Drug solution administration device

Abstract

This drug solution administration device (10) comprises a syringe (16) including a cylindrical body (124) having therein a drug chamber (162) filled with a drug solution (M). A portion of the cylindrical body (124) in the syringe (16) is a visible part (161) that makes the drug solution (M) in the drug chamber (162) visible from the outside. The drug solution administration device (10) comprises a lens unit (19) that magnifies the visible part (161) and makes the visible part visible to a user.

Description

Drug administration device

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

[0002] The drug solution administration device of Japanese Patent No. 6154061 includes a syringe filled with a drug solution.

[0003] Before administering a drug solution using a drug solution administration device, the user checks whether the drug solution contains any impurities, whether the drug solution has changed color, etc., and also checks that the drug solution administration device is in the same condition as before use.

[0004] In the above-described drug solution administration device, it is cumbersome to check the state of the drug solution (whether or not the drug solution in the syringe contains impurities or has changed color), so there is a demand for a configuration that makes it easier to check the state of the drug solution.

[0005] (1) An aspect of the present invention is a drug solution administration device comprising: a cylindrical body having an internal chamber into which a drug solution is filled; a stopper movably disposed in the chamber and sealing the drug solution within the chamber; a syringe in which at least a portion of the cylindrical body is a visible portion having transparency that allows the drug solution within the chamber to be visible from the outside; and a lens portion that visually magnifies the visible portion to make it visible to a user.

[0006] With this drug solution administration device, before using the drug solution administration device, the user can use the lens portion to magnify and view the drug solution in the syringe, thereby effectively checking the state of use of the drug solution, the presence or absence of impurities in the drug solution, discoloration of the drug solution, etc.

[0007] (2) In the drug solution administration device described in (1) above, a housing may be provided in which the syringe is housed, and the housing may have a window portion that allows the visible portion of the syringe to be visible from outside the housing, and an attachment portion that surrounds the window portion and to which the lens portion is attached.

[0008] With this configuration, the syringe is housed in the housing, but the lens portion is provided on the mounting portion of the housing that surrounds the window portion, making it easy to check the medicinal liquid inside the syringe.

[0009] (3) In the drug solution administration device described in (2) above, the housing may have a main body surrounding the syringe, the mounting portion may have a protruding wall protruding from the outer peripheral surface of the main body, and the lens portion may be attached to the protruding wall.

[0010] With this configuration, by attaching the lens portion to the protruding wall of the attachment portion, the distance (focal length) of the lens portion from the visible portion can be effectively ensured.

[0011] (4) The drug solution administration device described in (2) or (3) above may further include a puncture needle that communicates with the cylindrical body and administers the drug solution into a living body; a hollow cylindrical needle cover that is provided inside the housing and covers the tip end of the syringe and is pressed against the living body to be punctured, thereby displacing relative to the housing in a proximal direction; a cap that is detachably provided at the tip of the needle cover and is removed when the puncture needle punctures the target; and a drive unit that is housed in the proximal side of the housing and uses a plunger to urge the stopper of the syringe toward the tip of the housing as the needle cover moves in the proximal direction.

[0012] With this configuration, the user can effectively check the state of the medicinal liquid through the lens portion before the drive unit urges the stopper of the syringe toward the tip and administers the medicinal liquid.

[0013] (5) In the drug solution administration device described in any one of (1) to (4) above, more than half of the length of the visible portion may face the lens portion in the axial direction of the syringe.

[0014] With this configuration, more than half the length of the visible portion can be seen through the lens portion, making it easier for the user to check the state of the medicinal liquid, and effectively improving the accuracy of checking the medicinal liquid.

[0015] (6) In the drug solution administration device described in any one of (2) to (4) above, the housing may have a plurality of the window portions, and each of the plurality of window portions may have the lens portion.

[0016] With this configuration, the user can check the state of the medicinal liquid in the syringe from multiple directions through the lens portions provided in the multiple windows.

[0017] (7) In the drug solution administration device described in any one of (2) to (4) above, the housing may have a plurality of the window portions, and at least one of the plurality of window portions may not have the lens portion.

[0018] With this configuration, the user can select and use the appropriate method between enlarging and checking the visible part of the syringe through a window portion equipped with a lens portion, and checking the visible part through a window portion not equipped with a lens portion without enlarging it.

[0019] (8) In the medicinal liquid administration device described in (4) above, the stopper of the syringe may be exposed through the window before the medicinal liquid is administered.

[0020] With this configuration, by checking the stopper of the syringe through the window, it is possible to easily confirm that the stopper is in a state before the drug solution is administered and before it has moved toward the tip.

[0021] (9) In the drug solution administration device according to any one of (1) to (8) above, the lens portion may be a Fresnel lens.

[0022] With this configuration, by using a Fresnel lens for the lens portion, it is possible to reduce the thickness and weight of the lens portion.

[0023] According to the present invention, before using the drug solution administration device, the user can use the lens portion to magnify and visually view the drug solution in the syringe, thereby effectively checking the state of use of the drug solution, the presence or absence of impurities in the drug solution, and discoloration of the drug solution.

[0024] FIG. 1 is an external perspective view of a drug solution administration device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the drug solution administration device shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is an enlarged plan view showing the distal end of the drug solution administration device. FIG. 5 is an enlarged side view showing the vicinity of a syringe holder in the drug solution administration device. FIG. 6 is an overall cross-sectional view showing another cross section of the drug solution administration device of FIG. 3. FIG. 7 is an enlarged cross-sectional view showing the distal end of the drug solution administration device of FIG. 6. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. FIG. 9 is an exploded perspective view of the drug solution administration device with the lens unit removed. FIG. 10 is a cross-sectional view taken along line X-X in FIG. 3. FIG. 11 is an enlarged cross-sectional view showing the vicinity of the base end of the drug solution administration device of FIG. 6. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 3. FIG. 13 is an overall cross-sectional view showing yet another cross section of the drug solution administration device of FIG. 3. FIG. 14 is an enlarged cross-sectional view showing the vicinity of the base end of the drug solution administration device of FIG. 13. FIG. 15 is a cross-sectional view taken along line XV-XV in FIG. 3. FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 6. FIG. 17 is a partially omitted perspective view of the exterior of the drug solution administration device shown in FIG. 1. FIG. 18A is an enlarged side view of the sleeve body. FIG. 18B is an enlarged perspective view showing a state in which the arm portion of the lock pin is inserted into the vertical groove. FIG. 19 is a cross-sectional view taken along line XIX-XIX in FIG. 3. FIG. 20 is a partially omitted cross-sectional view taken along line XX-XX in FIG. 3. FIG. 21 is an exploded perspective view of the drive unit shown in FIG. 17. FIG. 22 is an exploded perspective view showing a state in which the drive unit has been removed from the drug solution administration device. FIG. 23 is an enlarged perspective view showing the vicinity of the first connection portion in the drug solution administration device of FIG. 22. FIG. 24A is a first explanatory view showing a state in which the base end of the plunger is inserted into the guide groove of the end guide. FIG. 24B is an explanatory view showing the operation in the vicinity of the tip of the plunger in FIG. 24A. Fig. 25A is a second explanatory diagram showing a state in which the plunger has begun to rotate along the inclined guide portion. Fig. 25B is an explanatory diagram of the operation in the vicinity of the tip of the plunger in Fig. 25A. Fig. 26 is a partially omitted cross-sectional view taken along line XXVI-XXVI in Fig. 3. Fig. 27 is an enlarged perspective view showing the vicinity of the second connecting portion in the medicinal liquid administration device. Fig. 28 is an enlarged perspective view showing the vicinity of the coupling mechanism of the medicinal liquid administration device.29 is an enlarged front view of the vicinity of the coupling mechanism shown in FIG. 28. FIG. 30 is an external perspective view of the syringe holder. FIG. 31 is an external perspective view of the syringe holder and syringe. FIG. 32A is an enlarged perspective view showing an engagement portion between the syringe holder and the housing. FIG. 32B is an enlarged perspective view showing an engagement portion between the third protrusion of the syringe holder and the engagement recess of the housing. FIG. 33 is an explanatory diagram showing a state in which the base end of the holding arm of the cap is tilted radially outward. FIG. 34 is an explanatory diagram showing a state before assembly of the coupling mechanism. FIG. 35 is an explanatory diagram showing a state in which the coupling mechanism is being assembled. FIG. 36 is an explanatory diagram showing a state in which the cap of the chemical liquid administration device has been pulled toward the distal end. FIG. 37 is an explanatory diagram showing a state in which the cap has been removed from the chemical liquid administration device of FIG. 3. FIG. 38 is an enlarged cross-sectional view showing the vicinity of the distal end of the chemical liquid administration device of FIG. 37. FIG. 39 is an enlarged cross-sectional view showing the vicinity of the proximal end of the chemical liquid administration device of FIG. 37. FIG. 40 is an explanatory diagram showing the state in which the chemical solution administration device of FIG. 37 has begun to puncture the skin. FIG. 41 is an enlarged cross-sectional view showing the vicinity of the base end of the chemical solution administration device of FIG. 40. FIG. 42 is an explanatory diagram showing the state in which puncturing of the skin by the chemical solution administration device of FIG. 40 has been completed. FIG. 43 is an enlarged cross-sectional view showing the vicinity of the base end of the chemical solution administration device of FIG. 42. FIG. 44 is an enlarged cross-sectional view showing another cross section of the vicinity of the base end of the chemical solution administration device of FIG. 42. FIG. 45 is an explanatory diagram showing the state in which the plunger has begun to move toward the distal end in the chemical solution administration device of FIG. 44. FIG. 46 is an enlarged cross-sectional view showing the vicinity of the base end in the chemical solution administration device of FIG. 45. FIG. 47 is an explanatory diagram showing the state in which the plunger has further moved toward the distal end in the chemical solution administration device of FIG. 42 and chemical solution administration has been completed. FIG. 48 is an explanatory diagram showing the state in which the plunger has further moved toward the distal end in the chemical solution administration device of FIG. 47 after chemical solution administration has been completed. Fig. 49A is an explanatory diagram showing a state in which the plunger moves toward the distal end along the linear guide portion. Fig. 49B is an explanatory diagram of the operation in the vicinity of the distal end of the plunger in Fig. 49A. Fig. 50 is an explanatory diagram showing a state in which the puncture needle has moved toward the proximal end and is housed in the needle cover in the drug solution administration device of Fig. 48. Fig. 51 is an enlarged cross-sectional view showing the vicinity of the proximal end in the drug solution administration device of Fig. 50. Fig. 52 is a cross-sectional view showing the drug solution administration device after use.FIG. 53 is an enlarged plan view showing the tip of the drug solution administration device after use.

[0025] 1, a medicinal solution administration device 10 according to this embodiment is used, for example, to subcutaneously administer a medicinal solution M to a patient who is the user. As shown in FIGS. 1 to 3, the medicinal solution administration device 10 includes a housing 12 formed in a hollow cylindrical shape, a needle cover 14 movably housed inside the housing 12, a syringe 16 housed inside the needle cover 14, and a lens unit 19 that visually magnifies and enables viewing of the medicinal solution M (see FIG. 3) inside the syringe 16.

