Fluid path tube

Abstract

In some examples, a tubing assembly for an injection device includes a tubing having a first end and a second end, the tubing defining a lumen having a constant inner diameter and a constant outer diameter from the first end to the second end, a first connector coupled to the first end, the first connector having a first enlarged section, a first tapered section and a first narrowed section, and a second connector coupled to the second end, the second connector having a second enlarged section, a second tapered section and a second narrowed section.

Description

25879 FLUID PATH TUBE CROSS-REERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 606,471, filed December 5, 2023, the disclosure of which is incorporated herein by reference in its entirety. FIELD OF THE DISCLOSURE

[0002] The present disclosure relates generally to medical devices for delivery of drugs. More specifically, the present disclosure relates to tubing assemblies for use with pumps, injectors and other medical devices. BACKGROUND OF THE DISCLOSURE

[0003] External drug pumps are typically used to deliver substances (e.g., large molecules which cannot be digested when administered orally) to patients. For example, such devices are commonly used to infuse a basal rate of insulin to subjects suffering from diabetes, as an alternative to insulin injections by an insulin syringe or an insulin pen. Typically, the pump is adhered to the abdomen of the patient and delivers the substance to the patient via a cannula that is inserted into the patient's skin. Traditional pumps or injectors are limited. For examples, the injection forces of traditional injectors may be suboptimal or injection time may be too long. This may be particularly an issue with highly viscous substances.

[0004] Thus, there exists a need for devices that work with and advance the methods of safely using injectors to ensure proper delivery of high viscosity medicaments. SUMMARY OF THE DISCLOSURE

[0005] In some examples, a tubing assembly for an injection device includes a tubing having a first end and a second end, the tubing defining a lumen from the first end to the second end, the tubing having a first terminal portion, a first tapered portion, a central portion, a second tapered portion, and a second terminal portion.

[0006] In some examples, a tubing assembly for an injection device includes a tubing having a first end and a second end, the tubing defining a lumen having a constant inner diameter and a constant outer diameter from the first end to the second end, a first connector coupled to the firstend, the first connector having a first enlarged section, a first tapered section and a first narrowed section, and a second connector coupled to the second end, the second connector having a second enlarged section, a second tapered section, and a second narrowed section. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Various embodiments of the presently disclosed devices are disclosed herein with reference to the drawings, wherein:

[0008] FIG.1A-1B are a schematic representation and a photograph of a common tubing assembly used with an apparatus for administering a substance to a subject;

[0009] FIG.1C is a schematic representation of a tubing assembly according to a first embodiment;

[0010] FIG.2 is a chart showing potential dimensions for components of an apparatus for administering a substance to a subject including a tubing assembly according to the first embodiment;

[0011] FIGS.3-4 are photographs and schematic representations of a tubing assembly according to another embodiment.

[0012] FIG.5 is a chart showing potential dimensions for a tubing assembly according to another embodiment;

[0013] FIGS.6, 7A, and 7B are schematic representations of a tubing assembly having connectors according to another embodiment;

[0014] FIG.7C is a photograph of a tubing assembly having connectors being coupled to cannulas according to one embodiment;

[0015] FIG.8 is a photograph of a testing assembling to perform experiments on the tubing assembly; and

[0016] FIG.9 is a graph showing results of the experiments performed by the testing assembly of FIG.8.

[0017] Various embodiments are described below with reference to the appended drawings. It is to be appreciated that these drawings depict only some embodiments of the disclosure and are therefore not to be considered limiting of its scope.DETAILED DESCRIPTION OF THE DISCLOSURE

[0018] Despite the various improvements that have been made to injectors, conventional methods suffer from some shortcomings as discussed above. Specifically, conventional methods and devices may require longer than desired injection times, particularly when used with high viscosity substances. The long injection times lead to the device being applied and / or attached to the patient for longer than necessary, which may lead to patient discomfort and dissatisfaction. Patient discomfort and dissatisfaction may also lead to noncompliance.

[0019] Therefore, there is a need for further improvements to the devices and methods used to deliver medication, particularly for high viscosity medicaments. Among other advantages, the present disclosure may address one or more of these needs.

[0020] As used herein, the term “proximal,” when used in connection with a component of an injector, refers to the end of the component closest to the injector; whereas the term “distal,” when used in connection with a component of an injector, refers to the end of the component closest to the needle insertion site during use. The terms “trailing” and “leading” are to be taken as relative to the operator’s fingers (e.g., physician) of the injector. “Trailing” is to be understood as relatively close to the operator’s fingers, and “leading” is to be understood as relatively farther away from the operator’s fingers. Moreover, as used herein, the terms “medicament,” “medication,” and “drug” are used generically interchangeably and it will be understood that the ampoules described herein may be used to store, deliver or administer vaccines, biologics, therapeutic, medicaments, topical ointments, and the like.

[0021] Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “lower” and “upper” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”. The terminology includes the words noted above, derivatives thereof and words of similar import.

