Positional misalignment prevention tool and needleless syringe

Abstract

This positional misalignment prevention tool for inhibiting misalignment between a target region of an eyeball into which a substance is to be injected and a syringe for injecting a substance to be injected from an injection part port into the target region comprises: a base body that is disposed around an axis following the direction of injection of the substance to be injected, such that the base body surrounds the periphery of an injection part; and an uneven part that is provided to the target-region side of the base body.

Description

Positioning prevention device and needleless syringe

[0001] The present invention relates to a displacement prevention device and a needleless syringe.

[0002] Patent document 1 discloses a device for delivering a drug into the eye, which includes a housing, at least one nozzle in a portion of the housing, a drug source within the housing, and an energy source that provides pressure to expel the drug out of the housing through the at least one nozzle.

[0003] Japanese Patent Application Laid-Open No. 2007-044529

[0004] The device in Patent Document 1 does not have a structure to prevent the injection position from shifting due to the patient's movement, etc., when injecting a drug into a patient, for example. This has led to the problem that if the injection position shifts during drug injection, lacerations may occur.

[0005] The technology disclosed herein has been made in consideration of the above-described circumstances, and aims to suppress displacement of a syringe relative to a target area of ​​the eyeball.

[0006] In order to solve the above problems, the displacement prevention device disclosed herein is a displacement prevention device for suppressing displacement between a syringe that injects an injection target substance from an injection part into a target area of ​​an eyeball to be injected and the target area, and includes a base body that is arranged around an axis that is along the injection direction of the injection target substance so as to surround the periphery of the injection part, and an uneven portion provided on the target area side of the base.

[0007] In the displacement prevention device, the syringe may be a syringe that injects the injection objective substance into the target area without using an injection needle by injecting the injection objective substance from an injection port that is the injection part.

[0008] In the displacement prevention device, the needle-free syringe may include a storage section having a storage space for storing the injection target substance and having the injection port through which the injection target substance is injected into the target area, and the base may be attached to the storage section of the needle-free syringe.

[0009] In the displacement prevention device, the needle-free syringe may include a storage section having a storage space for storing the injection target substance and having the injection outlet through which the injection target substance is injected into the target area, and a holding section for holding the storage section, and the base may be attached to the holding section of the needle-free syringe.

[0010] In the displacement prevention device, the injection part of the syringe may include an injection needle, and the base may be disposed in a position surrounding the injection needle around its axis.

[0011] In the displacement prevention device, the uneven portion may have a plurality of protrusions around the axis, and the contact surface of each protrusion that contacts the eyeball may be formed along a predetermined curved surface that corresponds to the eyeball.

[0012] In order to solve the above problems, the needle-free syringe of the present disclosure is a syringe that injects an injection target substance from an injection part into a target area of ​​an eyeball that is the injection target, and comprises: a storage part that has a storage space for storing the injection target substance and has the injection part from which the injection target substance is injected into the target area; and a positional displacement prevention device that suppresses displacement of the needle-free syringe relative to the target area, wherein the positional displacement prevention device comprises: a base that is arranged around an axis that is along the injection direction of the injection target substance so as to surround the periphery of the injection part; and an uneven part provided on the surface of the base that faces the target area.

[0013] The syringe may be a needleless syringe that injects the injection objective substance into the target area without using an injection needle by injecting the injection objective substance from an injection port that is the injection part.

[0014] The syringe may have the base attached to the housing of the needleless syringe.

[0015] The syringe may further include a holding portion that holds the container portion, and the base body may be attached to the holding portion of the needle-free syringe.

[0016] In the syringe, the injection part may include an injection needle, and the base may be disposed at a position surrounding the injection needle around the axis.

[0017] In the syringe, the uneven portion may include a plurality of protrusions around the axis, and the contact surface of each protrusion that contacts the eyeball may be formed along a predetermined curved surface that corresponds to the eyeball.

[0018] According to the present disclosure, it is possible to reduce the displacement of the syringe relative to the target area of ​​the eye.

[0019] FIG. 1 is a diagram schematically showing the appearance of a syringe. FIG. 2 is a first cross-sectional view of the syringe, which cross section is cross section AA in FIG. 4 described later. FIG. 3 is a second cross-sectional view of the syringe, which cross section is cross section BB in FIG. 4 described later, which cross section BB is perpendicular to cross section AA. FIG. 4 is a diagram showing the configuration of a housing constituting a syringe. FIG. 5 is a diagram showing the schematic configuration of a syringe assembly. FIG. 6 is a cross-sectional view showing the schematic configuration of a container. FIG. 7 is an external view showing the schematic configuration of a container. FIG. 8 is a diagram showing the schematic configuration of a displacement prevention device, and is a view (side view) of the displacement prevention device from a direction perpendicular to the injection direction of the syringe. FIG. 9 is a cross-sectional view of FIG. 8. FIG. 10 is a view of the displacement prevention device as seen from the distal end side. FIG. 11 is a view of the displacement prevention device as seen from the proximal end side. FIG. 12 is a perspective view showing the schematic configuration of the displacement prevention device. FIG. 13 is a schematic view showing the positional relationship between the abutment surface of the displacement prevention device and the injection port. Fig. 14 is a diagram showing a schematic configuration of a displacement prevention device and a container according to a second embodiment. Fig. 15 is a diagram for explaining the positional relationship between the container and the container holder according to the second embodiment. Fig. 16 is a cross-sectional view showing a schematic configuration of a displacement prevention device and a container according to a third embodiment. Fig. 17 is a view of the displacement prevention device according to the third embodiment as seen from the tip side. Fig. 18 is a schematic configuration diagram of a syringe according to a fourth embodiment. Fig. 19 is a view showing the tip side of the displacement prevention device according to the fourth embodiment. Fig. 20 is a view showing the base end side of the displacement prevention device according to the fourth embodiment. Fig. 21 is a schematic configuration diagram of a syringe according to a fifth embodiment. Fig. 22 is a view showing a cross section of the tip side of the syringe.

[0020] First Embodiment A needle-free syringe (hereinafter simply referred to as a "syringe") 1 according to an embodiment of the present disclosure will be described below with reference to the drawings. The syringe 1 is a needle-free syringe that uses the combustion energy of gunpowder to inject a projectile corresponding to the injection target substance of the present application into a target area, i.e., a device that performs an injection by injecting the projectile into a target area without using a syringe needle.

