A pneumatic needle-free injector and method of use thereof

Abstract

The present application belongs to the field of syringe, and particularly relates to a kind of pneumatic needleless syringe and its using method, including syringe body, Laval air pipe and liquid medicine injection speed control mechanism;One end of the Laval air pipe is connected with the air chamber cavity of the syringe body, the other end is used to connect gas supply device;The liquid medicine injection speed control mechanism includes the baffle that can adjust the throat opening of the Laval air pipe and the controller for controlling the baffle to increase the throat opening after setting time at the beginning of injection.The pneumatic needleless syringe provided by the present application improves the jet speed on the basis of the consistent gas supply pressure of gas supply device, and can realize the injection of two kinds of liquid medicine jet speed, prevents liquid medicine splashing, improves liquid medicine utilization rate, reduces the risk of injection pain and tissue damage caused by injection too deep.

Description

Technical Field

[0001] The invention belongs to the field of syringes, and in particular relates to a pneumatic needle-free syringe and a method for using the same. Background Art

[0002] Needle-free injection, a novel injection method, utilizes a power source to generate instantaneous high pressure to propel the drug solution through a nozzle, forming a high-speed, high-pressure microjet. This jet penetrates the skin and diffuses into subcutaneous or intramuscular tissue. Ideally, a high jet velocity ensures penetration and precise injection. Once the target injection depth is reached, a lower jet velocity is used for diffusion to prevent backflow and ensure injection completion.

[0003] Based on this, the Chinese invention patent "CN112412733A - Double-channel needle-free injection device and method with controllable jet velocity" provides a device and method for needle-free injection using two channels to achieve two flow rates. However, this method still has certain disadvantages. For example, the dual channels must be filled with liquid medicine, which will cause liquid medicine to be retained in the infusion tube after injection, resulting in liquid medicine waste. Switching the flow channel delivery will affect the continuity of liquid medicine delivery. In addition, it is impossible to adjust the jet velocity. At the same time, most current pneumatic needle-free injection devices use a constant pressure for injection, that is, the pressure required to penetrate the epidermis. However, in the actual injection process, different jet velocities are required due to differences in patient constitution, injection site, and injection depth. When the jet velocity is too low, it cannot reach the specified depth. When the jet velocity is too high, it may cause drug splashing and severe pain at the injection site, seriously affecting the completion rate of the injection. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a pneumatic needle-free syringe which can adjust the liquid medicine jet speed and provide two jet speeds while ensuring a simple structure, and a method for using the same.

[0005] The present invention provides a pneumatic needle-free syringe, comprising a syringe body, a Laval trachea and a liquid medicine injection rate control mechanism;

[0006] One end of the Laval air tube is connected to the air chamber cavity of the syringe body, and the other end is used to connect to the air supply device;

[0007] The liquid medicine injection rate control mechanism includes a baffle that can adjust the throat opening of the Laval trachea and a controller for controlling the baffle to increase the throat opening at a set time after the injection starts.

[0008] Furthermore, the throat side wall is provided with a sliding groove, the baffle is slidably arranged in the sliding groove, and also includes a baffle adjustment mechanism for controlling the sliding position of the baffle.

[0009] Furthermore, the baffle adjustment mechanism includes a knob and a drive rod;

[0010] The knob is rotatably engaged with the outer wall of the syringe tube of the syringe body, a nut is fixedly provided inside the knob, the drive rod is slidably provided on the wall surface of the syringe tube, one end of the drive rod is threadably engaged with the nut, and the other end is connected to the baffle.

[0011] Furthermore, a scale is provided on the knob.

[0012] Furthermore, a sliding groove is provided at one end of the driving rod away from the nut, and one end of the baffle is slidably engaged with the sliding groove;

[0013] The controller includes an electromagnetic limiting mechanism and a baffle resetting mechanism;

[0014] A limiting groove is provided on the inner side wall of the slide groove, and the electromagnetic limiting mechanism includes a retractable electromagnetic limiting member provided in the limiting groove and a time controller for controlling the electromagnetic limiting member to retract into the limiting groove at a set time;

[0015] The baffle resetting mechanism includes an elastic member for driving the baffle to move toward the bottom of the chute.

[0016] Furthermore, two of the limiting grooves and the electromagnetic limiting members are symmetrically arranged on the side wall of the sliding groove.

