Liquid administration device

A liquid administration device includes: a structure that includes: a cylindrical body including a bottom part in a distal portion and an opening in a proximal portion, a needle tube positioned in the distal portion of the cylindrical body, the needle tube having a sharp needle tip at a distal end, wherein a proximal end of the needle tube is communicable with an inside of the cylindrical body, and a gasket installed in the cylindrical body, the gasket being slidable in an axial direction of the cylindrical body; an operation member configured to perform a pressing operation by pressing the gasket such that a liquid is discharged from the needle tube; a pressing mechanism configured to generate a pressing force for pressing the gasket; and a pressing force transmission inhibiting mechanism configured to inhibit transmission of the pressing force to the gasket during the pressing operation.

BACKGROUND

Technical Field

The present disclosure relates to a liquid administration device.

Background Art

In the related art, a prefilled syringe is known which is aseptically filled with a drug solution and can administer the drug solution.

The prefilled syringe includes a syringe outer cylinder that has an opening part through which a drug solution is discharged; a needle tube that is provided in the opening part of the syringe outer cylinder and has a sharp needle tip at a distal end of the needle tube; a gasket that is slidable in the syringe outer cylinder; a drug solution with which a space surrounded by the syringe outer cylinder and the gasket is filled; and a plunger that is interlocked with the gasket on a proximal side and discharges the drug solution through the opening part by pressing the gasket toward the distal direction. When administering a drug solution using the prefilled syringe, the living body is punctured with the needle tube and a pressing operation of the plunger is performed while maintaining the punctured state. Accordingly, the drug solution is discharged from the gasket through the opening part, and therefore, it is possible to administer the drug solution to the living body through the needle tube.

However, in the prefilled syringe in the related art, for example, there is a problem in that the pressing resistance becomes high when administering a drug solution with high viscosity, and therefore, it is difficult to perform the pressing operation of the plunger. In addition, there is a problem in that the pressing operation of the plunger is difficult when a person with a weak amount of force, rheumatism patients who have a pain or deformation in the fingers, and the like perform self administration, even with a drug solution having a low viscosity.

U.S. Patent Publication No. 2011/0092915A discloses a liquid administration device which is constituted such that a plunger is pressed in a distal direction due to biasing force of a coil spring and automatically moves in the distal direction, when administering a drug solution into a living body. According to the liquid administration device, it is possible to easily and reliably administer a drug solution even with a relatively high viscosity and to easily and reliably administer a drug solution even by a person with a weak amount of force, a patient with rheumatism who has a pain or deformation in the fingers, and the like.

However, at the time of administering a drug solution to a living body, in some cases, it is necessary to temporarily suspend the administration for reasons such as weakening of pain due to the drug solution.

However, in the liquid administration device according to U.S. Patent Publication No. 2011/0092915A, it is structurally impossible to temporarily stop the plunger, and therefore, it is impossible to temporarily suspend the administration of a drug solution.

SUMMARY

An object of certain embodiments of the present invention is to provide a liquid administration device with which it is possible to prevent a liquid from being discharged through a distal end of a needle tube when suspending administration of the liquid.

In one embodiment, a liquid administration device includes: a structure that includes: a cylindrical body including a bottom part in a distal portion and an opening in a proximal portion, the cylindrical body being fillable with a liquid, a needle tube positioned in the distal portion of the cylindrical body, the needle tube having a sharp needle tip at a distal end, wherein a proximal end of the needle tube is communicable with the inside of the cylindrical body, and a gasket installed in the cylindrical body, the gasket being slidable in an axial direction of the cylindrical body; an operation member configured to perform a pressing operation by pressing the gasket such that the liquid is discharged from the needle tube; a pressing mechanism configured to generate a pressing force for pressing the gasket; and a pressing force transmission inhibiting mechanism configured to inhibit transmission of the pressing force to the gasket during the pressing operation.

In one aspect, the pressing force transmission inhibiting mechanism is configured to inhibit the transmission of the pressing force by rotation of at least one of the operation member and the structure around a central axis.

In one aspect, the pressing force transmission inhibiting mechanism includes: a first engagement portion provided in one of the structure and the operation member, and a second engagement portion provided in the other one of the structure and the operation member. The pressing force transmission inhibiting mechanism is placeable in an engagement state in which the transmission of the pressing force to the gasket is inhibited due to the engagement between the first engagement portion and the second engagement portion, and a released state in which the pressing force is transmitted to the gasket by release of the engagement state, during the pressing operation. The liquid administration device further includes a rotary mechanism configured to allow for selection between the engagement state and the released state, by relative rotation of the first engagement portion and the second engagement portion around a central axis of the structure.

In one aspect, in the engagement state, a positional relationship between the structure and the operation member in the central axis direction of the structure is fixed, and accordingly, the transmission of the pressing force to the gasket is inhibited.

In one aspect, the second engagement portion is engageable with the first engagement portion at a plurality of locations in an axial direction of the operation member.

In one aspect, the first engagement portion has a convex portion which is provided in one of the structure and the operation member. The second engagement portion has a plurality of concave portions which are provided in parallel along an axial direction of the other one of the structure and the operation member and are engageable with the convex portion. In the engagement state, the convex portion and at least one of the concave portions are engaged with each other, a positional relationship between the structure and the operation member in a central axis direction of the structure is fixed, and accordingly, the transmission of the pressing force to the gasket is inhibited.

In one aspect, at least one of the first engagement portion and the second engagement portion is provided in the plunger of the operation member. The operation member includes an outer cylinder that is disposed outside the structure. The rotary portion includes: an inclined rail portion provided in the outer cylinder, and a slider portion provided in the plunger, the slider portion being movable along the rail. The plunger is configured so as to relatively rotate around the central axis with respect to the outer cylinder by the slider portion moving relative to the outer cylinder along the rail portion.

In one aspect, the liquid is a drug solution.

In one aspect, the pressing mechanism comprising at least one coil spring.

According to certain embodiments of the present invention, it is possible to prevent a liquid from being discharged from a distal end of a needle tube when temporarily suspending administration of the liquid, because the present invention has a pressing force transmission inhibiting portion. In addition, it is possible to restart the administration of the liquid which is once suspended. Accordingly, it is possible to prevent the liquid from being wasteful or insufficient, and to administer a sufficient amount of the liquid to a living body.

