Methods and devices for creating electrical block at specific sites in cardiac tissue with targeted tissue ablation

• US 20050090820A1
• Filed: 10/22/2004
• Published: 04/28/2005
• Est. Priority Date: 10/24/2003
• Status: Active Grant

• Current Assignee: Syntach AG
• Original Assignee: Sinus Rhythm Technologies, Inc.
• Inventors: Cornelius, Richard, Swanson, William
• Granted Patent: US 7,266,414 B2
• 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 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00898 Alarms or notifications created in response to an abnormal condition

Abstract

In one embodiment, the present invention provides a bipolar ablation device with multiple needle electrodes that penetrate a desired target tissue. These electrodes may be arranged in a variety of therapeutically effective arrangements, such as a comb-like shape, a multi-needle wheel, or an expanding bow design. By contacting and preferably penetrating the cardiac tissue with bipolar electrodes, a user can more precisely create ablation-induced scarring and thus electrical block at desired target locations without causing unwanted damage and related complications.

Claims

1. An ablation device comprising:

a body having a proximal and distal end;

a first set and a second set of electrically conductive tissue penetrating elements disposed at said distal end of said body;

said first set of electrically conductive tissue penetrating elements having a positive polarity and said second set of electrically conductive tissue penetrating elements having a negative polarity;

said first set positioned opposite said second set; and

,

an ablative energy source connected to second set of electrically conductive tissue penetrating elements.

2. The ablation device of claim 1, wherein each of said electrically conductive tissue penetrating elements has a triangular shape.

3. The ablation device of claim 1, wherein each of said electrically conductive tissue penetrating elements has a slender body terminating in an angled tip.

4. The ablation device of claim 1, wherein each of said electrically conductive tissue penetrating elements has a pointed needle shape.

5. The ablation device of claim 1, wherein each of said electrically conductive tissue penetrating elements includes a nonconductive coating disposed over a portion of said element.

6. The ablation device of claim 1, wherein said first set and said second set of electrically conductive tissue penetrating elements includes a linear array of electrically conductive tissue penetrating elements.

7. The ablation device of claim 1, wherein said first and second set are comprised of a first wheel and second wheel, respectively, of electrically conductive tissue penetrating elements.

8. The ablation device of claim 7, wherein an axis of said first wheel and an axis of said second wheel are at an angle relative to each other.

9. The ablation device of claim 8, wherein said angle forms a “

V”

shape between said first and second wheel.

10. The ablation device of claim 1, wherein said body is a hand tool.

11. The ablation device of claim 1, wherein said body is a catheter assembly.

12. A method of ablating tissue comprising:

identifying tissue of a desired ablation site;

introducing a first set of ablation elements of a predetermined polarity to said ablation site;

introducing a second set of ablation elements of an opposite polarity to a position spaced from said first set of ablation elements at said ablation site; and

,

energizing said ablation elements so as to ablate said tissue in the region between said first and second sets of ablation elements.

13. A method according to claim 12, wherein energizing said ablation elements includes energizing said ablation elements so as to form an electrical conduction block at said ablation site.

14. A method according to claim 12, wherein the introducing of said first and second sets of ablation elements includes introducing a first linear array of tissue penetrating elements and a second linear array of tissue penetrating elements, respectively.

15. A method according to claim 12, wherein the introducing of said first and second sets of ablation elements includes introducing a first circular element of tissue penetrating elements and a second circular element of tissue penetrating elements.

16. A method according to claim 15, wherein the introducing includes inclining said first circular element relative to said second circular element.

17. A method according to claim 12, wherein the introducing of said first and second sets of ablation elements includes introducing ablation elements that are partially electrically insulated.

18. A device for creating electrical block in heart tissue comprising:

a device body;

a plurality of pliable bow electrodes extending along and around said device body;

an electrically conductive tissue penetrating element disposed on each of said bow electrodes;

said pliable bow electrodes being movable along an axis of said device body between an expanded and a retracted position;

said expanded position positioning each of said tissue penetrating elements circumferentially outwardly relative to said device body;

said retracted position positioning each of said tissue penetrating elements generally along a surface of said body; and

an electrical energy source connected to said bow electrodes.

19. The device of claim 18, wherein said electrical energy source is an RF energy source.

20. The device of claim 18, wherein each electrically conductive tissue penetrating element is of alternating polarity.

21. The device of claim 18, wherein said device body is a catheter.

22. An ablation device comprising:

a first tissue penetrating element and a second tissue penetrating element;

an ablation electrode disposed on each of said first and second tissue penetrating elements;

a ring electrode disposed on each of said first and second tissue penetrating elements;

an impedence measuring mechanism for measuring impedance between said ring electrode and said ablation electrode; and

,

an ablative energy source connected to ablation electrode.

23. An ablation device according to claim 22, further comprising a catheter for removably housing said first and second tissue penetrating elements.

24. An ablation device according to claim 22, further comprising a non-conductive region disposed between said ablation electrode and said ring electrode.

25. An ablation device according to claim 22, wherein said first tissue penetrating element and said second tissue penetrating element are each disposed on a first and second array of tissue penetrating elements, respectively.

26. An ablation device according to claim 25, wherein said first and second arrays are linear arrays.

27. An ablation device according to claim 25, wherein said first and second arrays are circular arrays.

28. A method of ablating tissue comprising:

providing at least one tissue penetrating element having an ablation electrode and a ring electrode;

introducing said tissue penetrating element into a tissue region;

measuring impedance between said ablation electrode and said ring electrode;

determining the nature of said tissue region according to said impedance measurement;

ablating said tissue region when said impedance measurement corresponds to said desired nature of said tissue region.

29. The method according to claim 28, wherein the providing of at least one tissue penetrating element includes providing at least two tissue penetrating elements.

30. The method according to claim 29, wherein ablating said tissue region includes applying bi-polar ablation energy to said tissue region.

32. The method according to claim 28, wherein introducing said tissue penetrating element includes introducing said tissue penetrating element into a tissue region believed to cause atrial fibrillation.

33. The method according to claim 32, wherein introducing said tissue penetrating element includes introducing said tissue penetrating element into a fat pad of an endocardial surface of the heart.

34. The method according to claim 28, wherein determining the nature of said tissue region includes obtaining an impedance measurement that corresponds to fat tissue.

35. The method according to claim 34, wherein the ablating said tissue region includes ablating a region of fat tissue.