Medical liquid administration device

Abstract

A medical liquid administration device (10) comprises: a start signal generation part (110A) that generates a first signal for causing the start time when a medical liquid (M) is administered into a living body to be perceived; and a completion signal generation part (110B) that generates a second signal for causing the completion time when the administration of the medical liquid (M) is completed to be perceived. The start signal generation part (110A) has: an elastic structure (76) that is provided to a plunger (64) and that is elastically deformable in the radial direction; a first reduced diameter part (112A); and a first collision part (114A) that is provided further in the tip direction than the first reduced diameter part (112A) and can collide with the elastic structure (76). The completion signal generation part (110B) has: an elastic structure (76); a second reduced diameter part (112B) provided more in the tip direction than the first reduced diameter part (112A); and a second collision part (114B) provided further in the tip direction than the second reduced diameter part (112B) and can collide with the elastic structure (76).

Description

Medical solution administration device

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

[0002] Japanese Patent Publication No. 6154061 discloses a drug solution administration device. The drug solution administration device includes a cylindrical casing, a syringe housed inside the casing and filled with drug solution, and a cap removably attached to the tip of the casing. When a user uses the device, after removing the cap from the tip of the casing, the user presses the tip of the casing against the skin, causing a puncture needle to protrude from the tip of the casing, which then punctures the skin to administer the drug solution subcutaneously. After administration of the drug solution is complete, the user moves the tip of the casing away from the skin.

[0003] Patent No. 6154061

[0004] In the above-described medicinal liquid administration device, it is desirable that the user be able to recognize the start and end times of administration of the medicinal liquid.

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

[0006] (1) An aspect of the present disclosure is a drug solution administration device including: a housing; a cylindrical body accommodated in the housing and filled with a drug solution; a syringe having a puncture needle communicating with the cylindrical body and administering the drug solution into a living body; a trigger member that is displaced relative to the housing in a proximal direction by being pressed against a target to be punctured; a plunger that is provided inside the housing and is movable relative to the syringe in a distal direction in accordance with the relative displacement of the trigger member, and that ejects the drug solution from the puncture needle by moving in the distal direction; a start signal generating unit that generates a first signal that indicates a start time of administration of the drug solution into the living body; and a completion signal generating unit that generates a second signal that indicates a completion time of administration of the drug solution into the living body, wherein the start signal generating unit is provided on the plunger and has an elastic structure that is elastically deformable in a radial direction; a first reduced diameter portion that is provided radially outward of the plunger and protrudes radially inward toward the plunger; and a first reduced diameter portion that is provided distally of the first reduced diameter portion. and a first collision target portion, wherein as the plunger moves toward the tip direction of the housing, the elastic structure is pushed radially inward by the first reduced diameter portion and elastically deforms, and after the elastic structure passes the first reduced diameter portion, the elastic structure elastically restores radially outward and collides with the first collision target portion, thereby generating the first signal; and the completion signal generating portion has the elastic structure, a second reduced diameter portion that is provided radially outward of the plunger and protrudes radially inward toward the plunger, and is provided further toward the tip than the first collision target portion, and a second collision target that is provided further toward the tip than the second reduced diameter portion, wherein as the plunger moves toward the tip direction of the housing, the elastic structure is pushed radially inward by the second reduced diameter portion and elastically deforms, and after the elastic structure passes the second reduced diameter portion, the elastic structure elastically restores radially outward and collides with the second collision target portion, thereby generating the second signal.

[0007] This medicinal liquid administration device has a simple structure and allows the user to effectively recognize the start and end times of medicinal liquid administration.

[0008] (2) In the drug solution administration device described in (1) above, the plunger is biased toward the distal end direction by the resilient force of a spring provided inside the housing, and the elastic structure has a flexible portion extending along the axial direction of the plunger, a flange portion provided at the base end of the flexible portion and protruding radially outward from the flexible portion, and a rib provided in the distal end direction from the flange portion, extending along the outer surface of the flexible portion and protruding from the outer surface, and the plunger is biased toward the housing. In a state before the plunger moves in the distal direction, the flange portion and the base end of the first reduced diameter portion are held in contact with each other in the axial direction, the flange portion has an abutting portion that abuts against the base end of the first reduced diameter portion, the abutting portion and the rib are each tapered toward the distal direction of the plunger, an angle formed between the axial direction of the plunger and the abutting portion of the flange portion is defined as a first angle, and an angle formed between the axial direction of the plunger and an outer surface of the rib is defined as a second angle. the second angle is smaller than the first angle, and the housing includes a lock pin that is movably provided inside the housing and that can be inserted into the elastic structure to prevent the elastic structure from elastically deforming radially inward, the lock pin is movable in the base end direction by relative displacement of the trigger member in the base end direction, and when the lock pin moves in the base end direction from an elastic deformation prevented state in which the lock pin is inserted into the elastic structure and the elastic deformation of the elastic structure is prevented radially inward, the lock pin disengages from the interior of the elastic structure and the elastic deformation prevented state of the elastic structure is released, and the elastic structure elastically deforms radially inward, causing the plunger to move in the tip end direction, and the start signal generating unit generates the first signal when the flange collides with the first collision target, and the completion signal generating unit generates the second signal when the flange collides with the second collision target.

[0009] With this configuration, the second angle of the rib is smaller than the first angle of the flange, so that the elastic structure can overcome the second reduced diameter portion with a smaller elastic force than when the plunger starts to move.

[0010] (3) In the medicinal solution administration device described in (2) above, the rib may extend to the abutment portion of the flange portion, and the first reduced diameter portion may have a notch portion that accommodates the rib of the plunger.

[0011] With this configuration, by extending the rib up to the abutment portion of the flange, it is possible to prevent the flange and the second reduced diameter portion from coming into contact in the axial direction at the completion signal generating portion, making it easier for the flexible portion of the plunger to overcome the second reduced diameter portion. The cutout portion effectively prevents contact between the rib and the first reduced diameter portion when the plunger moves.

[0012] (4) In the drug solution administration device described in (2) or (3) above, the second reduced diameter portion may have two or more recessed portions that are recessed radially outward and extend in the axial direction of the housing, into which two or more of the ribs are inserted.

[0013] This configuration effectively prevents the plunger from shifting in a direction intersecting the direction of movement within the housing, thereby allowing the elastic structure to effectively collide with the second collision target.

[0014] (5) In the drug solution administration device described in (4) above, the second reduced diameter portion may have a base end inclined surface that inclines radially inward toward the tip of the housing, and a curved surface portion that connects the base end inclined surface and the recess portion.

[0015] With this configuration, when the plunger moves toward the tip, the base end inclined surface can effectively elastically deform the flange portion radially inward, and the curved surface portion can effectively guide the rib into the recess portion.

[0016] (6) In the drug solution administration device described in any one of (1) to (5) above, the tip end of the second reduced diameter portion may have a tip inclined surface that is inclined radially outward toward the base end.

[0017] With this configuration, when the flange portion overcomes the second reduced diameter portion and elastically restores its original shape, the tip inclined surface prevents contact between the flange portion and the second reduced diameter portion, thereby effectively preventing the flange portion's elastic restoring force in the radially outward direction from being reduced.

[0018] (7) In the drug solution administration device described in (1) above, the elastic structure may have a flexible portion extending along the axial direction of the plunger and a flange portion provided at the base end of the flexible portion and protruding radially outward from the flexible portion, and the start signal generating unit may generate the first signal when the flange portion collides with the first collision portion, and the completion signal generating unit may generate the second signal when the flange portion collides with the second collision portion.

[0019] With this configuration, the flange of the plunger is a part that is commonly used for generating the first signal and the second signal, thereby streamlining the structure.

[0020] (8) In the drug solution administration device described in any one of (2) to (6) above, the elastic structure may have two or more elastic pieces, and each of the two or more elastic pieces may be provided with a rib.

[0021] With this configuration, by bringing two or more ribs into contact with the second reduced diameter portion, the plunger can be moved toward the tip while aligning the axis of the plunger with the axis of the housing, causing the elastic structure to collide evenly and simultaneously with the second impact portion.

