PRE-FORMED CURVED ABLATION CATHETER

• US 20110144633A1
• Filed: 12/11/2009
• Published: 06/16/2011
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Original Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Inventors: Govari, Assaf
• Granted Patent: US 9,861,438 B2
• Time in Patent Office: Days
• US Class Current: 606/33
• 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 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/067 for measuring angles
• CPC Class Codes: C08L 2201/12 Shape memory

Abstract

A medical device includes an insertion tube, having a longitudinal axis and having a distal end adapted for insertion through a body passage into a cavity within a body of a patient. An electrode is located on the distal end of the insertion tube and is configured to contact tissue in the cavity. A resilient member is contained within the distal end of the insertion tube and is configured, when unconstrained, to cause the distal end to bend away from the longitudinal axis in a curved shape and to straighten toward the longitudinal axis when subjected to a force.

Claims

1. A medical device, comprising:

an insertion tube, having a longitudinal axis and having a distal end adapted for insertion through a body passage into a cavity within a body of a patient;

an electrode, which is located on the distal end of the insertion tube and is configured to contact tissue in the cavity; and

a resilient member, which is contained within the distal end of the insertion tube and is configured, when unconstrained, to cause the distal end to bend away from the longitudinal axis in a curved shape and to straighten toward the longitudinal axis when subjected to a force.

2. The device according to claim 1, wherein the resilient member comprises a shape memory material.

3. The device according to claim 1, and comprising at least one position transducer in the distal end of the insertion tube.

4. The device according to claim 3, wherein the at least one position transducer is configured to measure a bend angle of the distal end of the insertion tube.

5. The device according to claim 4, wherein the at least one position transducer comprises two position transducers at different longitudinal locations within the distal end of the insertion tube.

6. The device according to claim 1, wherein the resilient member is configured to straighten toward the longitudinal axis when the force is applied in an inward radial force.

7. The device according to claim 6, wherein the resilient member is configured to buckle when the radial force exceeds a predetermined threshold.

8. Medical apparatus, comprising:

a sheath, which has a longitudinal axis and a distal opening and is adapted for insertion through a body passage into a cavity within a body of a patient; and

a catheter, which is configured for insertion through the sheath into the cavity and which has a resilient distal end that is formed so that, when unconstrained, the distal end bends away from the longitudinal axis in a curved shape, and when subjected to a force, the distal end straightens toward the longitudinal axis.

9. The apparatus according to claim 8, wherein the sheath exerts the force in an inward radial direction so as to straighten the distal end of the catheter during passage of the distal end through the sheath, and wherein the distal end of the catheter assumes the curved shape after passing through the distal opening of the sheath into the cavity.

10. The apparatus according to claim 9, wherein the catheter is configured to rotate about the axis within the sheath.

11. The apparatus according to claim 8, wherein the catheter comprises an electrode at the distal end, which is configured to contact tissue in the cavity.

12. The apparatus according to claim 11, and comprising a radio frequency (RF) generator, which is coupled to supply RF energy through the catheter to the electrode so as to ablate the tissue.

13. The apparatus according to claim 8, wherein the catheter comprises a position transducer in the distal end, and wherein the apparatus comprises a position sensing system, which is configured to communicate with the position transducer so as to determine a location of the distal end within the body.

14. The apparatus according to claim 13, wherein the position sensing system is configured to provide an indication of a bend angle of the distal end of the catheter.

15. A method for medical treatment, comprising:

inserting a sheath, having a longitudinal axis and a distal opening, through a body passage into a cavity within a body of a patient;

inserting into the sheath a catheter having a resilient distal end that is formed so that, when unconstrained, the distal end bends away from the longitudinal axis in a curved shape, and when subjected to a force, the distal end straightens toward the longitudinal axis;

advancing the catheter through the sheath so that the distal end of the catheter passes through the distal opening of the sheath into the cavity and assumes the curved shape;

manipulating the catheter within the cavity so that the distal end contacts tissue in the cavity; and

moving the catheter within the sheath while the distal end contacts the tissue so as to cause the distal end to trace a desired path along the tissue.

16. The method according to claim 15, wherein moving the catheter comprises rotating the catheter about the axis.

17. The method according to claim 16, wherein the cavity comprises a blood vessel, and wherein rotating the catheter causes the distal end to trace a circular path around an internal circumference of the blood vessel.

18. The method according to claim 17, wherein inserting the sheath comprises passing the sheath percutaneously through a vascular system of the patient into a left atrium of a heart of the patient, and wherein advancing the catheter comprises positioning the distal end of the catheter in a pulmonary vein so as to trace the circular path within an ostium of the pulmonary vein.

19. The method according to claim 15, and comprising applying energy through the catheter so as to ablate the tissue along the path.

20. The method according to claim 19, wherein the catheter comprises an electrode at the distal end, and wherein applying the energy comprises supplying radio-frequency (RF) electrical energy to the electrode.

21. The method according to claim 15, and comprising providing an indication of a bending angle of the distal end of the catheter, and controlling a pressure of the distal end against the tissue responsively to the indication.