed recessed toward the tip. When the drive mechanism 40 moves toward the plunger 24, the plunger pressing part 403 and the plunger 24 come into contact with each other. When the drive mechanism 40 is driven in the direction of discharging the drug solution M, the plunger pressing part 403 presses against the plunger 24, and the drug solution M is delivered from the reservoir 22. After the administration of the drug solution M is complete, the cartridge 16 can be removed from the drive unit 18 by pulling only the plunger pressing part 403 back to its initial position.

[0094] The drug dispensing device 10 is not limited to a configuration that includes a contact portion 90. For example, the tip of the plunger pressing portion 403 and the base end of the plunger rod 242 may be engaged (for example, by friction engagement).

[0095] As shown in Figure 13, the holder 14 is fixed to the skin S (target area) of the living body B. The holder 14 has an adhesive sheet 141 that is fixed to the skin S of the living body B. When using the drug administration device 10, the pump unit 12 is attached to the holder 14 fixed to the skin S.

[0096] The drug administration device 10 further includes a cannula unit 94.

[0097] The cannula unit 94 is housed in the cannula unit housing section 50 of the cartridge 16. The cannula unit 94 comprises a unit body section 941 and a cannula 942 supported by the unit body section 941. The unit body section 941 has a connecting section 96 to which the base end of the flow path forming member 26 is connected. The inside of the connecting section 96 is connected to the flow path 261 of the flow path forming member 26. The tip of the cannula 942 protrudes beyond the adhesive sheet 141 of the holder 14 and is inserted into the living body B together with a puncture needle (not shown). The base end of the cannula 942 communicates with the inside of the connecting section 96 inside the internal housing 38.

[0098] The drug administration device 10 is used as follows.

[0099] First, the cartridge 16 is mounted on the drive unit 18. The following describes the initial state before the cartridge 16 is used, where the detachment prevention mechanism 66 is in the closed position and the stopping member 68 is locked by the locking mechanism 72.

[0100] The user releases the lock state of the detachment prevention mechanism 66 using the release operation member 821 while the outer wall portion 382 of the internal housing 38 of the drive unit 18 is facing upward. Specifically, from the locked state shown in Figure 10, the user moves the release operation portion 842, which is in the locked position, toward the support end 681 side of the prevention member 68. As a result, as shown in Figure 14, the release operation member 821 rotates inward in the width direction (towards the support end 681 side) with the rotation support portion 841 as the pivot point. Along with the rotation of the release operation member 821, the lock pin 721 moves in a direction in which the insertion end portion 782 detaches from the lock hole 722. The lock is released when the insertion end portion 782 of the lock pin 721 detaches from the lock hole 722. At this time, the link mechanism 822 rotates the release operation portion 842 of the release operation member 821 toward the mounting portion 20.

[0101] When the insertion end 782 of the lock pin 721 disengages from the lock hole 722, the lock state of the retaining member 68 of the release retaining mechanism 66 is released. As shown in Figure 11, the retaining member 68 rotates with its support end 681 as a pivot point, due to the biasing force of the biasing member 70, so that the free end 682 of the retaining member 68 moves away from the mounting portion 20 of the internal housing 38. As a result, as shown in Figure 15, the retaining member 68 moves away from the opening 381 and the mounting portion 20, and the release retaining mechanism 66 opens relative to the internal housing 38. Therefore, the first opening 481 and the second opening 482 are opened, and the cartridge 16 can be installed.

[0102] At this time, by operating the release operation member 821 to release the locked state of the lock mechanism 72, the blocking member 68 opens due to the biasing force of the biasing member 70.

[0103] Next, the cartridge 16 is attached to the mounting portion 20 of the drive unit 18. Specifically, as shown in Figure 16, the cartridge 16 is inserted into the mounting portion 20 from above through the opening 381. The reservoir 22 is housed in the reservoir mounting portion 201, and the flow path forming member 26 is housed in the flow path member mounting portion 202. The base end of the flow path forming member 26 is positioned in the cannula unit housing portion 50. This houses the cartridge 16 in the mounting portion 20 of the drive unit 18. At this time, the protruding portion 361 of the reservoir 22 is positioned on the opening 381 side (above). The sealing member 34 of the reservoir 22 abuts against the inner surface of the fitting portion 203 of the mounting portion 20. A liquid-tight seal is maintained between the base end of the reservoir 22 and the inner housing 38.

