Patent ID: 8934989
Filing Date: 2015-01-13
Classification: A61B

Abstract:
1. A device for transmitting radio-frequency energy for the ablation of biological tissue comprising: an outer elongated electrically conductive tubular member having an axial lumen, a distal end, and a proximal end; an inner elongated electrically conductive tubular member disposed in a spaced apart relationship within the lumen of the outer tubular member to define a wave guide configured for the transmission of radio-frequency (RF) energy in the microwave frequency range and above, the inner member having a distal end and a proximal end; an antenna electrically coupled to at least the distal end of the inner member and adapted to receive and radiate the RF energy for the ablation of biological tissues, the antenna having an outer surface; and at least two layers of dielectric medium arranged in a stack circumferentially around the outer surface of the antenna and configured to provide a dielectric gradient in a direction extending radially outward from the antenna between the antenna and the surrounding tissue in order to reduce reflection from the tissue, the layers being of different dielectric media which have different dielectric constants.