Sleeves and injection components for local anesthetic injection

Abstract

The present invention discloses a sleeve and injection assembly for local anesthetic injection, which relates to the technical field of syringes, and comprises a syringe and a push rod therein that moves axially to assist in pushing the liquid medicine, wherein a piston is fixedly provided at the end of the push rod, and comprises a needle seat provided at the first end of the syringe and used to supply liquid to the needle, on which a liquid medicine tube is provided; and an adjustment sleeve provided for movement along the axial direction, which is driven by a spring to maintain an initial state in which the liquid medicine tube is unobstructed. When the injection pressure of the sleeve and injection assembly for local anesthetic injection is too high, the adjustment sleeve moves axially and is not in the initial state, so that the liquid medicine tube is blocked and liquid intake is stopped. The frictional resistance generated by the expansion bladder on the piston will offset part of the thrust F, making the piston speed slower and further reducing the injection force. At the same time, the setting of the pressure relief valve allows the liquid to overflow into the overflow chamber automatically when the hydraulic pressure is too high. By reducing the hydraulic pressure, the discomfort during the injection process can also be reduced.

Description

Technical Field

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

[0002] Local anesthetic injection sleeves and injection components 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 barrel, the outer barrel being formed into a cylindrical shape extending along an axis; a front plug, the front plug being embedded in the front end side of the outer barrel; a rear plug, the rear plug being embedded in the rear end side of the outer barrel, and encapsulating a medicinal solution between the rear plug and the front plug; a barrel mouth, the barrel mouth being embedded with the front end outer periphery of the outer barrel through an embedding hole on the base end side, a bypass chamber for accommodating the front plug being provided on the front end side of the embedding hole, and a Luer head for installing an injection needle being provided; a finger handle, the finger handle being embedded with the rear end side of the outer barrel; a piston rod, the piston rod being inserted into the outer barrel from the rear end side 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 relatively 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 an injection speed that is too fast, which may cause swelling or even congestion at the patient's injection site. Summary of the Invention

[0005] The purpose of the present invention is to provide a local anesthetic injection sleeve and an injection assembly to solve the above problems.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solution: a local anesthetic injection sleeve, comprising a syringe and a push rod that moves axially therein to assist in pushing the liquid medicine, wherein a piston is fixedly provided at the end of the push rod, and a needle seat is provided at the first end of the syringe and is used to supply liquid to the needle, and a liquid medicine tube is provided on the needle seat;

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

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

[0009] A circumferential array is provided within the syringe and serves as an expansion bladder for the rate-limiting piston.

[0010] Preferably, the medicine liquid tube includes 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 liquid medicine 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 includes a limit plug for dividing the overflow chamber into a third chamber and a fourth chamber, and 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 liquid medicine.

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

[0019] In the above technical solution, the present invention provides a local anesthetic drug injection sleeve and injection assembly, which have the following beneficial effects: when the push 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, making the piston speed slower, further reducing the push 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 following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described 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 piston and overflow chamber structure provided by an embodiment of the present invention;

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

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

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

[0027] Figure 7 A schematic diagram of the expanded 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 by an embodiment of the present invention;

[0029] Figure 9 A schematic structural diagram of a pressure relief valve during pressure relief provided by an embodiment of the present invention;

[0030] Figure 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. Retaining ring; 222. Retractable membrane; 223. Pick; 224. Block; 23. Stop plug; 24. Vent; 3. Adjustment sleeve; 31. Spring; 32. Stopper; 4. Liquid medicine tube; 41. First liquid port; 42. Bucket-shaped portion; 43. Second liquid port; 5. Expansion bladder; 51. Elastic member; 52. Folding portion; 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 includes a syringe 1 and a push rod 2 that moves axially therein to help push the liquid medicine, and a piston 21 is fixedly provided at the end of the push rod 2. It includes a needle seat 12 provided at the first end of the syringe 1 and used to supply liquid to the needle, and a liquid medicine tube 4 is provided on the needle seat;

[0036] An adjusting sleeve 3 is axially movable 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 and a pressure relief valve 22 is provided on the overflow chamber;

[0038] A circumferential array of expansion bladders 5 is provided in the syringe 1 and serves to limit the speed of the piston 21 .

[0039] Specifically, it also includes a finger handle 11 provided on the other end of the syringe 1 opposite to the needle head. The finger handle 11 is provided with an annular protrusion that is interference-fitted with the syringe 1, 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 mounted on the syringe 1, and the liquid medicine tube 4 is fixedly mounted in the needle seat 12, and the adjustment sleeve 3 is slidably mounted 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 when the openings overlap, the liquid medicine tube 4 is unobstructed; or a plug with the same inner diameter as the adjustment sleeve 3 can be set on the liquid medicine tube 4, with the gap between the liquid medicine tube 4 and the adjustment sleeve 3 as the liquid outlet space; or other structures can be used to ensure that the adjustment sleeve 3 and the liquid medicine tube 4 remain unobstructed in the initial state.