[0026] 1 , the housing 12 is made of a resin material. The housing 12 comprises a main body 20 that constitutes most of the overall length of the housing 12 and extends along the axial direction (indicated by arrows A and B), a sleeve body 22 that is housed on the proximal end side (indicated by arrow A) of the main body 20, and an end cap 24 that closes the proximal end of the main body 20. The syringe 16 is housed inside the housing 12.

[0027] The main body 20 has a predetermined length in the axial direction (the direction of arrows A and B). The main body 20 has an opening at its distal end and proximal end. As shown in FIG. 3 , the proximal end of the main body 20 has a pair of first engagement holes 201 that open into the peripheral wall. The pair of first engagement holes 201 penetrate the peripheral wall of the main body 20 in the radial direction. The first engagement holes 201 have a generally rectangular shape that is elongated in the circumferential direction relative to the axial direction of the main body 20 (see FIG. 1 ).

[0028] The peripheral wall of the main body 20 is provided with a plurality of windows 26. The plurality of windows 26 allow the visible portion 161 of the syringe 16 to be visible from outside the housing 12. In this embodiment, a case where a pair of windows 26 (hereinafter referred to as a first window 261 and a second window 262) is provided will be described. Note that the number of windows 26 is not limited to a pair. A single window 26 may be provided, or three or more windows 26 may be provided. The first and second windows 261, 262 are formed to penetrate the peripheral wall of the main body 20 and open at positions corresponding to the position of the cylindrical body 124 of the syringe 16 housed therein. The medicinal liquid M inside the cylindrical body 124 can be observed through the first and second windows 261, 262.

[0029] As shown in Fig. 4, the first and second window portions 261, 262 are formed elongated along the axial direction of the main body 20. The first window portion 261 and the second window portion 262 are disposed at the same position in the axial direction of the housing 12 (see Fig. 3). The first window portion 261 and the second window portion 262 are positioned on opposite sides of the main body 20 in the circumferential direction.

[0030] As shown in Fig. 3, the peripheral wall of the main body 20 has a pair of second engagement holes 202 and a pair of engagement recesses 203 (see Fig. 5). The second engagement holes 202 are provided between the first and second window portions 261, 262 and the first engagement hole 201. The second engagement holes 202 penetrate the peripheral wall of the main body 20 in the radial direction. The second engagement holes 202 have a generally rectangular shape that is elongated in the circumferential direction relative to the axial direction of the main body 20 (see Fig. 4).

[0031] 5, the engagement recess 203 is provided inside the peripheral wall and is disposed between the first and second window portions 261, 262 and the second engagement hole 202. The engagement recess 203 protrudes radially inward from the peripheral wall. The engagement recess 203 is tapered from the second engagement hole 202 toward the tip (direction of arrow B).

[0032] As shown in Fig. 6, a pair of recesses 28 are formed inside the tip of the main body 20. The recesses 28 have a rectangular cross section and are recessed radially relative to the inner circumferential surface of the main body 20. The pair of recesses 28 are arranged at positions symmetrical with respect to the axis of the main body 20 on the outer circumferential surface of the main body 20. As shown in Fig. 7, when the cap 18 is attached to the tip of the main body 20, the recesses 28 are arranged at positions facing the holding arms 148 of the cap 18.

[0033] 8 , the outer peripheral surface of the tip of the main body 20 has a plurality of support protrusions 204. Each support protrusion 204 protrudes slightly radially outward from the outer peripheral surface of the main body 20. The plurality of support protrusions 204 are spaced apart from one another along the circumferential direction of the main body 20.

[0034] As shown in FIG. 1 , the outer periphery of the main body 20 is provided with an attachment portion 121 to which the lens unit 19 is attached. As shown in FIG. 9 , the attachment portion 121 is hollow and has an internal space. The attachment portion 121 protrudes radially outward from the outer periphery of the main body 20 (see FIG. 3 ). The attachment portion 121 protrudes in a direction perpendicular to the axial direction of the housing 12. As shown in FIG. 10 , when viewed from the axial direction of the housing 12, the attachment portion 121 is substantially rectangular. As shown in FIG. 4 , in a plan view of the housing 12, the attachment portion 121 has a rectangular shape that is elongated in the axial direction of the housing 12 to correspond to the window portion 26. Note that the shape of the attachment portion 121 is not limited to a rectangular shape as long as it surrounds the window portion 26. In a plan view of the housing 12, the window portion 26 and the attachment portion 121 may have an elliptical shape.

[0035] As shown in FIG. 3 , the mounting portion 121 includes a first mounting portion 121A surrounding the first window portion 261 and a second mounting portion 121B surrounding the second window portion 262. The first mounting portion 121A and the second mounting portion 121B protrude in directions away from each other with the main body 20 of the housing 12 therebetween (see FIG. 10 ). In this embodiment, the protruding height H1 of the first mounting portion 121A and the protruding height H2 of the second mounting portion 121B relative to the outer peripheral surface of the housing 12 are the same. The protruding height H1 of the first mounting portion 121A and the protruding height H2 of the second mounting portion 121B may be different. The space in the first mounting portion 121A faces and communicates with the first window portion 261. The space in the second mounting portion 121B faces and communicates with the second window portion 262.

[0036] Each of the first and second mounting portions 121A and 121B has a cylindrical (in this embodiment, substantially rectangular cylindrical) protruding wall 125 protruding from the outer circumferential surface of the main body 20. The tip of the protruding wall 125 has a mounting surface 125A that is parallel to the axis of the housing 12.

[0037] 10 , the main body 20 is provided with a pair of support portions 205 inside. The needle cover 14 is held by the pair of support portions 205. The pair of support portions 205 protrude radially inward from the inner circumferential surface of the main body 20. The pair of support portions 205 are spaced apart in the circumferential direction of the main body 20.

[0038] As shown in Figure 11, the sleeve body 22 is hollow. The sleeve body 22 has a cylindrical main body 30, an expanded diameter portion 32 formed on the base end side (direction of arrow A) of the main body 30, and a pair of body tip portions 33 protruding from the tip of the main body 30. The main body 30 is formed with a substantially constant diameter along the axial direction (direction of arrows A and B). The inside of the main body 30 is provided with four guide ribs 34 protruding radially inward from the inner circumferential surface (see Figure 12).

[0039] 12 , the main body 30 has a plurality of radial protrusions 301. The plurality of radial protrusions 301 protrude radially outward from the outer circumferential surface of the main body 30. The plurality of radial protrusions 301 are spaced apart from one another in the circumferential direction of the main body 30.

[0040] The guide ribs 34 are spaced apart from one another at 90° intervals along the circumferential direction of the main body 30. The number of guide ribs 34 is not limited to four. At least three guide ribs 34 are provided. The guide ribs 34 protrude linearly from the inner circumferential surface radially inward with a substantially constant thickness. The radial protrusion length of each guide rib 34 is the same. A pair of guide ribs 34 are arranged facing each other across the axial center of the main body 30.

[0041] As shown in Figure 11, a lock pin 44 and a plunger 82 (described later) are housed inside the sleeve body 22 so as to be axially movable. As shown in Figures 13 and 14, the boundary between the expanded diameter portion 32 and the main body 30 is provided with a plurality of protrusions 38 that protrude radially inward. The protrusions 38 have a rectangular cross section and protrude radially outward from the inner circumferential surface of the main body 30. The base ends of the protrusions 38 form an inclined surface that gradually slopes radially inward (see Figure 14).

[0042] A flange 96 of a flexible portion 86 of a plunger 82 (described later) engages with the protrusion 38 on the proximal end side (in the direction of arrow A). The number and arrangement of the protrusions 38 correspond to the number and arrangement of the flexible portions 86.

[0043] The sleeve body 22 is housed inside the main body 20 from the base end of the main body 20, and the expanded diameter portion 32 is engaged with the inner circumferential portion of the main body 20. As a result, the base end of the expanded diameter portion 32 is housed and fixed at a position a predetermined distance from the base end of the main body 20 toward the tip end (in the direction of arrow B).

[0044] As shown in Fig. 3, the expanded diameter portion 32 has a pair of third engagement holes 321 and a pair of insertion grooves 322 (see Fig. 15). The pair of third engagement holes 321 penetrate the expanded diameter portion 32 in the radial direction. As shown in Fig. 15, the insertion grooves 322 have an arc shape that follows the outer circumferential shape of the expanded diameter portion 32. The insertion grooves 322 extend along the axial direction of the sleeve body 22.

[0045] 11, the outer peripheral surface of the main body 30 is provided with a pair of locking grooves 40 recessed radially inward. The pair of locking grooves 40 are disposed at positions symmetrical with respect to the axial center of the sleeve body 22, and a locking claw 62 of a locking pin 44, which will be described later, is engaged with the locking grooves 40.

[0046] As shown in Fig. 3, the outer peripheral surface of the main body 30 has a pair of sleeve claws 302. The sleeve claws 302 are provided at the tip of the main body 30. The pair of sleeve claws 302 protrude radially outward from the outer peripheral surface of the main body 30 (see Fig. 21). As shown in Fig. 16, when viewed in the axial direction of the sleeve body 22, the pair of sleeve claws 302 are arranged symmetrically with respect to the axial center of the main body 30.

[0047] As shown in Figure 3, a sleeve spring 42 is disposed between the outer peripheral surface of the main body 30 and the inner peripheral surface of the main body 20. The sleeve spring 42 is a resilient member formed of a coil spring. A base end 422 of the sleeve spring 42 is engaged with the tip of the expanded diameter portion 32. A tip end 423 of the sleeve spring 42 is engaged with a slide member 64, which will be described later. The resilience of the sleeve spring 42 biases the slide member 64 in a direction that moves it away from the sleeve body 22, i.e., in the tip direction (the direction of arrow B).

[0048] As shown in FIG. 17 , the sleeve spring 42 has an intermediate portion 421. The intermediate portion 421 is disposed between the base end portion 422 and the tip end portion 423. The intermediate portion 421 is provided in the center of the sleeve spring 42 in the axial direction. In the intermediate portion 421, the spirally wound coils are closely packed in the axial direction. In other words, the coil pitch in the intermediate portion 421 is smaller than the coil pitch in the base end portion 422 and the tip end portion 423. In the intermediate portion 421, adjacent coils are closely packed together to form a cylindrical outer circumferential surface. In other words, in the axial direction of the sleeve spring 42, the coils in the intermediate portion 421 are tightly wound relative to the base end portion 422 and the tip end portion 423. Because the outer periphery of the intermediate portion 421 of the sleeve spring 42 is flat, entanglement with other sleeve springs 42 is suppressed when the sleeve spring 42 is manufactured or assembled.