[0104] As shown in Figure 3, with the cartridge 16 housed in the mounting portion 20 of the drive unit 18, the detachment prevention mechanism 66 closes a portion of the opening 381. Specifically, the user grasps the free end 682 of the preventing member 68 of the detachment prevention mechanism 66, which is in the open position, and rotates it so that the free end 682 faces the internal housing 38, using the support portion 683 as a pivot point. The preventing member 68 is then rotated to the closed position until its main body portion 761 is aligned with the outer wall portion 382 of the internal housing 38. In the closed position, a portion of the opening 381 of the internal housing 38 is covered by the preventing member 68. More specifically, a portion of the first opening 481 is covered by the main body portion 761 of the preventing member 68, and the second opening 482 is covered by the side wall portion 762 (see Figure 9).

[0105] As the release prevention mechanism 66 rotates toward the closed position, the insertion end 782 of the lock pin 721 contacts the side wall 762 of the internal housing 38. This contact with the side wall 762 compresses the lock biasing member 723, causing the lock pin 721 to move over the side wall 762. After the insertion end 782 moves over the side wall 762, in the closed position the insertion end 782 faces the lock hole 722, causing the lock biasing member 723 to move the lock pin 721 toward the lock hole 722. The biasing force of the lock biasing member 723 causes the insertion end 782 of the lock pin 721 to be inserted into the lock hole 722. As a result, in the closed position of the release prevention mechanism 66, the opening operation of the release prevention mechanism 66 is prevented, resulting in a locked state (see Figure 10). The release prevention mechanism 66 prevents the cartridge 16 mounted on the mounting portion 20 from detaching from the internal housing 38. The retaining portion 763 of the detachment prevention mechanism 66 is positioned to face the liquid flow portion 30 of the reservoir 22 (see Figure 12).

[0106] This completes the mounting of the cartridge 16 to the mounting portion 20 of the drive unit 18. When the drive unit 18 and the cartridge 16 are assembled together, the power supply unit D provided on the circuit board K is turned on. When the power supply unit D is turned on, power can be supplied from the power supply unit 42 to the drive unit 401. As shown in Figure 4, in the initial state after the drive unit 18 and the cartridge 16 are assembled together and before the drive mechanism 40 is driven, the plunger 24 of the cartridge 16 and the plunger pressing portion 403 of the drive unit 18 are spaced apart in the axial direction.

[0107] Next, the reservoir 22 is filled with the drug solution M. Specifically, a drug delivery device (not shown), such as a syringe filled with the drug solution M, is prepared, and the drug solution M is filled into the drug chamber 28 of the reservoir 22 through a port (not shown) in the cannula unit housing section 50.

[0108] As shown in Figure 7, when the drug chamber 28 is filled with the drug solution M, the plunger 24 is pushed and moved toward the base end by the drug solution M. The plunger rod 242 protrudes toward the base end beyond the reservoir 22 through the guide hole 32 of the guide portion 223. Inside the internal housing 38, the plunger rod 242 moves toward the plunger pressing portion 403, and the first contact portion 921 of the plunger rod 242 is inserted into the second contact portion 922 of the plunger pressing portion 403. After the filling of the reservoir 22 with the drug solution M is complete, the drug solution delivery device (not shown) is removed from the cartridge 16.

[0109] Next, with the holder 14 pre-fixed to the skin S of a predetermined site on the living body B via the adhesive sheet 141, the puncture needle of a puncture device (not shown) and the cannula 942 are inserted into the skin S of the living body B. With the cannula 942 placed subcutaneously, the puncture device (not shown) is removed, leaving only the cannula 942 subcutaneously. The unit body 941 of the cannula unit 94 is fixed to the holder 14 by the puncture device (not shown) when the cannula 942 is placed.

[0110] Next, the pump unit 12 is attached to the holder 14. Specifically, as shown in Figure 13, the internal housing 38 of the drive unit 18 is brought into contact with the holder 14. The unit body 941 of the cannula unit 94 is housed in the cannula unit housing 50. When the user slides the pump unit 12 toward the base end with the lower surface of the pump unit 12 in contact with the upper surface of the holder 14, the base end of the flow path forming member 26 and the unit body 941 are connected, and the flow passage 261 and the cannula 942 communicate with each other.

[0111] Next, the holder detection unit SB detects that the connection to the holder 14 is complete, making it ready for administration. In response to an instruction from a handset (not shown), the drive shaft 541 of the drive unit 401 rotates, causing the shaft 402 to rotate in a predetermined direction via the gear mechanism 56. As shown in Figure 12, as the shaft 402 rotates, the plunger pressing unit 403 moves toward the tip, pushing the plunger rod 242 toward the tip.

