HK1162365A

HK1162365A - Injection needle assembly and drug injection device

Info

Publication number: HK1162365A
Application number: HK12102777.1A
Authority: HK
Inventors: 岩濑阳一郎; 小岩井一伦; 田中哲夫; 大森初夏
Original assignee: 泰尔茂株式会社
Priority date: 2009-01-30
Filing date: 2010-01-29
Publication date: 2012-08-31

Description

Injection needle assembly and drug injection device

Technical Field

The present invention relates to an injection needle assembly and a drug injection device for injecting a drug into an upper layer of skin by inserting a needle tip into a skin surface.

Background

Recently, cases of human infection with avian influenza have been reported, and there is a fear that widespread (pandemic) of avian influenza from person to person may cause significant damage. Thus, pre-pandemic vaccine (pre-pandemic vaccine) that is likely to be effective against avian influenza is reserved globally. In addition, in order to inject a large number of people with a pre-pandemic vaccine, studies to expand the production of the vaccine are being conducted.

The skin consists 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 3.5mm continuous with the epidermis. Since influenza vaccines are usually injected subcutaneously or intramuscularly, the influenza vaccines are injected into the lower layer part of the skin or a part deeper than the lower layer part.

On the other hand, it has been reported that: by injecting an influenza vaccine into an upper layer portion of the skin where many immunocompetent cells (immunocompetent cells) exist as a target site, even if the dose is reduced, the same immune-gaining ability as that of subcutaneous injection or intramuscular injection can be obtained (non-patent document 1). Therefore, by injecting the avian influenza vaccine into the upper layer of the skin, the dose can be reduced, and the avian influenza vaccine can be injected into a larger number of people. Incidentally, the upper layer part of the skin means the epidermis and dermis of the skin.

As a method of injecting a drug into the upper layer of the skin, a method using a single needle, multiple needles, patch (patch), gas, or the like has been reported. In view of stability and reliability of injection and production cost, a method using a single needle is the most suitable method of injecting the agent to the upper layer portion of the skin. As a method of injecting a vaccine into the upper layer of the skin using a single needle, a Mantoux (Mantoux) method has been known for a long time. In the Mantoux method, a needle having a short beveled tip, typically 26G-27G gauge, is inserted into the skin about 2 mm-5 mm from a direction inclined at about 10-15 relative to the skin to inject about 100 μ L of the medicament.

However, the Mantoux method is difficult to manipulate and is influenced by the skill of the physician performing the injection. In particular, it is difficult to inject influenza vaccine to children using the Mantoux method because children may move while injecting. Therefore, it is desirable to develop a device that can inject a vaccine into the upper layer of the skin in a simple and convenient manner.

Patent document 1 discloses an injection device for injecting a medicament into an upper layer portion of skin. In this injection device, a limiter having a skin contact surface is connected to a needle hub (needle hub). The limiter of the injection device described in patent document 1 is formed in a cylindrical shape covering the outer periphery of the needle tube with a clearance from the needle tube. The medicament is injected into the skin by limiting the length of projection (projection length) of the needle tube from the skin-contacting surface of the limiter to the range of 0.5mm to 3.0 mm.

In addition, patent document 2 discloses a piercing adjustment tool for an injection needle adapted to prevent the injection needle from piercing the skin to a depth greater than a target depth. The puncture adjustment tool for an injection needle disclosed in patent document 2 includes a member formed in a cylindrical shape so as to cover the periphery of the injection needle and to have a gap with the injection needle. The tubular puncture adjustment tool for an injection needle includes a member in which a needlepoint of the injection needle is formed at a position not protruding from an end portion. When the needle is pressed hard against the skin with the piercing adjustment tool, the needle protrudes from the skin with the piercing adjustment tool, thereby inserting the needle into the skin. In addition, the puncture adjustment tool for an injection needle disclosed in patent document 2 includes a device that closely contacts the outer periphery of the needle tube.

Patent document 1: japanese patent laid-open publication No. 2001-137343

Patent document 2: japanese patent laid-open No. 2000-037456

Non-patent document 1: R.T.Kenney et al New England Journal of medicine, 351, 2295-

Disclosure of Invention

Problems to be solved by the invention

However, since the injection device disclosed in patent document 1 includes the limiter having the skin-contacting surface around the needle tube, a clearance of a predetermined size is provided between the limiter and the outer periphery of the needle tube. Thus, if the limiter is pressed against the skin, the skin may bulge in the gap between the limiter and the outer circumference of the needle cannula.

The thickness of the upper layer (epidermis and dermis) of the skin varies depending on the injection site, sex, race, and age, but the depth from the skin surface ranges from about 0.5mm to 3.0 mm. Further, patent document 1 discloses that the most preferable projection length of the injection needle (the length of projection from the skin contact surface of the limiter) is 1.5 mm. On the other hand, it has been reported that the thickness of the upper layer part of the skin of the deltoid muscle, which is the normal site of vaccine injection, is about 1.5mm in a person with thin skin. As a result, if skin protrudes in the gap between the limiter and the outer periphery of the needle tube, there is a fear that the tip of the needle tube may reach the subcutaneous tissue.

The epidermis and dermis are composed of dense fibrous connective tissue and are harder than subcutaneous tissue, and therefore, if the tip of the needle tube is made to reach the subcutaneous tissue, the injected agent such as vaccine will move from the dermal tissue to the subcutaneous tissue, and thus the desired effect cannot be obtained.

On the other hand, in the needle puncturing adjustment tool disclosed in patent document 2, the height of the skin protrusion in the needle puncturing adjustment tool is equal to the insertion depth of the needle. Since the skin protuberance formed in the needle puncture adjustment tool varies depending on the applied pressure when the needle puncture adjustment tool is pressed against the skin, it is difficult to constantly position the piercing tip and the blade surface of the needle inserted into the skin at the upper layer of the skin.

In addition, in the injection devices disclosed in patent documents 1 and 2, since the stopper disposed around the needle tube and the puncturing adjustment tool for the injection needle closely contacting the outer periphery of the needle tube are provided, it is difficult to see the needlepoint of the needle tube. Therefore, with the techniques disclosed in patent document 1 and patent document 2, it is difficult for the user to recognize how much pressure is applied to cause the needle tube to penetrate the living body. In addition, since an appropriate pressure for pressing the injection device against the living body cannot be recognized, the user has an uneasy feeling that the needle tip and the blade face of the injection needle are not reliably positioned on the upper layer portion of the skin.

The present invention has been made in view of the above problems, and an object of the present invention is to reliably position a needlepoint and a blade face of an injection needle inserted into skin at a predetermined position of a living body, for example, at an upper layer portion of the skin.

Means for solving the problems

In order to solve the above-mentioned problems and achieve the object of the present invention, an injection needle assembly according to one aspect of the present invention includes: a needle tube having a needle tip capable of piercing a living body; a needle hub for holding the needle cannula; a stabilizer and a guide. The stabilizer is formed in a cylindrical shape surrounding an outer periphery of the needle tube, and has an end surface that comes into contact with a skin of a living body when the living body is punctured with the needle tube. A guide portion is provided to the stabilizer, the guide portion guiding a pressurizing parameter applied from the needle tube and the stabilizer to the living body by contact with the skin when the living body is punctured with the needle tube.

A medicament injection device according to another aspect of the present invention comprises: a needle tube having a needle tip capable of piercing a living body; a needle hub for holding the needle cannula; a syringe connected to the needle hub; a stabilizer and a guide. The stabilizer is formed in a cylindrical shape surrounding an outer periphery of the needle tube, and has an end surface that comes into contact with a skin of a living body when the living body is punctured with the needle tube. A guide portion is provided to the stabilizer, the guide portion guiding a pressurizing parameter applied from the needle tube and the stabilizer to the living body by contact with the skin when the living body is punctured with the needle tube.

Incidentally, the "guide pressurizing parameter" means that, when a living body is pierced with a needle tube, a pressurizing parameter for pressing the needle tube and the stabilizer against the living body is guided or recognized so that the pressurizing parameter becomes a predetermined value.

In addition, the stabilizer of the injection needle assembly of the present invention is a skin deformer adapted to form a skin protrusion in the tube hole of the stabilizer by pressing the end face of the stabilizer against the skin. The pressing parameter is a pressing distance at which the skin deformer is pressed into the skin, and the guide unit is a distance identifier adapted to identify the pressing distance.

In the injection needle assembly, the penetration distance of the skin deformer into the skin can be recognized by the distance recognizer. Therefore, when the end surface of the skin deformer is pressed against the skin, the skin press-in distance becomes constant, whereby the height of the skin protrusions formed in the tube holes of the skin deformer can be made constant. The needle tube penetrates the skin protrusion.

In addition, the injection needle assembly further includes an adjustment portion disposed around the needle tube, the adjustment portion having a needle protruding surface from which a needlepoint of the needle tube protrudes. The specification of the needle tube is 26G-33G, and the pressurization parameter is pressure.

ADVANTAGEOUS EFFECTS OF INVENTION

With the injection needle assembly and the drug injection device according to the present invention, since the guide portion for guiding the pressurization parameter when the living body is pierced is provided, the needlepoint and the blade face of the needle tube can be reliably positioned on the skin layer portion.

According to the injection needle assembly and the drug injection device of the present invention, the height of the skin protrusion formed by the skin deformer can be made constant, and the needle tip and the blade surface of the needle tube can be reliably positioned on the skin layer portion.

In addition, with the injection needle assembly and the medicine injection device according to the present invention, the pressure applied to the living body from the needle tube and the stabilizer can be guided to the user through the guide portion, and therefore, the user can surely pierce the needle tube into the skin with an appropriate predetermined pressure. In addition, since an appropriate pressure applied to the living body from the needle tube and the stabilizer can be recognized, the user can use the medicine injection device without feeling of anxiety, and the needle tip and the blade face of the needle tube can be reliably positioned on the skin layer portion.