[0022] To better illustrate the problems associated with conventional delivery tubing, FIGS. 1A-1B show an example of a tubing assembly 1000 that includes a cartridge needle hub 1020a that terminates in a cartridge needle or cartridge cannula 1022a for piercing a medicament container or vial V1, and a patient needle hub 1020b that terminates in a patient needle or patient cannula 1022b. A hollow tubing 1010 extends between cartridge needle hub 1020a and patient25879 needle hub 1020b and connects the two components to create a fluid path P1 from cartridge cannula 1022a to patient cannula 1022b as shown in FIG.1A.

[0023] The pressure drop in a fluid pipe or tubing assembly may be governed by the Hagen Poiseuille equation show below: where ^^ is L is Length of the pipe, Q is Volumetric Flow rate, R is Radius ofthe pipe (or , Pressure difference between two ends. It will be appreciated from this equation that radius has the highest impact on pressure drop and that increasing the radius of the tubing may substantially reduce pressure drop.

[0024] For the present purposes, total pressure drop in the fluid path may be calculated as: where Pc to the cartridge cannula, and Tu refers to thetubing connecting both cannulas. From this equation, it is apparent that several options are available to reduce the pressure drop and the corresponding injection force. For example, modifying one or more of the cannulas may achieve certain gains, but involves changing multiple parts and complex capital equipment. Alternatively, increasing the tubing diameter may have a large impact on the pressure drop. Specifically, the tubing may be modified without altering the remaining structure of the tubing assembly (e.g., with modifying the cannulas).

[0025] Turning to FIG.1C, in a first embodiment, tubing 1100 may be provided that has a central portion 1110, two tapered portions 1115a,1115b and two terminal portions 1116a,1116b, with a continuous lumen L1 extending between terminal portions 1116a,1116b. As shown, tubing 1100 maybe between 40 mm and 65 mm (e.g., between 50 mm and 60 mm, or approximately 56 mm) in length from the end of terminal portion 1116a to the end of terminal portion 1116b. Tubing 1100 may be configured in a such way that it has a larger diameter at central portion 1110 and smaller diameters at the terminal portions 1116a,1116b. In some examples, central portion 1110 has an inner diameter of approximately 0.5 mm. In some examples, terminal portions 1116a,1116b have the same inner diameter of approximately 0.29 mm. It will be understood that the terminal portions 1116a,1116b may instead have unequal inner diameters, if desired. The tapered portions 1115a,1115b may transition the tubing 1100from the relatively larger inner diameter at central portion 1110 to the relatively smaller diameter at terminal portions 1116a,1116b. In at least some examples, tapered portions 1115a,1115b may be between 2 mm and 8 mm in length, and may transition the inner diameter (i.e., the diameter of the lumen) from 0.5 mm to 0.29 mm.

[0026] In some examples, tubing 1100 may be formed using molding techniques, such as dip molding. Specialized extrusion techniques, such as bump extrusion techniques, may also be used. In some examples, tubing 1100 may be formed of one or more materials, including various polymers or thermoplastic elastomers (TPE). FIG.2 is a chart showing certain dimensions of components of an exemplary injector system that include a cartridge, plunger, cartridge needle, patient needle, and proposed tubing dimensions in the last two rows.

[0027] In a variation of this embodiment, tubing 1200 may be extruded and a secondary operation may be performed to create a shape that has a gradually increasing inner diameter between two sections following by a gradually decreasing inner diameter. In the example shown in FIGS.3-5, tubing 1200 may be divided into three portions at locations 12-1, 12-2 and 12-3, and the tubing 1200 may be connected to a cartridge needle hub 1220a that terminates in a cartridge needle or cartridge cannula 1222a, and a patient needle hub 1220b that terminates in a patient needle or patient cannula 1222b. FIG.5 is a chart showing certain dimensions of examples of such a tubing. As shown, it may be difficult to achieve consistent dimensions (e.g., tapering) using this secondary operation. Without being bound to any particular theory, it is believed that initial testing reveals that the use a varying-diameter tube reduced the injection force by 25%.

[0028] In another embodiment, shown in FIG.6, tubing assembly 1600 including a large diameter tubing 1610 having a constant inner diameter from one end to the other. The inner diameter of tubing 1610 may be similar to the central portions described above for other embodiments (e.g., between 0.4 mm and 0.6 mm, or about 0.5 mm) and the outer diameter may be between 1.6 mm and 2.0 mm, or about 1.74 mm. Two molded connectors 1620 may be coupled to opposing ends of tubing 1610 and configured to receive ends of the tubing. In some examples, molded connectors 1620 may be friction fit onto tubing 1610, although other coupling means are possible. As shown in FIGS.7A-7B, each connector 1620 may include an enlarged section 1622, a tapered section 1624 and a narrowed section 1626. Enlarged section 1622 may have a first inner diameter, D1, configured to receive the outer diameter of tubing 1610 (e.g., enlarged section 1622 may define an inner diameter of approximately 1.8 mm). Tapered section1624 may have a series of gradually decreasing inner diameters D2 that reduce the inner diameter to an inner diameter D3 of narrowed section of approximately 0.28 mm. In some examples, inner diameters D2 in the tapered section begin with an inner diameter of 1.8 mm and linearly decrease to an inner diameter for 0.28 mm. Non-linear transitions are also possible in the tapered sections. Connectors 1620 may be coupled to ends of tubing 1610 and a cannula may be disposed within the narrowed section 1626 of each connector, one to the patient and another to the vial. Without being bound to any particular theory, it is believed that initial testing reveals that the use of connectors in this manner reduced the injection force by approximately 40%.

