Needleless syringe

Abstract

The present invention relates to a needleless syringe having a main body part and a nozzle part, wherein the main body part provides pulsed pressure to eject a drug as a microjet. A drug-receiving part filled with the drug comprises: a first reduced diameter part having a reduced inner diameter; a first enlarged diameter part having an increased inner diameter; a second reduced diameter part having a reduced inner diameter; and a third passage connected to a nozzle tip portion, wherein a check valve for making the drug flow in one direction is installed between the first enlarged diameter part and the second reduced diameter part to optimize the internal structure of a nozzle, thereby increasing the flow efficiency of the drug and reducing power consumption, and making it possible to optimize the amount of the drug supplied per injection.

Description

Needleless syringe

[0001] The present invention relates to a needleless syringe, and more particularly, to a needleless syringe capable of repeatedly injecting a drug at high speed without an injection needle.

[0002] A syringe is a device used to inject medication into the tissues of a living organism. It consists of a needle inserted into the body, a syringe barrel containing the medication, and a piston that reciprocates within the syringe barrel, pushing the medication into the needle. The needle has a hole to allow the medication to be injected.

[0003] However, in the case of diabetic patients who need to receive injections several times a day, they need to receive injections frequently even while receiving treatment at home rather than in a hospital. However, because of the pain when the needle penetrates the skin, it is difficult for them to inject themselves while receiving treatment at home rather than in a hospital.

[0004] Recently, research and development on needle-less syringes have been actively pursued to alleviate the fear of needles and prevent needle-borne infections.

[0005] However, since existing needleless syringes are designed to inject a certain amount of drug into only one part of the skin at a time, damage to skin tissue may occur.

[0006] In addition, because of the inconvenience of reloading after a single injection, there is a limitation in using it to evenly inject multiple drugs into a large area of ​​skin, such as in the field of skin beauty.

[0007] Accordingly, in order to solve these problems, the present inventors developed the needleless syringe disclosed in Patent Document 1. According to the needleless syringe disclosed in Patent Document 1, a piston that pressurizes and injects a drug is configured to repeatedly move back and forth using a power source such as a solenoid, thereby enabling a small amount of drug to be repeatedly injected at high speed and evenly injected into a wider area of ​​skin.

[0008] (Patent Document 1) Patent Document 1: Republic of Korea Patent No. 10-2088830 (March 9, 2020)

[0009] FIG. 15 is a drawing illustrating one embodiment of a needleless syringe disclosed in Patent Document 1.

[0010] As shown in Fig. 15, in the case of the needleless syringe disclosed in Patent Document 1, a solenoid coil (1a) is provided, and the piston (3) is moved forward by repeating the supply and cut-off of current to the solenoid coil (1a) at a preset cycle, and includes a current supply unit (not shown) and an elastic member that provides elasticity in the direction in which the piston (3) moves backward when the current supply to the current supply unit (not shown) is cut off.

[0011] Specifically, when the moving magnet (1b) advances a predetermined distance due to the magnetic force generated in the solenoid coil (1a), it collides with the piston head (3a) at the rear end of the piston (3), and the piston (3) advances due to the impact force at this time. Then, the springs (4a, 4b) are compressed by the advance of the piston (3), and when the current supply to the solenoid coil (1a) is stopped, the piston (3) retracts due to the compressive force of the springs (4a, 4b).

[0012] Meanwhile, a diaphragm (2b) is provided in front of the piston (3), and as the piston (3) moves backward, the diaphragm (2b) deforms, thereby reducing the pressure inside the valve chamber (7), and the drug is filled through the drug supply path (5a) extending from the drug charger (5) into the valve chamber (7) according to the pressure difference inside and outside the valve chamber (7). Then, as the piston (3) moves forward, the diaphragm (2b) deforms, thereby applying high pressure momentarily to the drug filled in the valve chamber (7), thereby causing the drug to be sprayed through the nozzle hole (2a) of the nozzle (2).

[0013] Meanwhile, a valve seat is formed in the middle of the valve chamber (7), and a check valve (8) is provided so that the drug flows only in one direction toward the nozzle portion (2a) through this valve seat. In the example shown in Fig. 8, the check valve (8) is provided with a ball pin and a spring that urges the ball pin toward the valve seat. As the piston (3) retracts, the diaphragm (2b) deforms and the drug is filled into the valve chamber (7), and the ball pin prevents outside air from entering the valve chamber (7) through the nozzle portion (2a) by urging the ball pin to the valve seat by the elastic force of the spring. In addition, as the piston (3) advances, the diaphragm (2b) deforms and the pressure inside the valve chamber (7) increases, and this pressure acts on the ball pin, causing the ball pin to overcome the elastic force of the spring and move forward, thereby allowing the drug filled inside the valve chamber (7) to be discharged to the outside through the nozzle portion (2a).

