JP6665165B2 - Injection needle assembly and drug injection device - Google Patents

Description

  The present invention relates to an injection needle assembly and a drug injection device used for puncturing a needle tip from the surface of skin and injecting a drug into an upper layer of the skin.

  In recent years, human infection with bird flu has been reported, and there is a concern about a large amount of pandemic human-to-human transmission. Therefore, reserves of prepandemic vaccines that are likely to be effective against bird flu are being stored around the world. Further, in order to administer a prepandemic vaccine to a large number of humans, studies have been made to expand the production amount of the vaccine.

  The skin is composed of three parts: epidermis, dermis, and subcutaneous tissue. The epidermis is a layer of about 50 to 200 μm from the skin surface, and the dermis is a layer of about 1.5 to 3.5 mm following the epidermis. Influenza vaccines are generally administered subcutaneously or intramuscularly, and thus are administered to the lower layer of the skin or deeper.

  On the other hand, it is reported that administering the influenza vaccine to the upper layer of the skin where many immunocompetent cells are present as a target site can achieve the same ability to acquire immunity as subcutaneous or intramuscular administration even if the dosage is reduced. Have been. Therefore, by administering the prepandemic vaccine to the upper skin layer, the dose can be reduced, so that the prepandemic vaccine can be administered to more humans. The upper layer of the skin refers to the epidermis and dermis of the skin.

  As a method for administering a drug to the upper layer of the skin, various methods using a single needle, multiple needles, a patch, a gas, etc. have been reported. However, considering the stability, reliability, and production cost of administration, It is considered that a method using a single needle is most suitable as an administration method to the upper layer. The Mantoux method has long been known as a method of administering a vaccine to the upper layer of the skin using this single needle. In the Mantoux method, generally, a needle having a short beveled needle with a size of 26 to 27 gauge and having a short bevel is inserted into the skin at an angle of about 10 to 15 ° from about 2 to 5 mm, and about 100 μl of drug is administered. How to

  However, since the administration of the drug by the Mantoux method is difficult, the success rate depends on the skill of the doctor who performs the injection. It is difficult to administer the influenza vaccine by the Mantoux method, especially since children may move at the time of administration. Therefore, there is a need for the development of a device that can easily administer a vaccine to the upper layer of the skin.

  Patent Literature 1 describes an injection device for an upper layer of skin in which a limiter having a skin contact surface is connected to a needle hub. The limiter described in Patent Document 1 is provided around a needle tube and has a gap between the limiter and the needle tube. By defining the length (projection length) of the needle tube protruding from the surface of the limiter that comes into contact with the skin to be 0.5 to 3.0 mm, the medicine is to be administered into the skin.

JP 2001-137343 A

  However, in the injection device described in Patent Document 1, since the needle tip of the needle tube always projects from the surface of the limiter that comes into contact with the skin, the needle tip of the needle tube is used after administration of the drug or when disposing of the drug injection device. There is a problem that the puncture may be erroneously made by a person.

  An object of the present invention is to provide an injection needle assembly and a drug injection device capable of preventing a needle tip of a needle tube from being accidentally punctured by a user after administration of a drug or at the time of disposal, in consideration of the above problems. It is in.

In order to solve the above problems and achieve the object of the present invention, an injection needle assembly according to the present invention includes a needle tube having a needle tip that can puncture a living body, a needle hub that holds the needle tube, a protector, and a biasing member. And a contact piece provided on the protector, a retaining member, and a holding and releasing mechanism. The protector is movable to a first position where the needle tip of the needle tube is exposed and a second position where the protector covers the needle tip of the needle tube. The urging member urges the protector from the first position to the second position along the axial direction of the needle tube. The retaining member comes into contact with the contact piece when the protector moves to the second position. The holding and releasing mechanism detachably holds the protector at the first position .
The holding and releasing mechanism includes a holding member having a holding portion detachably engaged with the contact piece, and a regulating hole into which the holding portion is inserted and which reduces the diameter of an opening formed by the holding portion. A maintenance member. When the holding member comes out of the regulating hole, the engagement with the contact piece is released.

  Further, the drug injection device of the present invention includes an injection needle assembly and a syringe detachably attached to the injection needle assembly. For the injection needle assembly, the above-described injection needle assembly is used.

  According to the injection needle assembly and the medicine injection device of the present invention, it is possible to prevent the needle tip of the used needle tube from being punctured against the user's intention.

It is a perspective view showing the medicine injection device concerning a 1st embodiment of the present invention. It is a sectional view showing the medicine injection device concerning a 1st embodiment of the present invention. FIG. 2 is a cross-sectional view showing a state after puncturing in the drug injection device according to the first embodiment of the present invention. It is a sectional view showing a medicine injection device concerning a 2nd embodiment of the present invention. It is a top view showing a holding part and a holding release part in a medicine injection device concerning a 2nd embodiment of the present invention. It is a sectional view showing the state after puncture in the medicine injection device concerning a 2nd embodiment of the present invention.

Hereinafter, an embodiment of an injection needle assembly and a medicine injection device of the present invention will be described with reference to FIGS. In the drawings, common members are denoted by the same reference numerals. Further, the present invention is not limited to the following embodiments.
The description will be made in the following order.
1. First Embodiment 1-1. Configuration example of injection needle assembly and drug injection device 1-2. 1. How to use the drug injection device Example of the second embodiment

<1. First Embodiment>
1-1. Configuration Example of Injection Needle Assembly and Drug Injection Device First, an injection needle assembly and a drug according to a first embodiment of the present invention (hereinafter, referred to as “this example”) with reference to FIGS. The injection device will be described.
FIG. 1 is a perspective view showing a medicine injection device of the present example, and FIG. 2 is a cross-sectional view showing a syringe needle assembly of the present example.

  The drug injection device 1 is used to puncture the needle tip into the surface of the skin and inject the drug into the upper layer of the skin. As shown in FIG. 1, a medicine injection device 1 includes an injection needle assembly 2, a syringe 3 detachably mounted on the injection needle assembly 2, a pusher member 4, and a syringe holder for holding the syringe 3. And 5.

[Syringe]
The syringe 3 is a prefilled syringe that is pre-filled with a drug. The syringe 3 has a syringe main body 11, a discharge portion formed at one end in the axial direction of the syringe main body 11, a lock mechanism 12 provided at the discharge portion, and a gasket 13.

  The syringe body 11 is formed in a hollow substantially cylindrical shape. Further, a gasket 13 is slidably disposed in the cylindrical hole of the syringe body 11. The gasket 13 is formed in a substantially cylindrical shape, and is in close contact with the inner peripheral surface of the cylindrical hole of the syringe body 11 in a liquid-tight manner. The gasket 13 partitions the internal space of the syringe body 11 into two. A space in the syringe body 11 closer to the discharge portion than the gasket 13 is a liquid chamber 14 filled with the medicine. On the other hand, a plunger main body 16 of the pusher member 4 described later is inserted into a space on the other end side of the gasket 13 in the syringe main body 11.

  The material of the gasket 13 is not particularly limited, but is preferably made of an elastic material in order to improve the liquid tightness with the syringe body 11. Examples of the elastic material include various rubber materials such as natural rubber, isobutylene rubber, and silicone rubber, various thermoplastic elastomers such as olefin-based and styrene-based materials, and mixtures thereof.

  The outer diameter and the inner diameter of the syringe main body 11 are appropriately set according to the use of the medicine injection device 1 and the capacity of the medicine contained in the liquid chamber 14. For example, when the capacity of the medicine to be stored is 0.5 mL using a general-purpose high-speed filling machine, the inner diameter of the syringe main body 11 is set to 4.4 to 5.0 mm, and the outer diameter of the syringe main body 11 is set to 6. It is preferable to set it to 5 to 8.4 mm. When the capacity is 1 mL, it is preferable that the inner diameter of the syringe main body 11 is set to 6.1 to 9.0 mm and the outer diameter of the syringe main body 11 is set to 7.9 to 12.5 mm.

