Infusion set connector

Abstract

An infusion set connector. The connector comprises a body comprising a tubing connector for overmounting a tube, and a needle comprising a lumen. A first end of the needle extends through the tubing connector such that the lumen provides a fluid flowpath through the tubing connector, the flowpath terminating at an open end of the tubing connector for receiving a fluid.

Description

[0001] Infusion set connector

[0002] TECHNICAL FIELD

[0003] The invention relates to an infusion set connector. The invention also relates to an infusion set comprising such a connector.

[0004] BACKGROUND

[0005] Infusion sets are medical devices used to deliver fluids, such as drugs, nutrients, or therapeutic agents, from a reservoir or pump into a patient’s body in a controlled manner. They are widely employed in the management of chronic conditions, such as diabetes, where insulin is administered subcutaneously over extended periods, as well as in other therapies requiring continuous or repeated infusion.

[0006] Different infusion sets require different flow rates depending on several factors, e.g., the purpose of the treatment, the type of fluid being delivered. In infusion sets, typically subcutaneous, though intramuscular variants are known, medications are typically delivered at relatively slow rates, though these commonly range from 0.1 to 10 mL / hr, depending on the drug and the site of administration. For insulin delivery, insulin is administered subcutaneously at rates measured in units per hour: one unit of insulin is defined as the amount of insulin required to lower blood glucose by a specific amount. Basal rates (the continuous delivery of small amounts of insulin throughout the day) generally range from 0.5 to 2.0 units per hour. However, other infusion sets can have higher rates, e.g., from 20 to 150 mL / hr.

[0007] The tubing in an infusion set can play a significant role in determiningthe flow rate. The flow rate is influenced by various factors related to the tubing, such as its diameter, length, and material selection. As such, designers of infusion sets may look to modify the flow rate in a system by modifying the tubing, e.g., increasing the flow rate in infusion sets can be achieved by using larger diameter tubing, shortening the tubing length, or optimising the tubing material to provide smooth internal surface. When integrating larger diameter tubing with existing designs, adapters or transition pieces may be necessary. These adapters should be designed to reduce or mitigate challenges in installation, e.g., pushing larger diameter tubing onto a fitting requires more force. This can make installation of the tubing onto the adaptor more challenging, and / or lead to deformation which can affect the fit and the stability of the connection.

[0008] It is an object of embodiments of the invention to provide an improved infusion set connector, and / or at least mitigate one or more problems associated with known arrangements.

[0009] SUMMARY OF THE INVENTION

[0010] Accordingto an aspect of the invention, there is provided an infusion set connector comprising: a body comprising a tubing connector for overmounting a tube; and a needle or tubular member comprising a lumen, wherein a first end of the needle extends through the tubing connector such that the lumen provides a fluid flowpath through the tubing connector, the flowpath terminating at an open end of the tubing connector for receiving a fluid. By extending through the tubing connector, the needle improves the strength and / or stiffness of the tubing connector thereby helping to resist deformation and / or collapse of the tubing connector when overmounting a length of tubingthereon. This may improve the efficacy of the fluid connection of a tube, or tubing, to the tubing connector.

[0011] In certain embodiments, a second end of the needle may extend from the body and comprises a sharpened tip. Additionally, or alternatively, the first end of the needle may extend through a total length of the tubing connector.

[0012] In certain embodiments, the lumen may wholly provide the flowpath through the tubing connector. The tubing connector may frustoconical or have a frustoconical region at the open end thereof. The body may be of one-piece construction, and / or the connector may of two-piece construction consisting of the body and the needle. In certain embodiments, the needle may extend along a centreline of the infusion set connector. Additionally, or alternatively, the body may be formed of a plastic, such as a polyoxymethylene or a polypropylene, and / or the needle may be formed of a metal, such as a stainless steel. The infusion set connector may comprise a retaining portion for maintaining a fluidic connection formed by the medical connector.