[0021] Note that the configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of configurations are possible as appropriate within the scope of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the claims. In this embodiment, the terms "distal side" and "base side" are used to describe the relative positional relationship in the longitudinal direction of the syringe 1. The "distal side" refers to a position closer to the tip of the syringe 1, i.e., closer to the ejection port 77, as described below, and the "base side" refers to the direction opposite to the "distal side" in the longitudinal direction of the syringe 1, i.e., the direction toward the igniter 22 in the syringe assembly 10 (see FIG. 5, described below).

[0022] <Configuration of syringe 1> Here, FIG. 1 is a diagram schematically illustrating the appearance of syringe 1. FIG. 2 is a first cross-sectional view of syringe 1, which cross section is cross section AA in FIG. 4 described below. FIG. 3 is a second cross-sectional view of syringe 1, which cross section is cross section BB in FIG. 4 described below, which cross section BB is perpendicular to cross section AA. FIG. 4 is a diagram showing the configuration of a housing 2 constituting syringe 1, and FIG. 5 is a diagram showing the schematic configuration of a syringe assembly 10. Syringe 1 is formed by attaching syringe assembly 10 to housing 2. Furthermore, a power cable 3 ( FIG. 1 ) for supplying a drive current to igniter 22 in syringe assembly 10 is connected to housing 2.

[0023] In the following description of the present application, the ejected liquid to be ejected into the target area by the syringe 1 is formed by containing a predetermined substance that exerts the efficacy or function expected in the target area in a liquid medium. In the ejected liquid, the predetermined substance may be dissolved in the liquid medium, or may simply be mixed without being dissolved.

[0024] Examples of the predetermined substance contained in the injection fluid include, for example, a biologically-derived substance that can be injected into a target area of ​​a living body, or a substance that exhibits a desired physiological activity. Examples of biologically-derived substances include DNA, RNA, nucleic acids, antibodies, and cells. Examples of physiologically-active substances include low-molecular-weight, protein- and peptide-based medicines, vaccines, inorganic substances such as metal particles for thermotherapy and radiotherapy, and various substances with pharmacological or therapeutic effects, including carriers. Furthermore, the liquid medium for the injection fluid may be any substance suitable for administering these predetermined substances into the target area, regardless of whether it is aqueous or oil-based. Furthermore, the viscosity of the liquid medium is not particularly limited, as long as the predetermined substance can be injected using the syringe 1.

[0025] In the syringe 1, the syringe assembly 10 is configured to be detachable from the housing 2. An accommodation space 75 (see FIG. 5 ) formed between a container (accommodating portion) 70 and a plunger 80 included in the syringe assembly 10 is filled with an injection liquid in a preparation stage before the syringe 1 is actuated, and the syringe assembly 10 is a unit that is replaced each time the injection liquid is to be injected. Details of the syringe assembly 10 will be described later.

[0026] Meanwhile, the housing 2 is formed with a grip portion 2a that the user of the syringe 1 grasps for use, and is provided with multiple switches for operating the syringe 1 to inject the injection liquid. The syringe 1 is configured so that the user can grasp and operate it with one hand. The housing 2 will now be described with reference to FIG. 4 . In FIG. 4 , (a) shows the appearance of the housing 2 as viewed from the front, (b) shows the appearance of the housing 2 as viewed from the side, (c) shows the appearance of the housing 2 as viewed from the rear, and (d) shows the appearance of the housing 2 as viewed from above. Here, the “front” refers to the portion located distal to the user when the user grasps the housing 2, which is located on the left side in FIG. 4(b), and the “rear” refers to the portion located proximal to the user, which is located on the right side in FIG. 4(b). Therefore, when a user grasps the housing 2 with one hand, the user's fingertips are placed on the front of the housing 2, which is the distal side, and the user's wrist is positioned close to the rear of the housing 2, which is the proximal side. Moreover, "upper" refers to the area on the base end side of the syringe 1.

[0027] Taking into consideration such user gripping, a grip portion 2a is provided near the front of the housing 2 to make it easier for the user's fingertips to grip. Multiple dimples are formed on the grip portion 2a to improve the grip for the user's fingertips. Furthermore, to further stabilize the user's grip of the housing, the outer periphery on the front side of the grip portion 2a is gently uneven (see FIG. 4(b)), making it easier for the user's index finger and middle finger to grip.

[0028] Furthermore, the housing 2 is provided with two operation switches, a first switch 5 and a second switch 6, for operating the syringe 1. The first switch 5 and the second switch 6 are connected to a control unit such as a microcomputer (not shown), which controls the supply of ignition current to the igniter 22 based on signals from each switch, thereby controlling the operation of the syringe 1. Here, the first switch 5 is a sliding switch provided at the rear of the housing 2, and its sliding direction is the vertical direction of the housing 2 (the direction connecting the tip and base ends). The first switch 5 is constantly biased upward, and the user can place the syringe 1 in a standby state by continuing to slide the first switch 5 downward (toward the tip) against this biasing force for a certain period of time. This standby state is a state in which the syringe 1 is ready to eject the injection liquid, and is a state in which injection is performed if the user performs additional operations.

[0029] Next, the second switch 6 is a push-down switch provided on the upper inclined surface 2b of the housing 2, and a user can push the second switch 6 inwardly of the housing 2. When the syringe 1 is placed in a standby state by operating the first switch 5, the control unit is configured to supply an ignition current to the igniter 22 by pushing the second switch 6. Furthermore, a connector 4 to which a power cable 3 is connected is provided in front of the upper inclined surface 2b of the housing 2. In this embodiment, the connector 4 is a USB connector, and the power cable 3 is detachable from the housing 2.

[0030] As described above, in this embodiment, power for operating igniter 22 is supplied from the outside via power cable 3. Alternatively, a battery for supplying power may be provided inside housing 2. In this case, as long as power remains in the battery, housing 2 can be used repeatedly by replacing syringe assembly 10. When the battery runs out of power, the battery can simply be replaced.

