JP2000126293A - Needleless injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the injection time of a needleless injector even when the amount of a medicinal liquid to be injected is large and to eliminate a pain at the time of injection. SOLUTION: Plural fine injection holes 2a to 2c are provided at the tip curved face part of the nozzle 2 of the needleless injector. Then, at the time of injecting the medicinal liquid taken into a medicinal liquid room 2d in the nozzle 2, the medicinal liquid is injected vertically with respect to the skin surface of an injecting site by the same pressure from the respective holes 2a to 2c, thereby injection can be executed without a pain within a short injecting time without causing any failure of injection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needleless syringe for performing a subcutaneous injection by jetting a predetermined amount of a chemical solution inhaled from an injection hole of a nozzle.

[0002]

2. Description of the Related Art A needleless syringe is a syringe that injects a drug solution into a patient's subcutaneous skin by injecting a predetermined amount of a drug solution from a nozzle orifice of a nozzle at the tip and jetting the drug solution again from the nozzle orifice. In other words, since injection with a needleless syringe is a needleless injection that does not use a syringe needle during subcutaneous injection,
It has advantages such as no pain, no injection marks, and no injection errors. For example, it is also used when a diabetic patient himself / herself injects insulin on a daily basis.

Conventionally, such a needleless syringe has a nozzle 10 as shown in FIG. Piston 1 having a sealing function in nozzle 10
By driving the nozzle 1 back and forth, suction and injection of the chemical solution are performed through the injection holes 10a. The injection hole 10
a is provided on the center axis of the nozzle 10 and has a relatively large diameter so that the injection is completed instantaneously while maintaining a sufficient injection pressure even when the injection amount is large.
Finished to about 16mm. Incidentally, in the case of insulin, it is possible to inject an injection amount of 2 to 50 units.

[0004]

The conventional needleless syringe is constructed as described above. However, if the diameter of the injection hole exceeds a certain value, pain is caused at the time of injection. It has been found to be approximately proportional to size. In addition, if the diameter of the injection hole is reduced, there is no pain at the time of injection, but there is a problem that injection time is prolonged due to a small amount of the liquid medicine injected from the injection hole, and the injection may fail at the injection site due to the movement of the syringe at the injection site. Was.

The present invention has been made in view of such circumstances, and provides a needleless syringe which is free from pain at the time of injection, has a short injection time, and has no injection failure even when the injection amount is large. With the goal.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a needleless syringe for subcutaneously injecting a predetermined amount of a chemical solution inhaled from an injection hole of a nozzle at a distal end by jetting the liquid from the injection hole. , A plurality of injection holes are provided at the tip of the nozzle.

[0007] The needleless syringe of the present invention is configured as described above, and can be injected by injecting a drug solution vertically from a plurality of narrow injection holes to an injection site, thereby reducing pain and injection failure at the time of injection. Can be eliminated.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to examples. FIG. 1 is a cross-sectional view showing an embodiment of a needleless syringe using the nozzle of the present invention, FIG. 2 is a cross-sectional view showing the structure of the nozzle of the present invention, and FIG. FIG.

As shown in FIG. 1, the needleless syringe 1 has a front cylinder 4 and a rear cylinder 5 each having an open end face.
Nozzle having a cylindrical body 6 made of metal or hard resin and screwed with a threaded portion 43 at the tip end thereof, having injection holes 2a, 2b, 2c at the tip and a piston 21 inside. 2, a rod 3 in the hollow portion of the cylindrical body 6 and connected to the piston 21 movably in the axial direction, and a driving mechanism therefor.

The piston 21 has an O-ring 21b for sealing a chemical solution wound around a cone 21a, and a T-shaped connecting portion 21c located behind the O-ring 21b is fitted into the long hole 3a of the rod 3 so as to be attached to the rod 3. Connected. Further, the rod 3 is integrally connected with a flange ring 31 at a length of about 1/4 from the front end thereof, and is provided with a latch hole 35 on the circumference of the rear part and a recess 36 at the rear end part. ing. A guide pipe 32 with a flange 33 is fitted in the axial direction at the rear portion of the rod 3, and a compression spring 34 is disposed between the flange ring 31 and the flange 33 through the rod 3, whereby the rod 3 is A biasing force is provided in the forward direction.

On the other hand, the projection 51 on the circumference in the rear cylinder 5
A fixing ring 52 is fixedly provided at the rear, and a latch ball 53 is fitted into a plurality of small holes 54 provided on the rear circumference. A slide ring 57 is inserted behind the fixing ring 52 so as to be movable in the axial direction, and a latch release button 56 is fitted to the rear end of the slide ring 57 so as to be movable in the axial direction. A movable small piece 58 is fitted to the rear end of the fixed ring 52 so as to be movable in the axial direction. A compression spring 55 is interposed between the movable small piece 58 and the slide ring 57, and the slide ring 57 is constantly urged in the retreating direction by the compression spring 55.

The nozzle 2 has a plurality of injection holes 2a, 2b,
2c, and FIG. 2 shows a cross-sectional view thereof. The distal end has a spherical shape with a radius R having a center point O and is provided with injection holes 2a, 2b, and 2c perpendicular to the spherical surface so as to stably adhere to the injection site. The diameter of these injection holes 2a, 2b, 2c is about 0.08 to 0.12 mm, and the cross-sectional area is reduced from one fourth to one half of the conventional one. Since the injection holes 2a, 2b and 2c are formed perpendicularly to a smooth curved surface such as a spherical surface, the liquid medicine can be injected perpendicularly to the skin surface of the injection site, and the injection amount is large. However, the plurality of injection holes 2a, 2
By using b and 2c, the pain at the time of injection is eliminated,
Injection time can be reduced.