[0013] According to an another aspect of the invention, there is provided an infusion set comprising the infusion set connector as described above.

[0014] In certain embodiments, the infusion set may comprise a length of tubing fluidly connected to the tubing connector of the infusion set connector by being overmounted thereon. An inner diameter of the length of tubing may be at least 0.50 mm and / or up to 1 .20 mm, or at least 0.65 mm and / or up to 1 .00 mm. The fluidic connection of the tubing connecter to the tubing may be free of adhesive.

[0015] In certain embodiments, fluid delivery system may comprises a cannula hub for forming a fluidic connection of the medical connector to the cannula hub. The cannula hub may comprises a septum for forming the fluidic connection of the medical connector to the needle hub by receivingthe needle by the needle piercing the septum. Additionally, or alternatively, the cannula hub may have an underside configured for attachment to a skin surface of a user. The fluidic connection of the medical connectorto the cannula hub may be maintainable by the retaining portion.

[0016] In certain embodiments there is provided an infusion set comprising an infusion set connector, the infusion set connector comprising: a body comprising a tubing connector for overmounting a tube; and a needle or tubular member comprising a lumen, wherein a first end of the needle extends through the tubing connector such that the lumen provides a fluid flowpath through the tubing connector, the flowpath terminating at an open end of the tubing connectorfor receiving a fluid, wherein the infusion set comprises a length of tubing fluidly connected to the tubing connector by being overmounted thereon and / or the fluidic connection of the tubing connecter to the tubing is free of adhesive.

[0017] According to an another aspect of the invention, there is provided an infusion set assembly comprising an infusion set as described above and an inserter device or injection port, the inserter device or injection port.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying figures, in which:

[0020] Figures 1 s and 1 b are plan and side views, respectively, of an infusion set assembly accordingto an embodiment of the invention;

[0021] Figure 2a and 2b are plan views and a longitudinal section through line A-A, respectively, of an infusion set connector of an infusion set of the infusion set assembly of Figures 1 a and 1 b; and

[0022] Figure 3 is an enlarged view of a region B of the longitudinal section of the infusion set connector of Figure 2b.

[0023] DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0024] Generally, embodiments of the invention have application in infusing, delivering, administering, injecting or dispensing a substance into the body of a patient. Certain embodiments of the invention may have particular application in introducing a liquid into the body of a patient, and / or subcutaneous supply of a liquid medicament, e.g., insulin, into the body of a patient.

[0025] Figures 1 a and 1 b show an infusion set assembly 10 according to an embodiment of the invention. The infusion set assembly 10 comprises an infusion set 12 and an inserter device 14, the infusion set 12 comprising a cannula hub 16 and a detachable length of tubing 18. The cannula hub 16 comprises a hub body 20 and a cannula 22 projecting from an underside 24 thereof, the cannula 22 being a soft cannula formed of a flexible polymeric material. The cannula hub 16 secures and supports the cannula 22 in an infusion site of a patient, and provides a fluidic connection between the cannula 22 and the tubing 18. As in the illustrated embodiment, the underside 24 of the cannula hub 16 may be provided with a skin adhesive layer 26, e.g., a plaster, a skin adhesive surface of which may be covered with a release paper (not shown). The skin adhesive layer 26 holds the hub 16 in place on the skin of the patient, thereby securing the cannula 22 in the infusion site. However, the cannula hub 16 may be otherwise configured for attachment to the skin surface of the patient. The tubing 18 provides medicament communication between the needle hub 16 and an infusion pump (not shown). The detachable nature of the tubing 18 allows for, inter alia, easier tubing changes, which may reduce the need to replace the entire set 12.