[0112] As the plunger 24 moves toward the tip, the plunger body 241 pushes the drug solution M out of the drug chamber 28 and flows from the drug solution distribution section 30 into the flow passage 261. As shown in Figure 13, the drug solution M in the flow passage 261 is administered subcutaneously to the living organism B through the cannula 942 via the unit body 941 of the cannula unit 94 from the base end of the flow path forming member 26. At this time, as shown in Figure 12, the plunger rod 242 is supported by the guide hole 32, and the plunger 24 moves toward the tip.

[0113] When the plunger body 241 reaches the tip of the drug chamber 28 due to the plunger pressing part 403, the drug solution M in the drug chamber 28 is administered to the patient, completing the administration. At this time, the plunger rod 242 of the plunger 24 is housed inside the reservoir body 221 through the guide hole 32 of the guide part 223, and the tip of the plunger pressing part 403 is inserted into the guide hole 32 (see the dashed line shape in Figure 12). In this way, the plunger pressing part 403 can compensate for the length of the plunger 24 on the cartridge 16 side. As a result, the axial length of the cartridge 16 and the drug solution administration device 10 can be shortened, and the drug solution administration device 10 can be made smaller.

[0114] The pump unit 12 is detachable from the holder 14. For example, when a patient takes a bath, the delivery (administration) of the drug solution M can be stopped using the handset, the pump unit 12 can be removed from the holder 14, and then reconnected after bathing to resume the administration of the drug solution M.

[0115] After the drug administration device 10 has finished administering the drug solution M to the living organism B, the pump unit 12 is removed from the holder 14. The cartridge 16 is removed from the drive unit 18 of the pump unit 12, and the used cartridge 16 is discarded. When removing the cartridge 16 from the drive unit 18, the user releases the lock state of the detachment prevention mechanism 66, rotates the stopping member 68 to open the opening 381, and then removes it. The operation of the detachment prevention mechanism 66 is the same as when the cartridge 16 is attached to the drive unit 18, so a detailed explanation is omitted. After the cartridge 16 is removed, the drive unit 18 is reusable.

[0116] As shown in Figure 16, the blocking member 68 of the detachment prevention mechanism 66 is rotated to open the opening 381, and the user pushes the protruding portion 361 of the reservoir 22 toward the tip of the internal housing 38. As a result, the cartridge 16 including the reservoir 22 moves toward the tip and is pushed out of the mounting portion 20 to the outside. Alternatively, the user may grasp the base end of the tab member 362 and pull it toward the direction away from the internal housing 38, thereby pulling the reservoir 22 out of the mounting portion 20 through the opening 381 to the outside.

[0117] The first embodiment provides the following effects.

[0118] As shown in Figure 4, the drug dispensing device 10 comprises a cartridge 16 having a reservoir 22 and a plunger 24, and a drive unit 18 having a drive mechanism 40 to which the cartridge 16 can be attached and detached. The drive unit 18 includes a detachment prevention mechanism 66 that is openable and closable and provided in the internal housing 38 in which the cartridge 16 is mounted. As shown in Figure 16, the detachment prevention mechanism 66 allows the cartridge 16 to detach from the mounting portion 20 in the open position, and as shown in Figure 3, prevents the cartridge 16 from detaching from the internal housing 38 in the closed position.

[0119] With this configuration, when attaching or detaching the cartridge 16 to the drive unit 18, the detachment prevention mechanism 66 can be opened and closed to easily remove and install the cartridge 16.

[0120] The detachment prevention mechanism 66 includes a preventing member 68 that is rotatably supported by the internal housing 38.

[0121] With this configuration, the mounting portion 20 can be effectively opened and closed by rotating the blocking member 68 relative to the internal housing 38. By rotating the blocking member 68 relative to the internal housing 38, the width of the drug dispensing device 10 does not need to be increased even if the blocking member 68 is provided.

[0122] As shown in Figure 9, the blocking member 68 covers only a portion of the cartridge 16 from the direction of detachment of the cartridge 16.

[0123] With this configuration, when the cartridge 16 is attached to the drive unit 18, the liquid medicine M inside the cartridge 16 can be easily seen, thereby increasing safety during use.

[0124] As shown in Figure 9, the detachment prevention mechanism 66 includes a biasing member 70 that causes the preventing member 68 to move in a direction away from the mounting portion 20.

[0125] With this configuration, when removing the cartridge 16 from the drive unit 18, the biasing force of the biasing member 70 makes it easy to open the blocking member 68.

[0126] As shown in Figure 5, the blocking member 68 faces the reservoir 22 in the axial direction when in the closed position and has a holding portion 763 to which a part of the reservoir 22 can come into contact.

