Sleeve for local anesthetic injection and injection assembly

Abstract

The invention discloses a sleeve for local anesthetic injection and an injection assembly, and relates to the technical field of injectors, the sleeve comprises a needle cylinder and a push rod which moves in the needle cylinder in the axial direction to boost liquid medicine, a piston is fixedly arranged at the end of the push rod, the sleeve comprises a needle seat which is arranged at the first end of the needle cylinder and used for supplying liquid to a needle head, and a liquid medicine tube is arranged on the needle seat; the adjusting sleeve is movably arranged in the axial direction and is driven by the spring to be kept in the initial state of enabling the liquid medicine tube to be unblocked. According to the sleeve for local anesthetic injection and the injection assembly, when the injection pressure is too large, the adjusting sleeve moves in the axial direction and is not in the initial state, so that the liquid medicine tube is blocked, liquid feeding is stopped, friction resistance generated by the expansion bag to the piston counteracts part of thrust F, the speed of the piston is low, the injection force is further reduced, and meanwhile the injection effect is improved. And through the arrangement of the pressure release valve, the liquid can automatically overflow into the liquid overflow cavity when the hydraulic pressure is too large, and the discomfort in the injection process can be reduced through the mode of reducing the hydraulic pressure.

Description

Technical Field

[0001] The invention relates to the technical field of syringes, in particular to a sleeve and an injection assembly for local anesthetic injection. Background Art

[0002] The sleeve and injection assembly for local anesthetic injection are mainly used for local anesthesia during surgery or other medical procedures, including syringes and other injection tools. The sleeve design should take into account easy operation and prevention of drug leakage, and usually has an adaptive interface to connect to the syringe.

[0003] In conjunction with publication number CN103338798A, publication date 2013-10-02, a syringe that also serves as a container is disclosed, comprising: an outer tube, the outer tube is formed into a cylindrical shape extending along an axis; a front plug, the front plug is embedded in the front end side of the outer tube; a rear plug, the rear plug is embedded in the rear end side of the outer tube, and a drug solution is enclosed between the rear plug and the front plug; a barrel mouth, the barrel mouth is embedded with the front end periphery of the outer tube through an embedding hole on the base end side, a bypass chamber for accommodating the front plug is provided on the front end side of the embedding hole, and a Luer head for installing an injection needle is provided; a finger handle, the finger handle is embedded with the rear end side of the outer tube; a piston rod, the piston rod is inserted into the outer tube from the rear end side of the outer tube and connected to the rear plug.

[0004] However, in the prior art including the above-mentioned patent, the drug solution will preferentially enter the bypass during the injection process, and the volume of the bypass is narrow, so that the hydraulic pressure of the drug solution increases after entering the bypass and is injected into the patient's body, resulting in the injection speed being too fast, which may cause swelling and even congestion at the injection site of the patient. Summary of the invention

[0005] The object of the present invention is to provide a sleeve and an injection assembly for local anesthetic injection, so as to solve the above-mentioned problems.

[0006] In order to achieve the above-mentioned object, the present invention provides the following technical solutions: a sleeve for local anesthetic injection, comprising a syringe and a push rod which moves axially inside to help push the liquid medicine, and a piston is fixedly arranged at the end of the push rod, comprising a needle seat which is arranged at the first end of the syringe and is used to supply liquid to the needle, and a liquid medicine tube is arranged on the needle seat;

[0007] An adjusting sleeve movably arranged along the axial direction and driven by a spring to maintain an initial state of keeping the medicine liquid tube unobstructed;

[0008] An overflow chamber is provided in the push rod and a pressure relief valve is provided on the overflow chamber;

[0009] A circumferential array of expansion bladders is disposed within the syringe and is used for the rate-limiting piston.

[0010] Preferably, the medicine liquid tube comprises a first liquid port and a second liquid port, and the inner wall of the adjustment sleeve is in close contact with the outer wall of the medicine liquid tube.

[0011] Preferably, the medicine liquid tube is provided with a bucket-shaped portion for gathering bubbles.