Drawings

Fig. 1 is a view showing the configuration of an injection needle assembly according to a first embodiment of the present invention.

Fig. 2 is a perspective view showing an injection needle assembly according to a first embodiment of the present invention.

Fig. 3 is a view for explaining a state in which a needle tube of the medicine injection device according to the first embodiment of the present invention is penetrated into the skin.

Fig. 4A and 4B are diagrams illustrating a measuring device for measuring the height of a skin protrusion and a distance formed in a tube corresponding to an identifier height obtained by a skin deformer of an injection needle assembly according to a first embodiment of the present invention.

Fig. 5 is a graph showing the height of the skin-protrusion (skin-protrusion length) and the distance corresponding to the height of the identifier (moving distance of the outer tube) measured using the measuring apparatus shown in fig. 4A and 4B, which is obtained by changing the diameter of the tube hole of the skin deformer.

Fig. 6 is a graph showing the height of a skin protrusion measured using the measuring apparatus shown in fig. 4A and 4B, in which the measured value is obtained by changing the diameter of the tube hole of the skin deformer and the distance corresponding to the height of the identifier (the moving distance of the outer tube).

Fig. 7 is a graph showing the height of the skin protrusion measured using the measuring device shown in fig. 4A and 4B and the distance (moving distance of the outer tube) corresponding to the height of the identifier, the measured value being obtained by changing the length of the identifier.

Fig. 8 is a graph showing the height of the skin protrusion measured using the measuring device shown in fig. 4A and 4B, in which the measured value is obtained by changing the length of the identifier and the moving distance of the outer tube corresponding to the height of the identifier.

Fig. 9 is a diagram showing the relationship between the height of the identifier and the height of the skin protrusion.

Fig. 10 is a view showing the configuration of an injection needle assembly according to a second embodiment of the present invention.

Fig. 11 is a perspective view showing an injection needle assembly according to a third embodiment of the present invention.

Fig. 12 is a view showing the configuration of an injection needle assembly according to a fourth embodiment of the present invention.

Fig. 13 is a perspective view showing an injection needle assembly according to a fourth embodiment of the present invention.

Fig. 14 is a view for explaining a state in which a needle tube of a medicine injection device according to a fourth embodiment of the present invention is penetrated into the skin.

Fig. 15A and 15B are views showing a measuring device for measuring the height of a guide portion of a medicament injection device according to a fourth embodiment of the present invention, in which fig. 15A is a view showing a state in which the measuring device is mounted on the skin, and fig. 15B is a view showing a state in which a pressing member of the measuring device is pressed.

Fig. 16 is a graph showing the measurement value of the height of the guide portion obtained by changing the inner diameter of the contact portion.

Fig. 17 is a diagram showing measurement values of the guide height obtained by changing the guide length.

Fig. 18 is a view showing the configuration of an injection needle assembly according to a fifth embodiment of the present invention.

Description of the reference numerals

1. 11, 21, 31, 41 needle assembly

2 needle tube

2a edge face

3 needle hub

4. 14 stabilizer

5. 15 fixed part

5a, 15a pipe hole

6. 16 contact part

6a, 16a pipe hole

6b, 16b end face

7. 17, 27 guide part (distance recognizer)

7a, 17a contact surface

9 Syringe

34 regulating part

34a needle hub opposing face

34b needle protruding surface

Length of B slope

d inner diameter

Length of protrusion of L-shaped needle

Length of P insertion

S distance from the periphery of the needle protruding surface to the outer peripheral surface of the needle tube

T distance from inner wall of stabilizer to outer peripheral surface of adjusting part

Length of guide part x (length of recognizer)

y guide height (recognizer height)

z skin protrusion length

Detailed Description

Hereinafter, embodiments of an injection needle assembly and a medicament injection device according to the present invention will be described with reference to fig. 1 to 18. It should be noted that in the respective drawings, the same constituent elements are denoted by the same reference numerals. In addition, the present invention is not limited to the following embodiments.

1. First embodiment

[ construction examples of an injection needle Assembly and a drug injection device ]

Hereinafter, an injection needle assembly and a medicament injection device according to a first embodiment of the present invention will be described with reference to fig. 1 to 3.

Fig. 1 is a view showing the configuration of an injection needle assembly according to a first embodiment of the present invention. Fig. 2 is a perspective view showing an injection needle assembly according to a first embodiment of the present invention. Fig. 3 is a view for explaining a state where the needle tube of the injection needle assembly of the medicine injection device has penetrated into the skin.

The injection needle assembly 1 includes a hollow needle tube 2 having a needle hole 2b, a needle hub 3 holding the needle tube 2, and a stabilizer (which is a skin deformer) 4 fixed to the needle hub 3. The medicament injection apparatus of the present invention is constituted by connecting a syringe 9 (see fig. 3) to the hub 3 of the injection needle assembly 1.

As the needle tube 2, a needle tube having a gauge of 26G to 33G (outer diameter: 0.2mm to 0.45mm) according to ISO medical needle tube standard (ISO 9626: 1991/Amd.1: 2001(E)), preferably a needle tube having a gauge of 30G to 33G, is used. A blade face 2a is formed at the tip end (tip end) of the needle tube 2 so that the needle tip is at an acute angle. The length of the blade face 2a in the extending direction of the needle tube 2 (hereinafter referred to as "bevel length" B ") may be 1.4mm or less, but about 0.5mm or more, where 1.4mm is the thinnest thickness of the upper layer portion of adult skin (to be described later), and 0.5mm is the bevel length when a short bevel is formed in a 33G needle tube. In other words, the slope length B is preferably set in the range of 0.5mm to 1.4 mm.

The slope length B is more preferably 0.9mm or less, where 0.9mm is the thinnest thickness of the upper layer of the skin of the child. That is, the slope length B is more preferably set in the range of 0.5mm to 0.9 mm. Incidentally, the short bevel refers to a blade face forming an angle of 18 ° to 25 ° with respect to the longitudinal direction of the needle, which is commonly used in injection needles.

The material of the needle cannula 2 may be, for example, stainless steel, aluminum alloy, titanium alloy, and other metals. In addition, the needle tube 2 may be a straight needle or a tapered needle at least a part of which is tapered, or the like. The tapered needle may have the following configuration: the outer diameter of the base end portion fixed to the needle hub 3 is larger than the outer diameter of the tip end portion including the needle tip, and the middle portion is tapered.

The needle hole 2b of the needle tube 2 communicates with the needle hub 3. The hub 3 includes a hub body 3a holding the needle tube 2 and a flange portion 3b formed continuously with the hub body 3 a. The hub body 3a has a tapered structure with a diameter gradually decreasing toward the tip of the hub body. The base end portion of the needle tube 2 is fixed to the distal end portion of the needle hub body 3 a. The flange portion 3b is formed at the base end portion of the needle hub body 3 a. The stabilizer 4 abuts the flange portion 3b in such a manner as to be fixed to the flange portion 3 b. The needle hub 3 may be of any form as long as the needle hub 3 can be connected to a syringe.

The syringe 9 may be a syringe filled with a medicament when the medicament injection device is used or a pre-filled syringe previously filled with a medicament. Examples of the medicament filled in the syringe 9 include a vaccine. However, hormones and agents using macromolecular substances such as cytokines may be filled in the syringe 9.

The stabilizer 4 has a shape in which two cylinders having different diameters continue in the axial direction. The stabilizer 4 includes a fixing portion 5 and a contact portion 6 formed continuously with the fixing portion 5, the fixing portion 5 forming one end portion of the stabilizer 4, and the contact portion 6 forming the other end portion of the stabilizer 4. The material of the stabilizer 4 may be synthetic resin (plastic) such as polycarbonate, polypropylene, polyethylene, or metal such as stainless steel, aluminum, or the like.

The fixing portion 5 of the stabilizer 4 is formed of a cylinder having a tube hole 5 a. One end of the fixing portion 5 is continuous with the contact portion 6. The other end of the fixing portion 5 is fixed to the flange portion 3b of the needle hub 3 by a fixing member such as an adhesive. In addition, the hub body 3a of the hub 3 is accommodated in the tube hole 5a of the fixing portion 5.

The contact portion 6 of the stabilizer 4 is formed of a cylinder having a larger diameter than the fixing portion 5, and has a tube hole 6a communicating with the tube hole 5a of the fixing portion 5. The pipe hole 6a of the contact portion 6 has a larger diameter than the pipe hole 5a of the fixing portion 5. The needle tube 2 held by the hub 3 is disposed in the tube hole 6a of the contact portion 6. Further, the center line of the tube hole 6a coincides with the axis of the needle tube 2.

When the upper layer portion of the skin is pierced with the needle tube 2, the end surface 6b of the contact portion 6 comes into contact with the skin surface and is pressed against the skin surface. When the end face 6b of the contact portion 6 is pressed against the skin, the skin forms a protrusion in the tubular hole 6a of the contact portion 6. In other words, the stabilizer 4 has a function of a skin deformer that deforms the skin. In addition, the needle tube 2 pierces a protrusion formed in the tube hole 6a of the skin.

The guide portion (which is a distance identifier) 7 and the outer peripheral surface of the contact portion 6 are integrally formed. The guide portion 7 protrudes from the contact portion 6 in the radial direction, and is formed in an annular shape continuous in the circumferential direction of the contact portion 6. In other words, the guide portion 7 is a flange portion protruding from the outer peripheral surface of the contact portion 6. The guide portion 7 has a contact surface 7a parallel to the end surface 6b of the contact portion 6. By pressing the contact portion 6 until the contact surface 7a contacts the skin, the pressing-in distance of the contact portion 6 into the skin can be always kept constant. In other words, the guide portion 7 has a function of recognizing the press-in distance of the contact portion 6 into the skin.

