Bidirectional steering catheter

• US 5,715,817 A
• Filed: 06/07/1995
• Issued: 02/10/1998
• Est. Priority Date: 06/29/1993
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Stevens-Wright, Debbie E., Cuscuna, Dino F., Fagan, John R., Karakozian, Sarkis
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US08/478,206
• Time in Patent Office: 979 Days
• Field of Search: 128/642, 607/122, 604/95, 606/41
• US Class Current: 600/373
• 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 2017/003 Steerable
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/00946 slidable
• CPC Class Codes: A61B 2018/00952 rotatable
• CPC Class Codes: A61M 2025/015 Details of the distal fixation of the movable mechanical means
• CPC Class Codes: A61M 2025/0161 wherein the distal tips have two or more deflection regions
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: A61M 25/0136 Handles therefor
• CPC Class Codes: A61M 25/0141 having flexible regions as a result of using materials with different mechanical properties
• CPC Class Codes: A61M 25/0144 having flexible regions as a result of inner reinforcement means, e.g. struts or rods
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires

Abstract

A bidirectional steering catheter comprising a distal electrode assembly, a flexible tip assembly, an elongated shaft having a central lumen running the length of the shaft, and a handle/actuator. A plurality of ring electrodes are attached to the surface of the flexible tip assembly. Signal wires running the length of the catheter are electrically connected to each ring electrode. At least two pull cables having first and second ends extend distally through the central lumen. The first end of each pull cable is attached to the handle/actuator. The second end of each pull cable is attached to the distal electrode assembly, such that the distal electrode assembly may be moved between a first and a second position within a single plane by manipulating the handle/actuator. At least two reinforcement members are located inside the flexible tip assembly. Each reinforcement member has a proximal section, a middle section and a distal section. Each proximal section has a larger diameter than each middle section, thus being stiffer than the middle section. This variable stiffness along the length of the each reinforcement member distributes stresses evenly along the length of the tip assembly.

Claims

1. A bidirectional steering catheter comprising:

a distal electrode assembly having a distal end and a proximal end;

a flexible tip assembly attached to the proximal end of the distal electrode assembly;

an elongated shaft having a distal and proximal end, the distal end of the elongated shaft attached to the flexible tip assembly, and the elongated shaft having a central lumen running the length of the shaft;

a handle/actuator attached to the proximal end of the elongated shaft;

at least two pull cables having first and second ends, each pull cable being attached at its first end to the handle/actuator and extending distally through the central lumen within the elongated shaft and the flexible tip assembly, each pull cable being further attached at its second end to the distal electrode assembly, such that the distal electrode assembly may be moved between a first and a second position within a single plane by manipulating the handle/actuator; and

at least two reinforcement members located inside the flexible tip assembly, wherein each reinforcement member has a proximal section, a middle section and a distal section, the proximal section being of greater stiffness than the middle section, such that the length of each reinforcement member has a variable stiffness that distributes stresses evenly along the length of the tip assembly.

2. The bidirectional steering catheter as in claim 1, further comprising:

a plurality of ring electrodes attached to an outer surface of the flexible tip assembly; and

a plurality of signal wires running the length of the catheter, one signal wire being attached to each ring electrode.

3. The bidirectional steering catheter as in claim 2, wherein the plurality of ring electrodes are raised above the outer surface of the flexible tip assembly, for enhanced electrode contact.

4. The bidirectional steering catheter as in claim 2, wherein the plurality of ring electrodes are convexly shaped for enhanced electrode contact.

5. The bidirectional steering catheter as in claim 2, further comprising a thermistor located within the distal electrode assembly, the thermistor being electrically connected to one of the signal wires.

6. The bidirectional steering catheter as in claim 2, further comprising an electrode cap located at the distal end of the distal electrode assembly, and being electrically connected to one of the signal wires.

7. The bidirectional steering catheter as in claim 1, wherein each pull cable is made from ultra-high molecular weight polyethylene.

8. The bidirectional steering catheter as in claim 1, wherein each pull cable is made from a stranded stainless steel cable.

