Medical solution administration device

Abstract

To provide a medical solution administration device for administering a medical solution to a body of a patient.SOLUTION: A medical solution administration device 10 includes a cylindrical body 60 supported by a reservoir holder 42, a needle cover 70 arranged to be movable in an axial direction of the cylindrical body 60 at a distal end of the cylindrical body 60, and a movement regulation mechanism 90 for regulating movements of the needle cover 70 in a proximal end direction. The movement regulation mechanism 90 includes a regulation member 92 and an elastic member 94. The regulation member 92 is movable in the axial direction of the cylindrical body 60. The elastic member 94 applies elastic force for making the regulation member 92 move in a distal end direction to the regulation member 92. The elastic force is applied to the needle cover 70 through the regulation member 92.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a medical fluid administration device for administering a medical fluid to the body of a patient. [Background technology]

[0002] A conventionally known drug solution administration device includes a reservoir that stores a drug solution and a reservoir holder that holds the reservoir. A puncture needle and a button are provided at the distal end and proximal end of the reservoir holder, respectively. When the puncture needle is inserted into the patient's body, the user presses the button with the thumb or the like, causing the drug solution in the reservoir to move to the puncture needle. The drug solution is then administered to the patient via the puncture needle.

[0003] Generally, the puncture needle is covered with a needle cap until immediately before the liquid medicine is administered to the patient. The user removes the needle cap to expose the puncture needle, and then inserts the puncture needle into the patient's body (skin). In this state, the user presses the button with the thumb or the like. After releasing the finger from the button, the user moves the liquid medicine administration device in a direction away from the patient's body. As a result of this movement, the puncture needle is removed from the patient's body.

[0004] The puncture needle is exposed from the time the needle cap is removed until puncture begins. The puncture needle is also exposed even after administration of the drug solution is completed and the needle is removed from the patient's body. Therefore, there is a concern that the exposed puncture needle may puncture a part of the patient other than the puncture part. In order to avoid such erroneous puncture, Patent Document 1 proposes a configuration in which the needle is covered with a double shield of an inner shield and an outer shield. Patent Document 2 also proposes a configuration in which the puncture needle is covered with a shield assembly and the shield assembly is covered with a cap, and the cap is removed from the shield assembly when puncturing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6426399 [Patent Document 2] Patent No. 4298511 Summary of the Invention [Problem to be solved by the invention]

[0006] For example, in a drug solution injection device for injecting insulin, a reservoir often stores an amount of insulin that allows multiple injections to a patient. In this case, a puncture needle is attached to the reservoir in a replaceable manner. A user replaces the puncture needle with a new one every time insulin is injected.

[0007] The drug solution dispensing device described in Patent Document 1 and the drug solution dispensing device described in Patent Document 2 can be used only once. That is, these drug solution dispensing devices are discarded as medical waste after administering drug solution to a patient once. For this reason, in the drug solution dispensing device described in Patent Document 1, the puncture needle is not replaceable with respect to the reservoir. In addition, since the puncture needle is covered with an inner shield after use, it is not easy to replace the puncture needle with a new one. In the drug solution dispensing device described in Patent Document 2, when the puncture needle is removed from the reservoir holder, the shield assembly is removed from the reservoir holder together with the puncture needle.

[0008] Therefore, in a drug solution administration device in which the puncture needle is replaced with a new one each time a drug solution is administered, it is not easy to prevent accidental puncture based on the double shield described in Patent Document 1 or the shield assembly described in Patent Document 2.

[0009] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0010] (1) A first aspect of the present invention is a drug solution administration device including a reservoir holder for holding a reservoir that stores a drug solution. The drug solution administration device includes a cylindrical body supported by the reservoir holder, a needle cover that is arranged at the tip of the cylindrical body so as to be movable in the axial direction of the cylindrical body and has an opening at the tip, and a movement restriction mechanism that restricts movement of the needle cover toward the base end. The reservoir has a base portion to which a puncture needle that is punctured into the body of a living organism to administer the drug solution in the reservoir to the body can be attached and detached.

[0011] The movement restriction mechanism includes a restricting member movable within the cylindrical body along the axial direction of the cylindrical body, and an elastic member that applies an elastic force to the restricting member such that the restricting member moves toward the distal end, thereby applying the elastic force to the needle cover via the restricting member. The movement restriction mechanism restricts the movement of the needle cover toward the proximal end when a force smaller than the elastic force of the elastic member acts on the needle cover. In contrast, the movement restriction mechanism allows the movement of the needle cover toward the proximal end when a force equal to or greater than the elastic force of the elastic member acts on the needle cover.

[0012] In the attachment step of attaching the puncture needle to the base portion, a force in the proximal direction is applied to the needle cover, causing the movement restriction mechanism to permit movement of the needle cover in the proximal direction and causing the elastic member to contract.

[0013] In the pre-use stage after the attachment stage, in which the force is removed from the needle cover, the needle cover moves toward the tip by being pushed by the regulating member as the elastic member stretches, so that the tip of the needle cover is positioned more tip-side than the tip of the puncture needle and the needle cover surrounds the outer periphery of the puncture needle.

[0014] During the puncture stage in which the puncture needle is inserted into the body, a force is applied to the needle cover in a base direction from the body, causing the regulating member to allow the needle cover to move in the base direction while the elastic member contracts, and the tip of the needle cover becomes positioned closer to the base end than the tip of the puncture needle, exposing the puncture needle from the opening.

[0015] During the removal stage when the puncture needle is removed from the body, the needle cover moves toward the tip by being pushed by the regulating member as the elastic member stretches, so that the tip of the needle cover is positioned further toward the tip of the puncture needle, and the needle cover surrounds the outer circumference of the puncture needle.

[0016] As can be seen from the above, the outer periphery of the puncture needle is surrounded by the needle cover during the pre-use and removal stages. This prevents the puncture needle from accidentally puncturing the body of a living body (user or patient, etc.). In other words, the needle cover can prevent accidental puncture. Moreover, when a force is applied to push the needle cover toward the proximal end, the needle cover easily moves toward the proximal end. Therefore, the needle cover does not prevent the puncture needle from puncturing the patient's body.

[0017] Furthermore, if a small force is applied to the needle cover during the removal step, the needle cover is prevented from moving in the proximal direction, thereby preventing the puncture needle from being exposed from the needle cover in an unexpected event.

[0018] (2) In the drug solution administration device described in the above item (1), the movement restriction mechanism may have a snap fit having an engagement claw as the restriction member. The engagement claw may be engaged with an engagement target to restrict the movement of the needle cover in the proximal direction, and the engagement claw may be disengaged from the engagement target to allow the movement of the needle cover in the proximal direction.

[0019] In the movement restriction mechanism including the snap fit, as described above, the engagement claw engages with the engagement object to restrict the movement of the needle cover toward the base end, and the engagement claw and the engagement object are disengaged to allow the movement of the needle cover toward the base end. Therefore, with this configuration, it is easy to switch between restricting movement of the needle cover and allowing movement.

[0020] (3) In the drug solution administration device described in the above item (2), the movement restriction mechanism may have a second cylindrical body disposed inside the cylindrical body. The engagement claw of the snap fit may engage with an engagement portion provided on the second cylindrical body in the pre-use stage and the removal stage, and may be disengaged from the engagement portion and inserted into the second cylindrical body in the attachment stage and the puncture stage.

[0021] When the tip of the snap fit is pushed from the base end of the needle cover, the engagement of the engagement claw with the engagement portion of the second cylindrical body is easily released, and the movement of the needle cover toward the base end is permitted. The engagement claw is inserted into the inside of the second cylindrical body. When an elastic force toward the tip end is applied to the needle cover from the elastic member, the engagement claw is exposed from the inside of the second cylindrical body and easily engages with the engagement portion of the second cylindrical body. This restricts the movement of the needle cover toward the base end. In this way, by combining the snap fit with the second cylindrical body, it is easy to switch between restricting the movement of the needle cover and allowing its movement.

[0022] (4) In the drug solution administration device described in item (3) above, in a pre-detachment stage for removing the puncture needle from the base portion after the removal stage, a force in the base direction is applied to the needle cover to contract the elastic member, and the engaging claw of the snap fit is disengaged from the engaging portion of the second cylindrical body and inserted into the inside of the second cylindrical body, allowing movement of the needle cover in the base direction.

[0023] This configuration allows the puncture needle to be easily removed from the base.

[0024] (5) In the drug solution administration device described in item (4) above, a force in the base end direction may be applied to the needle cover via a needle cap that covers the puncture needle, causing the elastic member to contract, and the needle cover to move in the base end direction so that the puncture needle is enclosed within the needle cap.

