Devices and methods for cooling microwave antennas

• US 7,311,703 B2
• Filed: 07/18/2003
• Issued: 12/25/2007
• Est. Priority Date: 07/18/2003
• Status: Expired due to Fees

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Vivant Medical, Inc. (Johnson Controls International plc)
• Inventors: Turovskiy, Roman, Kim, Steven, Prakash, Mani, Rossetto, Francesca
• Primary Examiner(s): Peffley, Michael
• Assistant Examiner(s): VRETTAKOS, PETER J
• Application Number:
  US10/622,800
• Publication Number:
  US 20050015081A1
• Time in Patent Office: 1,621 Days
• Field of Search: 606 27- 52, 606 20- 26
• US Class Current: 606/33
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2018/00017 with gas
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/0022 Balloons
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00744 Fluid flow
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00863 Fluid flow
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/1838 Dipole antennas
• CPC Class Codes: A61N 5/045 specially adapted for treatment inside the body

Abstract

Devices and methods for cooling microwave antennas are disclosed herein. The cooling systems can be used with various types of microwave antennas. One variation generally comprises a handle portion with an elongate outer jacket extending from the handle portion. A microwave antenna is positioned within the handle and outer jacket such that cooling fluid pumped into the handle comes into contact directly along a portion of the length, or a majority of the length, or the entire length of the antenna to allow for direct convective cooling. Other variations include cooling sheaths which form defined cooling channels around a portion of the antenna. Yet another variation includes passively-cooled systems which utilize expandable balloons to urge tissue away from the surface of the microwave antenna as well as cooling sheaths which are cooled through endothermic chemical reactions. Furthermore, the microwave antennas themselves can have cooling lumens integrated directly therethrough.

Claims

1. A cooling system for use with a microwave antenna, comprising:

a cooling jacket adapted to at least partially surround a microwave antenna and defining a fluid channel around at least a portion of the microwave antenna, the cooling jacket further defining at least a first and a second region longitudinally adjacent to and separate from one another, the first region adapted to retain cooling fluid from at least one source that is in fluid contact with a first portion of the microwave antenna, and the second region adapted to retain cooling fluid from at least one source that is in fluid contact with a second portion of the microwave antenna; and

wherein the cooling jacket is further adapted to circulate a cooling fluid through the fluid channel such that at least a portion of the microwave antenna is in direct fluid contact with the cooling fluid and wherein the microwave antenna comprises a distal tip configured to be advanced percutaneously through tissue.

2. The system of claim 1 further comprising at least one inlet lumen and at least one outlet lumen each in fluid communication with the cooling jacket for circulating the cooling fluid therethrough.

3. The system of claim 2 wherein a distal end of the inlet lumen is positioned near or at a distal end of the microwave antenna.

4. The system of claim 2 wherein a distal end of the outlet lumen is positioned proximally of the microwave antenna distal end.

5. The system of claim 2 wherein the inlet lumen is defined along an outer surface of the cooling jacket.

6. The system of claim 2 wherein the inlet lumen is defined within a wall of the cooling jacket.

7. The system of claim 1 further comprising a tip at a distal end of the cooling jacket.

8. The system of claim 7 wherein the tip is tapered.

9. The system of claim 7 further comprising a power generator in electrical communication with the tip.

10. The system of claim 7 wherein a distal end of the microwave antenna is securable to a proximal portion of the tip.

11. The system of claim 10 wherein the tip is adapted to be in electrical communication with the distal end of the microwave antenna.

12. The system of claim 1 further comprising a handle assembly for attachment to a proximal end of the cooling jacket.

13. The system of claim 12 wherein the handle assembly defines at least one lumen therethrough which is in fluid communication with the cooling jacket.

14. The system of claim 1 further comprising a pump for circulating the cooling fluid through the cooling jacket.

15. The system of claim 1 wherein the cooling fluid comprises a liquid, gas, or combination thereof.

16. The system of claim 15 wherein the liquid comprises water or saline.

17. The system of claim 15 wherein the gas is selected from the group consisting of nitrous oxide, nitrogen, and carbon dioxide.

18. The system of claim 1 further comprising a temperature sensor for sensing a temperature of the system.

19. The system of claim 1 further comprising an introducer which is insertable into the cooling jacket.

20. The system of claim 1 wherein the cooling jacket is configured in length to match a radiating portion of the microwave antenna.

21. The system of claim 1 wherein the first region is adapted to retain the cooling fluid from a first source in fluid contact with a first portion of the microwave antenna, and the second region is adapted to retain cooling fluid from a second source in fluid contact with a second portion of the microwave antenna.

22. The system of claim 21 wherein the cooling fluid from the first source is maintained at a first temperature and the cooling fluid from the second source is maintained at a second temperature.

23. The system of claim 21 wherein the cooling jacket defines a plurality of additional regions adjacent to and separate from one another.

24. The system of claim 1 wherein the first region is adapted to retain the cooling fluid from a first source in fluid contact with a first portion of the microwave antenna, and the second region is adapted to retain cooling fluid from the first source in fluid contact with a second portion of the microwave antenna.