Subcutaneous Infusion Device and Method including Tapered Cannula

• US 20080103450A1
• Filed: 10/31/2006
• Published: 05/01/2008
• Est. Priority Date: 10/31/2006
• Status: Active Grant

• Current Assignee: Smiths Medical ASD, Inc. (Smiths Group International Holdings Ltd.)
• Original Assignee: Smiths Medical ASD, Inc. (Smiths Group International Holdings Ltd.)
• Inventors: Bresina, Timothy, Faust, Mark, Marrs, James
• Granted Patent: US 7,993,306 B2
• Time in Patent Office: Days
• US Class Current: 604/174
• CPC Class Codes: A61M 2005/1581 Right-angle needle-type devices
• CPC Class Codes: A61M 2005/1587 suitable for being connected to an infusion line after insertion into a patient
• CPC Class Codes: A61M 5/158 Needles for infusions; Accessories therefor, e.g. for inserting infusion needles, or for holding them on the body

Abstract

A site for a subcutaneous infusion device includes a base positionable relative to skin of a patient, and a cannula extending from the base and configured to be introduced into a subcutaneous layer of skin of the patient at a generally ninety-degree angle with respect to the skin using a needle. The cannula includes first and second ends and defines a bore extending from the first end to the second end, the first end being coupled to the base. The cannula includes a tapered wall portion formed between the first and second ends and extending from adjacent to the base towards the second end of the cannula, the tapered wall portion being tapered from a greater wall thickness to a lesser wall thickness as the tapered wall portion extends from the base towards the second end.

Claims

1. A site for a subcutaneous infusion device, the site comprising:

a base positionable relative to skin of a patient; and

a cannula extending from the base and configured to be introduced into a subcutaneous layer of skin of the patient at a generally ninety-degree angle with respect to the skin using a needle;

wherein the cannula includes first and second ends and defines a bore extending from the first end to the second end, the first end being coupled to the base; and

wherein the cannula includes a tapered wall portion formed between the first and second ends and extending from adjacent to the base towards the second end of the cannula, the tapered wall portion being tapered from a greater wall thickness to a lesser wall thickness as the tapered wall portion extends from the base towards the second end.

2. The site of claim 1, wherein the tapered wall portion is positioned outside the base.

3. The site of claim 1, wherein a difference in diameter between the greater wall thickness and the lesser wall thickness is approximately 1 millimeter.

4. The site of claim 1, wherein a length of the cannula from the tapered wall portion to the second end is approximately less than 9 millimeters.

5. The site of claim 4, wherein the length of the cannula from the tapered wall portion to the second end is approximately 6 millimeters.

6. The site of claim 5, wherein the length of the cannula from the tapered wall portion to the second end is approximately 3 millimeters.

7. The site of claim 1, wherein the first end of the cannula includes a tapered top side opening into a reservoir defined by the base.

8. The site of claim 1, wherein the first end of the cannula includes a flanged portion having a bottom side configured to engage a bottom surface in a cavity of the base, and a tapered top side opening into the cavity, and wherein the cannula extends through a central aperture of the base generally perpendicular to the base such that the second end of the cannula is positioned outside the base.

9. The site of claim 1, further comprising:

a single, unitary diaphragm coupled to the base, the single diaphragm including a closed end, an open end, and a sidewall, and the single diaphragm defining an internal reservoir in fluid communication with the cannula through the open end;

wherein the single diaphragm is pierced by the needle through the upper end to introduce the cannula into the subcutaneous layer of skin of the patient; and

wherein the single diaphragm is pierceable through the sidewall to access the internal reservoir to deliver a substance to the patient through the cannula.

10. An infusion device, comprising:

a site including a base, a cannula extending from the base, and a seal in fluid communication with the cannula for delivering a substance through the seal and into the cannula, the cannula including a first portion that is coupled to the base, a second portion extending from the first portion, and a third portion this is a free end, wherein the second portion includes a wall portion that is tapered from a greater wall thickness to a lesser wall thickness as the wall portion extends from the first portion to the third portion; and

a set including a first member including a needle, and a second member defining an aperture configured to accept the site, wherein the first member is slideable relative to the second member from an unlocked to a locked position, and wherein in the locked position the needle extends into the aperture and through a portion of the seal of the site to deliver the substance to the site.

11. The device of claim 10, wherein the first portion of the cannula includes a flanged portion having a bottom side configured to engage a bottom surface in a cavity of the base, and a tapered top side opening into the cavity, and wherein the cannula extends through a central aperture of the base generally perpendicular to the base such that the second and third portions of the cannula are positioned outside the base.

12. The device of claim 10, further comprising:

a single, unitary diaphragm coupled to the base, the single diaphragm including a closed end, an open end, and a sidewall, and the single diaphragm defining an internal reservoir in fluid communication with the cannula through the open end;

wherein the single diaphragm is pierced by the needle through the upper end to introduce the cannula into the subcutaneous layer of skin of the patient; and

wherein the single diaphragm is pierceable through the sidewall to access the internal reservoir to deliver a substance to the patient through the cannula.

13. The device of claim 10, wherein the cannula is configured to be introduced into a subcutaneous layer of skin of the patient at a generally ninety-degree angle with respect to the skin using a needle.

14. A method of forming a cannula for a site of an infusion device, the method comprising:

forming a longitudinal body including first and second ends and defining a bore extending therethrough;

defining a first portion at a first end of the body configured to be coupled to a base of a site;

defining a tapered wall portion of the body including a first wall thickness adjacent to the first portion and a second wall thickness adjacent to a third portion of the body including a free end, the first wall thickness being greater than the second wall thickness, and the tapered wall portion being tapered as the tapered wall portion extends from the first wall thickness to the second wall thickness.

15. The method of claim 14, further comprising positioning the tapered wall portion outside the base.

16. The method of claim 14, further comprising forming a difference in diameter between the first wall thickness and the second wall thickness to be approximately 1 millimeter.

17. The method of claim 14, further comprising forming a length of the cannula from the tapered wall portion to the second end to be less than 9 millimeters.

18. The method of claim 17, further comprising forming the length of the cannula from the tapered wall portion to the second end to be approximately 6 millimeters.

19. The method of claim 17, further comprising forming the length of the cannula from the tapered wall portion to the second end to be approximately 3 millimeters.

20. The method of claim 14, further comprising forming a tapered top side opening in the first end of the cannula extending into a reservoir defined by the base.