  Examples of the drug include, but are not limited to, various vaccines for preventing various infectious diseases such as influenza. Drugs other than vaccines include, for example, carbohydrate injections such as glucose, electrolyte correction injections such as sodium chloride and potassium lactate, vitamins, antibiotics injections, contrast agents, steroids, protease inhibitors Agents, fat emulsions, anticancer agents, anesthetics, heparin calcium, antibody drugs and the like.

  A flange 15 is formed at the other end of the syringe body 11 in the axial direction. The flange portion 15 is locked by a locking portion 5a provided on the syringe holder 5 described later. Further, at one end of the syringe body 11 in the axial direction, a discharge portion not shown in the figure is continuously formed.

  The discharge portion is formed in a substantially cylindrical shape coaxial with the syringe main body 11. The cylindrical hole of the discharge portion communicates with the cylindrical hole of the syringe body 11. The discharge portion is formed in a tapered shape whose diameter continuously decreases toward one end in the axial direction. When the injection needle assembly 2 is attached to the syringe 3, the distal end of the discharge unit comes into liquid-tight contact with an end surface of an elastic member 25 of the injection needle assembly 2 described later.

  The discharge unit is provided with a lock mechanism 12. The lock mechanism 12 is a luer lock unit that shows an example of a fixing mechanism. The lock mechanism 12 is formed in a cylindrical shape surrounding the discharge portion coaxially. The lock mechanism 12 has a circular inner periphery and a hexagonal outer periphery. A female screw portion is formed on the inner peripheral surface of the lock mechanism 12. The female screw portion is formed to be screwable with a male screw portion 52b provided on the injection needle assembly 2.

  Examples of the material of the syringe body 11 include polyvinyl chloride, polyethylene, polypropylene, cyclic polyolefin, polystyrene, poly- (4-methylpentene-1), polycarbonate, acrylic resin, acrylonitrile-butadiene-styrene copolymer, and polyethylene. Various resins such as polyester such as terephthalate, butadiene-styrene copolymer, and polyamide (for example, nylon 6, nylon 6.6, nylon 610, nylon 12) are exemplified. Among them, it is preferable to use a resin such as polypropylene, cyclic polyolefin, polyester, and poly- (4-methylpentene-1) in that molding is easy. In addition, it is preferable that the material of the syringe main body 11 is substantially transparent in order to secure the visibility inside.

  In the present embodiment, an example in which a prefilled syringe pre-filled with a drug is applied as the syringe 3 is described. However, the present invention is not limited to this, and a syringe in which a drug is not pre-filled in the syringe body may be applied. Good.

[Syringe holder]
Next, the syringe holder 5 will be described.
The syringe holder 5 is formed in a substantially cylindrical shape. The syringe holder 5 covers the outer peripheral surface of the syringe main body 11 and the outer peripheral surface of the lock mechanism 12 in the syringe 3. The syringe holder 5 is configured to be grippable by a user when attaching the injection needle assembly 2 to the syringe 3.

  A viewing window 18 is formed at one end of the syringe holder 5 in the axial direction. The viewing window 18 is provided at a position where the liquid chamber 14 of the syringe 3 can be viewed from the outside of the syringe holder 5 when the syringe 3 is mounted on the syringe holder 5. Thereby, even if the syringe holder 5 is attached to the syringe 3, the internal visibility can be ensured.

  At the other end of the syringe holder 5 in the axial direction, a holder flange 19 is formed. The holder flange 19 projects substantially vertically from a part of the outer peripheral surface of the syringe holder 5. By providing the holder flange 19, it is possible to prevent a finger gripping the syringe holder 5 from sliding toward the other end in the axial direction when the user grips the syringe holder 5 and administers a medicine. Can be. Further, when the medicine injection device 1 is placed on a desk or a table, it is possible to prevent the medicine injection device 1 from rolling.

  Further, a locking portion 5a is provided at an intermediate portion of the syringe holder 5 in the axial direction. The locking portion 5a is an opening penetrating the outer wall of the syringe holder 5. The flange portion 15 of the syringe 3 is locked to the locking portion 5a.

  By mounting the syringe holder 5 on the syringe 3, the diameter of the drug injection device 1 can be increased, and the drug injection device 1 can be easily gripped. Thereby, the operability when operating the pusher member 4 is improved.

[Presser member]
The pusher member 4 includes a plunger body 16, an operation unit 17 that operates the plunger body 16, and a pressing member 20 that presses a holding and maintaining unit 42 of the injection needle assembly 2 described below. The plunger body 16 is formed in a rod shape. The plunger body 16 is inserted into a cylindrical hole of the syringe body 11 from an opening formed at the other end in the axial direction of the syringe body 11. Then, one end of the plunger body 16 in the axial direction comes into contact with the gasket 13.

  The operation unit 17 is formed at the other end of the plunger body 16 in the axial direction. The operation unit 17 is formed in a substantially disk shape. When using the medicine injection device 1, the operation unit 17 is pressed by the user. As a result, one end of the plunger body 16 in the axial direction comes into contact with the gasket 13 and slides the gasket 13 toward the discharge portion.

  The pressing member 20 is formed in a rod shape. The pressing member 20 is connected to the other end in the axial direction of the plunger main body 16 via a connecting portion not shown in the drawing. The pressing member 20 has its axial direction extending substantially parallel to the axial direction of the plunger body 16. As a method of connection, the plunger body 16 is provided with a projection or a flange formed integrally with the plunger body 16 and has a method for connecting the connection portion of the pressing member 20 thereto, and a hole for inserting the plunger body 16 therethrough. A method of connecting the connecting portion of the pressing member 20 to a disk-shaped object whose movement in the direction of the operation unit 17 due to such a protrusion or a flange-shaped object is restricted.

  The pressing member 20 is disposed in a gap formed between the cylindrical hole of the syringe holder 5 in the syringe holder 5 and the syringe main body 11 of the syringe 3. One end of the pressing member 20 in the axial direction protrudes from one end of the syringe holder 5 in the axial direction, and faces a holding / maintaining portion 42 provided in the injection needle assembly 2 described later. When the operation unit 17 is pressed by the user, the pressing member 20 moves along with the plunger body 16 in the axial direction.

  Further, as the material of the pusher member 4, various resins listed as the material of the syringe body 11 can be applied.

[Injection needle assembly]
Next, the injection needle assembly 2 will be described.
As shown in FIGS. 1 and 2, the injection needle assembly 2 includes a hollow needle tube 21 and a needle hub 22 holding the needle tube 21.

[Needle tube]
As shown in FIG. 2, the needle tube 21 has a size of 26 to 33 gauge (outer diameter of 0.2 to 0.45 mm) according to ISO medical needle tube standard (ISO 9626: 1991 / Amd. 1: 2001 (E)). And preferably 30 to 33 gauge. Note that a needle smaller than 33 gauge may be used.

  At one end of the needle tube 21, a needle tip 21a having a blade surface is provided. Hereinafter, the other end of the needle tube 21 opposite to the needle tip 21a is referred to as a “base end”. The axial length of the needle tube 21 on the blade surface (hereinafter, referred to as “bevel length”) may be 1.4 mm (adult) or less, which is the thinnest thickness of the upper skin layer described later, and is 33. The bevel length when the short bevel is formed in the needle tube of the gauge may be about 0.5 mm or more. That is, the bevel length is preferably set in the range of 0.5 to 1.4 mm.

  Further, the bevel length is even better if the thinnest thickness of the upper skin layer is 0.9 mm (child) or less, that is, the bevel length is in the range of 0.5 to 0.9 mm. In addition, the short bevel refers to a blade surface that is generally used for an injection needle and forms an angle of 18 to 25 with respect to the longitudinal direction of the needle.

