Ophthalmic cannula insertion tool and method

• US 20060089607A1
• Filed: 10/22/2004
• Published: 04/27/2006
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Medical Instrument Development Laboratories, Inc.
• Original Assignee: Medical Instrument Development Laboratories, Inc.
• Inventors: Chen, David E.
• Granted Patent: US 7,604,647 B2
• Time in Patent Office: Days
• US Class Current: 604/264
• CPC Class Codes: A61B 17/34 Trocars; Puncturing needles pointed biopsy instruments A61B10/0233; devices for piercing the ear-lobes A44C7/001; seals or hemostasis valves A61M39/06
• CPC Class Codes: A61B 17/3421 Cannulas
• CPC Class Codes: A61B 17/3496 Protecting sleeves or inner probes; Retractable tips for protecting body piercing guide needles A61M25/0612
• CPC Class Codes: A61F 9/007 Methods or devices for eye surgery
• CPC Class Codes: A61M 2005/3228 the needle being retracted by a member protruding laterally through a slot in the barrel, e.g. double-ended needles

Abstract

A cannula insertion tool having a needle movable between a retracted position and an extended position. In some embodiments, the needle can be retracted within the periphery of a handle of the insertion tool when not in use to protect the needle. When the needle is needed for surgical use, the needle can be extended at least partially beyond the outer periphery of the handle. The needle can be coupled to a slide movable relative to the handle between the retracted position and the extended position. The slide can be secured in each position to prevent unintentional movement of the slide. A cannula can be positioned on the needle when the needle is in the retracted position, and can be retained upon the needle by a member extending toward the cannula.

Claims

1. An ophthalmic trocar comprising:

a handle having a top surface and a bottom surface, the handle including

a body portion;

a pair of arms extending from the body portion in a longitudinal direction, the arms at least partially defining a longitudinally extending aperture; and

a rib on each arm;

a slide positioned between the pair of arms and movable along the ribs in the longitudinal direction between a retracted position and an extended position; and

a needle coupled to the slide and movable along with the slide between the retracted position and the extended position, the needle positioned substantially entirely within an outer periphery of the handle in the retracted position, at least a portion of the needle extending beyond the periphery of the handle in the extended position.

2. The ophthalmic trocar of claim 1, wherein the slide is interlocked with the rib in the retracted position of the slide to retain the slide in the retracted position.

3. The ophthalmic trocar of claim 2, wherein the slide has a projection releasably engagable with a recess in the rib to retain the slide in the retracted position.

4. The ophthalmic trocar of claim 3, wherein at least one of the projection and recess has a ramped surface to allow movement of the slide out of the retracted position by movement of the arms.

5. The ophthalmic trocar of claim 1, further comprising a projection extending from the handle into the elongated aperture, the projection positioned to block removal of a cannula positioned on the needle when the slide is in the retracted position.

6. The ophthalmic trocar of claim 1, wherein the slide is interlocked with the handle in the extended position of the slide to retain the slide in the extended position.

7. The ophthalmic trocar of claim 6, further comprising a projection extending from each arm into engagement with a respective recess on the slide when the slide is in the extended position.

8. The ophthalmic trocar of claim 7, wherein the slide is interlocked with the rib in the retracted position of the slide to retain the slide in the retracted position.

9. The ophthalmic trocar of claim 8, further comprising a projection extending from the slide into engagement with a recess on the handle when the slide is in the retracted position.

10. The ophthalmic trocar of claim 9, wherein the arms are elastically deformable to release the slide from the retracted position.

11. A method of inserting a ophthalmic cannula into an eyeball, the method comprising:

providing a trocar having a cannula positioned on a needle of the trocar;

sliding the needle from a retracted position to an extended position relative to a handle of the trocar, the needle being substantially entirely contained within a periphery of the handle in the retracted position, at least a portion of the needle extending beyond the periphery of the handle in the extended position;

retaining the needle in the extended position; and

inserting the needle and the cannula into an eyeball.

12. The method of claim 11, further comprising resisting movement of the needle from the retracted position to the extended position with an interlocking engagement between a slide coupled to the needle and the handle.

13. The method of claim 12, wherein sliding the needle from the retracted position to the extended position further comprises forcing the slide to disengage the interlocking engagement.

14. The method of claim 13, wherein forcing the slide includes forcing a portion of the slide against a portion of the handle to cause a part of the handle to elastically deform until the slide is disengaged from the interlocking engagement.

15. The method of claim 11, wherein locking the needle in the extended position comprises establishing an interlocking engagement between a slide coupled to the needle and the handle.

16. The method of claim 15, further comprising driving a ramped surface of the slide against the handle to elastically expand a portion of the handle.

17. The method of claim 11, further comprising blocking the cannula from removal from the needle with a projection extending from the handle while the needle is in the retracted position.

18. A surgical instrument comprising:

a trocar including

a handle having an outer periphery and a projection extending from the handle;

a slide coupled to the handle for sliding movement relative to the handle; and

a needle coupled to the slide and movable with the slide between an extended position and a retracted position, the needle contained substantially entirely within the outer periphery of the handle when in the retracted position, at least part of the needle extending from the outer periphery of the handle in the extended position; and

a cannula positioned on the needle, the projection extending to a position in which the projection blocks removal of the cannula from the needle when the needle is in the retracted position.

19. The surgical instrument of claim 18, wherein the handle has an elongated aperture and the slide moves within the elongated aperture to place the needle in the extended and retracted positions.

20. The surgical instrument of claim 19, wherein the projection extends into the elongated aperture.

21. The surgical instrument of claim 19, further comprising a first interlocking engagement between the handle and the slide, the first interlocking engagement preventing movement of the slide relative to the handle to retain the needle in the retracted position.

22. The surgical instrument of claim 21, wherein the slide can be forced relative to the handle to disengage the slide from the first interlocking engagement by elastically deforming a portion of the handle.

23. The surgical instrument of claim 21, further comprising a second interlocking engagement between the handle and the slide, the second interlocking engagement preventing movement of the slide relative to the handle to retain the needle in the extended position.