Hollow curved superelastic medical needle and method

• US 20060129101A1
• Filed: 11/17/2005
• Published: 06/15/2006
• Est. Priority Date: 12/09/1998
• Status: Abandoned Application

• Current Assignee: REX Medical LP
• Original Assignee: REX Medical LP
• Inventors: McGuckin, James F. Jr.
• Application Number:
  US11/281,151
• Publication Number:
  US 20060129101A1
• Time in Patent Office: Days
• US Class Current: 604/164.10
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61B 17/3478 Endoscopic needles, e.g. for infusion biopsy needles A61B10/0233; catheters with injection needles A61M25/0067
• CPC Class Codes: A61B 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61M 2025/0007 Epidural catheters
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 25/0041 pre-formed, e.g. specially adapted to fit with the anatomy of body channels urethral catheters A61F2/04
• CPC Class Codes: A61M 25/0043 characterised by structural features
• CPC Class Codes: A61M 25/06 Body-piercing guide needles or the like
• CPC Class Codes: A61M 25/0606 "Over-the-needle" catheter assemblies, e.g. I.V. catheters

Abstract

A needle assembly 10 compromising an infusion needle 11 that includes a needle cannula 13 made of a superelastic material such as Nitinol. The needle cannula is cold-worked or heat annealed to produce a preformed bend 16 that can be straightened within passageway 21 of a coaxial outer cannula 12 for introduction into the body of a patient. Upon deployment from the outer cannula, the needle cannula substantially returns to the preformed configuration for the introduction or extraction of materials at areas lateral to the entry path of the needle assembly. The needle assembly can compromise a plurality of needle cannulae than can be variably arranged or configured for attaining a desired infusion pattern.

Claims

1. A needle assembly comprising an infusion needle having a passsageway and at least one needle cannula having a distal tip, at least one of said cannula, while in an unconstrained configuration having at least one preformed bend and being constrainable to a second configuration whereby upon release of external constraint, said cannula substantially returns to the unconstrained configuration.

2. The needle assembly of claim 1, wherein the constrained configuration is substantially straight.

3. The needle assembly of claim 1, further comprising a coaxial outer cannula for constraining the cannula with preformed bends into the second configuration.

4. The needle assembly of claim 1 wherein the preformed bend cannula comprises a superelastic material.

5. The needle assembly of claim 4 wherein the superelastic material includes a Ni—

Ti alloy.

6. The needle assembly of claim 4 whereby the preformed bend is induced by mechanical deformation such that the superelastic material includes a martensitic crystalline structure, while non-mechanically deformed portions of the needle cannula comprise a substantially austenitic crystalline structure.

7. The needle assembly of claim 1 further comprising an inner needle introducer stylet having a stylet shaft which is insertable into the passageway of the infusion needle.

8. The needle assembly of claim 1 wherein the stylet shaft comprises a flexible polymeric material.

9. The needle assembly of claim 1 wherein the infusion needle includes a needle cannulae.

10. The needle assembly of claim 9 wherein the plurality of needle cannulae radiate outward from a proximal cannula forming a multiple needle assembly.

11. The needle assembly of claim 9 wherein the multiple needle assembly includes both at least one proximally-located needle and at least one distally-located needle.

12. The needle assembly of claim 11 further including a coaxial outer cannula for constraining the preformed and bent one needle cannula into the second configuration, the outer cannula having at least one side hole for deployment of at least one of the proximally located needles therethrough.

13. The needle assembly of claim 11 further comprising an introducer cannula for selectively exposing side holes for deployment of a proximally located needle.

14. The needle assembly of claim 1 wherein the infusion needle further comprises a plane indicator for indicating the direction of a preformed bend of the needle cannula.

19. The needle assembly of claim 4 whereby the preformed bend is induced by mechanical deformation of the needle cannula such that the superelastic material of the at least one preformed bend includes a martensitic crystalline structure, while non-mechanically deformed portions of the needle cannula comprise a substantially austenitic crystalline structure.

20. The needle assembly of claim 14 wherein the infusion needle and coaxial outer cannula are interconnected by a coaxial handle.

15. A needle assembly comprising:

(a) an infusion needle comprising at least one needle cannula made of a superelastic material, having at least one preformed bend while in its unconstrained configuration; and

(b) a coaxial outer cannula having a distal end and passageway therethrough, the infusion needle being adapted to be disposed inside the passageway of the coaxial outer cannula to constrain the infusion needle into the second configuration;

(c) the infusion needle being slidably deployable from the distal end of coaxial outer cannula whereby at release of constraining forces, the at least one needle cannula substantially returns to the unconstrained configuration.

16. The needle assembly of claim 15 wherein the distal end of the coaxial outer cannula includes a sharpened tip adapted for the penetration of tissue.

17. The needle assembly of claim 15 wherein the coaxial outer cannula further includes an outer cannula introducer stylet insertable into the passageway of the coaxial outer needle such that the coaxial outer needle and an outer cannula introducer stylet comprise an outer needle assembly adapted for insertion into the body of a patient.

18. The needle assembly of claim 15 wherein the superelastic material includes a Ni—

Ti alloy.

21. A needle assembly comprising:

an infusion needle having a plurality of needle cannulae each having a distal tip, the plurality of needle cannulae while in their unconstrained configuration having a preformed bend with an angle within a range from 40 to 90°

, the preformed bends being mechanically-induced martensite with straight portions of said inner hollow cannula comprised of austenitic state Ni—

Ti alloy, the plurality of needle cannulae constrainable to a second configuration that is substantially straight, whereby upon release of external constraining forces, the plurality of needle cannulae substantially return to their unconstrained configuration, the infusion needle comprising a Ni—

Ti alloy, the preformed bends of the plurality of needle cannulae induced by mechanically deforming the needle cannula, each preformed bend includes a martensitic crystalline structure, while non-mechanically deformed portions of the needle cannulae comprise a substantially austenitic crystalline structure;

a coaxial outer cannula having a distal end and passageway therethrough, the infusion needle adapted to be disposed thereinside the passageway of the coaxial outer cannula to constrain the infusion needle into the second configuration;

the infusion needle being slidably deployable from the distal end of coaxial outer cannula whereby at release of constraining forces the plurality of needle cannulae substantially return to their unconstrained configuration;

an inner needle introducer stylet having a stylet shaft, the stylet shaft being insertable into the passageway of the infusion needle;

and an outer cannula introducer stylet that is insertable into the passageway of the coaxial outer needle such that the coaxial outer needle and outer cannula introducer stylet comprise an outer needle assembly adapted for insertion into the body of a patient.