As a result, the height of the protruding portion of the skin formed in the tube hole 6a of the contact portion 6 can be made substantially constant. The depth of insertion of the needle tube 2 into the skin is equal to the sum of the height of the skin protrusion and the distance from the end face 6b of the contact portion 6 to the needlepoint of the needle tube 2. Therefore, by making the height of the skin protrusion substantially constant, the insertion depth of the needle tube 2 into the skin can be made constant.

In the present embodiment, the stabilizer 4 and the guide portion 7 are integrally formed with each other. However, the distance identifier of the present invention may also be formed separately from the skin deformer. In this case, the guide portion (distance identifier) is fixed to the skin deformer by a fixing member such as a screw, an adhesive, or the like.

Hereinafter, the distance between the end surface 6b of the contact portion 6 and the tip of the needle hole 2b of the needle tube 2 is referred to as "needle projection length L". In addition, hereinafter, the height of the skin protrusion from the end surface 6b is referred to as "skin protrusion length z" (see fig. 3), and the sum of the needle protrusion length L and the skin protrusion length z is referred to as "insertion length P". In addition, hereinafter, the length of the contact surface 7a of the guide portion 7 in the direction perpendicular to the outer peripheral surface of the contact portion 6 is referred to as "guide portion length (identifier length) x", and the distance between the end surface 6b of the contact portion 6 and the contact surface 7a of the guide portion 7 is referred to as "guide portion height (identifier height) y".

The guide portion length x is also a protruding length of the guide portion 7 protruding from the contact portion 6. The guide height y is considered when setting the guide length x. This is because if the guide portion length x is increased not in proportion to the increase in the guide portion height y, the press-in distance by which the end surface 6b of the contact portion 6 is pressed into the skin will increase.

The needle protrusion length L is positive when the needlepoint of the needle tube 2 protrudes from the end face 6b of the contact portion 6, and negative when the needlepoint of the needle tube 2 is located in the tube hole 6a of the contact portion 6. The needle protrusion length L may be set appropriately by changing the length of the needle tube 2 and/or changing the length of the needle hub 3 holding the needle tube 2, or the like. In order to reduce the risk of an undesired needle stick injury accident, it is preferred that the needle tip of the needle cannula 2 does not protrude from the end face 6 b.

The needle protrusion length L is determined based on the insertion length P and the skin protrusion length z (L ═ P-z). The insertion length P is set within the range of the thickness of the skin layer portion. On the other hand, by performing the following experiment, it was found that the skin protrusion length z varies with the changes in the guide portion length x and the guide portion height y. Therefore, the needle protrusion length L can be determined by the skin protrusion length z set based on the guide length x and the guide height y.

Here, the thickness of the upper layer portion of the skin will be described. As described above, the upper layer of the skin refers to the epidermis and dermis of the skin. The thickness of the upper layer of the skin is usually in the range of 0.5mm to 3.0 mm. Therefore, the insertion length P may be set in the range of 0.5mm to 3.0 mm.

Typically, the injection site for the influenza vaccine is the deltoid muscle. Therefore, the thickness of the upper layer part of the skin above the deltoid muscle was measured for 19 children and 31 adults. This measurement was performed by imaging the upper layer part of the skin having a High ultrasonic wave reflectance using an ultrasonic measuring device (NP 60R-UBM High Resolution Echo for small animals manufactured by NEPA GENE, co., ltd.). Incidentally, since the measured values are lognormal (lognormal) distributed, the range of MEAN ± 2SD is obtained by geometric averaging.

The results showed that the thickness of the upper layer of skin on the deltoid muscle of children was 0.9mm to 1.6 mm. The results also show that the thickness of the upper layer of the skin on the adult human deltoid muscle is 1.4mm to 2.6mm in the distal part (digital part), 1.4mm to 2.5mm in the middle part, and 1.5mm to 2.5mm in the proximal part (proximal part). From the above, it was confirmed that the thickness of the upper layer part of the skin on the deltoid muscle of the child was 0.9mm or more and the thickness of the upper layer part of the skin on the deltoid muscle of the adult was 1.4mm or more. Therefore, when injecting the upper part of the skin on the upper surface of the deltoid muscle, the insertion length P is preferably set to a range of 0.9mm to 1.4mm at the maximum.

In addition, by setting the insertion length P in this way, it is possible to ensure positioning of the blade face 2a on the upper layer portion of the skin. As a result, a pinhole (drug solution discharge port) 2b that opens in the blade face 2a can be positioned in the upper layer portion of the skin regardless of the position of the drug solution discharge port in the blade face 2 a. Incidentally, even if the medical fluid discharge port is located in the upper layer portion of the skin, if the needle tip is inserted to a depth deeper than the upper layer portion of the skin, the medical fluid flows into the subcutaneous tissue from between the side surface of the needle tip portion and the pierced skin, and therefore, it is important to ensure that the blade surface and the needle tip of the needle tube 2 are positioned in the upper layer portion of the skin.

Incidentally, although it is preferable that the bevel portion be positioned in the skin when inserted, if the gauge of the needle cannula is larger than 26G, it will be difficult to make the bevel length B1.0 mm or less. Therefore, in order to set the insertion length P in a preferable range (0.9mm to 1.4mm), it is preferable to use a needle tube smaller than 26G.

Next, the diameter of the tube hole 6a of the contact portion 6 will be described below. Hereinafter, the diameter of the pipe hole 6a is referred to as "inner diameter d".

Generally, when about 100 μ L of a drug solution is injected into the upper layer of the skin, a blister (blister) with a diameter of about 9mm to 12mm is formed in the skin. Therefore, in order that the stabilizer 4 does not interfere with the formation of the blister, it is preferable to set the inner diameter d to 12mm or more, and when the contact portion 6 is pressed against the skin to inject the drug, the size of 12mm or more does not interfere with the formation of the blister. However, even if the inner diameter is set to 8mm smaller than the blister diameter, blisters may be formed in tube hole 6a and a medicament may also be injected. Incidentally, an upper limit is not particularly set for the inner diameter d as long as the inner diameter d is 8mm or more. However, if the inner diameter d is set excessively large, both the outer diameter of the stabilizer 4 and the outer diameter of the guide portion 7 are large.

If both the outer diameter of the stabilizer 4 and the outer diameter of the guide portion 7 are large, it will be difficult to bring the guide portion 7 into contact with the skin when the needle cannula 2 penetrates the arm, for example. Therefore, in consideration of the thin arm of the child, it is preferable that the outer diameter of the guide portion 7 is set to about 30mm at maximum. Here, if the width of the end face of the contact portion 6 is 0.5mm and the guide portion length x is 0.5mm (which is considered to be the minimum value), the inner diameter d is 28mm at the maximum.

The outer diameter of the guide portion 7 is determined based on the width, inner diameter d, and guide portion length x of the end surface of the contact portion 6. In the present embodiment, the width of the end face of the contact portion 6 is set to 0.5 mm. The inner diameter d is set to be in the range of 11mm to 14mm, and the guide portion length x is set to be in the range of 0.5mm to 6.0 mm. Therefore, the outer diameter of the guide portion 7 is in the range of 13mm to 27mm, whereby the contact portion 7a of the guide portion 7 can be brought into contact with the skin.

[ method of Using drug injection device ]

Next, a method of using the medicine injection device to which the injection needle assembly 1 is applied will be described with reference to fig. 3.

First, the end surface 6b of the contact portion 6 of the stabilizer 4 is made to face the skin to be pierced by the needle tube, whereby the needlepoint of the needle tube 2 is made to face the skin to be pierced. Next, the medicament injection device is moved substantially perpendicular to the skin, and the end face 6b of the contact face 6 is pressed against the skin.

At this time, if the needlepoint of the needle tube 2 protrudes from the end face 6b of the contact portion 6, the needlepoint will first contact the skin before the end face 6b contacts the skin, however, the skin is slightly recessed by being pressed by the needle tube 2, rather than being immediately penetrated by the needle tube 2. However, if the needlepoint of the needle tube 2 is located in the tube hole 6a of the contact portion 6, the needlepoint of the needle tube 2 will contact the skin after the end face 6b of the contact surface 6 contacts the skin.

In addition, when the end face 6b of the contact portion 6 is pressed against the skin, a skin protrusion is formed in the tube hole 6a of the contact portion 6. In other words, the skin to be penetrated by the needle cannula 2 protrudes. At this time, the needle tip of the needle tube 2 penetrates the skin. In addition, when the contact portion 6 is pressed until the guide portion 7 contacts the skin, the press-in distance by which the contact portion 6 is pressed into the skin reaches a predetermined value. Thus, by bringing the guide portion 7 into contact with the skin, the pressing-in distance by which the contact portion 6 can be pressed into the skin is always constant, and therefore the skin protrusion length z can be made substantially constant. Here, the skin penetration distance is defined as one of the pressurization parameters when puncturing the skin.

By making the skin protrusion length z substantially constant, the insertion depth of the needle tube 2 into the skin can be made substantially constant. Therefore, if the skin protrusion length z is considered when setting the needle protrusion length L, both the needlepoint of the needle tube 2 and the tip of the needle hole 2b can be reliably positioned at the skin layer portion. For example, when the skin protrusion length z is set to 0.8mm, the needle protrusion length L is set to 0.4 mm. As a result, the insertion length P becomes 1.2mm, and thereby the tip of the needle hole 2b of the needle tube 2 can be positioned in the range of the thickness of the skin layer portion.