[0014] However, in the prior literature on needleless syringes, including Patent Document 1, the relationship between the shape of the internal flow path of the nozzle and the check valve (8) and the flow efficiency of the drug is not specifically considered at all.

[0015] The present invention has been devised to overcome the limitations of the above-mentioned prior art, and the purpose of the present invention is to provide a needleless syringe having a nozzle internal structure capable of optimizing flow efficiency.

[0016] In order to solve the above-described problem, the needleless syringe according to the present invention is a needleless syringe having a main body and a nozzle part, wherein the main body provides a pressure of a predetermined size to a drug contained in the nozzle part in the form of a pulse, and the nozzle part discharges the drug contained in the drug containing part in the form of a micro jet according to the pressure in the form of a pulse provided by the main body part, and the nozzle part includes a drug containing part filled with the drug and a nozzle tip part through which the drug filled in the drug containing part is discharged to the outside through a nozzle hole, and the drug containing part includes a first axial portion whose inner diameter decreases as it approaches the nozzle tip part, a first expanded portion which is in fluid communication with the first axial portion and whose inner diameter increases as it approaches the nozzle tip from the first axial portion, a second axial portion which is in fluid communication with the first expanded portion and whose inner diameter decreases as it approaches the nozzle tip from the first expanded portion, and a second axial portion. It is characterized in that it includes a third flow path for fluidly connecting the nozzle tip portion, and a check valve is provided in the space between the first expansion portion and the second axial reduction portion of the drug receiving portion to limit the flow path so that the drug in the drug receiving portion flows in one direction toward the nozzle tip portion.

[0017] Preferably, the maximum diameter of the first axial portion may be 3 mm or more and 40 mm or less.

[0018] Preferably, the minimum diameter of the first axial portion may be 0.5 mm or more and 20 mm or less.

[0019] Preferably, the distance between the main body side end of the second axial member and the nozzle tip side end of the third euro may be 0.5 mm or more and 50 mm or less.

[0020] Preferably, a first flow path having a constant inner diameter and fluidly communicating with the first axial portion and the first expanded portion may be provided between the first axial portion and the first expanded portion.

[0021] Preferably, a second flow path having a constant inner diameter and fluidly communicating with the first expansion portion and the second axial reduction portion may be provided between the first expansion portion and the second axial reduction portion.

[0022] Preferably, the nozzle tip portion may include a first nozzle tip portion flow path that is in fluid communication with the third flow path of the drug receiving portion and has an inner diameter that decreases from the drug receiving portion toward the nozzle hole of the nozzle tip portion, and a second nozzle tip portion flow path that has one end in fluid communication with the first flow path of the nozzle tip portion and the other end in fluid communication with the nozzle hole, and has an inner diameter that decreases from the first flow path of the nozzle tip portion toward the nozzle hole of the nozzle portion.

[0023] Preferably, the main body side end of the first axial reduction portion may further include a diaphragm configured to cover the main body side end and to change the pressure inside the first axial reduction portion by deforming according to a pulse-shaped pressure transmitted from the main body.

[0024] Preferably, the check valve may include a ball pin body in the shape of a rod, a ball pin head provided at one end of the ball pin body, and an elastic member installed to surround the ball pin body and pressurizing the ball pin head toward the inner wall surface of the first expanded portion.

[0025] Preferably, the ball pin head may have a peripheral edge portion configured to cover at least a portion of the ball pin body and the elastic member surrounding the ball pin body.

[0026] Preferably, the outer periphery of the ball pin head can be configured to be curved seamlessly from the tip of the ball pin head to the end of the peripheral edge.

[0027] Preferably, the other end of the ball pin body may be provided with a diametrically reduced portion whose outer diameter decreases toward the nozzle tip portion.

[0028] According to the present invention, a needleless syringe having an internal nozzle structure capable of optimizing flow efficiency such as drug discharge speed is provided, thereby reducing power consumed by the needleless syringe and optimizing the amount of drug supplied per injection.

[0029] In addition, according to the present invention, by alleviating the generation of vortex around the check valve, the flow of the drug passing through the check valve can be improved when the drug is injected.