[0022] According to the present disclosure, the start signal generating unit generates a first signal that notifies the user of the start time of administration of the medicinal liquid into the living body, and the completion signal generating unit generates a second signal that notifies the user of the completion time of administration of the medicinal liquid. As the plunger moves toward the distal end, the elastic structure is pushed radially inward by the first reduced diameter portion, elastically deforms, and then collides with a first collision target of the housing, generating the first signal. As the plunger moves toward the distal end, the elastic structure is elastically deformed, and then collides with a second collision target, generating the second signal. This allows the user to effectively recognize the start time and completion time of administration of the medicinal liquid with a simple structure.

[0023] FIG. 1 is an external perspective view of a medicinal solution administration device according to an embodiment of the present disclosure. FIG. 2 is an overall cross-sectional view of the medicinal solution administration device of FIG. 1. FIG. 3 is an external perspective view of a sleeve body. FIG. 4 is an enlarged cross-sectional view of a start signal generating unit. FIG. 5 is an external perspective view of a plunger. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 4. FIG. 7A is a cross-sectional view taken along line VIIA-VIIA in FIG. 6. FIG. 7B is a cross-sectional view taken along line VIIB-VIIB in FIG. 6. FIG. 8 is an enlarged cross-sectional view of a completion signal generating unit. FIG. 9 is a first explanatory diagram illustrating the start signal generating unit when it is activated. FIG. 10 is a second explanatory diagram illustrating the start signal generating unit when it is activated. FIG. 11 is an external perspective view of an end guide. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 8. FIG. 13 is a first explanatory diagram illustrating the completion signal generating unit when it is activated. FIG. 14 is a second explanatory diagram illustrating the completion signal generating unit when it is activated. FIG. 15 is a first explanatory diagram illustrating the use of the medicinal solution administration device. Fig. 16 is a second explanatory diagram of how the drug solution administration device is used, Fig. 17 is a third explanatory diagram of how the drug solution administration device is used, and Fig. 18 is a fourth explanatory diagram of how the drug solution administration device is used.

[0024] As shown in Fig. 1, a medicinal solution administration device 10 according to this embodiment is used, for example, to administer a medicinal solution M subcutaneously to a user, that is, a patient K (living body). As shown in Fig. 2, the medicinal solution administration device 10 includes a hollow cylindrical housing 12, a trigger member 14 that is movable relative to the housing 12, and a syringe 16 housed inside the trigger member 14. Before use, the medicinal solution administration device 10 has a cap 18 attached to the tip of the housing 12. When using the medicinal solution administration device 10, the cap 18 can be removed from the housing 12 (see Fig. 15).

[0025] The housing 12 is made of a resin material and has a main body 20 extending axially (in the direction of arrows A and B), a sleeve body 22 housed at the base end side (in the direction of arrow A) of the main body 20, and an end cap 24 that closes the base end of the main body 20. The syringe 16 is housed inside the housing 12.

[0026] The main body 20 is cylindrical and elongated in the axial direction (the direction of arrows A and B). The distal end and proximal end of the main body 20 are both open. As shown in FIG. 1 , the peripheral wall of the main body 20 is provided with a window 26. The window 26 allows the medicinal liquid M in the syringe 16 to be observed from outside the housing 12.

[0027] 3, the sleeve body 22 is hollow and includes a cylindrical main body 30, an expanded diameter portion 32 formed at the base end of the main body 30, and a pair of body tip portions 33 protruding from the tip of the main body 30.

[0028] 2 , the main body 30 is provided with a plurality of guide ribs 34 inside. Each of the guide ribs 34 protrudes radially inward from the inner circumferential surface of the main body 30. Each of the guide ribs 34 extends along the axial direction of the sleeve body 22.

[0029] 3 , the outer peripheral surface of the body main body 30 is provided with a pair of locking grooves 36. The locking grooves 36 are recessed radially inward from the outer peripheral surface of the body main body 30. The locking grooves 36 extend along the axial direction of the body main body 30. The pair of locking grooves 36 are disposed at positions symmetrical with respect to the axial center of the sleeve body 22.

[0030] The body tip portion 33 includes a pair of sleeve claws 38. The pair of sleeve claws 38 protrude radially outward from the outer peripheral surface of the body main body 30. When viewed in the axial direction of the sleeve body 22, the pair of sleeve claws 38 are arranged symmetrically about the central axis of the body main body 30.

[0031] 2, the sleeve body 22 is housed inside the housing 12 (main body 20) from the base end of the main body 20. The expanded diameter portion 32 engages with the inner circumferential portion of the main body 20. The sleeve body 22 is fixed inside the housing 12 with the base end of the expanded diameter portion 32 positioned a predetermined distance from the base end of the main body 20 in the distal direction (direction of arrow B).

[0032] A sleeve spring 40 is disposed between the outer peripheral surface of the main body 30 and the inner peripheral surface of the housing 12. The sleeve spring 40 is a resilient member formed of a coil spring. The base end of the sleeve spring 40 is engaged with the tip of the expanded diameter portion 32. The tip end of the sleeve spring 40 is engaged with a slide member 56, which will be described later. The resilient force of the sleeve spring 40 urges the slide member 56 in a direction that separates the slide member 56 from the sleeve body 22, i.e., in the direction of arrow B.

[0033] The lock pin 44 is provided so as to be movable in the axial direction inside the housing 12 and the sleeve body 22. When the medical solution administration device 10 is in a state before use, the lock pin 44 is arranged so as to straddle the expanded diameter portion 32 and the main body 30 in the axial direction of the sleeve body 22. The lock pin 44 has a cylindrical pin main body 46 and a pair of arm portions 48 provided radially outward from the pin main body 46.

[0034] As shown in FIG. 4 , the pin body 46 is provided at the center of the lock pin 44. The pin body 46 has a hole 461. The hole 461 is formed inside the pin body 46. The hole 461 extends along the axial direction of the pin body 46. As shown in FIG. 2 , the base end of the pin body 46 is provided with an end wall 50. The end wall 50 is perpendicular to the axial direction of the pin body 46. The end wall 50 extends radially outward from the pin body 46. The hole 461 of the pin body 46 penetrates the end wall 50.

[0035] The pair of arm portions 48 are provided at the base end of the pin body 46. The pair of arm portions 48 are connected to the outer edge of the end wall portion 50. The pair of arm portions 48 extend from the end wall portion 50 toward the tip. The pair of arm portions 48 are arranged parallel to the pin body 46 and spaced apart radially outward from the pin body 46. The tip of the arm portion 48 has an engagement end 52 and a locking pawl (not shown). The locking pawl is engaged with the locking groove 36 (see FIG. 3 ) of the sleeve body 22. The locking pawl and the locking groove 36 are engaged with each other, thereby supporting the lock pin 44 movably along the axial direction of the sleeve body 22.

[0036] As shown in Figure 2, a slide member 56 is further provided inside the main body 20 of the housing 12. The slide member 56 is formed in a cylindrical shape. The slide member 56 is provided in the direction of the tip of the lock pin 44 (in the direction of arrow B). The slide member 56 is arranged inside the main body 20 of the housing 12 so as to be movable in the axial direction (in the directions of arrows A and B). The slide member 56 is provided radially outward from the sleeve body 22.

[0037] The slide member 56 has a cylindrical sleeve main body 561, a tubular portion 562 disposed at the tip of the sleeve main body 561, and a pair of engagement arms 563 extending from the base end of the sleeve main body 561. The main body 30 of the sleeve body 22 and the arm portion 48 of the lock pin 44 are inserted into the sleeve main body 561. The arm portion 48 is guided along the axial direction of the sleeve main body 561.

[0038] The pair of engagement arms 563 are arranged symmetrically about the axis of the slide member 56. Each engagement arm 563 protrudes toward the base end of the slide member 56. The engagement arms 563 have a slit hole 58. The slit hole 58 is formed along the extension direction of the engagement arm 563. The base end of the slit hole 58 has a protruding piece 60 that protrudes from the base end of the engagement arm 563 toward the tip. A part of the arm portion 48 of the lock pin 44 is inserted into the slit hole 58. The engagement end 52 of the lock pin 44 is engageable with the tip of the slit hole 58. The protruding portion of the arm portion 48 is engageable with the protruding piece 60. This engages the lock pin 44 with the slide member 56, preventing the lock pin 44 from coming off the slide member 56 in the base end direction.