Thereafter, the medical fluid is discharged from the needle hole 2b of the needle tube 2 by operating the syringe 9 connected to the needle hub 3. As a result, the medical solution is injected into the upper layer portion of the skin.

[ test examples ]

Next, a test example of measuring the height of the protruding portion of the skin formed in the tube hole 6a of the contact portion 6 (i.e., the skin protrusion length z) and the press-in distance of the contact portion 6 into the skin (corresponding to the guide portion height y) will be described with reference to fig. 4A to 9.

Fig. 4A and 4B are diagrams illustrating a measuring apparatus for measuring the skin-protrusion length z and the guide portion height y. Fig. 5 is a graph showing measured values of the skin protrusion length z and the guide portion height y obtained by changing the inner diameter d. Fig. 6 is a graph showing the measured values of the skin-protrusion length z obtained by changing the guide height y and the inner diameter d. Fig. 7 is a graph showing the height of the skin protrusion (skin protrusion length z) and the distance (moving distance of the outer tube) corresponding to the identifier height (guide height y) measured using the measuring device shown in fig. 4A and 4B, which are obtained by changing the identifier length (guide length x). Fig. 8 is a graph showing the height of the skin protrusion measured using the measuring device shown in fig. 4A and 4B, in which the measured value is obtained by changing the length of the identifier and the moving distance of the outer tube corresponding to the height of the identifier. Fig. 9 is a diagram showing the relationship between the height of the identifier and the height of the skin protrusion.

First, the measuring apparatus 100 used in the present test will be explained below. The measuring device 100 is formed by cutting synthetic resin (plastic). The measuring apparatus 100 includes an outer tube 101 formed in a cylindrical shape and a pressing member 102 installed in the outer tube 101 in such a manner that: the pressing member 102 can slide along the tube hole 101a of the outer tube 101.

A flange portion 103 protruding in the radial direction of the outer tube 101 is provided at one end portion (lower end portion) of the outer tube 101. The bottom surface 103a of the flange portion 103 is coplanar with the end surface of the outer tube 101. The flange portion 103 corresponds to the guide portion 7 of the needle assembly 1 (see fig. 1). Further, the length between the outer peripheral surface of the flange portion 103 and the inner surface of the outer tube 101 corresponds to the guide portion length x of the needle assembly 1.

The pressing member 102 is formed of a cylindrical body having a diameter substantially the same as that of the tube hole 101a of the outer tube 101, and has a top surface 102a and a bottom surface 102 b. A circular recess 104 is formed in the bottom surface 102b of the pressing member 102. The diameter of the recess 104 corresponds to the inner diameter d of the needle assembly 1. The measuring member 105 is slidably mounted to the recess 104. The measuring member 105 is formed of a cylinder having a diameter substantially the same as that of the recess 104, and has a top surface 105a and a bottom surface 105 b.

On the other hand, since the recess 104 is provided, the bottom surface 102b of the pressing member 102 is formed in an annular shape. The bottom surface 102b of the pressing member 102 corresponds to the end surface 6b of the contact portion 6 of the needle assembly 1. Incidentally, in the measuring apparatus 100 used in the present experiment, the width of the bottom surface 102b of the pressing member 102 was set to 0.5 mm.

In order to measure the skin protrusion length z and the guide portion height y using the measuring device 100 having the above-described configuration, the measuring device 100 is first mounted on the skin as shown in fig. 4A. At this time, the bottom surface 103a of the flange portion 103 provided on the outer tube 101, the bottom surface 102b of the pressing member 102, and the bottom surface 105b of the measuring member 105 are all in contact with the skin.

Next, as shown in fig. 4B, the top surface 102a of the pressing member 102 is pressed, whereby the pressing member 102 is moved relative to the tube hole 101a of the outer tube 101, so that the bottom surface 102B of the pressing member 102 is pressed against the skin. As a result, the outer tube 101 and the pressing member 102 form the same configuration as the configuration of the stabilizer 4 in the state where the contact portion 6 is pressed against the skin.

When the bottom surface 102b of the pressing member 102 is pressed against the skin, a skin protrusion is formed in the recess 104, whereby the measuring member 105 is pushed up by the skin protrusion. In this state, the distance between the bottom surface 102b of the pressing member 102 and the bottom surface 105b of the measuring member 105 corresponds to the height of the protrusion of the skin (skin protrusion length z) caused by the stabilizer 4 of the needle assembly 1. Therefore, the skin protrusion length z can be measured by measuring the distance between the bottom surface 102b of the pressing member 102 and the bottom surface 105b of the measuring member 105.

Further, the distance between the bottom surface 102b of the pressing member 102 and the bottom surface 103a of the flange portion 103 corresponds to the guide portion height y of the needle assembly 1. Therefore, the guide portion height y can be measured by measuring the distance between the bottom surface 102b of the pressing member 102 and the bottom surface 103a of the flange portion 103.

In this test, the skin protrusion length z and the leading portion height y of the skin above the deltoid were measured for 10 adults. In the present test, first, the skin protrusion length z and the guide portion height y were measured using four measuring devices 100, wherein the diameters (inner diameters d) of the concave portions 104 of the four measuring devices 100 were 11mm, 12mm, 13mm, and 14mm, respectively. Incidentally, the guide portion length x is set to 0.5 mm. The upper limit of the force pressing the pressing member 102 is set to 20N, which is considered as the maximum usage value in practical use. By performing this measurement, it can be confirmed whether the skin-protrusion length z varies with the inner diameter d. The test results are shown in fig. 5.

As shown in fig. 5, in the case where the pressing member 102 is pressed against the skin with the application of a force of 20N, the skin protrusion length z ranges from 1.0mm to 1.3 mm. For example, when the inner diameter d is set to 11mm, the skin protrusion length z is about 1.1 mm. From the results, it is understood that when the inner diameter d is varied in the range of 11mm to 14mm, the skin protrusion length z is hardly affected by the variation of the inner diameter d. In addition, when the inner diameter d is set to 11mm, the guide portion height y becomes 2.6mm, and when the inner diameter d is set to a range of 12mm to 14mm, the guide portion height y becomes 1.5 mm.

Next, the skin protrusion length z was measured for both the cases where the pressing member 102 was pressed until the guide height y reached 1mm and 2mm, respectively. The results are shown in fig. 6. When the guide height y is 1mm, the skin protrusion length z is in the range of 0.5mm to 0.7mm when the inner diameter d is in the range of 11mm to 14 mm. When the inner diameter d is 12mm, the skin protrusion length z reaches a maximum of about 0.7 mm. In addition, in the case where the guide portion height y is 2mm, the skin protrusion length z is about 0.8mm when the inner diameter d is 11 mm.

Next, since the skin-protrusion length z under a pressure of 20N is about 1.2mm regardless of the variation of the inner diameter d, the inner diameter d is set to 12mm, and the skin-protrusion length z and the guide height y are measured by varying the guide length x in the range of 0.5mm to 5 mm. The test results are shown in fig. 7.

First, the force pressing the pressing member 102 was set to 20N, and the skin protrusion length z and the guide portion height y were measured. As shown in fig. 7, as the guide length x increases, the guide height y increases. Similarly, the skin protrusion length z is in the range of 1.0mm to 1.2 mm.

Next, the skin protrusion length z was measured by changing the guide portion height y in the range of 1mm to 8 mm. The results are shown in fig. 8. As the guide height y increases, the skin protrusion length z increases. It can thus be seen that the skin-protrusion length z varies approximately proportionally to the guide height y (see fig. 9). Thereby, the skin protrusion length z can be set based on the guide portion height y.

Fig. 9 is a diagram showing the relationship between the guide portion height y and the skin protrusion length z (the height of the skin protrusion). As is apparent from fig. 9, for example, when the guide length x is 3mm, the skin protrusion length z and the guide height y satisfy a relationship defined by the following expression.

Z is 0.104y +0.097 (correlation coefficient 0.99)

Further, when the guide portion length x is 5mm, the skin protrusion length z and the guide portion height y satisfy a relationship defined by the following expression.

Z is 0.090y +0.090 (correlation coefficient 0.98)

Incidentally, it can be said that the above two relations have substantially the same constant. In other words, it can be said that if each constant is rounded to the first decimal place, the skin-protrusion length z and the lead portion height y satisfy the relationship defined by the following expression.

Z＝0.1y+0.1

Therefore, when the guide portion length x is set in the range of 3.0mm to 5.0mm, the above relational expression can be applied.

In addition, when the guide portion length x is set to 0.5mm, the guide portion height y may be set to 1mm, but the guide portion height y cannot be set to 2mm or more. In other words, although it is attempted to press the pressing member 102 against the skin until the guide portion height y reaches 2mm, the bottom surface 103a of the flange portion 103 does not contact the skin. From this, it is understood that when the guide portion length x is set to 0.5mm, the guide portion height y should be set to 1mm or less. Likewise, it can be understood that when the guide length x is set to 1.0mm, the guide height y should be set to 2mm or less.

Based on the above test results, it can be understood that the insertion length P (see fig. 3) can be defined by changing the guide height y. For example, if the guide length x is set to 0.5mm and the guide height y is set to 1.5mm, the skin protrusion length z will become about 1.2 mm. Therefore, if the needle-projecting length L is set to 0.2mm, the insertion length P may be set to 1.4(1.2+0.2 ═ 1.4) mm, thereby enabling the tip of the needle cannula 2 to be reliably positioned at the upper layer portion of the adult skin. In addition, if the needle-projecting length L is set to-0.3 mm, the insertion length may be set to 0.9(1.2-0.3 ═ 0.9) mm, whereby the tip of the needle cannula 2 can be reliably positioned at the upper layer portion of the skin of the child.