[0025] In this case, the puncture needle detached from the base is enclosed in the needle cap, thereby preventing the puncture needle detached from the base from erroneously puncturing a living body.

[0026] (6) In the drug solution administration device described in the above item (1), the movement restriction mechanism may have, as the restriction member, a rotor rotatable around a central axis of the cylindrical body as a rotation center, the cylindrical body having a first cam portion and a cam groove adjacent to the first cam portion, the needle cover having a second cam portion at a base end, and the rotor having a rib formed on an outer circumferential surface and protruding outward in a diametrical direction. In the mounting step, the rotor rotates and the rib moves from the first cam portion to the second cam portion, and when a force acting on the needle cover toward the base end is removed after the mounting step, the elastic member may stretch and the rotor moves toward the tip end, and the rib may engage with the second cam portion of the needle cover while being positioned in the cam groove, and the rib may push the needle cover toward the base end.

[0027] By attaching the puncture needle to the base, the needle cover cannot be moved in the proximal direction by a small force, i.e., the drug solution administration device can be brought into a state in which the movement of the needle cover is gently restricted.

[0028] (7) In the drug solution administration device described in item (6) above, in a pre-detachment stage for removing the puncture needle from the base portion after the removal stage, a force in the base direction is applied to the needle cover via a needle cap placed on the puncture needle, causing the elastic member to contract and the rotor to move in the base direction and rotate, and in a detachment stage for removing the needle cap and the puncture needle from the base portion, the elastic member extends, causing the rotor and the needle cover to move in the tip direction and the rotor to rotate, and the rib moves from the second cam portion to the first cam portion outside the cam groove.

[0029] The puncture needle can be easily removed from the base by pressing the needle cap against the needle cover and moving the needle cover in the proximal direction, and the movement restriction mechanism returns to a state in which the puncture needle can be reattached to the base.

[0030] (8) In the drug solution administration device described in any one of items (1) to (7) above, the puncture needle may be contained in a needle cap, and during the installation step, a force toward the base end is applied to the needle cover via the needle cap.

[0031] In order to maintain the sterility after sterilization, the puncture needle may be provided in a sealed state housed in a needle cap. When attaching the puncture needle to the base, the needle cover can be moved in the proximal direction using the needle cap housing the puncture needle. In other words, it is not necessary to remove the puncture needle from the needle cap and attach it to the base. This makes it easy to attach the puncture needle to the base.

[0032] (9) In the drug solution administration device described in any one of items (1) to (8) above, in an initial stage before the puncture needle is attached to the base portion, the tip of the needle cover may be located more distal than the tip of the base portion, and the needle cover may surround the outer periphery of the base portion.

[0033] Since the needle cover surrounds the base, it is possible to keep the base clean.

[0034] (10) The drug solution administration device according to any one of the above items (1) to (9) may further include a grip that is detachably attached to a base end of the reservoir holder.

[0035] When the amount of liquid medicine in the reservoir falls below a predetermined amount, the reservoir holder can be replaced with a reservoir filled with liquid medicine, allowing the grip to be used repeatedly. Effect of the Invention

[0036] According to the present invention, the outer circumference of the needle is surrounded by the needle cover in the pre-use stage after the puncture needle is attached to the base of the reservoir and in the removal stage in which the puncture needle that has punctured the body is removed from the body. If a small force is applied to the needle cover in the removal stage, the needle cover is prevented from moving in the proximal direction. This prevents the puncture needle from being exposed from the needle cover in an unexpected situation. For these reasons, the puncture needle is prevented from accidentally puncturing the body of a living body. [Brief description of the drawings]

[0037] [Figure 1] FIG. 1 is a schematic cross-sectional view of a main part of a drug solution administration device according to a first embodiment, as viewed in a direction perpendicular to the axial direction. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the essential parts showing a state in which the needle cover is pushed in the proximal direction by the needle cap and the puncture needle is attached to the base portion of the reservoir. [Diagram 3] FIG. 3 is a schematic cross-sectional view of the essential parts showing a state in which the needle cap has been detached from the puncture needle and the needle cover has moved in the distal direction. [Figure 4] FIG. 4 is a schematic cross-sectional view of a main part showing a state in which the puncture needle has been inserted into the body of a patient. [Diagram 5] FIG. 5 is a schematic cross-sectional view of a main part of a drug solution administration device according to a second embodiment, as viewed from a direction perpendicular to the axial direction. [Figure 6]FIG. 6 is a schematic cross-sectional view of the essential parts showing a state in which the needle cover is pushed in the proximal direction by the needle cap and the puncture needle is attached to the base portion of the reservoir. [Figure 7] FIG. 7 is a schematic cross-sectional view of the essential parts, showing a state in which the needle cap has been detached from the puncture needle and the needle cover is in the middle of moving in the direction toward the tip. [Figure 8] FIG. 8 is a schematic cross-sectional view of the essential parts, showing a state in which the needle cover has moved further in the distal direction from the state shown in FIG. 7 and has stopped. [Figure 9] FIG. 9 is a schematic cross-sectional view of a main part showing a state in which the puncture needle has been inserted into the body of a patient. [Figure 10] FIG. 10 is a schematic cross-sectional view of the essential parts, showing a state in which the needle cover has moved in the distal direction and stopped after the puncture needle has been removed from the patient's body. [Figure 11] FIG. 11 is a schematic cross-sectional view of the essential parts showing a state in which the needle cover is pushed in the proximal direction by the needle cap in order to detach the puncture needle from the base. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] In the following, a patient will be exemplified as a living body.

[0039] Fig. 1 is a schematic cross-sectional view of a main part of a drug solution administration device 10 according to a first embodiment. The drug solution administration device 10 includes a reservoir holder 42 for holding a syringe-type reservoir 40. Fig. 1 shows a state in which the reservoir 40 is held by the reservoir holder 42. The reservoir 40 is detachable from the reservoir holder 42. A drug solution such as insulin is stored in the reservoir 40.

[0040] The reservoir holder 42 is a generally hollow cylinder, and the reservoir 40 is held by the reservoir holder 42 while being disposed inside the hollow of the reservoir holder 42. The tip of the reservoir 40 has a small-diameter base 44. The base 44 is a hollow cylinder, and a first screw portion is provided on the outer circumferential surface. The base 44 is provided with a rubber sealing plug. The sealing plug prevents the drug solution in the reservoir 40 from leaking out of the reservoir 40. Note that the first screw portion on the outer circumferential surface of the base 44, the fitting portion at the tip of the reservoir 40, and the sealing plug are publicly known, and therefore are not shown in the figures. The base end of the reservoir 40 is sealed with a rubber stopper (not shown), and a pusher that is linked to a rotary button 52 (described later) is connected to the stopper.

[0041] The puncture needle 20 is detachably attached to the base 44 of the reservoir 40. FIG. 1 shows a state (initial stage) before the puncture needle 20 is attached to the base 44. The puncture needle 20 is held by the needle holder 22 and constitutes a needle unit 24 together with the needle holder 22. The needle unit 24 is contained in a dome-shaped needle cap 28 with a protective sleeve 26 covering the portion of the puncture needle 20 exposed from the needle holder 22. An annular engagement portion 29 with which the needle holder 22 engages is provided inside the needle cap 28. A release sheet 30 is attached to one open end of the needle cap 28. A second screw portion (not shown) is provided on the inner peripheral surface of the needle holder 22.

[0042] The base end of the reservoir holder 42 has a flange 46. An insertion hole (not shown) is formed in the flange 46. The tip of the grip 50 is detachably connected to the insertion hole. That is, the grip 50 is detachably attached to the base end of the reservoir holder 42. The central axis C1 of the reservoir holder 42 and the central axis C2 of the grip 50 are aligned on the same line. The outer diameter of the grip 50 is slightly larger than the outer diameter of the reservoir holder 42 and slightly smaller than the outer diameter of the flange 46. The grip 50 extends from the base end of the reservoir holder 42 in the base end direction. The grip 50 is a portion that a user holds when inserting the puncture needle 20 into the patient's body BD (see FIG. 4) to administer a medicinal liquid to the patient.

[0043] A rotation button 52 that functions both as a button and a dial is provided at the base end of the grip 50. The rotation button 52 can be rotated around the central axis C2 of the grip 50 by a user's operation. This operation adjusts the amount of medicinal liquid administered to the patient. The rotation button 52 can be moved along the axial direction (direction along the central axes C1, C2) of the medicinal liquid administration device 10 by a user's operation. When the user presses the rotation button 52 from the initial position toward the tip end with a finger or the like, the medicinal liquid in the reservoir 40 moves to the lumen of the puncture needle 20. When the user releases his / her finger or the like from the rotation button 52, the rotation button 52 moves toward the base end.