9. The bidirectional steering catheter as in claim 1, wherein each pull cable is enclosed in a protective sheath.

10. The bidirectional steering catheter as in claim 9, wherein the protective sheath is made from polytetrafluoroethylene.

11. The bidirectional steering catheter as in claim 10, further comprising two pull cable lumens located within the flexible distal assembly, through which the two pull cables are inserted.

12. The bidirectional steering catheter as in claim 1, wherein the proximal and distal sections of each reinforcement member are of equal diameter, whereas the middle section has a smaller diameter, thereby imparting variable stiffness to the flexible tip assembly.

13. The bidirectional steering catheter as in claim 12, wherein each reinforcement member is made from a super-elastic alloy.

14. The bidirectional steering catheter as in claim 13, wherein each reinforcement member is made from Nitinol, a Nickel-Titanium alloy.

15. The bidirectional steering catheter as in claim 13, further comprising two reinforcement lumens located within the flexible tip assembly, through which the two reinforcement members are inserted.

16. The bidirectional steering catheter as in claim 15, wherein the diameter of the proximal and distal sections of each reinforcement member is substantially equal to the diameter of the reinforcement lumen, resulting in a tight fit around the reinforcement member, thereby anchoring the reinforcement member within the reinforcement lumen.

17. A bidirectional steering catheter comprising:

a distal electrode assembly having a distal and a proximal end;

a flexible tip assembly attached to the proximal end of the distal electrode assembly, the flexible tip assembly including a tubular section, through which two reinforcement lumens and two pull cable lumens are embedded, and further including a central lumen running the length of the flexible tip assembly, the central lumen having a plurality of signal wires running through the center thereof;

a plurality of ring electrodes attached to a surface of the flexible tip assembly, each ring electrodes being electrically connected to one of the signal wires;

a distal electrode cap attached to the distal end of the distal electrode assembly and being electrically connected to one of the signal wires;

a thermistor attached to the distal end of the distal electrode assembly and being electrically connected to one of the signal wires;

an elongated shaft having a distal and proximal end, the distal end of the elongated shaft attached to the flexible tip assembly, and the elongated shaft having the central lumen running the length of the shaft;

a handle/actuator attached to the proximal end of the elongated shaft;

two pull cables, each having a first end and a second end, each pull cable being attached at its first end to the handle/actuator and extending distally through the central lumen within the elongated shaft and through the pull cable lumens within the flexible tip assembly, each pull cable further being attached at its second end to the distal electrode assembly, such that the distal electrode assembly may be moved between a first and a second position within a single plane by manipulating the handle/actuator; and

at least two reinforcement members located inside the reinforcement lumens of the flexible tip assembly, wherein each reinforcement member has a proximal section, a middle section and a distal section, the proximal section being of greater stiffness than the middle section, such that the length of each reinforcement member has a variable stiffness that distributes stresses evenly along the length of the tip assembly.

18. The bidirectional steering catheter as in claim 17, wherein the plurality of ring electrodes are raised above the surface of the flexible tip assembly, for enhanced electrode contact.

19. The bidirectional steering catheter as in claim 17, wherein the plurality of ring electrodes are convexly shaped for enhanced electrode contact.

20. The bidirectional steering catheter as in claim 17, wherein each pull cable is enclosed in a protective sheath.

21. The bidirectional steering catheter as in claim 17, wherein the protective sheath surrounding each pull cable is made from polytetrafluoroethylene.

22. The bidirectional steering catheter as in claim 17, wherein the proximal and distal sections of each reinforcement member are of equal diameter, whereas the middle section has a smaller diameter, thereby imparting variable stiffness to the flexible tip assembly.

23. The bidirectional steering catheter as in claim 22, wherein each reinforcement member is made from a super-elastic alloy.

24. The bidirectional steering catheter as in claim 23, wherein each reinforcement member is made from Nitinol, a Nickel-Titanium alloy.

25. The bidirectional steering catheter as in claim 24, wherein the diameter of the proximal and distal sections of each reinforcement member is substantially equal to the diameter of the reinforcement lumen, resulting in a tight fit around the reinforcement member, thereby anchoring the reinforcement member within the reinforcement lumen.