Methods and apparatus for assessing and improving electrode contact with cardiac tissue

• US 20100198040A1
• Filed: 06/28/2007
• Published: 08/05/2010
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Friedman, Paul, Johnson, Jeremiah, Amara, Ryan, Bruce, Charles J., Kozel, Peter D.
• Granted Patent: US 8,504,132 B2
• Time in Patent Office: Days
• US Class Current: 600/374
• CPC Class Codes: A61B 18/1206 Generators therefor
• 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 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00797 measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00815 measured by a thermistor
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2218/002 Irrigation
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation

Abstract

Embodiments of the invention relate to methods for assessing and/or improving contact between an electrophysiology catheter and tissue, and catheters for performing the methods. One embodiment relates to a catheter comprising a braided conductive member coupled to the distal end of a shaft, wherein the braided conductive member comprises a plurality of pressure sensitive wires. Another embodiment relates to a catheter comprising a braided conductive member having a plurality of sectors and coupled to the distal end of a shaft, and a balloon assembly constructed and arranged to selectively apply distal pressure to one or more sectors of the braided conductive member.

Claims

1. A method, comprising:

introducing a catheter having a braided conductive member into a heart;

positioning the braided conductive member at a desired location for performing ablation or mapping;

sensing a first degree of pressure between a first sector of the braided conductive member and first adjacent tissue;

sensing a second degree of pressure between a second sector of the braided conductive member and second adjacent tissue; and

providing an indication of contact between at least one sector of the braided conductive member and adjacent tissue based on at least one of the first degree of pressure and the second degree of pressure.

2. The method of claim 1, further comprising:

determining whether the first degree of pressure exceeds a predetermined threshold; and

determining whether the second degree of pressure exceeds the predetermined threshold;

wherein providing the indication comprises providing an indication that the first degree of pressure and/or the second degree of pressure has exceeded the predetermined threshold.

3. The method of claim 2, wherein the predetermined threshold is selected based on a degree of pressure required for successful lesion formation.

4. The method of claim 1, wherein providing the indication comprises providing an indication that each of the first degree of pressure and the second degree of pressure has exceeded a predetermined threshold.

5. The method of claim 1, wherein positioning the braided conductive member comprises positioning the braided conductive member at an orifice of the heart.

6. The method of claim 1, further comprising:

using the braided conductive member, forming a lesion in the first adjacent tissue in response to an indication that the first degree of pressure is acceptable for successful lesion formation.

7. The method of claim 6, wherein the step of forming the lesion comprises forming the lesion automatically in response to the indication that the first degree of pressure is acceptable for successful lesion formation.

8. The method of claim 1, wherein the braided conductive member comprises a plurality of pressure sensitive wires, and wherein sensing the first degree of pressure comprises sensing a pressure on at least one of the plurality of pressure sensitive wires.

9. The method of claim 8, further comprising:

detecting a mapping signal from the heart using at least one of the pressure sensitive wires.

10. The method of claim 8, further comprising:

applying ablation energy to the heart using at least one of the pressure sensitive wires.

11. The method of claim 1, further comprising:

adjusting a degree of contact between at least a portion of the braided conductive member and adjacent tissue in response to the indication.

12. The method of claim 11, wherein adjusting the degree of contact comprises adjusting the inflation of a balloon disposed within the braided conductive member.

13. The method of claim 12, wherein the first and second sectors are electrically independent, and wherein the balloon has dimensions corresponding to dimensions of the first electrically independent sector.

14. The method of claim 11, wherein adjusting the degree of contact comprises independently adjusting the inflation of a plurality of balloons disposed within the braided conductive member.

15. The method of claim 1, further comprising:

increasing the degree of contact between the first sector and the first adjacent tissue in response to an indication that the first pressure is below a predetermined threshold.

16. The method of claim 1, further comprising:

using the braided conductive member, applying ablation energy to the first adjacent tissue; and

using the braided conductive member, measuring a signal level from the first adjacent tissue; and

determining if the signal level is below a first predetermined threshold;

determining if first degree of pressure exceeds a second predetermined threshold; and

if the signal level is below the first predetermined threshold and the first degree of pressure exceeds the second predetermined threshold, providing an indication of successful lesion formation in the first adjacent tissue.

17. The method of claim 16, wherein providing an indication of successful lesion formation in the first adjacent tissue comprises providing the indication on the catheter

18. The method of claim 16, wherein providing an indication of successful lesion formation in the first adjacent tissue comprises providing the indication on a controller coupled to the catheter.