[0044] Although not shown, the grip 50 is provided with a display unit that displays the dosage of the medicinal liquid as a numerical value. The numerical value on the display unit changes as the rotation button 52 is rotated. The user can adjust the dosage of the medicinal liquid to a desired amount by rotating the rotation button 52 while checking the numerical value on the display unit.

[0045] The drug solution administration device 10 further includes an outer cylinder 62 as a cylindrical body 60, a needle cover 70, and a movement restriction mechanism 90. The outer cylinder 62 is supported by the reservoir holder 42 at a position where it covers the outer periphery of the reservoir holder 42. The tip and base ends of the outer cylinder 62 are open ends, and the tip of the outer cylinder 62 has an inner flange 64.

[0046] The needle cover 70 has a cover body 72, an opening 74 provided at the tip of the cover body 72, and an outer flange 76 provided at the base end of the cover body 72. The cover body 72 can be exposed from the tip (open end) of the outer tube 62. The base end face of the inner flange 64 of the outer tube 62 abuts against the tip face of the outer flange 76 of the needle cover 70, thereby preventing the cover body 72 from coming off the outer tube 62. The inner periphery of the cover body 72 has a guide hole 78, and the inner periphery of the outer flange 76 has an escape hole 80. The diameter of the escape hole 80 is larger than the diameter of the guide hole 78.

[0047] In the first embodiment, the movement restricting mechanism 90 has a snap fit 100 as the restricting member 92 , a coil spring 120 as the elastic member 94 , and an inner tube 130 as the second cylindrical body 96 .

[0048] The inner tube 130 is disposed inside the outer tube 62. The inner tube 130 has an inner hole 132 extending along the axial direction. The base end of the inner tube 130 is approximately at the same position as the base end of the outer tube 62 in the axial direction of the medical solution administration device 10. The base end of the inner tube 130 has a blocking wall 134. The blocking wall 134 blocks the base end (open end) of the outer tube 62. The blocking wall 134 has an insertion hole 136 for passing the reservoir holder 42 therethrough. The outer tube 62 is supported by the reservoir holder 42 via the inner tube 130. The base end surface of the blocking wall 134 abuts against the tip surface of the flange portion 46.

[0049] The tip of the inner tube 130 has an annular engagement portion 142 which is an engagement object 140. The annular engagement portion 142 is an annular portion which protrudes inward in the diameter direction of the inner tube 130 at the tip of the inner tube 130. An accommodating hole 144 is formed on the inner circumference of the annular engagement portion 142. The accommodating hole 144 is connected to the inner hole 132. The inner diameter of the accommodating hole 144 is smaller than the inner diameter of the inner hole 132.

[0050] The axial length of the inner cylinder 130 is smaller than the axial length of the outer cylinder 62. Therefore, in the axial direction of the drug solution administration device 10, the annular engagement portion 142 at the tip of the inner cylinder 130 (the tip surface of the inner cylinder 130) is located closer to the base end than the tip of the outer cylinder 62 (the tip surface of the inner flange 64). The reservoir holder 42 is passed through the inner hole 132.

[0051] The snap fit 100 has an annular portion 102, legs 104 extending from the annular portion 102 toward the tip, and engagement claws 106 provided on the free end side (tip side) of the legs 104. In the illustrated example, there are four legs 104 and four engagement claws 106. Two of the four legs 104 and four engagement claws 106 are shown in FIG.

[0052] The base end of the engagement claw 106 is located at approximately the center of the leg 104 in the axial direction. The engagement claw 106 expands toward the outside in the diametric direction of the annular portion 102 as it moves from the tip to the base end. Therefore, the base end surface 108 of the engagement claw 106 is located outside the diametric direction of the annular portion 102 more than the outer circumferential surface 110 of the leg 104. In the initial stage before the puncture needle 20 is attached to the base portion 44, the tip of the engagement claw 106 is located in the escape hole 80 of the outer flange 76 of the needle cover 70. The base end surface 108 of the engagement claw 106 abuts against the annular engagement portion 142 (the tip surface of the inner tube 130) of the inner tube 130. Due to this abutment, the engagement claw 106 is engaged with the annular engagement portion 142. The annular portion 102 and the leg 104 are inserted into the inner hole 132 inside the inner tube 130.

[0053] The engagement object 140 is not limited to the annular engagement portion 142 (the tip surface of the inner tube 130) of the inner tube 130. For example, an engagement protrusion protruding inward in the diameter direction of the outer tube 62 may be provided on the inner circumferential surface of the outer tube 62, and this engagement protrusion may be used as the engagement object 140.

[0054] The coil spring 120 is disposed in an inner hole 132 of the inner tube 130 and passed through the base end of the reservoir holder 42. The tip of the coil spring 120 abuts against the base end surface of the annular portion 102 of the snap fit 100. The base end of the coil spring 120 abuts against the inner surface of the base end of the inner tube 130. Therefore, the coil spring 120 biases the snap fit 100 in the tip direction.

[0055] Next, a method for administering a medicinal liquid to a patient using the medicinal liquid administration device 10 will be described. Note that, although a typical example of a user in the following description is a patient, the user is not limited to a patient. The user may be a medical professional such as a doctor. The same applies to the second embodiment described later.

[0056] FIG. 1 shows an initial stage before the puncture needle 20 is attached to the base portion 44 of the reservoir 40. In the initial stage, no force is applied to the needle cover 70 to push the needle cover 70 toward the base end, so the needle cover 70 does not move along the axial direction. The tip of the needle cover 70 is located on the tip side of the tip of the base portion 44, and the cover body 72 of the needle cover 70 surrounds the outer periphery of the base portion 44. Note that the coil spring 120 is in an extended state, and the snap fit 100 is biased toward the tip by the coil spring 120. The base end surface 108 of the engagement claw 106 of the snap fit 100 is engaged with the annular engagement portion 142 of the inner cylinder 130.

[0057] Next, the user disinfects the base 44 with ethanol or the like, and then attaches the puncture needle 20 to the base 44 in the attachment stage, as shown in FIG. 2. In this case, the user peels off the release sheet 30 (see FIG. 1) from the needle cap 28. This opens one end of the needle cap 28. The user abuts the open one end of the needle cap 28 against the tip of the cover body 72 of the needle cover 70, and then pushes the needle cap 28 toward the base end. This applies a force to the needle cover 70 that pushes the needle cover 70 toward the base end. Therefore, the needle cap 28 and the needle cover 70 move toward the base end.

[0058] As the needle cover 70 moves in the proximal direction, the engaging claw 106 (the tip of the leg 104) of the snap fit 100 is inserted into the guide hole 78 of the cover body 72 of the needle cover 70. As a result, the tip of the engaging claw 106 is pushed toward the inside in the diametric direction of the cover body 72 by the inner peripheral surface of the guide hole 78, contracting to become slightly narrower. As a result, the engagement between the proximal end surface 108 of the engaging claw 106 and the annular engaging portion 142 of the inner tube 130 is released. In other words, the snap fit 100 is released from the restraint of the annular engaging portion 142.

[0059] The force with which the user presses the needle cover 70 via the needle cap 28 is sufficiently greater than the elastic force of the coil spring 120. Therefore, the needle cover 70 and the snap fit 100 move together in the proximal direction. The engagement claw 106, which has contracted diametrically inward of the cover body 72, is easily inserted into the receiving hole 144 or the inner hole 132 of the inner tube 130. In other words, the engagement claw 106 is inserted into the interior of the inner tube 130, which is the second cylindrical body 96. As the snap fit 100 rises in the proximal direction, the coil spring 120 is compressed along the axial direction.

[0060] As the needle holder 22 covers the base portion 44 and the base end surface of the needle holder 22 abuts against the tip surface of the reservoir 40, the movement of the needle cap 28 and the needle cover 70 in the base direction stops. Compression of the coil spring 120 also stops. At this point, the base end of the puncture needle 20 is pierced through a sealing plug (not shown) and inserted into the reservoir 40 (see FIG. 1). In this state, the user rotates the needle unit 24 together with the needle cap 28, and screws the second screw portion of the needle holder 22 into the first screw portion of the base portion 44. This connects the needle unit 24 to the base portion 44 (see FIG. 2).

[0061] The user then pulls the needle cap 28 toward the distal end. Since the needle unit 24 is connected to the base portion 44, the needle unit 24 is placed in the reservoir 40, and the needle cap 28 is detached from the needle unit 24, as shown in FIG. 3. Accordingly, the force pushing the needle cover 70 toward the proximal end is removed from the needle cover 70. Therefore, the compressed coil spring 120 expands, and pushes the annular portion 102 of the snap fit 100 toward the distal end. That is, the snap fit 100 is biased toward the distal end based on the elastic force of the coil spring 120.

