Ablation catheter electrode having multiple thermal sensors and method of use

• US 20080161797A1
• Filed: 12/29/2006
• Published: 07/03/2008
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Original Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Inventors: Dando, Jeremy D., Cao, Hong, Wang, Huisun
• Granted Patent: US 8,460,285 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/14 Probes or electrodes 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 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00577 Ablation
• 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: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

The invention relates to electrodes used in ablation catheter devices, where the electrodes contain two or more thermal sensors at different positions within the electrode that are capable of detecting temperature differences along the external surface of the electrode. In preferred embodiments, the thermal sensors are separated by one or more thermal insulating members and the thermal sensors are positioned near the external surface of the electrode at about the same distance from the end of the electrode, so that temperature measurements can indicate the position of the electrode with respect to the tissue desired to be ablated.

Claims

1. An electrode for an ablation catheter having a distal tip, a partially hollowed core region, and a proximal region, comprising:

at least two thermal sensors disposed in the partially hollowed core region of the electrode and near the external surface of the electrode; and

at least one thermal insulation member positioned to thermally shield one of the thermal sensors from one other thermal sensor,

wherein the electrode length is approximately the same as the electrode diameter or cross-sectional length, and

wherein each thermal sensor is positioned at approximately the same distance from the distal tip within the hollowed core region of the electrode.

2. The electrode of claim 1, wherein the catheter is an irrigated ablation catheter.

3. The electrode of claim 1, wherein the electrode has a cylindrical proximal region and a distal dome-shaped tip and is about 2.5 mm or less in length.

4. The electrode of claim 1, wherein the thermal sensors are thermocouple sensors.

5. The electrode of claim 1, wherein the thermal sensors are thermistor sensors.

6. The electrode of claim 1, wherein the thermal sensors are a combination of thermocouple and thermistor sensors.

7. The electrode of claim 1, wherein the thermal sensors are symmetrically distributed within the hollow core region.

8. The electrode of claim 1, wherein three or more thermal sensors are symmetrically distributed within the hollowed core region.

9. The electrode of claim 8, wherein three thermal insulation members separate three thermal sensors.

10. The electrode of claim 1, wherein four or more thermal sensors are symmetrically distributed within the hollowed core region.

11. The electrode of claim 10, wherein four thermal insulation members separate four thermal sensors.

12. The electrode of claim 1, wherein the electrode is made of Pt or a Pt/Ir alloy.

13. The electrode of claim 1, wherein at least one thermal sensor is positioned within the hollowed core region approximately 0.25 mm or less from the external surface of the electrode.

14. The electrode of claim 1, wherein the thermal insulation member comprises one or more polymer compositions.

15. The electrode of claim 14, wherein the one or more polymer compositions is selected from PEEK (polyetheretherketone), HDPE (high density polyethylene), Pebax (polyether block amides), nylon, polyimides, or polyurethane polymers.

16. A method of manufacturing an electrode, comprising

providing a cylindrical, metal or metal alloy electrode having a length approximately equal to its diameter,

cutting three or more slots or holes in the base of the electrode opposite a distal tip to create a partially hollowed core region,

filling or inserting a thermal insulation member into a slot or hole,

and inserting two or more thermal sensors into the slots or holes such that the thermal insulation member separates at least two thermal sensors.

17. The method of claim 16, wherein the electrode has a cylindrical proximal region and a distal dome-shaped distal tip and is about 2.5 mm or less in length.

18. The method of claim 16, wherein the thermal insulation member comprises one or more polymer compositions.

19. The method of claim 18, wherein the one or more polymer compositions is selected from PEEK (polyetheretherketone), HDPE (high density polyethylene), Pebax (polyether block amides), nylon, polyimides, or polyurethane polymers.

20. The method of claim 16, wherein at least one slot or hole for inserting a thermal sensor is cut to approximately 0.25 mm or less from the external surface of the electrode.

21. The method of claim 16, wherein the slots or holes are cut in a symmetrical pattern.

22. The method of claim 16, wherein slots cut for filling or inserting a thermal insulation member extend radially from the center of the electrode.

23. A method of using an ablation catheter electrode comprising:

providing, at the distal end of an ablation catheter, an electrode with at least two thermal sensors within the electrode body and positioned at approximately the same distance from the distal end of the electrode at different points near the electrode external surface,

wherein the at least two thermal sensors are separated from each other by a thermal insulation member,

inserting the catheter into a patient to cause the electrode to contact a target tissue,

measuring the temperatures of the thermal sensors during an ablation procedure, and

comparing the difference between temperature measurements on the thermal sensors to determine the orientation of the electrode in contact with the target tissue.