19. The method of claim 1, further comprising:

determining if the first degree of pressure is below a predetermined threshold; and

prohibiting application of ablation energy to the first sector if the first degree of pressure is below the predetermined threshold.

20. An electrophysiology catheter comprising:

a handle;

a shaft coupled to a distal end of the handle; and

a braided conductive member coupled to a distal end of the shaft;

wherein the braided conductive member comprises a plurality of pressure sensitive wires.

21. The electrophysiology catheter of claim 20, wherein the plurality of pressure sensitive wires are disposed at least partially in a distally facing surface of the braided conductive member.

22. The electrophysiology catheter of claim 20, wherein the plurality of pressure sensitive wires are woven into the braided conductive member.

23. The electrophysiology catheter of claim 20, wherein the impedance of the plurality of pressure sensitive wires varies in response to the pressure applied to the wires.

24. The electrophysiology catheter of claim 20, wherein the braided conductive member comprises a plurality of equally-sized sectors, and wherein each of the sectors comprises a pressure sensitive wire.

25. The electrophysiology catheter of claim 24, wherein each of the sectors is electrically independent.

26. The electrophysiology catheter of claim 20, further comprising an indicator coupled to one or more of the pressure sensitive wires, and wherein the indicator is adapted to indicate whether the degree of pressure on one or more of the plurality of sectors has exceeded a predetermined threshold.

27. The electrophysiology catheter of claim 26, wherein the indicator comprises a light emitting diode (LED).

28. The electrophysiology catheter of claim 20, further comprising a balloon assembly constructed and arranged to selectively apply distal pressure to one or more sectors of the braided conductive member.

29. The electrophysiology catheter of claim 28, wherein the balloon assembly is disposed in an interior space formed by the braided conductive member.

30. The electrophysiology catheter of claim 28, wherein the catheter is adapted to automatically adjust an inflation of all or a portion of the balloon assembly in response to an indication of pressure received from one or more of the plurality of pressure sensitive wires.

31. A system, comprising:

the catheter of claim 20; and

a controller coupled thereto.

32. The system of claim 31, wherein the controller is adapted to indicate whether the degree of pressure on one or more of the plurality of sectors has exceeded a predetermined threshold.

33. The system of claim 31, wherein:

the controller comprises an ablation energy generator; and

the controller is adapted to determine if the pressure detected by at least one of the plurality of pressure sensitive wires is below a predetermined threshold and prohibit the application of ablation energy to at least a portion of the braided conductive member if the pressure is below the predetermined threshold.

34. The system of claim 31, wherein:

the controller comprises an ablation energy generator; and

the controller is adapted to determine if the pressure detected by at least one of the plurality of pressure sensitive wires is above a predetermined threshold and automatically apply ablation energy to at least a portion of the braided conductive member if the pressure is above the predetermined threshold.

35. The system of claim 31, wherein:

the catheter further comprises a balloon assembly constructed and arranged to selectively apply distal pressure to one or more sectors of the braided conductive member;

wherein the controller further comprises an inflation mechanism adapted to automatically adjust an inflation of the balloon assembly in response to at least one signal received from the plurality of pressure sensitive wires.

36. The system of claim 31, wherein:

the controller comprises an ablation energy generator; and

the controller is adapted to apply ablation energy to the pressure sensitive wires.

37. The system of claim 31, wherein:

the controller comprises a recording device; and

controller is adapted to transmit mapping signals from the pressure sensitive wires to the recording device.

38. An electrophysiology catheter comprising:

a handle;

a shaft coupled to a distal end of the handle;

a braided conductive member coupled to a distal end of the shaft, the braided conductive member comprising a plurality of sectors; and

a balloon assembly constructed and arranged to selectively apply distal pressure to one or more sectors of the braided conductive member.

39. The electrophysiology catheter of claim 38, wherein the balloon assembly is disposed in an interior space formed by the braided conductive member.

40. The electrophysiology catheter of claim 38, wherein the braided conductive member comprises first and second electrically independent sectors respectively comprising the first and second locations, and wherein the balloon assembly comprises first and second independently inflatable balloons having dimensions respectively corresponding to the first and second electrically independent sectors.

41. An electrophysiology catheter comprising:

a handle;

a shaft coupled to a distal end of the handle;

a braided conductive member coupled to a distal end of the shaft, the braided conductive member comprising a plurality of sectors; and

means, coupled to the shaft, for selectively applying distal pressure to one or more sectors of the braided conductive member.