JP7210921B2 - needle-free syringe - Google Patents

Description

TECHNICAL FIELD The present invention relates to a needleless injector for injecting an injection target substance into an injection target region without using an injection needle.

2. Description of the Related Art Needle-free injectors that inject an injection solution into an object without using an injection needle are widely known. For example, Patent Literature 1 discloses a needle-free syringe having a suction cup attached to its distal end. In this technique, a negative pressure is created in the suction cup while the suction cup is pressed against the patient's skin.

Further, Patent Document 2 discloses that an adapter is attached to the tip of an ampoule in an injection device that injects an infusion liquid from an orifice of the ampoule.

U.S. Patent Application Publication No. 2015/0246183 U.S. Pat. No. 6,752,780

A needle-free injector is provided with a nozzle portion formed with an injection port for injecting an injection target substance. In such a needle-free injector, in order to accurately deliver the injection target substance ejected from the injection port to the target site of the injection target region, an appropriate contact state must be formed between the injection target region and the nozzle portion. must. In addition, the contact state between the injection target region and the nozzle part that enables accurate delivery of the injection target substance to the target site of the injection target region in this way may also be referred to as the "desired contact state" hereinafter. be.

However, the contact state between the injection target region and the nozzle section may change due to differences in user's technique and the like. Therefore, it may be difficult to form a desired contact state simply by pressing the nozzle portion against the surface of the injection target region by the user.

Here, according to the needle-free syringe described in Patent Document 1, the patient's skin is sucked into the suction cup by creating a negative pressure inside the suction cup. This results in contact between the patient's skin and the ejection port. With such a needle-free injector, it is necessary to create a negative pressure in the suction cup before the injection is performed, which increases the burden on the user when performing the injection.

SUMMARY OF THE INVENTION An object of the present invention is to provide a needle-free injector capable of suitably forming a desired contact state between an injection target region and a nozzle portion.

The needle-free injector of the present invention includes a nozzle portion and a pressing portion, and the nozzle portion is formed such that the tip surface thereof falls within the expected range. Here, the assumed range is a position range including an assumed position determined based on the width of the predetermined region of the injection target region, and the entire range is between the predetermined end of the housing and the tip surface of the pressing portion. included in the range between Then, when the injection target region is pressed by the pressing portion, the space surrounded by the pressing portion accommodates the injection target region existing in the predetermined region, and the injection target region abuts the tip surface of the nozzle portion. With such a configuration, a desired contact state can be preferably formed between the injection target region and the nozzle portion.

Specifically, the needle-free injector of the present invention is a non-injection device that injects the injection target substance into the injection target region by injecting the injection target substance while pressing the injection target region without using an injection needle. A needle syringe, comprising: a container provided in a housing of the needle-free injector for containing the injection target substance; and a container provided in the housing for injecting the injection target substance contained in the container. A driving portion that generates injection energy, and a nozzle portion that protrudes from a predetermined end that is a predetermined end of the housing on the housing portion side, and the injection energy generated by the driving portion is applied. a nozzle portion formed with an injection port for injecting the injected injection target substance toward the injection target region; a pressing part configured to form a predetermined area surrounded by the tip surface in the injection target area when the tip surface contacts the injection target area. In the needle-free injector of the present invention, the tip surface of the nozzle part belongs to an assumed range, which is a position range including an assumed position where the tip surface is assumed to be located in the axial direction of the housing. wherein the assumed position is determined based on the width of the predetermined area, and the assumed range is a position range defined including a position displaced from the assumed position by a predetermined distance in the axial direction of the housing. and the entire range is included in the range between the predetermined end portion in the axial direction of the housing and the tip surface of the pressing portion, and when the injection target region is pressed by the pressing portion, A space belonging to a range between the predetermined end portion in the axial direction of the housing and a tip surface of the pressing portion and surrounded by the pressing portion accommodates the injection target region existing in the predetermined region; Furthermore, it is configured such that the injection target region abuts on the distal end surface of the nozzle portion.

Here, for example, when the pressing portion is formed in a cylindrical shape, the width of the predetermined region is equal to the inner diameter of the pressing portion. Moreover, if the inner diameter of the pressing portion is not constant, the representative inner diameter of the pressing portion (for example, the maximum value of the inner diameter) may be used as the width of the predetermined region. The width of the predetermined region has a correlation with the swelling height of the injection target region that rises in the space surrounded by the pressing portion when the injection target region is pressed by the pressing portion. Therefore, in the needle-free syringe of the present invention, the assumed position where the tip surface of the nozzle portion is assumed to be located is determined based on the width of the predetermined region. The assumed position determined in this way is included in the range between the predetermined end portion of the housing in the axial direction and the tip surface of the pressing portion (hereinafter sometimes referred to as the "syringe tip range"). Then, when the tip surface of the nozzle portion is provided at the assumed position, the tip surface of the nozzle portion is recessed from the tip surface of the pressing portion in the axial direction of the housing. In this case, in the space belonging to the syringe tip range and surrounded by the pressing portion (hereinafter sometimes referred to as "syringe tip space"), it is easy to secure room for the injection target region to swell, and the syringe tip space. , the injection target region that rises toward the tip surface of the nozzle portion abuts on the tip surface.