[0062] As a result, the snap fit 100 moves toward the tip. Because the tip of the engagement claw 106 of the snap fit 100 is inserted into the guide hole 78 of the needle cover 70, the snap fit 100 pushes the needle cover 70. Therefore, the needle cover 70 moves toward the tip together with the snap fit 100. The snap fit 100 and the needle cover 70 return to the same positions as in the initial stage, resulting in the state shown in Figure 3. Note that Figure 3 shows the state in which the protective sleeve 26 (see Figure 1) has been removed from the puncture needle 20.

[0063] By the above movement, the engaging claws 106 of the snap fit 100 are exposed from the inner hole 132 and the accommodation hole 144 of the inner cylinder 130. When the base end surface 108 of the engaging claws 106 is exposed from the inner hole 132 and the accommodation hole 144, the engaging claws 106 expand outward in the diameter direction of the annular portion 102. As a result, the engaging claws 106 re-engage with the annular engaging portion 142 of the inner cylinder 130.

[0064] In the initial stage (see FIG. 1), the tip of the needle cover 70 may be in the same position as the tip of the base portion 44. Alternatively, the tip of the needle cover 70 may be located on the proximal side of the tip of the base portion 44. In this case, in the pre-use stage (see FIG. 3) after the attachment stage, the needle cover 70 is moved so that the tip of the needle cover 70 is located on the distal side of the tip of the base portion 44.

[0065] 3 is the pre-use stage. In the pre-use stage, the tip of the needle cover 70, which has moved in the tip direction as the coil spring 120 expands, is positioned further forward than the tip of the puncture needle 20. The cover body 72 of the needle cover 70 surrounds the outer periphery of the tip of the puncture needle 20.

[0066] Next, the user grasps the grip 50 (see FIG. 1 ) and points the tip of the puncture needle 20 vertically upward, and presses the rotation button 52 toward the tip. As a result, a predetermined amount of the medicinal liquid in the reservoir 40 passes through the lumen of the puncture needle 20 and is discharged from the puncture needle 20. This fills the lumen with the medicinal liquid. The user then rotates the rotation button 52 while checking the value on the display, to adjust the amount of medicinal liquid administered. During the above operations, the cover body 72 of the needle cover 70 is maintained in a state in which it surrounds the outer periphery of the tip of the puncture needle 20. This prevents the user from being accidentally punctured by the puncture needle 20.

[0067] The user then grasps the grip 50 and inserts the tip of the puncture needle 20 into the patient's body BD (eg, skin) as shown in Fig. 4. Thus, Fig. 4 shows the puncture stage.

[0068] In the puncturing stage, the tip surface of the cover body 72 of the needle cover 70 abuts against the body BD before the tip of the puncture needle 20 punctures the body BD. When the user presses the grip 50 and the reservoir holder 42 toward the body BD in this state, the needle cover 70 receives a reaction force from the body BD. In other words, a force is applied to the needle cover 70 to move the needle cover 70 toward the base end.

[0069] Thereafter, as in the attachment stage, the coil spring 120 is compressed and the needle cover 70 and the snap fit 100 move together toward the base end. In other words, the snap fit 100 allows the needle cover 70 to move toward the base end. This causes the puncture needle 20 to move relatively toward the tip end. As a result, the tip of the needle cover 70 is located closer to the base end than the tip of the puncture needle 20, and the tip of the puncture needle 20 is exposed from the opening 74 of the cover body 72 of the needle cover 70. The exposed tip of the puncture needle 20 punctures the body BD (skin). When the tip of the needle holder 22 abuts against the body BD, the puncture of the puncture needle 20 stops, and the movement of the needle cover 70 and the snap fit 100 toward the base end stops.

[0070] In this state, the user presses the rotation button 52 toward the tip. The user maintains the state in which the rotation button 52 is pressed for, for example, about 5 to 10 seconds. As a result, an amount of medicinal liquid corresponding to the amount of rotation of the rotation button 52 (the numerical value on the display unit) is administered to the patient from the reservoir 40 (see FIG. 1) via the lumen of the puncture needle 20.

[0071] After administration of the medicinal liquid to the patient is completed, the user removes the puncture needle 20 from the patient's body BD (see FIG. 4) in the removal stage. In the removal stage, the force (reaction force from the body BD) moving the needle cover 70 toward the base end is removed. Therefore, the compressed coil spring 120 expands, and the needle cover 70 and the snap fit 100 move integrally toward the tip end. As a result, the medicinal liquid administration device 10 is in the same state as in FIG. 3. As can be understood from this, FIG. 3 shows the pre-use stage and the removal stage.

[0072] When a predetermined amount or more of the medicinal liquid remains in the reservoir 40, the medicinal liquid administration device 10 can be reused. In order to make the medicinal liquid administration device 10 reusable, the user performs an operation to detach the puncture needle 20 from the base portion 44 in the pre-detachment stage. In this case, the user presses the empty needle cap 28 against the tip of the needle cover 70. Accordingly, a force that moves the needle cover 70 in the proximal direction is applied to the needle cover 70 via the needle cap 28, as in the attachment stage. It is not necessary to cover the puncture needle 20 with the protective sleeve 26.

[0073] Therefore, in the pre-detachment stage, similarly to the attachment stage, the coil spring 120 is compressed and the needle cover 70 and the snap fit 100 move integrally toward the proximal end. As a result, the drug solution administration device 10 is in the same state as that shown in Fig. 2. As can be understood from this, Fig. 2 shows the attachment stage and the pre-detachment stage. However, as described above, the protective sleeve 26 is not placed on the puncture needle 20.

[0074] When needle cap 28 accommodates the entire needle unit 24 and the tip of needle holder 22 engages with annular engagement portion 29, movement of needle cap 28 and needle cover 70 toward the base end stops. Compression of coil spring 120 also stops. In this state, the user rotates needle unit 24 together with needle cap 28 to release the screw engagement between the first threaded portion of base portion 44 and the second threaded portion of needle holder 22. This releases the connection between needle unit 24 and base portion 44.

[0075] Next, in the removal stage, the user pulls the needle cap 28 toward the distal end. Since the connection between the needle unit 24 and the base portion 44 has been released, the needle unit 24 and the needle cap 28 are removed from the reservoir 40 together, as in FIG. 1. Accordingly, the force pushing the needle cover 70 toward the proximal end is removed from the needle cover 70. Therefore, the compressed coil spring 120 expands, and the snap fit 100 and the needle cover 70 return to their original positions. As a result, the medical solution administration device 10 returns to the initial stage shown in FIG. 1.

[0076] From the removal stage and the pre-detachment stage back to the initial stage, the cover body 72 of the needle cover 70 remains surrounding the outer periphery of the tip of the puncture needle 20. Therefore, even in each stage, the user is prevented from being accidentally punctured by the puncture needle 20.

[0077] Thereafter, the above process is repeated to repeatedly administer the medicinal liquid to the patient until the amount of medicinal liquid in the reservoir 40 falls below the predetermined amount. When the amount of medicinal liquid in the reservoir 40 falls below the predetermined amount, the user rotates the rotation button 52 to remove the reservoir 40 from the grip 50. The user then replaces the reservoir 40 with a new one. That is, the user holds the new reservoir 40 in the reservoir holder 42. This makes it possible to reuse the medicinal liquid administration device 10.

[0078] The drug solution administration device 10 according to the first embodiment has the following advantages.

[0079] 1, the drug solution administration device 10 includes a reservoir holder 42 for holding a reservoir 40 that stores a drug solution. The drug solution administration device 10 further includes a cylindrical body 60 supported by the reservoir holder 42, a needle cover 70 having an opening 74 at its tip, and a movement restriction mechanism 90. The needle cover 70 is disposed at the tip of the cylindrical body 60, and is movable in the axial direction of the cylindrical body 60. The movement restriction mechanism 90 restricts movement of the needle cover 70 toward the base end.

[0080] The reservoir 40 has a base portion 44 to which the puncture needle 20, which is inserted into the body BD (see FIG. 4), can be detached. The medicinal liquid in the reservoir 40 is administered into the body BD through the puncture needle 20.

[0081] As shown in FIG. 1, the movement restriction mechanism 90 has a restriction member 92 and an elastic member 94. The restriction member 92 is movable along the axial direction of the cylindrical body 60 within the cylindrical body 60. The elastic member 94 applies an elastic force to the restriction member 92 that moves the restriction member 92 toward the distal end. As a result, the elastic member 94 applies an elastic force to the needle cover 70 via the restriction member 92. The movement restriction mechanism 90 configured in this manner restricts the movement of the needle cover 70 toward the proximal end when a force smaller than the elastic force of the elastic member 94 acts on the needle cover 70. In contrast, when a force equal to or greater than the elastic force of the elastic member 94 acts on the needle cover 70, the movement restriction mechanism 90 allows the needle cover 70 to move toward the proximal end.