[0026] The inserter device, or inserter, 14 assists in the insertion of the cannula 22 into the skin. The inserter 14 comprises an inserter body 28 and an insertion needle 30 extendingtherefrom, the insertion needle 30 beinga rigid needle, and havinga sharp, bevelled tip for smooth penetration of the skin. While Figure 1 b shows the inserter 14 spaced apart from the cannula hub 16, the assembly 10 is typically supplied for use having the cannula 22 pre-loaded onto the insertion needle 30. The insertion needle 30 is usually long enough to accommodate the entire length of the cannula 22. The insertion needle 30 acts as a guide, leadingthe cannula 22 into the correct position under the skin upon insertion. During the insertion process, the insertion needle 30 is used to puncture the skin, creating a path along which the soft cannula 22 follows. The insertion needle 30 is subsequently withdrawn from the skin, while the cannula 22 remains in place, allowingfor medicament delivery.

[0027] The infusion set 12 further comprises an infusion set connector 32, the purpose of which is to provide a fluidic connection between the tubing 18 and the cannula hub 16. Figures 2a, 2b and 3 best show the connector 32. The connector 32 comprises a body 34 having a tubing connector 36 for overmounting the tubing 18, and a needle 38. Overmounting refers to a method in which an article is slipped over a point of fixation, in this case the tubing 18 being slipped over the tubing connector 36, by being pushed directly over, or onto, the point of fixation. The tubing connector 36 may be a protuberance, projection or similar, extending from the body 34 of the connector 32. However, as in the illustrated embodiment, the tubing connector 36 may be recessed into the body 34, i.e., the tubing connector 36 may extend from the body 34 within a recess 34a of the body 34. The tubing connector 36 has a free end 36a, over which the tubing 18 is mountable, the free end 36a being an open end exposing a flowpath. The flowpath extends through the centre of the tubing connector 36, and further through the remainer of the body 34 of the connecter 32. The flowpath, at least the extent to which it extends through the connector 32, terminates at the open end of the tubing connector 36 for receiving a fluid, e.g., for receiving a fluid from the tubing 18.

[0028] Overmounting the tubing 18 onto tubing connector 36 forms a fluidic connection therebetween, as an inside diameter of the tubing 18 is slightly smaller or equal to the outer diameter of the tubing connector 36. When the tubing 18 is pushed onto the tubing connector 36, the tightness of the fit creates friction that holds the tubing 18 in place and seals the tubing 18 to the connector 36. In certain embodiments, this relies solely on the snugness of the fit. However, the tubing connector 36 comprise have small ridges or barbs (not shown) on an outer surface thereof. The ridges or barbs are angled or otherwise configured in such a way that they allow the tubing 18 to be pushed on to the tubing connector 36 with relative ease, but resist being pulled off. More specifically, the ridges or barbs may dig into an inner wall of the tubing 18, enhancing the fit and thereby inhibiting accidental disconnection. To facilitate the ease of overmounting the tubing 18, the tubing connector 36 may additionally, or alternatively, be frustoconical in shape or have a frustoconical shaped region at the open end 36a thereof, or be otherwise similarly shaped. In certain embodiments, an adhesive may be used to facilitate holdingthe tubing 18 in place and / or sealing the tubing 18 to the connector 36. However, in certain embodiments the fluidic connection of the tubing 18 to the connector 36 is desirably free of adhesive, as this may reduce the risk of contamination of a fluid in the flowpath by the adhesive. In such adhesive free embodiments, the overmounting of the tubing 18 alone forms the seal.

[0029] The needle 38 provides a fluidic connection between the connector 32 and the cannula hub 18. The needle 38 has first and second ends 38a, 38b. The first end 38a extends through the body 34 of the connector 32, and the second end 38b extends from the body 34 in order to form the fluidic connection to the cannula hub 18. The needle 38 is a hollow needle, i.e., the needle 38 has a lumen 40 extending through the centre thereof, which allows fluid to be conveyed through the needle 38. In the illustrated embodiment, the needle 28 is straight and extends along a centreline of the connector 32, though in certain embodiments one or neither of these features may be present.

