Steerable ultrasound catheter

• US 20050228290A1
• Filed: 04/07/2004
• Published: 10/13/2005
• Est. Priority Date: 04/07/2004
• Status: Active Grant

• Current Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Original Assignee: Ep Medsystems Incorporated (Abbott Laboratories)
• Inventors: Dala-Krishna, Praveen, Byrd, Charles Bryan, Borovsky, Simcha
• Granted Patent: US 7,507,205 B2
• Time in Patent Office: Days
• US Class Current: 600/466
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61B 8/4466 involving deflection of the probe
• CPC Class Codes: A61B 8/4488 the transducer being a phased array

Abstract

Steerable catheters are provided including an elongated flexible member having a proximal end, a distal end and a lumen extending therebetween (i.e., between the proximal end and the distal end). A plurality of electrical cables is bundled together and positioned within the lumen of the flexible member. The cross-section of the bundle of electrical cables is substantially ovular or rectangular so as to be bendable in two approximately opposite directions. Methods of steering such a catheter within a body include advancing the catheter within a body while a first force is applied to the bundle of electrical cables to cause the distal end of the elongate flexible member to form a bend. The catheter is farther advanced within the body while a second, opposite force is applied to the bundle of electrical cables to remove the bend in the distal end.

Claims

1. A catheter comprising:

an elongated tubular member having a proximal end, a distal end and a lumen extending between the proximal end and the distal end; and

a plurality of electrical cables bundled together and located within the lumen of the tubular member, a cross-section of the bundle of cables being substantially ovular or rectangular so as to be selectively bendable in two approximately opposite directions.

2. The catheter of claim 1, further comprising an ultrasound transducer adjacent the distal end of the tubular member, wherein the plurality of electrical cables are coaxial cables and a distal end of the plurality of coaxial cables is connected to the ultrasound transducer.

3. The catheter of claim 2, further comprising a pair of steering cables having proximal and distal ends, the distal ends of the steering cables being connected to the tubular member proximal to the ultrasound transducer, the steering cables extending through the lumen of the elongated tubular member.

4. The catheter of claim 3, further comprising a steering device adjacent the proximal end of the elongated tubular member, the steering device being capable of manipulating the proximal ends of the steering cables thereby causing the distal end of the elongated tubular member to bend.

5. The catheter of claim 1, further comprising at least one steering cable coupled to the distal end of the elongated tubular member and extending proximally to the proximal end of the elongated tubular member, the at least one steering cable being capable of bending the distal end of the elongated tubular member when a pulling force is applied to the steering cable.

6. The catheter of claim 5, wherein the steering cable comprises a first end and a second end, and wherein a pulling force applied to the first end causes the elongated tubular member to bend in a first direction, and a pulling force applied to the second end causes the elongated tubular member to bend in a second direction approximately opposite the first direction.

7. The catheter of claim 1, wherein the catheter is disposable and adapted for single use.

8. The catheter of claim 2, wherein a first section of the elongated tubular member adjacent the ultrasound transducer is more flexible than a second section of the elongated tubular member proximal the first section.

9. The catheter of claim 8, wherein the first section of the elongated tubular member is capable of being bent at a first radius of curvature, and the second section of the elongated tubular member is capable of being bent at a second radius of curvature, wherein the second radius of curvature is greater than the first radius of curvature.

11. The catheter of claim 9, wherein the first radius of curvature is no more than about one inch.

12. The catheter of claim 9, wherein the first radius of curvature is no more than about half an inch.

13. The catheter of claim 9, wherein the second radius of curvature is no more than about three inches.

14. The catheter of claim 9, wherein the second radius of curvature is no more than about two inches.

15. The catheter of claim 9, wherein the second radius of curvature is no more than about one inch.

16. The catheter of claim 9, wherein the second radius of curvature is no more than about half an inch.

17. The catheter of claim 2, further comprising:

an ultrasound transducer adjacent the distal end of the tubular member,

wherein a distal end of the plurality of coaxial cables is connected to the ultrasound transducer, and

wherein a section of the elongated tubular member adjacent the ultrasound transducer comprises;

a hollow cylinder with a proximal end and a distal end and a first aperture and a second aperture, the first and second apertures opposing each other, wherein the steering cable is threaded through the proximal end of the hollow cylinder passing through a lumen of the hollow cylinder, out the first aperture, around an outer circumference of the hollow cylinder, and through the second aperture back into the lumen of the hollow cylinder and out the proximal end; and

a flexible tubular member coaxially fitted over the proximal end of the hollow cylinder.

18. The catheter of claim 1, wherein the plurality of electrical cables are bundled together within a sheath.

19. The catheter of claim 17, wherein ends of the steering cable are connected forming an elongated loop, and

wherein the catheter further comprises a steering device adjacent the proximal end of the elongated tubular member, the steering device being capable of manipulating the elongated loop thereby causing the distal end of the elongated tubular member to bend.