[0127] With this configuration, when the reservoir 22 is filled with the drug solution M, the movement of the reservoir 22 toward the tip can be effectively suppressed.

[0128] As shown in Figure 10, the device includes a locking mechanism 72 that prevents the release prevention mechanism 66 from opening when it is in the closed position.

[0129] This configuration effectively prevents the detachment prevention mechanism 66 from accidentally opening when the cartridge 16 is installed, even when it is in the closed position.

[0130] The blocking member 68 has a cantilever structure comprising a support end 681 having a support portion 683 supported by the internal housing 38, and a free end 682 provided at the end opposite to the support end 681. The locking mechanism 72 comprises a lock pin 721 movably provided on the blocking member 68, a lock hole 722 into which the lock pin 721 is inserted in the closed position, and a locking biasing member 723 that biases the lock pin 721 toward the lock hole 722.

[0131] With this configuration, the locked state of the blocking member 68 can be effectively maintained by the biasing force of the locking biasing member 723 when the blocking member 68 is in the closed position.

[0132] The locking mechanism 72 has a release mechanism 724 that can release the locked state of the release prevention mechanism 66. When the prevention member 68 is locked by the locking mechanism 72, the release operation member 821 is in the locked position, and by moving the release operation member 821 toward the support end 681, the lock pin 721 moves in a direction that separates it from the lock hole 722 via the link mechanism 822, and it becomes the unlocked position.

[0133] With this configuration, the locking mechanism 72 can effectively release the lock state of the release prevention mechanism 66 by operating the release operation member 821.

[0134] The release operation member 821 comprises a pivot support portion 841 that is rotatably supported by the blocking member 68, and a release operation portion 842 that is located on the opposite side of the pivot support portion 841 and can be released by the user. In the locked position, the release operation portion 842 is positioned along the extending direction of the blocking member 68. By moving the release operation member 821 toward the support end 681, the release operation member 821 rotates around the pivot support portion 841 as a pivot point to reach the unlocked position.

[0135] With this configuration, when the lock state is released by the release mechanism 724, the release operation part 842 is moved toward the support part 683, which is the center of the opening operation of the blocking member 68, thereby releasing the lock. The user can easily understand the lock release operation intuitively.

[0136] As shown in Figure 3, the cartridge 16 is equipped with an extraction assist structure 36 for moving the cartridge 16 away from the extraction section 20 when the cartridge 16 is extracted from the extraction section 20. The extraction assist structure 36 is provided on the outer circumference of the reservoir 22 and includes a protruding portion 361 that protrudes from the outer circumference.

[0137] With this configuration, when removing the cartridge 16 from the mounting section 20 of the drive unit 18, the user can push the protruding portion 361 in the direction of removal of the cartridge 16, thereby moving the cartridge 16 within the mounting section 20 and making it easier to remove from the mounting section 20.

[0138] As shown in Figure 5, the protruding portion 361 extends beyond one surface of the outer wall portion 382 of the inner housing 38, protruding in a direction that causes the cartridge 16 to detach from the drive unit 18.

[0139] With this configuration, it is easier for the user to operate the cartridge 16 by pressing the protruding part 361 when removing it.

[0140] As shown in Figure 3, the outer wall portion 382 of the inner housing 38 has an opening 381 that communicates with the mounting portion 20, and in the closed position, the blocking member 68 is positioned so as to intersect with the opening direction of the opening 381.

[0141] This configuration allows for effective attachment and detachment of the cartridge 16 to and from the mounting portion 20 through the opening 381.

[0142] As shown in Figure 3, the locking mechanism 72 is movably mounted and exposed on the outer surface of the blocking member 68, and has a release operating member 821 that can release the locked state of the release blocking mechanism 66. As shown in Figure 13, the release operating member 821 cannot be seen from the outside when the drive unit 18 is mounted on the holder 14.

[0143] With this configuration, since the release operation member 821 is covered by the living organism B and the holder 14, it is possible to effectively prevent the user from accidentally operating the release operation member 821 when attaching the drug administration device 10 to the body surface (skin S) of the living organism B.

[0144] The drive unit 18 includes an internal housing 38 having a mounting portion 20 on which the cartridge 16 is mounted, and a detachment prevention mechanism 66 provided in the internal housing 38 so as to be openable and closable. The detachment prevention mechanism 66 allows the cartridge 16 to detach from the mounting portion 20 when in the open position, and prevents the cartridge 16 from detaching from the internal housing 38 when in the closed position.

[0145] With this configuration, when attaching or detaching the cartridge 16 to the drive unit 18, the detachment prevention mechanism 66 can be opened and closed to easily remove and install the cartridge 16.