DETAILED DESCRIPTION

Hereinafter, a liquid administration device of embodiments of the present invention will be described in detail based on the preferred embodiment shown in the accompanying drawings.

First Embodiment

FIG. 1is a side view showing a first embodiment of a liquid administration device of the present invention.FIG. 2is a longitudinal sectional view of the liquid administration device shown inFIG. 1.FIG. 3is a longitudinal sectional view in which the liquid administration device shown inFIGS. 1 and 2is rotated by 90°.FIG. 4is a perspective view of an inner main body of an operation member of the liquid administration device shown inFIG. 1.FIG. 5is a perspective view of a cover member of the liquid administration device shown inFIG. 1.FIG. 6is a perspective view of an inner plunger of the operation member of the liquid administration device shown inFIG. 1.FIG. 7is a perspective view of an outer plunger of the operation member of the liquid administration device shown inFIG. 1.FIG. 8is a perspective view of an administration restricting member of the structure of the liquid administration device shown inFIG. 1.FIG. 9is a side view showing an operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 10is a longitudinal sectional view showing the operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 11is a view showing the operation state in use of the liquid administration device shown inFIG. 1in order, and is a longitudinal sectional view when the liquid administration device shown inFIGS. 9 and 10is rotated by 90°.FIG. 12is a side view showing the operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 13is a longitudinal sectional view showing the operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 14is a view showing the operation state in use of the liquid administration device shown inFIG. 1in order, and is a longitudinal sectional view when the liquid administration device shown inFIGS. 12 and 13is rotated by 90°.FIG. 15is a side view showing the operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 16is a longitudinal sectional view showing the operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 17is a view showing the operation state in use of the liquid administration device shown inFIG. 1in order, and is a longitudinal sectional view when the liquid administration device shown inFIGS. 15 and 16is rotated by 90°.FIG. 18is a side view showing the operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 19is a longitudinal sectional view showing the operation state in use of the liquid administration device shown inFIG. 1in order.FIG. 20is a view showing the operation state in use of the liquid administration device shown inFIG. 1in order, and is a longitudinal sectional view when the liquid administration device shown inFIGS. 18 and 19is rotated by 90°. Note that, hereinafter, the upper side is described as “proximal end (rear end)” or “upper (upward)”, the lower side is described as “distal end” or “lower (downward)”, and the vertical direction is described as “axial direction” or “longitudinal direction” inFIGS. 1 to 20. In addition,FIG. 1also shows a side view of a portion that is surrounded by a dotted line (circle).

A liquid administration device10shown inFIGS. 1 to 3 and 9 to 20is a medical device that is used when administering (injecting) a liquid to a living body. Note that the liquid is appropriately selected according to its purpose of use, and examples thereof include drug solutions, which are mainly injected hypodermically, such as hematopoietic agents, vaccines, hormone preparations, antirheumatic agents, anticancer agents, anesthetics, and anticoagulants.

The liquid administration device10includes a structure1; an operation member5; a cover member6that is disposed on an outer peripheral side of the structure1; a coil spring13that is a first biasing member for biasing the cover member6in the distal direction; a pressing mechanism (pressing portion)40; and a pressing force transmission inhibiting mechanism (pressing force transmission inhibiting portion)50.

As shown inFIGS. 2 and 3, the structure1includes a cylindrical body2; an administration restricting member (administration regulating portion)3; a puncture needle7that is configured to have a double ended needle (needle tube)71and a support member72; and a gasket8that is installed in the cylindrical body2and is slidable along the axial direction of the cylindrical body2.

As shown inFIGS. 2 and 3, the cylindrical body2has a cylindrical main body21. The cylindrical main body21is configured to have a member that has a bottom part22in a distal portion; a side wall23that is erected from the edge of the bottom part22; and an opening portion in a proximal portion, that is, a member forming a bottomed cylindrical shape. The inside of the cylindrical body2can be filled with a liquid.

The bottom part22of the cylindrical main body21forms a mortar shape and an opening part221, through which a liquid passes, penetrates in its central portion and opens. The diameter of the opening part221is decreased with respect to a portion of the side wall23of the cylindrical main body21. A liquid is absorbed or discharged from the opening part221.

In addition, a distal portion of the side wall23of the cylindrical main body21is positioned further on a distal side of the bottom part22, and a rib231is formed over a one turn in an outer peripheral portion of the distal portion of the side wall23.

In addition, the cylindrical body2has a sealing member (sealing portion)11that liquid-tightly seals the opening part221of the cylindrical main body21; and a fixing member12that fixes the sealing member11from its distal side. Such a cylindrical body2is disposed inside the administration restricting member3and is supported by the administration restricting member3.

The sealing member11is an elastic body, and an annular groove is formed on its proximal surface. The opening part221is liquid-tightly sealed by fitting the opening part221of the cylindrical main body21into the groove.

The fixing member12is a cylindrical member. The fixing member12is attached to the sealing member11from proximal ends and outer peripheral sides of the sealing member11and the opening part221and fixes the sealing member11to the bottom part22. Accordingly, removal of the sealing member11from the cylindrical main body21is reliably prevented. Note that the method of fixing the fixing member12is not particularly limited, and examples thereof include adhesion using adhesives, solvents, or the like; and weldings such as heat-welding, high frequency welding, and ultrasonic welding.

As shown inFIG. 8, the administration restricting member3has a main body portion31that forms a cylindrical shape. A pair of spurs (convex portions)32that are disposed so as to face each other is protrusively formed in an inner peripheral portion of the proximal portion of the main body portion31toward a central axis (inside) of the main body portion31. Note that a first engagement portion of the pressing force transmission inhibiting mechanism50is formed by the spurs32.

In addition, a pair of hooks33that are disposed so as to face each other is protrusively formed in an outer peripheral portion of the proximal portion of the main body portion31toward the central axis of the main body portion31. The shape of each hook33is not particularly limited, but in the configuration of the drawing, the shape thereof forms an L shape. Note that each hook33and each spur32are mutually disposed at substantially equiangular intervals along the circumferential direction of the main body portion31when seen from the axial direction of the main body portion31.

In addition, four elastic arm portions34are protrusively formed in the distal portion of the main body portion31in the distal direction. The arm portions34are disposed at substantially equiangular intervals along the circumferential direction of the main body portion31. Each claw35that inwardly protrudes is formed in the distal portion of each arm portion34. Each claw35is engaged with the distal side of the rib231of the cylindrical body2and each spur32is engaged with the proximal end of the cylindrical body2, and accordingly, the administration restricting member3and the cylindrical body2are interlocked with each other.