20. The catheter of claim 1, wherein the catheter is an electrophysiology recording catheter further comprising an electrophysiology recording electrode within the catheter, wherein one of the plurality of electrical cables is connected to the electrophysiology recording electrode.

21. The catheter of claim 1, wherein the catheter is an ablation catheter further comprising an ablation electrode within the catheter, wherein one of the plurality of electrical cables is connected to the ablation electrode.

23. The catheter of claim 19, where the lumen of the first cylinder comprises an ovular or rectangular cross-section shaped to receive the bundle of coaxial cables.

24. The catheter of claim 19, wherein the plurality of coaxial cables is bundled together within a sheath.

25. The catheter of claim 19, wherein the proximal end of the bundle of coaxial cables is adapted for connection to an ultrasound machine.

10. The catheter of clam 9, wherein the first radius of curvature is no more than about two inches.

22. A steerable ultrasound catheter comprising:

a transducer array;

a plurality of coaxial cables forming a bundle, the bundle having a proximal end and a distal end, the distal end of the bundle being connected to the transducer array, a cross-section of the bundle being substantially ovular or rectangular so as to be bendable in two approximately opposite directions;

a first cylinder having a first aperture, a second aperture opposing the first aperture, a proximal end with an opening, a distal end with an opening, and a lumen extending between the proximal end and the distal end of the first cylinder, the bundle of coaxial cables being inserted through the opening in the distal end of the first cylinder;

a steering cable threaded through the opening in the proximal end of the first cylinder passing through the lumen of the first cylinder, out the first aperture, around an outer circumference of the first cylinder, and through the second aperture back into the lumen of the first cylinder and back out the opening in the proximal end of the first cylinder;

a second cylinder having a proximal end with an opening, a distal end with an opening, and a lumen extending between the proximal end and the distal end of the second cylinder, wherein the first cylinder is inserted through the opening in the distal end of the second cylinder and the steering cable extends through the lumen of the second cylinder and out the opening at the proximal end of the second cylinder; and

an elongated tubular member that is fitted over the proximal end of the second cylinder and receives the bundle of coaxial cables and the steering cable.

26. A method of imaging an anatomical structure of a mammal comprising:

providing an ultrasound catheter comprising;

an elongated tubular member having a proximal end, a distal end and a lumen extending between the proximal end and the distal end of the elongated tubular member;

an ultrasound transducer carried by the elongated tubular member adjacent the distal end of the elongated tubular member; and

a plurality of coaxial cables bundled together and located within the lumen of the elongated tubular member, a cross-section of the bundle of cables being substantially ovular or rectangular so as to be bendable in two approximately opposite directions;

making an incision in the mammal;

inserting the ultrasound catheter through the incision;

advancing the ultrasound catheter into the anatomical structure by bending the distal end of the elongated tubular member along the longer sides of the ovular or rectangular cross-section of the bundle of cables while pushing the ultrasound catheter forward relative to the incision; and

activating the ultrasound transducer to take a first image of the anatomical structure.

27. The method of claim 26, further comprising bending the distal end of the elongated tubular member along the longer sides of the ovular or rectangular cross-section of the bundle of cables and taking a second image from an angle different from an angle from which the first image was taken.

28. The method of claim 26, further comprising rotating the distal end of the elongated tubular member prior to bending the distal end of the elongated tubular member.

29. A method of steering a catheter within a body, comprising:

advancing the catheter within the body, the catheter comprising;

an elongated tubular member having a proximal end, a distal end and a lumen extending between the proximal end and the distal end of the elongated tubular member; and

a plurality of electrical cables bundled together and located within the lumen of the tubular member, a cross-section of the bundle of electrical cables being substantially ovular or rectangular so as to be selectively bendable in two approximately opposite directions;

applying a first force to the bundle of electrical cables to cause the distal end of the elongated tubular member to form a bend;

advancing the catheter within the body; and

applying a second force to the bundle of electrical cables to remove the bend in the distal end of the elongated tubular member, wherein the second force is substantially opposite the first force.

30. The method of claim 29, wherein the catheter further comprises at least one steering cable coupled to the distal end of the elongated tubular member and extending proximally to the proximal end of the elongated tubular member, the at least one steering cable being capable of bending the distal end of the elongated tubular member when a pulling force is applied to the at least one steering cable, and wherein the first force is applied by applying a pulling force on a first end of the at least one steering cable, and the second force is applied by applying a pulling force on a second end of the at least one steering cable.