[0030] Figure 1 is a configuration diagram of a needleless syringe according to the present invention.

[0031] Figure 2 is a configuration diagram of a needleless syringe according to the present invention, as shown in Figure 1.

[0032] Figure 2 is an enlarged partial view of the internal structure of the drug receiving portion and nozzle tip portion of the nozzle portion of the needleless syringe illustrated in Figure 1.

[0033] Figure 3 is an enlarged partial view of the drug-receiving portion of the internal structure of the needleless syringe illustrated in Figure 3.

[0034] FIG. 4 is a drawing showing a valve seat portion of a drug receiving portion according to a comparative example in contrast to the drug receiving portion of the nozzle portion of the needleless syringe shown in FIG. 1.

[0035] Figure 5 is an enlarged partial view of the nozzle tip of the nozzle portion of the needleless syringe illustrated in Figure 1.

[0036] Figure 6 is a graph showing the flow rate of a drug according to the maximum diameter (A) of the first axial section shown in Figure 2.

[0037] Figure 7 is a graph showing the flow rate of a drug according to the minimum diameter (B) of the first axial section shown in Figure 2.

[0038] Figure 8 is a graph showing the flow rate of a drug according to the length (C) of the third euro illustrated in Figure 2.

[0039] Figure 9 is a graph showing the velocity distribution of the drug within the drug receiving portion according to the maximum diameter (A) of the first axial portion illustrated in Figure 2.

[0040] Figure 10 is a graph showing the velocity distribution of the drug within the drug receiving portion according to the minimum diameter (B) of the first axial portion illustrated in Figure 2.

[0041] Figure 11 is a graph showing the velocity distribution of the drug within the drug receiving portion according to the length (C) shown in Figure 2.

[0042] Figure 12 is a graph showing the change in the speed of the drug per hour in the drug receiving portion according to the length (C) shown in Figure 2.

[0043] Figure 13 is a drawing for explaining the generation of vortex formed around the check valve of a conventional nozzle section.

[0044] Figure 14 is a drawing for explaining the flow of a drug formed around a check valve of a nozzle according to the present invention.

[0045] Figure 15 is a drawing showing the structure of a conventional needleless syringe.

[0046]

[0047] What each symbol represents is as follows:

[0048] 1: Body 1a: Solenoid coil

[0049] 2a: Nozzle section 2b: Diaphragm

[0050] 2c: Main Hall 3: Piston

[0051] 3a: Piston head 3b: Spring

[0052] 3c: Flange 4a: Fixed blocker

[0053] 4b: Length-adjusting blocker 5: Drug charger

[0054] 5a: Drug supply hole 6: Nozzle opening / closing valve

[0055] 7: Valve chamber 8: Check valve

[0056] 100: Main body 110: Solenoid coil

[0057] 120: Motion magnet 130: Piston

[0058] 200: Nozzle section 210: Drug receiving section

[0059] 220: Nozzle tip

[0060]

[0061] Hereinafter, a preferred embodiment of a needleless syringe according to the present invention will be described in detail with reference to the attached drawings.

[0062] FIG. 1 is a block diagram of a needleless syringe according to the present invention. As illustrated in FIG. 1, the needleless syringe according to the present invention includes a main body (100) and a nozzle part (200) having a drug containing part (210) and a nozzle tip part (220). In the example illustrated in FIG. 1, the main body (100) provides a pulse reciprocating motion of a moving magnet (120) provided inside the main body (100) by a driving force generated from a predetermined power source. In the embodiment illustrated in FIG. 1, the main body (100) is provided with a solenoid coil (110) on the outer periphery, and provides a pulse reciprocating motion of the moving magnet (120) by periodically changing the direction of the current applied to the solenoid coil (110). When the moving magnet (120) moves forward by the magnetic field formed by applying current to the solenoid coil (110), it collides with the piston (130) in front, and as the piston (130) moves forward due to this collision, a predetermined pressure is applied to the drug within the nozzle unit (200) described later. In addition, a spring (140) as an elastic member is provided on the inner wall of the main body unit (100) and the other end of the piston (130), so as to apply a force so that the piston (130) moves forward by a predetermined distance and then moves back to its original position. However, the example illustrated in FIG. 1 is only one preferred embodiment of the present invention, and there is no limitation as long as it has a configuration that can apply a predetermined pulse pressure to the drug filled inside the drug container (210) of the nozzle unit (200). For example, a configuration that forms power using compressed air or a spring and a motor instead of the solenoid coil may be used.