[0017] Furthermore, the wall of the syringe tube of the syringe body is further provided with a slideway penetrating the outer wall to the throat;

[0018] The baffle reset mechanism also includes a reset control rod slidably arranged in the slide, one end of the reset control rod is fixedly connected to the baffle, and the other end extends out of the outer wall of the syringe tube of the syringe body, and the elastic member is arranged between the reset control rod and the inner wall of the slide.

[0019] Furthermore, the syringe body includes a syringe tube and an injection piston, the syringe tube includes an injection cavity and an air chamber cavity that are interconnected, the injection cavity is provided with a nozzle and a drug inlet hole at one end away from the air chamber cavity, the injection piston includes a piston head and a piston rod that are connected in sequence, the piston head is sealingly slidably arranged in the air chamber cavity, and the piston rod is sealingly slidably arranged in the injection cavity;

[0020] One end of the air chamber cavity away from the injection cavity is communicated with the Laval trachea.

[0021] Furthermore, the Laval air pipe includes an air chamber, a Laval nozzle and an air inlet pipe arranged in sequence;

[0022] The air chamber is provided with an opening toward the head of the syringe body, and the opening is communicated with the air chamber cavity of the syringe body;

[0023] The Laval nozzle and the outer wall of the air chamber are fixedly arranged in the air chamber cavity of the syringe body through a clamping block.

[0024] The present invention also provides a pneumatic needle-free syringe and a method for using the same. The method for using the pneumatic needle-free syringe comprises the following steps:

[0025] S1, before injection, the control baffle adjusts the throat of the Laval trachea to a set opening, and the controller sets the set time after the injection starts;

[0026] S2, when the injection starts, the controller starts timing, and the gas supply device continuously inputs gas at a constant pressure into the Laval tube. The gas pressure is amplified when passing through the Laval tube, increasing the pushing speed of the injection piston of the syringe body. The liquid in the injection chamber of the syringe body is ejected from the nozzle of the syringe body at a certain speed, causing the liquid to pierce the patient's skin;

[0027] After the timing of the controller ends, the baffle is adjusted to increase the throat opening, so that the speed at which the liquid medicine in the injection cavity of the syringe body is ejected from the nozzle of the syringe body is reduced, thereby preventing the liquid medicine from splashing and improving the utilization rate of the liquid medicine, while reducing the risk of injection pain and tissue damage caused by over-deep injection.

[0028] The pneumatic needle-free injector provided by the present invention has the beneficial effect of increasing the jet velocity while maintaining a consistent air supply pressure from the air supply device by providing a Laval airway. This reduces the air supply pressure requirement of the air supply device, thereby meeting user requirements while ensuring cost and safety. A baffle is provided to set the throat opening of the Laval airway. The baffle controls the pressure amplification capability of the Laval airway, allowing for adjustment of the initial jet velocity to suit the physique, injection site, and injection depth requirements of different recipients. This jet velocity adjustment does not require the air supply device to have air supply pressure adjustment capabilities, thus ensuring a simple and reliable structure. A controller is provided to control the baffle to increase the throat opening at a set time after the injection begins. The baffle controls the pressure amplification capability of the Laval airway, enabling a switch from a high-speed jet to a low-speed jet after a certain period of time. This prevents drug splashing, improves drug utilization, and reduces the risk of pain and tissue damage caused by over-deep injection. Furthermore, the switching process is quick and convenient, and the spray of the drug solution is continuous and coherent. Both the initial and reduced jet velocities can be adjusted by the baffle, providing greater adaptability. Compared with the dual-channel jet speed design of the Chinese patent "CN112412733A-Dual-channel needle-free injection device and method with controllable jet speed", on the one hand, it can solve the problem of waste of medicine caused by the need to fill both channels with medicine and the retention of medicine in the infusion tube after injection. On the other hand, the medicine of the present invention always flows in one injection cavity, and the medicine delivery is continuous. On the other hand, the initial jet speed and the jet speed after reduction of the present invention can be adjusted by the baffle, which has stronger adaptability and the overall structure is simpler and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Attachment Figure 1 It is a structural schematic diagram of the present invention;

[0030] Attachment Figure 2 This is a front view of the tail of the syringe body of the present invention;