[0039] The end guide 62 has a cylindrical portion 621 and is disposed toward the tip of the slide member 56. The end guide 62 and the slide member 56 are positioned relative to each other in the circumferential direction. A plunger 64 is inserted into the end guide 62 so as to be movable in the axial direction.

[0040] A pair of sleeve claws 38 (see FIG. 3 ) of the sleeve body 22 engage with the inner circumferential surface of the end guide 62. The engagement between the end guide 62 and the sleeve claws 38 positions the sleeve body 22 and the end guide 62 in the axial direction. Relative rotation between the sleeve body 22 and the end guide 62 is prevented. The tip of the end guide 62 abuts against a flange 92 of the syringe 16. The end guide 62 biases the syringe 16 toward the tip (direction of arrow B).

[0041] The end cap 24 is provided at the base end of the housing 12. The end cap 24 has a lid portion 66 and a shaft portion 68 extending from the lid portion 66 toward the tip (in the direction of arrow B). The lid portion 66 is formed in a disk shape. The lid portion 66 closes the base end of the main body 20.

[0042] The shaft portion 68 is a shaft body extending in the axial direction from the center of the lid portion 66. The shaft portion 68 is housed inside the main body 20 and the sleeve body 22. The shaft portion 68 is arranged on the axis of the main body 20. A portion of the shaft portion 68 is inserted into the hole portion 461 of the lock pin 44 and the inside of the plunger 64. An injection spring 70 is inserted around the outer periphery of the shaft portion 68. A portion of the injection spring 70 is housed inside the plunger 64 together with the shaft portion 68. The injection spring 70 is a coil spring. The injection spring 70 is interposed between the plunger 64 and the lid portion 66.

[0043] The plunger 64 has a cylindrical shape that is long in the axial direction (the direction of arrows A and B). The plunger 64 is housed inside the housing 12 and the sleeve body 22 so as to be able to move in the axial direction. As shown in FIG. 5 , the plunger 64 includes a cylindrical rod main body 72, a mounting portion 74 formed at the tip of the rod main body 72, and an elastic structure 76 that is elastically deformable in the radial direction. As shown in FIG. 2 , the plunger 64 is disposed coaxially with the sleeve body 22 and the end guide 62. The plunger 64 is urged toward the tip (the direction of arrow B) by the elastic force of the injection spring 70.

[0044] A plurality of slide grooves 78 are formed on the outer peripheral surface of the rod main body 72. The plurality of slide grooves 78 are recessed radially inward relative to the outer peripheral surface of the rod main body 72. The guide ribs 34 of the sleeve body 22 are inserted into each slide groove 78. When the plunger 64 is housed inside the sleeve body 22, the radially inner ends of the guide ribs 34 are inserted into the respective slide grooves 78.

[0045] 4, the rod body 72 has a rod hole 80 formed therein. The rod hole 80 extends along the axial direction (the direction of arrows A and B) of the rod body 72. The shaft portion 68 of the end cap 24, the injection spring 70, and the pin body 46 of the lock pin 44 are inserted into the rod hole 80.

[0046] The elastic structure 76 has elasticity that allows it to elastically deform radially inward and elastically recover radially outward. Before use of the drug solution administration device 10, the pin body 46 of the lock pin 44 is inserted into the elastic structure 76. As shown in FIG. 5 , the elastic structure 76 includes a plurality of elastic pieces 760.

[0047] Each elastic piece 760 has a flexible portion 761, a flange portion 762, and a rib 763. Therefore, the elastic structure 76 includes a plurality of flexible portions 761, a plurality of flange portions 762, and a plurality of ribs 763.

[0048] The multiple flexible portions 761 are formed at the base end of the rod main body 72 and are divided in the circumferential direction. Each of the multiple flexible portions 761 extends along the axial direction of the plunger 64. As shown in FIG. 6 , the multiple flexible portions 761 are formed to have the same shape. The multiple flexible portions 761 are arc-shaped and are spaced equally apart in the circumferential direction around the central axis of the plunger 64. Below, a case will be described in which the elastic structure 76 includes four flexible portions 761, four flange portions 762, and four ribs 763.

[0049] As shown in Fig. 5, the flexible portions 761 protrude in the axial direction (the direction of arrow A) from the base end of the rod main body 72 and are arranged so as to be spaced apart from each other in the circumferential direction. As shown in Fig. 7A, the flexible portions 761 expand radially outward toward the base end relative to the rod main body 72. The flexible portions 761 are arranged between two adjacent slide grooves 78 (see Fig. 5). The base ends (free ends) of the flexible portions 761 can be displaced radially inward, with the tip ends (fixed ends) of the flexible portions 761 connected to the rod main body 72 serving as a fulcrum. That is, each of the multiple flexible portions 761 can elastically deform radially inward.

[0050] As shown in Figure 4, the pin body 46 of the lock pin 44 is inserted into the flexible portion 761. The inner diameter of the elastic structure 76, which is composed of multiple elastic pieces 760, is larger than the inner diameter of the rod hole 80. By inserting the pin body 46 into the elastic structure 76, elastic deformation in the radially inward direction of the flexible portion 761 is prevented. Before use of the medicinal solution administration device 10, by inserting the pin body 46 of the lock pin 44 into the interior of each elastic piece 760, an elastic deformation-prevented state is achieved in which elastic deformation in the radial direction of each elastic piece 760 is prevented.

[0051] An engagement step 82 is provided at the boundary between the flexible portion 761 and the rod body 72. The engagement step 82 extends in a radial direction perpendicular to the axial direction of the plunger 64. When the pin body 46 of the lock pin 44 is inserted into the rod hole 80, the tip of the pin body 46 engages with the engagement step 82. This positions the plunger 64 in the axial direction relative to the lock pin 44.

[0052] The flange 762 is provided at the base end of the flexible portion 761 and protrudes radially outward from the flexible portion 761. The flange 762 is provided on each of the multiple flexible portions 761. That is, there are the same number of flanges 762 as flexible portions 761 (four in this embodiment). The flange 762 has an abutment portion 84 provided in the distal direction (direction of arrow B) of the flange 762. The abutment portion 84 extends in the radial direction of the plunger 64. The abutment portion 84 is a tapered surface that is inclined radially inward toward the distal direction (direction of arrow B). Before use of the medicinal solution administration device 10, the abutment portion 84 of the flange 762 abuts against the base end of the first reduced diameter portion 112A.

[0053] 7A , the angle formed between the axial direction of the plunger 64 and the abutment portion 84 of the flange portion 762 is a first angle θ1. The first angle θ1 is, for example, within a range of 60° to 89°. The first angle θ1 may be within a range of 75° to 85°. Furthermore, the first angle θ1 may be within a range of 78° to 82°.

[0054] 5, a plurality of ribs 763 are formed on the outer surfaces of the plurality of flexible portions 761. The number of ribs 763 is the same as the number of flange portions 762 and flexible portions 761 (four in this embodiment). Note that the number of ribs 763 may differ from the number of flange portions 762 and flexible portions 761.

[0055] Each rib 763 is provided on the plunger 64 distally of each flange 762. Each of the ribs 763 extends axially along the outer surface of the flexible portion 761. Each of the ribs 763 protrudes radially outward from the outer surface of the flexible portion 761. The height of each rib 763 in the radial direction of the plunger 64 gradually increases from the tip of the flexible portion 761 toward the flange 762. Each rib 763 tapers from the flange 762 toward the distal end (the direction of arrow B). The base end of the rib 763 is connected to the abutment portion 84 of the flange 762. In the radial direction of the plunger 64, the height of the base end of each rib 763 and the height of the outer surface of the flange 762 are approximately the same. In the circumferential direction of the plunger 64, each rib 763 is disposed at the circumferential center of the corresponding flange 762 (see FIG. 6 ).