[0012] Preferably, the expansion bladder includes a folded portion having a fan-shaped expanded state.

[0013] Preferably, the expansion bag includes an elastic member that forms a retaining fit with the adjustment sleeve.

[0014] Preferably, it further comprises a limit plug for dividing the overflow chamber into a third chamber and a fourth chamber, wherein the third chamber is used to accommodate the medical liquid flowing through the pressure relief valve.

[0015] Preferably, the syringe is divided into a second chamber and a fifth chamber by a piston, and the fifth chamber is communicated with the fourth chamber.

[0016] Preferably, the fourth chamber is communicated with the expansion bladder.

[0017] Preferably, the pressure relief valve comprises a paddle movable along the axial direction and a fixed block, and the paddle and the block abut against each other to form a channel for the one-way flow of the drug solution.

[0018] An injection assembly comprises the sleeve for injecting local anesthetic drugs as described in the above scheme.

[0019] In the above technical scheme, a local anesthetic drug injection sleeve and injection assembly provided by the present invention have the following beneficial effects: when the push injection pressure is too large, the adjustment sleeve moves axially and is not in the initial state, so that the medicine tube is blocked and the liquid intake is stopped. The friction resistance generated by the expansion bag on the piston will offset part of the thrust F, so that the piston speed is slower, further reducing the push injection force. At the same time, through the setting of the pressure relief valve, the hydraulic pressure will automatically overflow into the overflow chamber when it is too large. By reducing the hydraulic pressure, the discomfort during the injection process can also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0021] Figure 1 An overall three-dimensional schematic diagram provided for an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the internal cross-sectional structure of a syringe provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the structure of the piston and the overflow chamber provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of a cross-sectional structure of a pressure relief valve provided in an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of a cutaway structure of a needle holder provided in an embodiment of the present invention;

[0026] Figure 6 A schematic diagram of an initial state of an expansion bladder provided by an embodiment of the present invention;

[0027] Figure 7 A schematic diagram of the expansion bladder in the expanded state provided by an embodiment of the present invention;

[0028] Figure 8 A schematic diagram of the normal operating structure of a pressure relief valve provided in an embodiment of the present invention;

[0029] Fig. 9 A schematic diagram of the structure of the pressure relief valve during pressure relief provided by an embodiment of the present invention;

[0030] Fig.10 A schematic diagram of the positions of the chambers in the syringe provided in an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1. Syringe; 11. Finger handle; 12. Needle seat; 2. Push rod; 21. Piston; 22. Pressure relief valve; 221. Fixing ring; 222. Retractable membrane; 223. Pick; 224. Block; 23. Limit plug; 24. Vent; 3. Adjustment sleeve; 31. Spring; 32. Stopper; 4. Liquid medicine tube; 41. First liquid port; 42. Bucket-shaped part; 43. Second liquid port; 5. Expansion bag; 51. Elastic part; 52. Folding part; 53. Through hole; 54. One-way air hole;

[0033] A, first chamber; B, second chamber; C, third chamber; D, fourth chamber; E, fifth chamber; F, sixth chamber. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] like Figure 1-10 As shown, a local anesthetic injection sleeve and injection assembly, including a syringe 1 and a push rod 2 that moves axially inside to help push the liquid medicine, and a piston 21 is fixedly arranged at the end of the push rod 2, including a needle seat 12 arranged at the first end of the syringe 1 and used to supply liquid to the needle, and a liquid medicine tube 4 is arranged on it;

[0036] An adjusting sleeve 3 is movably arranged along the axial direction and driven by a spring 31 to maintain an initial state in which the medicine liquid tube 4 is unobstructed;

[0037] An overflow chamber is provided in the push rod 2, on which a pressure relief valve 22 is provided;

[0038] A circumferential array of expansion bladders 5 is provided in the syringe 1 and is used for the speed-limiting piston 21 .

[0039] Specifically, it also includes a finger handle 11 arranged on the other end of the syringe 1 opposite to the needle, and the finger handle 11 is provided with an annular protrusion connected with the syringe 1 by interference fit, so that the syringe 1 and the finger handle 11 can be detachably assembled into one body.

