WO2023115074A1

WO2023115074A1 - Single use syringe

Info

Publication number: WO2023115074A1
Application number: PCT/ZA2022/050066
Authority: WO
Inventors: Ho Hiu Wai; Lui Wing Kit
Original assignee: Universal Brand Group (Pty) Limited
Priority date: 2021-12-13
Filing date: 2022-12-06
Publication date: 2023-06-22

Abstract

This invention relates to a single use syringe comprising a barrel, having a continuous inner wall and terminating in two ends, defining a passageway therebetween for fluid to pass through the syringe; a plunger rod arrangement, located proximate the first end, for urging the fluid selectively through the passageway; the plunger being movable selectively between an operative condition, in which it is free to move through the passageway, and a locked condition, in which it is held captive within the barrel; a needle-locking formation, for locking a needle irreversibly to the barrel, and a rod-locking element, for locking the plunger rod selectively within the barrel, trapping it in the locked condition; characterised in that a needle of any dimension is accommodated by the needle-locking formation, and characterised further in that the syringe is capable exclusively of single use. The invention relates, further, to a hypodermic syringe kit.

Description

SINGLE USE SYRINGE

Field Of The Invention

THIS INVENTION relates, broadly, to a single use syringe. More particularly, but not exclusively, the invention has application to universal sizing single use syringe.

Background To The Invention

In this specification, the term “syringe” is understood to mean a hypodermic syringe, as used for the injection of medication transdermally, intravenously into the body

For decades, inventions have been proposed for preventing the repeated use of a single syringe, primarily to avoid the transfer of contagious diseases, and in a measure to deter narcotics abuse. A number of these (including: US 2004/002435 and US 20030028149) extend to methods of rendering the syringe locked and unusable after its first (and only application).

Notwithstanding the obvious advantages of such syringes, the prior art still suffers from at least one significant drawback, namely: the hypodermic needle in any given syringe is not necessarily suitable or optimal for any particular patient. Purely by way of example: a 1” (25.4 mm) length, 23 gauge or 25 gauge needle are the most commonly used hypodermic needle used for injecting neonates; conversely, a 1 .5” (38 mm) length 22 - 25 gauge needle is the most commonly used hypodermic needle used for injecting obese adults. It will be appreciated readily but the person skilled in the art that the selection of appropriate gauge needle is no trivial matter: an incorrect choice could easily result in harm, or even death, to the patient. The problem noted is that most syringes are manufactured to include a single, predetermined gauge needle only - this preselection alone could easily render the syringe inappropriate and/or dangerous for use with any given patient.

Object Of The Invention

It is an object of the present invention to provide a single use syringe that will overcome, at least partially, the disadvantages described above.

Summary Of The Invention

According to a first aspect of the invention, there is provided a single use syringe comprising: a barrel, having a continuous inner wall and terminating in two ends, defining a passageway therebetween for fluid to pass through the syringe; • a plunger rod arrangement, located proximate the first end, for urging the fluid selectively through the passageway; the plunger being movable selectively between an operative condition, in which it is free to move through the passageway, and a locked condition, in which it is held captive within the barrel;

• a needle-locking formation, for locking a needle irreversibly to the barrel, the needle locking formation being located proximate the second end of the barrel, characterised in that a needle of any dimension is accommodated by the needle-locking formation, and characterised further in that the syringe is capable exclusively of single use.

The syringe may include a rod-locking element, for locking the plunger rod selectively within the barrel, trapping it irreversibly in the locked condition.

Preferably, the rod-locking element comprises a rib and flange formation. Alternatively, the rod-locking element comprises a series of barb formations located on the inner wall of the barrel, characterised in that, once the rod is moved past the barb formations in use, it lacks sufficient inertia to reverse its path, thus keeping it trapped in the locked condition.

Preferably, the needle-locking formation is a Luer-lock fitting.

Alternatively, the needle-locking formation may be a Luer-slip fitting. Preferably, the syringe has a capacity to accommodate 0.2 ml

- 10 ml of fluid within the barrel. More preferably, the syringe has a capacity to accommodate 0.5 ml - 5 ml of fluid within the barrel

According to a second aspect of the invention, there is provided a hypodermic syringe kit, the kit comprising:

• a single use syringe, of the type described above, the syringe including a needle-locking formation; and

• a series of hypodermic needles of variable dimension, characterised in each of the needles is capable of accommodation selectively by the needle-locking formation, and characterised further in that the syringe is capable exclusively of single use.