[0056] As shown in FIG. 7B , the angle formed between the axial direction of the plunger 64 and the outer surface of the rib 763 is a second angle θ2. The second angle θ2 is smaller than the first angle θ1 (θ2<θ1). The second angle θ2 is, for example, in the range of 1° to 30°. The second angle θ2 may be in the range of 5° to 15°. Furthermore, the second angle θ2 may be in the range of 7° to 10°.

[0057] The elastic structure 76 may have a first elastic piece that generates the first signal and a second elastic piece that generates the second signal. In this case, the first elastic piece does not have the rib 763. The second elastic piece does not contact the first reduced diameter portion 112A. Furthermore, the first elastic piece and the second elastic piece may be provided at different positions in the axial direction of the plunger 64.

[0058] As shown in Figure 2, the mounting portion 74 has a smaller diameter than the rod main body 72. The tip of the injection spring 70 engages with the boundary between the mounting portion 74 and the rod main body 72. As a result, the resilient force of the injection spring 70 urges the plunger 64 in a direction that moves it away from the end cap 24, i.e., toward the tip (direction of arrow B). A top member 86 is attached to the tip of the mounting portion 74. The top member 86 is cylindrical and protrudes from the tip of the plunger 64 toward the tip.

[0059] The trigger member 14 is pressed against the skin S (the target to be punctured) of the patient K, and is displaced relative to the housing 12 in the proximal direction (direction of arrow A). The trigger member 14 is movably arranged inside the main body 20 of the housing 12. The trigger member 14 is configured as a needle cover that covers the puncture needle 164, which will be described later.

[0060] The trigger member 14 includes a cylindrical trigger body 141, a pair of cover portions 142 extending from the trigger body 141 in the proximal direction (the direction of arrow A), and a pair of extension portions 143 extending from the proximal end of the cover portions 142. The resilient force of the sleeve spring 40 is biased toward the distal end of the trigger member 14 via the slide member 56. Before use of the medicinal solution administration device 10, the distal end of the trigger member 14 protrudes distally (the direction of arrow B) beyond the distal end of the housing 12.

[0061] The trigger body 141 is formed at the tip end (in the direction of arrow B) of the trigger member 14. The trigger body 141 includes a hole 14a and a pair of engagement holes 88. The hole 14a is formed at the center of the tip end of the trigger body 141 and opens through in the axial direction. The pair of engagement holes 88 are formed on the outer surface of the trigger body 141. Each of the pair of engagement holes 88 penetrates the trigger body 141 in the radial direction.

[0062] The pair of cover portions 142 are arranged symmetrically about the axis of the trigger member 14, and each extends along the axial direction. Each of the pair of cover portions 142 has a syringe guide hole 90. The syringe guide hole 90 penetrates the cover portion 142 in the radial direction and extends in the axial direction. The syringe guide hole 90 is provided further proximally than the engagement hole 88. The syringe guide hole 90 and the engagement hole 88 are arranged in a straight line along the axial direction of the trigger member 14. The extension portion 143 extends further proximally from the proximal end of the cover portion 142. The proximal end of the extension portion 143 is connected to the tip of the tubular portion 562 of the slide member 56.

[0063] The syringe 16 includes a hollow cylindrical body 161 , a stopper 163 , a puncture needle 164 , and a protective cover 165 .

[0064] The cylindrical body 161 is made of a transparent resin material. The cylindrical body 161 is a hollow body formed in a substantially cylindrical shape with an open base end. The interior of the cylindrical body 161 is provided with a chamber 162 filled with a medicinal solution M. The outer periphery of the base end of the cylindrical body 161 is provided with a flange 92 that protrudes radially outward. The tip of the cylindrical body 161 is provided with a needle holding portion 94. The needle holding portion 94 has a reduced diameter from the cylindrical body 161 and protrudes toward the tip. The needle holding portion 94 holds the base end of the puncture needle 164. Note that the medicinal solution M may be, for example, one used for subcutaneous injections by a user.

[0065] The stopper 163 is slidably inserted into the interior of the cylindrical body 161. The stopper 163 is made of an elastic material such as rubber. The stopper 163 is attached to the tip of the top member 86. The stopper 163 protrudes in the tip direction relative to the top member 86. The stopper 163 is inserted into the chamber 162 of the cylindrical body 161 through the base end opening of the cylindrical body 161. The stopper 163 is housed along the chamber 162 of the cylindrical body 161 so as to be slidable in the axial direction. By inserting the stopper 163 into the interior of the cylindrical body 161, the base end side of the cylindrical body 161 is sealed liquid-tight, and the medicinal solution M in the chamber 162 is enclosed inside the cylindrical body 161.

[0066] The puncture needle 164 is provided in the needle holding portion 94 of the cylindrical body 161 and protrudes from the needle holding portion 94 toward the distal end (in the direction of arrow B). The puncture needle 164 is a hollow body having an internal flow path through which the medicinal liquid M flows. The flow path of the puncture needle 164 communicates with the interior of the cylindrical body 161 which is filled with the medicinal liquid M. When the plunger 64 moves toward the distal end, the stopper 163 causes the medicinal liquid M in the medicine chamber 162 to be ejected from the tip of the puncture needle 164 and administered to the patient K (see FIG. 15 ).

[0067] The protective cover 165 is attached to the tip of the cylindrical body 161 and covers the puncture needle 164. The protective cover 165 is attached to the needle holder 94 so as to cover the puncture needle 164.

[0068] The syringe holder 96 is formed in a cylindrical shape and is provided on the outer periphery of the syringe 16. The syringe holder 96 holds the cylindrical body 161 of the syringe 16.

[0069] The syringe holder 96 includes a holder main body 961 and a pair of guide portions 962 that protrude radially outward from the outer peripheral surface of the holder main body 961. The holder main body 961 is formed in a cylindrical shape and is held on the inner peripheral surface of the housing 12. The holder main body 961 accommodates the cylindrical body 161 of the syringe 16. The base end of the syringe holder 96 is engaged with the flange 92 of the syringe 16.

[0070] The guide portion 962 is inserted into the syringe guide hole 90 of the trigger member 14. The syringe holder 96 is held together with the syringe 16 inside the trigger member 14 so as to be movable along the axial direction (direction of arrows A and B).

[0071] When the syringe 16 is held in the syringe holder 96 and housed inside the trigger member 14, the puncture needle 164 is positioned toward the tip (in the direction of arrow B), and the cylindrical body 161 faces the window portion 26 of the housing 12 (see Figure 1).

[0072] The cap 18 is formed in a cylindrical shape with a bottom, and has a bottom wall 981 and an annular peripheral wall 982. The bottom wall 981 is formed at the tip of the cap 18. The peripheral wall 982 extends from the bottom wall 981 toward the base end (direction of arrow A). The base end of the cap 18 is open. The cap 18 further has a pair of holding arms 100. The pair of holding arms 100 protrude in the axial direction (direction of arrow A) from the base end of the peripheral wall 982. The holding arms 100 are disposed radially inward with respect to the peripheral wall 982 and can tilt radially outward with the connection point with the peripheral wall 982 as a fulcrum. The base end of the holding arm 100 is provided with a hook 102 protruding radially inward.

[0073] When the cap 18 is attached to the tip of the main body 20 of the drug solution administration device 10 before use, the hooks 102 of the pair of holding arms 100 are inserted into a pair of recesses 104 formed in the inner circumferential surface of the housing 12, respectively. The recesses 104 are recessed radially outward from the inner circumferential surface of the main body 20. With the cap 18 positioned axially relative to the housing 12, the cap 18 is fixed to the tip of the housing 12. In this way, the cap 18 is attached so as to cover the trigger member 14 and the tip of the housing 12.

[0074] The chemical solution administration device 10 further includes a start signal generating unit 110A (see FIG. 4) and a completion signal generating unit 110B (see FIG. 8).