[0031] Here, a schematic configuration of the syringe assembly 10 is shown in Figure 5. As shown in Figures 2 and 3, the syringe assembly 10 is attached to the housing 2 to form the syringe 1, and specifically, the syringe assembly 10 is an assembly including an actuator (driving unit) 20, an attachment 30, a displacement prevention device 50, a container 70, and a plunger 80. Assembly of the syringe assembly 10 will be described later.

[0032] The actuator 20 has a cylindrical body 21. The body 21 has a central portion 21a at its center, a distal end portion 21b at its distal end, and a proximal end portion 21c at its proximal end. The distal end portion 21b, the central portion 21a, and the proximal end portion 21c of the body 21 are connected to each other through their respective internal spaces. An opening 27 is provided at the distal end of the distal end portion 21b. The proximal end portion 21c of the body 21 is fitted with an igniter 22, which is an electric igniter that burns an ignition charge to generate ejection energy. The igniter 22 has an ignition pin 22b to which an ignition current is supplied from the outside. The ignition pin 22b is coupled to the socket 7 on the housing 2 when the syringe assembly 10 is fitted to the housing 2. The igniter 22 is fitted to the body 21 in such a manner that combustion products generated by activation of the igniter 22 are released toward the central portion 21a of the body 21. That is, the igniter 22 is attached to the base end 21c of the body 21 so that the discharge surface 22c of the combustion products faces the central portion 21a.

[0033] Here, the combustion energy of the ignition charge used in the igniter 22 serves as the energy required for the syringe 1 to inject the propellant into the target area. The ignition charge may preferably be zirconium and potassium perchlorate (ZPP), titanium hydride and potassium perchlorate (THPP), titanium and potassium perchlorate (TiPP), aluminum and potassium perchlorate (APP), aluminum and bismuth oxide (ABO), aluminum and molybdenum oxide (AMO), aluminum and copper oxide (ACO), aluminum and iron oxide (AFO), or a combination of these explosives. These explosives generate high-temperature, high-pressure plasma during combustion immediately after ignition, but exhibit a characteristic whereby the generated pressure drops rapidly when the temperature returns to room temperature and the combustion products condense because they contain no gaseous components. Other explosives may also be used as long as they are capable of injecting the appropriate propellant.

[0034] The body 21 is a cylindrical member, and the internal space of the central portion 21a serves as the combustion chamber 20a. Furthermore, a male thread portion 26 is formed on a portion of the outer surface of the central portion 21a. The male thread portion 26 is configured to threadably mate with a female thread portion 32 of the attachment 30, which will be described later, and the effective lengths of the male thread portion 26 and the female thread portion 32 are determined so as to ensure the necessary connecting force between them. The internal space of the tip portion 21b adjacent to the central portion 21a is formed cylindrical, and a piston 40 is slidably disposed therein.

[0035] When the igniter 22 is activated and combustion products are released into the combustion chamber 20a, the pressure therein rises, and the piston 40 receives the pressure and slides toward the tip end. In other words, the actuator 20 has a mechanism in which the igniter 22 is the actuation source and the piston 40 is the output part.

[0036] As shown in FIG. 5 , the attachment 30 is a component for mounting the actuator 20, plunger 80, and container 70. The body 31 of the attachment 30 can be made of a known resin such as nylon 6-12, polyarylate, polybutylene terephthalate, polyphenylene sulfide, or liquid crystal polymer. These resins may also contain fillers such as glass fiber or glass filler. Polybutylene terephthalate may contain 20 to 80% by mass of glass fiber, polyphenylene sulfide may contain 20 to 80% by mass of glass fiber, and liquid crystal polymer may contain 20 to 80% by mass of mineral. The material of the attachment 30 is not limited to resin, but may also be metal or ceramic.

[0037] 5, the actuator 20 is disposed in the interior space of the body 31 from the base end to the center. In the interior space where the actuator 20 is disposed, the base end 21c of the actuator 20 is located roughly in the base end region, and the center 21a and tip end 21b of the actuator 20 are located roughly in the tip end region, which has a smaller diameter than the base end. A female thread 32 is disposed on the inner wall surface of the body 31, and the female thread 32 is formed to threadably mate with the male thread 26 provided in the center 21a of the actuator 20.

[0038] 5, a plunger 80 is disposed in the interior space of the body 31 in a region closer to the tip end than the region in which the actuator 20 is disposed. The diameter of the region in which the plunger 80 is disposed is smaller than the diameter of the region in which the tip portion 21b of the actuator 20 is disposed, allowing the plunger 80 to slide.

[0039] Furthermore, a portion of the container 70 is generally disposed in a region on the tip side of the internal space of the body 31. The region in which the container 70 is disposed communicates with a region in which the plunger 80 is disposed on its base end side, and its tip side opens to the tip surface of the attachment 30. A female thread portion 36 for attaching the container 70 is formed on the inner wall of the region in which the container 70 is disposed. The female thread portion 36 is threadedly engaged with a male thread portion 74 of the container 70 shown in Figures 6 and 7 described below, thereby realizing the connection between the attachment 30 and the container 70.

[0040] Next, the plunger 80 will be described. The plunger 80 is a member that pressurizes the injection liquid using energy received from the piston 40, and has a plunger rod 81 and a stopper portion 82. The plunger rod 81 is formed, for example, from a resin material that is suitable for pressurization, but is not limited to this and may be formed, for example, from the same type of material as the attachment 30.

[0041] A stopper portion 82 made of an elastic material such as rubber is attached to the tip side of the plunger rod 81. Specific materials that can be used for the stopper portion 82 include, for example, butyl rubber and silicone rubber. Other examples include styrene-based elastomers, hydrogenated styrene-based elastomers, and mixtures thereof with polyolefins such as polyethylene, polypropylene, polybutene, and α-olefin copolymers; oils such as liquid parabens and process oil; and powdered inorganic materials such as talc, cast, and mica. Furthermore, the stopper portion 82 can be made of various rubber materials (especially vulcanized rubbers) such as polyvinyl chloride-based elastomers, olefin-based elastomers, polyester-based elastomers, polyamide-based elastomers, polyurethane-based elastomers, natural rubber, isoprene rubber, chloroprene rubber, nitrile-butadiene rubber, and styrene-butadiene rubber, as well as mixtures thereof. Furthermore, since the stopper portion 82 pressurizes the injection liquid while sliding within the container 70 described below, the surface of the stopper portion 82 and the inner wall surface 75a of the container 70 may be coated or surface-treated with various substances in order to ensure or adjust the slidability between the stopper portion 82 and the inner wall surface 75a of the storage space 75 of the container 70. Examples of such coating agents that can be used include PTFE (polytetrafluoroethylene), silicone oil, diamond-like carbon, and nanodiamond.