[0031] Attachment Figure 3 It is a front cross-sectional view of the syringe body of the present invention;

[0032] Attachment Figure 4 For attachment Figure 3 A partial enlarged view of the middle baffle adjustment mechanism;

[0033] Attachment Figure 5 For attachment Figure 4 A partial enlarged view of the electromagnetic limit mechanism in the middle;

[0034] Attachment Figure 6 This is a circuit connection diagram of the time controller in the present invention;

[0035] Attachment Figure 7 It is a side sectional view of the baffle reset mechanism in the present invention;

[0036] Attachment Figure 8 Schematic diagram of the structure of the Laval trachea in the present invention.

[0037] In the figure, 1-syringe body; 11-syringe tube; 111-injection cavity; 112-air chamber cavity; 113-medicine inlet; 114-slide; 12-injection piston; 121-piston head; 122-piston rod; 13-nozzle; 2-Laval air pipe; 21-air chamber; 22-Laval nozzle; 221-throat; 2211-slide groove; 23-inlet pipe; 3-medicine liquid injection rate control mechanism; 31-baffle; 32-controller; 321-electromagnetic limit mechanism; 3211-electromagnetic limit Parts; 32111-electromagnet; 32112-limiting rod; 32113-spring; 3212-time controller; 32121-power supply; 32122-switch; 32123-time relay coil; 32124-normally open contact; 322-baffle reset mechanism; 3221-elastic part; 3222-reset control rod; 33-baffle adjustment mechanism; 331-knob; 332-driving rod; 3321-slide; 3322-limiting slot; 333-nut; 4-air supply device. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0041] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; it can mean mechanical connection, electrical connection, physical connection, or wireless communication connection; it can mean direct connection or indirect connection through an intermediate medium; it can mean internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0043] As attached Figure 1 -Attached Figure 8 As shown, the present invention provides a pneumatic needle-free syringe and a method of using the same, comprising a syringe body 1, a Laval trachea 2, and a liquid medicine injection rate control mechanism 3;

[0044] Among them, refer to the attached Figure 1 -Attached Figure 3 The syringe body 1 includes a syringe tube 11 and an injection piston 12. The syringe tube 11 includes an injection cavity 111 and an air chamber cavity 112 that are interconnected. The diameter of the injection cavity 111 is smaller than the diameter of the air chamber cavity 112, and the two are in a stepped hole structure. The injection cavity 111 is provided with a nozzle 13 and a medicine feed hole 113 at one end away from the air chamber cavity 112. The medicine feed hole 113 is used to add liquid medicine into the injection cavity 111, and the nozzle 13 is used to spray a liquid medicine jet. The injection piston 12 includes a piston head 121 and a piston rod 122 that are connected in sequence. The outer wall of the piston rod 122 is adapted to the air chamber cavity 112, and the piston rod 122 is away from the piston head 12 1 is adapted to the injection cavity 111 in size, that is, the piston head 121 and the piston rod 122 are in a stepped shaft structure, the piston head 121 is sealingly and slidably arranged in the air chamber cavity 112, and the piston rod 122 is sealingly and slidably arranged in the injection cavity 111. When the medicine inlet 113 is filled with liquid medicine to the upstream end of the injection cavity 111, the nozzle 13 is aimed at the user's skin, and gas of a set pressure is input into the air chamber cavity 112. The gas pushes the piston head 121 to move along the inner wall of the air chamber cavity 112, thereby driving the piston rod 122 to move. The piston rod 122 compresses the liquid medicine in the injection cavity 111, and the liquid medicine is ejected from the nozzle 13 at high speed, thereby realizing needle-free injection.

[0045] Among them, one end of the Laval air tube 2 is connected to the air chamber cavity 112 of the syringe body 1, and the other end is used to connect to the air supply device 4. The Laval air tube 2 can amplify the gas pressure output by the air supply device 4, thereby increasing the air pressure entering the air chamber cavity 112, thereby increasing the pushing speed of the injection piston 12, and increasing the jet speed of the liquid medicine ejected from the nozzle 13, thereby achieving a jet speed that can pierce the skin, thereby reducing the air supply pressure requirement of the air supply device 4. The present invention increases the jet speed on the basis of consistent air supply pressure of the air supply device 4 by adding a Laval air tube 2, thereby meeting the use requirements while ensuring cost and safety.