[0075] 4, the start signal generating unit 110A generates a first signal that notifies the patient K of the start time of subcutaneous administration of the medicinal solution M as the plunger 64 moves toward the tip. The start signal generating unit 110A is composed of an elastic structure 76 provided on the plunger 64, and a first reduced diameter portion 112A and a first collision receiving portion 114A provided inside the housing 12.

[0076] A plurality of first reduced diameter portions 112A are provided on the inner circumferential surface of the sleeve body 22 and are provided radially outward of the plunger 64. The plurality of first reduced diameter portions 112A are provided at the boundary between the expanded diameter portion 32 of the sleeve body 22 and the main body 30. As shown in Fig. 6, the plurality of first reduced diameter portions 112A protrude radially inward from the inner circumferential surface of the sleeve body 22. The number of first reduced diameter portions 112A is the same as the number of flexible portions 761 of the plunger 64 (four in this embodiment).

[0077] The first reduced diameter portions 112A and the flexible portions 761 are disposed at the same position in the circumferential direction of the sleeve body 22. When viewed in the axial direction of the sleeve body 22, each first reduced diameter portion 112A has an arc shape, and each of the plurality of flange portions 762 and each of the plurality of first reduced diameter portions 112A are disposed linearly. The number of first reduced diameter portions 112A may be an even number.

[0078] The first reduced diameter portion 112A has a first surface 116A disposed radially inward. The first surface 116A is substantially parallel to the axial direction of the sleeve body 22. A diameter D11 of the first surface 116A is smaller than the outer diameter d (see FIG. 7A ) of the flange portion 762 of the plunger 64 (D11<d).

[0079] Before use of the medicinal solution administration device 10, the abutment portion 84 of the flange 762 of the plunger 64 abuts against and engages with the base end side (direction of arrow A) of the first reduced diameter portion 112A. As the plunger 64 moves toward the distal end of the housing 12, the outer surface of the flange 762 of the plunger 64 can come into contact with the first surface 116A of the first reduced diameter portion 112A. The first reduced diameter portion 112A presses each of the plurality of flanges 762 radially inward. Pressing each flange 762 elastically deforms each flexible portion 761 radially inward.

[0080] As shown in FIG. 6 , each of the first reduced diameter portions 112A includes a notch 118. The notch 118 is recessed radially outward from the first surface 116A of the first reduced diameter portion 112A. The notch 118 is located at the circumferential center of each first reduced diameter portion 112A. That is, each first reduced diameter portion 112A is divided into two by the notch 118 in the circumferential direction of the sleeve body 22. The notch 118 penetrates the first reduced diameter portion 112A in the axial direction of the sleeve body 22 (see FIG. 3 ). When viewed from the axial direction of the sleeve body 22, the notch 118 has a substantially rectangular shape. The rib 763 of the plunger 64 is accommodated in the notch 118. When the plunger 64 moves toward the distal end, the rib 763 passes through the notch 118. Note that the first reduced diameter portion 112A is not limited to having the notch 118. For example, if the rib 763 is disposed radially inward from the first surface 116A of the first reduced diameter portion 112A, the notch 118 is not necessary.

[0081] As shown in FIG. 4 , the first collision receiving portion 114A is provided on the inner circumferential surface of the main body 30 of the sleeve body 22. The first collision receiving portion 114A is disposed distally of the first reduced diameter portion 112A (in the direction of arrow B) and adjacent to the first reduced diameter portion 112A. The first collision receiving portion 114A is disposed radially outward of the first surface 116A of the first reduced diameter portion 112A. As shown in FIG. 10 , the first collision receiving portion 114A can collide with the elastic structure 76 when the plunger 64 moves distally. The first collision receiving portion 114A and the first reduced diameter portion 112A are disposed linearly in the axial direction of the sleeve body 22. As shown in FIG. 4 , the diameter D12 of the first collision receiving portion 114A is larger than the diameter D11 of the first surface 116A of the first reduced diameter portion 112A and is equal to or smaller than the outer diameter d of the flange portion 762 (see FIG. 7A ).

[0082] After the plunger 64 moves distally and the flange 762 passes through the first reduced diameter portion 112A, the flexible portion 761 and the flange 762 can elastically return to their original position radially outward, as shown in Fig. 10. The outer peripheral surface of each flange 762 that has returned to its original position collides radially with the first collision target portion 114A. The collision between each flange 762 and the first collision target portion 114A generates a first signal.

[0083] The first signal is a collision sound generated when the flange 762 of the plunger 64 and the first collision target 114A collide. Note that the first signal is not limited to a collision sound. For example, the first signal may be a vibration generated when the flange 762 of the plunger 64 and the first collision target 114A collide. The first signal may be both a collision sound and a vibration. The first signal is a signal for notifying the administration start time when, in a state in which the puncture needle 164 of the medicinal solution administration device 10 has been inserted, the plunger 64 begins to move toward the tip, and the movement of the plunger 64 presses the stopper 163, thereby starting to administer the medicinal solution M in the syringe 16. The administration start timing is either before the medicinal liquid M is administered (before the medicinal liquid M starts to come out through the puncture needle 164), simultaneously with the start of administration of the medicinal liquid M (simultaneous with the start of administration of the medicinal liquid M through the puncture needle 164), or after administration of the medicinal liquid M has started (after the medicinal liquid M starts to come out through the puncture needle 164). That is, the start signal generating unit 110A generates a first signal when the flange portion 762 of the elastic structure 76 collides with the first collision target portion 114A.

[0084] 8, the completion signal generating unit 110B generates a second signal that notifies the patient K of the completion of the subcutaneous administration of the medicinal solution M as the plunger 64 moves toward the distal end. The completion signal generating unit 110B is composed of an elastic structure 76 provided on the plunger 64, and a second reduced diameter portion 112B and a second collision receiving portion 114B provided inside the housing 12.

[0085] As shown in FIG. 11 , multiple second reduced diameter portions 112B are provided on the inner circumferential surface of the end guide 62 and are provided radially outward of the plunger 64 (see FIG. 8 ). As shown in FIG. 8 , the second reduced diameter portions 112B are provided distally (in the direction of arrow B) from the first reduced diameter portions 112A. As shown in FIG. 12 , the multiple second reduced diameter portions 112B protrude radially inward from the inner circumferential surface of the cylindrical portion 621. The number of second reduced diameter portions 112B is the same as the number of flexible portions 761 of the plunger 64 (four in this embodiment). The second reduced diameter portions 112B and the flexible portions 761 are positioned at the same circumferential position of the end guide 62. When viewed in the axial direction of the end guide 62, the multiple second reduced diameter portions 112B and the ribs 763 of the plunger 64 face each other radially. The number of second reduced diameter portions 112B may be an even number.

[0086] As shown in FIG. 8, the second reduced diameter portion 112B includes a second surface 116B that can come into contact with the elastic structure 76, a recessed portion 120 recessed from the second surface 116B, and a tip inclined surface 124.

[0087] The second surface 116B includes a contact portion 126 (see FIG. 11 ) disposed radially inward, a base end inclined surface 128 provided at the base end of the contact portion 126, and a curved surface portion 130. The contact portion 126 is formed substantially parallel to the axial direction of the end guide 62. The diameter D21 of the contact portion 126 (second surface 116B) is smaller than the outer diameter d of the flange portion 762 of the plunger 64. The base end inclined surface 128 inclines radially inward from the base end of the cylindrical portion 621 of the end guide 62 toward the contact portion 126. Note that the second reduced diameter portion 112B is not limited to including the base end inclined surface 128. For example, the tip of the second reduced diameter portion 112B may be a horizontal surface perpendicular to the axial direction of the end guide 62.

[0088] The angle formed between the axial direction of the end guide 62 and the proximal inclined surface 128 is a third angle θ3. The third angle θ3 is, for example, within a range of 10° to 45°. The third angle θ3 may be within a range of 25° to 37°. Furthermore, the third angle θ3 may be within a range of 29° to 33°.