[0040] Furthermore, the needle seat 12 is fixedly arranged on the syringe 1, and the liquid medicine tube 4 is fixedly arranged in the needle seat 12, and the adjustment sleeve 3 is slidably arranged in the syringe 1. During use, the operator pushes the push rod 2, and the spring 31 is neither contracted nor stretched when the thrust is low. At this time, the spring 31 supports the adjustment sleeve 3 and the liquid medicine tube 4 to remain in the initial state, so that the liquid medicine tube 4 can normally feed the needle. Corresponding openings can be opened on the liquid medicine tube 4 and the adjustment sleeve 3, and the liquid medicine tube 4 is unobstructed when the openings overlap; or a plug block consistent with the inner diameter of the adjustment sleeve 3 is set on the liquid medicine tube 4, and the gap between the liquid medicine tube 4 and the adjustment sleeve 3 is used as the liquid outlet space, or other structures that keep the adjustment sleeve 3 unobstructed with the liquid medicine tube 4 in the initial state are all acceptable.

[0041] When the pushing pressure is too large, the piston 21 applies a thrust F to the liquid medicine, and the liquid medicine transmits the force to the adjusting sleeve 3 and causes the spring 31 to contract. At this time, the adjusting sleeve 3 moves axially and is not in the initial state, so that the liquid medicine tube 4 is blocked and the liquid is stopped, so as to avoid discomfort to the patient caused by too fast injection. In addition, a groove that fits tightly with the expansion bag 5 is provided on the piston 21. The piston 21 is embedded in the syringe 1 in a liquid-tight manner and is restricted by the inner wall of the syringe 1, so that the piston 21 is kept in a reduced diameter state smaller than the original outer diameter. The friction resistance generated by the expansion bag 5 on the piston 21 will offset part of the thrust F, so that the piston 21 speed is slower, further reducing the injection force. At the same time, the pressure relief valve 22 is set so that the excessive hydraulic pressure will automatically overflow into the overflow chamber, and the discomfort during the injection process can also be reduced by reducing the hydraulic pressure.

[0042] In the above technology, when the push injection pressure is too large, the adjustment sleeve 3 moves axially and is not in the initial state, so that the medicine tube 4 is blocked and the liquid inlet is stopped. The friction resistance generated by the expansion bag 5 on the piston 21 will offset part of the thrust F, making the piston 21 slower, further reducing the push injection force. At the same time, through the setting of the pressure relief valve 22, the hydraulic pressure will automatically overflow into the overflow chamber when it is too large. By reducing the hydraulic pressure, the discomfort during the injection process can also be reduced.

[0043] As an embodiment further provided by the present invention, the medicine liquid tube 4 includes a first liquid port 41 and a second liquid port 43 , and the inner wall of the adjustment sleeve 3 is tightly fitted with the outer wall of the medicine liquid tube 4 .

[0044] Specifically, the adjusting sleeve 3 includes a conical portion that is consistent with the end surface of the piston 21, and a cylindrical structure is provided at the end of the conical portion. The inner wall of the cylindrical structure is tightly fitted with the outer wall of the liquid medicine tube 4, so that the adjusting sleeve 3 slides along the circumference of the liquid medicine tube 4. In the initial state of the adjusting sleeve 3, the cylindrical structure is located between the first liquid port 41 and the second liquid port 43. At this time, the syringe 1 is divided into a first chamber A and a second chamber B with the adjusting sleeve 3 as the boundary, wherein the first chamber A is located in the needle seat 12, and the second chamber B is located in the needle seat 12. Figure 5 The structure shown is for reference.