It should be noted that the height of the swelling of the injection target region can also change due to a change in the pressing conditions of the pressing portion with respect to the injection target region. Therefore, an assumed range is defined as a position range that includes a position displaced from the assumed position by a predetermined distance in the axial direction of the housing. Here, the predetermined distance is defined according to variations in the height of the protrusion that can occur due to changes in pressing conditions. In other words, the assumed range is the range of assumed positions in consideration of variations in swelling height of the injection target region. The assumed range is also included in the syringe tip range, as is the assumed position.

Further, when the nozzle portion is formed such that the tip surface thereof falls within the above-described assumed range, the situation in which the nozzle portion obstructs the swelling of the injection target region existing in the predetermined region is suppressed as much as possible, and the syringe can be In the tip space, the injection target region naturally swells toward the tip surface of the nozzle part. Then, the injection target area and the tip surface of the nozzle portion are naturally brought into contact with each other. According to this, even if the syringe is tilted in a state where the injection target region is pressed by the pressing part, the injection target region is prevented from forming a gap between the injection target region and the tip surface of the nozzle part and the tip surface of the nozzle portion are brought into contact with each other. That is, a desired contact state is formed between the injection target region and the nozzle portion.

According to the needle-free injector described above, a desired contact state can be suitably formed between the injection target region and the nozzle portion, and the injection target substance can be administered to the target site of the injection target region accurately. It is possible to perform this operation stably and with good reproducibility.

Here, in the needle-free syringe of the present invention, the pressing portion is formed in a cylindrical shape, and the assumed position is between the tip surface of the nozzle portion and the tip surface of the pressing portion in the axial direction of the housing. may be defined as a position where the distance is 1/30 or more and 1/16 or less of the inner diameter of the pressing portion. By doing so, a desired contact state is formed between the injection target region and the nozzle part more preferably, and as a result, the injection target substance can be administered to the target site of the injection target region accurately and stably. Good reproducibility is possible.

The pressing portion may be formed in a cylindrical shape, and may have a tapered shape in which the interval between the inner peripheral surface and the outer peripheral surface thereof gradually decreases toward the distal end surface along the axial direction. . According to this, it becomes easier to stably maintain the pressing state of the injection target region by the pressing portion, thereby stably forming and maintaining a desired contact state between the injection target region and the nozzle portion. can.

Further, the nozzle portion may be formed such that its diameter gradually decreases toward the tip end surface. According to such a configuration, the nozzle part is easily fixed by the injection target area surrounding the peripheral edge of the tip surface, and a desired contact state is easily maintained between the injection target area and the nozzle part.

ADVANTAGE OF THE INVENTION According to this invention, a desired contact state can be suitably formed between an injection object area|region and a nozzle part.

It is a figure showing a schematic structure of a syringe concerning an embodiment of the present invention. FIG. 10 is a diagram for explaining a state of contact between the injection target region and the tip surface of the nozzle portion when the injection solution is injected into the injection target region of the object. FIG. 4 is a first diagram for explaining the relationship between the inner diameter of the rim and the height of the swelling of the injection target region. FIG. 11 is a second diagram for explaining the relationship between the inner diameter of the rim and the height of the injection target area. FIG. 11 is a third diagram for explaining the relationship between the inner diameter of the rim and the height of the injection target area. 4 is a graph showing the correlation between the inner diameter of the rim and the elevation height of the injection target area. It is a figure for demonstrating an assumption range. FIG. 10 is a view showing a state of contact between the skin of a living body and the distal end surface of the nozzle portion when the skin of the living body is pressed by the rim, and showing a case where the syringe is tilted. It is a figure showing a schematic structure of a syringe concerning modification 1 of an embodiment of the present invention. FIG. 10 is a diagram showing a state of contact between the skin of the living body and the tip surface of the nozzle section when the skin of the living body is pressed by the rim in Modification 1; It is a figure showing a schematic structure of a syringe concerning modification 2 of an embodiment of the present invention. FIG. 10 is a diagram showing a contact state between the skin of a living body and the tip surface of the nozzle portion when the skin of the living body is pressed by a rim in Modification 2; 4 is a diagram showing the range of values of A and the relationship between the rim inner diameter d1 and the distance L at that time in Example 1. FIG.

Hereinafter, a needle-free syringe 1 (hereinafter simply referred to as "syringe 1") will be described as an example of a syringe according to an embodiment of the present invention with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

<Embodiment>
FIG. 1(a) is a cross-sectional view of the syringe 1, and FIGS. 1(b) and 1(c) are views of the syringe 1 viewed from the tip side. In the following description of the present application, the injection target substance that is injected into the injection target area of the object by the syringe 1 is collectively referred to as "injection solution". However, it is not intended to limit the content or form of the substance to be injected. In the injection target substance, the components to be delivered to the skin structure may or may not be dissolved. If so, its specific form is irrelevant, and various forms such as liquid, gel, and powder can be adopted.

