Fluid cooled choke dielectric and coaxial cable dielectric

Abstract

The microwave antenna assembly includes a feedline electrically connected to an elongated shaft by a choke electrical connector. The feedline includes an inner conductor, an outer conductor, an elongated shaft and a choke electrical connector. The inner conductor is disposed in coaxial arrangement with the inner conductor and forms a dielectric supply lumen therebetween. The elongated shaft at least partially surrounding the feedline and form a dielectric return lumen therebetween. The choke electrical connector surrounds at least a portion of the feedline and electrically connects the feedline outer conductor to the elongated shaft. A low-loss dielectric fluid is supplied between the inner conductor and the outer conductor of the feedline and forms a dielectric barrier therebetween. The low-loss dielectric fluid also forms a dielectric barrier between the outer conductor of the feedline and the elongated shaft and the choke electrical connector forms a plurality of apertures extending therethrough, the apertures forming at least a portion of the dielectric return lumen.

1 - 17 . (canceled) 
     
     
         18 . A microwave ablation system, comprising:
 a power generating source configured to supply microwave energy to a microwave antenna assembly, the microwave antenna assembly including:
 a feedline having a length, the feedline including:
 an inner conductor; 
 an outer conductor in a coaxial arrangement with the inner conductor, the inner conductor and outer conductor forming a supply lumen therebetween; 
 
 an elongated shaft at least partially surrounding the feedline, the elongated shaft and the feedline forming a return lumen therebetween in fluid communication with the supply lumen; and 
 a choke including a substantially cylindrical inner surface surrounding at least a portion of the length of the feedline and configured to electrically connect the outer conductor to the elongated shaft; and 
   a fluid supply configured to supply a low-loss dielectric fluid to the supply lumen, wherein a first dielectric barrier is formed between the inner conductor and the outer conductor, and to receive the low-loss dielectric fluid from the return lumen, wherein a second dielectric barrier is formed between the outer conductor and the elongated shaft.   
     
     
         19 . The system of  claim 18 , wherein the fluid supply includes a fluid analyzer configured to determine at least one characteristic of the low-loss dielectric fluid. 
     
     
         20 . The system of  claim 19 , wherein the fluid analyzer is configured to determine a strength of at least one of the first dielectric barrier or the second dielectric barrier based on the at least one characteristic of the low-loss dielectric fluid. 
     
     
         21 . The system of  claim 19 , wherein the at least one characteristic of the low-loss dielectric fluid is selected from the group consisting of impedance and temperature. 
     
     
         22 . The system of  claim 18 , wherein the microwave antenna assembly includes a radiating section connected to a distal end of the feedline, the radiating section configured to radiate microwave energy supplied from the power generating source. 
     
     
         23 . The system of  claim 19 , wherein the power generating source is configured to adjust energy delivered to the radiating section based on the at least one characteristic of the low-loss dielectric fluid. 
     
     
         24 . The system of  claim 18 , wherein the fluid supply includes a fluid cooler configured to remove thermal energy from the low-loss dielectric fluid received from the return lumen. 
     
     
         25 . The system of  claim 18 , wherein the low-loss dielectric fluid is configured to absorb thermal energy from at least one of the inner conductor or the outer conductor. 
     
     
         26 . The system of  claim 18 , wherein the choke includes a plurality of apertures disposed therethrough, the plurality of apertures forming at least a portion of the return lumen. 
     
     
         27 . A microwave ablation system, comprising:
 a power generating source configured to supply microwave energy to a microwave antenna assembly, the microwave antenna assembly including:
 a feedline having a length, the feedline including:
 an inner conductor; and 
 an outer conductor in a coaxial arrangement with the inner conductor, the inner conductor and outer conductor forming a supply lumen therebetween; 
 
 an elongated shaft at least partially surrounding the feedline, the elongated shaft and the feedline forming a return lumen therebetween in fluid communication with the supply lumen; 
 a choke including a substantially cylindrical inner surface surrounding at least a portion of the length of the feedline and configured to electrically connect the outer conductor to the elongated shaft; and 
 a radiating section connected to a distal end of the feedline and configured to radiate microwave energy supplied from the power generating source; and 
   a fluid supply including a fluid analyzer, the fluid supply configured to supply a low-loss dielectric fluid to the supply lumen and to receive the low-loss dielectric fluid from the return lumen, wherein a first dielectric barrier is formed between the inner conductor and the outer conductor and a second dielectric barrier is formed between the outer conductor and the elongated shaft, the fluid analyzer configured to determine a strength of at least one of the first dielectric barrier or the second dielectric barrier based on at least one characteristic of the low-loss dielectric fluid received from the return lumen.   
     
     
         28 . The system of  claim 27 , wherein the at least one characteristic of the low-loss dielectric fluid is selected from the group consisting of impedance and temperature. 
     
     
         29 . The system of  claim 27 , wherein the power generating source is configured to adjust energy supplied to the radiating section based on the at least one characteristic of the low-loss dielectric fluid. 
     
     
         30 . The system of  claim 27 , wherein the fluid supply includes a fluid cooler configured to remove thermal energy from the low-loss dielectric fluid. 
     
     
         31 . A microwave antenna assembly, comprising:
 a feedline having a length, the feedline including:
 an inner conductor; and 
 an outer conductor in a coaxial arrangement with the inner conductor, the inner conductor and outer conductor forming a supply lumen therebetween; 
   an elongated shaft, at least partially surrounding the feedline, the elongated shaft and the feedline forming a return lumen therebetween in fluid communication with the supply lumen, wherein the supply lumen is configured to receive a low-loss dielectric fluid from a fluid supply such that a first dielectric barrier is formed between the inner conductor and the outer conductor, and the return lumen is configured to return the low-loss dielectric fluid to a fluid supply such that a second dielectric barrier is formed between the outer conductor and the elongated shaft; and   a choke including a substantially cylindrical inner surface surrounding at least a portion of the length of the feedline and configured to electrically connect the outer conductor to the elongated shaft.   
     
     
         32 . The assembly of  claim 31 , further comprising:
 a radiating section connected to the distal end of the feedline and configured to radiate microwave energy supplied from a power generating source.   
     
     
         33 . The assembly of  claim 31 , wherein the low-loss dielectric fluid is configured to absorb thermal energy from at least one of the inner conductor or the outer conductor. 
     
     
         34 . The assembly of  claim 31 , wherein the choke includes a plurality of apertures disposed therethrough, the plurality of apertures forming at least a portion of the return lumen.