Microwave antenna having a curved configuration

Abstract

A microwave antenna having a curved configuration is described herein. The antenna portion is formed into various shapes whereby the antenna substantially encloses, by a partial or complete loop or enclosure, at least a majority of the tissue to be irradiated. When microwave energy is delivered through the antenna, the curved configuration forms an ablation field or region defined by the curved antenna and any tissue enclosed within the ablation region becomes irradiated by the microwave energy. The microwave antenna is deployed through one of several methods, and multiple curved antennas can be used in conjunction with one another. Moreover, RF energy can also be used at the distal tip of the antenna to provide a cutting tip for the antenna during deployment in tissue.

1 . A microwave antenna assembly, comprising:
 a feedline including an inner conductor, an outer conductor and an inner insulator disposed therebetween; and   a radiating portion including a dipole antenna having an operative length and an inductor, the inductor disposed within the inner conductor of the feedline;   wherein the inductor is configured to adjust the operative length of the dipole antenna based on switching occurring between a first frequency and a second frequency.   
     
     
         2 . The microwave antenna assembly according to  claim 1 , wherein the dipole antenna includes a first pole and a second pole, the first pole including at least a portion of the inner conductor and the second pole including at a least a portion of the outer conductor. 
     
     
         3 . The microwave antenna assembly according to  claim 2 , wherein the first pole includes a proximal portion having a first predetermined length and a distal portion having a second predetermined length. 
     
     
         4 . The microwave antenna assembly according to  claim 3 , wherein the distal portion includes the inductor disposed on a proximal end thereof. 
     
     
         5 . The microwave antenna assembly according to  claim 4 , wherein the inductor blocks microwave energy from reaching the distal portion at the first frequency. 
     
     
         6 . The microwave antenna assembly according to  claim 5 , wherein the inductor passes the microwave energy to the distal portion at the second frequency. 
     
     
         7 . A method for forming a lesion, the method comprising the steps of:
 providing a microwave antenna assembly including a radiating portion having a dipole antenna that includes an operative length and an inductor;   supplying microwave energy to the microwave antenna assembly between a first frequency and a second frequency; and   adjusting the operative length of the dipole antenna based on switching occurring between the first and second frequencies supplied thereto to adjust at least one property of the lesion.   
     
     
         8 . The method according to  claim 7 , wherein the at least one property of the lesion is selected from the group consisting of shape, diameter, and depth. 
     
     
         9 . The method according to  claim 7 , wherein the dipole antenna of the providing step further includes a first pole and a second pole, the first pole including at least a portion of the inner conductor and the second pole including at a least a portion of the outer conductor and the inductor is disposed between the proximal portion and the distal portion. 
     
     
         10 . The method according to  claim 7 , further comprising the step of blocking the microwave energy from reaching the distal portion at the inductor at the first frequency. 
     
     
         11 . The method according to  claim 7 , further comprising the steps of passing the microwave energy to the distal portion through the inductor at the second frequency.