The needles may be selected from the group consisting of: a 23 gauge needle, a 25 gauge needle, 1” and 1.5” length and a combination of these.

Brief Description Of The Drawings

In order to describe the invention, embodiments thereof are described hereunder, purely as examples, without limiting the scope of the invention, wherein:

Figure 1 is an isometric, partially exploded view of the syringe in accordance with the invention; Figure 2 is an isometric view of the syringe shown in Figure 1 , after use

(ie: with the plunger rod in the locked condition);

Figure 3 is a longitudinal section of the syringe depicted in Figure 1 ;

Figure 4a is an enlarged depiction, and longitudinal section, of the area depicted within circle “A” in Figure 3;

Figure 4b is an enlarged depiction, and longitudinal section, of the area depicted within circle “B” in Figure 3;

Figure 5 is a longitudinal section of the syringe depicted in Figure 2;

Figure 6a is an enlarged depiction, and longitudinal section, of the area depicted within circle “C” in Figure 5;

Figure 6b is an enlarged depiction, and longitudinal section, of the area depicted within circle “D” in Figure 5; and

Figure 7 is an isometric view of the syringe depicted in Figure 2, but with the needle shield in the closed position.

Detailed Description Of The Drawings Referring to the figures, which depict a preferred embodiment of the invention, a single use syringe in accordance with the invention is provided, and is referred to generally by numeral 10. The syringe 10 comprises: a barrel 20 and plunger rod 30. The barrel 20 has a continuous inner wall (not references) by virtue of its substantially cylindrical inner core. The barrel 20 terminating in two ends, namely a first end 60, proximate the plunger rod 30, and a second end 70, proximate the hypodermic needle 50, which is discussed in further detail below. The inner wall of the barrel 20 defines a passageway through which fluid (ie: medication) passes through the syringe 10 in use.

In use: the operator (not shown) of the syringe 10 will commence use of the syringe 10 by loading it with a preselected volume of liquid medication (not depicted). Typically, this is done by inserting needle 50 into a vial of medication, and drawing back on plunger rod 30, in the direction of arrow Y - Y’. The preselected volume of medication is confirmed with reference to the graduations marked on the barrel 20. This motion draws the medication into the medication into the passageway, where it remains primed for injection into the subject. In another embodiment of the invention, namely: a vaccine dose, the preselected volume of medication is preloaded into the barrel 20 on manufacture.

Preferably, the syringe 10 has a capacity to accommodate 0.2 ml - 10 ml of fluid within the barrel. More preferably, the syringe 10 has a capacity to accommodate 0.5 ml - 5 ml of fluid within the barrel - these being common graduations seen typically in the field.

The primary purpose of plunger rod 30 is to urge the medication through the passageway. The plunger rod 30 is movable selectively between an operative condition and a locked condition. More specifically, in the operative condition, the plunger rod 30 is free to move through the passageway, precisely as has been described in the preceding paragraph, and the description immediately below. Conversely, when in the locked condition, the plunger rod 30 is held captive within the barrel 20.

In order to describe these two conditions more fully, it is necessary, first, to describe the needle-locking formation 40, which is also an essential component of the invention. The needle-locking formation 40 is located proximate the second end 70 of the barrel 20. The purpose of the needle-locking formation 40 is to lock a needle 50 irreversibly to the barrel 20. In practice, the user of the syringe 10 will select the most appropriate needle 50 for use with a particular recipience of the medication. So, by way of example: if the medication is to be injected into a neonate, a 23 Gauge 1” needle would be an appropriate selection. Conversely, if the medication is to be injected into a 125 kg, 2m tall adult, a 22 Gauge 1.5” needle would be an appropriate selection.

