Syringe plunger rod, syringe barrel and syringe
By designing an elastic sealing plug with concentric steps and a syringe with a press-fitted hollow needle, the existing syringe has solved the problems of high cost, large residues and infectious disease transmission, and the use of low-cost, safe and efficient syringe is achieved.
Patent Information
- Application Number
- CN202380081977.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-11-29
- Filing Date
- 2023-11-10
- Publication Date
- 2025-07-04
AI Technical Summary
Existing syringes have problems such as high manufacturing costs, large drug residues, inability to completely clear, and repeated use leads to the spread of infectious diseases.
A syringe is designed including a sealing plug and a syringe barrel. The sealing plug is made of elastic material and has concentric steps on the distal surface for sealing engagement with the syringe barrel. The hollow needle is installed by press fit to reduce drug residues and infectious disease transmission.
It realizes low-cost manufacturing, reduces drug residues, prevents reuse, and improves the safety and efficiency of the syringe.
Smart Images
Figure CN120265344A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a syringe plunger rod, a syringe barrel, and a syringe including the syringe plunger rod and the syringe barrel. Background Art
[0002] Injection is one of the most common healthcare procedures, with up to 22 billion injections being administered globally each year. In 2021, the large-scale vaccination against the COVID-19 pandemic will require even more syringes for injection.
[0003] Syringes known in the art can be pre-filled syringes, which are already filled with drugs / vaccines at the time of delivery, or empty traditional syringes that are filled with the drug to be administered to the patient on-site. Pre-filled syringes are made of glass or polymer materials. However, their manufacturing process is not cost-effective. In addition, glass syringes are even more expensive than polymer syringes.
[0004] Traditional syringes are used with hypodermic needles, which are connected to the syringe tip before use. The manufacturing cost of traditional syringes is lower than that of pre-filled syringes, but they cannot completely empty the drug in the syringe barrel / hypodermic needle, that is, a certain amount of residual drug is lost with each injection. This results in the loss of drugs containing expensive active ingredients. Vials containing drugs are usually filled with 20% of the remaining drug to make up for the loss of drug in the dead space of the syringe. In addition, due to the presence of dead space in traditional syringes, air needs to be expelled before injection (the air present in the dead space before the needle is filled) to prevent air embolism. This is a time-consuming and drug-wasting process.
[0005] In addition, using the same syringe to inject multiple people multiple times can lead to the spread of several infectious diseases. It is estimated that more than 2 million patients and users are infected with serious blood-borne diseases, such as HIV, hepatitis B, and hepatitis C, each year due to the misuse of syringes. Most of these injections are carried out using commercially available traditional syringes or pre-filled traditional syringes. As early as 2015, the World Health Organization (WHO) set a deadline that by 2020, all syringes globally should be replaced with so-called "smart syringes", such as auto-disable (AD) syringes. Smart syringes can prevent the reuse of syringes, thus reducing the spread of the above-mentioned infectious diseases.
[0006] However, the commercially available smart syringes also have the above-mentioned several disadvantages. For example, these syringes cannot completely empty the drug in the syringe barrel.
[0007] Therefore, there is a need for an improved syringe that is inexpensive to manufacture and can reduce the residual volume of the drug in the barrel after injection. Summary of the Invention
[0008] In view of this, the present invention preferably attempts to alleviate, mitigate or eliminate one or more of the above-mentioned defects and disadvantages in the prior art, either alone or in any combination, and solves at least the above problems by providing a syringe plunger rod extending along a longitudinal central axis, the syringe plunger rod comprising:
[0009] A distal plunger top having a sealing plug for sealing engagement with a syringe barrel; a proximal elongated rod including a proximal end adapted to receive an applied force along the longitudinal central axis; wherein the sealing plug is made of an elastic material, and wherein the distal surface of the sealing plug includes a plurality of concentric steps, and the concentric steps rise laterally.
[0010] The present invention also provides a syringe barrel extending along a longitudinal central axis and comprising: a barrel defining a volume for containing a drug, the barrel having a distal plunger socket wall and a tubular wall extending proximally from the distal plunger socket wall; a needle hub extending distally from the barrel; and a hollow needle extending distally from the needle hub, wherein the needle hub is provided with a longitudinal needle press-fit channel flush with the distal plunger socket wall such that the press-fit channel extends proximally into the volume, and wherein the hollow needle is press-fitted into the press-fit channel.
[0011] The present invention also provides a syringe comprising such a syringe plunger rod and a syringe barrel.