[0063] The nozzle unit (200) is composed of a hollow, cylindrical member, a drug receiving unit (210) that is filled with a drug therein and forms a path through which the drug is discharged to the outside of the nozzle, and a nozzle tip unit (220) that is configured to be in fluid communication with the drug receiving unit (210) and discharges the drug delivered from the drug receiving unit (210) to the outside of the nozzle unit (200). The nozzle unit (200) discharges the drug contained in the drug receiving unit (210) in the form of a micro jet from the nozzle tip unit (220) according to a pulse-shaped pressure provided by the main body (100). Preferably, the nozzle unit (200) is composed of a disposable part that is detachably connected to the main body (100), so that a user can easily configure a needle-free syringe by connecting the nozzle unit (200) filled with a suitable drug to the main body (100) when replacing the drug.

[0064] In addition, the drug receiving unit (210) may have a valve chamber structure as described above with reference to FIG. 14. That is, the drug receiving unit (210) has a valve chamber therein, and the drug solution is filled through a drug supply passage (218) extending into the valve chamber. In addition, as the piston (130) advances, the diaphragm (219) deforms, thereby instantly applying high pressure to the drug solution filled in the valve chamber, so that the drug solution is sprayed through the nozzle tip (220) of the nozzle unit (200). In addition, as illustrated in FIG. 14, a check valve may be provided inside the valve chamber so that a valve seat is formed in the middle, and the drug flows in one direction toward the nozzle tip (220) through the valve seat. A detailed description of the same matters as described with reference to the contents illustrated in FIG. 14 will be omitted below.

[0065] FIG. 2 is a drawing showing the inside of the drug receiving portion (210) and nozzle tip portion (220) of the nozzle portion of the needleless syringe shown in FIG. 1, and FIG. 3 is an enlarged partial view of the drug receiving portion (210) of the internal structure of the needleless syringe shown in FIG. 2.

[0066] Referring to the contents illustrated in FIGS. 2 and 3, the drug receiving unit (210) includes a first axially reduced portion (211) through which a drug introduced through a drug supply path (218) of the drug receiving unit (210) from an end adjacent to the main body (100) enters the inside thereof and the inner diameter thereof decreases as it approaches the nozzle tip portion (220), a first expanded portion (213) whose inner diameter increases as it approaches the nozzle tip portion from the first axially reduced portion (211), a second axially reduced portion (215) whose inner diameter decreases as it approaches the nozzle tip portion from the first expanded portion (213), and a third flow path (216) connecting the second axially reduced portion (215) and the nozzle tip portion (220). As illustrated in FIGS. 2 and 3, a check valve (237) is provided in the space (D) between the first axially reduced portion (211) and the second axially reduced portion (215) of the drug receiving portion (210) so that the drug flows in one direction toward the nozzle tip portion (220). In FIG. 2, the check valve (237) is shown in contact with the inner wall surface of the first expanded portion (213) to close the flow path, thereby preventing the drug from flowing back into the drug receiving portion. At this time, the first expanded portion (213) corresponds to a valve seat.

[0067] The first axial portion (211) forms an open end adjacent to the main body (100) and forms a fluid passage whose inner diameter gradually decreases as it approaches the nozzle tip (220). Preferably, a diaphragm is installed at the open end of the first axial portion (211) to cover the open end, so that the diaphragm deforms each time the piston (130) moves forward and backward, thereby changing the pressure inside the drug receiving portion (210), thereby adjusting the pressure applied to the drug. Through this, the supply of the drug through the drug supply passage (218) and the discharge of the drug to the nozzle tip (220) can be controlled. Preferably, the first axial portion (211) can be formed in a frusto-conical shape. As shown in Fig. 2, the maximum diameter (A) of the first axial portion (211) becomes the inner diameter of the open end, and the minimum diameter (B) of the first axial portion (211) becomes the inner diameter of the other end of the first axial portion (211).

[0068] The first expansion portion (213) is in fluid communication with the first axial expansion portion (211), and its inner diameter increases as it approaches the nozzle tip (220) from the first axial expansion portion (211). The first expansion portion (213) may be directly connected to the first axial expansion portion (211), or may be connected to the first axial expansion portion (211) through a first flow path (212) whose inner diameter becomes constant as it approaches the nozzle tip (220), as illustrated in FIG. 2.