In the accompanying figures, the needle-locking formation 40 takes the form of a traditional Luer® lock, which is well known in the field. The needle 50 includes a complimentary-shaped “male” lock formation 90. That complimentary formation is press-fit into the “female” needle-locking formation 40. Critically: once engaged, the press-fit arrangement is incapable of being reversed, and the needle-locking formation 40 and complimentary-shaped lock formation 90 are held fast. This is quite intentional: the consequence of this design is that the syringe 10 is capable only of single use, as the needle 50 cannot be removed from barrel 20 after use - at least: not without causing catastrophic damage to the barrel 20 when attempting separation from the needle 50.

The syringe 10 further includes a rod-locking element 100, for locking the plunger rod 30 selectively within the barrel 20, trapping it irreversibly in the locked condition. The rod-locking element 100 comprises a rib and flange formation. More specifically: a terminal end of the plunger rod 30 includes a rib formation 110, and the inner wall of the barrel 20 includes a continuous flange 120. In use, when the medication is injected into the subject, the medication travels through the passageway of the barrel 20 in the direction of arrow Z - Z’. During the course of that motion, rib 110 will move past flange 120. At the end of that motion, the plunger rod 30 lacks inertia to reverse that motion, and the plunger rod 30 remains trapped inside barrel 20 in the locked condition. This, too, is quite intentional: the consequence of this design is also that the syringe 10 is capable only of single use, as the needle

50 cannot be removed from barrel 20 after use. In an alternative embodiment of the invention (not depicted) the rod-locking element 100 takes the form of a series of barbs.

According to a second aspect of the invention, there is provided a hypodermic syringe kit (not depicted), which comprises a single use syringe 10, of the type described above and a series of hypodermic needles of variable dimension. The advantage of this kit will be immediately apparent: it allows for a user to have a convenient, universal supply of a range of needles at any time. This is particularly useful in the field or in remote locations, where stock of needles is not readily available, or not available consistently.

Ideally, the needles in the kit are selected from the group consisting of a combination: a 1” length 23 gauge needle, and a 1.5” length 22 gauge needle. This combination is particularly useful because, cumulatively, these cover an extremely broad spectrum of body types and age groups. The expert in the field will appreciate that multiple variations, permutations and combinations of needles will be possible, to suit particular environments and needs. In each case, the advantage achieved is a single use syringe 10 that has application universally to any size needle 50.

It will be appreciated that the advantages achieved through the use and exercise of this invention overcomes, to at least some degree, each one of the disadvantages described above. It will be appreciated, further, that numerous embodiments of the invention could be performed without departing from the scope of the invention as defined in the consistory statements above.

Claims

Claims A single use syringe comprising:

• a barrel, having a continuous inner wall and terminating in two ends, defining a passageway therebetween for fluid to pass through the syringe;

• a plunger rod arrangement, located proximate the first end, for urging the fluid selectively through the passageway; the plunger being movable selectively between an operative condition, in which it is free to move through the passageway, and a locked condition, in which it is held captive within the barrel;

• a needle-locking formation, for locking a needle irreversibly to the barrel, the needle locking formation being located proximate the second end of the barrel, characterised in that a needle of any dimension is accommodated by the needle-locking formation, and characterised further in that the syringe is capable exclusively of single use. A syringe according to claim 1 which further includes a rod-locking element, for locking the plunger rod selectively within the barrel, trapping it irreversibly in the locked condition. A syringe according to claim 2, wherein the rod-locking element comprises a rib and flange formation. A syringe according to claim 2, wherein the rod-locking element comprises a series of barb formations located on the inner wall of the barrel, characterised in that, once the rod is moved past the barb formations in use, it lacks sufficient inertia to reverse its path, thus keeping it trapped in the locked condition. A syringe according to claim 1 , wherein the needle-locking formation is a selected from the group consisting of a Luer-lock fitting and a Luer-slip fitting. A syringe according to claim 1 , wherein the syringe has a capacity to accommodate 0.2 ml - 10 ml of fluid within the barrel. A hypodermic syringe kit, the kit comprising:

• a single use syringe, of the type described in claims 1 - 6, the syringe including a needle-locking formation; and

• a series of hypodermic needles of variable dimension, characterised in each of the needles is capable of accommodation selectively by the needle-locking formation, and characterised further in that the syringe is capable exclusively of single use. A hypodermic syringe kit according to claim 8, wherein the needles are selected from the group consisting of: a 23 gauge needle, a 25 gauge needle, 1” length needle and 1.5” length needle, and a combination of these.