[0089] As shown in FIG. 12 , a recess 120 is provided in the center of the contact portion 126 in the circumferential direction of the end guide 62. The recess 120 extends in the axial direction of the end guide 62 (see FIG. 11 ). When viewed in the axial direction of the end guide 62, the recess 120 has an arc-shaped cross section recessed radially outward. The ribs 763 of the plunger 64 are inserted into the recesses 120. That is, the number of recesses 120 is the same as the number of ribs 763, i.e., multiple recesses. Inserting the ribs 763 of the plunger 64 into the recesses 120 prevents relative movement between the end guide 62 and the plunger 64 in the circumferential direction. The recesses 120 and the ribs 763 position the end guide 62 and the plunger 64 in the circumferential direction. Note that the second reduced diameter portion 112B is not limited to having the recess 120. For example, the recessed portion 120 may not be provided, and the rib 763 of the elastic structure 76 may be brought into direct contact with the contact portion 126 of the second surface 116B.

[0090] 11 , the curved surface portion 130 connects the recessed portion 120 and the proximal inclined surface 128. The curved surface portion 130 connects the proximal end of the recessed portion 120 and the distal end of the proximal inclined surface 128.

[0091] As shown in FIG. 8 , the distal inclined surface 124 is a surface provided at the distal end of the second reduced diameter portion 112B. The distal inclined surface 124 is inclined radially outward from the distal end of the second surface 116B toward the proximal end (the direction of arrow A). The angle formed between the axial direction of the end guide 62 and the distal inclined surface 124 is a fourth angle θ4. The fourth angle θ4 is, for example, within a range of 45° to 89°. The fourth angle θ4 may be within a range of 65° to 75°. Furthermore, the fourth angle θ4 may be within a range of 68° to 72°. Alternatively, instead of providing the distal inclined surface 124, a horizontal surface extending radially outward perpendicular to the axial direction of the end guide 62 may be provided at the distal end of the second reduced diameter portion 112B.

[0092] The second collision receiving portion 114B is provided on the inner circumferential surface of the cylindrical portion 621 of the end guide 62. The second collision receiving portion 114B is disposed toward the tip of the second reduced diameter portion 112B (in the direction of arrow B) and adjacent to the second reduced diameter portion 112B. The second collision receiving portion 114B is disposed radially outward of the second surface 116B of the second reduced diameter portion 112B. As shown in FIG. 14 , the second collision receiving portion 114B can collide with the elastic structure 76 when the plunger 64 moves toward the tip. The second collision receiving portion 114B and the second reduced diameter portion 112B are disposed linearly in the axial direction of the end guide 62. The diameter D22 of the second collision receiving portion 114B is larger than the diameter D21 of the second surface 116B of the second reduced diameter portion 112B and is equal to or smaller than the outer diameter d of the flange portion 762 (see FIG. 7A ).

[0093] As the plunger 64 moves toward the tip of the housing 12, each of the flanges 762 comes into contact with the second surface 116B of the second reduced diameter portion 112B. As shown in Fig. 13 , the second reduced diameter portion 112B presses each of the flanges 762 radially inward, causing each of the flexible portions 761 to elastically deform radially inward.

[0094] 14 , after the plunger 64 moves distally and the flange 762 passes through the second reduced diameter portion 112B, the flexible portion 761 and the flange 762 can elastically return to their original position radially outward. The outer peripheral surface of each flange 762 that has returned to its original position collides radially with the second collision target portion 114B. The collision between each flange 762 and the second collision target portion 114B generates a second signal.

[0095] The second signal is a collision sound generated when the flange 762 of the plunger 64 and the second collision target 114B collide. Note that the second signal is not limited to a collision sound. For example, the second signal may be a vibration generated when the flange 762 of the plunger 64 and the second collision target 114B collide. The second signal may be both a collision sound and a vibration. The second signal is a signal for notifying the administration completion time when, in a state in which the puncture needle 164 of the medicinal solution administration device 10 has been inserted, the plunger 64 begins to move toward the tip, and the movement of the plunger 64 presses the stopper 163, thereby completing the administration of the medicinal solution M in the syringe 16.

[0096] The administration completion timing is either before the administration of the medicinal liquid M is completed (before the medicinal liquid M finishes flowing through the puncture needle 164) or simultaneously with the completion of the administration of the medicinal liquid M (simultaneous with the medicinal liquid M finishing flowing through the puncture needle 164). That is, the completion signal generating unit 110B generates a second signal when the flange portion 762 of the elastic structure 76 collides with the second collision target portion 114B.

[0097] The elastic structure 76 of the start signal generating section 110A and the elastic structure 76 of the completion signal generating section 110B are not limited to being a common structure provided on the plunger 64.

[0098] Next, administration of the medicinal liquid M by the medicinal liquid administration device 10 will be described.

[0099] First, in the drug solution administration device 10 before use shown in Figure 2, the cap 18 is removed from the housing 12 and the tip of the trigger member 14. At this time, the user grasps the main body 20 of the housing 12 and pulls the cap 18 in a direction (indicated by arrow B) that moves the cap 18 away from the housing 12. This moves the cap 18 away from the tip of the trigger member 14, tilting the holding arm 100 and disengaging the hook 102 from the engagement hole 88. The protective cover 165 moves toward the tip together with the cap 18, thereby opening the housing 12 and the tip of the trigger member 14, and simultaneously removing the protective cover 165 that had been covering the puncture needle 164 (see Figure 15).

[0100] Next, the medicinal liquid M is administered using the medicinal liquid administration device 10 with the cap 18 removed.

[0101] As shown in Figure 15, in the state before puncturing of the medicinal solution administration device 10, the pin body 46 of the lock pin 44 is inserted inside the flexible portion 761 of the plunger 64 (see Figure 4). The lock pin 44 prevents the flexible portion 761 from tilting radially inward (elastic deformation). That is, the lock pin 44 prevents the elastic structure 76 from elastically deforming radially inward. That is, the flexible portion 761 cannot elastically deform radially inward. Because the flange portion 762 of the flexible portion 761 is engaged with the first reduced diameter portion 112A of the sleeve body 22, the plunger 64 cannot move distally.

[0102] The user grasps the housing 12 and presses the tip of the trigger member 14, which protrudes from the tip of the housing 12, against the skin S of the patient K, which will be the desired puncture site, at a substantially right angle. Next, the user continues to press the housing 12 further toward the skin S (toward the tip, in the direction of arrow B). As the housing 12 is pressed toward the skin S, the trigger member 14 is pressed by the skin S and moves relative to the housing 12 in the proximal direction (in the direction of arrow A) against the elastic force of the sleeve spring 40.

[0103] 16 , as the housing 12 is further pushed toward the skin S, the puncture needle 164 of the syringe 16 protrudes from the hole 14a of the trigger member 14 toward the tip (in the direction of arrow B). This causes the puncture needle 164 to puncture the skin S and enter a puncture-completed state in which it has been inserted to a predetermined depth. In the puncture-completed state, the tip of the main body 20 is at approximately the same position as the tip of the trigger member 14 in the axial direction of the medicinal solution administration device 10.

[0104] The trigger rib 144 of the trigger member 14 abuts against the tip of the slide member 56. Therefore, when the trigger member 14 moves in the proximal direction relative to the housing 12 as described above, the slide member 56 also moves in the proximal direction relative to the housing 12. As the slide member 56 moves in the proximal direction, the tip of the slit hole 58 of the slide member 56 pushes the engagement end 52 provided at the tip of the arm portion 48 of the lock pin 44 in the proximal direction, so that the lock pin 44 also moves in the proximal direction relative to the housing 12.

[0105] 16 , as the lock pin 44 moves relative to the housing 12 in the proximal direction (the direction of arrow A), the pin body 46 of the lock pin 44 moves away from the inside of the flexible portion 761 of the plunger 64 in the proximal direction (the direction of arrow A). This releases the locked state of the plunger 64 by the lock pin 44, and the four flexible portions 761 of the plunger 64 become tiltable radially inward.