[0082] 2, in the stage of attaching the puncture needle 20 to the base portion 44, a force toward the proximal end is applied to the needle cover 70. In this case, the movement restriction mechanism 90 allows the needle cover 70 to move toward the proximal end. Also, the elastic member 94 contracts.

[0083] 3, in the pre-use stage in which the force is removed from the needle cover 70 after the attachment stage, the needle cover 70 moves toward the tip by being pushed by the restricting member 92 as the elastic member 94 stretches. As a result, the tip of the needle cover 70 is positioned closer to the tip of the puncture needle 20 than the tip of the puncture needle 20, and the needle cover 70 surrounds the outer periphery of the puncture needle 20.

[0084] 4, in the puncture stage in which the puncture needle 20 is inserted into the patient's body BD, a force is applied to the needle cover 70 in the proximal direction from the body BD, and the restricting member 92 allows the needle cover 70 to move in the proximal direction. In addition, the elastic member 94 contracts, and the tip of the needle cover 70 is positioned closer to the proximal end than the tip of the puncture needle 20, so that the puncture needle 20 is exposed from the opening 74.

[0085] In the removal stage where the puncture needle 20 is removed from the patient's body BD, the needle cover 70 moves toward the tip by being pushed by the restricting member 92 as the elastic member 94 expands. As a result, the tip of the needle cover 70 is positioned more distal than the tip of the puncture needle 20, and the needle cover 70 surrounds the outer periphery of the puncture needle 20. In other words, the medicinal solution administration device 10 is in the same state as that shown in FIG.

[0086] As can be seen from the above, the outer periphery of the puncture needle 20 is surrounded by the needle cover 70 in the pre-use stage and the removal stage. Therefore, the puncture needle 20 is prevented from accidentally puncturing the user's body BD or the patient's body BD. In other words, the needle cover 70 can prevent accidental puncture. Moreover, when a force is applied to push the needle cover 70 in the proximal direction, the needle cover 70 easily moves in the proximal direction. Therefore, the needle cover 70 does not prevent the puncture needle 20 from puncturing the patient's body BD.

[0087] Furthermore, in the removal step, if the force applied to the needle cover 70 is small, the needle cover 70 is prevented from moving in the proximal direction. This prevents the puncture needle 20 from being exposed from the needle cover 70 in an unexpected situation.

[0088] As shown in Fig. 1, the movement restriction mechanism 90 has a snap fit 100 having an engagement claw 106 as a restriction member 92. Movement of the needle cover 70 in the proximal direction is restricted based on the engagement of the engagement claw 106 with an engagement target 140. In contrast, as shown in Figs. 2 and 4, movement of the needle cover 70 in the proximal direction is permitted based on the release of the engagement of the engagement claw 106 with the engagement target 140.

[0089] According to the movement restricting mechanism 90 including the snap fit 100, by switching between an engaged state and a disengaged state, it is possible to easily switch between restricting movement of the needle cover 70 and allowing movement.

[0090] 1, the movement restriction mechanism 90 has a second cylindrical body 96 (inner cylinder 130 in the first embodiment) disposed inside the cylindrical body 60 (outer cylinder 62 in the first embodiment). The engagement claw 106 of the snap fit 100 engages with an engagement portion provided on the second cylindrical body 96 in the pre-use stage and the removal stage. In contrast, the engagement claw 106 of the snap fit 100 is disengaged from the engagement portion and inserted into the inside of the second cylindrical body 96 (inner hole 132) in the attachment stage and the puncture stage.

[0091] As shown in Figs. 2 and 4, when the tip of the snap fit 100 is pushed from the base end of the needle cover 70, the engagement of the engagement claw 106 with the engagement portion of the second cylindrical body 96 is easily released, and the needle cover 70 is allowed to move in the base end direction. The engagement claw 106 is inserted into the second cylindrical body 96. On the other hand, when an elastic force toward the tip direction is applied to the needle cover 70 from the elastic member 94, the engagement claw 106 is exposed from the inside of the second cylindrical body 96 and easily engages with the engagement portion of the second cylindrical body 96. This restricts the movement of the needle cover 70 in the base end direction. In this way, by combining the snap fit 100 with the second cylindrical body 96, it is easy to switch between restricting the movement of the needle cover 70 and allowing the movement.

[0092] In a pre-detachment stage for removing the puncture needle 20 from the base portion 44 after the removal stage, a force toward the base end is applied to the needle cover 70, causing the elastic member 94 to contract. The engagement claw 106 of the snap fit 100 is released from engagement with the engagement portion of the second cylindrical body 96 and is inserted into the inside (inner hole 132) of the second cylindrical body 96. That is, the medical solution administration device 10 is in the same state as that shown in FIG.

[0093] Since the needle cover 70 moves in the proximal direction, the puncture needle 20 can be easily removed from the base portion 44.

[0094] In a pre-removal stage for removing the puncture needle 20 from the base 44, the needle cap 28 is used to push the needle cover 70 in the proximal direction (see FIG. 2). When a force in the proximal direction is applied to the needle cover 70 via the needle cap 28, the needle cover 70 moves in the proximal direction and the elastic member 94 contracts. The needle cap 28 is placed over the puncture needle 20. In other words, the puncture needle 20 is contained within the needle cap 28.

[0095] The puncture needle 20 detached from the base 44 is in a state of being enclosed in the needle cap 28. Therefore, the puncture needle 20 detached from the base 44 is prevented from accidentally puncturing the user's body BD or the patient's body BD.

[0096] In order to maintain the sterility of the puncture needle 20 after sterilization, the puncture needle 20 may be provided in a sealed state housed in a needle cap 28. In this case, during the attachment step, a force in the proximal direction can be applied to the needle cover 70 via the needle cap 28.

[0097] That is, the needle cover 70 can be moved in the proximal direction using the needle cap 28 that contains the puncture needle 20. Therefore, it is not necessary to remove the puncture needle 20 from the needle cap 28 and attach it to the base part 44. This makes it easy to attach the puncture needle 20 to the base part 44.

[0098] As shown in FIG. 1, in the initial stage before the puncture needle 20 is attached to the base portion 44, the tip of the needle cover 70 is located further forward than the tip of the base portion 44, and the needle cover 70 surrounds the outer periphery of the base portion 44.

[0099] The drug solution administration device 10 includes a grip 50 that is detachably attached to an axial end of the reservoir holder 42 .

[0100] When the amount of medicinal liquid in the reservoir 40 falls below a predetermined amount, the reservoir holder 42 can be replaced with a reservoir 40 that is filled with medicinal liquid. The grip 50 can be used repeatedly.

[0101] Next, a drug solution administration device 200 according to a second embodiment will be described with reference to Fig. 5 to Fig. 11. Note that the same components as or corresponding components shown in Fig. 1 to Fig. 4 are designated by the same names, and detailed description thereof will be omitted.

[0102] Fig. 5 is a schematic cross-sectional view of a main part of a drug solution administration device 200 according to a second embodiment. The drug solution administration device 200 includes a reservoir holder 204 that holds a reservoir 202. Fig. 5 shows a state in which the reservoir 202 is detachably held by the reservoir holder 204. A drug solution such as insulin is stored in the reservoir 202. The tip of the reservoir 202 has a seat portion 206, and a first screw portion (not shown) is provided on the outer circumferential surface of the seat portion 206.

[0103] The reservoir holder 204 supports a cylindrical body 60. In the second embodiment, the cylindrical body 60 is a cam barrel 210. The tip and base ends of the cam barrel 210 are open ends, and the tip has an inner flange 212. The opening at the base end of the cam barrel 210 is closed by a closing wall 216. In the illustrated example, the inner circumferential surface of the cam barrel 210 has a plurality of protrusions 218. Each protrusion 218 protrudes radially inward of the cam barrel 210 and extends along the axial direction of the cam barrel 210.

[0104] The multiple protrusions 218 are aligned at intervals from one another along the circumferential direction of the cam barrel 210. Based on this spacing, cam grooves 220 are formed between adjacent protrusions 218.