[0046] The liquid injection velocity control mechanism 3 includes a baffle 31 that can adjust the opening of the throat 221 of the Laval trachea 2, and a controller 32 for controlling the baffle 31 to increase the opening of the throat 221 at a set time after the injection begins. That is, before the injection begins, the baffle 31 can set the opening of the throat 221 of the Laval trachea 2 to adjust the initial jet velocity, achieving adjustable jet velocity. This adjustment method is different from adjusting the air supply pressure of the air supply device 4, and is simpler and more reliable, with lower adjustment costs and lower requirements for the air supply device 4. In actual use, the opening of the throat 221 of the Laval trachea 2 can be adjusted by the baffle 31 according to the physical condition of the injected person, the injection site, and the injection depth, thereby adjusting the jet velocity to achieve the most appropriate needle-free injection. After the injection set time, the controller 32 controls the baffle 31 to increase the opening of the throat 221, and utilizes the pressure amplification ability of the Laval trachea 2 to adjust the jet speed to achieve rapid reduction control, and achieve rapid switching between high-speed jet and low-speed jet. After a certain period of time, the high-speed jet is switched to the low-speed jet, which prevents the drug from splashing and improves the utilization rate of the drug, while reducing the risk of injection pain and tissue damage caused by over-deep injection.

[0047] In a specific embodiment, taking the gas supply device 4 as an example, the opening of the throat 221 corresponding to the liquid medicine jet velocity is as follows:

[0048]

[0049] As can be seen from the above table, by providing the Laval air pipe 2, the jet velocity can be significantly increased on the basis of the consistent air supply pressure of the air supply device 4, and the smaller the opening of the throat 221, the faster the liquid medicine jet velocity increases.

[0050] The pneumatic needle-free syringe provided by the present invention increases the jet velocity while maintaining the consistent air supply pressure of the air supply device 4 by providing a Laval airway 2. This reduces the air supply pressure requirement of the air supply device 4, thereby meeting usage requirements while ensuring cost and safety. Furthermore, a baffle 31 is provided to set the opening of the throat 221 of the Laval airway 2. The baffle 31 controls the pressure amplification capability of the Laval airway 2, thereby adjusting the initial jet velocity to suit the physique, injection site, and injection depth requirements of different injected individuals. This jet velocity adjustment does not require the air supply device 4 to have air supply pressure adjustment capabilities, thus ensuring a simple and reliable structure. Furthermore, a controller 32 is provided to control the baffle 31 to increase the opening of the throat 221 at a set time after the injection begins. The baffle 31 controls the pressure amplification capability of the Laval airway 2, enabling a switch from a high-speed jet to a low-speed jet after a certain period of time. This prevents drug splashing, improves drug utilization, and reduces the risk of injection pain and tissue damage caused by over-deep injection. Moreover, the switching process is fast and convenient, the injection of the liquid medicine is continuous and coherent, and the initial jet velocity and the jet velocity after reduction can be adjusted by the baffle 31, which has stronger adaptability. Compared with the dual-channel jet velocity design of the Chinese patent "CN112412733A-Dual-channel needle-free injection device and method with controllable jet velocity", on the one hand, it can solve the problem of liquid medicine waste caused by the retention of liquid medicine in the infusion tube 5 after injection when both channels need to be filled with liquid medicine. On the other hand, the liquid medicine of the present invention always flows in one injection cavity 111, and the liquid medicine delivery is continuous. On the other hand, the initial jet velocity and the jet velocity after reduction of the present invention can be adjusted by the baffle 31, which has stronger adaptability. Moreover, the overall structure is simpler and more reliable.

[0051] In one embodiment, refer to the attached Figure 3 and attached Figure 8 The sidewall of the throat 221 is provided with a sliding groove 2211, and the baffle 31 is slidably disposed within the sliding groove 2211. The device also includes a baffle adjustment mechanism 33 for controlling the sliding position of the baffle 31. Specifically, the baffle 31 longitudinally extends into or out of the throat 221 to adjust the opening of the throat 221, thereby reducing the area of ​​intrusion of the baffle 31 into the throat 221. In other embodiments, the baffle 31 may be hingedly disposed on the throat 221 in the form of a butterfly valve, and the opening of the throat 221 may be controlled by rotating the baffle 31.