[0012] Further advantages will be apparent from the detailed description and the appended dependent claims. Description of the Drawings
[0013] These and other aspects, features and advantages of the present invention will become clearer and more distinct by combining the following description of embodiments of the present invention with the accompanying drawings. Among them:
[0014] Figure 1 Is a longitudinal sectional view of the syringe;
[0015] Figure 2 Is a detail view of the syringe according to the present invention and a sectional view of its use position. Detailed Description
[0016] Embodiments of the present invention will be described in more detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the present invention. However, the present invention can be implemented in many different forms and should not be construed as limited to the embodiments described herein. On the contrary, these embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.
[0017] The embodiments do not limit the present invention, which is only limited by the appended claims. In addition, the terms used in the detailed description of the specific embodiments shown in the drawings are not used to limit the present invention.
[0018] Please refer to Figure 1 , a syringe plunger rod 100 is disclosed. The syringe plunger rod 100 extends along a longitudinal central axis A. The syringe plunger rod 100 includes a distal plunger top 101. The distal plunger top 101 includes a sealing plug 102. In use, the sealing plug 102 seals a syringe barrel 200 to form a syringe 300. A slender rod 103 is provided at the proximal end of the sealing plug 102. A push plate 104 is provided at the proximal end of the slender rod 103. The push plate 104 extends substantially transversely to the longitudinal central axis A. The push plate 104 is adapted to receive a force applied along the axis A during use, such that the syringe plunger rod 100 is displaced relative to the barrel 200.
[0019] According to Figure 2 , the present invention also provides a syringe barrel 200. The syringe barrel 200 extends along the longitudinal central axis A. The syringe barrel 200 includes a barrel 201 defining a volume V adapted to contain a drug. The barrel 201 has a distal plunger socket wall 202 and a tubular wall 203 extending proximally from the distal plunger socket wall 202. A needle seat 204 extends distally from the barrel 201. A hollow needle 205 extends distally from the needle seat 204. The needle seat 204 is provided with a longitudinal needle press - fit channel 206. The press - fit channel 206 is flush with the distal plunger socket wall 202, such that the press - fit channel 206 extends proximally into the volume V, such that the press - fit channel 206 extends into the volume V. The hollow needle 205 is press - fit into the press - fit channel 206. The wall thickness of the needle seat 204 around the press - fit channel 206 is preferably 0.5 to 1.5 millimeters, which provides tensile strength and flexibility during the needle installation process. In addition, the length of the press - fit channel 206 in the longitudinal direction is preferably 1.5 to 4.5 millimeters. The relatively thin thickness enhances the seal between the hollow needle 205 and the needle seat 204 and reduces irregularities and weak points therein. In addition, it minimizes the resistance during the sealing process and provides the maximum contact diameter between the hollow needle 205 and the needle seat 204. In addition, it also provides stretchability of the needle seat wall, which facilitates and helps to press - fit the hollow needle 205 into the needle seat 204.
[0020] The sealing plug 102 is made of an elastic material, and a sealing plug distal surface 105 is provided at the distal end of the sealing plug 102. The sealing plug distal surface 105 includes a plurality of concentric steps 106. As used herein, the term "concentric" refers to an extension around the central axis A and does not necessarily have the same step length, the same step height, exactly the same roundness, exactly the same center, circumference, etc., but these cases are not excluded. In Figure 2In the illustrated embodiment, this means that the different steps 106 are provided at different radial distances from the central axis A and extend around the central axis A.
[0021] In Figure 2 the illustrated embodiment, the number of concentric steps is five. However, this number can vary depending on the size of the syringe into which the syringe plunger rod 100 is installed and / or the drug to be injected. The number of steps 106 can be from 2 to 50, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10.
[0022] The steps 106 climb laterally, i.e., towards the circumference of the seal plug 102. When the syringe plunger rod 100 is displaced relative to the barrel 200, the distal surface 105 of the final seal plug will abut against the distal plunger socket wall 202 of the barrel 200. When the syringe plunger rod 100 is displaced relative to the barrel 200, the seal plug 102 slides against the tubular wall 203 of the barrel 200. Since the steps 106 climb laterally, the outermost step 106 will first abut against the distal plunger socket wall 202, thereby squeezing the liquid to be injected towards the center. In this way, the last portion of the drug to be injected, such as a vaccine or a viscous drug, is pushed from the periphery to the center of the needle passage. Due to the elasticity of the seal plug 102, when an additional force is applied in the distal direction, the seal plug 102 will deform, so that the central step portion of the outermost step 106 will be displaced relative to the barrel 200 to abut against the distal plunger socket wall 202. In this way, the liquid to be injected is further pushed towards the center. For each step 106, the same relative movement relative to the barrel 200 is repeated to push the liquid towards the center and into the hollow needle 205 of the barrel 200. In this way, the amount of air trapped in the interface between the seal plug 102 and the plunger socket wall 202 can be reduced.