[0105] Each protrusion 218 has a first cam portion 222 at its base end. Specifically, a recess recessed toward the tip end is formed at the base end of the protrusion 218. This recess is the first cam portion 222. The first cam portion 222 has a parallel surface 224 extending parallel to the axial direction of the cam barrel 210 at the base end and approximately the center in the circumferential direction of the protrusion 218. The first cam portion 222 has a first cam surface 226 extending from one end in the circumferential direction of the protrusion 218 toward the parallel surface 224 at the base end of the protrusion 218. The first cam surface 226 is inclined toward the tip end as it approaches the parallel surface 224 from one end in the circumferential direction of the protrusion 218.

[0106] Each protrusion 218 has a guide surface 228 at its base end. The guide surface 228 is an inclined surface that extends from approximately the circumferential center at the base end of the protrusion 218 toward the other end in the circumferential direction. The guide surface 228 is inclined from approximately the circumferential center of the protrusion 218 toward the tip end as it approaches the other end in the circumferential direction. The inclination angle of the first cam surface 226 with respect to the axial direction and the inclination angle of the guide surface 228 with respect to the axial direction are approximately equal to each other.

[0107] The needle cover 230 has a cover body 232, an opening 234 provided at the tip of the cover body 232, and an outer flange 236 provided at the base end of the cover body 232. The cover body 232 can be exposed from the tip (open end) of the cam barrel 210. The base end face of the inner flange 212 of the cam barrel 210 abuts against the tip face of the outer flange 236 of the needle cover 230, thereby preventing the cover body 232 from coming off the cam barrel 210.

[0108] A plurality of second cam portions 240 and a plurality of protrusions 242 are alternately arranged at the base end of the outer flange 236. Each second cam portion 240 is formed of one recess. That is, the needle cover 230 has a plurality of second cam portions 240 arranged along the circumferential direction of the outer flange 236. Adjacent two of the plurality of second cam portions 240 are separated by a protrusion 242. The second cam portion 240 has a second cam surface 244 inclined with respect to the axial direction.

[0109] In the second embodiment, the movement restriction mechanism 90 has a rotor 250 as a restriction member 92, a collar 270, a moving plate 274, and a coil spring 280. The rotor 250 is movable along the axial direction within the cam barrel 210, and is rotatable within the cam barrel 210 about the central axis of the rotor 250. The coil spring 280 applies an elastic force to the rotor 250 in the tip direction via the moving plate 274 and the collar 270.

[0110] The rotor 250 has a large diameter cylindrical portion 252 and a small diameter cylindrical portion 254 connected to the base end of the large diameter cylindrical portion 252. In the illustrated example, the outer circumferential surface of the large diameter cylindrical portion 252 has a plurality of ribs 256. The number of the ribs 256 is the same as the number of the first cam portions 222. The tip of the rib 256 has a third cam surface 258. The inclination angle of the third cam surface 258 with respect to the axial direction is the same as the inclination angle of the first cam surface 226 with respect to the axial direction. FIG. 5 shows a state in which the tip of the rib 256 engages with the first cam portion 222 and the first cam surface 226 and the third cam surface 258 face each other.

[0111] The small diameter cylindrical portion 254 is inserted into the collar 270. The inner diameter of the collar 270 is larger than the outer diameter of the small diameter cylindrical portion 254. Therefore, the inner peripheral surface of the collar 270 and the outer peripheral surface of the small diameter cylindrical portion 254 are spaced apart by a predetermined distance. That is, a play is formed between the inner peripheral surface of the collar 270 and the outer peripheral surface of the small diameter cylindrical portion 254. In addition, the axial length of the collar 270 is larger than the axial length of the small diameter cylindrical portion 254. The outer diameter of the collar 270 is smaller than the outer diameter of the large diameter cylindrical portion 252. Therefore, when the tip surface of the collar 270 abuts against the base end surface of the large diameter cylindrical portion 252 with the small diameter cylindrical portion 254 inserted inside the collar 270, the entire small diameter cylindrical portion 254 is accommodated inside the collar 270.

[0112] The moving plate 274 is disposed in the cam barrel 210 such that the tip surface of the moving plate 274 abuts against the base end surface of the collar 270. The moving plate 274 is formed with an insertion hole 276 for passing the reservoir holder 204 therethrough.

[0113] The coil spring 280 is disposed between the moving plate 274 and the closing wall 216. The tip of the coil spring 280 abuts against the base end surface of the moving plate 274. The base end of the coil spring 280 abuts against the tip surface of the closing wall 216. Therefore, the elastic force of the coil spring 280 is applied to the large diameter cylinder portion 252 of the rotor 250 via the moving plate 274 and the collar 270. However, in the state shown in FIG. 5 (initial stage), the rib 256 of the rotor 250 is engaged with the first cam portion 222, and therefore the rotor 250, the collar 270, and the moving plate 274 are prevented from moving in the tip direction.

[0114] Similar to the drug solution administration device 10 according to the first embodiment, a grip 50 is connected to the base end of the reservoir holder 204. The grip 50 is provided with a rotation button 52 and a display unit.

[0115] Next, a method for administering a medicinal liquid to a patient using the medicinal liquid administration device 200 will be described.

[0116] FIG. 5 shows an initial stage before the puncture needle 20 is attached to the base portion 206 of the reservoir 202. In the initial stage, no force is applied to the needle cover 230 to push the needle cover 230 toward the base end, so the needle cover 230 does not move along the axial direction. The tip of the needle cover 230 is located on the tip side of the tip of the base portion 206, and the cover body 232 of the needle cover 230 surrounds the outer periphery of the base portion 206. The coil spring 280 is compressed along the axial direction, and the elastic force of the coil spring 280 is applied to the large diameter cylindrical portion 252 of the rotor 250 via the moving plate 274 and the collar 270. However, as described above, the rib 256 of the rotor 250 is engaged with the first cam portion 222, so that the rotor 250, the collar 270, and the moving plate 274 are prevented from moving toward the tip end.

[0117] Next, the user peels off the release sheet 30 from the needle cap 28, and then attaches the puncture needle 20 to the base portion 206 in the attachment stage shown in Fig. 6. In this case, the user abuts one end of the needle cap 28 against the tip of the cover body 232 of the needle cover 230, and then pushes the needle cap 28 toward the base end. This causes a force to act on the needle cover 230, pushing the needle cover 230 toward the base end.

[0118] The force with which the user presses the needle cover 230 via the needle cap 28 is sufficiently greater than the elastic force of the coil spring 280. Therefore, the needle cover 230 moves toward the base end. Due to this movement, the rib 256 of the rotor 250 is pressed by the convex portion 242 of the needle cover 230 and disengages from the first cam portion 222. That is, the engagement of the rib 256 with the first cam portion 222 is released. Therefore, the rotor 250 moves toward the base end together with the needle cover 230. By moving the rotor 250 in this manner, the tip of the rib 256 is guided by the second cam surface 244 of the second cam portion 240. As a result, the rotor 250 rotates and the tip of the rib 256 moves from the first cam portion 222 of the cam barrel 210 to the second cam portion 240 of the needle cover 230.

[0119] Since the small diameter cylindrical portion 254 of the rotor 250 is inserted into the collar 270 with some play, the small diameter cylindrical portion 254 is prevented from being subjected to the restrictive forces of the collar 270, the moving plate 274, and the coil spring 280. Therefore, the rotor 250 rotates easily.

[0120] As the rotor 250 moves in the proximal direction, the collar 270 and the moving plate 274 move in the proximal direction integrally with the rotor 250. Due to this movement, the coil spring 280 is further compressed along the axial direction.

[0121] As the needle holder 22 covers the base portion 206 and the base end surface of the needle holder 22 abuts against the tip surface of the reservoir 202, the movement of the needle cap 28 and the needle cover 230 in the base direction stops. The compression of the coil spring 280 also stops. At this point, the base end of the puncture needle 20 is pierced through a sealing plug (not shown) and inserted into the reservoir 202 (see FIG. 5). In this state, the user rotates the needle unit 24 together with the needle cap 28, and screws the second screw portion of the needle holder 22 into the first screw portion of the base portion 206. This connects the needle unit 24 to the base portion 206 (see FIG. 6).

[0122] The user then pulls the needle cap 28 toward the distal end. Since the needle unit 24 is connected to the base portion 206, as shown in FIG. 7, the needle unit 24 is placed in the reservoir holder 204, and the needle cap 28 begins to detach from the needle unit 24. Accordingly, the force pushing the needle cover 230 toward the proximal end is removed from the needle cover 230. Therefore, the compressed coil spring 280 expands. As a result, the elastic force of the coil spring 280 is applied to the large diameter cylindrical portion 252 of the rotor 250 via the moving plate 274 and the collar 270. That is, the coil spring 280 pushes the large diameter cylindrical portion 252 of the rotor 250 toward the distal end.