[0042] FIG. 6 is a cross-sectional view showing a schematic configuration of the container 70, and FIG. 7 is an external view showing a schematic configuration of the container 70. The container 70 is a member that stores the injection liquid and defines a flow path for injecting the injection liquid pressurized by the plunger 80 into a target area. The container 70 is formed from a material that takes into consideration the pressurization by the plunger and the determination of the flow path. The container 70 of this embodiment is formed from a resin material. Note that the container 70 is not limited to a resin material and can be formed from, for example, the same type of material as the attachment 30.

[0043] The container 70 has a storage space 75 that can contain the injection liquid and is formed so that the stopper portion 82 of the plunger 80 can be advanced through it, and has a flow path 76 that connects the storage space 75 to an injection port (injection portion) 77 that faces the outside of the container 70. Specifically, the container 70 has a cylindrical body portion 70a that defines the storage space 75, and a nozzle portion 70c that is connected to the tip side of the body portion 70a and defines the flow path 76. Furthermore, the nozzle portion 70c has a tip portion 70c2 that includes a part of the flow path 76 on the injection port 77 side, and is configured to have a tapered portion 70c1 that connects the tip portion 70c2 to the body portion 70a and includes a tip-side outer surface 70c3 that is inclined with respect to the central axis of the attachment 30 in the longitudinal direction. A displacement prevention device 50, which will be described later, is fitted onto the outer periphery of the tip portion 70c2.

[0044] In the syringe assembly 10, as shown in FIG. 5 , the tip side of the plunger 80 is fitted into the accommodation space 75 of the container 70 so that the stopper portion 82 of the plunger 80 is slidable within the accommodation space 75 toward the nozzle portion 70c (toward the tip side). With the plunger 80 fitted into the container 70 in this manner, the space formed between the stopper portion 82 of the plunger 80 and the container 70 serves as a storage space for the injection liquid, i.e., a space in which the injection liquid is sealed. In other words, when the plunger 80 is fitted into the accommodation space 75 in the container 70 at its initial position, the tip surface of the stopper portion 82 and the inner wall surface of the container 70 located distal to the tip surface of the stopper portion 82 define the storage space. The flow path of the container 70 opens to the tip surface 73 of the nozzle portion 70c, and an injection port 77 is formed therein. Therefore, when the plunger 80 slides within the accommodation space 75 and the injection liquid contained in the accommodation space 75 is pressurized, the injection liquid passes through the flow path 76 and is injected from the injection port 77 .

[0045] The inner diameter of a flow path 76 provided in the container 70 is smaller than the inner diameter of the storage space 75. With this configuration, the highly pressurized injection liquid is injected to the outside from the injection port 77. A male thread portion 74 for attaching the container 70 to the attachment 30 is formed on the outer periphery of the base end side of the container 70. The male thread portion 74 is threadedly engaged with the female thread portion 36 of the attachment 30.

[0046] The tip shape of the stopper portion 82 of the plunger 80 is formed to generally match the tip shape of the storage space 75 defined by the inner wall surface 75a near the portion where the storage space 75 and the flow path 76 connect (the innermost portion of the storage space 75). In the present embodiment, the tip shapes of the stopper portion 82 and the storage space 75 are both tapered, with the diameter decreasing toward the tip. This makes it possible to minimize the gap formed between the stopper portion 82 and the inner wall surface 75a of the container 70 when the plunger 80 slides during injection of the injection liquid and reaches the innermost portion of the storage space 75, thereby preventing the injection liquid from remaining in the storage space 75 and being wasted. However, the shape of the stopper portion 82 is not limited to a specific shape as long as the desired effect is obtained in the syringe 1 of this embodiment. Furthermore, the stopper portion 82 is formed with an outer diameter slightly larger than the storage space 75 of the container 70, so that when it is fitted into the storage space 75 in a radially compressed state, it makes suitable contact with the inner wall surface 75a so as to maintain airtightness between it and the container 70. Note that the outer diameter of the stopper portion 82 does not have to be larger than the storage space 75, and may be approximately the same as the diameter of the storage space 75 as long as appropriate injection of the injection liquid is possible.

[0047] <Assembly of Syringe 1> In assembling the syringe 1, first, assembly of the syringe assembly 10 will be described. With the stopper portion 82 of the plunger 80 inserted all the way into the storage space 75 of the container 70, the plunger 80 is pulled back, connecting the injection port 77 of the container 70 to the injection liquid. Because the stopper portion 82 and the inner wall surface 75a of the storage space 75 are in close contact with each other, this pulling back operation generates negative pressure within the storage space, allowing the injection liquid to be filled into the storage space 75 through the injection port 77. The amount of pulling back of the plunger 80 at this time is set to a degree that, when the container 70 is attached to the attachment 30 in this state, the plunger 80 (plunger rod 81) protruding from the container 70 reaches the region of the internal space of the attachment 30 where the piston 40 is located.

[0048] When the container 70, with the housing space 75 filled with injection liquid, is attached to the attachment 30, the actuator 20 is inserted into the attachment 30 from the base end side. The actuator 20 is inserted until the tip surface of the piston 40, located at the tip portion 21b, reaches the base end surface of the plunger 80 within the attachment 30. At this time, the male thread portion 26 provided on the central portion 21a of the actuator 20 threads into the female thread portion 32 of the attachment 30, thereby suitably coupling the actuator 20 and the attachment 30. At this time, the piston 40 incorporated in the actuator 20 is connected to the plunger 80. Note that the connection between the piston 40 and the plunger 80 is not limited to a simple abutment, and a fitting portion may be provided at the tip of the piston 40 and the base end of the plunger 80 to fit them together.