[0029] FIG.8 shows a system for empirically testing the various tubing assemblies. In this example, various tubings were tested at a constant rate on an INSTRON® machine and the force output was measured utilizing BLEF test setup. In one example, the test speed was 4.5 mm / min or equivalent to 1.2 mL / minute, and the test fluid was N10 (mineral oil) with a viscosity of ~19cP at 20 degrees Celsius. Cartridges were filled to 5 mL. Although the test fluid was N10 with a viscosity of approximately 19 cP, substances contemplated for use with tubing according to the present disclosure may vary. In some examples, substances to be used with the present disclosure may have a viscosity of 0-5 cP, 5-10 cP, 10-15 cP, 15-20 cP, 20-25 cP, 25-30 cP, 30- 35 cP, 35-40 cP, 40-45 cP, 45-50 cP, 50-55 cP, 55-60 cP, 60-65 cP, 65-70 cP, 70-75 cP, 75-80 cP, or 80-90 cP, 90-100 cP, or 100 cP or more. These substances may be administered at 15-20 degrees C, 20-25 degrees C, or 25 or more degrees C.

[0030] FIG.9 illustrates results according to the tested protocol. Several curves are shown illustrating the force in Newtons against the displacement in mm for three different sets. Curve 1900 represents the baseline tubing having a constant diameter, which shows a measured force between 90N and 100N. Curve 1910 represents the first embodiment in which a tubing is manufactured to include varying diameters according to the embodiments described with respect to FIGS.1C-5, and it shows a decrease in the force of approximately 25%. Curve 1920 represents the second embodiment in which a tubing is used in conjunction with molded connectors according to the embodiments described with respect to FIGS.6-7C, and a decrease in the force of approximately 40% was observed.

[0031] It is to be understood that the embodiments described herein are merely illustrative of the principles and applications of the present disclosure. For example, the materials and configurations of the tube may be varied. Moreover, certain components or steps of a method of using the device are optional, and the disclosure contemplates various configurations andcombinations of the steps disclosed herein. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present disclosure as defined by the appended claims.

[0032] It will be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.

Claims

CLAIMS 1. A tubing assembly for an injection device comprising: a tubing having a first end and a second end, the tubing defining a lumen from the first end to the second end, the tubing having a first terminal portion, a first tapered portion, a central portion, a second tapered portion and a second terminal portion.

2. The tubing assembly of claim 1, wherein the central portion has an inner diameter of 0.5 mm.

3. The tubing assembly of claim 1, wherein the first terminal portion and the second terminal portion have a same inner diameter.

4. The tubing assembly of claim 1, wherein the first terminal portion and the second terminal portion both have an inner diameter of 0.29 mm.

5. The tubing assembly of claim 1, wherein the first tapered portion is disposed between the first terminal portion and the central portion, and the second tapered portion is disposed between the second terminal portion and the central portion.

6. The tubing assembly of claim 1, wherein the tubing is between 40 mm and 65 mm in length from the first end to the second end.

7. The tubing assembly of claim 1, wherein the tubing is formed of a polymer.

8. The tubing assembly of claim 1, wherein the tubing is formed of a thermoplastic elastomer.

9. A delivery system comprising: the tubing assembly of claim 1; a first cannula coupled to the first end of the tubing; and a second cannula coupled to the second end of the tubing.

10. A tubing assembly for an injection device comprising: a tubing having a first end and a second end, the tubing defining a lumen having a constant inner diameter and a constant outer diameter from the first end to the second end; a first connector coupled to the first end, the first connector having a first enlarged section, a first tapered section and a first narrowed section; and a second connector coupled to the second end, the second connector having a second enlarged section, a second tapered section and a second narrowed section.

11. The tubing assembly of claim 10, wherein the first connector and the second connector have equal dimensions.

12. The tubing assembly of claim 10, wherein the first connector is configured to accept the outer diameter of the first end of the tubing, and the second connector is configured to accept the outer diameter of the second end of the tubing.

13. The tubing assembly of claim 10, wherein the first narrowed section and the second narrowed section have a same inner diameter.

14. The tubing assembly of claim 10, wherein the first narrowed section and the second narrowed section have an inner diameter of 0.28 mm.

15. The tubing assembly of claim 10, wherein the first tapered section is disposed between the first enlarged section and the first narrowed section, and the second tapered section is disposed between the second enlarged section and the second narrowed section.

16. The tubing assembly of claim 10, wherein the first enlarged section and the second enlarged section have a same inner diameter.

17. The tubing assembly of claim 10, wherein the first enlarged section and the second enlarged section have an inner diameter of 1.8 mm.

18. A delivery system comprising:the tubing assembly of claim 10; a first cannula coupled to the first narrowed section of the first connector; and a second cannula coupled to the second narrowed section of the second connector.

Images