Here, the syringe 1 has a housing 2 including a distal housing 3 , a proximal housing 4 and a syringe portion 5 , with the syringe portion 5 between the distal housing 3 and the proximal housing 4 . are placed. The housing 2 is constructed by fixing these with screws and integrating them. However, the distal housing 3, the proximal housing 4, and the syringe part 5 can be connected by a known method other than screws. A hole 40, which is an inner space extending in the axial direction, is formed inside the base end housing 4. As shown in FIG.

The syringe part 5 has therein a storage chamber (storage part) 50 that stores the injection solution ML. The syringe part 5 is screwed and attached to the proximal housing 4, and in the attached state, the hole 40 in the proximal housing 4 and the storage chamber 50 in the syringe part 5 are a continuous space. becomes. In the attached state, the injection solution ML is liquid-tightly stored in the storage chamber 50 by the plunger 7, and the plunger 7 is exposed to the hole 40 side. Here, the plunger 7 is slidably arranged in the housing chamber 50, and pressurizes the injection solution ML by sliding, and the injection solution is ejected from the injection port. The plunger 7 is made of a rubber member whose surface is thinly coated with silicon oil so that it can slide smoothly in the housing chamber 50 . In order to improve the slidability of the plunger 7, for example, the surface of the plunger 7 may be processed with fluorine.

A metal piston 6 is arranged in a hole 40 in the base end housing 4 , and the piston 6 is slidably held in the hole 40 . The piston 6 is formed generally in the shape of a shaft extending along the axial direction of the bore 40, and has a first end 6a in contact with the plunger 7 disposed in the syringe portion 5, and a side opposite to the first end 6a. and a second end portion 6b that is provided at the end portion 6b and defines a combustion chamber 41, which will be described later. Further, around the piston 6 on the side of the second end 6b, combustion products due to combustion of the ignition charge, which will be described later, are sealed in the combustion chamber 41, and the piston 6 can smoothly slide in the hole 40. An O-ring 6c configured to be is arranged.

Furthermore, an initiator 20 is arranged on the side of the base-end housing 4 opposite to the side where the syringe portion 5 is attached. As shown in FIG. 1A, the initiator 20 is provided at the proximal end of the housing 2 . Then, the combustion chamber 41 formed at one end of the hole 40 is closed by the initiator 20 . Here, the space defined by the initiator 20 in the hole 40 and the second end 6b of the piston 6 becomes the combustion chamber 41 . Then, when a voltage is applied to the initiator 20, the ignition charge of the initiator 20 is burned. Then, combustion products generated by combustion of the ignition charge flow into the combustion chamber 41, and the pressure in the combustion chamber 41 rises. Thus, injection energy for injecting the injection solution ML stored in the storage chamber 50 is generated. Note that the initiator 20 serves as a drive unit that generates this injection energy.

Here, the igniter used in the syringe 1 is preferably a gunpowder containing zirconium and potassium perchlorate (ZPP), a gunpowder containing titanium hydride and potassium perchlorate (THPP), or titanium and potassium perchlorate. explosives containing aluminum and potassium perchlorate (APP), explosives containing aluminum and bismuth oxide (ABO), explosives containing aluminum and molybdenum oxide (AMO), explosives containing aluminum and copper oxide (ACO ), explosives containing aluminum and iron oxides (AFO), or combinations of several of these explosives. These explosives generate high-temperature, high-pressure plasma when they burn immediately after ignition, but when they reach room temperature and condensed combustible organisms, they do not contain gaseous components, so the generated pressure drops sharply. Explosives other than these may be used as the igniter.

In addition, although nothing is arranged in the combustion chamber 41 shown in FIG. may If a gas generating agent is arranged in the combustion chamber 41, one example thereof is a single-base smokeless gunpowder composed of 98% by mass of nitrocellulose, 0.8% by mass of diphenylamine, and 1.2% by mass of potassium sulfate. It is also possible to use various gas generating agents used in air bag gas generators and seat belt pretensioner gas generators. When the gas generating agent is used in combination, unlike the case where the ignition agent is used alone, the predetermined gas generated during combustion contains gaseous components even at room temperature, so the rate of decrease in generated pressure is small. Furthermore, the combustion completion time of the gas generating agent is much longer than that of the ignition charge, but the size, size, shape, especially surface shape of the gas generating agent when placed in the combustion chamber 41 By adjusting , it is possible to change the combustion completion time of the gas generating agent. By adjusting the amount, shape, and arrangement of the gas generating agent in this manner, the generated pressure within the combustion chamber 41 can be adjusted appropriately.