  As a material of the needle tube 21, for example, stainless steel can be cited, but it is not limited to this, and aluminum, aluminum alloy, titanium, titanium alloy and other metals can be used. Further, the needle tube 21 can use not only a straight needle but also a tapered needle having at least a part tapered. As for the tapered needle, the proximal end has a larger diameter than the distal end of the needle, and an intermediate portion thereof may have a tapered structure. Further, the cross-sectional shape of the needle tube 21 may be not only a circle but also a polygon such as a triangle.

[Needle hub]
The needle hub 22 includes a first member 23 that holds the needle tube 21, a second member 24 into which the discharge portion of the syringe 3 is fitted, an elastic member 25, a protector 26, a biasing member 27, and a holding member 41. , And a holding and maintaining unit 42. The first member 23 and the second member 24 are formed as separate members. Examples of the material of the first member 23 and the second member 24 include synthetic resins such as polycarbonate, polypropylene, and polyethylene.

  The first member 23 includes a base portion 31, an adjusting portion 32, a stabilizing portion 33, a guide portion 34, and a support portion 37. The base portion 31 is formed in a substantially columnar shape. An accommodation recess 36 is formed in the base portion 31. The accommodation recess 36 is formed to be substantially cylindrically recessed from one end of the base portion 31 in the axial direction to the other end. An entire end of the base portion 31 in the axial direction is open. The accommodation recess 36 is provided with a support portion 37.

  The support portion 37 is provided at the center of the bottom surface 36 a of the housing recess 36, and protrudes from the bottom surface 36 a of the housing recess 36 toward one axial side of the base portion 31. The support part 37 is formed in a substantially columnar shape.

  The adjusting portion 32 is continuously provided on one end surface of the supporting portion 37 in the axial direction. The adjusting portion 32 is formed of a columnar projection projecting in the axial direction of the supporting portion 37. The axis of the adjusting section 32 coincides with the axis of the base section 31 and the supporting section 37.

  Further, two first openings 38, 38 facing each other are formed in the side wall of the base 31. The two first openings 38, 38 penetrate the side wall of the base 31 to the housing recess 36. In the two first openings 38, a holding / maintaining portion 42 described later is slidably inserted along the axial direction of the base portion 31.

  A through hole 39 through which the needle tube 21 penetrates is provided in the axis of the base portion 31, the support portion 37, and the adjustment portion 32. The base portion 31 is provided with an injection hole 44 for injecting an adhesive into the through hole 39. The injection hole 44 is opened on the outer circumferential surface on the other side in the axial direction than the housing recess 36 in the base portion 31, and communicates with the through hole 39. That is, the needle tube 21 is fixed to the base portion 31 and the support portion by the adhesive injected from the injection hole 44 into the through hole 39.

  The proximal end side of the needle tube 21 protrudes from the other end surface 31 a in the axial direction of the base portion 31. The base portion 31 is inserted into the second member 24 from the end face 31 a, and the base end side of the needle tube 21 is inserted into the insertion hole of the elastic member 25. The end surface 31a of the base portion 31 faces the end surface of the elastic member 25.

  A connection piece 35 is provided on the outer peripheral surface of the base portion 31. The connection piece 35 is formed at one end of the base portion 31 in the axial direction as a ring-shaped flange portion projecting outward in the radial direction of the base portion 31. The connection piece 35 has flat surfaces 35 a and 35 b that face each other in the axial direction of the base portion 31. The second member 24 is connected to the flat surface 35b of the connection piece 35. The distal end of the connection piece 35 serves as a guide 34. The guide section 34 will be described later in detail.

  The end surface of the adjusting portion 32 is a needle projecting surface 32a from which the needle tip 21a side of the needle tube 21 projects. The needle projecting surface 32a is formed as a plane orthogonal to the axial direction of the needle tube 21. The needle protruding surface 32a defines the depth at which the needle tube 21 is punctured by contacting the surface of the skin when the needle tube 21 is punctured into the upper layer of the skin. That is, the depth at which the needle tube 21 is punctured into the upper layer of the skin is determined by the length of the needle tube 21 projecting from the needle projecting surface 32a (hereinafter, referred to as “projection length L”) (see FIG. 3).

  The thickness of the upper skin layer corresponds to the depth from the surface of the skin to the dermis layer, and is generally in the range of 0.5 to 3.0 mm. Therefore, the projection length L of the needle tube 21 can be set in the range of 0.5 to 3.0 mm.

  The administration site of the influenza vaccine is generally the deltoid muscle. Therefore, the thickness of the upper layer of the deltoid muscle was measured for 19 children and 31 adults. This measurement was performed by imaging the upper layer of the skin with high ultrasonic reflectivity using an ultrasonic measuring device (NP60R-UBM, high-resolution echo for small animals, Nepagene). Since the measured values had a lognormal distribution, the range of MEAN ± 2SD was determined by geometric mean.

  As a result, the thickness of the upper skin layer in the deltoid muscle of a child was 0.9 to 1.6 mm. The thickness of the upper skin layer of the deltoid muscle in adults is 1.4 to 2.6 mm at the distal part, 1.4 to 2.5 mm at the central part, and 1.5 to 2.5 mm at the proximal part. Was. From the above, it was confirmed that the thickness of the upper skin layer of the deltoid muscle was 0.9 mm or more in children and 1.4 mm or more in adults. Therefore, it is preferable to set the protruding length L of the needle tube 21 in the range of 0.9 to 1.4 mm during the injection in the upper layer of the deltoid muscle.

  By setting the protruding length L in this manner, the blade surface of the needle tip 21a can be positioned in the upper layer of the skin. As a result, the needle hole (drug outlet) opened in the blade surface is located in the upper layer of the skin, regardless of the position in the blade surface. Even when the drug outlet is located in the upper layer of the skin, if the needle tip 21a is stabbed deeper than the upper layer of the skin, the drug flows into the subcutaneous tissue from between the side surface of the end of the needle tip 21a and the cut skin. Therefore, it is important to ensure that the blade surface is in the upper layer of the skin.

  When used for administration to the upper layer of the skin, it is difficult to reduce the bevel length to 1.0 mm or less with a needle tube thicker than 26 gauge. Therefore, in order to set the protruding length L of the needle tube 21 in a preferable range (0.9 to 1.4 mm), it is preferable to use a needle tube thinner than 26 gauge.

  The needle protruding surface 32a of the adjusting portion 32 is formed so that the distance S from the peripheral edge to the outer peripheral surface of the needle tube 21 is 1.4 mm or less, and is preferably formed in a range of 0.3 to 1.4 mm. The distance S from the peripheral edge of the needle protruding surface 32a to the peripheral surface of the needle tube 21 is set in consideration of pressure applied to a blister formed by administering a drug to the upper layer of the skin. That is, the needle protruding surface 32a is set to a size that is sufficiently smaller than the blister formed in the upper layer of the skin and does not hinder the formation of the blister. As a result, even if the needle projecting surface 32a presses the skin around the needle tube 21, it is possible to prevent the administered medicine from leaking.

  The stabilizer 33 is formed in a cylindrical shape protruding from the flat surface 35 a of the connection piece 35. The needle tube 21, the adjustment unit 32, and a protector 26 described later are arranged in the cylindrical hole of the stabilizer 33. That is, the stabilizing portion 33 is formed in a cylindrical shape that covers the periphery of the adjuster 32 through which the needle tube 21 penetrates and the protector 26, and is provided radially away from the needle tip 21 a of the needle tube 21.

  The end surface 33a of the stabilizer 33 is located closer to the base end of the needle tube 21 than the needle projecting surface 32a of the adjustment unit 32. When the living body is punctured with the needle tip 21a of the needle tube 21, the needle protruding surface 32a first comes into contact with the surface of the skin, and then the end surface 33a of the stabilizer 33 comes into contact with the surface of the skin. At this time, the medicine injection device 1 is stabilized by the end surface 33a of the stabilizer 33 being in contact with the skin, and the needle tube 21 can be maintained in a posture substantially perpendicular to the skin.

