LOW POWER TISSUE ABLATION SYSTEM

• US 20150005767A1
• Filed: 09/11/2014
• Published: 01/01/2015
• Est. Priority Date: 07/11/2005
• Status: Active Grant

• Current Assignee: Medtronic Ablation Frontiers LLC (Medtronic Plc)
• Original Assignee: Medtronic Ablation Frontiers LLC (Medtronic Plc)
• Inventors: Werneth, Randell L., Kunis, Christopher G., Flaherty, J. Christopher, Sherman, Marshall L.
• Granted Patent: US 9,566,113 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• 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 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00898 Alarms or notifications created in response to an abnormal condition
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing

Abstract

Devices, systems and methods are disclosed for the ablation of tissue. Embodiments include an ablation catheter that has an array of ablation elements attached to a deployable carrier assembly. The carrier assembly can be constrained within the lumen of a catheter, and deployed to take on an expanded condition. The carrier assembly includes multiple electrodes that are configured to ablate tissue at low power. Additional embodiments include a system that includes an interface unit for delivering one or more forms of energy to the ablation catheter.

Claims

1. A medical device for tissue ablation, the device comprising:

an elongate body including a distal portion and a proximal portion; and

a treatment array at the distal portion, the treatment array including at least one ablation element defining a surface area, the at least one ablation element including an energy delivery portion for delivering energy to tissue and a heat dissipation portion for dissipating heat away from the at least one ablation element, the second portion making up a greater amount of the surface area of the at least one ablation element than the first portion.

2. The medical device of claim 1, wherein the heat dissipation portion makes up at least 60% of the surface area of the at least one ablation element.

3. The medical device of claim 1, wherein the heat dissipation portion makes up at least 75% of the surface area of the at least one ablation element.

4. The medical device of claim 1, wherein the treatment array further includes a plurality of carrier arms.

5. The medical device of claim 4, wherein at least one ablation element is coupled to each carrier arm.

6. The medical device of claim 1, wherein the at least one ablation element has a triangular cross-sectional shape and includes a first surface, a second surface, and a third surface.

7. The medical device of claim 6, wherein the first surface is the energy delivery portion.

8. The medical device of claim 7, wherein the second surface and the third surface together are the heat dissipation portion.

9. The medical device of claim 8, wherein the second surface and the third surface are not in contact with each other.

10. The medical device of claim 9, wherein the second surface and the third surface define a channel that is open to the environment.

11. The medical device of claim 10, wherein the channel is configured to allow an environmental fluid to enter the channel.

12. The medical device of claim 6, wherein the first surface includes the heat dissipation portion.

13. The medical device of claim 12, wherein each of the second surface and the third surface includes at least a portion of the energy delivery portion and at least a portion of the heat dissipation portion.

14. The medical device of claim 1, wherein the heat dissipation portion is at least one of electrically nonconductive, minimally electrically conductive, and electrically isolated from the energy delivery portion.

15. The medical device of claim 1, wherein the heat dissipation portion includes one or more fins extending away from the energy delivery portion.

16. The medical device of claim 1, wherein the at least one ablation element has a semi-circular cross-sectional shape and includes a substantially planar first surface and an arcuate second surface.

17. The medical device of claim 16, wherein the first surface includes a first portion of the heat dissipation portion and the second surface includes the energy delivery portion and a second portion of the heat dissipation portion.

18. An ablation system for treating a patient, the system comprising:

an elongate body including a distal portion and a proximal portion;

a treatment array at the distal portion, the treatment array including at least one ablation element defining a surface area, the at least one ablation element including an energy delivery portion for delivering energy to tissue and a heat dissipation portion for dissipating heat away from the at least one ablation element, the second portion making up a greater amount of the surface area of the at least one ablation element than the first portion; and

an interface unit for providing energy to the ablation catheter,

the at least one ablation element being configured to rapidly transition from a first temperature at which tissue ablation occurs to a second temperature that is approximately body temperature.

19. The system of claim 18, wherein the heat dissipation portion makes up at least 75% of the surface area of the at least one ablation element and is in contact with the patient'"'"'s circulating blood when the energy is delivered.

20. The system of claim 18, wherein the heat dissipation portion makes up at least 85% of the surface area of the at least one ablation element and is in contact with the patient'"'"'s circulating blood when the energy is delivered.