Novel safety injection syringe

Abstract

A novel safety injection syringe comprises a sheath, a needle tube, a needle bed, an absorption gasket, a damping ring, a piston, a push rod and an outer cylinder; the edge of a taper hole is bent inwards to form a ring-shaped sharp bulge, and air seal is formed between the bulge and the plane where the front segment and the middle segment of the needle bed are jointed; the internal diameter of the adsorption gasket and the internal diameter of the damping ring are slightly smaller than the external diameter of the rear segment of the needle bed and greater than the external diameter of the middle segment of the needle bed, and the adsorption gasket and the damping ring are arranged at the bottom of the rear segment of the needle bed in a sleeving manner and then are mounted in an inner cavity at the front end of the outer cylinder, so that air-gas seal is formed among the needle bed, the damping ring and the outer cylinder; a front plug is mounted in a narrow opening in the front end of the push rod, and the piston is mounted on the outer side at the front end of the push rod and is sealed together with the inner wall of the outer cylinder in a sliding manner. After injection, the push rod continues to be pressed, the lower end of the needle bed is in embedded connection with the front plug and moves downwards to open the inner cavity of the push rod, the push rod enables the adsorption gasket and the damping ring to move forwards to compress air in the inner cavity of the front segment of the outer cylinder, the needle bed is released when the damping ring moves forwards to the middle segment of the need bed, and the compressed air forces the needle tube on the needle bed into the inner cavity of the push rod to enable the front plug to be in embedded connection with a tapered column at the bottom of the push rod, so that the needle tube is screened and cannot be exposed; residual liquor is absorbed by the adsorption gasket. The novel safety injection syringe has the characteristics of simplicity, practicality, safety and reliability.

Description

(1) Technical field [0001] The invention relates to a medical instrument, in particular to a novel safety syringe used for puncturing human tissue and injecting medicine into the tissue or extracting tissue samples after puncturing. (two), background technology [0002] Chinese Patent Application No. 201210221311.1 discloses a pneumatic retractable self-destructing syringe, which includes a syringe, a cylindrical hollow injection rod, a needle seat, a gasket, a piston and a sealing joint. The sealing gasket at the lower end is installed on the front end of the injection barrel, the piston sleeve is set on the outside of the front end of the injection rod, the sealing joint is set on the inner side of the front end of the injection rod, and the sealing joint and the needle seat are provided with a connecting structure that cooperates with each other. It is characterized in that : When the injection rod is pushed to the front end of the injection barrel, the inner wall of the ...

AI Technical Summary

Problems solved by technology

[0003] Although this technical solution and the application number 201310057218.6 have made great progress compared with the previous self-destruct or safety syringes that use mechanical force (spring force or artificial tension) to retract the needle seat and needle tube, the above case uses air power to make the needle seat retract. The technical solution of retraction is not suitable for triggering retraction in human tissue because: the injection environment is complex (injection into intradermal, subcutaneous, intramuscular, tissue or organ, nerve plexus, intravascular, sheath cavity, joint Cavity, bone, etc.), the most common is intramuscular injection, the patient often suffers from needle stagnation due to tension and muscle contraction (the needle is clamped and difficult to pull out), at this time the air pressure is difficult to overcome the resistance of the needle stagnation, compression Once the air is released, the needle cannot be retracted, losing the function of self-destruct and needle retraction

Thus, the above-mentioned scheme still has the following deficiencies: 1. Whether it is the technical scheme of retracting the needle by mechanical force or the above-mentioned air pressure, as long as it is a technical scheme that separates the needle seat (retraction or forward movement) from the overcoat, injection of the outer cylinder will occur. The phenomenon that the residual medicine liquid in the inner cylinder sprays back and forth to the cone hole of the outer cylinder

Therefore, the description of the above-mentioned technical solution is only that the sealing gasket moves forward from the position-limiting seat to the middle of the needle seat. This distance is difficult to achieve the required pressure for the compression of the air in the inner cavity of the front end of the syringe, especially for small specifications (less than 1.0ml) of the syringe, the diameter of the inner cavity of the injection barrel is less than 4.0mm, and the thickness of the general gasket is about 2-3.0mm; such a compression distance, the air pressure is extremely weak, and the needle seat retraction described in the above scheme cannot be realized Required; ③, because this scheme utilizes the structure that the inner hole at the lower end of the needle seat and the plug at the front end of the sealing joint are connected to each other, so that the two can drive the needle tube to retract together into the inner cavity of the injection rod; due to the gap between the inner hole of the needle seat and the sealing joint The existing connection space increases the amount of drug residues, especially expensive drugs, which will cause drug waste and reduce the curative effect; this is also the reason why the solution is sprayed to the front of the cone hole in the triggered state; ④, because the solution is Using the interaction between the bottom edge of the sealing joint and the three ribs in the middle and lower parts of the injection rod, the needle can be limited so that it cannot be shot from the lower end of the injection rod, and it cannot be exposed from the upper hole of the injection rod

Due to the shortcomings or defects of the above-mentioned point ② in this solution, its retraction is uncertain, especially when the small-sized syringe does not retract; then the needle, needle seat and sealing joint may retract (inject) together. : Incomplete entry into the inner cavity of the injection rod, that is, the needle, the needle seat and the sealing joint are not ejected by enough compressed air and retracted between the two limit devices, then the needle tip cannot fully enter the inner cavity of the injection rod, and Continued exposure, risk of needlestick injury

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