  In addition, even if the end surface 33a of the stabilizing part 33 is located on the same plane as the needle projecting surface 32a, or is located on the needle tip 21a side of the needle tube 21 beyond the needle projecting surface 32a, the needle tube 21 is Can be maintained in a substantially vertical posture. Considering the swelling of the skin when the stabilizer 33 is pressed against the skin, the axial distance between the end surface 33a of the stabilizer 33 and the needle protruding surface 32a is preferably set to 1.3 mm or less.

  The inner diameter d of the stabilizer 33 is set equal to or larger than the diameter of a blister formed on the skin. Specifically, the distance T from the inner wall surface of the stabilizing portion 33 to the periphery of the needle protruding surface 32a is set to be in a range of 4 mm to 15 mm. Thus, pressure is not applied to the blister from the inner wall surface of the stabilizer 33, and it is possible to prevent the formation of the blister from being hindered.

  There is no particular upper limit as long as the distance T from the inner wall surface of the stabilizer 33 to the needle protruding surface 32a is 4 mm or more. However, when the distance T is increased, the outer diameter of the stabilizing portion 33 increases, so that when the needle tube 21 is punctured into a thin arm like a child, it is difficult to bring the entire end face 33a of the stabilizing portion 33 into contact with the skin. . For this reason, it is preferable that the distance T is set to a maximum of 15 mm in consideration of the thinness of a child's arm.

  If the distance S from the needle projection surface 32a to the outer peripheral surface of the needle tube 21 is 0.3 mm or more, the adjustment unit 32 does not enter the skin. Accordingly, considering the distance T (4 mm or more) from the inner wall surface of the stabilizing portion 33 to the periphery of the needle projecting surface 32a and the diameter (about 0.3 mm) of the needle projecting surface 32a, the inner diameter d of the stabilizing portion 33 is 9 mm or more. Can be set to

  The shape of the stabilizing portion 33 is not limited to a cylindrical shape, and may be formed in, for example, a rectangular cylinder or a hexagonal prism having a cylindrical hole at the center.

  The guide portion 34 is a portion on the distal end side of the connection piece 35 that is located outside the first member 23 in the radial direction with respect to the stable portion 33. The guide portion 34 has a contact surface 34a that contacts the skin. The contact surface 34a is a part of the flat surface 35a of the connection piece 35, and is a plane substantially parallel to the end surface 33a of the stabilizer 33. By pressing the stabilizing portion 33 until the contact surface 34a of the guide portion 34 comes into contact with the skin, the force by which the stabilizing portion 33 and the needle tube 21 press the skin can always be maintained at a predetermined value or more. Thereby, the portion (corresponding to the protruding length L) of the needle tube 21 protruding from the needle protruding surface 32a is reliably punctured into the skin.

  The distance Y from the contact surface 34a of the guide portion 34 to the end surface 33a of the stabilizing portion 33 (hereinafter referred to as "guide portion height") is determined by the needle tube 21 and the stabilizing portion 33 pressing the skin with an appropriate pressing force to puncture the skin. Its length is set so that it can be. The appropriate pressing force of the needle tube 21 and the stabilizing portion 33 is, for example, 3 to 20N. Thereby, the guide portion 34 guides the pressing force on the skin by the needle tube 21 and the stabilizing portion 33, so that the needle tip 21a of the needle tube 21 can be reliably positioned in the upper layer of the skin, and gives the user a sense of security. be able to.

  The height Y of the guide portion is appropriately determined based on the inner diameter d of the stabilizer 33 and the length X from the distal end surface of the guide portion 34 to the outer peripheral surface of the stabilizer 33 (hereinafter referred to as “guide portion length”). You. For example, when the inner diameter d of the stabilizer 33 is 12 mm and the length X of the guide portion is 3.0 mm, the height Y of the guide portion is set in the range of 2.3 to 6.6 mm.

  Next, the protector 26 will be described. As shown in FIGS. 1 and 2, before the needle tube 21 is punctured into the skin, the protector 26 covers the periphery of the adjustment part 32 through which the needle tube 21 penetrates. Further, the needle tip 21a side of the needle tube 21 protrudes from the distal end surface 26a at one end in the axial direction of the protector 26, and the needle tip 21a of the needle tube 21 is exposed. The position of the protector 26 at this time is defined as a first position.

  The protector 26 is formed in a cylindrical shape. The protector 26 is supported by the support portion 37 and the retaining member 43 so as to be movable in these axial directions (the axial direction of the needle tube 21). A part of the protector 26 on the other side in the axial direction is inserted into a space 40 formed between the accommodation recess 36 and the support portion 37. In a state after the needle tube 21 has been punctured into the skin, the protector 26 covers the adjustment part 32 and the periphery of the needle tip 21a of the needle tube 21 (see FIG. 3). The position of the protector 26 at this time is defined as a second position.

  A contact piece 29 is provided on the side of the protector 26 opposite to the needle tip 21a of the needle tube 21, that is, on the other end in the axial direction. The contact piece 29 is formed as a ring-shaped flange portion protruding radially outward from the outer peripheral surface of the protector 26. Further, an inclined surface 29 a is provided on the outer edge of the contact piece 29 on the outer side in the radial direction. The inclined surface 29 a is provided at a corner of the outer edge of the contact piece 29 on the needle tip 21 a side of the needle tube 21. The inclined surface 29a is formed in a tapered shape whose diameter continuously decreases from one side to the other side in the axial direction.

  A holding member 41 is arranged on the other side of the protector 26 in the axial direction.

  The shape of the protector 26 is not limited to a cylindrical shape. For example, the protector 26 may be formed in a rectangular cylindrical shape such as a square pillar or a hexagonal pillar having a cylindrical hole at the center. Further, an example in which the contact piece 29 is formed as a ring-shaped flange portion has been described, but the present invention is not limited to this. For example, a plurality of protrusions protruding outward from the outer peripheral surface of the protector 26 in the radial direction. It may be formed as.

  The urging member 27 is disposed in a space 40 formed in the housing recess 36, and is interposed between the other end surface of the protector 26 in the axial direction and the bottom surface 36 a of the housing recess 36. The urging member 27 is arranged so as to cover the periphery of the outer peripheral surface of the support portion 37. The biasing member 27 is a compression coil spring, and biases the protector 26 from the first position toward the second position, that is, toward the needle tip 21a of the needle tube 21.

  The urging force of the urging member 27 is set smaller than an appropriate pressing force when the needle tube 21 punctures the skin, and is set to, for example, 3N or less. Accordingly, when the needle tube 21 is punctured into the skin, the urging force of the urging member 27 does not prevent the needle tip 21a of the needle tube 21 from being positioned in the upper layer of the skin. The tip 21a can be located in the upper layer of the skin.

  In this example, an example in which a compression coil spring is applied as the urging member 27 has been described, but the present invention is not limited to this. The urging member may be any elastic member that elastically deforms when a predetermined pressing force is applied. For example, various other spring members such as a leaf spring, sponge, gel, and rubber members can be applied.

  Next, the holding member 41 will be described. The holding member 41 has a cylindrical portion 45 formed in a substantially cylindrical shape, and a plurality of holding portions 46. The holding member 41 is arranged in the housing recess 36. Further, the cylindrical portion 45 is fixed to the bottom surface 36 a of the housing recess 36. The holding member 41 is arranged so as to cover the periphery of the other side in the axial direction of the support portion 37. A plurality of holding portions 46 are continuously formed on one side of the cylindrical portion 45 in the axial direction.

  The plurality of holding portions 46 are provided on one end surface of the cylindrical portion 45 in the axial direction at predetermined intervals along the circumferential direction. The plurality of holding portions 46 project from the one end surface in the axial direction of the cylindrical portion 45 into a substantially flat plate shape. Further, the plurality of holding portions 46 are formed in a tongue piece shape, and have elasticity.