In the syringe 1 configured as described above, the tip end housing 3 is further screwed onto the syringe portion 5 and attached thereto. The tip end housing 3 is attached to the syringe portion 5 with a gasket 3a interposed therebetween. A nozzle portion 8 and a rim 9 (pressing portion) are integrally formed with the tip-side housing 3 . Here, the nozzle portion 8 and the rim 9 are provided so as to protrude from a predetermined end portion 2a, which is a predetermined end portion on the tip side (accommodation chamber 50 side) of the housing 2 . In addition, the nozzle portion 8 and the rim 9 may be provided as separate parts from the distal housing 3 . Also, the directions of projection of the nozzle portion 8 and the rim 9 are parallel to the axial direction of the housing 2, but they do not necessarily have to be parallel to the axis, and may be slightly inclined.

Here, the nozzle portion 8 is formed coaxially with the central axis of the syringe 1 and has a smaller diameter than the tip side housing 3 on the side of the syringe portion 5 . An injection port 8b is formed in the tip surface 8a of the nozzle portion 8. As shown in FIG. The injection solution ML pressurized by the plunger 7 flows through the flow path formed in the distal housing 3 and is ejected from the ejection port 8b. More specifically, when the ignition charge in the initiator 20 burns and the pressure in the combustion chamber 41 rises, the piston 6 slides toward the tip of the injector 1 . As the piston 6 slides, the plunger 7 presses the injection solution ML stored in the storage chamber 50 . As a result, the injection solution ML flows through the flow path formed in the distal housing 3 and is ejected from the injection port 8b toward the injection target region.

A plurality of ejection ports 8b may be formed in the tip surface 8a of the nozzle portion 8, or one ejection port 8b may be formed. When a plurality of injection ports are formed, a flow path corresponding to each injection port is formed in the nozzle part 8 so that the injection liquid ML is sent to each injection port as evenly as possible. Furthermore, when a plurality of ejection ports are formed, it is preferable that the ejection ports are arranged at regular intervals around the central axis of the syringe 1, as shown in FIG. 1(c).

A rim 9 is formed around the nozzle portion 8 in the distal housing 3 . The rim 9 is formed in a cylindrical shape protruding from the predetermined end portion 2a, and as shown in FIG. 1(b), its inner diameter is represented as d1. Also, a space 10 is formed inside the rim 9 . The space 10 belongs to the range between the predetermined end 2a of the housing 2 in the axial direction and the tip surface 9a of the rim 9 and is a space surrounded by the rim 9, and the nozzle portion 8 is arranged in the space 10. It is In this embodiment, the interval (width) between the inner peripheral surface and the outer peripheral surface of the rim 9 does not change along the axial direction and is constant. Also, in this embodiment, the rim 9 has a continuous annular shape in the circumferential direction, but it may be formed in a plurality of independent circular arc shapes as long as the effects of the present invention described later can be obtained. However, even in that case, the arc length is set to be longer than the distance between adjacent arcs.

Here, in the syringe 1 according to the present invention, the tip surface 8a of the nozzle portion 8 is formed at a position between the predetermined end portion 2a of the housing 2 in the axial direction and the tip surface 9a of the rim 9 . In this embodiment, the distance between the tip surface 8a of the nozzle portion 8 and the tip surface 9a of the rim 9 in the axial direction of the housing 2 is the distance L. As shown in FIG. In the following description, the position of the distance L from the distal end surface 9a of the rim 9 to the base end side of the syringe 1 in the axial direction of the housing 2 is referred to as the "assumed position" of the distal end surface 8a of the nozzle portion 8. The details of this assumed position will be described later.

In the syringe 1 according to the present invention, the tip surface 8a of the nozzle portion 8 is formed in this way, and the injection target region is pressed by the rim 9 when the injection solution ML is injected into the injection target region of the object. As a result, a portion of the injection target area will enter the space 10 at this time. In other words, the space 10 will accommodate part of the injection target area. Note that the rim 9 serves as a pressing portion that presses the injection target region. This will be explained in detail below.

FIG. 2 is a diagram for explaining the state of contact between the injection target region and the tip surface 8a of the nozzle portion 8 when the injection solution ML is injected into the injection target region of the object. In the present invention, the injection solution ML is injected while the injection target region is pressed by the rim 9 . Here, FIG. 2(a) shows a state in which the surface of the injection target region and the tip surface 9a of the rim 9 are in contact, and FIG. 2(b) shows the state shown in FIG. 2(a). , the injection target region is further pressed by the rim 9 from . Further, FIG. 2(c) shows a state in which the initiator 20 is activated in the state shown in FIG. 2(b) and injection of the injection liquid ML is completed.

Here, the rim 9 is configured to form a predetermined area surrounded by the tip surface 9a in the injection target area when the tip surface 9a contacts the injection target area. In the example shown in FIG. 2(a), which shows the state where the tip surface 9a of the rim 9 is in contact with the injection target area, this predetermined area is represented by area A1. The state of FIG. 2(a) is a state in which the syringe 1 is not pressed against the injection target region, and at this time, the tip surface 8a of the nozzle portion 8 is not in contact with the injection target region. In this embodiment, the width of the predetermined area represented by the area A1 is equal to the inner diameter d1 of the rim 9. As shown in FIG. However, there is no intention to limit it to this, and if the inner diameter of the rim 9 is not constant (for example, when the inner peripheral edge in the cross-sectional shape of the rim 9 is elliptical), the width of the predetermined area should be the representative of the rim 9 An inner diameter (eg, maximum inner diameter) may be used.