[0030] The first end 38a of the needle 38 extends through the tubing connector 36 such that the needle 38, or more specifically the lumen 40, provides the flowpath through the tubing connector 36. As shown in the illustrated embodiment, the needle 38, and therefore the lumen 40, may wholly provide the flowpath through the tubing connector 36, i.e., the first end 38a of the needle 38 may extend through a total length of the tubing connector 36, the first end 38 being coterminous with, i.e., has the same extent as, the free end 36a of the tubing connector 36. Though, in certain embodiments, the needle 38 may terminate slightly before the end 36a of the tubing connector 36, in which case the flowpath will continue through the tubing connector 36 beyond the first end 36a of the needle 28, or slightly after.

[0031] By extending through the tubing connector 36 to provide the flowpath, the needle 38 supplements the radial strength of the tubing connector 36. Radial strength refers to the ability of a material, structure, or component to withstand forces applied radially, i.e., from its centre outward or from the outside toward its centre, the latter being critical in the ability of the tubing connector 36 to resist radial forces applied thereto by the tubing 18 when the tubing 18 is overmounted onto the tubing connector 36. Therefore, the tubing connector 36 and the needle 38 together resist the radial forces applied by the tubing 18.

[0032] This supplemental arrangement is particularly advantageous, as it allows a greater range of possible dimensions of the tubing connecter 36 or, more specifically, the outer diameter of the tubing connector 36, including dimensions which may otherwise result in the tubing connector 36 lacking sufficient radial strength for overmounting the tubing 18 thereon, and / or possible materials. The body 34 of the connector 32, and hence the tubing connector 36, is desirably made of a plastics material. This is desirable for several reasons, including plastics parts being relatively inexpensive to mass produce, plastics can be moulded into complex shapes with varying levels of flexibility, hardness or softness, depending on the specific requirements of the part, and medical-grade plastics are durable, easily sterilised through various methods and resistant to chemicals, including medications, bodily fluids and cleaning agents. However, given the relatively small outer diameter of the tubing connector 36, which must be at least approximately equal to the inner diameter of the tubing 18, there may be insufficient material available to provide the required strength for overmounting the tubing 18. This can be further exacerbated depending on the desired inner diameter of the flowpath through the tubing connector 36, i.e., the larger the diameter of the flowpath relative to the outer diameter of the tubing connector 36 the weaker the tubing connector 36 alone will be, as there may be only a small amount of plastics material in the crosssection of the tubing connector 36.

[0033] By effectively replacing or otherwise incorporating a portion of a plastics crosssection with the needle 38, resistance of the tubing connector 36 to forces applied radially thereto is increased. This is because the needle 38 is made of metal, such a stainless steel. The same cross-section of metal will generally withstand higher stresses compared to that of plastic, from which the tubing connector 36 is desirably made.

[0034] A particularly suitable stainless steel from which the needle 38 may be made is American Iron and Steel Institute (AISI) 304 stainless steel, having 18% chromium and 8% nickel, along with other alloys that enhance its stainless steel qualities. Particularly suitable plastics from which the body 34 of the connector 34 may be made include polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), methyl methacrylate acrylonitrile butadiene styrene (MABS), polycarbonate (PC), and polypropylene (PP).

[0035] The alternative is that the tubing 18 can be mounted directly onto the needle 38, but then to vary the diameter of the tubing 18 the diameter of the needle 38 would need to be varied also. This may be undesirable, as it could impact the compatibility of the connector 32 with standard or existing cannula hubs, require multiple variants to ensure that compatibility is possible, or require a more complex connector.

[0036] In certain embodiments, the outer diameter (OD) of the needle 38 may be at least 0.40 and / or up to 0.60 mm. Additionally, or alternatively, the inner diameter (ID) of the tubing 18 may be at least 0.65 to 1 .00 mm (+0.015 / -0.08). Example values for the ID of the tubing 18 and the OD of the needle 38 may be as follows: Note that the inner diameter of the tubing 18 may be at least substantially the same as the outer diameter of the tubing connector 36, though the outer diameter of the tubing connector 36 may vary of the length thereof, e.g., due to the having a frustoconical shape.

