A system including a catheter navigable to a location within a patient, a lumen extending through the catheter and ending at the distal end in an orifice, a fluid controller in fluid communication with the lumen of the catheter and capable of supplying a fluid to or removing a fluid from an area proximate the desired location. The control of the fluid in the area proximate the desired location affecting a dielectric constant of the area proximate the desired location. The system includes a microwave energy source, and a microwave ablation probe connected to the microwave energy source, the microwave ablation probe being navigable to a desired location within the patient. Application of energy from the microwave energy source to the microwave ablation probe in an area proximate the desired location having the affected dielectric constant results in a substantially spherical tissue effect in the area proximate the desired location.

It is an object to provide a surgical instrument capable of locally applying microwaves to a minute biological tissue. It has been found that microwaves can be transmitted to a tip of a tapered coaxial body (9) and that microwaves are radiated from the entire central conductor exposed in a major axis direction by decreasing a sectional area (preferably diameter) of a central conductor (1) and a sectional area (preferably inner diameter) of an external conductor gradually or in a step-by-step manner with a ratio between the sectional area (diameter) of the central conductor (1) and the sectional area (inner diameter) of the external conductor being set to be constant, thereby achieving the present invention.

A microwave antenna assembly is disclosed. The antenna assembly includes a feedline having an inner conductor, an outer conductor and an inner insulator disposed therebetween. A radiating portion is also included having an unbalanced dipole antenna including a proximal portion and a distal portion that are of different lengths. The proximal portion includes at least a portion of the inner conductor and the inner insulator and the distal portion includes a conductive member.

An energy delivery system includes a transmission member, an antenna at a distal end of the transmission member, a jacket surrounding the transmission member and the antenna, a fluid channel between the transmission member and the jacket, and a plug disposed at the distal end of the transmission member and a proximal end of the antenna. The plug is configured to prevent migration of a cooling fluid from the fluid channel to a cavity between the antenna and the jacket.

A shaft assembly for a microwave ablation applicator having a shaft assembly and an antenna assembly located within the shaft assembly is disclosed. The shaft assembly comprises an elongate shaft which extends from a first end to a second end thereof and an applicator tip mounted on the second end of the elongate shaft.

A system including a catheter navigable to a location within a patient, a lumen extending through the catheter and ending at the distal end in an orifice, a fluid controller in fluid communication with the lumen of the catheter and capable of supplying a fluid to or removing a fluid from an area proximate the desired location. The control of the fluid in the area proximate the desired location affecting a dielectric constant of the area proximate the desired location. The system includes a microwave energy source, and a microwave ablation probe connected to the microwave energy source, the microwave ablation probe being navigable to a desired location within the patient. Application of energy from the microwave energy source to the microwave ablation probe in an area proximate the desired location having the affected dielectric constant results in a substantially spherical tissue effect in the area proximate the desired location.

The present invention relates to comprehensive systems, devices and methods for delivering energy to tissue for a wide variety of applications, including medical procedures (e.g., tissue ablation, resection, cautery, vascular thrombosis, treatment of cardiac arrhythmias and dysrhythmias, electrosurgery, tissue harvest, etc.). In certain embodiments, systems, devices, and methods are provided for treating a tissue region (e.g., a tumor) through application of energy.

A microwave ablation device including a cable assembly configured to connect a microwave ablation device to an energy source and a feedline in electrical communication with the cable assembly. The microwave ablation device further includes a balun on an outer conductor of the feedline, and a temperature sensor on the balun sensing the temperature of the balun.

An electrosurgical instrument for delivering electromagnetic energy to biological tissue, the instrument comprising an active tip having an electrically conductive protective hull mounted on an underside thereof. The hull has a smoothly contoured convex undersurface, and is formed as a shaped piece of electrically conductive bio-compatible material having a low coefficient of friction with biological tissue (e.g. stainless steel) which has the dual function of (i) physically protecting tissue that lies underneath the active tip, and (ii) providing an electrical connection between a coaxial feed line and the active tip.

A microwave antenna assembly is disclosed. The antenna assembly includes a feedline having an inner conductor, an outer conductor and an inner insulator disposed therebetween. A radiating portion is also included having an unbalanced dipole antenna including a proximal portion and a distal portion that are of different lengths. The proximal portion includes at least a portion of the inner conductor and the inner insulator and the distal portion includes a conductive member.