Catheter assembly

• US 20080243116A1
• Filed: 09/20/2007
• Published: 10/02/2008
• Est. Priority Date: 09/21/2006
• Status: Abandoned Application

• Current Assignee: Cathrx Ltd
• Original Assignee: Cathrx Ltd
• Inventors: Anderson, Neil L.
• Application Number:
  US11/903,415
• Publication Number:
  US 20080243116A1
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/1425 Needle
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61N 1/06 for high-frequency therapy
• CPC Class Codes: C08L 2201/12 Shape memory

Abstract

A catheter sheath 10 includes an electrical lead 12 carrying a plurality of electrical conductors 16. A sleeve 20 is co-axially arranged about the electrical lead 12. At least one of a distal end of the lead 12 and a distal end of the sleeve 20 defines a plurality of displaceable petals 22, the petals 22 being displaceable between a first, inoperative position in which the petals 22 extend parallel to a longitudinal axis of the sleeve 20 and a second, operative position in which the petals 22 lie transversely to the longitudinal axis of the sleeve 20. At least one of the petals 20 carries at least one electrode 28, the, or each, electrode 28 being in electrical connection with a group of the conductors 16 of the lead 12.

Claims

1. A catheter sheath comprising:

an electrical lead carrying a plurality of electrical conductors; and

a sleeve co-axially arranged about the electrical lead, at least one of a distal end of the lead and a distal end of the sleeve defining a plurality of displaceable petals, the petals being displaceable between a first, inoperative position in which the petals extend parallel to a longitudinal axis of the sleeve and a second, operative position in which the petals lie transversely to the longitudinal axis of the sleeve; and

at least one of the petals carrying at least one electrode, the at least one electrode being in electrical connection with a group of the conductors of the lead.

2. The catheter sheath of claim 1 in which the petals are displaceable between their inoperative position and their operative position by relative movement between the electrical lead and the sleeve.

3. The catheter sheath of claim 1 in which the electrical lead is tubular defining a lumen and the electrical conductors are embedded in a wall of the electrical lead.

4. The catheter sheath of claim 1 in which the distal end of the sleeve extends beyond the distal end of the lead, the distal end of the sleeve defining the petals.

5. The catheter sheath of claim 4 in which the sleeve is of a plastics material of a first stiffness along its length and a more flexible material in a region of deflection in which region the sleeve is able to bend.

6. The catheter sheath of claim 5 which includes a crown portion of a plastics material of a different stiffness to the flexible material of the region of deflection, the crown portion being attached to a distal end of the electrical lead and projecting distally of the distal end of the electrical lead, the crown portion defining a plurality of secondary leaves, each secondary leaf being in register with one of the petals of the sleeve.

7. The catheter sheath of claim 6 in which the crown portion is arranged within the sleeve and the electrodes are carried on inner surfaces of the secondary leaves of the crown portion, each secondary leaf being fast with its associated petal of the sleeve.

8. The catheter sheath of claim 4 in which the sleeve is of a plastics material of a first stiffness along its length, a more flexible material in a region of deflection in which region the sleeve bends and in which the sheath includes a crown portion of a plastics material of a different stiffness to the flexible material of the region of deflection attached to a distal end of the region of deflection, the crown portion defining the petals the sleeve.

17. A catheter assembly which includes

a catheter sheath as claimed in claim 1;

and

a stylet received in the lumen of the electrical lead.

18. The assembly of claim 17 in which a distal end of the stylet carries an electrode.

19. The assembly of claim 18 in which, when the petals of the catheter sheath are in their closed position, the petals underlie the button electrode, the stylet being displaceably arranged relative to the catheter sheath.

20. The assembly of claim 18 in which the electrode is mounted on the distal end of the stylet via a force absorbing element.

21. The assembly of claim 18 in which the stylet is a steering shaft for steering a distal part of the catheter sheath.

22. The assembly of claim 21 in which the steering shaft defines a passage through which conductors for the electrode are able to pass.

23. The assembly of claim 18 in which the electrode is a button electrode.

24. The assembly of claim 18 in which the electrode is a needle electrode.

25. The assembly of claim 17 in which a distal end of the electrical lead carries a distal electrode, the sleeve defining the petals and the petals surrounding the distal electrode when the petals are arranged in their closed configuration.

9. A method of fabricating a catheter sheath, the method including

providing an electrical lead carrying electrical conductors;

providing a sleeve and arranging the sleeve co-axially with respect to the electrical lead, at least one of the sleeve and the lead defining a plurality of discrete petals at its distal end;

forming at least one electrode on at least one of the petals; and

electrically connecting the at least one electrode to a group of the conductors.

10. The method of claim 9 which includes rendering the group of conductors mechanically fast with its associated petal.

11. The method of claim 9 in which the electrical lead is tubular defining a lumen with the conductors being embedded in a wall of the electrical lead, the method including removing material of a distal part of the wall of the electrical lead to expose distal regions of the conductors which form free parts of the conductors.

12. The method of claim 11 which includes arranging the parts of the conductors to extend distally from the distal end of the electrical lead.

13. The method of claim 12 which includes, after exposing the parts of the conductors, stripping insulation from the exposed parts of the conductors.

14. The method of claim 9 which includes arranging the sleeve about the electrical lead.

15. The method of claim 9 which includes mounting a crown portion on the distal end of the electrical lead, the crown portion being of a material having a different stiffness from that of material of a region of deflection of the sleeve, in which region the sleeve bends, and the crown portion defining a plurality of secondary leaves.

16. The method of claim 15 which includes bonding each secondary leaf to an associated petal of the sleeve and forming at least one electrode on an inner surface of each of at least some of the secondary leaves.