In addition, when the guide portion length x is in the range of 3.0mm to 5.0mm and the inner diameter d is in the range of 11mm to 14mm, the guide portion height y and the skin protrusion length z satisfy the following relation: z is a relationship defined by 0.1y + 0.1. Thus, the skin protrusion length z may be defined according to this relation. In addition, the needle protrusion length L (L ═ P-z) may be determined based on the defined skin protrusion length z and insertion length P.

2. Second embodiment

Hereinafter, an injection needle assembly and a medicament injection device according to a second embodiment of the present invention will be described with reference to fig. 10.

The needle assembly 11 has the same configuration as that of the needle assembly 1 of the first embodiment except for the stabilizer 14 and the guide portion 17. Therefore, in the second embodiment, only the stabilizer 14 and the guide portion 17 are explained, and the same components as those of the injection needle assembly 1 are denoted by the same reference numerals and the explanation thereof is omitted.

Incidentally, the medicine injection device of the present invention is formed by connecting the syringe 9 (see fig. 3) and the hub 3 of the injection needle assembly 11.

The stabilizer (which is a skin deformer) 14 has a shape in which two cylinders having different diameters are continued in the axial direction. The stabilizer 14 includes a fixing portion 15 and a contact portion 16 formed continuously with the fixing portion 15, the fixing portion 15 forming one end portion of the stabilizer 14, and the contact portion 16 forming the other end portion of the stabilizer 14. The material of the stabilizer 14 may be synthetic resin (plastic) such as polycarbonate, polypropylene, polyethylene, or metal such as stainless steel, aluminum, or the like.

The fixing portion 15 of the stabilizer 14 has the same shape as the fixing portion 5 of the first embodiment, and is formed of a cylinder having a tube hole 15 a. One end of the fixing portion 15 is fixed to the flange portion 3b of the needle hub 3 by a fixing member such as an adhesive. The other end of the fixed portion 15 is continuous with the contact portion 16. In addition, the hub body 3a of the hub 3 is accommodated in the tube hole 15a of the fixing portion 15.

The contact portion 16 of the stabilizer 14 is formed of a cylinder having a diameter larger than that of the fixing portion 15, and has a tube hole 16a communicating with the tube hole 15a of the fixing portion 15. The diameter of the tube hole 16a is larger than the diameter of the tube hole 15a of the fixing portion 15. The needle tube 2 held by the needle hub 3 is accommodated in the tube hole 16a of the contact portion 16. Further, the center line of the tubular hole 16a coincides with the axis of the needle tube 2.

When the upper layer portion of the skin is pierced with the needle tube 2, the end face 16b of the contact portion 16 is brought into contact with and pressed against the skin surface. When the end face 16b is pressed against the skin, a skin protrusion is formed in the tube hole 16a of the contact portion 16. In addition, the needle tube 2 pierces a skin protrusion formed in the tube hole 16 a.

A guide portion (which is a distance identifier) 17 is provided at an end of the contact portion 16. The guide portion 17 is formed by cutting an end surface 16b of the contact portion 16 to form a step portion, and has a contact surface 17a and a wall surface 17 b.

The contact surface 17a of the guide portion 17 is a flat surface parallel to the end surface 16b of the contact portion 16, and is formed in an annular shape continuous in the circumferential direction of the contact portion 6. The distance between the contact surface 17a and the end surface 16b of the contact portion 16 corresponds to the "guide portion height y" of the first embodiment. The wall surface 17b is a curved surface continuously extending in the circumferential direction of the contact portion 16. The distance between the wall surface 17b and the outer peripheral surface of the contact portion 16 corresponds to the "guide portion length x" of the first embodiment. In other words, the length of the contact surface 17a in the direction perpendicular to the outer peripheral surface of the contact portion 16 corresponds to the "guide portion length x".

With the syringe assembly 11 having this configuration, the same functions and advantages as those of the syringe assembly 1 of the foregoing first embodiment can also be achieved. Specifically, by pressing the contact portion 16 until the contact surface 17a of the guide portion 17 contacts the skin, the pressing-in distance of the contact portion 16 into the skin can be always kept constant.

As a result, the height of the skin protrusions formed in the pore 16a of the contact portion 16 can be made substantially constant. The depth of insertion of the needle tube 2 into the skin is equal to the sum of the height of the skin protrusion and the distance from the end face 16b of the contact portion 16 to the needlepoint of the needle tube 2. Therefore, by making the height of the skin protrusion substantially constant, the depth of insertion of the needle tube 2 into the skin can be made substantially constant.

3. Third embodiment

Hereinafter, an injection needle assembly and a medicament injection device according to a third embodiment of the present invention will be described with reference to fig. 11.

The needle assembly 21 has the same configuration as that of the needle assembly 1 of the first embodiment except for the guide portion (as a distance identifier) 27. Therefore, in the third embodiment, only the guide portion 27 will be described, and the same components as those of the needle assembly 1 are denoted by the same reference numerals and the description thereof will be omitted.

Incidentally, the injection needle assembly 21 has the same hub 3 as that provided in the first embodiment (see fig. 1). Further, the medicament injection apparatus of the present invention is formed by connecting the syringe 9 (see fig. 3) and the hub 3 of the injection needle assembly 21.

The guide portion 27 of the needle assembly 21 is a scale marked on the contact portion 6. The guide portion 27 is formed on the contact portion 6 by printing or spraying. Incidentally, printing or spraying may be applied to the outer peripheral surface of the contact portion 6, or to the inner peripheral surface of the contact portion 6. The guide portion 27 is formed continuously in the circumferential direction of the contact portion 6, and thus can be recognized from any direction. The distance between the guide portion 27 and the end surface 6b of the contact portion 6 corresponds to the "guide portion height y" of the first embodiment.

With the syringe assembly 21 having this configuration, the same functions and advantages as those of the syringe assembly 1 of the foregoing first embodiment can also be achieved. Specifically, by pressing the contact portion 6 until the guide portion (scale) 27 is aligned with the skin surface around the contact portion 6, the pressing-in distance of the contact portion 6 into the skin can be always kept constant.

As a result, the height of the skin protrusions formed in the tube holes 6a of the contact portion 6 can be made substantially constant. The insertion depth of the needle tube 2 into the skin is equal to the sum of the height of the skin protrusion formed in the tube hole 6a and the distance from the end face 6b of the contact portion 6 to the needlepoint of the needle tube 2. Therefore, by making the height of the skin protrusion substantially constant, the depth of insertion of the needle tube 2 into the skin can be made substantially constant.

Although the guide portion 27 is formed on the contact portion 6 by printing or insertion in the present embodiment, the guide portion 27 may be formed by other methods. For example, the guide portion 27 may alternatively be provided by forming a groove in the contact portion 6 or by bonding a sheet on the contact portion 6.

Although only one guide portion (scale) 27 is provided as the distance identifier in the present embodiment, the injection needle assembly according to the present invention may be provided with more than two distance identifiers (scales). For example, the injection needle assembly may be provided with a distance identifier (scale) for adults and a distance identifier (scale) for children. In this case, the height y of the guide portion of the distance recognizer for adults is higher (larger) than the height y of the guide portion of the distance recognizer for children, and the insertion depth of the needle tube 2 into the upper layer portion of the skin of an adult is deeper than the insertion depth of the needle tube 2 into the upper layer portion of the skin of a child. Therefore, the insertion depth of the needle tube 2 into the upper layer of the skin can be changed according to the thickness of the upper layer of the skin, and therefore, the needlepoint of the needle tube 2 can be reliably positioned on the upper layer of the skin.

4. Fourth embodiment

Hereinafter, an injection needle assembly and a medicament injection device according to a fourth embodiment (hereinafter referred to as "the present embodiment") of the present invention will be described with reference to fig. 12 to 14. Incidentally, in the present embodiment, the description of the same components as those of the first, second, and third embodiments will be omitted.

Fig. 12 is a schematic view showing an injection needle assembly according to the present embodiment, and fig. 13 is a perspective view showing the injection needle assembly according to the present embodiment. Fig. 14 is a view for explaining a use state of the medicine injection device according to the present embodiment.

As shown in fig. 12 and 13, the injection needle assembly 31 includes a hollow needle tube 2, a needle hub 3 holding the needle tube 2, a stabilizer 4, and an adjusting portion 34 fixed to the needle tube 2. In addition, the medicament injection device of the present invention is constructed by connecting the syringe 9 and the needle hub 3 (see fig. 14).

The needle cannula 2 may be a straight needle or a needle with at least a part of a tapering cone or the like. The tapered needle may have the following configuration: the base end portion fixed to the needle hub 3 has an outer diameter larger than that of the tip end portion including the needle tip, and an intermediate portion is tapered. In addition, by disposing the adjustment portion in the tapered portion, the adjustment portion 34 is prevented from moving toward the base end due to the slope of the tapered portion. With this configuration, even if the needle-projecting face is pressed hard against the skin, the length of the needle tip projecting from the needle-projecting face does not change, and therefore a predetermined depth of penetration of the needle into the skin can be secured.

The tube bore of the needle tube 2 communicates with the needle hub 3. The hub 3 includes a hub body 3a holding the needle tube 2 and a flange portion 3b formed continuously with the hub body 3 a. The hub body 3a has a tapered structure with a diameter gradually decreasing toward the tip of the hub body. The base end portion of the needle tube 2 is fixed to the distal end portion of the needle hub body 3 a. The flange portion 3b is formed at the base end portion of the needle hub body 3 a. The stabilizer 4 is fixed to the flange portion 3 b. The needle hub 3 may be of any form as long as the needle hub 3 can be connected to a syringe.