[0069] The second axial member (215) is in fluid communication with the first expanded member (213), and its inner diameter decreases as it approaches the nozzle tip (220) from the first expanded member (213). The second axial member (215) may be directly connected to the first expanded member (213), or may be connected to the first expanded member (213) through a second flow path (214) having a constant inner diameter, as illustrated in FIG. 2.

[0070] The third flow path (216) is connected so that both ends of the flow path are in fluid communication with the second axial member (215) and the nozzle tip member (220), thereby fluidly connecting the two. As illustrated in FIG. 2, the third flow path (216) preferably has a tubular portion with a constant inner diameter. The length (C) illustrated in FIGS. 2 and 3 represents the distance between the end of the second axial member (215) on the main body (100) side and the end of the third flow path (216) on the nozzle tip (220) side.

[0071] When the piston (130) moves backwards through the driving source of the main body (100), the diaphragm (219) installed at the end (diameter (A) portion) of the first axial member (211) on the main body (100) side is deformed, thereby reducing the pressure inside the drug receiving portion (210), and depending on the pressure difference between the inside and outside of the drug receiving portion (210), the drug solution is filled into the drug receiving portion (210) through the drug supply path (218) from a drug charger (not shown). When the piston (130) is moved forward again through the driving source of the main body (100), the diaphragm (219) is deformed, thereby applying high pressure momentarily to the drug solution filled in the drug receiving portion (210), so that the drug solution is sequentially delivered through the first axial reduction portion (211), the first expanding portion (213), the second axial reduction portion (215), and the third flow path (216) toward the nozzle tip portion (220).

[0072] Meanwhile, as described below, in order to optimize flow efficiency, diameter A is 3 mm or more and 40 mm or less, more preferably 9 mm or more and 15 mm or less, diameter B is 0.5 mm or more and 20 mm or less, more preferably 2.5 mm or more and 4.0 mm or less, and length C is 0.5 mm or more and 50 mm or less, more preferably 6 mm or more and 12 mm or less.

[0073] Fig. 4 is a drawing showing a drug receiving portion according to a comparative example in contrast to the drug receiving portion of the nozzle portion of the needleless syringe shown in Fig. 1. In the case of the drug receiving portion of the needleless syringe shown in Fig. 4, it includes a reduced diameter portion (311) whose inner diameter decreases in the direction from the main body portion toward the nozzle tip portion, a first flow path (312) in fluid communication with the expanded diameter portion and having a constant inner diameter, an expanded diameter portion (312) in fluid communication with the first flow path (312) and having an inner diameter that increases in the direction toward the nozzle tip portion, and a second flow path (312) in fluid communication with the expanded diameter portion (312) and having a constant inner diameter.

[0074] Comparing the comparative example illustrated in FIG. 4 with the drug receiving portion (210) of the present invention illustrated in FIG. 3, in the comparative example illustrated in FIG. 4, the expanding portion (312) is directly connected to the second flow path (312) without a configuration corresponding to the second axial portion (215) of the drug receiving portion (210) of the present invention.

[0075] The following comparison table shows the test results measuring the drug discharge speed when the drug was discharged using a needleless syringe equipped with a nozzle part (200) according to a comparative example and an example of the present invention.

[0076] Case No.Inlet Diameter A[mm]Throat DiameterB [mm]Wake Region Length C [mm]Vmax [m / s]OriginalChamber9.72.7510.1374.6New Chamber12345678910111213141516171819202122232425269.79.79.79.79.79.79.79.79.7111111111111111111131 3131313131313132.753.33.82.753.33.82.753.33.82.753.33.82.753.33.82.753.33.82.753.33.82.753.33.82.7 53.33.810.110.110.166688810.110.110.166688810.110.110.1666888507.2483.5496.3499.0490.2481.9504.9495.2495.3516.0507.4510.8518.2511.0495.2529.1519.0507.6541.2532.3522.8522.8521.3509.9535.1526.7521.4

[0077] In Table 1, the results indicated as Original Chamber are test results using a needleless syringe equipped with a nozzle part having a drug receiving portion as shown in the comparative example of Fig. 4, and the results indicated as New Chamber are test results using a needleless syringe equipped with a nozzle part having a drug receiving portion as shown in the present invention example of Fig. 3, and test numbers No. 1 to No. 26 are results showing changes in drug discharge speed when diameter A, diameter B, and length C were changed, respectively.

[0078] As clearly shown in Table 1, it can be seen that the drug discharge speed of the present invention example of FIG. 3 is significantly higher than that of the comparative example of FIG. 4.