[0049] When the actuator 20 is attached to the attachment 30 to which the container 70 and plunger 80 are attached as described above, the plunger 80 is pushed from the piston 40 toward the tip, and the plunger 80 is positioned at a predetermined position (pre-actuation position) within the container 70. At this time, as the plunger 80 is pushed, excess ejected liquid within the container 70 is discharged from the ejection port 77, leaving a predetermined amount of ejected liquid within the container 70. Note that the volume of the space for accommodating the ejected liquid formed between the plunger 80 positioned at the pre-actuation position and the container 70 is determined to be a volume that ensures an appropriate amount of ejected liquid when the syringe 1 is actuated. Therefore, when the syringe assembly 10 is assembled as described above, the amount of ejected liquid accommodated within the accommodation space 75 of the container 70, i.e., the amount of ejected ejected liquid, is set to a predetermined amount.

[0050] The syringe assembly 10 configured in this manner is loaded into the housing 2 with the ignition pin 22b of the igniter 22 fitted into the socket 7 on the housing 2. This prepares the syringe 1 for use (see FIGS. 1 to 3). The user holds the housing 2 of the syringe 1 in one hand and continues to slide the first switch 5 located at the rear of the housing 2 for a predetermined period of time to place the syringe 1 in a standby state. The user then presses the second switch 6 with the ejection port 77 in contact with the target area, activating the igniter 22. The ejection liquid is pressurized via the piston 40 and plunger 80, and is ejected, resulting in the ejection liquid being injected into the target area.

[0051] <Configuration of Misalignment Prevention Device> Next, a description will be given of the misalignment prevention device 50 provided at the tip of the syringe 1. Fig. 8 is a diagram showing a schematic configuration of the misalignment prevention device 50, and is a diagram (side view) of the misalignment prevention device 50 viewed from a direction perpendicular to the injection direction of the syringe 1. Fig. 9 is a cross-sectional view of Fig. 8, Fig. 10 is a diagram of the misalignment prevention device 50 viewed from the tip end side, Fig. 11 is a diagram of the misalignment prevention device 50 viewed from the base end side, and Fig. 12 is a perspective view showing a schematic configuration of the misalignment prevention device 50.

[0052] The misalignment prevention device 50 comprises a base 51 arranged around an axis 59 along the injection direction of the injection liquid so as to surround the injection outlet 77, and an uneven portion 52 provided on the target area side of the base 51.

[0053] The base 51 is an annular member, and the tip portion 70c2 of the nozzle portion 70c is passed through the inner space 511 and fitted onto the tip portion 70c2. That is, the displacement prevention device 50 of this embodiment is attached to the container 70 of the syringe 1. The base 51 of this embodiment is circular, but is not limited to this, and may be a C-shape or other shape with a portion of a circle missing. The displacement prevention device 50 may be attached by other connecting mechanisms such as screws or snap fit, rather than by fitting. Furthermore, the displacement prevention device 50 of this embodiment is attached detachably, but is not limited to this, and may be fixedly attached to the container 70 by adhesive bonding, welding, or the like. Furthermore, the attachment of the displacement prevention device 50 is not limited to joining the displacement prevention device 50 and the container 70, which are formed separately, but may be formed integrally with the displacement prevention device 50 and the container 70.

[0054] A base end side surface (base end surface) 513 of the base body 51 is tapered so as to fit along a tip side outer surface (tapered surface) 70c3 of the tapered portion 70c1 of the nozzle portion 70c.

[0055] The uneven portion 52 has a plurality of protruding portions 521 erected on a surface (base surface) 512 facing the target area of ​​the base 51. The plurality of protruding portions 521 are provided at intervals from one another in the circumferential direction of the base surface 512. As a result, recessed portions 522 are formed between each of the protruding portions 521. In this embodiment, the intervals between the protruding portions 521 are uniform, and the protruding portions 521 are arranged rotationally symmetrically around the axis 59.

[0056] 8 , 9 , and 12 , reference numeral 90 denotes the area where the eyeball to be injected is located when the syringe 1 is in use. When the injection port 77 of the displacement prevention device 50 is pressed against the eyeball during use of the syringe 1, the contact surface 523 at the tip of the convex portion 521 contacts the eyeball. Therefore, the contact surface 523 of each convex portion 521 is formed to conform to a predetermined curved surface corresponding to the eyeball. Here, the predetermined curved surface is, for example, a spherical surface. Forming the contact surface 523 along a spherical surface with an average diameter of an eyeball allows the displacement prevention device 50 to be used for general purposes. Alternatively, the contact surface 523 may be formed along a spherical surface slightly larger than the average diameter of an eyeball, so that when the displacement prevention device 50 is pressed against the eyeball, the inner side of the contact surface 523 primarily contacts the eyeball with a diameter smaller than the average, and the outer side of the contact surface 523 primarily contacts the eyeball with a diameter larger than the average. The predetermined curved surface along which the contact surface 523 extends is not limited to a spherical surface, and may be a curved surface that deviates from a spherical surface as long as the contact surface 523 of each convex portion 521 contacts the eyeball. For example, the contact surface 523 may be formed along an aspherical surface in the radial direction of the displacement prevention device 50, with a higher curvature on the axis 59 side (inside) and a lower curvature on the side away from the axis 59 (outside).

[0057] FIG. 13 is a schematic diagram showing the positional relationship between the contact surface 523 of the displacement prevention device 50 and the ejection port 77. As shown in FIG. 13 , the contact surface 523 and the ejection port 77 of the displacement prevention device 50 are arranged along a predetermined curved surface 91. Therefore, when the ejection port 77 of the syringe 1 is pressed against the eyeball, the contact surface 523 of each convex portion 521 comes into contact with the eyeball. Note that the configuration is not limited to the configuration in which the contact surface 523 and the ejection port 77 are arranged strictly on the predetermined curved surface 91. For example, the ejection port 77 may be arranged at a position a predetermined distance from the predetermined curved surface 91 toward the proximal end, taking into account the distance (predetermined distance) that the convex portions 521 dig into the eyeball surface. This allows the ejection port 77 to come into contact with the eyeball surface with the convex portions 521 digging into the eyeball when the ejection port 77 of the syringe 1 is pressed against the eyeball.