[0106] When the plunger 64 begins to move toward the distal end (in the direction of arrow B) due to the elastic force of the injection spring 70, the abutment portions 84 of the four flanges 762 come into contact with the first reduced diameter portions 112A and are pushed radially inward. In this case, the ribs 763 of each flexible portion 761 are housed in the cutouts 118, so that the ribs 763 and the first reduced diameter portions 112A are not in contact. As a result, the abutment portions 84 of each flexible portion 761 begin to elastically deform radially inward from the base ends of the first reduced diameter portions 112A to overcome the first reduced diameter portions 112A, and each flexible portion 761 begins to tilt radially inward. As the plunger 64 further moves toward the distal end, as shown in FIG. 9 , the outer surfaces of the flanges 762 come into contact with the first surfaces 116A of the first reduced diameter portions 112A, causing the plunger 64 to move toward the distal end while elastically deforming radially inward. At this time, the four flange portions 762 simultaneously come into contact with the first surfaces 116A of the four first reduced diameter portions 112A, respectively.

[0107] After the plunger 64 moves further distally and the four flanges 762 overcome the first reduced diameter portion 112A, the flexible portion 761 again expands radially outward due to the elastic restoring force thereof, causing the outer surfaces of the flanges 762 to collide with the first collision target portion 114A, as shown in Fig. 10. At this time, the outer diameter d of the flanges 762 is larger than the diameter D11 of the first reduced diameter portion 112A and larger than the diameter D12 of the first collision target portion 114A, so that a first signal, which is a collision sound (smacking sound), is generated when the flanges 762 collide with the first collision target portion 114A. At this time, because the plunger 64 and the sleeve body 22 are positioned simultaneously, the four flanges 762 each collide with the first collision target portion 114A at approximately the same time, generating a collision sound. That is, the four flanges 762 generate a collision sound (first signal) once in the first collision receiving portion 114A.

[0108] After the plunger 64 starts moving toward the distal end and the flange 762 passes over the first reduced diameter portion 112A, the plunger 64 continues to move toward the distal end, causing the plunger 64 to start pushing the stopper 163. The medicinal solution M inside the cylindrical body 161 is pressed toward the distal end by the stopper 163. This causes the medicinal solution M to be expelled from the puncture needle 164, commencing subcutaneous administration of the medicinal solution M to the patient K. As described above, when the plunger 64 starts moving toward the distal end and the flange 762 passes over the first reduced diameter portion 112A, a first signal is generated as the flange 762 collides with the main body 30. By checking the first signal, the patient K can confirm the administration start time when administration of the medicinal solution M has begun. In this case, the administration start time occurs after a predetermined time has elapsed since administration of the medicinal solution M was initiated.

[0109] As the plunger 64 moves toward the distal end, it is guided by the guide ribs 34 of the sleeve body 22 inserted into the four slide grooves 78. As a result, when the plunger 64 moves toward the distal end, it moves only in the axial direction without rotating. The stopper 163 attached to the top member 86 is inserted into the cylindrical body 161 of the syringe 16.

[0110] After the administration of the medicinal solution M has begun, the plunger 64 continues to move continuously toward the distal end (in the direction of arrow B) at a constant speed due to the elastic force of the injection spring 70. The medicinal solution M is pushed out by the stopper 163 moving toward the distal end within the cylindrical body 161, and the medicinal solution M is discharged from the puncture needle 164. As the plunger 64 continues to move toward the distal end, as shown in FIG. 8 , the ribs 763 of the four flexible portions 761 come into contact with the proximal inclined surfaces 128 of the second reduced diameter portion 112B, and the four flexible portions 761 are gradually pushed radially inward by the proximal inclined surfaces 128 and elastically deformed.

[0111] As the plunger 64 moves further toward the distal end, the ribs 763 of each flexible portion 761 move while contacting the recessed portions 120, and after the base ends of the ribs 763 reach the second surfaces 116B of the second reduced diameter portions 112B, the flange portions 762 come into contact with the second surfaces 116B, as shown in Fig. 13. The contact portions 126 of the second reduced diameter portions 112B push the four flange portions 762 radially inward, causing the flexible portions 761 to elastically deform, and the plunger 64 moves toward the distal end. At this time, each of the four flange portions 762 simultaneously contacts the second surfaces 116B of the four second reduced diameter portions 112B.

[0112] As the plunger 64 moves distally, the four flanges 762 move distally and substantially simultaneously overpass the second reduced diameter portion 112B. After clearing the second reduced diameter portion 112B, the four flanges 762 are again expanded radially outward by the elastic restoring force of the flexible portion 761, and the outer surfaces of the flanges 762 collide with the second collision target portion 114B, as shown in FIG. 14 . At this time, because the outer diameter d of the flanges 762 is larger than the diameter D22 of the second collision target portion 114B, a second signal, which is a collision sound (smacking sound), is generated when the flanges 762 collide with the second collision target portion 114B. At this time, because the plunger 64 and the end guide 62 are positioned simultaneously, the four flanges 762 each collide with the second collision target portion 114B substantially simultaneously, generating a collision sound. That is, the four flanges 762 generate a collision sound (second signal) once in the second collision receiving portion 114B.

[0113] As described above, when plunger 64 moves distally and flange 762 passes over second reduced diameter portion 112B, flange 762 collides with second collision receiving portion 114B, generating a second signal. By checking the second signal, the user can confirm that the administration completion time for completing administration of medicinal solution M has arrived. In this case, as shown in FIG. 17 , the administration completion time occurs a predetermined time before the completion of administration of medicinal solution M.

[0114] The timing of generation of the second signal is immediately before the completion of administration of the medicinal liquid M. The timing of generation of the second signal is, for example, 0.5 to 1.0 seconds before the completion of administration of the medicinal liquid M. Alternatively, the timing of generation of the second signal may be set so that the second signal is generated when the stopper 163 reaches a position 0.5 mm to 1 mm away from the tip of the chamber 162 of the syringe 16 (the position at which the movement of the stopper 163 is completed, see FIG. 18 ) in the proximal direction (the direction of arrow A). In other words, when the second signal is generated, the administration of the medicinal liquid M may not be completed, and some medicinal liquid M may remain in the chamber 162 of the syringe 16.

[0115] After the second signal is generated in the completion signal generating unit 110B, as shown in Figure 18, the plunger 64 moves further toward the tip, causing the stopper 163 to reach the tip of the chamber 162, and the plunger 64 administers a predetermined amount of the medicinal liquid M in the cylindrical body 161 into the skin S through the puncture needle 164, thereby completing the administration of the medicinal liquid M.

[0116] After the patient K confirms the second signal and a predetermined time has passed, the patient K moves the medicinal solution administration device 10 away from the skin S to be punctured. When the patient K releases the pressing force of the medicinal solution administration device 10 against the skin S, the elastic force of the sleeve spring 40 urges the slide member 56 toward the tip. As the slide member 56 moves toward the tip, the trigger member 14 also moves toward the tip until the tip of the trigger member 14 is further distal than the puncture needle 164. As a result, the puncture needle 164 is completely covered by the trigger member 14.

[0117] This embodiment has the following advantages.

[0118] As shown in Fig. 4, medicinal solution administration device 10 includes start signal generating unit 110A that generates a first signal that notifies patient K (living body) of the start time of subcutaneous administration of medicinal solution M, and completion signal generating unit 110B that generates a second signal that notifies patient K of the completion time of subcutaneous administration of medicinal solution M, as shown in Fig. 8. As plunger 64 moves toward the tip of housing 12, start signal generating unit 110A elastically deforms elastic structure 76 by being pushed radially inward by first reduced diameter portion 112A, and after elastic structure 76 passes first reduced diameter portion 112A, elastic structure 76 elastically restores radially outward and collides with first collision target portion 114A, thereby generating the first signal. As the plunger 64 moves toward the tip of the housing 12, the elastic structure 76 is pushed radially inward by the second reduced diameter portion 112B, causing it to elastically deform, and after the elastic structure 76 passes through the second reduced diameter portion 112B, the elastic structure 76 elastically restores its shape radially outward and collides with the second impacted portion 114B, thereby generating a second signal.

[0119] According to this medicinal liquid administration device 10, the patient K can effectively recognize the start and end times of administration of the medicinal liquid M with a simple structure.