[0045] In the initial state, the medicine liquid is pushed by the piston 21 into the second liquid port 43 in the second chamber B, and then passes through the medicine liquid tube 4 and enters the first chamber A through the first liquid port 41. When the push pressure is too large, the medicine liquid will push the adjusting sleeve 3 to slide toward the first chamber A, and the cylindrical mechanism closes the first liquid port 41, so that the medicine liquid cannot pass through, and the liquid injection into the first chamber A is automatically stopped. In addition, since the volume of the first chamber A is reduced during the sliding process of the adjusting sleeve 3 toward the first chamber A, the hydraulic pressure in the first chamber A is slightly increased. Under this hydraulic pressure, the first chamber A is still under positive pressure and automatically injects liquid into the patient's body to prevent the patient from bleeding back due to a sudden cessation of liquid injection.

[0046] As another embodiment further provided by the present invention, a bucket-shaped portion 42 for gathering bubbles is provided on the medicine liquid tube 4.

[0047] Specifically, the narrow part of the bucket-shaped portion 42 faces the first liquid port 41, and the wide part faces the second liquid port 43, and the inside of the bucket-shaped portion 42 is connected to the second liquid port 43. In the initial state, the bucket-shaped portion 42 is tightly fitted with the inner wall of the adjustment sleeve 3. Before the push injection, the needle tip of the syringe 1 filled with liquid medicine is first pointed upward, so that the bubbles automatically float upward under the action of gravity and gather in the bucket-shaped portion 42, and then the push rod 2 is pushed at a relatively fast speed to move the adjustment sleeve 3 toward the first chamber A. The adjustment sleeve 3 closes the first liquid port 41, and the bubbles stay in the liquid medicine tube 4. At this time, the pressure in the second chamber B is relatively large and continuously squeezes the bubbles, so that multiple bubbles are broken, which plays a role in defoaming and prevents larger bubbles from being directly pushed into the patient's body.

[0048] Furthermore, during the process of sucking the medicine liquid, the medicine liquid enters the second liquid port 43 from the first liquid port 41 and then enters the second chamber B. Even if the suction force is strong enough to cause the adjustment sleeve 3 to slide, the adjustment sleeve 3 will be blocked by the bucket-shaped portion 42 and will not block the second liquid port 43, thereby ensuring that the suction can be completed quickly during the process of sucking the medicine liquid.

[0049] As another embodiment further provided by the present invention, the expansion bladder 5 includes a folded portion 52 in a fan-shaped expanded state.

[0050] Specifically, the end of the expansion bag 5 close to the needle is the first end, and the opposite end is the second end. The second end of the expansion bag 5 is rotatably arranged on the inner wall of the syringe 1, wherein an anti-slip pad is arranged on the side where the expansion bag 5 and the piston 21 slide together. The folding portion 52 is fan-shaped when unfolded, and the thickness of the folding portions 52 increases along the injection direction. The inner diameter formed by the folding portions 52 gradually decreases, so that the resistance of the piston 21 gradually increases during the sliding process along the axial diameter direction of the syringe 1, so that the injection speed of the staff is slowed down.

[0051] As another embodiment further provided by the present invention, the expansion bag 5 includes an elastic member 51 that forms a retaining fit with the adjustment sleeve 3 .

[0052] Specifically, the expansion bag 5 is also fixedly provided with a one-way air hole 54, which is set on the syringe 1 to allow external air to enter the expansion bag 5. The adjustment sleeve 3 is provided with a stopper 32 for pressing the elastic member 51. When the pushing pressure is too large, the medicine will push the adjustment sleeve 3 to slide into the first chamber A. At this time, the stopper 32 and the elastic member 51 are staggered, and the elastic member 51 is released to expand the first end of the expansion bag 5. The second end of the expansion bag 5 remains in place, so that the folded portion 52 is fan-shaped. As the internal volume of the expansion bag 5 expands, the external air is sucked into the expansion bag 5 through the one-way air hole 54, and the expansion bag 5 can be automatically expanded when the pressure is too large without other pneumatic sources.

[0053] As another embodiment further provided by the present invention, it also includes a limit plug 23 for dividing the overflow chamber into a third chamber C and a fourth chamber D. The third chamber C is used to accommodate the liquid medicine flowing through the pressure relief valve 22.