[0049] 18A and 18B , the main body 30 of the sleeve body 22 is provided with a vertical groove 303. The vertical groove 303 extends in the axial direction of the main body 30 and penetrates radially therethrough. The vertical groove 303 extends with a constant width.

[0050] 19 , a sleeve protrusion 331 protruding radially inward is formed on the inner surface of the body tip portion 33. When viewed in the axial direction of the sleeve body 22, the sleeve protrusion 331 is located at the center of the body tip portion 33 in the width direction.

[0051] As shown in FIG. 11 , a lock pin 44 is housed inside the sleeve body 22 so as to straddle the enlarged diameter portion 32 and the main body 30 .

[0052] The lock pin 44 is provided so as to be movable in the axial direction (direction of arrows A and B) inside the sleeve body 22. The lock pin 44 has a cylindrical pin body 46 formed in the center and a pair of arms 48 provided on the outer periphery of the pin body 46. The arms 48 are integrally connected to the base end of the pin body 46.

[0053] The pin body 46 has a flat end wall 50 formed at its base end and perpendicular to the axial direction, and extends from the center of the end wall 50 toward the tip (in the direction of arrow B). The pin body 46 has a hole 56 at its axial center, which has a constant diameter and extends axially through the end wall 50. A shaft 78 of the end cap 24 and an injection spring 58 (described later) are inserted into the hole 56.

[0054] 20 , the outer peripheral surface of the pin body 46 is provided with a plurality of grooves 52. The grooves 52 are recessed radially inward from the outer peripheral surface of the pin body 46. The grooves 52 extend along the axial direction of the pin body 46. The grooves 52 are spaced apart from one another in the circumferential direction of the pin body 46.

[0055] The base ends of the arms 48 are connected to the end wall 50 of the pin body 46 and are arranged parallel to and spaced a predetermined distance from the outer periphery of the pin body 46. Each arm 48 extends the same length toward its tip (in the direction of arrow B). As shown in Figure 18A, the tip of each arm 48 has an engagement end 60 that engages with a slide member 64, which will be described later, and a locking claw 62 formed radially inward of the engagement end 60.

[0056] 18B, the locking claw 62 is engaged with the vertical groove 303 of the sleeve body 22. By engaging the locking claw 62 with the vertical groove 303, the straightness of the locking pin 44 in the axial direction of the sleeve body 22 is ensured.

[0057] 11 , the engagement end 60 is flat and perpendicular to the extension direction of the arm portion 48. The locking claw 62 protrudes radially inward from the engagement end 60 and toward the tip (in the direction of arrow B). The cross-sectional shape of the locking claw 62 is triangular and tapers toward the tip of the arm portion 48.

[0058] A protrusion 48a protruding outward is provided at the center in the longitudinal direction of the arm portion 48. The protrusion 48a protrudes outward from the outer surface of the arm portion 48 and has a rectangular shape that is elongated in a direction perpendicular to the extension direction of the arm portion 48. The protrusion 48a is inserted into a slit hole 641 of a slide member 64, which will be described later.

[0059] Inside the main body 20, a cylindrical slide member 64 is provided on the tip side (in the direction of arrow B) of the lock pin 44.

[0060] The slide member 64 is disposed inside the main body 20 so as to be movable in the axial direction (directions of arrows A and B). The plunger 82 and the main body 30 of the sleeve body 22 are inserted into the slide member 64.

[0061] As shown in FIG. 21, the slide member 64 has a cylindrical sleeve body 64a, a tubular portion 64b disposed at the tip of the sleeve body 64a, and a pair of engagement arms 64c extending from the base end of the sleeve body 64a.

[0062] As shown in Figure 16, the inner peripheral surface of the sleeve main body 64a has a pair of sleeve guide portions 64a1. The sleeve guide portions 64a1 are recessed radially outward from the inner peripheral surface of the sleeve main body 64a and extend in the axial direction. When viewed in the axial direction of the slide member 64, the pair of sleeve guide portions 64a1 face each other. The arm portion 48 of the lock pin 44 is inserted into the sleeve guide portions 64a1. The sleeve guide portions 64a1 guide the arm portion 48 along the axial direction of the sleeve main body 64a. Relative rotation between the lock pin 44 and the slide member 64 is prevented by engaging the sleeve guide portions 64a1 and the arm portion 48.

[0063] 12, the main body 30 of the sleeve body 22 is inserted into the sleeve main body 64a. A plurality of radial protrusions 301 are disposed in the radial gap between the inner circumferential surface of the sleeve main body 64a and the main body 30 of the sleeve body 22. Radial movement of the sleeve body 22 relative to the sleeve main body 64a is restricted.

[0064] The cylindrical portion 64b has a larger diameter than the sleeve body 64a. The boundary between the sleeve body 64a and the cylindrical portion 64b has a stepped receiving portion 65. As shown in Figure 17, the receiving portion 65 holds the tip of the sleeve spring 42 that is disposed on the outer periphery of the slide member 64. The resilient force of the sleeve spring 42 urges the slide member 64 toward the tip.

[0065] The cylindrical portion 64b is formed hollow and open toward the tip (see FIG. 2). As shown in FIG. 19, the cylindrical portion 64b has a first guide portion 64g inside. When viewed in the axial direction of the slide member 64, the first guide portion 64g is a hole having a pair of first flat portions 64g1 facing each other and a pair of first curved portions 64g2 connecting the ends of the first flat portions 64g1 to each other.

[0066] As shown in FIGS. 22 and 23 , the cylindrical portion 64b has a first connecting portion 66 that is part of the coupling mechanism C. A pair of first connecting portions 66 are provided spaced apart from each other along the circumferential direction of the cylindrical portion 64b. The first connecting portions 66 are arranged symmetrically about the axis of the slide member 64. Each first connecting portion 66 has an accommodating recess 66a and first and second flexible arm portions 67a, 67b provided in the accommodating recess 66a. The accommodating recess 66a is a recess recessed radially inward from the outer peripheral surface of the cylindrical portion 64b and opens from the distal end to the proximal end of the cylindrical portion 64b. As shown in FIG. 23 , the accommodating recess 66a has a trapezoidal shape that narrows toward the proximal end of the slide member 64b. That is, side walls 661, 662 that define both sides of the accommodating recess 66a in the circumferential direction of the cylindrical portion 64b are inclined inward from the distal end to the proximal end.

[0067] The first and second flexible arms 67a, 67b are spaced apart from each other in the circumferential direction of the tubular portion 64b and are arranged along the inclined side walls 661, 662 of the accommodating recess 66a. The first and second flexible arms 67a, 67b are symmetrical with respect to the center of the accommodating recess 66a. The first and second flexible arms 67a, 67b are spaced apart from and parallel to the side walls 661, 662 of the accommodating recess 66a.

[0068] One end (end on the arrow B direction side) of the first and second flexible arms 67a and 67b is a fixed end 671, 672, which is connected to the tip of the tubular portion 64b. The first and second flexible arms 67a and 67b are inclined at an angle θ with the fixed ends 671, 672 of the first and second flexible arms 67a and 67b as base points. The angle θ is, for example, within a range of 5° to 45°. The other ends (ends on the arrow A direction side) of the first and second flexible arms 67a and 67b, which are free ends 673, 674, are not connected to the tubular portion 64b. The fixed ends 671, 672 of the first and second flexible arms 67a and 67b are positioned closer to the tip of the free ends 673, 674 of the tubular portion 64b.

[0069] The first and second flexible arms 67a, 67b have a cantilever structure that can tilt around fixed ends 671, 672. The first and second flexible arms 67a, 67b are elastically deformable. The length E from the fixed ends 671, 672 to the free ends 673, 674 of the first and second flexible arms 67a, 67b is, for example, 3 mm or more along the extension direction of the first and second flexible arms 67a, 67b. The length of the first flexible arm 67a and the length of the second flexible arm 67b are the same.

[0070] In the accommodating recess 66a, a space is provided between the first flexible arm 67a and the second flexible arm 67b, and the second connecting portion 123 of the needle cover 14, which is part of the connecting mechanism C, is accommodated in the space.

[0071] 21 , in the slide member 64, a pair of engagement arms 64c are disposed symmetrically about the axis of the slide member 64, and each engagement arm 64c protrudes toward the base end of the slide member 64. The engagement arm 64c has a slit hole 641. The slit hole 641 has a rectangular shape along the extension direction of the engagement arm 64c. The base end of the slit hole 641 has a protruding piece 642 that protrudes from the base end of the engagement arm 64c toward the tip. The protruding piece 642 is inclined inward toward the tip.

[0072] 11 , a portion of the arm portion 48 of the lock pin 44 is inserted into the slit hole 641. The engagement end 60 of the lock pin 44 can engage with the tip of the slit hole 641. The protruding portion 48a of the arm portion 48 can engage with the protruding piece 642. This engages the lock pin 44 with the slide member 64, preventing the lock pin 44 from coming off the slide member 64 in the proximal direction.

[0073] 22, the end guide 68 is disposed so as to face the tip of the slide member 64. The end guide 68 is cylindrical and has approximately the same diameter as the slide member 64. As shown in FIG. 6, a plunger 82 is inserted into the end guide 68 so as to be axially movable.

[0074] 24A , the end guide 68 has a cylindrical portion 681, and the inner circumferential surface of the cylindrical portion 681 is provided with a guide groove 70 for rotating the plunger 82. The guide groove 70 is recessed radially outward relative to the inner circumferential surface of the end guide 68. A flange portion 96 of a flexible portion 86 of the plunger 82, which will be described later, is inserted into the guide groove 70. The guide grooves 70 are arranged in four locations at equal intervals in the circumferential direction, corresponding to the number and arrangement of the flexible portions 86.

[0075] 25A , each guide groove 70 includes an inclined guide portion 72 and a linear guide portion 74. The inclined guide portion 72 is inclined toward the tip (direction of arrow B) with respect to the axial direction (direction of arrows A and B) of the end guide 68. The linear guide portion 74 extends in a straight line from the tip of the inclined guide portion 72. The width dimension along the circumferential direction of the linear guide portion 74 is approximately equal to or slightly larger than the width dimension of a flange portion 96 of the plunger 82, which will be described later.

[0076] 19, a pair of grooves 682 extending in the axial direction are formed on the outer circumferential surface of the cylindrical portion 681. The pair of grooves 682 are arranged spaced apart in the circumferential direction of the cylindrical portion 681.

[0077] As shown in FIG. 3 , the end guide 68 includes a second guide portion 68g and a stepped portion 683 provided toward the tip of the second guide portion 68g. As shown in FIG. 19 , when viewed axially of the end guide 68, the second guide portion 68g is provided radially outward of the cylindrical portion 681 and includes a pair of second flat portions 68g1 facing each other and a pair of second curved portions 68g2 connecting the ends of the second flat portions 68g1. When the cylindrical portion 64b of the slide member 64 is inserted into the outer periphery of the end guide 68, the first guide portion 64g is inserted into the outer periphery of the second guide portion 68g. The first flat portions 64g1 and the second flat portions 68g1 are disposed opposite each other. The end guide 68 and the slide member 64 are positioned circumferentially, preventing relative rotation therebetween.