[0023] The height of each step can be from 0.01 mm to 1 mm. The number of steps 106 can be from 2 to 50. The parameters for adjusting the step height and the number of steps can be the inner diameter of the barrel 200 and the modulus of elasticity E of the seal plug 102. The width of the steps 106 can also vary.
[0024] A central platform 107 is provided at the central position of the distal surface 105 of the seal plug (i.e., below the hollow needle 205), and the concentric steps extend laterally from this platform. Therefore, the central platform 107 is located directly below the proximal end of the hollow needle 205. In this way, the configuration of the distal surface 105 of the seal plug is such that the amount of liquid to be injected remaining in the barrel 200 is minimized, because the central platform 107 can be flush with the proximal end of the hollow needle 205.
[0025] The distal surface 105 of the seal plug is generally conical, such that the most lateral concentric step is disposed near the distal point of the seal plug 102, such as the platform 107. This further helps to push the fluid to be injected into the hollow needle 205, since the distal injection force generates a distal force component.
[0026] Returning to the syringe barrel 200, the needle hub 204 includes a distal needle hub opening 207 that tapers in the proximal direction towards the longitudinal central axis A and the center of the distal needle hub opening 207. The hollow needle 205 has a proximal needle tip 208 that has an external taper or is rounded and tapers / rounds towards the longitudinal central axis A. The proximal needle tip 208 of the hollow needle 205 is substantially flush with the distal plunger socket wall 202. The proximal 208 of the hollow needle 205 is engaged within the needle hub 204. When the hollow needle 205 is moved into the press-fit channel 206 to attach the hollow needle 205 to the needle hub 204, the internal taper of the needle hub 204 guides the hollow needle 205 into the needle hub 204. Additionally, the taper reduces the friction between the hollow needle 205 and the needle hub 204, facilitating the connection of the hollow needle 205. If the internal taper of the needle hub 204 and the external taper of the hollow needle 205 were straight instead of tapered, it would be difficult for the proximal needle tip 208 to match the needle hub opening 207. Further, high pressure would build up between the outer surface of the proximal needle tip 208 and the needle hub 204 (such as the press-fit channel 206). The rounded external taper on the proximal needle tip 208 is advantageous as it reduces the risk of the hollow needle 205 peeling material from the needle hub 204 during installation. Sharp edges could scratch the needle hub 204, causing plastic particles to potentially flake off the needle hub 204 and mix with the drug being injected through the hollow needle 205. The needle hub opening 207 and the remainder of the needle hub 204 are injection molded or machined from the same mandrel to form the needle hub 204 with the internal taper. Thus, when the hollow 205 is inserted into the needle hub opening 207, no shoulders or other obstructions are encountered.
[0027] Since the hollow needle 205 is press - fit into the needle hub 204, no adhesive or glue is required to attach the hollow needle 205 to the needle hub 204. In pre - filled syringes known in the art, whether glass syringes or polymer syringes, it is very common to use adhesives to connect the needle to the syringe. In the injection - molding process of forming a polymer syringe, the needle can be cast into the syringe barrel. However, compared with the press - fit mounting process for syringes described herein, this is not a cost - effective needle integration technique. In addition, all types of adhesives (such as epoxy resins or glues) used in syringes pose quality risks. The viscous adhesive may enter the drug / vaccine flow area inside the syringe, thus damaging the syringe. The press - fit eliminates the need for adhesives. In addition, there is always a risk that once the injection needle is connected, it may leak or fall off during injection, for example, if a Luer - slip syringe with an injection needle is used. Finally, even with a smart syringe with a hypodermic needle, it is possible to disassemble the hypodermic needle after injection and reuse it with another syringe barrel, leading to the spread of infectious diseases. The syringe barrel 200 described herein can alleviate this problem because the hollow needle 205 is securely connected to the needle hub 204.
[0028] After the hollow needle 205 is press - fit into the press - fit channel 206, preferably the proximal end 208 of the needle is at the proximal - distal level with the plunger socket wall 202 to minimize dead space in the syringe 300. The inner diameter of the hollow needle 205 can be about 0.15 to 0.2 millimeters.
[0029] The syringe barrel 200 is made of a polymer material, preferably a plastic selected from cycloolefin polymer (COP), cycloolefin copolymer (COC), or polypropylene (PP). These polymers are particularly preferred because they facilitate the press - fit of the hollow needle 205 into the needle hub 204 due to their beneficial tensile strength properties.