  The distal end portion of the holding portion 46 is inclined with respect to the axial direction of the needle tube 21 so as to be closer to the inside in the radial direction than the base end portion on the cylindrical portion 45 side, that is, closer to the support portion 37. Engagement pieces 46a are provided on radially inner surfaces of the distal ends of the plurality of holding portions 46. The locking piece 46a protrudes substantially perpendicularly inward in the radial direction from the inner surface of the holding portion 46.

  In the state shown in FIG. 2, the plurality of holding portions 46 are locked by the contact pieces 29 of the protector 26. The holding portion 46 detachably holds the protector 26 at the first position against the urging force of the urging member 27.

  Further, the diameter of the space formed by the plurality of holding portions 46 when the plurality of holding portions 46 are in a natural state without elastic deformation (hereinafter, referred to as “holding diameter”) is outside the abutment piece 29 of the protector 26. It is set slightly larger than the diameter. The holding member 41 has a holding / maintaining portion 42 detachably attached thereto.

  The holding / maintaining portion 42 is formed in a substantially flat plate shape. A regulating hole 47 is formed in the holding / maintaining portion 42. The regulating hole 47 is formed at a substantially central portion of the holding / maintaining portion 42. The opening diameter of the restriction hole 47 is set to be larger than the outer diameter of the contact piece 29 of the protector 26.

  The cylindrical portion of the protector 26 and the support portion 37 are inserted into the restriction holes 47. Further, in the state shown in FIG. 2, the tips of the plurality of holding portions 46 are removably inserted into the restriction holes 47. The restriction hole 47 urges the plurality of holding portions 46 inward in the radial direction. Therefore, the plurality of holding portions 46 are elastically deformed so as to rotate around the base end on the cylindrical portion 45 side as a fulcrum. As a result, the holding diameter of the plurality of holding portions 46 is reduced by the restriction holes 47.

  Both ends of the holding / maintaining portion 42 with the regulating hole 47 interposed therebetween are inserted into a first opening 38 provided in the base portion 31 and a second opening 55 provided in a second member described later. The holding / maintaining portion 42 is supported by the base portion 31 and the second member so as to be movable in the axial direction of the needle tube 21. At this time, the surface of the holding / maintaining portion 42 where the restriction hole 47 is provided intersects the axial direction of the needle tube 21.

  The holding member 41 and the holding / maintaining portion 42 constitute a holding / releasing mechanism.

  Further, the first member 23 has a retaining member 43. The retaining member 43 is formed in a substantially disk shape. The retaining member 43 is fixed to the base 31 so as to close the opening on one side in the axial direction of the housing recess 36. A support hole 43a is opened at the center of the retaining member 43. The adjustment part 32, the support part 37, and the protector 26 are inserted through the support hole 43a. The retaining member 43 supports the protector 26 movably along the axial direction of the support portion 37.

  Before the needle tube 21 is punctured into the skin, the contact piece 29 of the protector 26 abuts on the other axial end surface of the retaining member 43. Thereby, the protector 26 urged by the urging member 27 can be prevented from falling off the first member 23.

[Second member]
Next, the second member 24 will be described. The second member 24 is formed in a tubular shape. One end of the second member 24 in the axial direction is an insertion portion 51 into which the base 31 of the first member 23 is inserted, and the other end is a fitting portion 52 into which the discharge portion of the syringe 3 is fitted. ing. The cylindrical hole 51 a of the insertion portion 51 is set to a size corresponding to the base portion 31 of the first member 23.

  A fixing piece 54 is provided on the outer peripheral surface of one end of the second member 24 in the insertion portion 51 in the axial direction. The fixing piece 54 is formed as a ring-shaped flange that protrudes outward in the radial direction continuously from the distal end of the insertion portion 51. The flat piece 35b of the connecting piece 35 provided on the first member 23 abuts on the fixing piece 54 and is fixed. Examples of a method of fixing the fixing piece 54 and the connecting piece 35 include an adhesive, ultrasonic welding, laser welding, and fixing screws.

  On the side wall of the insertion portion 51, second openings 55, 55 facing each other are formed. The second opening 55 is formed at a position facing the first opening 38 formed in the base 31 when the base 31 is inserted into the insertion portion 51. The second opening 55 penetrates the side wall of the insertion portion 51 to the cylindrical hole 51a. The holding portion 42 is inserted into the second opening 55 movably along the axial direction of the insertion portion 51.

  The outer diameter of the fitting portion 52 is set smaller than the outer diameter of the insertion portion 51. Further, the cylindrical hole 52 a of the fitting portion 52 is set to have a size corresponding to the discharge portion of the syringe 3, and has a continuously decreasing diameter toward the insertion portion 51. A male screw portion 52b for screwing with the lock mechanism 12 of the syringe 3 is provided on the outer peripheral surface of the fitting portion 52 (see FIG. 1). The elastic member 25 is disposed between the cylindrical hole 51a of the insertion portion 51 and the cylindrical hole 52a of the fitting portion 52.

[Elastic member]
Next, the elastic member 25 will be described. The elastic member 25 is made of an elastically deformable member. Examples of the material of the elastic member 25 include various rubber materials such as natural rubber, silicone rubber, and isobutylene rubber, various thermoplastic elastomers such as polyurethane and styrene, and elastic materials such as a mixture thereof. .

  The elastic member 25 is disposed inside the second member 24 and is interposed between the first member 23 and the syringe 3. Then, a gap generated between the outer peripheral surface on the proximal end side of the needle tube 21 protruding from the first member 23 and the second member 24 is filled. Then, when the discharge portion of the syringe 3 is fitted into the second member 24, the elastic member 25 is elastically deformed and adheres to the outer peripheral surface of the needle tube 21 in a liquid-tight manner. Thereby, the medicine filled in the syringe 3 can be prevented from penetrating between the needle tube 21 and the elastic member 25 and leaking to the first member 23 side.

1-2. Using the drug injection device will be described using the drug injection device 1 having the configuration described above with reference to FIGS.
FIG. 2 is a cross-sectional view showing a main part of the medicine injection device 1 during puncturing, and FIG. 3 is a cross-sectional view showing a main part of the medicine injection device 1 after puncturing.

  First, as shown in FIGS. 1 and 2, the syringe 3 is attached to the injection needle assembly 2 in advance. Specifically, the discharge part of the syringe 3 is inserted into the fitting part 52 of the second member 24, and the lock mechanism 12 is screwed into the male screw part 52b. Thus, the mounting of the injection needle assembly 2 on the syringe 3 is completed.

  At this time, the holding / maintaining portion 42 is disposed on the proximal side in the axial direction of the needle tube 21 in the first opening 38 and the second opening 55. A plurality of holding portions 46 are inserted into the restriction holes 47 of the holding and holding portion 42. The plurality of holding portions 46 are urged by the restriction holes 47, and the holding diameter is reduced.

  Further, the contact piece 29 of the protector 26 is locked by the locking pieces 46 a of the plurality of holding portions 46. The protector 26 is held by the holding member 41 at a first position where the needle tip 21a of the needle tube 21 is exposed. Further, the urging member 27 is elastically deformed and compressed between the other end in the axial direction of the protector 26 and the bottom surface 36 a of the housing recess 36.

  Next, the end face 33a of the stabilizer 33 is made to face the skin. Thus, the needle tip 21a of the needle tube 21 faces the skin to be punctured. Next, the medicine injection device 1 is moved substantially perpendicularly to the skin, the needle tip 21a is punctured into the skin, and the end face 33a of the stabilizer 33 is pressed against the skin. At this time, the needle protruding surface 32a comes into contact with the skin to deform the skin flat, and the needle tip 21a side of the needle tube 21 can be punctured into the skin by the protruding length L.

  Next, the end surface 33a of the stabilizer 33 is pressed until the contact surface 34a of the guide portion 34 contacts the skin. Here, the length of the guide portion Y (see FIG. 2) is set so that the needle tube 21 and the stabilizing portion 33 can puncture the skin with an appropriate pressing force. Therefore, the force of pressing the skin by the stabilizer 33 has a predetermined value.