[0058] Thus, according to this embodiment, when the injection nozzle 77 is pressed against the eyeball during use of the syringe 1, the uneven portion 52 of the position shift prevention device 50 comes into contact with the surface of the eyeball, increasing the frictional force compared to when the injection nozzle 77 is simply pressed against the surface, thereby preventing the syringe 1 from shifting relative to the target area of ​​the eyeball.

[0059] Furthermore, since the convex portion 521 of the displacement prevention device 50 abuts against the eyeball at a position radially away from the injection port 77, contact between the surface of the eyeball and the tip of the syringe is stable, suppressing displacement.

[0060] Furthermore, since the convex portions 521 of the uneven portion 52 of the positional deviation prevention device 50 are arranged in rotational symmetry, the force exerted when the syringe 1 is pressed against the eyeball is evenly applied around the injection port 77, thereby effectively preventing the syringe 1 from shifting.

[0061] Second Embodiment This embodiment differs from the first embodiment described above in that it includes a container holder 71 that holds a container 70, and a displacement prevention device 50A is attached to the container holder (holding portion) 71. Note that the other configurations are the same as those of the first embodiment described above, and therefore the same elements are denoted by the same reference numerals, and repeated description will be omitted.

[0062] Fig. 14 is a diagram showing a schematic configuration of a displacement prevention device 50A and a container 70A according to the second embodiment. Fig. 15 is a diagram for explaining the positional relationship between the container 70A and the container holder 71 according to the second embodiment.

[0063] The container 70A of this embodiment does not have a male thread portion that threadably engages with the female thread portion 36 formed on the inner wall of the tip end of the attachment 30. Therefore, the container 70A is attached to the attachment 30 by a container holder 71. The container holder 71 has a body portion 71a that defines a space that contains the container 70A, a threaded portion 71b that is connected to the base end of the body portion 71a and has a male thread that threadably engages with the female thread portion 36, and a contact portion 71c that is connected to the tip end of the body portion 71a and has an inner surface 71c1 (see FIG. 15 ) that comes into surface contact with the tip end outer surface 70c3 of the container 70A. As shown in FIG. 15 , the contact portion 71c has an opening 71c2 that allows the tip end 70c2 of the container 70A to pass through.

[0064] A displacement prevention device 50A is provided on the distal end surface 71c3 of the container holder 71. The displacement prevention device 50A includes a base 51 arranged around an axis 59 aligned with the injection direction of the injection liquid so as to surround the periphery of the opening 71c2, and an uneven portion 52 provided on the target area side of the base 51. A proximal end surface 514 of the base 51 is attached to the distal end surface 71c3 of the container holder 71 by adhesive bonding, welding, or the like. Note that although the displacement prevention device 50 in this embodiment is fixedly attached to the container holder 71, it may also be detachably attached via screws or a joint. Furthermore, the attachment of the displacement prevention device 50 is not limited to joining the displacement prevention device 50 and the container holder 71, which are formed separately, but the displacement prevention device 50 and the container holder 71 may also be formed integrally.

[0065] The container 70A is placed in the container holder 71 having the above configuration so that the distal end 70c2 passes through the opening 71c2. At this time, the container 70A has the injection target substance filled in the placement space 75, and the plunger 80 is also loaded. In this placement state, the distal outer surface 70c3 of the container 70A and the inner surface 71c1 of the container holder 71 are in surface contact at the distal end, and the proximal end 70b of the container 70A and the threaded portion 71b of the container holder 71 are in contact at the proximal end. With the container 70A still placed in the container holder 71, the male thread formed on the threaded portion 71b of the container holder 71 is threaded into the female threaded portion 36 of the attachment 30 until the proximal end face of the proximal end 70b of the container 70A comes into contact with the end face 35a of the third region 35 of the attachment 30. As a result, the container 70A is attached to the attachment 30 in a state in which the distal end outer surface 70c3 of the container 70A is pressed by the container holder 71 from the distal end toward the proximal end, i.e., in the opposite direction to the moving direction of the plunger 80, due to the fastening force of the screw engagement. At this time, the plunger 80 is disposed across the accommodation space 75 in the container 70A and the region in the attachment 30 in which the plunger 80 is generally disposed.

[0066] The process of assembling the syringe assembly 10, such as by attaching the actuator 20 to the attachment 30 in this state, and the process of assembling the syringe 1 are the same as those in the first embodiment described above.

[0067] In this way, the syringe 1 of this embodiment is equipped with a positional deviation prevention device 50A at the tip of the container holder 71, and when the injection port 77 is pressed against the eyeball during use of the syringe 1, the uneven portion 52 of the positional deviation prevention device 50A comes into contact with the surface of the eyeball, thereby preventing the syringe 1 from shifting.

[0068] Third Embodiment This embodiment differs from the first embodiment in the configuration of the concave-convex portion 52B. Since the other configurations are the same as those of the first embodiment, the same elements are denoted by the same reference numerals, and a repeated description will be omitted.

[0069] Fig. 16 is a cross-sectional view showing the schematic configuration of a displacement prevention device 50B according to the third embodiment and a container 70, and Fig. 17 is a view of the displacement prevention device 50B as seen from the tip side. As shown in Figs. 16 and 17, the displacement prevention device 50B according to this embodiment includes a base 51 surrounding the periphery of the injection port 77 and an uneven portion 52B provided on the target area side of the base 51.

[0070] The uneven portion 52B has a plurality of convex portions 521B arranged concentrically on a surface (base surface) 512 of the base 51 facing the target area. The convex portions 521B are spaced apart from one another in the radial direction of the base surface 512. As a result, concave portions 522B are formed between the convex portions 521B. In this embodiment, the convex portions 521B are spaced apart evenly, and the convex portions 521B are arranged rotationally symmetrically around the axis 59. Although each convex portion 521B is formed in a circular shape when viewed from the tip side, it may be divided into a plurality of portions so that a portion of the circle is missing.

[0071] Thus, according to this embodiment, when the injection nozzle 77 is pressed against the eyeball during use of the syringe 1, the uneven portion 52B of the positional deviation prevention device 50B comes into contact with the surface of the eyeball, increasing the frictional force compared to when the injection nozzle 77 is simply pressed against the surface, thereby preventing the syringe 1 from shifting relative to the target area of ​​the eyeball.