In addition, a rib36is formed over one turn in the outer peripheral portion of the distal portion of the main body portion31.

Note that the administration restricting member3is relatively movable to the operation member5in the axial direction, together with the cylindrical body2.

In addition, constituent materials for the cylindrical main body21, the administration restricting member3, the fixing member12, the cover member6, the support member72, and the operation member5are not particularly limited, and examples thereof include various types of resins such as polyvinyl chloride, polyethylene, polypropylene, cyclic polyolefin, polystyrene, poly-(4-methylpentene-1), polycarbonate, acrylic resins, acrylonitrile-butadiene-styrene copolymers, polyesters such as polyethylene terephthalate and polyethylene naphthalate, butadiene-styrene copolymers, and polyamides (for example, nylon 6, nylon 6-6, nylon 6-10 and nylon 12). Among these, resins such as polypropylene, cyclic polyolefin, polyesters and poly-(4-methylpentene-1) are preferable in view of the ease in molding.

In addition, elastic materials constituting the sealing member11and the gasket8are not particularly limited, and examples thereof include elastic materials such as various rubber materials such as natural rubber, butyl rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, and silicone rubber; various types of thermoplastic elastomers, such as polyurethane, polyester, polyamide, olefin, and styrene elastomers; or mixtures thereof.

As shown inFIGS. 2 and 3, the puncture needle7is disposed in the distal portion of the cylindrical body2. The puncture needle7is configured to have the double ended needle71and the support member72that supports and fixes the double ended needle71.

The double ended needle71is a hollow needle tube, and has a sharp distal side needle tip at a distal end and also has a sharp proximal side needle tip at a proximal end. The double ended needle71can puncture a living body with the distal side needle tip and can pierce the sealing member11of the cylindrical body2with the proximal side needle tip.

A lumen part (hollow part) of the double ended needle71communicates with the cylindrical body2in a state where the sealing member11of the cylindrical body2is pierced with the proximal side needle tip, and functions as a flow path through which a liquid from the cylindrical body2passes.

The sealing member11of the cylindrical body2is pierced with the proximal side needle tip and the liquid is injected into the living body through the flow path of the double ended needle71after the living body is punctured to a predetermined depth from the skin using the distal side needle tip of the double ended needle71.

Note that the constituent materials of the double ended needle71are not particularly limited, and examples thereof include metallic materials such as stainless steel, aluminum or aluminum alloys, and titanium or titanium alloys.

The double ended needle71having such a configuration is mounted in the distal portion of the cylindrical body2through the support member72so as to be movable along the axial direction of the cylindrical body2. The support member72supports the double ended needle71with respect to the cylindrical body2so as to be movable along the axial direction thereof. The support member72forms a bottomed cylindrical shape. The double ended needle71is supported by and fixed to the bottom part of the support member72in a middle part of the double ended needle.

In addition, a plurality of elongated holes, which extend in the axial direction of the support member72and are opened in the proximal direction, are formed on the side wall of the support member72, and accordingly, a plurality of protruding pieces723are formed on the side wall of the support member72. Accordingly, it is possible to decrease or enlarge the diameter of the portion on the proximal side of the support member72by elastic deformation.

In addition, a rib724is formed in an inner peripheral portion of the proximal portion of each protruding piece723of the support member72. Each rib724is engaged with the rib231of the cylindrical body2on the proximal side, and therefore, it is possible to prevent the puncture needle7from being separated from the distal portion of the cylindrical body2.

In addition, each arm portion34of the administration restricting member3is positioned between two protruding pieces723, which are adjacent to each other, of the support member72. Accordingly, the puncture needle7is prevented from rotating in the circumferential direction during puncturing. Accordingly, it is possible to prevent coring when the proximal side needle tip of the double ended needle71penetrates the sealing member11.

As mentioned above, the puncture needle7is supported so as to be movable to the cylindrical body2along the axial direction through the support member72. Accordingly, the puncture needle7can take a separation state where the proximal side needle tip of the double ended needle71is separated from the sealing member11of the cylindrical body2as shown inFIGS. 2 and 3, and a pierced state where the sealing member11is pierced with the proximal side needle tip of the double ended needle71as shown inFIGS. 13 and 14. Accordingly, unintentional leaking of a liquid from the double ended needle71is prevented until the puncture needle7enters the pierced state.

As shown inFIGS. 2 and 5, the cover member6is disposed on the outer peripheral side of the cylindrical body2.

The cover member6is supported so as to be movable to an inner cylinder53, to be described later, of the operation member5in the axial direction. Accordingly, a living body is punctured to a predetermined depth from the skin using the distal side needle tip of the double ended needle71after a distal surface622of the cover member6is brought into contact with the living body.

The cover member6has five steps (positions) to be described later from before use to after use. The five positions include a first position (position (A)) (refer toFIGS. 1 to 3) at which the cover member6protrudes further on the distal side than the distal side needle tip of the double ended needle71in a state before use; a second position (position (B)) (refer toFIGS. 12 and 14) at which the cover member6is retreated in the proximal direction from the first position and the distal side needle tip of the double ended needle71is exposed from the distal end of the cover member6; and a third position (refer toFIGS. 15 and 17) at which the cover member6moves in the distal direction from the second position and protrudes further on the distal side than the distal side needle tip of the double ended needle71, and a safety mechanism is operated after the completion of the administration.

Note that, in the present embodiment, when the cover member6is at the first position, the distal surface622of the cover member6protrudes further on the distal side than the distal side needle tip of the double ended needle71to cover the distal side needle tip of the double ended needle71using the cover member6. Accordingly, the distal side needle tip of the double ended needle71is not exposed until the cover member6moves to the proximal side from the first position, and therefore, it is possible to prevent the skin of a user from being erroneously punctured with the distal side needle tip of the double ended needle71before the puncturing or the distal side needle tip from being damaged. In addition, when the cover member6is positioned at the second position, the distal side needle tip of the double ended needle71is exposed from the distal end of the cover member6.