[0120] 5, the elastic structure 76 has a flexible portion 761 extending along the axial direction of the plunger 64, a flange portion 762 protruding radially outward from the flexible portion 761, and a rib 763 provided distally of the flange portion 762 and protruding from the outer surface of the flexible portion 761. A second angle θ2 formed between the axial direction of the plunger 64 and the outer surface of the rib 763 shown in FIG. 7B is smaller than a first angle θ1 formed between the axial direction of the plunger 64 and the abutment portion 84 of the flange portion 762 shown in FIG.

[0121] With this configuration, the second angle θ2 of the rib 763 is smaller than the first angle θ1 of the flange portion 762, so that the elastic structure 76 can overcome the second reduced diameter portion 112B with a smaller elastic force than when the plunger 64 starts to move toward the tip.

[0122] As shown in FIG. 5, the rib 763 extends to the abutment portion 84 of the flange portion 762, and as shown in FIG. 6, the first reduced diameter portion 112A has a notch 118 that accommodates the rib 763 of the plunger 64.

[0123] According to this configuration, by extending the rib 763 up to the abutment portion 84 of the flange 762, it is possible to prevent the flange 762 and the second reduced diameter portion 112B from coming into axial contact with each other in the completion signal generating unit 110B, which makes it easier for the flexible portion 761 of the plunger 64 to overcome the second reduced diameter portion 112B. The cutout portion 118 effectively prevents the rib 763 from coming into contact with the first reduced diameter portion 112A when the plunger 64 moves.

[0124] As shown in FIG. 12, the second reduced diameter portion 112B has two or more recessed portions 120 that are recessed radially outward and extend in the axial direction of the housing 12, into which two or more ribs 763 are inserted.

[0125] This configuration effectively prevents the plunger 64 from shifting in the circumferential direction (the direction intersecting the movement direction of the plunger 64) within the housing 12. This allows the elastic structure 76 to effectively collide with the second collision target 114B.

[0126] The second reduced diameter portion 112B includes a base end inclined surface 128 that inclines radially inward toward the tip of the housing 12 , and a curved surface portion 130 that connects the base end inclined surface 128 and the recessed portion 120 .

[0127] With this configuration, when the plunger 64 moves toward the tip, the base end inclined surface 128 can effectively elastically deform the flange portion 762 radially inward, and the curved surface portion 130 can effectively guide the rib 763 into the recess portion 120.

[0128] 8, the tip end of second reduced diameter portion 112B has tip inclined surface 124 that is inclined radially outward toward the base end. With this configuration, when flange 762 overcomes second reduced diameter portion 112B and elastically restores its original shape radially outward, tip inclined surface 124 prevents flange 762 from coming into contact with second reduced diameter portion 112B, effectively preventing the radially outward elastic restoring force of flange 762 from being reduced.

[0129] As shown in Figure 10, the elastic structure 76 has a flange portion 762 provided at the base end of the flexible portion 761 and protruding radially outward from the flexible portion 761, and the start signal generating unit 110A generates a first signal when the flange portion 762 collides with the first collision target portion 114A, and as shown in Figure 14, the completion signal generating unit 110B generates a second signal when the flange portion 762 collides with the second collision target portion 114B.

[0130] According to this configuration, the flange 762 of the plunger 64 is a part that is used in common for generating the first signal and the second signal, thereby streamlining the structure.

[0131] 5, elastic structure 76 has two or more elastic pieces 760, and each of the two or more elastic pieces 760 is provided with a rib 763. According to this configuration, as shown in FIG. 8, by bringing two or more ribs 763 into contact with second reduced diameter portion 112B, plunger 64 having elastic pieces 760 can be moved toward the tip end while aligning the axis of plunger 64 with the axis of housing 12, causing each elastic piece 760 to collide evenly and simultaneously with second impact receiving portion 114B.

[0132] The present disclosure is not limited to the above disclosure, and various configurations may be adopted without departing from the gist of the present disclosure.

Claims

1. A drug solution administration device comprising: a housing; a syringe having a cylindrical body housed within the housing and filled with a drug solution, and a puncture needle communicating with the cylindrical body for administering the drug solution into a living body; a trigger member that is pressed against a subject to be punctured and is displaced relative to the housing in a proximal direction; a plunger that is provided inside the housing and is movable relative to the syringe in a distal direction in response to the relative displacement of the trigger member, and that ejects the drug solution from the puncture needle by moving in the distal direction; a start signal generating unit that generates a first signal that indicates when administration of the drug solution into the living body has started; and a completion signal generating unit that generates a second signal that indicates when administration of the drug solution into the living body has been completed, wherein the start signal generating unit has: an elastic structure that is provided on the plunger and is elastically deformable in a radial direction; a first reduced diameter portion that is provided radially outward of the plunger and protrudes radially inward toward the plunger; and a first collision portion that is provided distally of the first reduced diameter portion, a second reduced diameter portion provided radially outward from the plunger and protruding radially inward toward the plunger so as to be disposed further distally than the first reduced diameter portion; and a second reduced diameter portion provided distally from the second reduced diameter portion; and a drug solution administration device in which, as the plunger moves toward the distal end of the housing, the elastic structure is pushed radially inward by the second reduced diameter portion and elastically deformed, and after the elastic structure passes the second reduced diameter portion, the elastic structure elastically restores radially outward to collide with the second collided portion, thereby generating the second signal.

2. A drug solution administration device according to claim 1, wherein the plunger is biased in the distal direction by the resilient force of a spring provided inside the housing, and the elastic structure has: a flexible section extending along the axial direction of the plunger; a flange provided at the base end of the flexible section and projecting radially outward from the flexible section; and a rib provided from the flange in the distal direction, extending along the outer surface of the flexible section and projecting from the outer surface; and before the plunger moves in the distal direction relative to the housing, the flange and the base end of the first reduced diameter section are held in contact with each other in the axial direction, and the flange has an abutment portion that abuts against the base end of the first reduced diameter section, and each of the abutment portion and the rib is tapered in the distal direction of the plunger, a lock pin is provided movably inside the housing and is capable of preventing the elastic structure from elastically deforming radially inward by being inserted into the elastic structure; the lock pin is movable in the proximal direction by relative displacement of the trigger member in the proximal direction; when the lock pin is inserted into the elastic structure and prevents the elastic structure from elastically deforming radially inward, the lock pin moves in the proximal direction from an elastic deformation prevented state in which the lock pin is inserted into the elastic structure and the elastic structure is prevented from elastically deforming radially inward, the lock pin moves in the proximal direction from an elastic deformation prevented state in which the lock pin is inserted into the elastic structure and the elastic structure is prevented from elastically deforming radially inward, the lock pin is released from the elastic structure and the elastic structure is elastically deformed radially inward, thereby moving the plunger in the distal direction; the start signal generating unit generates the first signal when the flange collides with the first impacted portion; The completion signal generating unit generates the second signal when the flange portion collides with the second collision target portion.

3. A medicinal liquid administration device according to claim 2, wherein the rib extends to the abutment portion of the flange portion, and the first reduced diameter portion has a notch that accommodates the rib of the plunger.

4. A drug solution administration device as described in claim 2, wherein the second reduced diameter portion is recessed radially outward and has two or more recessed portions extending in the axial direction of the housing into which two or more of the ribs are inserted.

5. A drug solution administration device according to claim 4, wherein the second reduced diameter section comprises a base end inclined surface that inclines radially inward toward the tip of the housing, and a curved surface section that connects the base end inclined surface and the recessed section.

6. A drug solution administration device according to claim 2, wherein the tip of the second reduced diameter section has a tip inclined surface that is inclined radially outward toward the base end.

7. A drug solution administration device according to claim 1, wherein the elastic structure has a flexible portion extending along the axial direction of the plunger, and a flange portion provided at the base end of the flexible portion and protruding radially outward from the flexible portion, the start signal generating portion generates the first signal when the flange portion collides with the first collision target portion, and the completion signal generating portion generates the second signal when the flange portion collides with the second collision target portion.

8. A drug solution administration device according to any one of claims 2 to 6, wherein the elastic structure has two or more elastic pieces, and each of the two or more elastic pieces is provided with the rib.

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