[0072] Fourth Embodiment This embodiment differs from the first embodiment in that the syringe 1C is a needle-type syringe rather than a needleless syringe, and a displacement prevention device 50C is attached to the needle hub. Since the other configurations are the same as those of the first embodiment, the same elements are denoted by the same reference numerals, and a repeated description will be omitted.

[0073] Fig. 18 is a schematic diagram of a syringe 1C according to the fourth embodiment, Fig. 19 is a diagram showing the distal end side of a displacement prevention device 50C according to the fourth embodiment, and Fig. 20 is a diagram showing the proximal end side of the displacement prevention device 50C according to the fourth embodiment. As shown in Fig. 18, the syringe 1C has a syringe barrel 78, an injection rod 85, and an injection needle 60.

[0074] The syringe barrel 78 has a generally cylindrical outer barrel body 781 with a tip end 782. The tip end 782 is generally cylindrical and has a smaller diameter than the outer barrel body 781. The outer barrel body 781 and the tip end 782 are connected so that their internal spaces are in communication. That is, the tip end side of the internal space in the outer barrel body 781 is closed except for the portion that is in communication with the internal space of the tip end 782. The rear end of the outer barrel body 781 is provided with a flange (finger hook) 783 that protrudes radially from the outer circumferential surface of the cylinder.

[0075] The syringe barrel 78 is made of, for example, transparent plastic. The material of the first outer barrel 11 is not particularly limited, but may be, in addition to plastic, for example, metal, glass, or ceramic.

[0076] Syringe rod 85 has a rod-shaped rod portion 851, a gasket 852 provided at the tip of rod portion 851, and a flange 853 provided at the rear end of rod portion 851. The tip side of syringe rod 85 is inserted into the internal space of outer barrel body 781 from the rear end. Gasket 852 of syringe rod 85 inserted into the internal space of outer barrel body 781 contacts the inner circumferential surface of outer barrel body 781 and, in this state, is movable (advance / retract) toward the tip or rear end along the inner circumferential surface. In other words, syringe rod 85 is held so as to be able to advance / retract, with gasket 852 at the tip contacting the inner circumferential surface of outer barrel body 781 and maintaining an airtight internal space.

[0077] The injection needle 60 includes a needle tube (ejection portion) 61 and a needle hub 62, which are connected so that their internal spaces communicate with each other. A recess is provided on the base end side of the needle hub 62 to fit with a barrel tip 782 of a syringe barrel 78. When the barrel tip 782 of the syringe barrel 78 is fitted into the recess of the needle hub 62 and the injection needle 60 is attached to the syringe barrel 78, the internal space of the injection needle 60 communicates with the internal space of the syringe barrel 78.

[0078] In syringe 1C, which is an assembly of syringe barrel 78, syringe rod 85, and syringe needle 60, when the syringe rod 85 is moved toward the proximal end relative to syringe barrel 78 with the tip of syringe needle 60 immersed in injection liquid corresponding to the injection target substance, the injection liquid is sucked in and contained within syringe barrel 78. In addition, in syringe 1C, when the tip of syringe needle 60 is inserted into the target area with the injection liquid contained within syringe barrel 78 and syringe rod 85 is moved toward the distal end relative to syringe barrel 78, the injection liquid is pushed out and injected into the target area.

[0079] The displacement prevention device 50C of this embodiment comprises a base 51 arranged around an axis 59 along the injection direction of the injection liquid so as to surround the injection needle 60, and an uneven portion 52 provided on the target area side of the base 51.

[0080] The base 51 is an annular member, and the needle tube 61 of the injection needle 60 is passed through the inner space 511C, and is fitted onto the tip side of the needle hub 62. Note that, although the displacement prevention device 50C of this embodiment is detachably attached by fitting the base 51 and the needle hub 62 together, this is not limiting, and the displacement prevention device 50C may be fixed to the needle hub 62 by adhesive bonding, welding, or the like. Furthermore, the displacement prevention device 50C may be molded integrally with the needle hub 62.

[0081] A base end side surface (base end surface) 513 of the base body 51 is tapered so as to fit along the outer surface (tapered surface) of the tip end side of the hub 62 .

[0082] The uneven portion 52 has a plurality of protrusions 521 standing on a surface (base surface) 512 facing the target area of ​​the substrate 51. The structure and function of the uneven portion 52 are the same as those in the above-described embodiment.

[0083] When using the syringe 1C of this embodiment, the tip side of the injection needle 60 is inserted into the target area until the displacement prevention device 50C abuts against the symmetric area, and in this state the injection rod 85 is moved toward the tip side relative to the syringe barrel 78, thereby injecting the injection liquid into the target area. In this manner, in this embodiment, when the injection liquid is being injected into the target area, the uneven portion 52 of the displacement prevention device 50C comes into contact with the surface of the symmetric area (e.g., the surface of the eyeball), thereby preventing the syringe 1C from shifting relative to the target area.

[0084] Fifth Embodiment This embodiment differs from the fourth embodiment in that an injection needle 60D includes a sleeve 63 and a shield 64, and a displacement prevention device 50D is attached to the sleeve 63. Since the other configurations are the same as those of the fourth embodiment, the same elements are denoted by the same reference numerals, and a repeated description will be omitted.

[0085] Fig. 21 is a schematic diagram of a syringe 1D according to a fifth embodiment, and Fig. 22 is a diagram showing a cross section of the tip end side of the syringe 1D. In the syringe 1D of this embodiment, an injection needle 60D includes a needle tube 61, a needle hub 62, a sleeve 63, a shield 64, and a spring 65.

[0086] The sleeve 63 is a generally cylindrical member that houses the needle hub 62 and the proximal end side of the needle tube 61. The sleeve 63 houses at least the proximal end side of the shield 64 and holds the shield 64 so that it can move back and forth along the injection direction of the syringe 1D. The shield 64 is a generally cylindrical member that is arranged to radially surround the needle tube 61. A hole 641 through which the needle tube 61 passes is provided at the distal end side of the shield 64. A spring 65 is provided at the proximal end side of the shield 64, and the shield 64 is biased toward the distal end. Therefore, when the shield 64 is not subjected to an external force (when not in use), the shield 64 covers the distal end portion of the needle tube 61. When the syringe 1D is used and the shield 64 is pushed toward the proximal end, the shield 64 compresses the spring 65 and moves toward the proximal end, exposing the distal end portion of the needle tube 61.