[0079] In addition, it can be confirmed that when the diameter A, diameter B, and length C of the drug receiving portion according to the present invention are within the preferred numerical range of the present invention described above, the drug discharging speed is at least 480 m / s or more.

[0080] Figure 5 is an enlarged partial view of the nozzle tip of the nozzle portion of the needleless syringe illustrated in Figure 1.

[0081] The nozzle tip portion (220) includes a nozzle tip portion first passage (230) having one end in fluid communication with the third passage (216) of the drug receiving portion (210) and an inner diameter that decreases as it goes from the drug receiving portion (210) to the nozzle hole (250) of the nozzle portion (200), and a nozzle tip portion second passage (240) having one end in fluid communication with the nozzle tip portion first passage (230), the other end in fluid communication with the nozzle hole (250), and an inner diameter that decreases as it goes from the nozzle tip portion first passage (230) to the nozzle hole (250) of the nozzle portion (200). As illustrated in FIG. 5, the rate at which the inner diameter decreases per unit length in the nozzle tip portion first passage (230) may be configured differently from the rate at which the inner diameter decreases per unit length in the nozzle tip portion second passage (240). Preferably, as illustrated in FIG. 4, the first flow path (230) of the nozzle tip portion may be configured as a multi-stage portion having different axial diameters per unit length. In addition, preferably, as illustrated in FIGS. 2 and 5, the inner diameter of the third flow path (216) may be configured to be larger than the inner diameter of the first flow path (230) of the nozzle tip portion, so that a step may be formed between the third flow path (216) and the first flow path (230) of the nozzle tip portion.

[0082] FIG. 6 is a graph showing the flow rate of a drug according to the maximum diameter (A) of the first axial portion shown in FIG. 3 in a needleless syringe having the drug receiving portion (210) shown in FIG. 3 and the nozzle tip portion (220) shown in FIG. 5, and FIG. 9 is a graph showing the velocity distribution of a drug within the drug receiving portion according to the maximum diameter (A) of the first axial portion shown in FIG. 3.

[0083] As shown in FIGS. 6 and 9, it can be seen that as the maximum diameter (A) increases, the drug discharge speed at the outlet increases.

[0084] In addition, Table 2 below shows the results of measuring the force applied to the drug at the measurement location (the minimum diameter portion (E) of the first axial portion) shown in Fig. 9. As can be seen in Table 2 below, it can be seen that the force applied to the drug at the measurement location increases by approximately 7.12% when the maximum diameter (A) is 13 mm compared to when the maximum diameter (A) is 9.7 mm. In this way, as the minimum diameter (A) increases, the force applied to the drug increases, and the flow rate of the drug becomes faster.

[0085] Diameter A (mm) 9.713 Measurement location Minimum diameter (E) Force (N) 0.489 0.524 Increase rate (%) 7.12

[0086] Fig. 7 is a graph showing the flow rate of a drug according to the minimum diameter (B) of the first axial portion shown in Fig. 3, and Fig. 10 is a graph showing the velocity distribution of a drug within a drug receiving portion according to the minimum diameter (B) of the first axial portion shown in Fig. 3. As shown in Figs. 7 and 10, it can be seen that as the minimum diameter (B) increases, the discharge rate of the drug at the outlet becomes slower.

[0087] In addition, Table 3 below shows the results of measuring the force applied to the drug at the measurement location (the minimum diameter portion (E) of the first axial portion) shown in Fig. 10. As can be seen in Table 3 below, it can be seen that the force applied to the drug at the measurement location increases by about 94.1% when the minimum diameter (B) is 2.75 mm compared to when the minimum diameter (B) is 3.8 mm. In this way, as the minimum diameter (B) decreases, the force applied to the drug increases, and the flow rate of the drug becomes faster.

[0088] Diameter B (mm) 3.8 2.75 Measurement location Minimum diameter (E) Force (N) 0.5 16 1.002 Increase rate (%) 94.1

[0089] Fig. 8 is a graph showing the flow rate of a drug according to the length (C) of the third flow path shown in Fig. 2, and Fig. 11 is a graph showing the velocity distribution of a drug within a drug receiving portion according to the length (C) shown in Fig. 2. As shown in Figs. 8 and 11, it can be seen that as the length (C) increases, the discharge rate of the drug at the outlet increases.