The adjustment portion 34 is formed in a cylindrical shape. The needle tube 2 penetrates the regulating portion 34, and the axis of the needle tube 2 and the axis of the regulating portion 34 coincide with each other. The regulating portion 34 is fixed in close contact with the outer peripheral surface of the needle tube 2. One end surface of the regulating portion 34 forms a hub opposing surface 34a opposing the hub 3, the other end surface of the regulating portion 34 forms a flat needle projecting surface 34b, and the needlepoint of the needle tube 2 projects from the needle projecting surface 34 b.

An adhesive recess 34c is provided in the hub opposing surface 34a of the adjustment portion 34 so as to surround the outer periphery of the needle tube 2. The regulating portion 34 is fixed in close contact with the outer peripheral surface of the needle tube 2 by applying the adhesive 35 in the adhesive recess 34c in a state where the needle tube 2 has penetrated the regulating portion 34. Examples of the adhesive 35 include cyanoacrylate resin, epoxy resin, photo-curable resin, and the like. However, a material made of other resins may be used as the adhesive 35.

When the upper layer portion of the skin is pierced with the needle tube 2, the needle-projecting surface 34b of the regulating portion 34 comes into contact with the skin surface, thereby defining the insertion depth of the needle tube 2. In other words, the insertion depth of the needle tube 2 into the skin is determined by the length of the needle tube 2 protruding from the needle-protruding face 34b (hereinafter referred to as "needle-protruding length L").

As described above, the thickness of the upper layer of the skin corresponds to the depth from the skin surface to the dermis layer, and is usually in the range of 0.5mm to 3.0 mm. Therefore, the needle-projecting length L of the needle tube 2 can be set in the range of 0.5mm to 3.0 mm. Therefore, in the injection into the upper part of the skin above the deltoid muscle, the preferable needle-projecting length L of the needle tube 2 can be set in the range of 0.9mm to 1.4 mm.

In addition, by setting the needle tube 2 in this way, the blade face 2a can be reliably positioned at the upper layer portion of the skin. As a result, the medical fluid discharge port that opens in the blade face 2a can be positioned at the upper layer portion of the skin regardless of the position of the medical fluid discharge port in the blade face 2 a. Incidentally, even if the medical fluid discharge port is located in the upper layer portion of the skin, if the needle tip is pierced to a depth deeper than the upper layer portion of the skin, the medical fluid flows from the upper layer portion of the skin into the subcutaneous tissue from between the side surface of the needle tip portion and the pierced skin. It is therefore important to ensure that both the tip and the facet of the needle cannula 2 are positioned in the upper layer of the skin.

Incidentally, in the case where the gauge of the needle tube is larger than 26G, it is difficult to make the bevel length B1.0 mm or less. Therefore, in order to set the needle protrusion length L of the needle tube 2 in a preferable range (0.9mm to 1.4mm), it is preferable to use a needle tube of less than 26G.

The needle projecting surface 34b of the regulating portion 34 is formed as follows: the distance S from the peripheral edge of the needle-projecting surface 34b to the outer peripheral surface of the needle tube 2 is 1.4mm or less, preferably in the range of 0.3mm to 1.4 mm. The distance S from the peripheral edge of the needle-projecting surface 34b to the outer peripheral surface of the needle tube 2 is set by taking into account that the needle-projecting surface 34b presses the skin around the needle tube 2 to apply pressure to the blister formed in the upper layer of the skin. Thus, even if the needle projecting surface presses the skin around the needle tube 2, leakage of the injected medicine can be prevented.

As the material of the adjustment portion 34, for example, synthetic resin (plastic) such as polycarbonate, polypropylene, polyethylene, or the like can be used, and as the material of the adjustment portion 34, metal such as stainless steel, aluminum, or the like can be used.

In the present embodiment, the regulating portion 34 is fixed to the needle tube 2 with the adhesive 35, but in the needle assembly according to the present invention, the regulating portion may be fixed to the needle tube 2 by other methods.

For example, in the case where the regulating portion 34 is formed of metal and fixed to the needle tube 2, the aforementioned other methods may include a method of caulking, welding, or the like. In addition, in the case where the regulating portion 34 is formed of synthetic resin and fixed to the needle tube 2, the aforementioned other methods may include welding and integral molding (in particular, insert molding) and the like.

The contact portion 6 is arranged to cover the outer peripheries of the needle tube 2 and the regulating portion 34 by fixing the fixing portion 5 to the needle hub 3. Incidentally, in the present embodiment, the end surface 6b on the one axial end side of the contact portion 6 is substantially flush with the needle projecting surface 34b of the regulating portion 34. The needle tube 2 is perpendicular to a plane formed by the end surface 6b of the stabilizer 4 and the needle protruding surface 34b of the adjustment portion 34.

Therefore, as shown in fig. 14, when the needle tube 2 penetrates the living body, the needle-protruding surface 34b of the regulating portion 34 contacts the skin surface, and the end surface 6b of the stabilizer 4 also contacts the skin surface. Thereby, the needle tube 2 can be supported by the stabilizer 4 so as to be substantially perpendicular to the skin. As a result, the needle tube 2 can be prevented from wobbling, and the needle tube 2 can be made to penetrate the skin straightly.

Incidentally, the needle projecting surface 34b of the regulating portion 34 does not necessarily have to be flush with the end surface 6b of the stabilizer 4. In other words, the object of the present invention can be achieved when the needle projecting surface 34b of the regulating portion 34 is located on the other side (i.e., the side on which the fixing portion 5 is located) opposite to the side on which the end surface 6b is located in the axial direction of the stabilizer 4. In addition, in view of the skin protrusion formed when the stabilizer 4 is pressed against the skin, it is preferable that the axial distance between the needle-protruding surface 34b and the end surface 6b of the regulating portion 34 is set to 1.3mm or less.

The inner diameter d of the contact portion 6 of the stabilizer 4 is set to a value equal to or larger than the diameter of the blister formed in the skin. Specifically, the distance T between the inner wall of the contact portion 6 and the outer peripheral surface of the regulating portion 34 is set in the range of 4mm to 15 mm. Therefore, it is possible to prevent pressure from being applied to the blister from the inner wall of the stabilizer 4 to hinder the formation of the blister.

Incidentally, the distance T between the inner wall of the stabilizer 4 and the outer peripheral surface of the adjustment portion 34 is set to 4mm or more, but the upper limit of the distance T is not particularly set. However, if the distance T is too large, both the outer diameter of the stabilizer 4 and the outer diameter of the contact portion 6 become large. If the outer diameter of the contact portion 6 is large, it will be difficult to bring the end surface 6b of the contact portion 6 into contact with the skin when the needle tube 2 penetrates the skin of the small arm of the child. Therefore, in consideration of the thin arm of the child, it is preferable to limit the distance T between the inner wall of the stabilizer 4 (contact portion 6) and the outer peripheral surface of the adjustment portion 34 to 15mm at maximum.

In addition, if the distance S between the peripheral edge of the needle-projecting surface 34b of the regulating portion 34 and the outer peripheral surface of the needle tube 2 is 0.3mm or more, the regulating portion 34 will not be able to pierce the skin. Therefore, the inner diameter d of the contact portion 6 may be set to 9mm or more in consideration of the diameter of the needle tube 2 (about 0.3mm) and the distance T (4mm or more) between the inner wall of the contact portion 6 and the outer peripheral surface of the regulating portion 34.

In addition, the guide portion 7 is formed integrally with the outer peripheral surface of the contact portion 6 of the stabilizer 4. By pressing the stabilizer 4 until the contact surface 7a of the guide portion 7 contacts the skin, the force for pressing the skin applied from the stabilizer 4 and the needle tube 2 can be kept at a predetermined value or more at all times, whereby the projecting portion (corresponding to the needle projecting length L) of the needle tube 2 projecting from the needle projecting surface 34b can be surely inserted into the skin.

In addition, the length (guide height) y of the distance between the contact surface 7a of the guide 7 and the end surface 6b of the stabilizer 4 is set so that the skin can be pierced by appropriate pressure applied from the needle tube 2 and the stabilizer 4. Incidentally, a suitable pressure to be applied from the needle tube 2 and the stabilizer 4 is, for example, in the range of 0.5N to 20N. As a result, the pressure applied to the skin from the needle tube 2 and the stabilizer 4 can be guided to the user by the guide portion 7, and the needle tip and the blade face 2a of the needle tube can be reliably positioned at the upper layer portion of the skin, thereby giving a feeling of reassurance to the user.

Specifically, in the case where the inner diameter d of the stabilizer 4 is set in the range of 12mm to 14mm, the guide height y can be calculated by the following expression 1 based on the length (guide length) x between the protruding end surface of the guide 7 and the outer peripheral surface of the stabilizer 4.

[ expression 1]

1.0Ln(x)+1.2＜y＜3.1Ln(x)+3.2

Expression 1 is determined based on the results of the test examples described below.

Incidentally, in the case where the inner diameter d of the stabilizer 4 is 11mm, for example, when the guide portion length x is 0.5mm, the guide portion height y is set in the range of 0.75mm to 2.6 mm. Similarly to expression 1, this value was also determined based on the results of the test examples described below.

Incidentally, the shape of the stabilizer 4 is not limited to the cylindrical shape, and may be formed in a polygonal prism shape such as a quadrangular prism, a hexagonal prism, or the like having a tube hole at the center, for example. In addition, the stabilizer may also have a configuration in which the fixing portion 5 and the contact portion 6 have the same diameter.

In addition, although the present embodiment is explained based on the embodiment in which the stabilizer 4 is fixed to the needle hub 3, the stabilizer 4 may be fixed to the syringe 9 constituting the medicament injection apparatus. In addition, although in the present embodiment, the stabilizer 4 is fixed to the hub 3 with an adhesive, the injection needle assembly according to the present invention may have a configuration in which the stabilizer 4 is fixed to the hub 3 by other methods. For example, in the case where the stabilizer 4 is made of metal and fixed to the needle hub 3, the other methods described above may include caulking, welding, or the like. In addition, in the case where the stabilizer 4 is made of synthetic resin and is fixed to the needle hub 3, the above-mentioned other methods may include welding and integral molding (in particular, insert molding) or the like.