[0052] In one embodiment, refer to the attached Figure 3 and attached Figure 4 , the baffle adjustment mechanism 33 includes a knob 331 and a driving rod 332;

[0053] The knob 331 is rotatably engaged with the outer wall of the syringe barrel 11 of the syringe body 1. A nut 333 is fixedly disposed within the knob 331. The drive rod 332 is slidably mounted on the wall of the syringe barrel 11. One end of the drive rod 332 is threadedly engaged with the nut 333, and the other end is connected to the baffle 31. With this arrangement, rotating the knob 331 on the outer wall of the syringe barrel 11 causes the nut 333 to rotate, thereby sliding the drive rod 332, and thus driving the baffle 31 along the sliding groove 2211 to adjust the opening of the throat 221. In this embodiment, the baffle 31 is manually adjusted, ensuring a simple, reliable structure and convenient adjustment.

[0054] In one embodiment, a scale is provided on the knob 331 to facilitate the operator to understand the opening of the throat 221.

[0055] In one embodiment, refer to the attached Figure 4 , Attachment Figure 5 and attached Figure 6 , the end of the driving rod 332 away from the nut 333 is provided with a sliding groove 3321, and one end of the baffle 31 is slidably engaged with the sliding groove 3321;

[0056] The controller 32 includes an electromagnetic limiting mechanism 321 and a baffle resetting mechanism 322;

[0057] The inner wall of the slide 3321 is provided with a limiting groove 3322. Preferably, the limiting groove 3322 and the slide 3321 are perpendicular to each other. The electromagnetic limiting mechanism 321 includes an electromagnetic limiting member 3211 which is retractably provided in the limiting groove 3322 and a time controller 3212 for controlling the electromagnetic limiting member 3211 to retract into the limiting groove 3322 at a set time. Specifically, the electromagnetic limiting member 3211 includes an electromagnet 32111 fixedly provided at the bottom of the limiting groove 3322 and a sliding member 3211 provided in the limiting groove 3322. The limiting rod 32112 in 322 is provided with a spring 32113 between the limiting rod 32112 and the electromagnet 32111. When the electromagnet 32111 is powered off, the spring 32113 pushes the limiting rod 32112 to extend into the chute 3321, limiting the position of the baffle 31. When the electromagnet 32111 is powered on, the electromagnet 32111 attracts the limiting rod 32112, and the limiting rod 32112 compresses the spring 32113 and retracts it into the limiting groove 3322, allowing the baffle 31 to move smoothly in the chute 3321. Figure 6The time controller 3212 includes a power supply 32121, a switch 32122 and a time relay. The time relay includes a time relay coil 32123 and a normally open contact 32124. The switch 32122 works synchronously with the gas supply start switch of the gas supply device 4. When the switch 32122 is turned on, the time relay coil 32123 is energized, and after the set time, the normally open contact 32124 is controlled to close, thereby energizing the electromagnet 32111.

[0058] The baffle plate resetting mechanism 322 includes an elastic member 3221 for driving the baffle plate 31 to move toward the bottom of the sliding groove 3321 .

[0059] During specific use, the electromagnet 32111 is powered off, the limit rod 32112 extends into the chute 3321, the baffle 31 is located at the end of the limit rod 32112 away from the bottom of the chute 3321, and the opening of the throat 221 is in a small opening state. When the switch 32122 and the gas supply start switch of the gas supply device 4 are turned on synchronously, the gas of the gas supply device 4 first enters the small opening throat 221, and the liquid medicine is jetted at high speed. Within the set time After that, the electromagnet 32111 is energized, and the electromagnet 32111 attracts the limit rod 32112 and retracts it into the limit groove 3322. Then the elastic member 3221 pulls the baffle 31 to the bottom of the slide groove 3321. At this time, the opening of the throat 221 is in a large opening state, and the medicine is jetted at a low speed until the injection piston 12 moves to the limit position to complete the injection. It should be noted that the high speed and low speed referred to in this embodiment are relative states.

[0060] In one embodiment, refer to the attached Figure 5 The limiting groove 3322 and the electromagnetic limiting member 3211 are symmetrically arranged on the side wall of the sliding groove 3321, thereby improving the limiting effect of the electromagnetic limiting member 3211 on the baffle 31.