Note that, when the cover member6is at the first position, the aforementioned puncture needle7enters the separation state where the puncture needle is positioned further on the proximal side than the distal portion of the cover member6. In contrast, when the cover member6moves to the second position, the cover member6presses and moves the double ended needle71(the double ended needle71together with the support member72) toward the proximal direction, and the proximal side needle tip of the double ended needle71pierces the sealing member11of the cylindrical body2and the distal side needle tip of the double ended needle71punctures a living body. In addition, when the cover member6is at the second position, the sealing member11is pierced with the proximal side needle tip of the double ended needle71, and the upper end surface inside the support member72and the distal surface of the cylindrical body2enter a state where they come into contact with each other.

The cover member6is configured to have a plate-shaped distal end wall part62that is disposed in the distal portion; and a side wall61that is erected in the proximal direction from the distal end wall part62, that is, the cover member is configured to have a member that forms a bottomed cylindrical shape. In addition, the cover member6has a distal surface622at the distal end.

An opening621is formed at the central portion of the distal end wall part62. As shown inFIGS. 12 to 14, when the cover member6is at the second position, the distal side needle tip of the double ended needle71protrudes (is exposed) from the opening621.

As shown inFIG. 5, the side wall61forms a cylindrical shape. Four spurs611are protrusively formed on the outer peripheral surface of the proximal portion of the side wall61toward the outside. The spurs611are disposed at substantially equiangular intervals along the circumferential direction of the side wall61. Each spur611is inserted into a groove532of the inner cylinder53to be described later and is movable along the groove532. Accordingly, the cover member6becomes movable in the axial direction with respect to the inner cylinder53.

A pair of cutout portions614that are disposed so as to face each other is formed in the proximal portion of the side wall61. Each cutout portion614is disposed between two adjacent spurs611, and in the configuration shown in the drawing, at an intermediate position between the two adjacent spurs611. Note that each cutout portion614is disposed at a position that is the same as a hook525of an outer plunger52, to be described later, in the axial direction, and accordingly, the cover member6and the hook525are designed not to interfere with each other when the cover member6moves.

As shown inFIGS. 2 and 3, a coil spring (compression coil spring)13is stored in the cover member6in a compressed state. The distal portion of the coil spring13is attached to the distal end wall part62inside the cover member6, and the proximal portion of the coil spring13is attached to the rib36of the administration restricting member3. In the compressed state in an unused state, the coil spring13is compressed by the weight loaded on the administration restricting member3. Note that the coil spring13may not be compressed if the distal portion of the coil spring13is attached to the distal end wall part62inside the cover member6and the proximal portion of the coil spring13is attached to the rib36of the administration restricting member3. For example, it is possible to bias the cover member6from the second position toward the first position (toward the distal direction) using the coil spring13. With the biasing force of such a coil spring13, the distal surface622of the cover member6can be made to protrude further on the distal side than the distal side needle tip of the double ended needle71until the liquid administration device10is completely used, and accordingly, it is possible to reliably prevent the erroneous puncturing due to the distal side needle tip.

Note that the constituent materials of the coil spring13are not particularly limited, and for example, metallic materials such as stainless steel can be used.

The gasket8is stored in the cylindrical body2so as to be slidable along the axial direction of the cylindrical body2. Note that the space surrounded by the gasket8and the cylindrical body2is filled with a liquid in advance. The liquid in the cylindrical body2can be pushed out from the double ended needle71in a state where the double ended needle communicates with the cylindrical body2, due to the gasket8moving toward the distal direction.

The outer shape of the gasket8is a flat or columnar shape, and two protruded parts81are formed in the outer peripheral part. Each protruded part81is separated along the axial direction of the gasket8. In addition, each of protruded part81forms a ring shape along the circumferential direction of the gasket8, and the outer diameter thereof is slightly larger than the inner diameter of the cylindrical body2in a natural state where external force is not applied. Accordingly, each of protruded part81can slide while being brought into close contact with the inner peripheral part of the cylindrical body2, and thus, it is possible to reliably retain the liquid-tightness and improve slidability.

In addition, a concave portion82, which interlocks an inner plunger51and the outer plunger52of the operation member5, to be described later, by inserting (fitting) the inner plunger51and the outer plunger52therein, is opened on the proximal surface of the gasket8.

As shown inFIGS. 1 to 3, the operation member5has the inner plunger51and the outer plunger52that interlock the gasket8on the proximal side and press the gasket8in the distal direction; the inner cylinder53; and an outer cylinder54. A plunger is constituted by the inner plunger51and the outer plunger52. In addition, the inner plunger51, the outer plunger52, the inner cylinder53, and the outer cylinder54are concentrically disposed in this order from the inside. In addition, the outer plunger52and the inner cylinder53are interlocked with each other. In addition, the inner cylinder53is movable only in the axial direction and is not rotatable around the axis, with respect to the outer cylinder54. In addition, the inner plunger51is rotatable only around the axis and is not movable in the axial direction, with respect to the outer plunger52. The operation member5is a member that performs pressing operation (discharging operation) to discharge a liquid in the cylindrical body2from the double ended needle71by moving the gasket8in the distal direction using the inner plunger51and the outer plunger52moving in the distal direction.

As shown inFIG. 6, the inner plunger51has a main body portion511having a longitudinal shape, that is, a rod shape; and a disk-shaped flange512that is provided at the proximal end of the main body portion511. The inner plunger is installed so as to be freely rotatable (rotationally movable) around the axis of the outer plunger52in a state where the main body portion511of the inner plunger is inserted into the outer plunger52.

Four spurs (slider portions)513are protrusively formed in the outer peripheral portion of the flange512toward the outside. The spurs513are disposed at substantially equiangular intervals along the circumferential direction of the flange512.

In addition, four claws514are protrusively formed in the outer peripheral portion of the flange512toward the distal side. The claws514are disposed at substantially equiangular intervals along the circumferential direction of the flange512. In addition, each claw514is disposed between two adjacent spurs513, and in the configuration shown in the drawing, at an intermediate position between the two adjacent spurs513. Each claw514is engaged with the flange522of the outer plunger52, and accordingly, the movement of the inner plunger51in the axial direction is inhibited, but the inner plunger51is rotatable around the axis, with respect to the outer plunger52.

In addition, a pair of rib rows515that are disposed so as to face each other when seen in a plan view is formed in the outer peripheral portion of the main body portion511. The rib rows515are respectively formed by a plurality of ribs516. Each rib516extends in the circumferential direction of the main body portion511and is formed in a part of the main body portion511in the circumferential direction when seen in a plan view.

