Multiple cannula systems and methods
View Patent ↗The preferred embodiments provide, e.g., a high quality flexible tracheostomy tube assembly including an outer tracheostomy cannula and a disposable, flexible inner cannula. In preferred embodiments, the product provides a single patient use, sterile device.
1. A method for using an insertable multiple cannula assembly, the method comprising:
positioning an outer cannula, the outer cannula having a tip including a stepped portion configured to reduce an outward bulge of a cuff coupled to the outer cannula;
positioning an inner cannula at least partially within the outer cannula;
connecting the inner cannula relative to the outer cannula; and
inflating the cuff coupled to the outer cannula.
2. A method according to claim 1 , wherein connecting the inner cannula relative to the outer cannula includes rotating the inner cannula relative to the outer cannula from an unlocked position to a locked position.
3. A method according to claim 1 , wherein connecting the inner cannula relative to the outer cannula includes rotating a hub of the inner cannula relative to a head of the outer cannula from an unlocked position to a locked position in which at least one protrusion of the inner cannula hub is engaged with at least one ridge of the outer cannula head.
4. A method according to claim 1 , wherein the outer cannula tip is substantially rigid.
5. A method according to claim 1 , wherein the outer cannula tip includes a tapered portion extending from a first end having a first outer diameter to a second end having a second outer diameter larger than the first outer diameter, and a cylindrical portion having a third outer diameter, wherein the stepped portion is defined by a difference between the second outer diameter and the third outer diameter.
6. A method according to claim 5 , wherein the tapered portion and the cylindrical portion of the outer cannula tip have a constant inner diameter.
7. A method according to claim 1 , wherein both the inner cannula and the outer cannula arc substantially flexible.
8. A method for using a medical cannula, the method comprising:
inserting at least a portion of a substantially flexible cannula assembly into a patient, the cannula assembly including (a) and outer cannula having an outer cannula body, an inflatable cuff coupled to the outer cannula body, and a stepped portion configured to reduce an outward bulge of the cuff relative to the outer cannula body and (b) a retractable inner cannula inserted at least partially within and locked to the outer cannula; and
after inserting the cannula assembly including the outer cannula and inner cannula, inflating the cuff coupled to the outer cannula body.
9. A method according to claim 8 , wherein the stepped portion is formed on a tip of the cannula.
10. A method according to claim 9 , wherein the cannula tip is substantially rigid.
11. A method according to claim 8 , wherein locking the inner cannula relative to the outer cannula includes rotating the inner cannula relative to outer cannula from an unlocked position to a locked position.
12. A method according to claim 8 , wherein locking the inner cannula relative to the outer cannula includes rotating a hub of the inner cannula relative to a head of the outer cannula from an unlocked position to a locked position in which at least one protrusion of the inner cannula hub is engaged with at least one ridge of the outer cannula head.
13. A method according to claim 8 , wherein the outer cannula includes a tapered portion extending having a first end with a first outer diameter and a second end with a second outer diameter larger than the first outer diameter, and a cylindrical portion having a third outer diameter, wherein the stepped portion is defined by a difference between the second outer diameter and the third outer diameter.
14. A method according to claim 13 , wherein the tapered portion and the cylindrical portion of the outer cannula have a constant inner diameter.
15. A method for manufacturing a medical cannula assembly, the method comprising:
forming an outer cannula, including:
forming a first cannula portion having a first outer diameter;
forming a second cannula portion having a second outer diameter larger than the first outer diameter of the first cannula portion; and
coupling at least one end of an inflatable cuff to the first cannula portion;
wherein the difference between the second outer diameter of the second cannula portion and the first outer diameter of the first cannula portion forms a stepped portion configured to reduce an outward bulge of the cuff, and
forming an inner cannula configured for insertion into and locking with the outer cannula.
16. A method according to claim 15 , wherein the second cannula portion of the outer cannula tapers from a first end having the second outer diameter to a second end having a third outer diameter smaller than the second outer diameter.
17. A method according to claim 15 , wherein:
the first and second cannula portions of the outer cannula are portions of a cannula tip; and
the method further includes attaching the cannula tip to an elongated cannula body.
18. A method according to claim 15 , wherein:
the first cannula portion of the outer cannula comprises a portion of an elongated cannula body;
the second cannula portion of the outer cannula comprises a portion of a cannula tip; and
the method further includes attaching the cannula tip to the cannula body.
19. A method according to claim 15 , wherein the first and second cannula portions of the outer cannula are portions of an elongated cannula body distinct from a cannula tip.
20. A method according to claim 15 , wherein the first and second cannula portions of the outer cannula are formed integrally.
21. A method according to claim 15 , wherein the stepped portion is configured to reduce an outward bulge of the inflatable cuff, when inflated.