[0146] As shown in Figure 17, the drug dispensing device 10A according to the second embodiment includes a pump unit 12A. The pump unit 12A is detachably mounted to a holder (not shown). Note that components identical to those of the drug dispensing device 10A according to the first embodiment are given the same reference numerals, and detailed descriptions are omitted.

[0147] The pump unit 12A includes a cartridge 16A. As shown in Figure 18, the cartridge 16A is detachably mounted on the mounting portion 20 of the drive unit 18A. The cartridge 16A includes a reservoir 22A and a flow path forming portion 26A.

[0148] As shown in Figure 19, the reservoir 22A comprises a reservoir body 221A, a pressure-receiving portion 23A, and a flow path forming portion 26A. The reservoir body 221A is formed in the shape of a syringe barrel and has a chamber 28 inside into which the drug solution M is introduced (see Figure 21). As shown in Figure 20, when viewed from the axial direction of the reservoir 22A, the cross-section of the reservoir body 221A is circular. However, the cross-section of the reservoir body 221A is not limited to a circular shape. For example, the cross-section of the reservoir body 221A may be elliptical or oblong.

[0149] As shown in Figure 21, the reservoir body 221A is provided with a tip wall portion 100. The tip wall portion 100 is located at the tip of the reservoir body 221A and closes the tip. The tip wall portion 100 faces the tip of the chamber 28. The tip wall portion 100 covers the tip of the chamber 28 in the axial direction. The tip wall portion 100 is formed in a tapered shape that decreases in diameter towards the tip of the reservoir body 221A.

[0150] As shown in Figure 24, the tip wall portion 100 is provided with a reservoir port 102. The reservoir port 102 is used as an outlet port when discharging the drug solution M from the reservoir 22A (drug chamber 28) to the outside, and is also used as an introduction port when introducing the drug solution M into the drug chamber 28 from outside the reservoir 22A. The reservoir port 102 is formed on the outer edge of the drug chamber 28 in the radial direction of the reservoir body 221A.

[0151] The reservoir port 102 penetrates the tip wall 100 in the axial direction of the reservoir body 221A. The reservoir port 102 extends to the outer surface of the tip wall 100 and opens into the chamber 28. The reservoir port 102 communicates with the chamber 28. The reservoir port 102 extends from the chamber 28 toward the tip.

[0152] As shown in Figure 23, the pressed portion 23A is pressed toward the base end by the pressing portion (holding portion) 692 of the drive unit 18A, which will be described later, when the cartridge 16A is attached to the drive unit 18A. The pressed portion 23A is provided on the outer surface (tip surface) of the tip wall portion 100 of the reservoir body 221A (see Figure 19). That is, the pressed portion 23A is a flat plate-shaped portion provided at the tip of the reservoir body 221A. The pressed portion 23A extends along a direction perpendicular to the axial direction of the reservoir body 221A. The pressed portion 23A extends along the radial direction of the reservoir body 221A. Specifically, when the reservoir 22A is viewed from the axial direction, the pressed portion 23A is arranged along the horizontal direction perpendicular to the axial direction of the reservoir body 221A (see Figure 20). The pressed portion 23A protrudes from the tip wall portion 100 toward the tip.

[0153] The plane formed at the tip of the pressed portion 23A (flat plate portion) (the contact surface 230 described later) extends along a direction perpendicular to the axial direction of the reservoir body 221A. Preferably, when viewed from the axial direction of the reservoir 22A, the plane formed at the tip of the pressed portion 23A (flat plate portion) (the contact surface 230 described later) is positioned to one side from the center of the reservoir body 221A. Here, the one side is the lower side when the cartridge 16A is attached to the drive unit 18A.

[0154] As shown in Figure 20, when viewed from the axial direction of the reservoir 22A, the pressed portion 23A is provided on one side of a first imaginary line L1 that passes through the axis of the reservoir body 221A and extends horizontally. The side of the first imaginary line L1 is the side on which the flow path forming portion 26A is provided.

[0155] As shown in Figure 19, the pressed portion 23A has a first contact portion 231 and a second contact portion 232. The first contact portion 231 and the second contact portion 232 have the same shape. As shown in Figure 20, when the reservoir 22A is viewed from the axial direction, the first contact portion 231 and the second contact portion 232 are spaced apart from each other in the horizontal direction (direction perpendicular to the axial direction) of the reservoir body 221A. The first contact portion 231 and the second contact portion 232 are spaced apart from each other with respect to the axis of the reservoir body 221A. The second contact portion 232 is provided between the first contact portion 231 and the flow path forming portion 26A.