In addition, the ribs516of the rib rows515are arranged in parallel at substantially equal intervals along the axial direction of the main body portion511. In other words, a concave portion517is formed by two adjacent ribs516therebetween in each rib row515and a plurality of concave portions517are arranged in parallel at substantially equal intervals along the axial direction of the main body portion511. Note that a second engagement portion of the pressing force transmission inhibiting mechanism50is formed by the rib rows515.

As shown inFIG. 7, the outer plunger52has a main body portion521having a cylindrical shape; and a disk-shaped flange522that is provided at the proximal end of the main body portion521. An opening that communicates with the lumen of the main body portion521is formed in the flange522.

In addition, four elastic arm portions523are protrusively formed on the distal side of the outer peripheral portion of the flange522in the distal direction. The arm portions523are disposed at substantially equiangular intervals along the circumferential direction of the flange522. Each claw524that outwardly protrudes is formed in the distal portion of each arm portion523. Each claw524is engaged with each of hole portions533by being inserted into each hole portion533to be described later from the inside on the proximal side of the inner cylinder53and the outer plunger52and the inner cylinder53are interlocked with each other.

Note that the method of interlocking the outer plunger52and the inner cylinder53is not limited thereto, and examples thereof include adhesion using adhesives, solvents, or the like; and weldings such as heat-welding, high frequency welding, and ultrasonic welding.

In addition, a pair of hooks525that are disposed so as to face each other is protrusively formed in the outer peripheral portion of the proximal portion of the main body portion521of the outer plunger52toward the outside. The shape of each hook525is not particularly limited, but in the configuration of the drawing, the shape thereof forms an L shape.

In addition, a pair of elongated holes526that are disposed so as to face each other is formed in the main body portion521over the distal portion from the central portion of the main body portion. Each elongated hole526extends along the axial direction. The main body portion521of the outer plunger52is inserted into the administration restricting member3and each spur32of the administration restricting member3is inserted into each elongated hole526. Accordingly, the administration restricting member3can relatively move to the outer plunger52and the inner plunger51in the axial direction. In addition, the rotation of the administration restricting member3around the axis with respect to the outer plunger52is inhibited.

In addition, an interlock portion527that is inserted into the concave portion82of the gasket8is formed in the distal portion of the main body portion521. The outer plunger52(operation member5) and the gasket8are interlocked by the interlock portion527being inserted into the concave portion82of the gasket8. Note that the method of fixing the gasket8to the main body portion521is not particularly limited thereto, and other examples thereof include a method of forming a male screw on the main body portion521, forming a female screw, which is screwed into the male screw, on the gasket8, and screwing both the screws together. Note that, in the present example, the operation member5is interlocked to the gasket8on the proximal side, but may not be interlocked therewith.

As shown inFIG. 4, the inner cylinder53has a cylindrical main body531that forms a cylindrical shape.

Four grooves531are formed on the inner peripheral surface of the cylindrical main body531(refer toFIG. 2). Grooves532extend along the axial direction thereof and are arranged in parallel at equiangular intervals along the circumferential direction. In addition, each groove53opens at the proximal end of the cylindrical main body531. In addition, the distal side of each groove53is blocked. Accordingly, the cover member6can be inhibited from being separated from the distal side of the inner cylinder53.

In addition, a pair of hole portions533that are disposed so as to face each other is formed in the proximal portion of the cylindrical main body531. Each hole portion533is disposed between two adjacent grooves532, and in the configuration shown in the drawing, at an intermediate position between the two adjacent grooves532.

In addition, four elastic protruding pieces (biasing mechanisms)534are protrusively formed at the distal end of the cylindrical main body531toward the distal side. The protruding pieces534are disposed at substantially equiangular intervals along the circumferential direction of the cylindrical main body531. In addition, the distal portion of each protruding piece534is positioned further on the outer peripheral side than the proximal portion. Note that a biasing mechanism (biasing portion), which biases the outer cylinder54with respect to the inner plunger51(plunger) toward the proximal direction, is formed by these protruding pieces534.

In addition, four elastic protruding pieces534are protrusively formed at the distal end of the cylindrical main body531toward the distal side. The protruding pieces534are disposed at substantially equiangular intervals along the circumferential direction of the cylindrical main body531. In addition, each protruding piece534is disposed between two adjacent protruding pieces534.

As shown inFIGS. 1 to 3, the outer cylinder54is disposed on the proximal side and the outer peripheral side of the inner plunger51, the outer plunger52, and the inner cylinder53.

The outer cylinder54is configured to have a plate-shaped proximal end wall part542that is disposed in the proximal portion; and a side wall541that is erected in the distal direction from the proximal end wall part542, that is, the outer cylinder is configured to have a member that forms a bottomed cylindrical shape. The outer cylinder54functions as a grip portion when gripping the operation member5.

In addition, four inclined grooves (cam grooves)544, as inclined rail portions, and four linear grooves543into which the four spurs513of the inner plunger51are inserted are formed on the inner peripheral surface of the side wall541of the outer cylinder54. The spurs513relatively move along the inclined grooves544. In the present embodiment, each inclined groove544and each linear groove543are formed so as to penetrate the side wall541in the present embodiment. However, the present invention is not limited thereto and they may not penetrate the side wall541. Note that the inclined grooves544are the same as each other and the linear grooves543are the same as each other. Therefore, one inclined groove544and one linear groove543will be representatively described below.

The linear groove543is formed in a linear shape in the axial direction of the outer cylinder54. In addition, the inclined groove544is formed so as to be inclined at a predetermined angle with respect to the axis of the outer cylinder54. In addition, the inclined groove544is formed to be shorter than one turn. The proximal portion of the linear groove543and the distal portion (left end portion inFIG. 1) of the inclined groove544communicate with each other.

When the outer cylinder54moves in the axial direction, the inner plunger51is rotated to the right side inFIG. 1with respect to the outer cylinder54at a predetermined angle due to the inclined groove544and the spur513of the inner plunger51. More specifically, the inner plunger51rotates with respect to the outer cylinder54, the inner cylinder53, and the outer plunger52. Note that a rotary mechanism (rotary portion), in which an engagement state or a released state can be selected by relatively rotating the spurs32of the administration restricting member3and the concave portion517of the inner plunger51around the central axis of the structure1, is constituted by the inclined groove544of the outer cylinder54and the spur513of the inner plunger51.