[0030] A needle cap (not shown) can be set onto the cap flange 209, which extends distally and is provided on the side of the needle hub 204. The cap flange 209 is configured to surround the cylinder of the needle hub 204 and is configured such that the needle cap can be slidably engaged onto the cap flange 209. The needle cap protects the user from the hollow needle 205. The cap flange 209 separated from the needle hub 204 allows the size of the needle cap to be separate from the size of the needle hub 104 and vice versa. In addition, the cap flange 209 can be made thinner, thus increasing flexibility and facilitating the setting of the needle cap onto the cap flange 209.
[0031] The hollow needle 205 has a plurality of circumferential grooves 210, such as radial grooves, on its outer surface, and when the hollow needle 205 is in place within the needle hub 204, these grooves face the inner cavity wall of the needle hub 204. The circumferential grooves 210 increase the connection strength between the hollow needle 205 and the needle hub 204. Such a technique is simple and inexpensive and can firmly fix the hollow needle 205 within the needle 204. Each circumferential recess 210 has a V-shaped or U-shaped cross-section, and once the hollow needle 205 is press-fitted into the needle hub 204, the edges of the grooves 210 engage with the polymeric material of the needle hub 204. This is because all polymeric materials have limited creep properties during the press-fitting process. When subjected to press-fitting, pressure, strain, and tension are applied to the solid polymeric needle hub 204, and the needle hub 204 begins to cold flow, and the circumferential grooves 210 with edges can engage with the needle hub 204. Thus, enhanced adhesion of the hollow needle 205 within the needle hub 204 is achieved.
[0032] The needle hub opening 207 can be melted after the hollow needle 205 is inserted, so as to abut against the outer surface of the hollow needle 205. Such a technique allows for reducing the difficulty of press-fitting and can also be used with needles that do not have any circumferential grooves 210. The melted needle hub opening 207, together with the circumferential grooves 210, provides a more secure and firm connection for the hollow needle 205 within the needle hub 204.
[0033] The syringe barrel 200 has a volume V for accommodating a drug, vaccine, or any other type of liquid medicine or solution to be injected into a patient. The drug can be in liquid form for injection into a patient or user.
[0034] Figure 1 The plunger rod 100 is disposed within the syringe barrel 200. The plunger rod 100 extends along the tubular wall 203 and the axis A.
[0035] The sealing plug 102 is adapted to engage fluid-tightly with the tubular wall 203 of the syringe barrel 200. By engaging fluid-tightly with the tubular wall 203 of the syringe barrel 200, leakage of the drug or liquid contained within the syringe barrel 200 from any other direction than through the hollow needle 205 can be prevented from the syringe 300.
[0036] Figure 2 a to Figure 2 f illustrate the operation of the syringe 300, which includes Figure 1 the plunger rod 100 and the syringe barrel 200 therein. Figure 2 a to Figure 2 f illustrate a sectional view of the syringe 100 in its use position.
[0037] In Figure 2In a, the plunger rod 100 is pushed towards the distal end. The sealing plug 102 moves along the tubular wall 203 of the syringe barrel 200. The distal surface 105 of the sealing plug has not yet abutted against the plunger socket wall 202.
[0038] In Figure 2 In b, the periphery of the distal surface 105 of the sealing plug 102 (i.e., the outermost step 106) abuts against the outermost part of the plunger socket wall. Thus, the fluid / drug within the volume V of the syringe 100 is forced towards the center of the outermost step 106.
[0039] In Figure 2 In c, compared to the position in Figure 2 b, the plunger rod 100 is further advanced towards the distal end, and due to the elastic properties of the sealing plug 102, the sealing plug 102 deforms to conform to the shape of the plunger socket wall 202. Thus, the fluid / drug contained within the volume V of the syringe 100 is forced towards the center of the step 106, which is the second step starting from the periphery.
[0040] In Figure 2 In d, compared to the position in Figure 2 c, the plunger rod 100 advances further distally, and due to the elastic properties of the sealing plug 102, the sealing plug 102 further deforms to conform to the shape of the plunger socket wall 202. Thus, the fluid / drug contained within the volume V of the syringe 100 is forced towards the center of the step 106, which is the third step starting from the periphery.
[0041] In Figure 2 In e, compared to the position in Figure 2 d, the plunger rod 100 is again advanced distally, and due to the elastic properties of the sealing plug 102, the sealing plug 102 further deforms to conform to the shape of the plunger socket wall 202. Thus, the fluid / drug contained within the volume V of the syringe 100 is forced towards the center of the step 106, which is the fourth step starting from the periphery.