Using the needleless syringe 1 to take in and inject a drug solution is performed in the following manner. As shown in FIG. 3, a case 8a in which an elastic member 9b such as silicone rubber deforming into a concave curved surface 9a in close contact with the tip convex curved surface of the nozzle 2 and a suction needle 9 are integrally fixed, and a case screwed thereto. After inserting the drug solution vial 7 into the inhalation needle 9 and storing it in the vial adapter 8 consisting of the lower portion 8b, the vial adapter 8 is inserted into the cylindrical recess of the nozzle 2 of the needleless syringe 1 and rotated, thereby rotating the needle. The vial adapter 8 is fixed to the syringeless device 1. A suction hole is passed through the elastic member 9b of the suction needle 9 only at a position where it comes into contact with the ejection hole 2a of the nozzle 2.

When the rear cylinder 5 of the needleless syringe 1 after the injection shown in FIG.
While the compression ring 4 is compressed, the fixed ring 52 advances, and the movable small piece 58 is inserted into the recess 36 and stops moving. However, the fixed ring 52 advances, the latch ball 53 enters the latch hole 35, and the slide ring 57 is moved by the compression spring 55. Is retracted, and the latch release button 56 is reset. This completes the latch. Next, when the rear cylinder 5 is rotated in the retreating direction, the piston 21 and the rod 3 cooperate to retreat with the compression spring 34 being compressed, and the inner surface of the tip end of the nozzle 2 and the cone of the piston 21 are rotated. A low-pressure chemical solution chamber 2d (see FIG. 2) is formed between the low-pressure chemical solution chamber 21a and the conical surface of the nozzle 21a.
Through the injection hole 2a.

Next, in order to obtain a necessary amount of chemical solution,
After aligning the tip of the rear cylinder 5 with a scale (not shown) on the surface of the front cylinder 4 and taking in a predetermined amount of drug solution, the vial adapter 8 is removed, the nozzle 2 is applied to the injection site of the patient, and the latch release button 56 is pressed. When pressed, slide ring 5
The inner surface at the tip of 7 rides over the latch ball 53, the latch ball 53 jumps out of the latch hole 35, and the rod 3 becomes free and moves forward at high speed. At this time, the piston 21 does not decelerate the initial speed due to the play of the long hole 3a, but gains momentum and moves the piston 21 forward. The chemical in the chemical chamber is compressed at a high pressure by the piston 21, and the injection holes 2a, 2
Subcutaneous injection is performed at a high speed from b and 2c.

At the time of the above injection, since the skin surface of the injection site is in close contact with the curved surface of the tip of the nozzle, the plurality of injection holes are maintained in a state of being abutted perpendicularly to the skin surface of the injection site. In addition, since the medicinal solution is injected through the narrow injection hole, no pain occurs at the time of injection.

In addition, in addition to the above embodiment, the number of injection holes of the nozzle 2 may be increased or decreased according to the injection amount, and the sizes may not be all the same. Furthermore, the shape of the nozzle tip may be a curved surface other than a spherical surface, for example, an elliptical curved surface. The plurality of injection holes are desirably formed in a direction perpendicular to these curved surfaces, but are not necessarily limited thereto.

[0018]

The needleless syringe of the present invention is constructed as described above. By using a plurality of injection holes, the injection holes can be made thin even when the injection amount is large. Then, the same pressure is applied from all the injection holes at the same pressure, and the drug solution is injected perpendicular to the skin surface at the injection site. It can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a needleless syringe using the nozzle of the present invention.

FIG. 2 is a sectional view showing the structure of the nozzle of the present invention.

FIG. 3 is a sectional view showing a combined state of the needleless syringe of the present invention and a drug solution vial.

FIG. 4 is a cross-sectional view of a nozzle used in a conventional needleless syringe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Needleless syringe 2, 10 ... Nozzle 2a, 2b, 2c, 10a ... Injection hole 2d ... Chemical solution chamber 3 ... Rod 3a ... Long hole 4 ... Front cylinder 5 ··· Rear cylinder 6 ··· Cylindrical body 7 ··· Chemical vial 8 ··· Vial adapter 8a ··· Case upper 8b ··· Case lower 9 ··· Suction needle 9a ··· Concave curved surface 9b · ··· Elastic members 11, 21 ··· Piston 21a ··· Conical body 21b ··· O-ring 21c ··· T-shaped connecting portion 31 ··· Flange ring 32 ··· Guide pipe 33 ··· Flange 34 55 ... compression spring 35 ... latch hole 36 ... recess 42, 43 ... screw part 51 ... protrusion 52 ... fixing ring 53 ... latch ball 54 ... small hole 56 ... Latch release button 57 ... Slide ring 58 ... moving small piece

Claims (1)

[Claims] 1. A needleless syringe for jetting a predetermined amount of a chemical solution from the injection hole of a nozzle at a tip end through the injection hole and injecting the liquid subcutaneously, wherein a plurality of injection holes are provided at the nozzle tip. Needleless syringe.