[0090] And, Fig. 12 is a graph showing the change in the speed of the drug per hour within the drug receiving portion according to the length (C) shown in Fig. 2. As shown in Fig. 12, it can be seen that the change in the speed per hour increases as the length (C) increases.

[0091] Fig. 13 is a drawing for explaining the generation of a vortex around a check valve of a conventional nozzle unit. In the example illustrated in Fig. 13, a check valve that allows only one-way flow of a drug within the drug-containing portion of the nozzle unit is formed of a ball pin, which is composed of a ball pin head (231) and a ball pin body (232), and an elastic member, such as a spring, for urging the ball pin head (231) of the ball pin toward a valve seat. Here, the valve seat may be, for example, an inner wall portion constituting the expanded portion illustrated in Fig. 3. As in the example illustrated in Fig. 13, in the case of a conventional check valve, a step portion is provided in the ball pin head (231) and the ball pin body (232), and the spring is configured such that its tip is settled on the step portion. In the case of such a configuration, as illustrated in Fig. 13, when the check valve is opened, a vortex is likely to be generated in the step portion between the ball pin head (231) and the ball pin body (232), in the flow of the drug along the outer periphery of the ball pin head (231). In addition, since the entire outer surface of the spring (240) is exposed to the flow of the drug, the possibility of eddy current generation increases. Therefore, the possibility of negatively affecting the flow rate of the drug passing through the check valve increases.

[0092] Figure 14 is a drawing for explaining the flow of a drug formed around a check valve of a nozzle according to the present invention.

[0093] In the present invention illustrated in FIG. 14, a check valve that allows only one-way flow of the drug within the drug receiving portion of the nozzle portion is formed of a ball pin body (232) and a ball pin head (260) provided at one end of the ball pin body (232), and an elastic member (240) such as a spring for urging the ball pin head (260) of the ball pin toward the valve seat. The ball pin body (232) may be a cylindrical rod-shaped member, and preferably, in order to suppress the generation of a vortex and secure the flow rate of the drug, may have a reduced-diameter portion whose outer diameter decreases toward the other end as illustrated in FIG. 14. The elastic member (240) is configured to surround the periphery of the ball pin body (232), one end of the elastic member (240) is connected to the ball pin head (260), and the other end of the elastic member (240) may be maintained, for example, on the inner wall of the second reduced-diameter portion (213) illustrated in FIG. 2. And, the valve seat may be, for example, an inner wall portion constituting the first expansion portion (213) illustrated in FIG. 2.

[0094] Unlike the conventional check valve illustrated in FIG. 12, in the case of the ball pin of the present invention, the ball pin head (260) is provided with a peripheral edge portion (260a) so as to cover at least a portion of the ball pin body (232) and one end of the spring (240) surrounding the ball pin body (232). Therefore, as illustrated in FIG. 13, when the check valve is opened, the flow of the drug along the outer periphery of the ball pin head (260) can be prevented from causing a vortex due to the contact between the exposed spring (240) and the flow of the drug. In addition, in the example illustrated in FIG. 12, the outer periphery of the ball pin head (260), including the peripheral edge portion (260a), is configured to continuously curve in the direction toward the ball pin body (232) without any steps such as seams or corners. Therefore, the flow of the drug along the ball pin head (260) can form a laminar flow along the surface of the ball pin head (260).

[0095] Accordingly, according to a preferred embodiment of the present invention illustrated in FIG. 12, when the flow between the drug receiving portion (210) illustrated in FIG. 3 and the nozzle tip portion (220) illustrated in FIG. 5 is controlled using a check valve, it is possible to suppress the occurrence of loss of drug flow occurring in the flow passing through the ball pin head constituting the check valve.

[0096] The present invention relates to a needleless syringe having a main body and a nozzle part, wherein the main body provides a pressure of a predetermined magnitude in the form of a pulse to a drug contained in the nozzle part, and the nozzle part discharges the drug contained in the drug container in the form of a microjet according to the pulse-shaped pressure provided from the main body, and the nozzle part includes a drug container filled with the drug and a nozzle tip part through which the drug filled in the drug container is discharged to the outside through a nozzle hole, and the drug container includes a first diameter part whose inner diameter decreases as it approaches the nozzle tip part, a first expanded diameter part which is in fluid communication with the first diameter part and whose inner diameter increases as it approaches the nozzle tip from the first diameter part, a second diameter part which is in fluid communication with the first expanded diameter part and whose inner diameter decreases as it approaches the nozzle tip from the first expanded diameter part, and a third flow path which fluidly connects the second diameter part and the nozzle tip part, and a check valve which restricts the flow path so that the drug in the drug container flows in one direction toward the nozzle tip part is characterized in that the space between the first expanded diameter part and the second diameter part of the drug container is provided. According to the present invention, a needleless syringe having an internal nozzle structure capable of optimizing flow efficiency such as drug discharge speed is provided, thereby reducing power consumed by the needleless syringe and optimizing the amount of drug supplied per injection.