[0156] Viewed from the axial direction of the reservoir 22A, the first contact portion 231 and the second contact portion 232 are provided on both sides of the second virtual line L2, which passes through the axis of the reservoir body 221A and is perpendicular to the first virtual line L1. In other words, the pressed portion 23A is positioned to straddle the second virtual line L2.

[0157] The first contact portion 231 and the second contact portion 232 each have a contact surface 230. Each contact surface 230 is formed at the tip of the first contact portion 231 and the second contact portion 232, respectively (see Figure 23). Each contact surface 230 is a plane perpendicular to the axis of the reservoir body 221A. In the axial direction of the reservoir body 221A, the contact surface 230 of the first contact portion 231 and the contact surface 230 of the second contact portion 232 are at the same position. When viewed from a direction perpendicular to the axial direction of the reservoir body 221A, the first contact portion 231 (contact surface 230) and the second contact portion 232 (contact surface 230) and the base end of the flow path forming portion 26A are at the same position (height) in the axial direction of the reservoir body 221A.

[0158] The pressed portion 23A is not limited to a configuration comprising a first contact portion 231 and a second contact portion 232. For example, the pressed portion 23A may have a configuration comprising one contact portion. In this case, the pressed portion 23A may have a configuration in which the first contact portion 231 and the second contact portion 232 are connected. Furthermore, the pressed portion 23A may have a configuration comprising three or more contact portions.

[0159] As shown in Figure 23, when the cartridge 16A is attached to the drive unit 18A, the contact surfaces 230 of the first contact portion 231 and the second contact portion 232 are provided to be able to contact the pressing portion 692 of the drive unit 18A, which will be described later. Specifically, the contact surfaces 230 of the first contact portion 231 and the second contact portion 232 and the pressing portion 692 of the drive unit 18A, which will be described later, are in surface contact. Note that the configuration is not limited to surface contact between the pressed portion 23A and the pressing portion 692. It is sufficient if the pressed portion 23A and the pressing portion 692 are in contact and the pressed portion 23A can be pressed in the base end direction by the pressing portion 692.

[0160] As shown in Figure 19, the flow path forming section 26A is located on the outer circumference of the reservoir body 221A. As shown in Figure 22, the flow path forming section 26A has a flow passage 261 through which the chemical solution M can flow. When viewed from a direction perpendicular to the axial direction of the reservoir 22A, the flow path forming section 26A is formed in a substantially L-shape.

[0161] The flow path forming section 26A comprises a flow path base 311 and a flow path forming member 312.

[0162] The flow path base 311 is supported by the reservoir body 221A. As shown in Figure 22, the flow path base 311 is provided on the outer surface of the reservoir body 221A and extends along the outer surface of the reservoir body 221A. The flow path base 311 is provided parallel to the axial direction of the reservoir body 221A. The flow path base 311 is supported by the outer surface of the reservoir body 221A.

[0163] As shown in Figure 17, the drive unit 18A is further equipped with a detachment prevention mechanism 66A.

[0164] The detachment prevention mechanism 66A is provided so as to be openable and closable with respect to the outer wall portion 382 of the inner housing 38 (see Figure 18). As shown in Figure 22, the detachment prevention mechanism 66A is provided at the tip of the inner housing 38. The detachment prevention mechanism 66A is provided so as to be switchable between an open position and a closed position by opening and closing it.

[0165] In the closed position of the detachment prevention mechanism 66A, the detachment prevention mechanism 66A prevents the cartridge 16A mounted on the mounting portion 20 from detaching from the internal housing 38. In the closed position, the detachment prevention mechanism 66A closes a portion of the opening 381 of the internal housing 38. On the other hand, in the open position of the detachment prevention mechanism 66A, the detachment prevention mechanism 66A allows the cartridge 16A to detach from the mounting portion 20 (see Figure 18).

[0166] As shown in Figure 21, the detachment prevention mechanism 66A comprises a prevention member 68A, a plate member 106, and a cover member 108. The prevention member 68A extends in the width direction of the internal housing 38. As shown in Figure 17, the width direction of the internal housing 38 intersects with the axial direction of the plunger 24 and intersects with the thickness direction of the internal housing 38.

[0167] The blocking member 68A has a main body portion 691 and a pressing portion 692. The main body portion 691 extends from the support end 681A to the free end 682A. The main body portion 691 is formed along the outer wall portion 382 of the inner housing 38.