Then, when the injection target area is pressed by the rim 9, as shown in FIG. 2(b),
The portion of the injection target area that contacts the rim 9 is pushed down, and the injection target area existing in the area A1 enters the space 10 . Then, the injection target area and the tip surface 8a of the nozzle part 8 are brought into contact with each other. In the state shown in FIG. 2(b), it is assumed that a desired contact state, which will be described later, is formed between the injection target region and the nozzle portion 8. As shown in FIG.

When a voltage is applied to the initiator 20 in the state shown in FIG. 2(b), combustion products produced by combustion of the ignition charge flow into the combustion chamber 41, and the pressure inside the combustion chamber 41 rises. Then, the injection solution ML is pressed by the plunger 7, and the injection solution ML is ejected from the injection port 8b toward the injection target region. As a result, the syringe 1 reaches the state shown by FIG. 2(c).

As described above, in the syringe 1, when the injection liquid ML is injected into the injection target region of the object, the injection liquid ML is injected from the injection port 8b while the injection target region and the tip surface 8a of the nozzle portion 8 are in contact with each other. is injected. However, the contact state between the injection target region and the nozzle portion 8 may change due to differences in user's technique or the like. If an appropriate contact state as shown in FIG. 2 is not formed between the injection target region and the nozzle part 8, there is a risk that the injection solution ML cannot be accurately delivered to the target site of the injection target region. be. Therefore, there has been a demand for a needle-free injector that can form an appropriate contact state between the injection target region and the nozzle portion 8 as shown in FIG.

Therefore, in the syringe 1 according to the present invention, the assumed position of the tip surface 8a of the nozzle portion 8 is determined based on the width of the predetermined region described above. This will be described with reference to FIGS. 3A to 3C and 4. FIG.

3A to 3C show the inner diameter of the rim 9 and the elevation height of the injection target region existing in a predetermined region when the injection target region is pressed by the rim 9 (hereinafter, simply referred to as "rising height"). , and is a diagram for explaining the relationship between . 3A shows the height of the rise when the inner diameter of the rim 9 is d1, FIG. 3B shows the height of the rise when the inner diameter of the rim 9 is d2, which is smaller than d1, and FIG. 4 shows the height of the bulge when d3 is greater than . 3A to 3C, it is assumed that the nozzle portion 8 is not arranged inside the rim 9 in order to explain the height of the swelling.

As shown in FIG. 3A, when the inner diameter of the rim 9 is d1, the bulging height is h1. Here, the height of the swelling is defined as the maximum height of the swelling of the injection target area existing in a predetermined area from the tip surface 9a of the rim 9. As shown in FIG. Further, when the pressing force is the same, the depth of bite of the tip surface 9a of the rim 9 into the injection target area surface is the same at h0. Then, as shown in FIG. 3B, when the inner diameter of the rim 9 is d2, which is smaller than d1, the swelling height is h2, which is smaller than h1. Further, as shown in FIG. 3C, when the inner diameter of the rim 9 is d3, which is larger than d1, the swelling height is h3, which is larger than h1.

The relationship between the inner diameter d of the rim 9 and the height h of the injection target region is represented by the correlation graph shown in FIG. As shown in FIG. 4, when the inner diameter d of the rim 9 is equal to or greater than a predetermined lower limit value dmin and equal to or less than a predetermined upper limit value dmax, the swelling height h is expressed by the following equation 1 as a function of the inner diameter d of the rim 9. be.
h=d×1/A Formula 1
Note that A in Equation 1 above is a constant greater than 1, and is determined according to the pressing force of the rim 9, the elasticity of the injection target region, the surface hardness, and the like. Further, the predetermined lower limit value dmin is, for example, 8 mm, and the predetermined upper limit value dmax is, for example, 15 mm. However, if the inner diameter d of the rim 9 is extremely small, it is considered that the height h of the bulge is substantially close to 0, and the inner diameter d of the rim 9 is set to a value larger than the outer diameter of the nozzle portion 8. be. On the other hand, if the inner diameter d of the rim 9 increases, it is thought that there will be a portion where the linear relationship shown in FIG.

Here, the inventors of the present invention have found that the injection target region, which rises as shown in FIGS. Therefore, the injection solution ML can be delivered to the target site of the injection target region accurately. Then, in view of the correlation shown in Equation 1 above, the distance L, which represents the assumed position of the tip surface 8a of the nozzle portion 8, is expressed by Equation 2 below based on the width of the predetermined region, that is, the inner diameter d1 of the rim 9. be done.
L=d1×1/A Formula 2

Moreover, the height of the swelling described above can also change as the pressing conditions change. Therefore, in this embodiment, the distance L can be included in the range represented by the following formula 3 in consideration of the variation in the height of the swelling.
d1×1/A−b≦L≦d1×1/A+b Formula 3
Here, b is a constant for taking into consideration variations in the height of swelling that may occur due to changes in pressing conditions, etc., and will be described with reference to FIG. 5 below. Further, the range represented by Equation 3 above is hereinafter referred to as the "assumed range".