[0054] Specifically, the stopper 23 is slidably disposed in the overflow cavity, and a plurality of rollers are disposed on the stopper 23 to reduce the friction resistance with the inner wall of the overflow cavity. When the pressure in the second cavity B is too high, the liquid medicine enters the third cavity C through the pressure relief valve 22, and the stopper 23 is driven to slide under the pushing of the liquid medicine, so that the volume of the third cavity C is consistent with the volume of the overflowed liquid medicine.

[0055] However, since there is a certain amount of air in the overflow cavity, the limit plug 23 reduces the volume of the fourth chamber D when being pushed by the liquid medicine, and the air is squeezed and generates a certain pressure, which prevents the liquid medicine from entering.

[0056] As an embodiment further provided by the present invention to solve the above-mentioned problem, the syringe 1 is divided into a second chamber B and a fifth chamber E by the piston 21, and the fifth chamber E is communicated with the fourth chamber D.

[0057] Specifically, during the process of pushing the medicine, the medicine in the second chamber B is continuously reduced, and the volume in the fifth chamber E is gradually expanded. The fifth chamber E is originally in a relatively sealed state, and the volume is expanded but the amount of gas remains unchanged, so that the fifth chamber E is under negative pressure. Through the vent hole 24 opened on the push rod 2, the excess air in the fourth chamber D is sucked into the fifth chamber E. When the pushing speed is too fast, the negative pressure suction force generated by the fifth chamber E will actively suck the fourth chamber D, so that the limit plug 23 automatically moves toward the direction close to the fourth chamber D and draws the medicine in the second chamber B into the third chamber C, thereby reducing the hydraulic pressure in the second chamber B at this time, thereby offsetting the high pressure generated when the pushing speed is too fast.

[0058] As another embodiment further provided by the present invention, the fourth chamber D is communicated with the expansion bladder 5 .

[0059] Specifically, the thickness of the multiple folded portions 52 increases gradually along the push direction, and the piston 21 gradually increases the degree of squeezing of the expansion bag 5 during the push process. The squeezed gas in the expansion bag 5 will enter the fifth chamber E through the multiple through holes 53 opened at the second end of the expansion bag 5, and then enter the fourth chamber D through the vent 24, so that the limit plug 23 approaches the direction of the third chamber C and squeezes the overflowed medicine originally in the third chamber C back into the second chamber B, avoiding waste of medicine.

[0060] As another embodiment further provided by the present invention, the pressure relief valve 22 includes a paddle 223 movable along the axial direction and a fixed block 224, and the paddle 223 and the block 224 abut against each other to form a channel for the one-way flow of the liquid medicine.

[0061] Specifically, it also includes a fixed ring 221, which is fixedly arranged at the port of the third chamber C, and a block 224 is fixedly arranged at the center of the fixed ring 221, and a retractable membrane 222 is arranged between the paddle 223 and the fixed ring 221, so that the paddle 223 and the block 224 are kept against each other under the pulling of the retractable membrane 222. Under normal pressure, the paddle 223 is blocked by the block 224, and the piston 21 forms a closed end surface for squeezing the liquid medicine. Only when the pressure in the second chamber B is too large, the reaction force f generated by the liquid medicine to the thrust F pushes the paddle 223, so that the retractable membrane 222 is expanded, and at this time, a gap appears between the paddle 223 and the block 224, and the liquid medicine can enter the overflow chamber. And when the paddle 223 and the block 224 are against each other, a closed end surface is formed as follows. Figure 4 In the structure shown, the inner wall of the paddle 223 is in close contact with the arc surface of the blocking block 224 and forms an acute angle structure, so that the medicine liquid can flow along the tip of the acute angle. When the limit plug 23 approaches the direction of the third chamber C, the medicine liquid in the third chamber C is pushed by the limit plug 23 and flows into the second chamber B.

[0062] Working principle: before pushing the injection, first point the needle tip of the syringe 1 filled with liquid medicine upward, so that the bubbles automatically float upward under the action of gravity and gather in the bucket-shaped part 42, then push the push rod 2 at a relatively fast speed to move the adjustment sleeve 3 toward the first chamber A, and the adjustment sleeve 3 closes the first liquid port 41, and the bubbles stay in the liquid medicine tube 4. At this time, the pressure in the second chamber B is relatively large and continuously squeezes the bubbles, so that multiple bubbles are broken, thereby achieving the effect of defoaming.