[0041] When the pushing pressure is too great, the piston 21 applies a thrust F to the liquid medicine, which transmits force to the regulating sleeve 3 and causes the spring 31 to contract. At this point, the regulating sleeve 3 moves axially and is no longer in its initial state, blocking the liquid medicine tube 4 and stopping the inflow of liquid, thus preventing the patient from experiencing discomfort due to excessive injection. Furthermore, the piston 21 is provided with a groove that fits tightly with the expansion bladder 5. The piston 21 is fluid-tightly embedded within the syringe 1 and constrained by the inner wall of the syringe 1, maintaining a reduced diameter smaller than its original outer diameter. The frictional resistance exerted by the expansion bladder 5 on the piston 21 offsets some of the thrust F, slowing the piston 21 and further reducing the injection force. At the same time, the pressure relief valve 22 is configured to automatically overflow into the overflow chamber when the hydraulic pressure is excessive. This lowering of the hydraulic pressure can also reduce discomfort during the injection process.

[0042] In the above technology, when the push pressure is too high, the adjustment sleeve 3 moves axially and is not in the initial state, so that the medicine tube 4 is blocked and the liquid inflow stops. The friction resistance generated by the expansion bag 5 on the piston 21 will offset part of the thrust F, making the piston 21 move slower, further reducing the push 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 high. 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 in close contact with the outer wall of the medicine liquid tube 4 .

[0044] Specifically, the adjustment sleeve 3 includes a tapered portion that is consistent with the end surface of the piston 21, and the end of the tapered portion is provided with a cylindrical structure. The inner wall of the cylindrical structure is tightly fitted with the outer wall of the liquid medicine tube 4, so that the adjustment sleeve 3 slides along the circumference of the liquid medicine tube 4. In the initial state of the adjustment sleeve 3, the cylindrical structure is located between the first liquid port 41 and the second liquid port 43. At this time, the adjustment sleeve 3 is used as the boundary to divide the syringe 1 into a first chamber A and a second chamber B, 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 is pushed by the piston 21 into the second liquid port 43 in the second chamber B, and then passes through the medicine tube 4 and enters the first chamber A through the first liquid port 41. When the injection pressure is too large, the medicine will push the adjustment sleeve 3 to slide toward the first chamber A, and the cylindrical mechanism closes the first liquid port 41, so that the medicine cannot pass through, and the liquid is automatically stopped from entering the first chamber A. In addition, since the volume of the first chamber A decreases during the sliding of the adjustment sleeve 3 toward the first chamber A, the hydraulic pressure in the first chamber A increases slightly. Under this hydraulic pressure, the first chamber A is still at positive pressure and automatically injects liquid into the patient's body to prevent the sudden cessation of liquid injection from causing blood back to the patient.

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

[0047] Specifically, the narrow portion of the bucket-shaped portion 42 faces the first liquid inlet 41, and the wide portion faces the second liquid inlet 43. The inside of the bucket-shaped portion 42 is connected to the second liquid inlet 43. In the initial state, the bucket-shaped portion 42 is tightly fitted against the inner wall of the adjustment sleeve 3. Before performing a push injection, the needle tip of the syringe 1, which is filled with liquid medicine, is first pointed upward, so that bubbles automatically float upward under the action of gravity and gather in the bucket-shaped portion 42. 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 inlet 41, and the bubbles remain in the liquid medicine tube 4. At this time, the pressure in the second chamber B is relatively high and continuously squeezes the bubbles, causing multiple bubbles to break, thereby playing a defoaming role and preventing larger bubbles from being directly pushed into the patient's body.

[0048] Furthermore, during the process of sucking the liquid medicine, the liquid medicine 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 liquid medicine.

[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 bladder 5 closest to the needle is the first end, and the opposite end is the second end. The second end of the expansion bladder 5 is rotatably mounted on the inner wall of the syringe 1. A non-slip pad is provided on the side of the expansion bladder 5 where it slides with the piston 21. When unfolded, the folded portion 52 is fan-shaped, with the thickness of the folded portions 52 increasing along the injection direction. The inner diameter enclosed by the folded portions 52 gradually decreases, increasing the resistance of the piston 21 as it slides along the axial diameter of the syringe 1, slowing the injection speed.

[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 capsule 5 is further fixedly provided with a one-way air hole 54, which is provided through the syringe 1 to allow outside air to enter the expansion capsule 5. The adjustment sleeve 3 is provided with a stopper 32 for pressing the elastic member 51. When the pushing pressure is too high, the medical liquid 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, causing the first end of the expansion capsule 5 to unfold. The second end of the expansion capsule 5 remains in place, causing the folded portion 52 to unfold in a fan shape. As the internal volume of the expansion capsule 5 expands, outside air is sucked into the expansion capsule 5 through the one-way air hole 54. No other pneumatic source is required to automatically inflate the expansion capsule 5 when the pressure is too high.