[0078] 3, the stepped portion 683 protrudes radially outward beyond the second guide portion 68g and has a surface perpendicular to the axial direction of the end guide 68. When the tubular portion 64b of the slide member 64 is inserted onto the outer periphery of the end guide 68, the tip of the tubular portion 64b abuts against the stepped portion 683, preventing movement toward the tip and positioning the tubular portion 64b in the axial direction.

[0079] 19 , the body tip portion 33 of the sleeve body 22 can be inserted between the cylindrical portion 681 and the second guide portion 68g. At this time, the sleeve protrusions 331 of the sleeve body 22 are inserted into the pair of grooves 682. The sleeve body 22 and the end guide 68 are positioned relative to each other in the circumferential direction.

[0080] As shown in FIG. 3 , the inner circumferential surface of the end guide 68 has a pair of inner steps 684 located distally of the stepped portion 683. The pair of inner steps 684 are recessed radially outward relative to the inner circumferential surface of the end guide 68. When viewed in the axial direction of the end guide 68, the pair of inner steps 684 are disposed symmetrically about the axial center of the end guide 68. A pair of sleeve claws 302 of the sleeve body 22 engage with the pair of inner steps 684. When the end guide 68 is assembled to the distal end of the sleeve body 22, the inner circumferential surface of the end guide 68 moves over the sleeve claws 302, and the inner steps 684 engage with the sleeve claws 302. The sleeve body 22 and the end guide 68 are positioned in the axial direction. Relative rotation between the sleeve body 22 and the end guide 68 is prevented.

[0081] As shown in FIG. 13, the tip of the end guide 68 abuts against the flange 132 of the syringe 16, and urges the syringe 16 in the tip direction (direction of arrow B).

[0082] 11 , the end cap 24 has a lid portion 76 that closes the base end of the main body 20 and a shaft portion 78 that extends from the center of the lid portion 76 toward the tip side (in the direction of arrow B). The lid portion 76 is disk-shaped and has the same diameter as the outer diameter of the main body 20.

[0083] The cover 76 has a retaining portion 80 protruding from the end surface on the tip side and a pair of connecting pieces 81 protruding from the tip of the retaining portion 80. The retaining portion 80 is formed in an annular shape protruding from the end surface of the cover 76. The retaining portion 80 abuts against the base end of the expanded diameter portion 32 of the sleeve body 22, thereby restricting and holding the sleeve body 22 housed inside the main body 20 from moving toward the base end (direction of arrow A). As shown in FIG. 3 , the retaining portion 80 has a first claw 801. The first claw 801 protrudes radially outward from the outer peripheral surface of the retaining portion 80 (see FIG. 21 ). The first claw 801 engages with a first engagement hole 201 in the housing 12. The end cap 24 is fixed to the housing 12. The end cap 24 is positioned axially and circumferentially relative to the housing 12.

[0084] The pair of connecting pieces 81 are arranged spaced apart in the circumferential direction of the pressing portion 80. The pair of connecting pieces 81 are arranged toward the tip ends of the first claw portions 801. The pair of connecting pieces 81 include second claw portions 811. The second claw portions 811 protrude radially outward from the outer surfaces of the connecting pieces 81. The second claw portions 811 are provided at the tip ends of the connecting pieces 81. The second claw portions 811 are inclined radially outward toward the base end. The second claw portions 811 engage with the third engagement holes 321 of the sleeve body 22. This fixes the sleeve body 22 to the end cap 24. The sleeve body 22 is positioned axially and circumferentially with respect to the end cap 24.

[0085] At this time, the upper surface of the second claw portion 811 is inclined, and the inner surface of the third engagement hole 321 that abuts the upper surface is also inclined. Because the second claw portion 811 and the third engagement hole 321 are in contact with each other at inclined surfaces that are inclined with respect to the axial direction of the sleeve body 22, radially inward movement of the second claw portion 811 is suppressed, and radially inward bending of the connecting piece 81 having the second claw portion 811 is suppressed, so that the fixed state between the end cap 24 and the sleeve body 22 by the second claw portion 811 and the third engagement hole 321 is maintained.

[0086] As shown in Figure 15, the connecting piece 81 has a protruding piece 812 that protrudes radially inward. When the connecting piece 81 is inserted into the expanded diameter portion 32 of the sleeve body 22, the connecting piece 81 is inserted into the pair of insertion grooves 322. The protruding piece 812 is arranged facing radially inward of the sleeve body 22. When the connecting piece 81 having the second claw portion 811 is urged radially inward, the connecting piece 81 abuts against the insertion groove 322 of the sleeve body 22 and is thereby held in place. The second claw portion 811 is prevented from moving radially inward. The protruding piece 812 increases the rigidity of the connecting piece 81, further suppressing deflection of the connecting piece 81.

[0087] The shaft portion 78 is a shaft body extending axially toward the tip side (in the direction of arrow B). The shaft portion 78 is housed inside the main body 20 and the sleeve body 22 and extends to near the axial center of the main body 20. As shown in FIG. 26 , when viewed from the axial direction of the end cap 24, the shaft portion 78 is cross-shaped with multiple guide walls 78a. An injection spring 58 and a plunger 82 are inserted around the outer periphery of the shaft portion 78. The injection spring 58 is a coil spring and is formed long enough to correspond to the axial length of the shaft portion 78. The injection spring 58 is interposed between a plunger 82 (described later) and the end face of the cover portion 76, and the resilient force of the injection spring 58 urges the plunger 82 toward the tip side (in the direction of arrow B).

[0088] As shown in FIG. 3 , when the end cap 24 is attached to the base end of the main body 20 , the open base end is closed by the lid portion 76 , and the shaft portion 78 is positioned on the axis of the main body 20 .

[0089] 11 , the plunger 82 is cylindrical and long in the axial direction (direction of arrows A and B). The plunger 82 includes a rod main body 84 formed with a constant diameter along the axial direction, a plurality of flexible portions 86 formed on the base end side (direction of arrow A) of the rod main body 84 and divided in the circumferential direction, and an attachment portion 90 formed on the tip side (direction of arrow B) of the rod main body 84 and to which a top member 88 (described later) is attached.

[0090] As shown in Figure 2, the rod main body 84 is formed with a circular cross section. Four slide grooves 92 recessed radially inward are formed on the outer peripheral surface of the rod main body 84. The slide grooves 92 are recessed with a rectangular cross section relative to the outer peripheral surface of the rod main body 84. As shown in Figure 16, a guide rib 34 of the sleeve body 22 is inserted into each slide groove 92. The slide grooves 92 are spaced at equal intervals in the circumferential direction corresponding to the number and arrangement of the guide ribs 34. There are four slide grooves 92, corresponding to the guide ribs 34.

[0091] When the plunger 82 is housed inside the sleeve body 22 , the tip of each guide rib 34 is inserted into each slide groove 92 .

[0092] As shown in Figure 6, the rod body 84 has a first rod hole 94 (see Figure 12) extending along the axial direction (the direction of arrows A and B) inside, and the shaft portion 78 of the end cap 24, the injection spring 58, and the pin body 46 of the lock pin 44 are inserted into the first rod hole 94.

[0093] As shown in FIG. 20 , the rod main body 84 has a plurality of rod ribs 841 inside. The rod ribs 841 protrude radially inward from the inner circumferential surface of the first rod hole 94. The rod ribs 841 extend along the axial direction of the plunger 82. The rod ribs 841 are spaced apart from one another in the circumferential direction of the rod main body 84. When the pin main body 46 of the lock pin 44 is inserted into the first rod hole 94, the rod ribs 841 are engaged with the grooves 52, respectively. This improves the coaxiality of the plunger 82 with respect to the lock pin 44 when the plunger 82 moves in the axial direction. There is a clearance between the pin main body 46 and the rod main body 84.

[0094] As shown in Figure 21, the flexible portions 86 protrude in the axial direction (direction of arrow A) from the base end of the rod main body 84 and are arranged to be spaced apart from each other in the circumferential direction. The flexible portions 86 are arranged between two adjacent slide grooves 92. The base end side (direction of arrow A) of the flexible portions 86 can tilt radially, with the tip side (direction of arrow B) of the flexible portions 86 connected to the rod main body 84 as a fulcrum. As shown in Figure 14, the base end of the flexible portions 86 is provided with a flange portion 96 that protrudes radially outward. The surface of the flange portion 96 on the tip side (direction of arrow B) is an inclined surface that gradually slopes radially outward toward the base end side.

[0095] The flexible portion 86 expands radially outward relative to the rod main body 84. The small diameter portion 54 of the lock pin 44 is inserted into the flexible portion 86. The inner diameter of the flexible portion 86 is larger than the inner diameter of the first rod hole 94.

[0096] The outer diameter D1 of the flange 96 in the flexible portion 86 is slightly larger than the inner diameter D2 of the main body 30 in the sleeve body 22 (D1>D2).

[0097] In the axial direction of the plunger 82, an engagement step 821 is provided at the boundary between the flexible portion 86 and the rod main body 84. The engagement step 821 extends in a radial direction perpendicular to the axial direction of the plunger 82. When the pin main body 46 of the lock pin 44 is inserted into the first rod hole 94, the tip of the pin main body 46 engages with the engagement step 821 (see FIG. 11 ). This positions the plunger 82 relative to the lock pin 44 in the axial direction.

[0098] 21 , the mounting portion 90 has a smaller diameter than the rod main body 84. The outer peripheral surface of the mounting portion 90 is provided with a pair of engagement pieces 98 that protrude radially outward. The pair of engagement pieces 98 are engaged with the top member 88, which will be described later. The engagement pieces 98 extend in a horizontal direction perpendicular to the axial direction of the plunger 82 and are positioned symmetrically with respect to the axial center of the plunger 82.

[0099] 11 , the mounting portion 90 is provided with a second rod hole 100 extending axially (in the direction of arrows A and B). The second rod hole 100 has a smaller diameter than the first rod hole 94, and the shaft portion 78 of the end cap 24 is inserted through the second rod hole 100. The tip of the injection spring 58 engages with a step formed at the boundary between the second rod hole 100 and the first rod hole 94. As a result, the resilient force of the injection spring 58 urges the plunger 82 in a direction that moves it away from the end cap 24, i.e., toward the tip (in the direction of arrow B).

[0100] The top member 88 is cup-shaped and open on the base end side (in the direction of arrow A). The top member 88 is rotatable relative to the mounting portion 90 of the plunger 82. The top member 88 includes a cylindrical cup portion 102 disposed on the base end side, and an attachment end 104 protruding from the tip of the cup portion 102. A stopper 106 made of an elastic material is attached to the top member 88 so as to cover the outer periphery of the attachment end 104.