[0168] As shown in Figure 21, the pressing portion 692 is perpendicular to the extending direction and width direction of the main body portion 691. The pressing portion 692 has a flat pressing surface 693. The pressing portion 692 is provided inside the internal housing 38 when the blocking member 68A is in the closed position. When the blocking member 68A is in the closed position, the pressing surface 693 of the pressing portion 692 faces the pressed portion 23A of the reservoir 22A in the axial direction. When the blocking member 68A is in the closed position, the pressed portion 23A of the reservoir 22A and the pressing surface 693 of the pressing portion 692 come into contact.

[0169] Specifically, as shown in Figure 23, the contact surfaces 230 of the first contact portion 231 and the second contact portion 232 of the pressed portion 23A make surface contact with the pressing surface 693 of the pressing portion 692. The pressing portion 692 is formed to a length that allows the first contact portion 231 and the second contact portion 232 to make contact. Note that the pressed portion 23A of the reservoir 22A and the pressing surface 693 of the pressing portion 692 do not necessarily have to make surface contact. The pressed portion 23A of the reservoir 22A is pressed toward the base end by the pair of pressing portions 692.

[0170] As shown in Figure 21, the end of the pressing portion 692 has a rib portion 694. The rib portion 694 is inclined toward the tip relative to the pressing portion 692. That is, the rib portion 694 is inclined toward the direction away from the pressed portion 23A of the reservoir 22A.

[0171] The plate member 106 is formed from a metal plate. The plate member 106 is provided in the direction of the tip of the main body portion 691 of the blocking member 68A and is fixed to the main body portion 691. The plate member 106 is provided along the main body portion 691 and abuts against the main body portion 691. Note that the plate member 106 is not limited to being formed from a metal material.

[0172] The cover member 108 is provided in the direction of the tip of the plate member 106. As shown in Figure 24, the cover member 108 is fixed to the main body 691 of the blocking member 68A together with the plate member 106 via the fastening member 110. As shown in Figure 25, the rotation shaft 86 of the release operation member 821 is supported by the main body 691 of the blocking member 68A, the plate member 106, and the cover member 108.

[0173] Next, the case of attaching the cartridge 16A to the drive unit 18A will be described. Starting from the initial state before the cartridge 16A is used, the locking mechanism 72 releases the lock of the blocking member 68A, and then the cartridge 16A is inserted into the mounting portion 20 of the drive unit 18A. The reservoir 22A is housed in the reservoir mounting portion 201, and the flow path forming member 312 is housed in the flow path member mounting portion 202.

[0174] The user rotates the release prevention mechanism 66A, which is in the open position, so that the free end 682A of the stopping member 68A faces the internal housing 38. As shown in Figure 26, as the release prevention mechanism 66A rotates toward the closed position, the rib portion 694 of the stopping member 68A comes into contact with the pressed portion 23A. By further rotating the stopping member 68A toward the closed position, the pressed portion 23A is pushed toward the base end by the rib portion 694 and moves.

[0175] The reservoir body 221A is pushed by the rib portion 694, causing the reservoir body 221A to move to a predetermined position on the reservoir mounting portion 201. Then, the blocking member 68A is rotated until its main body portion 691 is aligned with the outer wall portion 382 of the inner housing 38, thereby closing it (see Figure 25).

[0176] When the blocking member 68A is in the closed position, a portion of the opening 381 of the internal housing 38 is covered by the blocking member 68A. The pressing portion 692 of the release blocking mechanism 66A faces the pressed portion 23A of the reservoir 22A and presses the pressed portion 23A toward the base end.

[0177] Specifically, the pressing portion 692 makes surface contact with the contact surfaces 230 of the first contact portion 231 and the second contact portion 232, thereby pushing the pressed portion 23A toward the base end. The pressing portion 692 of the blocking member 68A restricts the movement of the reservoir 22A toward the tip end and holds it in place (see Figure 23). At this time, a load is applied from the pressing portion 692 toward the base end to the pressed portion 23A, but the load is absorbed only by the pressed portion 23A, thereby suppressing the application of load to the reservoir body 221A.

[0178] This completes the mounting of the cartridge 16A to the mounting section 20 of the drive unit 18A.

[0179] The second embodiment provides the following effects.

[0180] As shown in Figure 18, in the drug dispensing device 10A, the tip end of the mounting portion 20 (storage portion 383) is covered by the wall surface of the outer housing 44. With this configuration, the cartridge 16A is prevented from being pushed toward the base end from outside the outer housing 44, and thus the excessive discharge of the drug solution M caused by the cartridge 16A being pushed toward the base end can be effectively suppressed.