[0063] In the initial state, the medicine liquid is pushed by the piston 21 into the second liquid port 43 in the second chamber B, and then passes through the medicine liquid tube 4 and enters the first chamber A through the first liquid port 41. When the push injection pressure is too large, the medicine liquid will push the regulating sleeve 3 to slide into the first chamber A, and the cylindrical mechanism will close the first liquid port 41, so that the medicine liquid cannot pass through, and the liquid intake into the first chamber A will automatically stop.

[0064] At this time, the blocking member 32 is offset from the elastic member 51, the elastic member 51 is released and the first end of the expansion bag 5 is unfolded, and the second end of the expansion bag 5 remains in place, so that the folded portion 52 is fan-shaped and expanded. As the internal volume of the expansion bag 5 expands, the outside air is sucked into the expansion bag 5 through the one-way air hole 54.

[0065] During the injection process, the piston 21 gradually increases the degree of squeezing of the expansion bag 5. The squeezed gas in the expansion bag 5 enters the fifth chamber E through the multiple through holes 53 opened at the second end of the expansion bag 5, and then enters the fourth chamber D through the vent 24, so that the limit plug 23 approaches the third chamber C and squeezes the overflowed liquid originally in the third chamber C back into the second chamber B.

[0066] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A local anesthetic injection sleeve, comprising a syringe (1) and a push rod (2) which moves axially therein to help push the liquid medicine, and a piston (21) is fixedly arranged at the end of the push rod (2), characterized in that: It comprises a needle seat (12) arranged at the first end of the syringe (1) and used for supplying liquid to the needle, and a liquid medicine tube (4) is arranged on the needle seat; An adjusting sleeve (3) movably arranged along the axial direction and driven by a spring (31) to maintain an initial state in which the medicine liquid tube (4) is unobstructed; An overflow chamber is formed in the push rod (2) and is provided with a pressure relief valve (22); The circumferential array is arranged in the syringe (1) and is used for the expansion bag (5) of the speed limiting piston (21).

2. The local anesthetic injection sleeve according to claim 1, characterized in that: The medicine liquid tube (4) comprises a first liquid port (41) and a second liquid port (43), and the inner wall of the adjustment sleeve (3) is tightly fitted with the outer wall of the medicine liquid tube (4).

3. The local anesthetic injection sleeve according to claim 1, characterized in that: The liquid medicine tube (4) is provided with a bucket-shaped portion (42) for gathering bubbles.

4. The local anesthetic injection sleeve according to claim 1, characterized in that: The expansion bag (5) comprises a folded portion (52) in a fan-shaped expanded state.

5. The local anesthetic injection sleeve according to claim 1, characterized in that: The expansion bag (5) comprises an elastic member (51) which forms a retaining fit with the adjustment sleeve (3).

6. The local anesthetic injection sleeve according to claim 1, characterized in that: It also includes a limit plug (23) for dividing the overflow chamber into a third chamber (C) and a fourth chamber (D), wherein the third chamber (C) is used to accommodate the medical liquid flowing through the pressure relief valve (22).

7. The local anesthetic injection sleeve according to claim 6, characterized in that: The syringe (1) is divided into a second chamber (B) and a fifth chamber (E) by a piston (21), and the fifth chamber (E) is communicated with the fourth chamber (D).

8. The local anesthetic injection sleeve according to claim 6, characterized in that: The fourth chamber (D) is communicated with the expansion bladder (5).

9. The local anesthetic injection sleeve according to claim 1, characterized in that: The pressure relief valve (22) comprises a paddle (223) movable along the axial direction and a fixed block (224), and the paddle (223) and the block (224) are pressed against each other to form a channel for the unidirectional flow of the liquid medicine.

10. An injection assembly, characterized in that: A sleeve for local anesthetic injection comprising the sleeve according to any one of claims 1 to 9.

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