[ method of Using drug injection device ]

Next, a method of using the medicine injection device to which the injection needle assembly 31 is applied will be described below with reference to fig. 14.

First, the end surface 6b of the stabilizer 4 is made to face the skin, whereby the needlepoint of the needle tube 2 is made to face the skin to be punctured. Next, the needle assembly 31 is moved substantially perpendicularly to the skin, and the needle tube 2 penetrates the skin while the end face 6b of the stabilizer 4 is pressed against the skin. Here, the needle projecting surface 34b of the regulating portion 34 is flush with the end surface 6b of the stabilizer 4. Thereby, the needle projecting surface 34b of the regulating portion 34 can be brought into contact with the skin to deform the skin flatly, and the needle tube 2 can be inserted into the skin only by the needle projecting length L.

Next, the stabilizer 4 is pressed until the contact surface 7a of the guide portion 7 contacts the skin. Here, the value of the guide portion height y is set so that the needle tube 2 and the stabilizer 4 can pierce the skin with an appropriate pressure. Therefore, the force with which the stabilizer 4 is pressed against the skin becomes a predetermined value. Thus, the pressure of the stabilizer 4 can be directed to the user; the stabilizer 4 can be pressed against the skin with a suitable pressure; the needlepoint and the blade face 2a of the needle tube 2 can be reliably positioned on the skin layer portion. In this embodiment, since the guide portion 7 serves as a mark for guiding the pressure of the stabilizer 4, the needle tip of the needle tube can be reliably positioned on the upper layer portion of the skin, and the drug can be reliably injected into the upper layer portion of the skin, so that the user can be more relieved. Here, the pressure for pressing the stabilizer 4 until the guide portion 7 comes into contact with the skin is defined as a pressurization parameter when puncturing the skin.

In addition, by pressing the stabilizer 4 against the skin, the needle tube 2 can be stabilized, and the needle tube 2 can be made to pierce the skin straightly. Therefore, the needle tube 2 can be prevented from swinging, and the medicine can be stably injected. For example, when a very short needle having a projection length of about 0.5mm is used, there are cases where the needle is not inserted into the skin even if the needle tip is in contact with the skin. However, when the stabilizer 4 is pressed against the skin and the skin is pressed vertically downward, the skin inside the stabilizer 4 is deformed to be in a tensioned state. Therefore, since the skin becomes hard to escape from the needlepoint of the needle tube 2, the stabilizer 4 has an effect of making it easy for the needlepoint to pierce the skin.

Further, since the needle projecting length L is set in the range of 0.5mm to 3.0mm, the needlepoint and the blade face 2a of the needle tube 2 are reliably positioned on the skin layer portion. Thereafter, the medicament is injected into the upper layer of the skin using the syringe 9 connected to the needle hub 3.

The regulating portion 34 of the needle unit 31 is fixed in close contact with the outer periphery of the needle tube 2, and no gap is formed between the regulating portion 34 and the portion of the needle tube 2 passing through the regulating portion 34. Therefore, if the needle projecting surface 34b of the regulating portion 34 comes into contact with the skin, the skin around the needle tube 2 can be deformed flatly. As a result, the needle tube 2 can penetrate the skin only by the needle-projecting length L, and the needlepoint of the needle tube 2 can be reliably positioned on the skin layer portion.

Further, since the dimension of the needle projecting surface 34b of the regulating portion 34 and the inner diameter d of the stabilizer 4 are set to appropriate values, the injected drug can be prevented from leaking out of the body, and therefore, the drug can be reliably injected into the upper layer portion of the skin.

[ test examples ]

Next, a test example of measuring a pressing-in distance (corresponding to the guide portion height y) by which the stabilizer 4 is pressed into the skin when the stabilizer 4 is pressed against the skin at a predetermined pressure will be described below with reference to fig. 15A to 17.

Fig. 15A and 15B are diagrams illustrating a measuring device for measuring the guide height y. Fig. 16 is a graph showing the measurement value of the guide portion height y obtained by changing the inner diameter d of the contact portion 6. Fig. 17 is a diagram showing the measured value of the guide height y obtained by changing the guide length x.

First, the measuring apparatus 200 used in the present test will be explained below. The measuring device 200 is formed by cutting synthetic resin (plastic). The measuring device 200 includes an outer tube 101 formed in a cylindrical shape and a pressing member 102 slidably fitted in a tube hole 101a of the outer tube 101.

A flange portion 103 protruding in the radial direction of the outer tube 101 is provided at one end portion (lower end portion) of the outer tube 101. The bottom surface 103a of the flange portion 103 is coplanar with the end surface of the outer tube 101. The flange portion 103 corresponds to the guide portion 7 of the needle assembly 31 (see fig. 12). In addition, the radial thickness of the outer tube 101 including the flange portion 103 corresponds to the guide portion length x of the injection needle assembly 31.

The pressing member 102 is formed of a cylindrical body having a diameter substantially the same as that of the tube hole 101a of the outer tube 101, and has a top surface 102a and a bottom surface 102 b. A circular recess 104 is formed in the bottom surface 102b of the pressing member 102. The diameter of the recess 104 corresponds to the inner diameter d of the contact portion 6 of the stabilizer 4 of the needle assembly 31.

On the other hand, since the recess 104 is provided, the bottom surface 102b of the pressing member 102 is formed in an annular shape. The bottom surface 102b of the pressing member 102 corresponds to the end surface 6b of the stabilizer 4 of the needle assembly 31. Incidentally, in the measuring apparatus 200 used in the present experiment, the width of the bottom surface 102b of the pressing member 102 was set to 0.5 mm.

In order to measure the guide portion height y using the measuring device 200 having the above-described configuration, first, the measuring device 200 is mounted on the skin as shown in fig. 15A. At this time, the bottom surface 103a of the flange portion 103 provided on the outer tube 101 and the bottom surface 102b of the pressing member 102 come into contact with the skin.

Next, as shown in fig. 15B, the top surface 102a of the pressing member 102 is pressed with a predetermined force, whereby the pressing member 102 moves relative to the tube hole 101a of the outer tube 101, so that the bottom surface 102B of the pressing member 102 is pressed against the skin. As a result, the outer tube 101 and the pressing member 102 are formed in the same configuration as the stabilizer 4 in a state where the contact portion 6 is pressed against the skin.

When the bottom surface 102b of the pressing member 102 is pressed against the skin, a skin protrusion is formed in the recess 104. Further, the distance between the bottom surface 102b of the pressing member 102 and the bottom surface 103a of the flange portion 103 corresponds to the guide portion height y of the needle assembly 31. Therefore, the guide portion height y can be set by measuring the distance between the bottom surface 102b of the pressing member 102 and the bottom surface 103a of the flange portion 103.

In this experiment, the lead height y of the skin above the deltoid muscle, which is the injection site of the vaccine, was measured for 10 adults. In the present test, first, the guide portion height y was measured using four measuring devices 200, wherein the diameters of the concave portions 104 (the inner diameter d of the contact portion 6) of the four measuring devices 200 were 11mm, 12mm, 13mm, and 14mm, respectively. Incidentally, the guide portion length x is set to 0.5 mm. In addition, the pressure of the pressing member 102 was 0.5N and 20N. The pressures of 0.5N and 20N are the minimum and maximum pressure values, respectively, in practical applications. A pressure of 0.5N is the minimum pressure value that can puncture the skin, and when the pressure is less than 0.5N, it is impossible to puncture the skin. A pressure of 20N is the maximum pressure at which the medicament can be injected into the upper layer of the skin. If the pressure is greater than 20N, the skin will be pushed and deformed and the needle tip will reach the subcutaneous layer due to the excessive pressure applied to the regulating portion 34. Therefore, it would be difficult to inject the medicament into the upper layer of the skin. By performing this measurement, it can be confirmed whether or not the guide portion height y changes with a change in the inner diameter d of the contact portion 6. The test results are shown in fig. 16.

As shown in fig. 16, in the case where the inner diameter d of the contact portion 6 is 11mm, when the pressure is 0.5N, the guide portion height y becomes about 0.75 mm. And when the pressure was 20N, the guide height y became about 2.6 mm. From this, it can be understood that, in the case where the inner diameter d of the contact portion 6 is 11mm, when the guide portion length x is set to 0.5mm and the guide portion height y is set in the range of 0.75mm to 2.6mm, the guide portion 7 plays a guiding role when the needle assembly 31 is pressed against the skin with a pressure of 0.5N to 20N.

When the inner diameter d of the contact portion 6 is in the range of 12mm to 14mm, the guide portion height y is in the range of 0.6mm to 0.8mm when the pressure is 0.5N. And when the pressure is 20N, the height y of the guide part is in the range of 1.4 mm-1.5 mm. From this, it can be understood that in the case where the inner diameter d of the contact portion 6 is in the range of 12mm to 14mm, when the guide portion length x is set to 0.5mm and the guide portion height y is set in the range of 0.6mm to 1.5mm, the guide portion 7 plays a guiding role when the injection needle assembly 31 is pressed against the skin with a pressure of 0.5N to 20N.

Here, it is understood that the guide portion height y does not change much when the inner diameter d of the contact portion 6 is in the range of 12mm to 14 mm. Next, the guide height y was measured by changing the guide length x in the range of 0.5mm to 5mm with the inner diameter d of the contact portion 6 set to 12 mm. The test results are shown in fig. 17. Incidentally, the force pressing the pressing member 102 was set in the range of 0.5N to 20N, which is the same value as the above-described test.