[0101] The mounting portion 90 of the plunger 82 is inserted from the base end side into the cup portion 102. As shown in Fig. 24B, a pair of guide grooves 108 are formed on the outer circumferential surface of the cup portion 102, penetrating radially and into which the engagement pieces 98 of the plunger 82 are inserted.

[0102] The guide grooves 108 are arranged in pairs symmetrically about the axial center of the cup portion 102. The guide grooves 108 have a horizontal portion 110 formed near the base end of the cup portion 102 and extending circumferentially, and a vertical portion 112 extending from one circumferential end to the tip end (in the direction of arrow B) perpendicular to the horizontal portion 110. The guide groove 108 is generally L-shaped and made up of the horizontal portion 110 and the vertical portion 112. The connection portion between the horizontal portion 110 and the vertical portion 112 has an inclined portion 114 inclined at a predetermined angle.

[0103] The top member 88 has the mounting portion 90 of the plunger 82 inserted into the cup portion 102, and the engagement pieces 98 inserted into the pair of guide grooves 108. This connects the top member 88 and the plunger 82 in the axial direction, allowing them to move together in the axial direction. After a stopper 106 is attached to the mounting end 104 of the top member 88, the top member 88 is inserted into the cylindrical body 124 of the syringe 16, which will be described later.

[0104] 26 , the mounting end 104 has a shaft hole 104a inside, through which the shaft portion 78 of the end cap 24 can be inserted. When viewed from the axial direction of the top member 88, the shaft hole 104a is formed in a cross shape, through which the shaft portion 78 of the end cap 24 can be inserted. By inserting the cross-shaped shaft portion 78 of the end cap 24 into the shaft hole 104a, relative rotation of the top member 88 with respect to the end cap 24 is prevented.

[0105] As shown in Fig. 6, needle cover 14 is movably disposed inside main body 20 that constitutes housing 12. As shown in Fig. 2, needle cover 14 includes a cylindrical main body 116, a pair of cover parts 118 extending from main body 116 toward the base end (in the direction of arrow A), and a pair of extension parts 119 extending from the base end of cover part 118.

[0106] The main body 116 is disposed on the tip side (in the direction of arrow B) of the needle cover 14, and an axially penetrating hole 14a opens in the center of the main body 116. The cover portions 118 are disposed symmetrically about the axis of the needle cover 14 and extend along the axial direction. As shown in FIG. 10 , when the needle cover 14 is housed inside the housing 12, the pair of cover portions 118 are held by a pair of support portions 205. A support portion 205 is disposed between each pair of cover portions 118. The cover portions 118 are held between the support portions 205 and the inner circumferential surface of the housing 12 (main body 20). The pair of support portions 205 prevent the cover portions 118 from rotating relative to the housing 12, positioning them in the rotational direction.

[0107] The main body 116 has a pair of engagement holes 120 that engage with the holding arms 148 of the cap 18. The cover 118 has a syringe guide hole 122 that is long along the axial direction. The syringe guide hole 122 and the engagement hole 120 are arranged linearly along the axial direction of the needle cover 14. The syringe guide hole 122 and the engagement hole 120 are spaced a predetermined distance apart in the axial direction of the needle cover 14.

[0108] The engagement hole 120 penetrates the main body 116 in the radial direction. The engagement hole 120 has a rectangular shape that is elongated in a direction perpendicular to the axial direction of the needle cover 14. The syringe guide hole 122 penetrates the cover 118 in the radial direction. A syringe holder 130, which will be described later, is engaged with the syringe guide hole 122 so as to be axially movable. The syringe guide hole 122 has a guide function that guides the syringe holder 130 in the axial direction.

[0109] As shown in Figure 27, the extension portion 119 extends from the center of the base end of the cover portion 118 further toward the base end. The extension portion 119 extends linearly with a substantially constant width. The base end of the extension portion 119 is provided with the second connection portion 123 of the linking mechanism C. The extension portion 119 is provided with a pair of ribs 119a. The ribs 119a are provided on both ends of the extension portion 119 in the width direction and extend along the extension portion 119. The ribs 119a protrude from the inner surface of the extension portion 119. The base ends 119b of the ribs 119a are located near the base end of the extension portion 119.

[0110] The second connecting portion 123 is part of the connecting mechanism C. As shown in Figure 28, the second connecting portion 123 can be connected to the first connecting portion 66 of the slide member 64. The connecting mechanism C has first and second connecting portions 66, 123, and can connect the tip of the slide member 64 and the base end of the needle cover 14.

[0111] The second connecting portion 123 has an extending end 123a which is gradually narrower than the extending portion 119, a convex portion 123b which is arranged at the base end of the extending end 123a, and a jaw portion 123c which is arranged at the connection site between the extending end 123a and the convex portion 123b.

[0112] The extending end 123a is inclined so as to gradually narrow in width from the base end of the extending portion 119 toward the base end (direction of arrow A). The sides of the extending end 123a in the width direction are inclined.

[0113] 29, the widthwise side portions of the extending end 123a are substantially parallel to the first and second flexible arm portions 67a, 67b. That is, the inclination angles of the widthwise side portions of the extending end 123a are substantially the same as the angle θ of the first and second flexible arm portions 67a, 67b.

[0114] The protrusions 123b protrude on both sides in the width direction perpendicular to the extension direction of the extending end 123a and the extending portion 119. The protrusions 123b are wider than the extending end 123a in the width direction, which is the circumferential direction of the tubular portion 64b. The maximum width dimension of the protrusions 123b is approximately the same as or smaller than the width dimension of the first flexible arm 67a and the second flexible arm 67b at the tip end side. The maximum width dimension of the protrusions 123b is larger than the width dimension of the first flexible arm 67a and the second flexible arm 67b at the base end side. Both ends of the protrusions 123b in the width direction have inclined surfaces 123d. Each inclined surface 123d is inclined toward the center of the protrusions 123b in the width direction in the direction away from the extending end 123a (toward the base end).

[0115] The jaw portion 123c is disposed at the connection between the tip of the protrusion 123b and the base end of the extending end 123a. The jaw portion 123c is recessed inward in the width direction from the width direction end of the protrusion 123b. The second connecting portion 123 is generally T-shaped and is composed of the extending end 123a and the protrusion 123b.

[0116] As shown in FIG. 2, the syringe 16 includes a hollow cylindrical body 124, a stopper 106 slidably inserted into the interior of the cylindrical body 124, a puncture needle 126 provided at the tip of the cylindrical body 124 and protruding toward the tip (in the direction of arrow B), and a protective cover 128 attached to the tip of the cylindrical body 124.

[0117] 3, a cylindrical syringe holder 130 is disposed on the outer periphery of the cylindrical body 124, and the cylindrical body 124 is held by the syringe holder 130. The medicinal liquid M used may be, for example, a liquid used for subcutaneous injection into the user.

[0118] The cylindrical body 124 is a hollow body formed in a substantially cylindrical shape with an opening at its base end. The interior of the cylindrical body 124 includes a drug chamber 162 filled with a drug solution M. The cylindrical body 124 includes a flange 132 that protrudes radially outward on the outer periphery of the base end. The cylindrical body 124 includes a needle holding portion 134 at its tip. The needle holding portion 134 has a reduced diameter relative to the cylindrical body 124 and protrudes toward the tip. The needle holding portion 134 holds the base end of the puncture needle 126.

[0119] The cylindrical body 124 is made of a transparent resin material. The cylindrical body 124 has a visible portion 161 that allows the remaining amount of medicinal liquid M filled in the medicine chamber 162 to be visually confirmed from the outside. The medicinal liquid M in the syringe 16 can be visually confirmed from the outside through the visible portion 161 and the window portion 26 of the housing 12. A flange 132 of the cylindrical body 124 is engaged with the base end of the syringe holder 130. This prevents the syringe 16 from moving axially relative to the syringe holder 130, and the syringe holder 130 covers the outer periphery of the syringe 16 and holds it integrally.

[0120] In the axial direction of the syringe 16 , half or more of the length of the visible portion 161 is arranged to face the first and second window portions 261 , 262 .

[0121] The stopper 106 is made of an elastic material such as rubber. The stopper 106 is attached to the mounting end 104 of the top member 88, and the stopper 106 is inserted into the chamber 162 of the cylindrical body 124 through the proximal end opening of the cylindrical body 124. The stopper 106 is housed so as to be slidable in the axial direction along the chamber 162 of the cylindrical body 124. By inserting the stopper 106 into the cylindrical body 124, the proximal end side of the cylindrical body 124 is sealed liquid-tight, and the medicinal liquid M in the chamber 162 is enclosed inside the cylindrical body 124.

[0122] Before use of the drug solution administration device 10, the stopper 106 is disposed on the base end side of the cylindrical body 124 and in a position facing the window portion 26, i.e., in the visible portion 161. The user can visually recognize the stopper 106 from the outside through the lens portion 19 and the window portion 26 (the first window portion 261 and the second window portion 262).

[0123] The puncture needle 126 is a hollow body having a flow path therein through which the medicinal liquid M flows. The puncture needle 126 protrudes from the needle holding portion 134 toward the tip. The flow path of the puncture needle 126 communicates with the interior of the cylindrical body 124 which is filled with the medicinal liquid M. The medicinal liquid M filled inside the cylindrical body 124 is discharged from the tip of the puncture needle 126 and administered to the user.

[0124] The protective cover 128 is attached to the tip of the cylindrical body 124 and covers the puncture needle 126. The protective cover 128 comprises a needle shield 136 made of an elastic material such as rubber and attached to the needle holding portion 134, and an outer cover member 138 that covers the outer periphery of the needle shield 136. The base end of the needle shield 136 is attached to the needle holding portion 134 so as to cover the puncture needle 126. The outer cover member 138 is fitted so as to make sliding contact with the outer periphery of the needle shield 136. As shown in Figure 13, an annular groove 140 recessed radially inward is formed on the outer periphery of the outer cover member 138. An inner hook 154 of the cap 18, which will be described later, engages with the annular groove 140.

[0125] As shown in FIG. 30 , syringe holder 130 includes holder body 141 and a pair of guide portions 142 that protrude radially outward from the outer circumferential surface of holder body 141. Holder body 141 is formed in a cylindrical shape. Holder body 141 includes a pair of openings 143 that penetrate radially. Openings 143 are elongated along the axial direction of holder body 141. Openings 143 allow syringe 16 housed in holder body 141 to be viewed from the outside (see FIG. 3 ). As shown in FIG. 10 , when syringe holder 130 is housed inside housing 12, the pair of openings 143 face each of first and second window portions 261, 262.

[0126] 6, the guide portions 142 are inserted into the syringe guide holes 122 of the needle cover 14. As a result, the syringe holder 130 is held inside the needle cover 14 together with the syringe 16 so as to be movable along the axial direction (direction of arrows A and B).

[0127] When the syringe 16 is held in the syringe holder 130 and housed inside the needle cover 14, the puncture needle 126 is positioned at the tip side (in the direction of arrow B), and the cylindrical body 124 is positioned so as to face the window portion 26 (see Figure 3) opened in the housing 12.