[0053] As another embodiment further provided by the present invention, it further 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, a stopper 23 slides within the overflow chamber and is equipped with multiple rollers to reduce friction with the inner wall of the overflow chamber. When the pressure in the second chamber B is too high, the liquid medicine flows through the pressure relief valve 22 into the third chamber C. The pressure of the liquid medicine pushes the stopper 23, causing the volume of the third chamber C to match 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 it is 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 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 liquid, the medicine liquid in the second chamber B is continuously reduced, and the volume in the fifth chamber E is gradually expanded. The original fifth chamber E is 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 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 liquid in the second chamber B into the third chamber C, 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 degree of squeezing of the expansion bladder 5 by the piston 21 gradually increases during the push process. The squeezed gas in the expansion bladder 5 enters the fifth chamber E through the multiple through holes 53 opened at the second end of the expansion bladder 5, and then enters 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 liquid medicine originally in the third chamber C back into the second chamber B, thereby avoiding waste of liquid 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 provided between the paddle 223 and the fixed ring 221. Under the pull of the retractable membrane 222, the paddle 223 and the block 224 are kept in contact with each other. Under normal pressure, the paddle 223 is blocked by the block 224, and the piston 21 forms a closed end face for squeezing the liquid medicine. Only when the pressure in the second chamber B is too high, the reaction force f generated by the liquid medicine to the thrust F pushes the paddle 223, causing the retractable membrane 222 to expand. 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 in contact with each other, a gap 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 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 performing a push 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. The bubbles remain in the liquid medicine tube 4. At this time, the pressure in the second chamber B is relatively high and continues to squeeze the bubbles, causing multiple bubbles to break, thereby achieving a defoaming effect.

[0063] In the initial state, the liquid medicine is pushed by the piston 21 into the second liquid port 43 in the second chamber B, and then passes through the liquid medicine tube 4 and enters the first chamber A through the first liquid port 41. When the injection pressure is too high, the liquid medicine will push the regulating sleeve 3 to slide toward the first chamber A, and the cylindrical mechanism will close the first liquid port 41, preventing the liquid medicine from passing through, and automatically stopping the liquid from entering the first chamber A.

[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. 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 compression of the expansion bladder 5. The compressed gas in the expansion bladder 5 enters the fifth chamber E through the multiple through holes 53 opened at the second end of the expansion bladder 5, and then enters 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 liquid originally in the third chamber C back into the second chamber B.

[0066] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A local anesthetic injection sleeve, comprising a syringe and a push rod that moves axially to push the liquid medicine, and a piston is fixedly provided at the end of the push rod, characterized in that: It includes a needle seat arranged at the first end of the syringe and used for supplying liquid to the needle, and a liquid medicine tube is arranged on the needle seat; An adjusting sleeve movably arranged along the axial direction and driven by a spring to maintain an initial state in which the medicine liquid tube is unobstructed; An overflow chamber is provided in the push rod and is provided with a pressure relief valve; A circumferential array of expansion bladders disposed within the syringe and serving to limit the speed of the piston; The liquid medicine 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 liquid medicine tube; The liquid medicine tube is provided with a bucket-shaped portion for gathering bubbles; The adjusting sleeve includes a tapered portion that is consistent with the end surface of the piston, and a cylindrical structure is provided at the end of the tapered portion. The inner wall of the cylindrical structure is tightly fitted with the outer wall of the liquid medicine tube, so that the adjusting sleeve slides along the circumference of the liquid medicine tube. In the initial state of the adjusting sleeve, the cylindrical structure is located between the first liquid port and the second liquid port. The narrow part of the bucket-shaped portion faces the first liquid port, the wide part faces the second liquid port, and the inside of the bucket-shaped portion is connected to the second liquid port. In the initial state, the bucket-shaped portion is tightly fitted to the inner wall of the adjustment sleeve.

2. The local anesthetic injection sleeve according to claim 1, characterized in that: The expansion bladder includes a folded portion having a fan-shaped expanded state.

3. The local anesthetic injection sleeve according to claim 1, characterized in that: The expansion bag includes an elastic member that forms a blocking fit with the adjustment sleeve.

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

5. The local anesthetic injection sleeve according to claim 4, characterized in that: 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.

6. The local anesthetic injection sleeve according to claim 4, characterized in that: The fourth chamber is communicated with the expansion bladder.

7. The local anesthetic injection sleeve according to claim 1, characterized in that: The pressure relief valve comprises a paddle movable along the axial direction and a fixed block, and the paddle and the block are pressed against each other to form a channel for the one-way flow of the liquid medicine.

8. An injection assembly, characterized in that The local anesthetic injection sleeve comprises the sleeve according to any one of claims 1 to 7.

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