[0123] As a result, the moving plate 274, the collar 270, and the rotor 250 move integrally toward the tip. During this movement, as shown in FIG. 7, the third cam surface 258 of the rib 256 abuts against the guide surface 228 while abutting against the second cam surface 244. As the moving plate 274, the collar 270, and the rotor 250 move further toward the tip, the convex portion 242 of the needle cover 230 is positioned at the base end of the cam groove 220, and the third cam surface 258 of the rib 256 is guided by the guide surface 228, causing the rotor 250 to rotate. As a result, the tip of the rib 256 is inserted into the base end of the cam groove 220. Since the rotor 250 is rotating, the third cam surface 258 of the rib 256 transfers from the second cam surface 244 of the second cam portion 240 to the second cam surface 244 of another second cam portion 240 adjacent to the second cam portion 240 in the cam groove 220.

[0124] In this state, the rib 256 no longer receives a reaction force from the projection 218, so the coil spring 280 expands as shown in Fig. 8. Therefore, the needle cover 230, the rotor 250, the collar 270 and the moving plate 274 move in the distal direction due to the elastic force of the coil spring 280. When the distal end surface of the outer flange 236 of the needle cover 230 abuts against the proximal end surface of the inner flange 212 of the cam barrel 210, the movement of the needle cover 230, the rotor 250, the collar 270 and the moving plate 274 in the distal direction stops, resulting in the state shown in Fig. 8. The needle cover 230 returns to the same position as in the initial stage. Note that Fig. 8 shows a state in which the protective sleeve 26 (see Fig. 5) has been removed from the puncture needle 20.

[0125] 8 is the pre-use stage. In the pre-use stage, the tip of the needle cover 230, which has moved in the tip direction as the coil spring 280 expands, is positioned further forward than the tip of the puncture needle 20. The cover body 232 of the needle cover 230 surrounds the outer periphery of the tip of the puncture needle 20.

[0126] The user then fills the lumen with the medicinal liquid in the same manner as in the first embodiment. The user then rotates the rotary button 52 while checking the value on the display to adjust the amount of medicinal liquid administered. During the above operations, the cover body 232 of the needle cover 230 is kept surrounding the outer periphery of the tip of the puncture needle 20. This prevents the user from being accidentally punctured by the puncture needle 20.

[0127] The user then grasps the grip 50 and inserts the tip of the puncture needle 20 into the patient's body BD as shown in Fig. 9. Thus, Fig. 9 shows the puncture stage.

[0128] In the puncturing stage, before the tip of the puncture needle 20 punctures the body BD, the tip surface of the cover body 232 of the needle cover 230 abuts against the body BD. When the user presses the grip 50 and the reservoir holder 204 toward the body BD in this state, the needle cover 230 receives a reaction force from the body BD. In other words, a force is applied to the needle cover 230 to move the needle cover 230 toward the base end.

[0129] Thereafter, as in the attachment stage, the coil spring 280 is compressed and the needle cover 230, the rotor 250, the collar 270 and the moving plate 274 move integrally in the proximal direction. In other words, the rotor 250 allows the needle cover 230 to move in the proximal direction. This causes the puncture needle 20 to move relatively in the distal direction. As a result, the tip of the needle cover 230 is located on the proximal side of the tip of the puncture needle 20, and the tip of the puncture needle 20 is exposed from the opening 234 of the cover body 232 of the needle cover 230. The exposed tip of the puncture needle 20 punctures the body BD (skin). When the tip of the needle holder 22 abuts against the body BD, the puncture of the puncture needle 20 stops, and the movement of the needle cover 230, the rotor 250, the collar 270 and the moving plate 274 in the proximal direction stops.

[0130] During this movement, the rotor 250 does not rotate. Therefore, the rib 256 moves relatively in the cam groove 220 toward the base end while keeping the tip end engaged with the second cam portion 240.

[0131] In this state, when the user presses the rotation button 52 toward the distal end, a predetermined amount of medicinal liquid is administered to the patient from the reservoir 202 (see FIG. 5) through the lumen of the puncture needle 20.

[0132] After administration of the medicinal liquid to the patient is completed, the user removes the puncture needle 20 from the patient's body BD as shown in Fig. 10 (removal stage). In the removal stage, the force (reaction force from the body BD) moving the needle cover 230 toward the base end is removed. Therefore, the compressed coil spring 280 expands, and the needle cover 230, the rotor 250, the collar 270, and the moving plate 274 move integrally toward the tip end. As a result, the needle cover 230 returns to the same position as in the initial stage and the pre-use stage.

[0133] During this movement, the rotor 250 does not rotate. Therefore, the rib 256 moves relatively in the tip direction within the cam groove 220 while keeping the tip engaged with the second cam portion 240.

[0134] When a predetermined amount or more of medicinal liquid remains in the reservoir 202 (see FIG. 5), the medicinal liquid administration device 200 can be reused. To make the medicinal liquid administration device 200 reusable, the user detaches the puncture needle 20 from the base portion 206. To perform this detachment, the user presses an empty needle cap 28 against the tip of the needle cover 230 in the pre-detachment stage, as shown in FIG. 11. Accordingly, a force that moves the needle cover 230 in the base end direction is applied to the needle cover 230 via the needle cap 28, similar to the attachment stage.

[0135] Therefore, in the pre-attachment / detachment stage, similarly to the attachment stage, the coil spring 280 is compressed, and the needle cover 230, the rotor 250, the collar 270, and the moving plate 274 move integrally toward the base end. During this movement, when the tip of the rib 256 is exposed from the base end of the cam groove 220, the rib 256 is released from the restraint of the projection 218, and the third cam surface 258 of the rib 256 slides along the second cam surface 244. In other words, the third cam surface 258 of the rib 256 is guided by the second cam surface 244. As a result, the rotor 250 rotates.

[0136] When needle cap 28 accommodates the entire needle unit 24 and the tip of needle holder 22 engages with annular engagement portion 29, movement of needle cap 28 and needle cover 230 in the proximal direction stops. Compression of coil spring 280 also stops. In this state, the user rotates needle unit 24 together with needle cap 28 to release the screw engagement between the first threaded portion of base portion 206 and the second threaded portion of needle holder 22. This releases the connection between needle unit 24 and base portion 206.

[0137] The user then pulls the needle cap 28 toward the distal end. Because the connection between the needle unit 24 and the base portion 206 has been released, the needle unit 24 and the needle cap 28 are removed from the reservoir 202 together, as in Fig. 5. Accordingly, the force pushing the needle cover 230 toward the proximal end is removed from the needle cover 230. Therefore, the compressed coil spring 280 expands slightly, and the moving plate 274, the collar 270, the rotor 250, and the needle cover 230 move toward the distal end.

[0138] As a result, outside the cam groove 220, the third cam surface 258 of the rib 256 moves from the second cam surface 244 of the second cam portion 240 onto the first cam surface 226 of the first cam portion 222. The third cam surface 258 slides along the first cam surface 226, causing the rotor 250 to rotate. The tip of the rib 256 engages with the first cam portion 222, ending the movement and rotation of the rotor 250. Accordingly, the movement of the collar 270, the moving plate 274, and the needle cover 230 also ends. As a result, the medical solution administration device 200 returns to the initial stage shown in FIG. 5.

[0139] From the removal stage and the detachment stage to the return to the initial stage, the cover body 232 of the needle cover 230 remains surrounding the outer periphery of the tip of the puncture needle 20. Therefore, even in each stage, the user is prevented from being accidentally punctured by the puncture needle 20.

[0140] Thereafter, the above process is repeated to repeatedly administer the medicinal liquid to the patient until the amount of medicinal liquid in the reservoir 202 falls below the predetermined amount. When the amount of medicinal liquid in the reservoir 202 falls below the predetermined amount, the user removes the reservoir 202 from the grip 50. Thereafter, the user replaces the reservoir 202 with a new one, for example. That is, the user holds the new reservoir 202 in the reservoir holder 204. This makes it possible to reuse the medicinal liquid administration device 200.

[0141] According to the drug solution dispensing device 200 of the second embodiment, the same effects as those of the drug solution dispensing device 10 of the first embodiment can be obtained. Moreover, the drug solution dispensing device 200 of the second embodiment has the following effects.

[0142] The movement restriction mechanism 90 has a rotor 250 as a restriction member 92 that is rotatable around the central axis of the cylindrical body 60. In the second embodiment, the cylindrical body 60 is a cam barrel 210 having a first cam portion 222 and a cam groove 220 adjacent to the first cam portion 222. The needle cover 230 has a second cam portion 240 at its base end. The rotor 250 has a rib 256. The rib 256 protrudes diametrically outward from the outer circumferential surface of the rotor 250.