[0128] As shown in Figure 30, the syringe holder 130 further includes a holder flange 1301 and a plurality of holding pieces 1302. The holder flange 1301 is provided at the base end of the holder main body 141. The holder flange 1301 is formed to expand radially outward relative to the holder main body 141. The holder flange 1301 has a pair of wall portions 1303 provided on the outer edge of the holder flange 1301. As shown in Figure 31, the flange 132 of the syringe 16 is inserted into the holder flange 1301, and is held in place by the holder flange 1301 and the flange 132 of the syringe 16 abutting against each other in the axial direction. The outer periphery of the flange 132 is surrounded by the wall portions 1303.

[0129] Wall portion 1303 has first and second protrusions 1304a, 1304b protruding radially outward. First protrusions 1304a are provided at the ends of wall portion 1303 in the extending direction. As shown in Fig. 32A , when syringe holder 130 is inserted into housing 12, first protrusions 1304a engage with engagement grooves 127 formed in housing 12. As first protrusions 1304a engage with engagement grooves 127, syringe holder 130 is positioned and fixed in the axial direction relative to housing 12.

[0130] 30 , a pair of second protrusions 1304b are provided, protruding radially outward from the outer peripheral surface of wall portion 1303. As shown in FIG. 32B , second protrusions 1304b are engaged with second engagement holes 202 of housing 12, whereby syringe holder 130 is fixed within housing 12 in a state where it is positioned axially and circumferentially.

[0131] As shown in Figure 31, when the flange 132 of the syringe 16 is housed in the holder flange 1301, the notch 1321 of the flange 132 abuts against the first protrusion 1304a, thereby positioning the flange 132 relative to the holder flange 1301 in the circumferential direction of the syringe holder 130.

[0132] As shown in Fig. 30, the holder main body 141 has a third protrusion 1304c disposed distally from the holder flange 1301. The third protrusion 1304c is disposed distally of the second protrusion 1304b. The third protrusion 1304c protrudes radially outward from the outer peripheral surface of the holder main body 141. As shown in Fig. 5, the third protrusion 1304c is tapered from the base end to the tip.

[0133] By inserting third protrusion 1304c into engagement recess 203 of housing 12, syringe holder 130 is positioned axially and circumferentially inside housing 12 (see FIG. 32B ). Because engagement recess 203 and third protrusion 1304c are each tapered toward the distal end, inserting syringe holder 130 into housing 12 from its proximal end makes it easy to insert third protrusion 1304c into engagement recess 203.

[0134] As shown in FIG. 31 , the retaining pieces 1302 are provided at the tip of the holder body 141. The multiple retaining pieces 1302 are arranged at equal intervals in the circumferential direction of the holder body 141. The base end of each retaining piece 1302 is a fixed end fixed to the holder body 141. The tip of each retaining piece 1302 is a free end that can tilt relative to the base end. Each retaining surface inclines radially inward from the base end to the tip. When the syringe 16 is held in the syringe holder 130, the multiple retaining pieces 1302 hold the outer peripheral surface of the tip of the cylindrical body 124. The retaining pieces 1302 position the central axis of the syringe 16 coaxially with the central axis of the syringe holder 130.

[0135] 7, the cap 18 is cylindrical and has a bottom wall 144 formed at the tip and an annular peripheral wall 146 extending from the bottom wall 144 toward the base end (in the direction of arrow A). The base end of the cap 18 is open. The cap 18 has a pair of holding arms 148 that protrude axially (in the direction of arrow A) from the base end of the peripheral wall 146.

[0136] As shown in FIG. 4 , the peripheral wall 146 of the cap 18 is formed in an inverted taper shape, gradually increasing in diameter from the base end toward the bottom wall 144 at the tip. The peripheral wall 146 is gently curved from the base end toward the tip. The peripheral wall 146 has grip grooves 149. The grip grooves 149 are recessed radially inward from the outer circumferential surface of the peripheral wall 146. The grip grooves 149 extend along the circumferential direction of the cap 18. A plurality of grip grooves 149 are provided spaced apart in the axial direction of the cap 18. In other words, the peripheral wall of the cap 18 has an uneven shape with a plurality of grip grooves 149. The grip grooves 149 make it easy for a user to grip the cap 18 when holding it.

[0137] 7, the holding arms 148 are disposed radially inward relative to the peripheral wall 146 and are capable of tilting radially around the connection points with the peripheral wall 146. The base ends of the holding arms 148 are provided with outer hooks 150 that protrude radially inward. The holding arms 148 are disposed in pairs at symmetrical positions across the axial center of the cap 18.

[0138] The base end of the cap 18 has an end insertion groove 181 into which the tip of the housing 12 can be inserted. The end insertion groove 181 is provided between the peripheral wall 146 and the holding arm 148. The end insertion groove 181 is annular and recessed from the base end of the cap 18 toward the tip.

[0139] When the cap 18 is attached to the tip of the housing 12, the base end of the peripheral wall 146 abuts against the tip of the main body 20, and the pair of retaining arms 148 are inserted into the gap between the main body 20 and the needle cover 14. The pair of retaining arms 148 are positioned to face the recess 28 and the engagement hole 120, and the outer hooks 150 engage with the engagement hole 120. The tip of the housing 12 is inserted into the end insertion groove 181 of the cap 18, and the tip abuts against the end of the end insertion groove 181. The cap 18 is fixed in a state where it is positioned axially relative to the tip of the housing 12.

[0140] At this time, as shown in FIG. 8, a plurality of support protrusions 204 provided on the housing 12 come into contact with the inner peripheral surface of the cap 18, thereby supporting the cap 18 in the radial direction.

[0141] 33 , the axial length L1 of the engagement hole 120 is greater than the axial length L2 of the outer hook 150 (L1>L2). The outer hook 150 is engaged with the engagement hole 120 in a state where it can move axially (in the direction of arrows A and B).

[0142] 7, when the cap 18 is attached to the distal end of the needle cover 14, the recess 28 is positioned so as to be offset distally (in the direction of arrow B) from the engagement hole 120. The proximal end of the holding arm 148 having the outer hook 150 is positioned proximally (in the direction of arrow A) from the proximal end of the recess 28.

[0143] 13 , an inner hook 154 that protrudes radially inward is disposed inside the cap 18. The outer cover member 138 of the protective cover 128 is inserted into the inner hook 154. The inner hook 154 engages with the annular groove 140 of the outer cover member 138.

[0144] As a result, the cap 18 is engaged with the protective cover 128 via the inner hook 154, and is also engaged with the tip of the needle cover 14. With the cap 18 holding the protective cover 128, the cap 18 is attached so as to cover the needle cover 14 and the tip of the housing 12.

[0145] As shown in FIG. 1 , the lens unit 19 is provided on each of the first and second mounting portions 121A and 121B of the housing 12. As shown in FIG. 3 , the lens unit 19 (hereinafter also referred to as the "first lens unit 19A") faces the first window portion 261. The first lens unit 19A allows the visible portion 161 of the syringe 16 to be visually enlarged and visible through the first window portion 261. The lens unit 19 (hereinafter also referred to as the "second lens unit 19B") attached to the second mounting portion 121B faces the second window portion 262. The second lens unit 19B allows the visible portion 161 of the syringe 16 to be visually enlarged and visible through the second window portion 262.

[0146] In this embodiment, the first lens unit 19A and the second lens unit 19B have the same configuration, and therefore the following will describe in detail the first lens unit 19A. The second lens unit 19B is the same as the first lens unit 19A except that it is attached to the second attachment portion 121B.

[0147] The first lens unit 19A includes a lens body 191, a flange portion 192 surrounding the lens body 191, and an insertion portion 193 that is inserted into the first mounting unit 121A. The lens body 191 is formed in a flat plate shape. The lens body 191 is a Fresnel lens with a plurality of concentric grooves on its surface. The center of the Fresnel lens is located in the center of the lens body 191. The lens body 191 has a rectangular shape that corresponds to the first mounting unit 121A. The flange portion 192 protrudes outward beyond the insertion portion 193 and abuts against the mounting surface 125A of the first mounting unit 121A. The lens body 191 is arranged parallel to the axial direction of the housing 12.

[0148] The insertion portion 193 is formed in an annular shape and protrudes from the rear surface of the lens body 191 toward the syringe 16. The insertion portion 193 fits into the inner surface of the protruding wall 125, thereby holding the first lens unit 19A in the first mounting portion 121A.

[0149] In the axial direction of syringe 16, at least half the length of visible portion 161 of syringe 16 faces lens portion 19. The magnification of visible portion 161 of syringe 16 by lens portion 19 may be set to, for example, 1.1 to 2 times.

[0150] Note that the present invention is not limited to providing the lens unit 19 in each of the first and second window portions 261, 262. For example, the lens unit 19 may be attached to one of the first and second window portions 261, 262, and the other may not be provided with the lens unit 19.

[0151] As shown in Fig. 10 , each lens body 191 faces the visible portion 161 of the syringe 16 through the first and second window portions 261, 262. The visible portion 161 is visually enlarged by the lens body 191. The distance between the lens body 191 and the visible portion 161 is the focal length of the lens body 191. As shown in Fig. 3 , the distance between the lens body 191 and the visible portion 161, i.e., the focal length of the lens body 191, is set by the protruding height H1 of the first mounting portion 121A and the protruding height H2 of the second mounting portion 121B.

[0152] Next, assembly of the chemical solution administration device 10 will be described.

[0153] First, the drive unit U is constructed by assembling the end cap 24, injection spring 58, plunger 82, top member 88, end guide 68, sleeve spring 42, lock pin 44, sleeve body 22, and slide member 64 shown in Figure 21. When administering medicinal solution M using the medicinal solution administration device 10, in the initial state in which the puncture needle 126 is covered by the needle cover 14, the drive unit U has a lock mechanism R that prevents the injection spring 58 from moving the plunger 82 toward the distal end. When the needle cover 14 is pressed and moved toward the proximal end, the locked state by the lock mechanism R is released, allowing the plunger 82 to move toward the distal end.

[0154] An end cap 24 is disposed at the base end of the drive unit U, and an end guide 68 and a top member 88 are disposed at the tip end of the drive unit U (see FIG. 22). The first connection portion 66 of the slide member 64 is disposed adjacent to the end guide 68.

[0155] Next, the drive unit U shown in Fig. 22 is inserted into the housing 12 from its base end so that the first connecting portion 66 and the second connecting portion 123 of the linking mechanism C are aligned in a straight line along the axial direction (the direction of arrows A and B).

[0156] Inside the housing 12, the base end of the drive unit U moves toward the base end of the needle cover 14, and the first connecting portion 66 and the second connecting portion 123 face each other in the axial direction (the direction of arrows A and B) as shown in Fig. 34. As shown in Fig. 35, when the drive unit U is further moved toward the distal end (the direction of arrow B), the convex portion 123b of the second connecting portion 123 is inserted from the distal end of the tubular portion 64b into the accommodating recess 66a of the first connecting portion 66. In the accommodating recess 66a, the convex portion 123b is inserted between the first flexible arm portion 67a and the second flexible arm portion 67b.