[0042] In Figure 2 In f, compared to the position in Figure 2 d, the plunger rod 100 is further advanced towards the distal end, and due to the elastic properties of the sealing plug 102, the sealing plug 102 further deforms to conform to the shape of the plunger socket wall 202. Thus, the fluid / drug contained within the volume V of the syringe 100 is forced towards the center of the step 106, which is the fifth step starting from the periphery. At this position, the central platform 107 closes the press - fit channel 206, emptying the entire volume V of the barrel 200.
[0043] The sealing plug 102 is made of an elastic flexible material, preferably a polymeric material selected from thermoplastic elastomers or natural or synthetic rubber materials. The greater the force applied in the distal direction, the greater the portion of the distal surface 105 of the sealing plug that contacts the plunger socket wall 202.
[0044] In addition, the present invention has been mainly described with reference to several embodiments. However, those skilled in the art should understand that, in addition to the above embodiments, other embodiments may also fall within the scope defined by the appended claims of the present invention.
[0045] In the claims, the terms "comprising / including" do not exclude the presence of other components or steps. In addition, although listed separately, multiple devices, components, or method steps may be implemented by, for example, a single unit or processor. In addition, although the various features may be included in different claims, these features may be advantageously combined together, and being included in different claims does not mean that the combination of features is not feasible and / or not advantageous. In addition, a singular reference does not exclude a plural reference. The terms "a", "an", "first", "second", etc. used herein do not exclude a plural reference. The reference signs in the claims are provided only by way of illustration and should not be construed as limiting the scope of the claims in any way.
Claims
1. A syringe plunger rod (100) extending along a longitudinal central axis (A), characterized in that: The syringe plunger rod includes: A distal sealing plug (102) for sealing engagement with a syringe barrel (200); A proximal elongated rod (103) including a proximal end (104) adapted to withstand an applied force along the longitudinal axis (A); Wherein, the sealing plug (102) is made of an elastic material, and a distal surface (105) of the sealing plug includes a plurality of concentric steps (106), wherein the plurality of concentric steps (106) climb laterally.
2. The syringe plunger rod (100) according to claim 1, characterized in that: The number of the plurality of concentric steps (106) is two, three, four, five, six, seven, eight, nine or ten.
3. The syringe plunger rod (100) according to claim 1 or 2, characterized in that: The distal surface (105) of the sealing plug is provided with a central platform (107), and the plurality of concentric steps (106) climb laterally from the central platform.
4. The syringe plunger rod (100) as described in any one of the preceding claims, characterized in that: The distal surface (105) of the sealing plug is generally conical, such that the most lateral concentric step (106) is disposed proximal to a distal point of the sealing plug (102).
5. A syringe barrel (200) extending along a longitudinal central axis (A), characterized in that: The syringe barrel includes: A barrel (201) defining a volume (V) for containing a drug, the barrel (201) having a distal plunger socket wall (202) and a tubular wall (203) extending proximally from the distal plunger socket wall (202); A needle seat (204) extending distally from the barrel (201); A hollow needle (205) extending distally from the needle seat (204); Wherein, the needle seat (204) is provided with a longitudinal needle press-fit channel (206), wherein the press-fit channel (206) is flush with the distal plunger socket wall (202), such that the press-fit channel (206) extends proximally into the volume (V); Wherein, the hollow needle (205) is press-fitted into the press-fit channel (206).
6. The syringe barrel (200) according to claim 5, characterized in that: The needle seat (204) includes a needle seat opening (207) having an internal tapered radius that tapers towards the longitudinal central axis (A) and a center of the needle seat opening (207).
7. The syringe barrel (200) according to any one of claims 5 or 6, characterized in that: The hollow needle (205) has a proximal end of the needle tip (208) having an external tapered radius that tapers outwardly, the external tapered radius tapering towards the longitudinal central axis (A) and a center of a perpendicular cross-section of the hollow needle (205).
8. The syringe barrel (200) according to any one of claims 5 to 7, characterized in that: The syringe barrel (200) is made of a polymer material, preferably made of a plastic selected from cycloolefin polymer (COP), cycloolefin copolymer (COC) or polypropylene (PP).
9. The syringe barrel (200) according to any one of claims 5 to 8, characterized in that: The proximal end of the needle tip (208) of the hollow needle (205) is substantially flush with the distal plunger socket wall (202).
10. A syringe (300), characterized in that: Comprising the syringe plunger rod (100) according to any one of claims 1 to 4 and the syringe barrel (200) according to any one of claims 5 to 9.