  As a result, the appropriate pressing force of the stabilizer 33 can be recognized by the user, and the needle tip 21a and the blade surface of the needle tube 21 can be reliably positioned in the upper layer of the skin. As described above, the guide portion 34 serves as a mark for recognizing an appropriate pressing force of the stabilizer 33, so that the user can use the drug injection device 1 with ease.

  In addition, since the stabilizer 33 contacts the skin, the posture of the drug injection device 1 is stabilized, and the needle tube 21 can be punctured straight into the skin. In addition, blurring occurring in the needle tube 21 after puncturing can be prevented, and stable administration of the drug can be performed.

Further, in the case of a needle tube having a very short protruding length of, for example, about 0.5 mm, even if the needle tip is brought into contact with the skin, the needle tip may not pierce the skin. However, when the skin pressed against the stabilizer 33 is pressed down in the vertical direction, the skin inside the stabilizer 33 is pulled and the skin is in tension. Therefore, it is difficult for the skin to escape from the needle tip 21a of the needle tube 21. Therefore, by providing the stabilizer 33, it is possible to obtain an effect that the needle tip 21a is more easily pierced into the skin .

  After puncturing the needle tip 21a side of the needle tube 21 into the skin, the pusher member 4 (see FIG. 1) is pressed to move the gasket 13 to the discharge section side. As a result, the medicine filled in the liquid chamber 14 of the syringe 3 is pushed out from the discharge portion, and is injected into the upper layer of the skin from the needle tip 21a through the needle hole of the needle tube 21. At this time, since no space is formed between the distal end of the discharge portion and the proximal end of the needle tube 21, the remaining amount of the medicine can be reduced.

  Further, the pressing member 20 moves together with the plunger body 16 toward the needle tip 21a of the needle tube 21. Then, as shown in FIG. 3, the holding / maintaining portion 42 is pressed by the pressing member 20 and moves toward the needle tip 21 a side of the needle tube 21. Therefore, the plurality of holding portions 46 come out of the restriction holes 47 of the holding and holding portion 42. When the plurality of holding portions 46 escape from the restriction holes 47, the plurality of holding portions 46 are restored to their original shapes (natural states) by their own elasticity, and the holding diameter is expanded. Thereby, the holding of the protector 26 by the holding member 41 is released, and the pressing on the urging member 27 is also released.

  That is, the holding diameter of the plurality of holding portions 46 is configured to be deformable into a holding state in which the contact piece 29 of the protector 26 is held and a passing-off state in which the contact piece 29 of the protector 26 can pass.

  Next, the medicine injection device 1 is separated from the skin, and the end surface 33a of the stabilizer 33, the needle projecting surface 32a, and the distal end surface 26a of the protector 26 are separated from the skin. The protector 26 is urged toward the needle tip 21a of the needle tube 21 by the restoring force (urging force) of the urging member 27. Therefore, the protector 26 is supported by the outer peripheral surface of the support portion 37 and the support hole 43a of the retaining member 43, and moves from the other side in the axial direction of the support portion 37, that is, from the first position to the second position. Move toward.

  Here, the size of the holding diameter of the plurality of holding portions 46 in the natural state is set to be larger than the outer diameter of the contact piece 29 of the protector 26. Therefore, when the contact piece 29 of the protector 26 passes through the locking pieces 46a of the plurality of holding portions 46, the protector 26 can be moved smoothly without the contact pieces 29 being hooked on the locking pieces 46a. .

  The contact piece 29 abuts on the retaining member 43, thereby restricting the movement of the protector 26 to one side in the axial direction. Thereby, it is possible to prevent the protector 26 from falling off from the support portion 37 of the first member 23.

  The protector 26 covers the periphery of the needle tip 21 a of the needle tube 21, and the needle tube 21 is housed in the protector 26. That is, the protector 26 moves from the first position to the second position. Thereby, the protector 26 can be automatically moved in accordance with the puncturing operation, and the circumference of the needle tip 21a of the needle tube 21 can be easily covered. As a result, the needle tip 21a of the used needle tube 21 can be kept in a safe state, and it is possible to prevent the needle tip 21a of the used needle tube 21 from being punctured against the intention of the user.

  Further, since the needle tip 21a of the used needle tube 21 is covered with the protector 26, it is possible to prevent the blood attached to the needle tip 21a from scattering and prevent infection by blood.

  When the protector 26 moves to the second position, the support portion 37 may be provided with a return restricting portion that locks with the protector 26 and restricts the movement of the protector 26 to the first position. Thus, it is possible to prevent the needle tip 21a of the needle tube 21 after the puncture from protruding from the distal end surface 26a of the protector 26 again.

  Further, the holding diameter of the plurality of holding portions 46 may be set to be slightly smaller than the outer diameter of the contact piece 29. In this case, when the contact piece 29 passes through the plurality of holding parts 46, the inclined surface 29 a provided on the contact piece 29 comes into contact with the locking piece 46 a of the plurality of holding parts 46.

  The inclined surface 29a is formed in a tapered shape whose diameter continuously decreases from one side to the other side in the axial direction. Therefore, the plurality of holding portions 46 are pressed outward in the radial direction, and the holding diameter of the plurality of holding portions 46 is increased. Thereby, the contact piece 29 can be passed between the plurality of holding portions 46 without being caught by the plurality of holding portions 46. Further, when passing through the contact piece 29, the pressing force on the plurality of holding portions 46 is released, and the plurality of holding portions 46 return to the original shape (natural state) by its own elasticity.

  Further, a corner portion of the contact piece 29 on the opposite side to the inclined surface 29a is set at a substantially right angle. Therefore, when the protector 26 is pressed from one side of the support portion 37 in the axial direction to the other side, the contact piece 29 comes into contact with the plurality of holding portions 46 of the holding member 41, and the holding diameter is increased. Nothing. Therefore, even with such a configuration, the movement of the protector 26 after puncturing from one side in the axial direction to the other side, that is, returning from the second position to the first position can be restricted. Thereby, it is possible to prevent the needle tip 21a of the needle tube 21 after the puncture from protruding from the distal end surface 26a of the protector 26 again.

2. Second Embodiment Next, a drug injection device according to a second embodiment will be described with reference to FIGS.
FIG. 4 is a sectional view showing a state before puncturing.

  The difference between the drug injection device according to the second embodiment and the drug injection device 1 according to the first embodiment is the configuration of the holding unit and the holding release unit in the injection needle assembly. Therefore, here, the holding portion and the holding release portion will be mainly described, and portions common to the injection needle assembly 2 according to the first embodiment will be denoted by the same reference numerals, and redundant description will be omitted. I do.

  As shown in FIG. 4, the injection needle assembly 60 includes a hollow needle tube 21 and a needle hub 62 that holds the needle tube 21. The needle hub 62 includes a first member 63, a second member 64 into which the discharge portion of the syringe 3 is fitted, an elastic member 25, a protector 66, a biasing member 67, and a holding and releasing mechanism 79. I have.

  The first member 63 includes a base portion 71, an adjusting portion 72, a stabilizing portion 73, a guide portion 74, and a support portion 77. The base 71 is formed in a substantially columnar shape. The base 71 has an accommodation recess 76 formed therein. One end of the base portion 71 in the axial direction is entirely open. The accommodation recess 76 is formed to be substantially cylindrically recessed from one end in the axial direction of the base portion 71 to the other end. A support portion 77 is formed in the accommodation recess 76.

The base 71 has two first openings 78 facing each other. The two first openings 78 penetrate the side wall of the base 71 to the housing recess 76. A holding member 81 of a holding and releasing mechanism 79 described later is slidably inserted into the two first openings 78 along a direction orthogonal to the axial direction of the base 71 .