FIG. 5 is a diagram for explaining the assumed range. As shown in FIG. 5, in the present embodiment, the tip surface 8a of the nozzle portion 8 is provided at a position where the distance from the tip surface 9a of the rim 9 is represented by Equation 2 above. However, the position of the tip surface 8a of the nozzle portion 8 is not limited to this, and the nozzle portion 8 may be formed so that the tip surface 8a belongs to the assumed range shown in FIG. Here, the assumed range is displaced by a predetermined distance (b in FIG. 5) in the axial direction of the housing 2 from the assumed position (in FIG. 5, the distance from the tip surface 9a of the rim 9 is indicated by L). A position range defined including the position. Then, as shown in FIG. 5 , the entire assumed range is included in the range between the predetermined end 2 a of the housing 2 in the axial direction and the tip end surface 9 a of the rim 9 .

If the nozzle portion 8 is formed such that the tip end surface 8a thereof falls within the assumed range described above, the nozzle portion 8 may impede the swelling of the injection target region existing in the predetermined region as much as possible. The injection target region and the tip surface 8a of the nozzle portion 8 are naturally brought into contact with each other while being restrained to a certain degree. This is because the space 10 has a space that allows the injection target region existing in the predetermined region to naturally swell.

In view of the above, according to the syringe 1 according to the present invention, when injecting the injection solution ML into the injection target region of the object, it is possible to accurately deliver the injection solution ML to the target site of the injection target region. Injection can be performed in a state in which the contact state between the injection target region and the nozzle portion 8 (hereinafter sometimes referred to as "desired contact state") is appropriately formed. For example, even if the injection target region is pressed by the rim 9 and the syringe 1 is tilted or the like, a desired contact state between the injection target region and the nozzle part 8 can be formed with good reproducibility. can be done. This will be described with reference to FIG.

FIG. 6 shows the state of contact between the skin of the living body and the distal end face 8a of the nozzle portion 8 when the skin of the living body is pressed by the rim 9. As shown in FIG. In the example shown in FIG. 6, it is assumed that the syringe 1 is tilted when the skin is pressed by the rim 9 . In general, when a needle-free injector in which injection is performed by bringing the tip surface of the nozzle into contact with the skin is tilted, a gap is likely to occur between the skin and the tip surface of the nozzle, resulting in a gap between the skin and the tip surface of the nozzle. It becomes difficult to form a desired contact state between them.

On the other hand, in the syringe 1 according to the present invention, even if the syringe 1 is tilted when the skin is pressed by the rim 9, as shown in FIG. Since it naturally rises toward the tip surface 8a, the skin and the tip surface 8a are brought into contact with each other without creating a gap between the skin and the tip surface 8a. That is, a desired contact state is formed between the injection target region and the nozzle portion 8 . At this time, the deformation of the injection target region in the space 10 is dominated by the geometric shapes of the rim 9 and the nozzle portion 8. 8, a desired contact state can be formed with good reproducibility.

According to the syringe 1 described above, a desired contact state can be preferably formed between the injection target region and the nozzle portion 8 . As a result, the injection solution ML can be administered accurately, stably, and reproducibly to the target site of the injection target region.

<Modification 1 of Embodiment>
Next, Modification 1 of the above-described embodiment will be described with reference to FIGS. 7 and 8. FIG. In addition, in this modification, the detailed description is abbreviate|omitted about the substantially same structure as embodiment mentioned above. FIG. 7(a) is a cross-sectional view of the syringe 1 according to this modification, and FIGS. 7(b) and 7(c) are views of the syringe 1 according to this modification as viewed from the tip side.

As shown in FIG. 7(a), in the syringe 1 according to this modified example, the rim 9 has a tapered portion 9b. Specifically, a tapered portion 9b is formed on the inner peripheral surface of the cylindrical rim 9, and the tapered portion 9b causes the gap between the inner peripheral surface and the outer peripheral surface of the rim 9 to move toward the tip surface 9a along the axial direction. is gradually reduced according to A tapered portion may be formed on the outer peripheral surface of the cylindrical rim 9 so that the distance between the inner peripheral surface and the outer peripheral surface of the rim 9 gradually decreases toward the tip surface 9a along the axial direction. good.

Further, in this modification, as shown in FIG. 7B, the inner diameter of the rim 9 at the tip surface 9a is represented as d2. At this time, the distance L' between the tip surface 8a of the nozzle portion 8 and the tip surface 9a of the rim 9 in the axial direction of the housing 2 is determined by the following formula based on the width of the predetermined region, that is, the inner diameter d2 at the tip surface 9a of the rim 9. 4.
L′=d2×1/A Formula 4
With such a syringe 1 as well, a desired contact state can be suitably formed and maintained between the injection target region and the nozzle portion 8 . This will be described with reference to FIG.