[0037] In certain embodiments, the ID of the tubing 18 may be at least 0.05 mm smaller than the OD of thetubingconnector36. In certain embodiments, the ID of the tubing 18 may approximately 0.10 mm smaller than the OD of the tubing connector 36.

[0038] As the reader will appreciate, the difference in diameter between the ID of the tubing 18 and the OD of the needle 38 leaves a gap that does not result in a sealing fit therebetween. By forming the infusion set connector 32 havingthe tubing connector 36 that surrounds / encapsulates the needle 38 enables a snugness of fit between the tubing 18 and the needle 38. This snugness of fit allows for the overmounting of the tubing 18 to the needle 38 and may thereby sealing connect one to the other, preferably without the need for an adhesive, as described above.

[0039] A combination of overmounting and an adhesive-free seal provides a robust, reliable connection that avoids the complications of glue joints, eliminates risks of leakage or chemical contamination, and simplifies the overall manufacturing process. The result is a cleaner, safer and more durable interface between tubing and needle, achieved entirely through the precision of the overmounted design rather than reliance on secondary bonding agents.

[0040] Without the needle 38, the overmoulded tubing 18 risks crushing / collapsing the tubing connector 36, and consequently the flowpath, resulting in closure or significant occlusion thereof, from the radially inward force applied by the tubing 18 to the tubing connector 36.

[0041] More generally, the arrangement of the needle 38 extending through the tubing connector 36 allows for a simple, robust and / or low-cost construction of the connector 32. As shown in the illustrated embodiments, the connector 32 may be simply constructed as a two-piece component, constructed of only the body 34 and the needle 38, e.g., a plastics body and a metal needle. This simple construction, which minimises individual component parts improves reliability and durability, by better withstanding frequent use (due to having fewer failure points), sterilisation, and environmental stress, ensuring consistent performance over time. The simple construction is also cost-effective, providing faster production times and lower costs, enabling large-scale production, which is important for widespread distribution in healthcare systems.

[0042] As shown in the illustrated embodiment, the second end 38b of the needle 38 extends from the body 34 and may comprise a sharpened tip. The second end 38b of needle 38 may engage with a septum 42 (denoted in Figure 1 b) of the needle hub 18 to form the fluidic connection between the connector 32 and the cannula hub 18, i.e., the needle hub 18 receiving the needle 38 by the needle 38 piercingthe septum 42. The septum 42 is typically a self-sealing, flexible membrane that acts as a barrier to maintain the sterility of the flowpath as it extends through the needle hub 18 and further through the cannula 22. Additionally, or alternatively, to maintain the fluidic connection, the connector 32 may comprise at least one retaining portion 44, which in the illustrated embodiment is a flexible or snap-fit component that engages with the needle hub 18, or a corresponding component thereof, to hold the connector 32 in place against the needle hub 18. More specifically, as shown in the illustrated embodiment, the at least one retaining portion 44 may provided by a pair of flexible arms, each of which is formed integrally as part of the body 34 of the connector 32. Septa and such snap-fit connections are widely used in medical devices — particularly modular medical devices such as the fluid delivery systems described herein — largely due to their sterility, ease of use, and cost-efficiency, and it is should be understood that these may be provided in various suitable forms.

[0043] Generally, unless stated otherwise, the materials for making embodiments of the invention and / or components thereof may be selected from suitable materials conventional in the art, e.g., metal, metallic alloys, ceramics, plastics. Similarly, embodiments of the invention and / or components thereof may manufactured using suitable methods conventional in the art, e.g., injection molding, blow molding, or tube drawing. Connecting the needle 38 to the body 34 of the connector 32, and / or introducing the needle 38 into the body 34 and / or the tubing connector 36 may be by any suitable means, e.g., adhesive bonding, overmolding, crimping, or heat sealing.