  Like the protector 26 according to the first embodiment, the protector 66 is formed in a cylindrical shape, and has a contact piece 69 at the other end in the axial direction. An urging member 67 is arranged between the other end of the protector 66 in the axial direction and the bottom surface 76 a of the housing recess 76.

  The first member 63 has a retaining member 86. The retaining member 86 is formed in a substantially disk shape, and has a support hole 86a opened in the center thereof. The adjustment part 72, the support part 77, and the protector 66 are inserted through the support hole 86a. The retaining member 86 supports the protector 66 so as to be movable in the axial direction of the support portion 77.

  The second member 64 has an insertion portion 91 into which the base portion 71 is inserted, and a fitting portion 92 into which the discharge portion of the syringe 3 is fitted. In the side wall of the insertion portion 91, two second openings 95, 95 facing each other are formed. The second opening 95 is formed at a position facing the first opening 78 formed in the base 71 when the base 71 is inserted into the insertion portion 91. The second opening 95 penetrates the side wall of the insertion section 91 to the cylindrical hole 91a. A holding member 81 of a holding and releasing mechanism 79 described later is slidably inserted into the second opening 95 along a direction orthogonal to the axial direction of the insertion portion 91.

  Next, the holding and releasing mechanism 79 showing the holding unit and the holding releasing unit will be described. The holding and releasing mechanism 79 has a holding member 81, an urging portion 87, and an operation plate 88. The holding member 81 is formed in a substantially flat plate shape. The holding member 81 is inserted into the first opening 78 of the base 71 and the second opening 95 of the insertion portion 91. The holding member 81 is slidably supported by the first opening 78 and the second opening 95 along a direction orthogonal to the axial direction of the needle tube 21. An opening 82 into which the protector 66 can be inserted is provided at a substantially central portion of the holding member 81.

FIG. 5 is a plan view showing the holding member 81.
As shown in FIG. 5, the opening 82 has a small-diameter opening 82a and a large-diameter opening 82b. The large diameter opening 82b is formed continuously from the outer edge of the small diameter opening 82a. The large-diameter opening 82b is formed on one side in the longitudinal direction of the holding member 81 in the opening 82, and the small-diameter opening 82a is formed on the other side in the longitudinal direction of the holding member 81 in the opening 82.

  The opening diameter of the small-diameter opening portion 82 a is set to be larger than the diameter of the cylindrical portion of the protector 66 and smaller than the outer diameter of the contact piece 69 of the protector 66. The opening diameter of the large-diameter opening 82b is set to be larger than the outer diameter of the contact piece 69. The large-diameter opening 82b allows the contact piece 69 to pass through.

  Note that the holding member 81 is not limited to the above-described one, and the opening hole 82 is only the large-diameter opening portion 82b in FIG. By not being arranged coaxially, the contact piece 69 may be in contact with a part of the edge of the opening 82.

In the state before puncturing shown in FIG. 4, the cylindrical portion of the protector 66 and the support portion 77 are inserted into the small-diameter opening 82a. The contact piece 69 of the protector 66 contacts the outer edge of the small-diameter opening 82a. The holding member 81 holds the protector 66 at the first position.

  As shown in FIG. 4, one end of the holding member 81 is provided with a pressing portion 83 that is substantially vertically continuous toward the other side in the axial direction of the needle tube 21. The pressing portion 83 is formed on the large-diameter opening portion 82b side of the opening hole 82. A tapered surface 83a is formed at a corner of the pressing portion 83 on the other side in the axial direction of the needle tube 21. The tapered surface 83a is inclined in a direction away from the center of the holding member 81 as going from the other side in the axial direction of the needle tube 21 to one side.

  An urging portion 87 is arranged between the pressing portion 83 and the insertion portion 91 of the second member 64. When the holding member 81 is inserted into the first opening 78 and the second opening 95, the pressing part 83 faces the outer peripheral surface of the insertion part 91 of the second member 64. An urging portion 87 is disposed between a surface of the pressing portion 83 facing the insertion portion 91 and an outer peripheral surface of the insertion portion 91.

  The urging portion 87 is formed of, for example, a compression coil spring. The urging portion 87 urges the holding member 81 in a direction in which the pressing portion 83 is separated from the insertion portion 91 along a direction orthogonal to the axial direction of the needle tube 21.

  Although the example in which the compression coil spring is applied as the urging portion 87 has been described, the invention is not limited to this. The urging portion may be any elastic member that elastically deforms when a predetermined pressing force is applied. For example, various other spring members such as a leaf spring, sponge, gel, and rubber members can be applied.

  The operation plate 88 is formed in a substantially flat plate shape. The operation plate 88 is arranged on the other axial side of the needle tube 21 than the holding member 81. An operation hole 89 is formed in the operation plate 88. The insertion portion 91 is inserted into the operation hole 89. The operation plate 88 is supported by the insertion portion 91 so as to be movable in the axial direction of the needle tube 21, and faces the pressing member 20 of the pusher member 4.

  An operation-side tapered surface 89a is formed at an end of the operation hole 89 on the pressing portion 83 side of the holding member 81. The operation side tapered surface 89a is inclined in a direction away from the center of the operation hole 89 as going from the other side in the axial direction of the needle tube 21 to one side. Then, the operation side tapered surface 89a comes into contact with the tapered surface 83a of the pressing portion 83.

Next, the operation of the protector 66 of the injection needle assembly 60 according to the second embodiment having the above-described configuration will be described with reference to FIGS. FIG. 6 is a cross-sectional view showing the state of the injection needle assembly 60 after puncturing.

As shown in FIG. 5, before the puncture, the tubular portion of the protector 66 penetrates the small-diameter opening 82 a of the holding member 81, and the contact piece 69 contacts the outer edge of the small-diameter opening 82 a. Therefore, the protector 66 is held by the holding member 81 at the first position where the needle tip 21a of the needle tube 21 projects from the distal end surface 66a.

  Next, when the pusher member 4 is operated to move the pressing member 20 together with the plunger body 16 (see FIG. 1) toward one side in the axial direction, the pressing member 20 presses the operation plate 88. When pressed by the pressing member 20, the operation plate 88 slides on the outer peripheral surface of the insertion portion 91 and moves toward one axial side of the needle tube 21.

  When the operation plate 88 moves toward one side in the axial direction of the needle tube 21, the pressing portion 83 of the holding member 81 is inserted into the operation hole 89 of the operation plate 88. Then, the operation side tapered surface 89a of the operation hole 89 and the tapered surface 83a of the pressing portion 83 abut.

  Further, when the operation plate 88 moves toward one side in the axial direction of the needle tube 21, the pressing portion 83 is pressed by the operation side tapered surface 89 a of the operation hole 89 in a direction approaching the outer peripheral surface of the insertion portion 91. . Then, as shown in FIG. 6, the holding member 81 moves from one side in the direction orthogonal to the axial direction of the needle tube 21 toward the other side against the urging force of the urging portion 87. That is, the operation plate 88 and the pressing portion 83 constitute a release operation unit.

  When the holding member 81 moves from one side in the direction orthogonal to the axial direction of the needle tube 21 to the other side, the contact piece 69 of the protector 66 faces the large-diameter opening 82 b of the opening 82. The opening diameter of the large-diameter opening 82 b is set to be larger than the outer diameter of the contact piece 69. Thereby, the holding of the protector 66 by the holding member 81 is released. That is, the holding member 81 is changed from the holding state in which the contact piece 69 is held to the passing state in which the contact piece 69 can pass.

  The protector 66 is urged by the restoring force (urging force) of the urging member 67 from the needle tip 21a side of the needle tube 21, that is, from the first position to the second position. As a result, the protector 66 covers the periphery of the needle tip 21a of the needle tube 21, and the needle tube 21 is accommodated in the protector 66.