[0061] In one embodiment, refer to the attached Figure 7 , the wall of the syringe tube 11 of the syringe body 1 is further provided with a slide 114 that penetrates the outer wall to the throat 221 , and the sliding direction of the slide 114 is consistent with the sliding direction of the slide groove 3321 ;

[0062] The baffle reset mechanism 322 also includes a reset control rod 3222 slidably arranged in the slide 114, one end of the reset control rod 3222 is fixedly connected to the baffle 31, and the other end extends out of the outer wall of the syringe tube 11 of the syringe body 1, and the elastic member 3221 is arranged between the reset control rod 3222 and the inner wall of the slide 114. In this embodiment, the position of the baffle 31 can be controlled by the reset control rod 3222 extending from the outer wall of the syringe tube 11. Specifically, after completing an injection, the time controller 3212 controls the electromagnet 32111 to cut off the power. At this time, since the baffle 31 is close to the bottom of the groove 3321, the extension of the limit rod 32112 is restricted. At this time, by operating the reset control rod 3222, the baffle 31 is driven to move toward the side of the throat 221 until the baffle 31 is located below the limit rod 32112. At this time, the limit rod 32112 receives the thrust of the spring 32113 and enters the groove 3321. Then the reset control rod 3222 is released, and the elastic member 3221 pushes the reset control rod 3222, so that the baffle 31 abuts against the limit rod 32112. In this embodiment, the baffle 31 can be reset by the baffle reset mechanism 322, thereby allowing the needle-free syringe to be reused. Furthermore, the elastic member 3221 ensures that the baffle 31 abuts the limiting rod 32112 or moves toward the bottom of the slide 3321, thereby ensuring the positional stability of the baffle 31. Furthermore, in this embodiment, when the baffle adjustment mechanism 33 adjusts the position of the baffle 31, it simultaneously drives the reset control rod 3222, the drive rod 332, and the electromagnetic limiting mechanism 321 to move. This ensures that, regardless of how the baffle adjustment mechanism 33 adjusts the baffle 31, when the electromagnetic limiting mechanism 321 releases the restriction on the baffle 31, the baffle 31 moves the same distance. This allows the degree of expansion of the throat 21 after a set time period to be determined. It is important to note that within the range of the distance the baffle adjustment mechanism 33 adjusts the baffle 31, the reset control rod 3222 can slide within the slide 114.

[0063] In one embodiment, refer to the attached Figure 8 The Laval air pipe 2 includes an air chamber 21, a Laval nozzle 22 and an air inlet pipe 23 arranged in sequence, wherein the throat 221 is the minimum diameter position of the Laval nozzle 22;

[0064] The air chamber 21 is provided with an opening toward the head of the syringe body 1 , and the opening is communicated with the air chamber cavity 112 of the syringe body 1 ;

[0065] The outer wall of the Laval nozzle 22 and the air chamber 21 are fixedly arranged in the air chamber cavity 112 of the syringe body 1 through a clamping block to ensure the stability and sealing of the connection.

[0066] The present invention also provides a pneumatic needle-free syringe and a method for using the same. The method for using the pneumatic needle-free syringe comprises the following steps:

[0067] S1, before injection, the control baffle 31 adjusts the throat 221 of the Laval trachea 2 to a set opening, and the controller 32 sets the set time after the injection starts;

[0068] S2, when the injection begins, the controller 32 starts timing (the time relay starts timing), and the gas supply device 4 continuously inputs gas at a constant pressure into the Laval tube 2. The gas pressure is amplified when passing through the Laval tube 2, increasing the pushing speed of the injection piston 12 of the syringe body 1. The liquid medicine in the injection chamber 111 of the syringe body 1 is ejected from the nozzle 13 of the syringe body 1 at a certain speed, causing the liquid medicine to pierce the patient's skin;

[0069] After the timing of the controller 32 ends, the baffle 31 is adjusted to increase the opening of the throat 221, so that the liquid in the injection cavity 111 of the syringe body 1 is ejected from the nozzle 13 of the syringe body 1 at a lower speed, thereby preventing the liquid from splashing and improving the utilization rate of the liquid. At the same time, it reduces the risk of injection pain and tissue damage caused by over-deep injection. The injection is completed when the injection piston 12 moves to the limit position.