[0097] According to the present invention, by providing a needleless syringe having an internal nozzle structure capable of optimizing flow efficiency, such as drug discharge speed, when a user injects a drug using the needleless syringe, the power consumed by the needleless syringe can be reduced and the amount of drug supplied per injection can be optimized. In addition, according to the present invention, by alleviating the generation of vortex around a check valve, the flow of the drug passing through the check valve can be improved when the drug is injected.

Claims

1. In a needleless syringe having a main body and a nozzle, The above main body part provides a pressure of a predetermined size in the form of a pulse to the drug contained in the nozzle part, The nozzle part discharges the drug contained in the drug receiving part in the form of a micro jet according to the pulse-shaped pressure provided from the main body part, and the nozzle part includes a drug receiving part in which the drug is filled and a nozzle tip part in which the drug filled in the drug receiving part is discharged to the outside through a nozzle hole. The drug receiving portion includes a first axial portion whose inner diameter decreases as it approaches the nozzle tip portion, a first expanded portion whose inner diameter is in fluid communication with the first axial portion and whose inner diameter increases as it approaches the nozzle tip portion from the first axial portion, a second axial portion whose inner diameter is in fluid communication with the first expanded portion and whose inner diameter decreases as it approaches the nozzle tip portion from the first expanded portion, and a third flow path which fluidly connects the second axial portion and the nozzle tip portion. A needleless syringe characterized in that a check valve is provided in the space between the first expansion portion and the second axial portion of the drug receiving portion to limit the flow of the drug in the drug receiving portion in one direction toward the nozzle tip portion.

2. In claim 1, A needleless syringe, wherein the maximum diameter of the first axial portion is 3 mm or more and 40 mm or less.

3. In claim 1, A needleless syringe, wherein the minimum diameter of the first axial portion is 0.5 mm or more and 20 mm or less.

4. In claim 1, A needleless syringe, wherein the distance between the main body end of the second axial member and the nozzle tip end of the third euro is 0.5 mm or more and 50 mm or less.

5. In claim 1, A needleless syringe, wherein a first flow path having a constant inner diameter is provided between the first axial portion and the first expanded portion, and is in fluid communication with the first axial portion and the first expanded portion, respectively.

6. In claim 1, A needleless syringe, wherein a second passage having a constant inner diameter is provided between the first expansion portion and the second axial reduction portion, and is in fluid communication with the first expansion portion and the second axial reduction portion, respectively.

7. In claim 1, A needleless syringe, wherein the nozzle tip portion is in fluid communication with the third flow path of the drug receiving portion, and includes a nozzle tip portion first flow path whose inner diameter decreases as it goes from the drug receiving portion to the nozzle hole of the nozzle tip portion, and a nozzle tip portion second flow path whose one end is in fluid communication with the first flow path of the nozzle tip portion, the other end is in fluid communication with the nozzle hole, and whose inner diameter decreases as it goes from the first flow path of the nozzle tip portion to the nozzle hole of the nozzle portion.

8. In claim 1, A needleless syringe further comprising a diaphragm configured to cover the main body end of the first axial section and configured to change the pressure inside the first axial section by deforming according to the pulse-shaped pressure transmitted from the main body.

9. In claim 1, A needleless syringe, wherein the check valve comprises a rod-shaped ball pin body, a ball pin head provided at one end of the ball pin body, and an elastic member installed to surround the ball pin body and pressurizing the ball pin head toward the inner wall surface of the first expanded portion.

10. In claim 9, A needleless syringe, wherein the ball pin head has a peripheral edge portion configured to cover at least a portion of the ball pin body and the elastic member surrounding the ball pin body.

11. In claim 10, A needleless syringe, wherein the outer circumference of the ball pin head is configured to be curved seamlessly from the tip of the ball pin head to the end of the peripheral edge.

12. In claim 9, A needleless syringe, wherein the other end of the ball pin body is provided with a diaphragm portion whose outer diameter decreases toward the nozzle tip portion.

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