31. A steerable catheter comprising:

an elongated tubular member having a proximal end, a distal end, and lumen extending between the proximal end and the distal end of the elongated tubular member;

a steering cable having a first section, a second section, and a third section, the steering cable being threaded through the elongated tubular member such that the first and third sections are adjacent one another and are separated from one another at the second section which forms a loop around the distal end of the elongate tubular member.

32. The steering catheter of claim 31 further comprising a steering element attached to the first and third sections of the steering cable, the steering element being capable of applying a pulling force on the first and third sections independently of one another.

33. The steering catheter of claim 32, wherein a first pulling force applied to the first section bends the catheter in a first direction, and a second pulling force applied to the third section bends the catheter in a second direction approximately opposite the first direction.

34. The steering catheter of claim 31, wherein the first and third sections are intertwined.

35. The steering catheter of claim 31, further comprising a second elongated member within the lumen of the elongated tubular member, wherein the second elongated member comprises a lumen and the first and third sections of the steering cable are located within the lumen.

36. The steering catheter of claim 31, wherein the steering cable comprises a polymer material.

37. An ultrasound catheter comprising:

an elongated tubular member comprising a first section having a first Shore Durometer hardness, a second section distal the first section and having a second Shore Durometer hardness, the second Shore Durometer hardness being less than the first Shore Durometer hardness, and a third section distal the second section and having a third Shore Durometer hardness, the third Shore Durometer hardness being less than the second Shore Durometer hardness; and

an ultrasound transducer mounted on the elongate tubular member adjacent the third section,

wherein the first section of the tubular member is capable of being bent at a first radius of curvature, the second section of the tubular member is capable of being bent at a second radius of curvature, the second radius of curvature being less than the first radius of curvature, and the third section of the tubular member is capable of being bent at a third radius of curvature, the third radius of curvature being less than the second radius of curvature.

39. The catheter of claim 37, wherein the first radius of curvature is no more than about three inches, the second radius of curvature is no more than about two inches, and the third radius of curvature is no more than about one inch.

40. The catheter of claim 37, wherein the first radius of curvature is no more than about two inches, the second radius of curvature is no more than about one inch, and the third radius of curvature is no more than about half an inch.

41. The catheter of claim 37, further comprising a plurality of coaxial cables bundled together and located within a lumen of the tubular member, the cross-section of the bundle of cables being substantially oval or rectangular so as to be preferentially bendable in two approximately opposite directions.

38. The catheter of clam 37, wherein the first radius of curvature is no more than about four inches, the second radius of curvature is no more than about three inches, and the third radius of curvature is no more than about two inches.

42. A catheter comprising:

an elongated tubular member having a proximal end, a distal end and a lumen extending between the proximal end and the distal end of the elongated tubular member; and

a plurality of coaxial cables bundled together and located within the lumen of the elongated tubular member, the bundle of coaxial cables comprising a substantially ovular or rectangular cross-section, wherein the bundle of coaxial cables is twisted along its length so that a distal end of the bundle of coaxial cables is substantially perpendicular to a proximal end of the bundle of cables.

43. The catheter of claim 42, further comprising an ultrasound transducer adjacent the distal end of the elongated tubular member, wherein the distal end of the plurality of coaxial cables is connected to the ultrasound transducer.

44. The catheter of claim 42, further comprising:

a first steering cable coupled to the distal end of the bundle of coaxial cables and extending proximally to the proximal end of the elongated tubular member, the first steering cable being capable of bending the distal end of the elongated tubular member along a first plane that is substantially perpendicular to the distal end of the bundle of coaxial cables when a pulling force is applied to the first steering cable; and

a second steering cable coupled to a region of the bundle of coaxial cables proximal the distal end of the bundle of cables, the region being substantially perpendicular to the distal end of the bundle of coaxial cables, the second steering cable being capable of bending the distal end of the elongated tubular member along a second plane that is substantially parallel to the distal end of the bundle of coaxial cables when a pulling force is applied to the second steering cable.

45. The catheter of claim 44, wherein the first steering cable comprises a first end and a second end, and wherein a pulling force applied to the first end of the first steering cable causes the elongated tubular member to bend in a first direction, and a pulling force applied to the second end of the first steering cable causes the elongated tubular member to bend in a second direction opposite the first direction.

46. The catheter of claim 45, wherein the second steering cable comprises a first end and a second end, and wherein a pulling force applied to the first end of the second steering cable causes the elongated tubular member to bend in a third direction, and a pulling force applied to the second end of the second steering cable causes the elongated tubular member to bend in a fourth direction that is approximately opposite the third direction.

47. The catheter of claim 46, further comprising a steering device adjacent the proximal end of the elongated tubular member, the steering device being capable of manipulating the proximal ends of the steering cables thereby causing the distal end of the elongated tubular member to bend in four directions.