Here, in an unused state (initial state) shown inFIGS. 1 to 3, the spur513is positioned in the distal portion of the inclined groove544. In this state, the rib row515of the inner plunger51is positioned at a position of the elongated hole526of the outer plunger52and the spur32of the administration restricting member3is engaged with the concave portion517between two adjacent ribs516. Accordingly, the movement of the operation member5to the cylindrical body2in the distal direction is inhibited.

As shown inFIGS. 9 to 11, when the outer cylinder54moves to the inner cylinder53in the distal direction, the inner plunger51rotates to the right side inFIG. 9with respect to the outer cylinder54, the inner cylinder53, and the outer plunger52and the spur513moves to the proximal portion of the inclined groove544, due to the inclined groove544and the spur513. In this state, the rib row515of the inner plunger51is positioned at a position (deviated position) that is retreated from the position of the elongated hole526of the outer plunger52in the circumferential direction, and the engagement between the spur32of the administration restricting member3and the concave portion517is released. Accordingly, the operation member5can move to the cylindrical body2in the distal direction.

In addition, eight elastic arm portions545are protrusively formed in the inner peripheral portion of the distal portion of the side wall541in the distal direction. The arm portions545are disposed along the circumferential direction of the side wall541. Each claw546that inwardly protrude is formed in the distal portion of each arm portion545. Each arm portion545and each claw546are disposed between the adjacent protruding piece534and protruding piece535of the inner cylinder53, and the separation of the inner cylinder53from the outer cylinder54is inhibited by each claw546being engaged with the distal portion of the inner cylinder53.

The pressing mechanism40has a function of generating pressing force for pressing the gasket8, that is, a function of generating pressing force for pressing the gasket8through the inner plunger51and the outer plunger52of the operation member5. In the present embodiment, the pressing mechanism40is configured to have a pair of coil springs (extension coil springs: second biasing members)401. The proximal portion of each coil spring401is supported by the hook525of the outer plunger52and the distal portion thereof is supported by the hook33of the administration restricting member3, in an extended state. Accordingly, each coil spring401biases the structure1and the operation member5in a direction approaching each other. That is, each coil spring401generates pressing force for pressing the gasket8in the distal direction through the inner plunger51and the outer plunger52of the operation member5. Accordingly, it is possible to easily move the operation member5in the distal direction.

Note that the constituent material of the coil spring401is not particularly limited, and for example, it is possible to use the same material as that of the constituent material of the coil spring13.

The pressing force transmission inhibiting mechanism50has a function of inhibiting transmission of force of the coil spring401(pressing mechanism40) to the gasket8in the middle of the pressing operation. In addition, the pressing force transmission inhibiting mechanism50has the aforementioned function of inhibiting the transmission of the pressing force of the pressing mechanism40to the gasket8even in the unused state (initial state). In addition, the pressing force transmission inhibiting mechanism50has a function of changing the state of the pressing mechanism40from a state in which the pressing force of the pressing mechanism40is inhibited from being transmitted to the gasket8to a state where the pressing force is transmitted to the gasket8. In the present embodiment, the pressing force transmission inhibiting mechanism50is constituted by each spur32of the administration restricting member3and each rib row515of the inner plunger51, and can take an engagement state in which transmission of pressing force of the pressing mechanism40to the gasket8is inhibited in the middle of the pressing operation due to the engagement between the spur32of the administration restricting member3and the concave portion517of the inner plunger51, and a released state in which the pressing force of the pressing mechanism40is transmitted to the gasket8by release of the engagement state. Note that the action of the pressing force transmission inhibiting mechanism50will be described in the description of a method of using the liquid administration device10to be described later.

Next, the method of using the liquid administration device10and an operation state in use of the liquid administration device will be described with reference toFIGS. 1 to 3 and 9 to 20.

[1] As shown inFIGS. 1 to 3, the liquid administration device10in an unused state (initial state) is prepared. In the liquid administration device10in the unused state, the cover member6covers the distal side needle tip of the double ended needle71at a first position. Note that in the unused state, a state is maintained in which the distal side needle tip of the double ended needle71is covered by the cover member6due to the biasing force of the coil spring13. Accordingly, erroneous puncturing due to the distal side needle tip of the double ended needle71can be reliably prevented.

In addition, in the puncture needle7, the proximal side needle tip of the double ended needle71is separated from the sealing member11of the cylindrical body2, and does not pierce the sealing member11yet. Accordingly, it is possible to maintain the liquid in an aseptic state until administration of the drug solution starts.

In addition, the spur513of the inner plunger51is positioned in the distal portion of the inclined groove544of the outer cylinder54.

In addition, the rib row515of the inner plunger51is positioned at a position of the elongated hole526of the outer plunger52and the spur32of the administration restricting member3is engaged with the concave portion517between the two adjacent ribs516. Accordingly, the movement of the operation member5to the structure1(cylindrical body2) in the distal direction is inhibited.

[2] Next, as shown inFIGS. 9 to 11, the operation member5of the liquid administration device10in the unused state is gripped, the distal end wall part62of the cover member6is attached to a living body, and the operation member5is pressed toward the distal direction.

Accordingly, the outer cylinder54moves to the inner cylinder53in the distal direction; the inner plunger51rotates to the right side inFIG. 9with respect to the outer cylinder54, the inner cylinder53, and the outer plunger52due to the inclined groove544and the spur513; and the spur513moves to the proximal portion of the inclined groove544. In this state, the rib row515of the inner plunger51is positioned at a position (deviated position) that is retreated from the position of the elongated hole526of the outer plunger52in the circumferential direction, and the engagement between the spur32of the administration restricting member3and the concave portion517is released. Accordingly, the operation member5can move to the cylindrical body2in the distal direction.

[3] Next, as shown inFIGS. 12 to 14, when the operation member5is further continuously pressed toward the distal direction, the cover member6moves to the operation member5and the structure1in the proximal direction, that is, from the first position to the second position against the biasing force of the coil spring13.

At this time, the distal side needle tip of the double ended needle71protrudes from the opening621of the distal end wall part62of the cover member6and puncturing of a living body with the distal side needle tip is performed. In addition, the distal end wall part62presses the support member72of the puncture needle7toward the proximal direction. Accordingly, it is possible to pierce the sealing member11of the cylindrical body2with the proximal side needle tip of the double ended needle71, and thus, the double ended needle71puncturing the living body communicates with the cylindrical body2.