[0143] In the attachment stage shown in Fig. 6, the rib 256 moves from the first cam portion 222 to the second cam portion 240 based on the rotation of the rotor 250. As shown in Figs. 7 and 8, when the force acting in the proximal direction on the needle cover 230 is removed after the attachment stage, the elastic member 94 expands, causing the rotor 250 to move in the distal direction, and the rib 256 engages with the second cam portion 240 of the needle cover 230 with the rib 256 positioned in the cam groove 220. The rib 256 pushes the needle cover 230 in the proximal direction.

[0144] By attaching the puncture needle 20 to the base portion 206, the needle cover 230 is brought into a state in which it cannot be moved in the proximal direction with a small force. In other words, the movement of the needle cover 230 is gently restricted.

[0145] 11, in the pre-detachment stage for removing the puncture needle 20 from the base portion 206 after the removal stage, a force in the proximal direction is applied to the needle cover 230 via the needle cap 28 that is placed on the puncture needle 20. Accordingly, the elastic member 94 contracts, and the rotor 250 moves in the proximal direction and rotates.

[0146] After the pre-removal stage, in the removal stage in which the needle cap 28 and the puncture needle 20 are removed from the base portion 206, the elastic member 94 stretches. As a result, the rotor 250 and the needle cover 230 move toward the tip. The rotor 250 also rotates. With this rotation, the rib 256 moves from the second cam portion 240 to the first cam portion 222 outside the cam groove 220. This causes the medicinal solution administration device 200 to be in the same state as that shown in FIG. 5.

[0147] By pressing the needle cap 28 against the needle cover 230 and moving the needle cover 230 in the proximal direction, the puncture needle 20 can be easily removed from the base portion 206. In addition, the movement restriction mechanism 90 returns to a state in which the puncture needle 20 can be reattached to the base portion 206.

[0148] Possible modifications of the first and second embodiments will be described below.

[0149] The drug solution administration devices 10 and 200 are not limited to cartridge-replaceable devices in which the reservoirs 40 and 202 (reservoir holders 42 and 204) are replaceable as described above. The drug solution administration devices 10 and 200 may be disposable devices that are disposed of as medical waste when the amount of drug solution in the reservoirs 40 and 202 falls below a predetermined amount.

[0150] The medicinal liquid stored in the reservoirs 40, 202 is not limited to insulin. Examples of medicinal liquids other than insulin include GLP-1 receptor agonists.

[0151] The restricting member 92 is not limited to the snap fit 100 or the rotor 250. The restricting member 92 may be a member other than the snap fit 100 or the rotor 250 as long as it is a member that can restrict the movement of the needle cover 70, 230 in the proximal direction.

[0152] The elastic member 94 is not limited to the coil springs 120 and 280. The elastic member 94 may be any object capable of applying an elastic force to the restricting member 92.

[0153] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0154] 10, 200...medicinal solution administration device 20...puncture needle 28... needle cap 40, 202... reservoir 42, 204...Reservoir holder 44, 206...Pedestal part 50…Grip 60…Cylinder 62: Outer barrel 70, 230: Needle cover 74, 234...Opening 90...Movement restriction mechanism 92: Restricting member 94: Elastic member 96...Second cylinder 100...Snap fit 106: Engagement claw; 130: Inner cylinder 142... annular engagement portion 210... cam barrel 218...protrusion 220...cam groove 222...first cam portion 228...guide surface 240: second cam portion; 242: protrusion portion 244...Second cam surface 250...Rotor 256…Rib 258…Third cam surface BD…Body

Claims

1. A drug solution administration device comprising a reservoir holder for holding a reservoir containing a drug solution, a cylinder supported by the reservoir holder; a needle cover disposed at a tip of the cylindrical body so as to be movable in an axial direction of the cylindrical body and having an opening at a tip; a movement restriction mechanism that restricts movement of the needle cover in a proximal direction; Equipped with the movement restriction mechanism includes a restriction member that is movable within the cylindrical body along an axial direction of the cylindrical body, and an elastic member that applies an elastic force to the restriction member such that the restriction member moves toward a distal end direction, thereby applying the elastic force to the needle cover via the restriction member; the movement restriction mechanism restricts movement of the needle cover in the proximal direction when a force smaller than the elastic force of the elastic member acts on the needle cover, and allows movement of the needle cover in the proximal direction when a force equal to or greater than the elastic force of the elastic member acts on the needle cover, The reservoir has a base portion to which a puncture needle can be attached detachably, the puncture needle being punctured into a body of a living organism to administer the medicinal liquid in the reservoir to the body; In an attachment step of attaching the puncture needle to the base portion, a force in a proximal direction is applied to the needle cover, causing the movement restriction mechanism to permit the needle cover to move in the proximal direction and causing the elastic member to contract; In a pre-use stage after the attachment stage in which the force is removed from the needle cover, the needle cover moves in the distal direction by being pushed by the regulating member as the elastic member stretches, so that the distal end of the needle cover is positioned distal to the distal end of the puncture needle, and the needle cover surrounds the outer periphery of the puncture needle, In a puncturing step of puncturing the body with the puncture needle, a force directed from the body in a proximal direction is applied to the needle cover, causing the restricting member to permit the needle cover to move in the proximal direction and the elastic member to contract, and the tip of the needle cover is positioned proximal to the tip of the puncture needle, exposing the puncture needle from the opening, In a removal stage in which the puncture needle is removed from the body, the needle cover moves toward the tip by being pushed by the regulating member as the elastic member stretches, so that the tip of the needle cover is positioned distal to the tip of the puncture needle, and the needle cover surrounds the outer periphery of the puncture needle.

2. 2. The drug solution administration device according to claim 1, wherein the movement restriction mechanism includes a snap fit having an engaging claw as the restriction member, A drug solution administration device in which the engagement claw engages with an engagement object to restrict movement of the needle cover toward the base end, and the engagement claw disengages from the engagement object to allow movement of the needle cover toward the base end.

3. 3. The drug solution administration device according to claim 2, wherein the movement restriction mechanism has a second cylindrical body disposed inside the cylindrical body, A drug solution administration device in which the engagement claw of the snap fit engages with an engagement portion provided on the second cylindrical body during the pre-use stage and the removal stage, and is disengaged from the engagement portion and inserted into the second cylindrical body during the installation stage and the puncture stage.

4. A drug solution administration device as described in claim 3, wherein, in a pre-detachment stage for removing the puncture needle from the base portion after the removal stage, a force in the base direction is applied to the needle cover, causing the elastic member to contract, and the engaging claws of the snap fit are disengaged from the engaging portion of the second cylindrical body and inserted into the inside of the second cylindrical body, allowing the needle cover to move in the base direction.

5. 5. The drug solution administration device according to claim 4, wherein a force in the base direction is applied to the needle cover via a needle cap placed over the puncture needle, causing the elastic member to contract, and the needle cover to move in the base direction so that the puncture needle is enclosed within the needle cap.

6. 2. The drug solution administration device according to claim 1, wherein the movement restriction mechanism has a rotor as the restriction member, the rotor being rotatable about a central axis of the cylindrical body as a rotation center, the cylindrical body has a first cam portion and a cam groove adjacent to the first cam portion, the needle cover has a second cam portion at a base end, The rotor has a rib formed on an outer circumferential surface thereof and protruding radially outward, In the mounting step, the rotor rotates and the rib moves from the first cam portion to the second cam portion, When the force acting in the base direction on the needle cover is removed after the installation step, the elastic member expands, the rotor moves in the tip direction, and the rib engages with the second cam portion of the needle cover while positioned within the cam groove, causing the rib to push the needle cover in the base direction, in a drug solution administration device.

7. 7. The drug solution administration device according to claim 6, wherein in a pre-detachment stage for removing the puncture needle from the base portion after the removal stage, a force in a proximal direction is applied to the needle cover via a needle cap that covers the puncture needle, causing the elastic member to contract, and the rotor to move in the proximal direction and rotate, In a removal step of removing the needle cap and the puncture needle from the base portion, the elastic member stretches, causing the rotor and the needle cover to move toward the tip and the rotor to rotate, and the rib to move from the second cam portion to the first cam portion outside the cam groove.

8. The drug solution administration device according to claim 1 , wherein the puncture needle is contained in a needle cap, and in the attachment step, a force in the base end direction is applied to the needle cover via the needle cap.

9. A drug solution administration device as described in claim 1, wherein, in an initial stage before the puncture needle is attached to the base portion, the tip of the needle cover is located further forward than the tip of the base portion, and the needle cover surrounds the outer periphery of the base portion.

10. The drug solution administration device according to any one of claims 1 to 9, further comprising a grip that is detachably attached to a base end of the reservoir holder.

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