  Other configurations are the same as those of the injection needle assembly 2 according to the first embodiment, and therefore, description thereof will be omitted. With the injection needle assembly 60 having such a configuration, the same operation and effect as those of the injection needle assembly 2 according to the above-described first embodiment can be obtained.

  The embodiment of the drug injection device and the injection needle assembly of the present invention has been described above, including the operation and effect thereof. However, the medicine injection device and the injection needle assembly of the present invention are not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention described in the claims. .

  In the above-described embodiment, an example in which a luer lock portion is provided as the lock mechanism 12 has been described. However, the present invention is not limited to this. A male screw portion is provided in the discharge portion, and the second member of the injection needle assembly 2 A female screw portion may be provided in the 24 cylindrical hole and screwed together.

  In the above-described embodiment, an example has been described in which the pressing member is provided with the pressing member to release the holding of the protector during the puncturing operation. However, the present invention is not limited to this. For example, without providing the pressing member, the user may operate the holding / maintaining portion 42 by hand or press the pressing portion 83 of the holding member 81.

  Furthermore, elasticity is given to the contact piece of the protector, and the contact piece is detachably engaged with the first opening of the base portion and the second opening of the insertion portion, and the protector is held by the base portion and the insertion portion. May be configured. Then, the holding of the protector may be released by releasing the engagement between the contact piece and the first opening and the second opening.

Furthermore, in the above-described embodiment, the example in which the urging member is arranged between the bottom surface of the housing recess and the rear end in the axial direction of the protector has been described, but the place where the urging member is arranged is not limited to this. It is not something to be done. For example, you may comprise so that an urging member may be arrange | positioned at the needle tip 21a side of the needle tube 21 rather than the holding maintenance part 42 and the holding member 81. Accordingly, it is possible to prevent the biasing member from interfering with the holding unit or the holding release unit, and to smoothly move the protector.

  Further, two holding members 81 of the second embodiment are prepared, and the two holding members 81 are overlapped so that the center point of the opening 82 is not coaxial. In this state, the contact piece 69 is in contact with a part of the edge of both opening holes 82. Then, the two holding members 81 may be moved in opposite directions to each other, and the opening formed by the two opening holes may be enlarged, so that the contact of the contact piece 69 may be released.

DESCRIPTION OF SYMBOLS 1 ... Drug injection device, 2, 60 ... Injection needle assembly, 3 ... Syringe, 4 ... Presser member, 16 ... Plunger body, 20 ... Pressing member, 21 ... Needle tube, 21a ... Needle tip, 22, 62 ... Needle hub , 23, 63: first member, 24, 64: second member, 26, 66: protector, 26a, 66a: distal end surface, 27, 67: urging member, 29, 69: contact piece, 29a: inclined surface 31, 31, ... base part, 32, 72 ... adjustment part, 32a, 72a ... needle protruding surface, 33, 73 ... stable part, 33a ... end face, 34, 74 ... guide part, 34a ... contact surface, 36, 76 ... Housing recesses, 36a, 76a: bottom surface, 37: support portion, 38 , 78 : first opening, 40: space, 41, 81: holding member, 42: holding and maintaining portion, 43, 86: retaining member, 43a, 86a ... support hole, 45 ... cylindrical portion 46: holding portion, 46a: locking piece, 47: regulating hole, 51, 91: insertion portion, 55, 95: second opening, 79: holding and releasing mechanism, 82: opening hole, 82a: small diameter opening, 82b: large-diameter opening, 83: pressing portion, 83a: tapered surface, 87: urging portion, 88: operation plate, 89: operation hole, 89a: operation-side tapered surface

Claims (9)

A needle tube having a needle tip that can puncture a living body,
A needle hub for holding the needle tube;
A protector movable to a first position exposing the needle tip of the needle tube, and a second position covering the needle tip of the needle tube;
An urging member for urging the protector from the first position to the second position along the axial direction of the needle tube;
A contact piece provided on the protector,
When the protector moves to the second position, a retaining member that comes into contact with the contact piece;
A holding and releasing mechanism for detachably holding the protector at the first position ;
Equipped with a,
The holding and releasing mechanism includes:
A holding member having a holding portion detachably engaged with the contact piece;
A holding member in which the holding portion is inserted, and a regulating hole for reducing a diameter of an opening formed in the holding portion is provided,
The injection needle assembly wherein the holding member is disengaged from the contact piece when the holding member comes out of the restriction hole . The holding and releasing mechanism includes:
The injection needle assembly according to claim 1, wherein the injection needle assembly is configured to be deformable or changeable to a holding state capable of holding the contact piece and a passing state capable of passing the contact piece. The holding member has a plurality of holding portions, and when coming out of the regulating hole, the diameter of the opening formed by the plurality of holding portions is increased, so that the engagement with the contact piece is prevented. The injection needle assembly according to claim 1 or 2 , which is released. A needle tube having a needle tip that can puncture a living body,
A needle hub for holding the needle tube;
A protector movable to a first position exposing the needle tip of the needle tube, and a second position covering the needle tip of the needle tube;
An urging member for urging the protector from the first position to the second position along the axial direction of the needle tube;
A contact piece provided on the protector,
When the protector moves to the second position, a retaining member that comes into contact with the contact piece;
A holding and releasing mechanism for detachably holding the protector at the first position;
With
The holding and releasing mechanism includes:
Having a holding member provided with an opening hole into which the protector can be inserted,
Said opening hole, Ri Do from that the contact piece in a part of its edge abuts,
The opening hole,
A small-diameter opening with which the contact piece abuts,
A large-diameter opening provided continuously with the small-diameter opening and through which the contact piece can pass . The holding and releasing mechanism includes:
5. The injection needle assembly according to claim 4 , further comprising a release operation unit configured to operate the holding member to change a position where the contact piece faces the opening hole. The holding and releasing mechanism includes:
5. The injection needle assembly according to claim 4 , further comprising: a release operation unit configured to operate the holding member to change a position of the contact hole facing the contact hole in the opening from the small-diameter opening to the large-diameter opening. An injection needle assembly including a needle tube having a needle tip that can puncture a living body,
A syringe removably attached to the injection needle assembly,
The injection needle assembly includes:
A needle hub for holding the needle tube;
A protector movable to a first position exposing the needle tip of the needle tube, and a second position covering the needle tip of the needle tube;
An urging member for urging the protector from the first position to the second position along the axial direction of the needle tube;
A contact piece provided on the protector,
When the protector moves to the second position, a retaining member that comes into contact with the contact piece,
A holding and releasing mechanism for detachably holding the protector at the first position ;
Equipped with a,
The holding and releasing mechanism includes:
A holding member having a holding portion detachably engaged with the contact piece;
A holding member in which the holding portion is inserted, and a regulating hole for reducing a diameter of an opening formed in the holding portion is provided,
The medicine injection device , wherein the holding member is disengaged from the contact piece when the holding member comes out of the regulation hole . An injection needle assembly including a needle tube having a needle tip that can puncture a living body,
A syringe removably attached to the injection needle assembly,
The injection needle assembly includes:
A needle hub for holding the needle tube;
A protector movable to a first position exposing the needle tip of the needle tube, and a second position covering the needle tip of the needle tube;
An urging member for urging the protector from the first position to the second position along the axial direction of the needle tube;
A contact piece provided on the protector,
When the protector moves to the second position, a retaining member that comes into contact with the contact piece;
A holding and releasing mechanism for detachably holding the protector at the first position;
With
The holding and releasing mechanism includes:
Having a holding member provided with an opening hole into which the protector can be inserted,
The opening hole is formed by the contact piece abutting a part of the edge thereof,
The opening hole,
A small-diameter opening with which the contact piece abuts,
A large-diameter opening which is provided continuously with the small-diameter opening and through which the contact piece can pass.
Drug injection device. A plunger body for sliding a gasket slidably disposed on the syringe,
The medicine injection device according to claim 7 , further comprising: a pressing member that moves together with the plunger body and operates to release the holding of the protector by the holding and releasing mechanism.

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