The engagement between the spur32of the administration restricting member3and the concave portion517is released, and therefore, the operation member5moves in the distal direction due to the biasing force of the coil spring401. Accordingly, the gasket8can move toward the distal direction. That is, the aforementioned pressing operation is performed, and therefore, it is possible to perform administration of a liquid. The gasket8is attached to the bottom part22of the cylindrical body2, and the administration of a liquid is completed.

At this time, the spur513of the inner plunger53is positioned in the proximal portion of the inclined groove544.

[4] Next, as shown inFIGS. 15 to 17, the pressing of the operation member5toward the distal direction is stopped; the distal end wall part62of the cover member6is separated from the living body; and the double ended needle71is removed from the living body.

Accordingly, the cover member6moves in the distal direction, that is, to the fifth position due to the biasing force of the coil spring13, and the distal side needle tip of the double ended needle71is covered with the cover member. In this manner, the cover member6and the coil spring13function as a safety mechanism that prevents needle piercing accidents after use.

In addition, at this time, the outer cylinder54moves to the inner cylinder53in the proximal direction due to the biasing force of the protruding piece534of the inner cylinder53; the inner plunger51rotates to the left side inFIG. 15with respect to the outer cylinder54, the inner cylinder53, and the outer plunger52due to the inclined groove544and the spur513; and the spur513moves to the distal portion of the inclined groove544. In this state, the rib row515of the inner plunger51is positioned at a position of the elongated hole526of the outer plunger52and the spur32of the administration restricting member3is engaged with the concave portion517.

[5] Here, during the administration of a liquid, in some cases, it is necessary to temporarily suspend the administration of the liquid when, for example, the pain due to the liquid is strong or the like. In this case, as shown inFIGS. 18 to 20, the pressing of the operation member5toward the distal direction is stopped; the distal end wall part62of the cover member6is separated from the living body; and the double ended needle71is removed from the living body. Alternately, the operation member5is slightly moved in the proximal direction or the pressing force is weakened.

Accordingly, the outer cylinder54moves to the inner cylinder53in the proximal direction due to the biasing force of the protruding piece534of the inner cylinder53; the inner plunger51rotates to the left side inFIG. 18with respect to the outer cylinder54, the inner cylinder53, and the outer plunger52due to the inclined groove544and the spur513; and the spur513moves to the distal portion of the inclined groove544. In this state, the rib row515of the inner plunger51is positioned at a position of the elongated hole526of the outer plunger52; the spur32of the administration restricting member3is engaged with the concave portion517; and the transmission of the biasing force of the coil spring401to the gasket8is inhibited (engagement state). That is, the positional relationship between the structure1and the operation member5in the central axis direction of the structure1is fixed and the movement of the operation member5to the structure1(cylindrical body2) in the distal direction is inhibited, and accordingly, it is possible to prevent a liquid from discharging from the distal end of the double ended needle71.

Then, the operation of pressing the operation member5toward the distal direction is restarted after, for example, the pain disappears. Accordingly, the outer cylinder54moves to the inner cylinder53in the distal direction; the inner plunger51rotates to the right side inFIG. 18with respect to the outer cylinder54, the inner cylinder53and the outer plunger52and the spur513moves to the proximal portion of the inclined groove544, due to the inclined groove544and the spur513; the rib row515of the inner plunger51moves to a position that is retreated from the position of the elongated hole526of the outer plunger52in the circumferential direction; the engagement between the spur32of the administration restricting member3and the concave portion517is released; the biasing force of the coil spring401is transmitted to the gasket8; and the administration of a liquid is restarted (released state).

Note that the rib row515has a plurality of ribs516that are provided in parallel in the axial direction of the inner plunger51, and therefore, the spur32of the administration restricting member3can be engaged with the concave portion517at a plurality of places in the axial direction of the inner plunger51. For this reason, it is possible to engage the spur32of the administration restricting member3with any concave portion517of the inner plunger51even at any position of the inner plunger51positioned in the axial direction.

As described above, according to the liquid administration device10that has the pressing mechanism40, it is possible to support the movement of the operation member5in the distal direction or to move the operation member5in the distal direction, using the biasing force of the coil spring401. Accordingly, it is possible to easily and reliably administer a liquid even for users who have difficulty in performing the pressing operation of the operation member5, for example, a person with a weak amount of force, a patient with rheumatism who has a pain or deformation in the finger, and the like.

For example, in a case where the pain due to a liquid is strong, when temporarily suspending the administration of a liquid, the movement of the operation member5to the cylindrical body2in the distal direction is inhibited by the engagement of the spur32of the administration restricting member3and the concave portion517of the inner plunger51. Accordingly, the transmission of the biasing force of the coil spring401to the gasket8is inhibited, and therefore, it is possible to prevent the liquid from discharging from the distal end of the double ended needle71. Furthermore, it is possible to restart the administration of a liquid by performing the pressing operation of the operation member5in the distal direction.

In addition, in the liquid administration device10, a state where the spur32of the administration restricting member3and the concave portion517of the inner plunger51are engaged with each other and a state where the engagement between the spur32and the concave portion517is released are taken through due to rotation of the inner plunger51by performing the pressing operation of the operation member5and stopping the pressing operation. When rotating the inner plunger51, there is no obstacle that inhibits the rotation of the inner plunger51, and therefore, resistance force during the pressing operation of the operation member5is relatively small. That is, in the liquid administration device10, the resistance force during the pressing operation of the operation member5is smaller than that in a case where a liquid administration device is configured such that a state where a spur and a concave portion is engaged and a state where the engagement is released are taken by a linear motion of a predetermined member. Accordingly, it is possible to easily perform the pressing operation and to easily administer a liquid.

Note that the pressing operation is set to be any operation of discharging a liquid from a needle tube using tensile force of coil spring or the like, or a sum of pressing force of a user, and tensile force of a coil spring or the like.

Second Embodiment

FIG. 21is a perspective view of an administration restricting member of a structure of a liquid administration device of the present invention in a second embodiment. Note that, hereinafter, the upper side is described as “proximal end (rear end)” or “upper (upward)”, the lower side is described as “distal end” or “lower (downward)”, and the vertical direction is described as “axial direction” or “longitudinal direction” inFIG. 21.

