Electrosurgical devices with balun structure for air exposure of antenna radiating section and method of directing energy to tissue using same

摘要

An energy applicator for directing energy to tissue includes a feedline having an inner conductor, an outer conductor and a dielectric material disposed therebetween, and an antenna assembly having a radiating section operably coupled to the feedline. The energy applicator also includes a first balun structure configured to substantially confine energy to the radiating section when the energy applicator is energized and disposed in tissue, and a second balun structure configured to substantially prevent energy emitted from the radiating section from propagating proximal to the second balun structure along the feedline when the energy applicator is energized but not disposed in tissue.

主权项

1. An energy applicator for directing energy to tissue, comprising:
a feedline having an inner conductor, an outer conductor coaxially disposed around the inner conductor, and a dielectric material disposed therebetween; an antenna assembly having a radiating section operably coupled to the feedline; a first balun structure configured to substantially confine energy to the radiating section when the energy applicator is energized and disposed in tissue, wherein the first balun structure includes a first balun and a second balun disposed so as to at least partially overlap the first balun; the first balun including:
a first balun insulator disposed around a distal portion of the outer conductor;a first balun conductor disposed around at least a portion of the first balun insulator; the second balun including:
a second balun insulator disposed so as to at least partially overlap a proximal portion of the first balun conductor;a second balun conductor electrically coupled to the outer conductor; and a second balun structure configured to substantially prevent energy emitted from the radiating section from propagating proximal to the second balun structure along the feedline when the energy applicator is energized but not disposed in tissue.