[0070] The above description is merely an embodiment and does not limit the present invention in any way. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes, modifications, or modifications to the technical solution of the present invention into equivalent embodiments with equivalent changes using the technical content disclosed above. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A pneumatic needle-free syringe, characterized in that: It includes a syringe body (1), a Laval trachea (2) and a liquid injection rate control mechanism (3); One end of the Laval air tube (2) is connected to the air chamber cavity (112) of the syringe body (1), and the other end is used to connect to the air supply device (4); The liquid medicine injection rate control mechanism (3) includes a baffle (31) capable of adjusting the opening of the throat (221) of the Laval trachea (2) and a controller (32) for controlling the baffle (31) to increase the opening of the throat (221) at a set time after the start of injection; The side wall of the throat (221) is provided with a sliding groove (2211), the baffle (31) is slidably arranged in the sliding groove (2211), and further includes a baffle adjustment mechanism (33) for controlling the sliding position of the baffle (31); The baffle adjustment mechanism (33) includes a knob (331) and a driving rod (332); The knob (331) is rotatably engaged with the outer wall of the syringe tube (11) of the syringe body (1), a nut (333) is fixedly provided inside the knob (331), and the drive rod (332) is slidably provided on the wall surface of the syringe tube (11), one end of the drive rod (332) is threadably engaged with the nut (333), and the other end is connected to the baffle (31); A sliding groove (3321) is provided at one end of the driving rod (332) facing away from the nut (333), and one end of the baffle (31) is slidably engaged with the sliding groove (3321); The controller (32) includes an electromagnetic limiting mechanism (321) and a baffle resetting mechanism (322); A limiting groove (3322) is provided on the inner side wall of the sliding groove (3321), and the electromagnetic limiting mechanism (321) comprises a retractable electromagnetic limiting member (3211) provided in the limiting groove (3322) and a time controller (3212) for controlling the electromagnetic limiting member (3211) to retract into the limiting groove (3322) at a set time. The baffle plate resetting mechanism (322) comprises an elastic member (3221) for driving the baffle plate (31) to move toward the bottom of the sliding groove (3321).

2. The pneumatic needle-free injector according to claim 1, wherein: The knob (331) is provided with a scale.

3. The pneumatic needle-free injector according to claim 1, wherein: Two of the limiting grooves (3322) and the electromagnetic limiting members (3211) are symmetrically arranged on the side wall of the sliding groove (3321).

4. The pneumatic needle-free injector according to claim 1, wherein: The wall of the syringe tube (11) of the syringe body (1) is further provided with a slideway (114) penetrating the outer wall to the throat (221); The baffle reset mechanism (322) further includes a reset control rod (3222) slidably arranged in the slideway (114), one end of the reset control rod (3222) is fixedly connected to the baffle (31), and the other end extends out of the outer wall of the syringe tube (11) of the syringe body (1), and the elastic member (3221) is arranged between the reset control rod (3222) and the inner wall of the slideway (114).

5. The pneumatic needle-free injector according to any one of claims 1 to 4, wherein: The syringe body (1) comprises a syringe tube (11) and an injection piston (12), the syringe tube (11) comprises an injection cavity (111) and an air chamber cavity (112) which are interconnected, the injection cavity (111) is provided with a nozzle (13) and a medicine inlet (113) at one end away from the air chamber cavity (112), the injection piston (12) comprises a piston head (121) and a piston rod (122) which are connected in sequence, the piston head (121) is sealingly slidably arranged in the air chamber cavity (112), and the piston rod (122) is sealingly slidably arranged in the injection cavity (111); One end of the air chamber cavity (112) facing away from the injection cavity (111) is in communication with the Laval air tube (2).

6. The pneumatic needle-free injector according to any one of claims 1 to 4, wherein: The Laval air pipe (2) includes an air chamber (21), a Laval nozzle (22) and an air inlet pipe (23) which are arranged in sequence; The air chamber (21) is provided with an opening toward the head of the syringe body (1), and the opening is communicated with the air chamber cavity (112) of the syringe body (1); The Laval nozzle (22) and the outer wall of the air chamber (21) are fixedly arranged in the air chamber cavity (112) of the syringe body (1) via a clamping block.

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