Hereinafter, in regard to the second embodiment, the difference between the second embodiment and the aforementioned first embodiment will be mainly described, and the description of the same matter will not be repeated.

A liquid administration device10of the second embodiment has a notification mechanism that notifies a user of information that discharging (administering) of a liquid is being performed. The notification mechanism has a vibration generating portion that notifies a user of a state of the discharging of a liquid through a pressing operation of an operation member5, by generating a sound (audible sound) and a vibration and the vibration generating portion will be described below.

As shown inFIG. 21, a pair of elastic spurs37that are disposed so as to face each other is protrusively formed in an inner peripheral portion of a proximal portion of a main body portion31of an administration restricting member3at a central axis (inside) of the main body portion31. The spurs37are respectively positioned between two spurs37, and in the configuration shown in the drawing, at an intermediate position between the two spurs37. Note that in the configuration shown in the drawing, the spur37has elasticity by making the thickness of the spur37thinner than that of the spur32. The vibration generating portion is configured to have each spur37and each rib row515of an inner plunger51.

Here, as described in the first embodiment, when the operation member5is pressed toward the distal direction by attaching a distal end wall part62of a cover member6to a living body, an outer cylinder54moves to an inner cylinder53in the distal direction. Moreover, the inner plunger51rotates to the right side inFIG. 9with respect to the outer cylinder54, the inner cylinder53, and an outer plunger52and a spur513moves to the proximal portion of an inclined groove544, due to the inclined groove544and the spur513(refer toFIGS. 9 to 11). In this state, the rib row515of the inner plunger51is positioned at a position (deviated position) that is retreated from the position of a elongated hole526of the outer plunger52in the circumferential direction, and the engagement between the spur32of the administration restricting member3and the concave portion517is released. Accordingly, the operation member5can move to the cylindrical body2in the distal direction.

In contrast, the rib row515of the inner plunger51and the spur37overlap each other when seen in a plan view. Accordingly, when the pressing operation is performed and the operation member5moves in the distal direction, the rib516of the rib row515climbs over the spur37through elastic deformation of the spur37. At that moment, a sound (audible sound) and a vibration (click feeling) are generated from the spur37.

A user feels the generated sound, and thus, it is possible to recognize that a liquid is being discharged. It is possible to recognize that the discharge of a liquid is completed when the sound is not generated. In addition, the generated vibration is transmitted to the outer cylinder54, and the user feels the vibration and the sound. Accordingly, the user can more reliably recognize a state of a liquid being discharged and a state of a liquid that has completely discharged. According to the liquid administration device10, the same effect as that in the aforementioned first embodiment can be obtained.

Hereinabove, the liquid administration device of the present invention has been described based on the embodiments shown in the drawings. However, the present invention is not limited thereto, and the configuration of each portion can be replaced with an arbitrary configuration that has an identical function. In addition, other arbitrary components may be added to the present invention.

In addition, the present invention may be obtained by combining two or more arbitrary configurations (characteristics) of each of the embodiments.

In addition, in the embodiments, the cylindrical body is filled with a liquid in advance. However, the present invention is not limited thereto, and for example, the cylindrical body may not be initially filled with a liquid and used by being filled with a liquid later.

In addition, in the embodiments, the first biasing member is a compression spring. However, the present invention is not limited thereto, and for example, the first biasing member may be a tensile spring or anything other than the spring.

In addition, in the embodiments, the second biasing member is a tensile spring. However, the present invention is not limited thereto, and for example, the second biasing member may be a compression spring or anything other than the spring.

In addition, in the present invention, the biasing mechanism (biasing portion) is not limited to the embodiments, and for example, may be a coil spring or the like.

In addition, in the present embodiment, the first engagement portion of the pressing force transmission inhibiting mechanism (pressing force transmission inhibiting portion) is provided in the structure and the second engagement portion is provided in the operation member. However, the present invention is not limited thereto, and for example, the first engagement portion of the pressing force transmission inhibiting mechanism may be provided in the operation member and the second engagement portion may be provided in the structure.

In addition, in the present embodiment, the puncture needle has a needle tube that is a double ended needle. However, the present invention is not limited thereto, and the puncture needle may have a needle tube without a needle tip on the proximal side. In this case, the needle tube communicates with the inner cylinder in advance (already in an unused state).

In addition, in the present embodiment, the inner cylinder53and the administration restricting member3are formed of different members from each other. However, the present invention is not limited thereto, and the inner cylinder and the administration restricting member may be integrally formed.

In addition, in the present embodiment, the inner plunger51and a plurality of ribs516(concave portions517) are integrally formed. However, the present invention is not limited thereto, and the inner plunger and a member having the plurality of ribs may be formed of different members to each other.

In addition, in the present invention, when the administration of a liquid is completed and the distal side needle tip of the double ended needle71is covered by the cover member6, a safety mechanism may be provided that maintains a state where the distal side needle tip of the double ended needle71is covered by the cover member6. The safety mechanism can be configured as, for example, a mechanism that inhibits a movement of the cover member6to the cylindrical body2in the proximal direction. The cover member6cannot move in the proximal direction due to the safety mechanism, and therefore, it is possible to prevent needle piercing after use.

The liquid administration device of certain embodiments of the present invention includes: a structure that includes a cylindrical body that has a bottom part in a distal portion and an opening in a proximal portion and can be filled with a liquid therein, a needle tube that is positioned in the distal portion of the cylindrical body and has a sharp needle tip at a distal end, and a proximal end of which is communicable with the inside of the cylindrical body, and a gasket that is installed in the cylindrical body and is slidable along an axial direction of the cylindrical body; an operation member that performs a pressing operation in which the liquid is discharged from the needle tube through the gasket; a pressing portion that generates a pressing force for pressing the gasket; and a pressing force transmission inhibiting portion that inhibits transmission of the pressing force to the gasket in the middle of the pressing operation.

According to embodiments of the present invention, it is possible to prevent a liquid from being discharged from a distal end of a needle tube when temporarily suspending administration of the liquid since the present invention has a pressing force transmission inhibiting portion. In addition, it is possible to restart the administration of the liquid that is once suspended. Accordingly, it is preferable to prevent the liquid from being wasteful or insufficient, and to administer a sufficient amount of the liquid to a living body. Therefore, the present invention has industrial applicability.