As shown in fig. 17, when the guide length x increases, the guide height y increases regularly. From this, it can be understood that the guide height y and the guide length x are related to each other. In other words, it can be understood that the guide height y is proportional to the guide x. In addition, based on the present experiment, the relationship between the guide portion height y and the guide portion x defined by expression 1 was obtained.

[ expression 1]

1.0Ln(x)+1.2＜y＜3.1Ln(x)+3.2

From the above test results, it is understood that the guide height y (see fig. 14) can be determined by changing the guide length x. Incidentally, as described above, in the case where the inner diameter d of the contact portion 6 is in the range of 12mm to 14mm, the guide portion height y does not vary greatly. Therefore, in the case where the inner diameter d of the contact portion 6 is in the range of 12mm to 14mm, the guide portion height y may be set to a value that satisfies the relationship defined by expression 1. Thus, when the needle assembly 31 is pressed against the skin with a pressure of 0.5N to 20N, the guide portion 7 functions as a guide, and the needle tip and the blade surface 2a of the needle tube 2 can be reliably positioned on the skin layer portion, so that the user can be given more sense of reassurance.

Incidentally, the pressure for pressing the injection needle assembly 31 against the skin may be set in the range of 0.5N to 20N. This pressure range is confirmed by performing the following test: the test results, in which the medical solution was injected into the skin of the pig using a device without the guide portion 7 of the injection needle assembly 31 at a pressure of 0.5N to 20N, showed that the medical solution could be injected into the dermis without leakage.

5. Fifth embodiment

Next, an injection needle assembly according to a fifth embodiment of the present invention will be described below with reference to fig. 18.

Fig. 18 is a sectional view showing an injection needle assembly according to a fifth embodiment.

The injection needle assembly 41 according to the fifth embodiment has the same configuration as that of the injection needle assembly 31 (see fig. 12) of the fourth embodiment except for the stabilizer 14 and the guide portion 17. In addition, the stabilizer 14 and the guide portion 17 are the same as the stabilizer 14 and the guide portion 17 of the needle assembly 11 (see fig. 10) of the second embodiment. Therefore, in the present embodiment, the same components as those of the injection needle assembly 11 and the injection needle assembly 31 are denoted by the same reference numerals and the description thereof is omitted.

Similarly to the fourth embodiment, the medicament injection device of the present invention is formed by connecting the syringe and the hub 3 of the injection needle assembly 41.

The needle tube 2, the needle hub 3, and the adjustment portion 34 are disposed in the tube hole of the stabilizer 14. In addition, the stabilizer 14 includes a fixing portion 15 fixed to the needle hub 3 and a contact portion 16 covering the outer periphery of the needle tube 2 and the regulating portion 34.

The hub body 3a of the hub 3 is received in the tube hole 15a of the fixing portion 15. In addition, the contact portion 16 is arranged to cover the outer periphery of the needle tube 2 and the regulating portion 34 by fixing the fixing portion 15 to the needle hub 3.

The guide portion 17 is continuously formed in the circumferential direction of the outer peripheral surface of the stabilizer 14, and the guide portion 17 is formed as a stepped portion that is recessed substantially perpendicularly from the outer peripheral surface of the stabilizer 14 to the radially inner side. The guide portion 17 is formed by continuously cutting the contact portion 16 of the stabilizer 14 in the circumferential direction to form a step portion, and the guide portion 17 has a contact surface 17a and a wall surface 17 b. The contact surface 17a is a surface substantially parallel to the end surface 16b of the stabilizer 14, and the contact surface 17a is in contact with the skin when the stabilizer 14 is pressed against the skin. The distance between the contact surface 17a and the end surface 16b corresponds to the "guide portion height y" of the fourth embodiment. In addition, the value of the guide portion height y is set so that the skin can be pierced by applying appropriate pressure to the needle tube 2 and the stabilizer 14.

The wall surface 17b is a continuous curved surface substantially perpendicular to the contact surface 17a, and the wall surface 17b faces the same direction as the outer peripheral surface of the contact portion 16. The distance between the wall surface 17b and the outer peripheral surface of the contact portion 16 corresponds to the "guide portion length x" of the fourth embodiment.

Further, similarly to the injection needle assembly 31 of the fourth embodiment, by pressing the stabilizer 14 until the contact surface 17a of the guide portion 17 contacts the skin, the force with which the stabilizer 14 presses the skin can be always maintained at a predetermined value or more. As a result, the needle tip and the blade surface of the needle tube can be reliably positioned on the skin layer portion. Therefore, with the injection needle assembly 41, the same functions and advantages as those of the injection needle assembly 31 of the fourth embodiment can also be achieved.

It is to be understood that the injection needle assembly and the medicament injection device according to the present invention are not limited to the above-described embodiments, and various changes and modifications in materials, configurations, and the like may be made without departing from the constitution of the present invention.

Although the stabilizer 4(14) is fixed to the needle hub 3 according to the first to fifth embodiments of the present invention, the stabilizer according to the present invention may be fixed to, for example, a syringe constituting a medicament injection apparatus. In addition, the stabilizer according to the present invention may also be integrally formed with the needle hub or the syringe.

Claims

1. An injection needle assembly, comprising:

a needle tube having a needle tip capable of piercing a living body;

a needle hub for holding the needle cannula;

a stabilizer formed in a cylindrical shape surrounding a periphery of the needle tube, and having an end surface that comes into contact with a skin of a living body when the living body is punctured with the needle tube; and

a guide portion provided to the stabilizer, the guide portion guiding a pressurizing parameter applied from the needle tube and the stabilizer to a living body by being in contact with a skin when the living body is punctured with the needle tube.

2. The injection needle assembly according to claim 1,

the stabilizer is a skin deformer adapted to form a skin protrusion in a tube bore of the skin deformer by pressing an end face of the stabilizer against skin,

the compression parameter is an insertion distance of the skin deformer into the skin,

the guide portion is a distance identifier adapted to identify the press-in distance.

3. The injection needle assembly according to claim 2, wherein the distance identifier is a stepped portion formed on an outer peripheral surface of the skin deformer.

4. The injection needle assembly according to claim 2, wherein the distance identifier is a flange portion protruding from an outer peripheral surface of the skin deformer.

5. The injection needle assembly of claim 3 or 4, wherein the distance identifier has a contact face parallel to an end face of the skin deformer, the contact face identifying the pressing distance of the skin deformer into the skin by contact with the skin.

6. The injection needle assembly of claim 5, wherein the contact surface of the distance identifier is continuous with the outer circumferential surface of the skin deformer and an identifier length is in a range of 0.5mm to 5.0mm, wherein the identifier length is a length of the contact surface of the distance identifier in a direction perpendicular to the outer circumferential surface of the skin deformer.

7. The injection needle assembly according to claim 6, wherein the tube bore of the skin deformer is formed in a circular shape.

8. The injection needle assembly of claim 7, wherein the diameter of the bore of the skin deformer is in the range of 8mm to 28 mm.

9. The injection needle assembly of claim 8, wherein the diameter of the tube bore of the skin deformer is in the range of 11mm to 14 mm.

10. The injection needle assembly according to claim 9, wherein in the case where the identifier length is set in the range of 3.0mm to 5.0mm, if the height of the skin protrusion is represented by z and the distance between the end face of the skin deformer and the distance identifier is represented by y, then z and y satisfy a relationship defined by the following expression:

Z＝0.1y+0.1。

11. the injection needle assembly according to claim 1, further comprising an adjustment portion arranged around the needle tube, the adjustment portion having a needle-projecting surface from which a needlepoint of the needle tube projects,

the specification of the needle tube is 26G-33G, an

The pressurization parameter is pressure.

12. The injection needle assembly according to claim 11, wherein the pressure is in the range of 0.5N to 20N.

13. The injection needle assembly according to claim 11, wherein the guide portion has a stepped portion formed on and substantially perpendicular to an outer peripheral surface of the stabilizer.

14. The injection needle assembly according to claim 11, wherein the guide portion is a flange portion that protrudes substantially perpendicularly from an outer peripheral surface of the stabilizer.

15. The injection needle assembly of claim 13 or 14, wherein the stabilizer is formed in a cylindrical shape.

16. The injection needle assembly according to claim 15, wherein in the case where the inner diameter of the stabilizer is set in the range of 12mm to 14mm, if a distance between a contact surface of the guide portion and an end surface of the stabilizer, which contact surface and end surface contact the skin, is represented by y, and a guide portion length, which is a length of the guide portion in a substantially vertical direction from the stabilizer, is represented by x, y and x satisfy a relationship defined by the following expression:

1.0Ln(x)+1.2＜y＜3.1Ln(x)+3.2。

17. the injection needle assembly according to claim 15, wherein a distance between a contact surface of the guide portion and an end surface of the stabilizer is set in a range of 0.75mm to 2.6mm when a guide portion length is 0.5mm, which is a length of the guide portion in a substantially vertical direction from the stabilizer, the contact surface and the end surface contacting the skin, with an inner diameter of the stabilizer being set to 11 mm.

18. The injection needle assembly according to claim 11, wherein the needle-projecting surface of the regulating portion is formed such that a distance from a periphery of the needle-projecting surface to a peripheral surface of the needle tube is in a range of 0.3mm to 1.4 mm.

19. The injection needle assembly according to claim 11, wherein a distance from an inner wall of the stabilizer to an outer peripheral surface of the regulating portion is set in a range of 4mm to 15 mm.

20. A medicament injection apparatus, comprising:

a needle tube having a needle tip capable of piercing a living body;

a needle hub for holding the needle cannula;

a syringe connected to the needle hub;