The example shown in FIG. 8 shows the state of contact between the skin of the living body and the tip surface 8a of the nozzle portion 8 when the skin of the living body is pressed by the rim 9, as in FIG. According to the syringe 1 according to this modified example, as shown in FIG. 8, the rim 9 digs into the skin relatively deeply. This is because when the pressing force is the same, the thinner the tip of the rim 9 (the smaller the area of the tip surface 9a of the rim 9), the more concentrated the load applied to the skin surface by the tip surface 9a of the rim 9. be. When the skin is pressed in this way, the skin naturally swells toward the tip surface 8a of the nozzle portion 8 in the space 10 as in the above-described embodiment, and the skin and the nozzle portion 8 form a gap between the skin and the nozzle portion 8. A desired contact condition is formed.

And according to such a syringe 1, a desired contact state can be stably formed and maintained between the injection target region and the nozzle portion 8. As shown in FIG. This is because the rim 9 digs into the injection target region relatively deeply, so that the pressing state of the injection target region by the rim 9 can be stably maintained. According to this, even if the syringe 1 is tilted or the like in the process of performing an injection operation, for example, the injection target region raised as described above in the space 10 can be satisfactorily fixed in its deformation mode. can be done.

In other words, a desired contact state is preferably formed and maintained between the injection target region and the nozzle part 8, thereby accurately and stably reproducing the administration of the injection solution ML to the target site of the injection target region. It is possible to do well.

<Modification 2 of Embodiment>
Next, Modification 2 of the above embodiment will be described with reference to FIGS. 9 and 10. FIG. In addition, in this modification, the detailed description is abbreviate|omitted about the substantially same structure as embodiment mentioned above. Fig. 9(a) is a cross-sectional view of the syringe 1 according to this modification, and Figs. 9(b) and 9(c) are views of the syringe 1 according to this modification as viewed from the distal end side.

In the syringe 1 according to this modification, the nozzle portion 8 is formed such that the diameter thereof gradually decreases toward the tip surface 8a along the axial direction. With such a syringe 1 as well, a desired contact state can be preferably formed and maintained between the injection target region and the nozzle portion 8 . This will be described with reference to FIG.

Similar to FIG. 6, the example shown in FIG. 10 shows the state of contact between the skin of the living body and the tip surface 8a of the nozzle portion 8 when the skin of the living body is pressed by the rim 9. FIG. According to the syringe 1 according to the present modification, the nozzle part 8 is easily fixed by the injection target region surrounding the periphery of the tip surface 8a, and the desired contact state is maintained between the injection target region and the nozzle part 8. easier to be

In other words, a desired contact state is preferably formed and maintained between the injection target region and the nozzle part 8, thereby accurately and stably reproducing the administration of the injection solution ML to the target site of the injection target region. It is possible to do well.

Here, the experimental conditions and the experimental results of the administration experiment to pig living bodies when using the syringe 1 according to the present invention are shown below. In this example, the storage chamber 50 of the syringe 1 was filled with 100 μL of Indian ink, and the syringe 1 was operated with the rim 9 of the syringe 1 pressing against the abdomen of the pig. At this time, it was visually confirmed that the tip surface 8a of the nozzle portion 8 was in contact with the skin surface of the pig. After the injection port 8b of the nozzle portion 8 ejected the entire amount of India ink by operating the syringe 1, the syringe 1 was removed from the skin surface and the affected area surface was observed. In addition, the skin of the affected area was excised and the cross section of the affected area was observed.

<Experimental conditions>
(Regarding pressing force)
The pressing force of the rim 9 against the abdominal skin of the pig was set to 4 to 6N.
(Regarding distance L)
The distance L representing the assumed position of the tip surface 8a of the nozzle portion 8 is a value calculated when the range of A in the above equation 2 is 16-30. Here, FIG. 11 shows the range of values of A in this embodiment and the relationship between the inner diameter d1 of the rim 9 and the distance L at that time. Then, the shaded range in FIG. 11 is the value range of the distance L in this embodiment. In this example, the affected part surface and the affected part cross section were observed when the distance L was 0.5 mm and the value of A was 16, 22, and 30. FIG. When A=16 and L=0.5 mm, the inner diameter d1 of the rim 9 is 8 mm. Further, when A=22 and L=0.5 mm, d1=11 mm, and when A=30 and L=0.5 mm, d1=15 mm.

<Experimental results>
Experimental results are shown in Table 1 below. In addition, "leakage" in the experimental results indicates the presence or absence of an event in which ink discharged from the syringe 1 leaks out of the skin without being administered into the skin of the pig.
The presence or absence of fluid leakage is determined by observing the surface of the affected area. Further, the "administration depth" represents the site where India ink ejected from the syringe 1 reaches in the pig's body, and the administration depth is determined by observing the cross section of the affected area.

