DEVICES AND METHODS FOR COOLING MICROWAVE ANTENNAS
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.
1 . (canceled)
2 . A microwave antenna assembly comprising:
a feedline including a first conductor;
a radiating portion extending from a distal end of the feedline; and
a cooling system including:
an external tubular member extending along a portion of a length of the first conductor and defining a first channel for delivering fluid; and
an outer tubular member coaxially aligned with the first conductor, the outer tubular member defining a second channel in fluid communication with the first channel such that fluid is exchangeable therebetween, the first conductor being disposed within the second channel, and a longitudinal axis defined by the outer tubular member being laterally offset from a longitudinal axis defined by the external tubular member.
3 . The microwave antenna assembly of claim 2 , wherein the external tubular member is externally located from the outer tubular member.
4 . The microwave antenna assembly of claim 2 , wherein the external tubular member is non-electrically conductive.
5 . The microwave antenna assembly of claim 2 , wherein the external tubular member is a separate tubular member attached to a surface of the outer tubular member.
6 . The microwave antenna assembly of claim 2 , wherein the feedline further includes a second conductor and a dielectric material, the dielectric material surrounds a portion of the second conductor, and the first conductor surrounds a portion of the dielectric material.
7 . The microwave antenna assembly of claim 2 , wherein the outer tubular member further includes a tapered distal end terminating in a tip.
8 . The microwave antenna assembly of claim 2 , wherein a distal end of the radiating portion extends beyond a distal end of the external tubular member.
9 . The microwave antenna assembly of claim 2 , further comprising a fluid source, wherein the external tubular member and the outer tubular member each define a conduit in fluid communication with the fluid source to provide fluid to the first and second channels.
10 . The microwave antenna assembly of claim 9 , wherein the fluid is communicated between the first and second channel via an opening.
11 . The microwave antenna assembly of claim 10 , wherein a location of the opening is determined based on a desired cooling effect of the radiating portion.
12 . The microwave antenna assembly of claim 9 , wherein the fluid source is configured to generate one of a positive pressure or a negative pressure within at least one of the first or second channels.
13 . The microwave antenna assembly of claim 2 , wherein the radiating portion defines a curved profile and an ablation region therein.
14 . The microwave antenna assembly of claim 2 , wherein the radiating portion defines a straight probe profile.
15 . The microwave antenna assembly of claim 2 , wherein the cooling system further includes a temperature sensor configured to sense a temperature of at least one of the first conductor or the radiating portion.
16 . The microwave antenna assembly of claim 2 , wherein the second channel is defined between the outer tubular member and the first conductor.