[0157] When the inclined surface 123d of the protrusion 123b comes into contact with the first flexible arm 67a and the second flexible arm 67b, the first flexible arm 67a and the second flexible arm 67b are pressed in directions away from each other along the circumferential direction of the tube portion 64b, causing the first and second flexible arms 67a, 67b to tilt away from each other with the fixed ends 671, 672 as fulcrums.

[0158] The protrusions 123b and the extending ends 123a are inserted into the receiving recesses 66a while the first and second flexible arms 67a, 67b are pushed apart in the circumferential direction of the cylindrical portion 64b. As shown in Figures 28 and 29, when the protrusions 123b pass over the free ends 673, 674 of the first and second flexible arms 67a, 67b, the first and second flexible arms 67a, 67b are tilted toward each other by their respective resilient forces (shown by the two-dot chain lines in Figure 35). As a result, the protrusions 123b of the second connecting portion 123 engage with the base ends of the first and second flexible arms 67a, 67b, and the free ends 673, 674 of the first and second flexible arms 67a, 67b engage with the jaws 123c of the protrusions 123b. The first connecting portion 66 of the slide member 64 and the second connecting portion 123 of the needle cover 14 are connected in the axial direction (direction of arrows A and B) by the convex portion 123b, the first flexible arm portion 67a, and the second flexible arm portion 67b.

[0159] Next, the operation and effects of the drug solution administration device 10 will be described.

[0160] First, a case will be described in which the drug solution administration device 10 with the cap 18 attached before use is accidentally dropped onto the floor or the like with the cap 18 side (tip) first.

[0161] When the drug solution administration device 10 is dropped and the cap 18 at the tip contacts the floor or the like, an impact (load) is applied from the floor or the like to the cap 18. As a result, the impact is transmitted from the cap 18 to the needle cover 14, and the needle cover 14 may move relative to the housing 12 from a predetermined position toward the base end (direction of arrow A) (see the two-dot chain line in FIG. 7 ).

[0162] At this time, as the needle cover 14 moves, the distal end of the engagement hole 120 comes into contact with the outer hook 150 of the retaining arm 148. As the distal end of the engagement hole 120 comes into contact with the outer hook 150, the base end of the retaining arm 148, including the outer hook 150, is pressed radially outward. At this time, because the retaining arm 148 does not have a recess 28 on the radially outer side of its base end, the retaining arm 148 is restricted from tilting radially outward by the inner circumferential surface of the main body 20. The retaining arm 148 cannot tilt radially outward.

[0163] As a result, when the drug solution administration device 10 is dropped and an impact is applied to the needle cover 14, causing the needle cover 14 to move toward the proximal end, the engagement of the retaining arm 148 (outer hook 150) with the engagement hole 120 is reliably maintained, thereby restricting the movement of the needle cover 14 toward the proximal end relative to the housing 12.

[0164] That is, the holding arm 148 (outer hook 150) of the cap 18 functions as a movement restriction mechanism 156 that restricts movement of the needle cover 14 in the proximal direction relative to the housing 12 when the cap 18 is attached.

[0165] When the medicinal solution administration device 10 is accidentally dropped and the cap 18 comes into contact with the floor or the like, an inertial force acts in the proximal direction on the slide member 64 of the drive unit U. At this time, as described above, the proximal movement of the needle cover 14 relative to the housing 12 is restricted, and the first connecting portion 66 of the slide member 64 and the second connecting portion 123 of the needle cover 14 are connected to each other. Therefore, the proximal movement of the slide member 64 relative to the housing 12 is also restricted.

[0166] Therefore, even if the medicinal solution administration device 10 is accidentally dropped and an inertial force toward the proximal end acts on the needle cover 14, the movement of the slide member 64 toward the proximal end can be reliably prevented by the connecting mechanism C. As a result, it is possible to reliably prevent erroneous actuation of the drive unit U due to the inertial force.

[0167] Next, administration of the medicinal liquid M by the medicinal liquid administration device 10 will be described.

[0168] First, before using the medical solution administration device 10, the user visually checks the visible portion 161 of the syringe 16 through the lens portion 19 attached to the first attachment portion 121A and the second attachment portion 121B. The transparent visible portion 161 allows the state of the medical solution M in the medicine chamber 162 and the stopper 106 to be visually confirmed in a magnified state. The user checks, for example, the presence or absence of impurities in the medical solution M, discoloration of the medical solution M, and the pre-use position of the stopper 106 (positioned on the proximal end side of the window portion 26). After confirming that the stopper 106 is positioned in the pre-use position and that the medical solution M in the medicine chamber 162 is free of impurities and has not discolored, the user administers the medical solution using the medical solution administration device 10.

[0169] 3 and 6 , the cap 18 is removed from the housing 12 and the tip of the needle cover 14 of the drug solution administration device 10 before use. 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. As a result, as shown in FIG. 36 , the cap 18 moves away from the tip of the needle cover 14, and the outer hook 150 moves toward the tip (indicated by arrow B) within the engagement hole 120.

[0170] As the outer hook 150 moves distally, it comes into a position facing the recess 28. The cap 18 is further pulled distally (in the direction of arrow B). As a result, as shown in FIG. 33 , the outer hook 150 comes into contact with the distal end of the engagement hole 120, causing the retaining arm 148 to tilt radially outward. As the base end of the retaining arm 148, which includes the outer hook 150, moves into the recess 28, the retaining arm 148 (outer hook 150) disengages from the engagement hole 120. The retaining arm 148, including the outer hook 150, then moves distally through the recess 28 and the gap between the main body 20 and the needle cover 14.

[0171] As the cap 18 moves toward the tip, the protective cover 128 held by the inner hooks 154 moves together with the cap 18. This causes the protective cover 128 to detach from the needle holding portion 134 of the cylindrical body 124.

[0172] The engagement of the cap 18 with the needle cover 14 by the holding arm 148 is released, and the cap 18 is completely removed from the tip of the needle cover 14. As a result, as shown in Figures 37 and 38, the housing 12 and the tip of the needle cover 14 are opened, and the protective cover 128 that had been covering the puncture needle 126 is simultaneously removed.

[0173] Next, the medicinal liquid M is administered using the medicinal liquid administration device 10 with the cap 18 removed.

[0174] In the state before puncturing of the medicinal solution administration device 10, the relationship between the plunger 82 and the lock pin 44 is as shown in Figure 14. Because the lock pin 44 is inserted inside the flexible portion 86 of the plunger 82, the lock pin 44 restricts the inward tilting of the flexible portion 86. In other words, the flexible portion 86 cannot tilt inward. Because the flange 96 of the flexible portion 86 is engaged with the protrusion 38 of the sleeve body 22, the plunger 82 cannot move toward the distal end.

[0175] As shown in Figure 37, the user grasps the housing 12 and presses the tip of the needle cover 14 protruding from the tip of the housing 12 against the skin S, which will be the desired puncture site, at approximately a right angle. At this time, the tip and base ends of the medical solution administration device 10 are in the states shown in Figures 38 and 39, respectively. Next, as shown in Figures 40 and 41, the housing 12 is continuously pushed further toward the skin S (tip end, direction of arrow B). As the housing 12 is pushed toward the skin S, the needle cover 14 is pushed by the skin S and moves relative to the housing 12 in the base end direction against the elastic force of the sleeve spring 42. Figures 40 and 41 show the state in which the needle tip of the puncture needle 126 has just begun to contact the skin S.

[0176] 42 and 43 , as the housing 12 is further pressed toward the skin S, the puncture needle 126 of the syringe 16 protrudes from the hole 14a of the needle cover 14 toward the tip side (in the direction of arrow B). This causes the puncture needle 126 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 in approximately the same position as the tip of the needle cover 14.

[0177] 37 to 42, as the needle cover 14 moves in the proximal direction relative to the housing 12 as described above, the slide member 64 also moves in the proximal direction relative to the housing 12. As shown in Figures 41 and 43, as the slide member 64 moves in the proximal direction, the tip of the slit hole 641 of the slide member 64 pushes the engagement end 60 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.

[0178] 44 , as the lock pin 44 moves relative to the housing 12 toward the proximal end (direction of arrow A), the small diameter portion 54 of the lock pin 44 moves away from the inside of the flexible portion 86 of the plunger 82 toward the proximal end (direction of arrow A). This releases the locked state of the plunger 82 by the lock pin 44, and the plunger 82 starts to move toward the distal end (direction of arrow B) due to the elastic force of the injection spring 58.

[0179] When the plunger 82 starts to move distally from the state shown in Figure 44, the four flanges 96 are pushed radially inward due to contact between the tapered distal end surface and the protrusions 38. This causes each flexible portion 86 to tilt radially inward relative to the pin body 46. As shown in Figures 45 and 46, when the plunger 82 moves further distally, the flanges 96 move over the protrusions 38 and continue distally.

[0180] When the flange 96 of the plunger 82 moves over the protrusion 38, the flange 96 is displaced radially inward, and then expands radially outward again due to the elastic restoring force of the flexible portion 86, so that the outer edge contacts the inner circumferential surface of the main body 30. At this time, because the outer diameter D1 of the flange 96 is slightly larger than the inner diameter D2 of the main body 30 (see FIG. 14 ), a first recognition sound, which is a contact sound (smacking sound), is generated when the flange 96 contacts the main body 30.

[0181] After the plunger 82 starts moving toward the distal end and the collar 96 passes over the protrusion 38, the plunger 82 continues to move toward the distal end, causing the plunger 82 to start pushing the stopper 106. The medicinal solution M inside the cylindrical body 124 is pressed toward the distal end by the stopper 106. This causes the medicinal solution M to be expelled from the puncture needle 126, and administration of the medicinal solution M into the user's subcutaneous tissue begins. As described above, when the plunger 82 starts moving toward the distal end and the collar 96 passes over the protrusion 38, a first recognition sound is generated as the collar 96 collides with the main body 30. The user can confirm that administration of the medicinal solution M has begun by listening to the first recognition sound.

[0182] As the plunger 82 moves toward the distal end, it is guided by the guide ribs 34 of the sleeve body 22 inserted into the four slide grooves 92. As a result, when the plunger 82 moves toward the distal end, it moves only in the axial direction without rotating. The stopper 106 attached to the top member 88 is inserted into the cylindrical body 124 of the syringe 16.

[0183] After the administration of the medicinal liquid M has begun, the plunger 82 continues to move distally (in the direction of arrow B) at a constant speed due to the resilience of the injection spring 58. The medicinal liquid M is pushed out by the stopper 106, which moves distally within the cylindrical body 124, and the medicinal liquid M is discharged from the puncture needle 126. As the plunger 82 moves further distally, the flexible portion 86 reaches the base end of the end guide 68.