[0087] The sleeve 63 is connected to the needle hub 62, and the needle hub 62 is fitted onto the barrel tip 782 of the syringe barrel 78, thereby attaching the injection needle 60D including the sleeve 63 to the syringe barrel 78. At this time, the injection needle 60D may be attached to the syringe barrel 78 while the syringe barrel 78 is already filled with the injection liquid, or the injection needle 60D may be attached to the syringe barrel 78 and then the injection liquid may be filled into the syringe barrel 78 via the injection needle 60D.

[0088] The displacement prevention device 50D of this embodiment comprises a base 51 arranged around an axis 59 along the injection direction of the injected liquid so as to surround the needle tube 61 and the shield 64, and an uneven portion 52 provided on the target area side of the base 51.

[0089] The base 51 is an annular member, and the needle tube 61 and shield 64 of the injection needle 60D are passed through the inner space 511D, and the base 51 is fitted to the distal end side of the sleeve 63. Note that, although the displacement prevention device 50D of this embodiment is detachably attached by fitting the base 51 and the sleeve 63 together, this is not limiting, and the displacement prevention device 50D may be fixed to the sleeve 63 by adhesion, welding, or the like. The displacement prevention device 50D may also be molded integrally with the sleeve 63.

[0090] The uneven portion 52 has a plurality of protrusions 521 standing on a surface (base surface) 512 facing the target area of ​​the substrate 51. The structure and function of the uneven portion 52 are the same as those in the above-described embodiment.

[0091] When in use, the tip of the syringe 1D is pressed against the target area. At this time, the shield 64 is located at the tip and covers the needle tube 61 until the syringe 1D touches the target area. When the shield 64 reaches the target area, it strikes the surface of the target area and stops moving forward, but the portion of the syringe 1D other than the shield 64 compresses the spring 65 and moves forward relative to the shield 64. The needle tube 61 of the syringe 1D is then inserted into the target area until the displacement prevention device 50D abuts against the target area. In this state, the injection rod 85 is moved toward the tip relative to the syringe barrel 78, thereby injecting the injected liquid into the target area. In this manner, in this embodiment, when the injected liquid is being injected into the target area, the uneven portion 52 of the displacement prevention device 50D comes into contact with the surface of the target area (e.g., the surface of the eyeball), thereby preventing the syringe 1C from shifting relative to the target area.

[0092] The above describes embodiments of the displacement prevention device 50 according to the present disclosure, but each aspect disclosed in this specification can be combined with any other feature disclosed in this specification.

[0093] DESCRIPTION OF SYMBOLS 1: Syringe 2: Housing 3: Power cable 4: Connector 7: Socket 10: Syringe assembly 20: Actuator 20a: Combustion chamber 21: Body 22: Igniter 26: Male thread portion 27: Opening 30: Attachment 31: Body 32: Female thread portion 35: Third region 36: Female thread portion 40: Piston 50: Position prevention device 50A: Position prevention device 51: Base 52: Concave and concave portion 59: Shaft 70: Container 70A: Container 70c: Nozzle portion 70c1: Tapered portion 70c2: Tip portion 70c3: Tip side outer surface 71: Container holder 73: Tip surface 74: Male thread portion 75: Storage space 75a : Inner wall surface 76 : Flow path 77 : Injection port 80 : Plunger 81 : Plunger rod 82 : Stopper portion 91 : Predetermined curved surface 511 : Inner space 512 : Base surface 521 : Convex portion 522 : Concave portion 523 : Contact surface

Claims

1. A misalignment prevention device for preventing misalignment between a syringe that injects an injection objective substance from an injection part into a target area of ​​an eyeball to be injected and the target area, comprising: a base body that is arranged around an axis that is aligned with the injection direction of the injection objective substance so as to surround the periphery of the injection part; and an uneven portion provided on the target area side of the base body.

2. A positional displacement prevention device as described in claim 1, wherein the syringe is a needleless syringe that injects the injection target substance into the target area without using an injection needle by injecting the injection target substance from an injection port which is the injection part.

3. The misalignment prevention device according to claim 2, wherein the needle-free syringe comprises a storage section having a storage space for storing the injection target substance and having the injection outlet through which the injection target substance is injected into the target area, and the base is attached to the storage section of the needle-free syringe.

4. The positional deviation prevention device according to claim 2, wherein the needle-free syringe comprises a container section having a storage space for storing the injection target substance and having an injection outlet through which the injection target substance is injected into the target area, and a holding section for holding the container section, and the base is attached to the holding section of the needle-free syringe.

5. The device for preventing displacement according to claim 1, wherein the injection part of the syringe is provided with an injection needle, and the base is disposed in a position surrounding the injection needle around the axis.

6. A position prevention device as claimed in any one of claims 2 to 5, wherein the uneven portion has a plurality of protrusions around the axis, and the contact surface of each protrusion that contacts the eyeball is formed along a specified curved surface corresponding to the eyeball.

7. A syringe for injecting an injection objective substance from an injection part into a target area of ​​an eyeball that is the subject of injection, comprising: a storage part having a storage space for storing the injection objective substance and having an injection part from which the injection objective substance is injected into the target area; and a positional deviation prevention device for suppressing deviation of the syringe relative to the target area, wherein the positional deviation prevention device comprises: a base body arranged around an axis along the injection direction of the injection objective substance so as to surround the periphery of the injection part; and an uneven part provided on the surface of the base body facing the target area.

8. The syringe according to claim 7, which is a needleless syringe that injects the injection objective substance into the target area without using an injection needle by injecting the injection objective substance from an injection port which is the injection section.

9. The syringe of claim 8, wherein said substrate is attached to said housing of said needleless syringe.

10. The syringe according to claim 8, further comprising a holder for holding the container, and the base is attached to the holder of the needleless syringe.

11. The syringe according to claim 7, wherein the ejection portion includes an injection needle, and the base is disposed in a position surrounding the injection needle around the axis.

12. The syringe according to any one of claims 7 to 11, wherein the uneven portion has a plurality of protrusions around the axis, and the contact surface of each protrusion that comes into contact with the eyeball is formed along a predetermined curved surface corresponding to the eyeball.

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