[0044] The invention is not restricted to the details of any foregoing embodiments. In particular, it should be noted that the invention primarily concerns the infusion set connector 32 and the tubing connector 36. In certain embodiments, the needle 38 may be replaced with a tubular member, i.e., a tubular member having a lumen. Therefore, references throughout description and claims of this specification to the needle 38 should be understood to apply, mutatis mutandis, to such tubular member. In embodiments comprising the tubular member, the tubular member may be wholly enveloped within the body 34 of the infusion set connector 32, and the fluidic connection between the infusion set connector 32 and the cannula hub 18, or other component to which the infusion set connector 32 f luidica Uy connects, may be provided by any suitable means, e.g., a Luer fitting. The infusion set connecter 32 and / or the tubing connector 36 may be incorporated into commercially available or custom-designed fluid delivery systems and / or infusion sets. Details of the fluid delivery system and the infusion set of the illustrated embodiment are provided to aid description of the invention.

[0045] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. Features, integers, or characteristics described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. In particular, the words “certain embodiments” are to be understood to mean any embodiment described, illustrated, or otherwise disclosed herein, unless expressly stated otherwise. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0046] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

CLAIMS1 . An infusion set connector comprising: a body comprising a tubing connectorfor overmounting a tube; and a needle comprising a lumen, wherein a first end of the needle extends through the tubing connector such that the lumen provides a fluid flowpath through the tubing connector, the flowpath terminating at an open end of the tubing connector for receiving a fluid.

2. A infusion set connector according to claim 1 , wherein a second end of the needle extends from the body and comprises a sharpened tip.

3. A infusion set connector according to claim 1 or 2, wherein the first end of the needle extends through a total length of the tubing connector.

4. A infusion set connector according to any preceding claim, wherein the lumen wholly provides the flowpath through the tubing connector.

5. A infusion set connector according to any preceding claim, wherein the tubing connector is frustoconical or has a frustoconical region at the open end thereof.

6. A infusion set connector accordingto any preceding claim, wherein the body is of one-piece construction.

7. A infusion set connector according to any preceding claim, wherein connector is of two-piece construction consisting of the body and the needle.

8. A infusion set connector according to any preceding claim, wherein the needle extends along a centreline of the infusion set connector.

9. A infusion set connector according to any preceding claim, wherein the body is formed of a plastic, such as a polyoxymethylene or a polypropylene.

10. A infusion set connector according to any preceding claim, wherein the needle is formed of a metal, such as a stainless steel.

11. An infusion set connector according to any preceding claim, wherein the infusion set connector comprises a retaining portion for maintaining a fluidic connection formed by the infusion set connector.

12. An infusion set comprising an infusion set connector according to any proceeding claim.

13. An infusion set according to claim 11 , wherein the infusion set comprises a length of tubing fluidly connected to the tubing connector of the infusion set connector by being overmounted thereon.

14. An infusion set according to claim 13, wherein an inner diameter of the length of tubing is at least 0.50 mm and / or up to 1 .20 mm.

15. An infusion set according to claim 13 or 14, wherein the fluidic connection of the tubing connecter to the tubing is free of adhesive.

16. An infusion set according to any of claims 12 to 15, wherein the infusion set comprises a cannula hub for forming a fluidic connection of the infusion set connector to the cannula hub.

17. An infusion set accordingto claim 16, wherein the cannula hub comprises a septum for forming the fluidic connection of the infusion set connector to the needle hub by receiving the needle by the needle piercingthe septum.

18. An infusion set accordingto claim 16 or 17, wherein the cannula hub has an underside configured for attachment to a skin surface of a user.

19. An infusion set according to claim 16, 17 or 18, when dependent upon claim 11 , wherein the fluidic connection of the infusion set connector to the cannula hub is maintainable by the retaining portion.

20. An infusion set assembly comprising an infusion set according to any of claims 12 to 19, wherein the infusion set assembly comprises an inserter device or injection port.

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