[0184] 24A , when the flange 96 comes into contact with the inclined guide portion 72, the flange 96 moves toward the tip end (in the direction of arrow B) while rotating clockwise along the inclined guide portion 72. In other words, when the plunger 82 moves along the inclined guide portion 72 of the end guide 68, a rotational force is applied to the plunger 82.

[0185] At the same time, as the plunger 82 rotates, as shown in Fig. 24B, the engagement piece 98 provided at the tip moves along the horizontal portion 110 in the guide groove 108 of the top member 88. Note that as shown in Fig. 47, the plunger 82 reaches the tip of each guide rib 34 of the sleeve body 22, and is released from the axial guide state by the slide groove 92 and the guide rib 34, allowing it to rotate.

[0186] 25A, flexible portion 86 moves toward the distal end while rotating along inclined guide portion 72 and reaches linear guide portion 74. At this point, as shown in FIG. 48, plunger 82 administers a predetermined amount of medicinal solution M from within cylindrical body 124 through puncture needle 126 into skin S, completing the administration of medicinal solution M.

[0187] 25B, before the administration of the medicinal solution M is completed, the engaging piece 98 of the rotating plunger 82 reaches the inclined portion 114 of the guide groove 108. The guide groove 70 functions as a guide means for moving the plunger 82 linearly toward the distal end (in the direction of arrow B) after rotating the plunger 82 by a predetermined amount.

[0188] After administration of the medicinal solution M is completed, the engaging piece 98 of the plunger 82 moves toward the vertical portion 112 while rotating along the inclined portion 114. Then, the engaging piece 98 of the plunger 82 moves again in the axial direction toward the distal end (the direction of arrow B) by moving along the vertical portion 112. As shown in Figures 49A and 49B, the distal end surface of the engaging piece 98 that has moved along the vertical portion 112 of the guide groove 108 comes into contact with the distal end edge of the vertical portion 112, generating a second recognition sound that is a contact sound (smacking sound).

[0189] The second recognition sound is generated a predetermined time after the completion of administration of the medicinal liquid M. The generation of the second recognition sound allows the user to confirm that administration of the medicinal liquid to the affected area (skin S) has been completed. After the user confirms the second recognition sound, the user moves the medicinal liquid administration device 10 away from the affected area.

[0190] That is, after the drug solution administration by the drug solution administration device 10 is completed, the plunger 82 is rotated by the guide groove 70 of the end guide 68, thereby slowing down the speed of movement in the axial direction. This delays the time it takes for the stopper 106 of the top member 88 connected to the plunger 82 to reach the tip of the cylindrical body 124. After a predetermined time has elapsed since the drug solution administration was completed, a second recognition sound is generated to notify the user that the drug solution administration has been completed.

[0191] When the user releases the pressing force on the skin S side of the drug solution administration device 10, the elastic force of the sleeve spring 42 urges the slide member 64 toward the tip, as shown in Figure 50. Because the tip of the slide member 64 is in contact with the rib 119a (see Figure 27) of the needle cover 14, the slide member 64 pushes the needle cover 14 toward the tip and moves toward the tip together with the needle cover 14 relative to the housing 12. The needle cover 14 moves to a position where the tip of the needle cover 14 is further distal than the puncture needle 126. As a result, the puncture needle 126 is completely covered by the needle cover 14.

[0192] 51 , because the protruding piece 642 of the slide member 64 engages with the protruding portion 48a of the lock pin 44, the lock pin 44 moves distally (in the direction of arrow B) together with the slide member 64. As the lock pin 44 moves distally, the lock claw 62 engages with the lock groove 40 of the sleeve body 22. This restricts the proximal movement of the lock pin 44 relative to the sleeve body 22. Because the slide member 64 abuts against the arm portion 48 of the lock pin 44, the proximal movement of the slide member 64 is also restricted. Because the extension portion 119 (rib 119a) of the needle cover 14 abuts against the distal end of the slide member 64, the proximal movement of the needle cover 14 is also restricted.

[0193] Since the movement of the needle cover 14 toward the base end is restricted, even if a force toward the base end acts on the needle cover 14, the puncture needle 126 is not exposed to the outside by the needle cover 14, making it safe.

[0194] 52, when the user visually checks visible portion 161 of syringe 16 through lens portion 19, first window portion 261, or second window portion 262 as shown in Fig. 53, the user can see that chamber 162 is empty of medicinal liquid M and that plunger 82 has moved toward the tip and is positioned in chamber 162. The absence of medicinal liquid M in syringe 16 and the visibility of plunger 82 enable the user to confirm that medicinal liquid administration device 10 has been used.

[0195] It should be noted that lens body 191 of lens unit 19 is not limited to being fixed to mounting portion 121. For example, a configuration may be possible in which an adjustment mechanism capable of adjusting the distance of lens body 191 from visible portion 161 is provided, and lens body 191 is movable relative to mounting portion 121 by the adjustment mechanism. By moving lens body 191 closer to or farther away from visible portion 161 by the adjustment mechanism, it is possible to adjust the focal length of lens body 191 relative to visible portion 161.

[0196] This embodiment has the following advantages.

[0197] As shown in Figure 3, the syringe 16 includes a cylindrical body 124 having a chamber 162 therein into which the medicinal liquid M is filled, and a stopper 106 that is movably disposed within the chamber 162 and seals the medicinal liquid M within the chamber 162, and at least a portion of the cylindrical body 124 is a visible portion 161 that has transparency so that the medicinal liquid M within the chamber 162 can be seen from the outside, and a lens portion 19 that visually enlarges the visible portion 161 so that it can be seen by the user.

[0198] As a result, before using the drug solution administration device 10, the user can use the lens portion 19 to magnify and view the drug solution M in the syringe 16, making it easy to check the usage status of the drug solution M, the presence or absence of impurities in the drug solution M, discoloration of the drug solution M, etc.

[0199] The syringe has a hollow cylindrical housing in which a syringe is housed, and the housing has a window portion that allows the visible portion of the syringe to be visible from outside the housing, and an attachment portion that surrounds the window portion and to which a lens portion is attached.

[0200] As a result, the syringe 16 is housed within the housing 12, but since the lens portion 19 is provided on the mounting portion 121 of the housing 12 surrounding the window portion 26, the medicinal liquid M in the syringe 16 can be easily checked.

[0201] The housing 12 has a main body 20 that surrounds the syringe 16 , the attachment portion 121 has a protruding wall 125 that protrudes from the outer peripheral surface of the main body 20 , and the lens portion 19 is attached to the protruding wall 125 .

[0202] As a result, by attaching the lens unit 19 to the attachment portion 121 having the protruding wall 125, the distance (focal length) of the lens unit 19 from the visible portion 161 can be effectively ensured.

[0203] The device comprises a puncture needle 126 that communicates with the cylindrical body 124 and administers a medicinal solution M into the living body, a hollow cylindrical needle cover 14 that is provided inside the housing 12 and covers the tip end of the syringe 16, and is displaced relative to the housing 12 in a proximal direction by being pressed against the living body to be punctured, a cap 18 that is detachably provided at the tip of the needle cover 14 and is removed when the puncture needle 126 punctures the target, and a drive unit U that is housed in the proximal side of the housing 12 and that uses a plunger 82 to urge the stopper 106 of the syringe 16 toward the tip of the housing 12 as the needle cover 14 moves in the proximal direction.

[0204] This allows the user to effectively check the state of the medicinal liquid M through the lens portion 19 before the drive unit U urges the stopper 106 of the syringe 16 toward the tip and administers the medicinal liquid M.

[0205] In the axial direction of the syringe 16 , at least half of the length of the visible portion 161 faces the lens portion 19 .

[0206] This allows more than half the length of the visible portion 161 to be visible through the lens portion 19, making it easier for the user to check the state of the medicinal liquid M and effectively improving the accuracy of checking the medicinal liquid M.

[0207] The housing 12 has a plurality of windows 26, each of which has a lens portion 19.

[0208] This allows the user to check the state of the medicinal liquid M in the syringe 16 from multiple directions through the lens portions 19 provided in the multiple window portions 26.

[0209] The housing 12 has a plurality of window portions 26, and at least one of the plurality of window portions 26 does not have a lens portion 19.

[0210] This allows the user to select between enlarging and checking the visible portion 161 of the syringe 16 through the window portion 26 equipped with the lens portion 19, and checking the visible portion 161 without enlarging it through the window portion 26 not equipped with the lens portion 19.

[0211] Before the medicinal liquid M is administered, the stopper 106 of the syringe 16 is exposed through the window portion 26 .

[0212] This allows the stopper 106 of the syringe 16 to be checked through the window 26, making it easy to confirm that the stopper 106 is in a state prior to the administration of the drug solution and before it has moved in the distal direction.

[0213] The lens portion 19 is a Fresnel lens. By using a Fresnel lens, the lens portion 19 can be made thinner and lighter.

[0214] 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.

Claims

1. A drug solution administration device comprising: a syringe having a cylindrical body having an internal chamber into which a drug solution is filled, and a stopper that is movably disposed within the chamber and seals the drug solution within the chamber, wherein at least a portion of the cylindrical body is a visible portion that has transparency that allows the drug solution within the chamber to be viewed from the outside; and a lens portion that visually magnifies the visible portion to make it visible to a user.

2. A drug solution administration device as described in claim 1, comprising a housing in which the syringe is housed, the housing having a window portion that allows the visible portion of the syringe to be viewed from outside the housing, and a mounting portion that surrounds the window portion and to which the lens portion is attached.

3. A drug solution administration device as described in claim 2, wherein the housing has a main body surrounding the syringe, the mounting portion has a protruding wall protruding from the outer peripheral surface of the main body, and the lens portion is attached to the protruding wall.

4. A drug solution administration device as described in claim 2, comprising: a puncture needle communicating with the cylindrical body for administering the drug solution into a living body; a hollow cylindrical needle cover provided inside the housing and covering the tip end of the syringe and being pressed against a target to be punctured of the living body so as to be displaced relatively in a base end direction relative to the housing; a cap removably provided at the tip of the needle cover and removed when the puncture needle punctures the target; and a drive unit housed in the base end side of the housing and using a plunger to urge the stopper of the syringe towards the tip of the housing as the needle cover moves in the base end direction.

5. A drug solution administration device according to any one of claims 1 to 4, wherein at least half of the length of the visible portion faces the lens portion in the axial direction of the syringe.

6. A drug solution administration device according to claim 2 or 3, wherein the housing has a plurality of the window portions, and each of the plurality of window portions is provided with the lens portion.

7. A drug solution administration device according to claim 2 or 3, wherein the housing has a plurality of window portions, and at least one of the plurality of window portions does not have the lens portion.

8. A drug solution administration device according to any one of claims 2 to 4, wherein the stopper of the syringe is exposed through the window before the drug solution is administered.

9. A drug solution administration device according to any one of claims 1 to 4, wherein the lens portion is a Fresnel lens.

Images