[0181] 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 intent 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 dispensing device comprising: a cartridge having a reservoir capable of containing a drug solution and a plunger provided to be movable in the axial direction of the reservoir for discharging the drug solution from the reservoir; and a drive unit having a drive mechanism for driving the plunger in the axial direction, the cartridge being detachable, wherein the drive unit comprises an internal housing having a mounting portion into which the cartridge is mounted, and a detachment prevention mechanism provided in the internal housing so as to be openable and closable, which allows the cartridge to detach from the mounting portion in the open position and prevents the cartridge mounted on the mounting portion from detaching from the internal housing in the closed position.

2. A drug dispensing device according to claim 1, wherein the detachment prevention mechanism comprises a prevention member rotatably supported in the internal housing.

3. A drug dispensing device according to claim 2, wherein the blocking member covers only a portion of the cartridge from the direction of detachment of the cartridge.

4. A drug dispensing device according to claim 3, wherein the detachment prevention mechanism comprises a biasing member that causes the preventing member to move in a direction away from the mounting portion.

5. A drug dispensing device according to claim 3 or 4, wherein the blocking member has a holding portion that faces the reservoir in the axial direction in the closed position and into contact with a part of the reservoir.

6. A drug dispensing device according to claim 3 or 4, comprising a locking mechanism that prevents the opening operation of the detachment prevention mechanism when the detachment prevention mechanism is in the closed position.

7. A drug dispensing device according to claim 6, wherein the blocking member has a cantilever structure comprising: a support end having a support portion supported by the internal housing; and a free end provided at the end opposite to the support end in the extending direction of the blocking member; and the locking mechanism comprises: a lock pin movably provided on the blocking member and capable of protruding outward from the free end; a lock hole provided in the internal housing into which the lock pin is inserted in the closed position; and a locking biasing member that biases the lock pin toward the lock hole.

8. A drug dispensing device according to claim 7, wherein the locking mechanism has a release mechanism capable of releasing the locked state of the release prevention mechanism, the release mechanism comprises a release operating member provided movably on the outer surface of the prevention member and exposed to it, and a link mechanism connecting the release operating member and the lock pin, and interlocking the lock pin with the operation of the release operating member, wherein in the locked state of the prevention member by the locking mechanism, the release operating member is in a locked position moved toward the free end side along the extending direction of the prevention member, and by moving the release operating member toward the support end side in the extending direction of the prevention member, the lock pin moves toward the direction of release from the lock hole via the link mechanism, thereby becoming an unlocked position.

9. A drug dispensing device according to claim 8, wherein the release operating member comprises: a pivot support portion rotatably supported by the blocking member; and a release operating portion located on the opposite side of the pivot support portion in a direction intersecting the axis of rotation of the pivot support portion and intersecting the direction of movement of the lock pin, and exposed to the outside of the blocking member so as to be released by a user, wherein in the locked position, the release operating portion is located along the extending direction of the blocking member, and in order to move from the locked position to the unlocked position, the release operating member rotates with the pivot support portion as a fulcrum by moving the release operating member toward the support end.

10. A drug solution dispensing device according to claim 1, wherein the cartridge is provided with a removal assist structure for moving the cartridge away from the mounting portion when removing the cartridge mounted on the mounting portion, and the removal assist structure is provided on the outer periphery of the reservoir and includes a protruding portion that protrudes from the outer periphery.

11. A drug dispensing device according to claim 10, wherein the protruding portion extends beyond one surface of the outer wall of the inner housing and protrudes in a direction that causes the reservoir to detach from the drive unit.

12. A drug solution dispensing device according to claim 2, wherein the outer wall portion of the inner housing has an opening that communicates with the mounting portion, and the blocking member is positioned so as to intersect the opening direction of the opening when in the closed position.

13. A drug administration device according to claim 1, comprising a holder for holding a cannula to be inserted into a living body, a locking mechanism for preventing the opening of the detachment prevention mechanism when the detachment prevention mechanism is in the closed position, the locking mechanism is provided so as to be exposed to the outer surface of the prevention member and has a release operating member that can release the locked state of the detachment prevention mechanism, and the release operating member cannot be seen from the outside when the drive unit is mounted on the holder.

14. A drive unit for which a cartridge having a reservoir capable of containing a liquid medicine and a plunger disposed in the reservoir is detachable, comprising: a drive mechanism that biases the plunger toward the tip by moving in the axial direction of the reservoir; an internal housing having a mounting portion into which the cartridge is mounted; and a detachment prevention mechanism provided in the internal housing so as to be openable and closable, which allows the cartridge to detach from the mounting portion in the open position and prevents the cartridge mounted on the mounting portion from detaching from the internal housing in the closed position.

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