Targeted cooling of deployable microwave antenna

• US 8,292,880 B2
• Filed: 11/25/2008
• Issued: 10/23/2012
• Est. Priority Date: 11/27/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Vivant Medical, Inc. (Johnson Controls International plc)
• Inventors: Prakash, Mani N., Nguyen, Tao, Rusin, Christopher T.
• Primary Examiner(s): Dvorak, Linda
• Assistant Examiner(s): Antiskay, Brian M
• Application Number:
  US12/277,951
• Publication Number:
  US 20090138005A1
• Time in Patent Office: 1,428 Days
• Field of Search: 600/425, 600/433, 606/33, 606/41, 606/50, 607/101
• 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 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe

Abstract

The present disclosure relates to devices and methods for the treatment of tissue with microwave energy. The devices and methods disclosed herein utilize an antenna assembly which includes an elongate member, an outer conductor, an inner conductor, at least a portion of which is deployable, and a cooling system. The cooling system disclosed herein may significantly curtail any theoretical, or potential negative effects upon the target tissue experienced during the transmission of microwave energy to the antenna assembly due to ohmic heating.

Claims

1. A microwave tissue treatment device, comprising:

an antenna assembly including;

an elongate member defining a longitudinal axis and having proximal and distal ends;

an outer conductor and an inner conductor each disposed within the elongate member and extending along the longitudinal axis, wherein at least a portion of the inner conductor is configured to be deployable from the outer conductor such that the antenna assembly may transition from a first position to a second position;

a dielectric material disposed at least in part between the outer conductor and the inner conductor; and

a sleeve at least partially disposed about a distal portion of the inner conductor and defining at least one cavity, the at least one cavity having a proximal end and a distal end, wherein at least a portion of the sleeve is configured to be deployable from within a lumen defined by a distal portion of the outer conductor;

the dielectric material including a distal portion at least partially disposed within the lumen between the sleeve and the distal portion of the outer conductor; and

a cooling system including at least one inflow member and at least one outflow member, the at least one inflow member and the at least one outflow member disposed in fluid communication with the at least one cavity defined by the sleeve, the at least one inflow member and the at least one outflow member configured to circulate at least one fluid within the at least one cavity such that at least a portion of the inner conductor is in fluid contact with the at least one fluid.

2. The microwave tissue treatment device of claim 1, wherein the cavity includes at least two regions.

3. The microwave tissue treatment device of claim 1, wherein the cavity includes a proximal region, an intermediate region, and a distal region.

4. The microwave tissue treatment device of claim 3, wherein the at least one inflow member includes a first inflow member, a second inflow member, and a third inflow member, the at least one outflow member including a first outflow member, a second outflow member, and a third outflow member,

wherein the first inflow member and the first outflow member are in fluid communication with the proximal region, the second inflow member and the second outflow member being in fluid communication with the intermediate region, and the third inflow member and the third outflow member being in fluid communication with the distal region.

5. The microwave tissue treatment device of claim 2, further including at least one baffle member disposed within the cavity, the at least one baffle member defining the at least two regions.

6. The microwave tissue treatment device of claim 5, further including at least one temperature sensor, the at least one temperature sensor operatively connected to at least one of the at least two regions.

7. The microwave tissue treatment device of claim 5, wherein at least a portion of the inner conductor has a substantially tapered profile.

8. The microwave tissue treatment device of claim 4, further including a first baffle member and a second baffle member disposed within the cavity, the first baffle member and the proximal end of the cavity defining the proximal region, the first baffle member and the second baffle member defining the intermediate region, and the second baffle member and the distal end of the cavity defining the distal region, the first baffle member being configured to substantially prevent fluid communication between the proximal region and the intermediate region, the second baffle member being configured to substantially prevent fluid communication between the intermediate region and the distal region, the first baffle member and the proximal end of the cavity defining a first axial dimension therebetween, the first baffle member and the second baffle member defining a second axial dimension therebetween, the second baffle member and the distal end of the cavity defining a third axial dimension.

9. The microwave tissue treatment device of claim 8, wherein the first axial dimension is greater than the second axial dimension.

10. The microwave tissue treatment device of claim 8, wherein the proximal region defines a first internal diameter, the intermediate region defines a second internal diameter, and the distal region defines a third internal diameter.

11. The microwave tissue treatment device of claim 10, wherein the first internal diameter is greater than the second internal diameter and the second internal diameter is greater than the third internal diameter.

12. The microwave tissue treatment device of claim 10, wherein at least a portion of the inner conductor defines an arcuate profile when deployed.

13. The microwave tissue treatment device of claim 1, wherein at least a portion of the inner conductor defines a substantially non-arcuate profile when deployed.

14. The microwave tissue treatment device of claim 1, wherein the fluid is selected from the group consisting of water, saline, ammonium chloride, sodium nitrate, and potassium chloride.

15. The microwave tissue treatment device of claim 1, wherein the cooling system further includes at least one pump such that the at least one fluid may be circulated therethrough.

16. An improved microwave tissue treatment device having an antenna assembly that includes an outer conductor and an inner conductor with a dielectric material disposed at least in part therebetween, at least a portion of the inner conductor being deployable from the outer conductor, wherein the improvement comprises:

a sleeve at least partially disposed about a distal portion of the inner conductor and defining at least one cavity, wherein at least a portion of the sleeve is configured to be deployable from within a lumen defined by a distal portion of the outer conductor;

the dielectric material including a distal portion at least partially disposed within the lumen between the sleeve and the distal portion of the outer conductor;

at least one baffle member disposed within the sleeve and defining at least two regions thereof; and

a cooling system including at least one inflow member and at least one outflow member, the at least one inflow member and the at least one outflow member being in fluid communication with the at least one cavity.

17. A microwave tissue treatment device, comprising:

an antenna assembly including;

an elongate member defining a longitudinal axis and having proximal and distal ends;

an outer conductor and an inner conductor each disposed within the elongate member and extending along the longitudinal axis, the outer conductor including a distal portion, wherein at least a portion of the inner conductor is configured to be deployable from the distal portion of the outer conductor such that the antenna assembly may transition from a first position to a second position;

a dielectric material disposed at least in part between the outer conductor and the inner conductor; and

a sleeve at least partially disposed about a distal portion of the inner conductor and defining at least one cavity, the at least one cavity including a proximal region defining a first internal diameter, an intermediate region defining a second internal diameter, and a distal region defining a third internal diameter, wherein at least a portion of the sleeve is configured to be deployable from a lumen defined by the distal portion of the outer conductor;

the dielectric material including a distal portion at least partially disposed within the lumen between the sleeve and the distal portion of the outer conductor; and

a cooling system including at least one inflow member and at least one outflow member, the at least one inflow member and the at least one outflow member being in fluid communication with the at least one cavity defined by the sleeve, the at least one inflow member and the at least one outflow member configured to circulate at least one fluid within the at least one cavity such that at least a portion of the inner conductor is in fluid contact with the at least one fluid.

18. The microwave tissue treatment device of claim 17, wherein the third internal diameter is greater than the first internal diameter and the second internal diameter.