(When A=16)
Observation of the surface of the affected area confirmed that there was no liquid leakage. In other words, the entire amount of the ink discharged from the syringe 1 was injected into the skin of the pig. In addition, it was confirmed by observation of the cross section of the affected area that India ink is distributed from the intradermis to the subcutaneous area in the body of the pig.
(When A=22)
As in the case of A=16, it was confirmed that there was no liquid leakage and ink was distributed from the inside to the subcutaneous area.
(When A=30)
As in the case of A=16, it was confirmed that there was no liquid leakage and ink was distributed from the inside to the subcutaneous area.

From the above results, it can be recognized that the tip surface 8a of the nozzle part 8 is in an appropriate contact state with the skin surface of the pig.

<Other embodiments>
According to the syringe 1 according to the present invention, for example, in the field of regenerative medicine for humans, as shown in Japanese Patent Application Laid-Open No. 2008-206477, a person skilled in the art can appropriately determine according to the site to be transplanted and the purpose of recellularization. endothelial cells, endothelial progenitor cells, bone marrow cells, preosteoblasts, chondrocytes, fibroblasts, skin cells, muscle cells, liver cells, kidney cells, intestinal cells, stem cells, and other regenerative medicine fields It is possible to inject with the syringe 1 any cell considered in . More specifically, the liquid containing the cells (cell suspension) is stored in the storage chamber 50, and pressurized against it to inject and implant predetermined cells into the site to be transplanted.

Furthermore, the syringe 1 according to the present invention can also be used for delivery of DNA and the like as described in Japanese Patent Publication No. 2007-525192. In this case, the use of the syringe 1 according to the present invention is more preferable than the case of delivery using a needle, since the effects on cells, scaffolding tissue, scaffolds, etc. can be suppressed.

Furthermore, the syringe 1 according to the present invention is preferably used for delivery of various genes, tumor suppressor cells, lipid envelopes, etc., and administration of antigen genes to enhance immunity against pathogens. In addition, in the field of treatment of various diseases (fields described in Japanese Patent Publication No. 2008-508881, Japanese Patent Publication No. 2010-503616, etc.), immunomedicine fields (fields described in Japanese Patent Publication No. 2005-523679, etc.), etc. , the syringe 1 can be used, and its possible fields of use are not intentionally limited.

Reference Signs List 1 Syringe 2 Housing 3 Distal housing 4 Base housing 5 Syringe part 6 Piston 7 Plunger 8 Nozzle portion 8a Front end surface 8b Ejection port 9 Rim 9a Front end surface 10 Space 20 Initiator 50 Accommodating chamber

Claims (4)

A needle-free injector that injects an injection target substance into an injection target region by injecting the injection target substance while pressing the injection target region without using an injection needle,
a container for containing the substance to be injected, provided in the housing of the needle-free injector;
a driving unit provided in the housing for generating injection energy for injecting the injection target substance contained in the containing unit;
a nozzle portion protruding from a predetermined end portion of the housing on the housing portion side, wherein the injection target substance to which injection energy generated by the driving portion is applied is injected; a nozzle section formed with an injection port for injecting toward a target area;
A pressing portion provided so as to surround the nozzle portion and protruding from the predetermined end portion, wherein when the tip surface thereof contacts the injection target region, a predetermined pressure portion surrounded by the tip surface in the injection target region a pressing portion configured to form a region;
with
the tip end face of the nozzle part is formed so as to belong to an assumed range, which is a positional range including an assumed position where the tip end face is assumed to be located in the axial direction of the housing;
the tip surface of the nozzle portion is formed at a position between the predetermined end portion and the tip surface of the pressing portion in the axial direction of the housing and at a position separated from the tip surface of the pressing portion;
The assumed position is determined based on the width of the predetermined area,
The assumed range is a position range defined including a position displaced from the assumed position in the axial direction of the housing by a predetermined distance, and the entire range is located between the predetermined end portion in the axial direction of the housing. included in the range between the tip surface of the pressing portion,
When the injection target region is pressed by the pressing portion, the injection target region swells toward the tip surface of the nozzle portion, so that the predetermined end portion in the axial direction of the housing and the tip surface of the pressing portion The space belonging to the range between and surrounded by the pressing portion and the predetermined end accommodates the injection target region existing in the predetermined region, and the injection target region in a further raised state is the nozzle Configured to abut on the tip surface of the part,
needleless syringe. The pressing portion is formed in a cylindrical shape,
In the assumed position, the distance between the tip surface of the nozzle portion and the tip surface of the pressing portion in the axial direction of the housing is 1/30 or more and 1/16 or less of the inner diameter of the pressing portion. defined as a position,
The needle-free injector according to claim 1. The pressing portion is formed in a cylindrical shape, and has a tapered shape in which the distance between the inner peripheral surface and the outer peripheral surface thereof gradually decreases toward the distal end surface along the axial direction.
The needleless injector according to claim 1 or 2. The nozzle part is formed such that its diameter gradually decreases toward the tip surface,
The needleless injector according to any one of claims 1 to 3.

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