Monopole tip for ablation catheter
View Patent ↗An ablation catheter apparatus with a monopole antenna that is arranged to provide a relatively uniform electric field and a method for using such an ablation catheter apparatus are disclosed. According to one aspect of the present invention, an ablation catheter includes an elongated flexible tubular member that is adapted to be inserted into the body of a patient, and a transmission line that is disposed within the tubular member. The transmission line has a distal end and a proximal end which is arranged to be connected to an electromagnetic energy source. The catheter also includes a monopole antenna with tip section and a body section that includes a distal end and a proximal end. The tip section and the body section are arranged to produce a relatively uniform electric field around the monopole antenna which is sufficiently strong to cause tissue ablation. The proximal end of the body section of the monopole antenna is arranged to be electrically coupled to the transmission line.
1. An antenna structure, comprising:
an elongated flexible tubular member adapted to be inserted into a patient's body and having a distal end attached to the monopole antenna near the proximal end thereof;
a monopole antenna formed of electrically conductive material and including a substantially hemispherical distal tip operably disposed at a distal end of the ablation device and having a substantially conical shape converging proximally from the distal tip toward a proximal end for forming an outer emission surface from which electromagnetic energy is emitted between the distal and proximal ends in a uniform electromagnetic field pattern about the monopole antenna in response to electromagnetic energy applied to the proximal end thereof; and
an electromagnetic energy conductor disposed within the tubular member and connected to the proximal end of the monopole antenna for transmitting ablation energy thereto, the outer surface of the insulating material encasing the monopole antenna forming a smooth surface transition with an outer surface of the tubular member.