A radio frequency (RF) or microwave energy applicator device (10) for applying radio frequency or microwave radiation to a target (22), the applicator (10) comprising: an energy generator module (12) for generating RF or microwave energy, wherein the energy generator module (12) comprises an energy output (16) for outputting said generated energy; a radiating structure (14) for radiating RF or microwave radiation to the target wherein the radiating structure (14) comprises an energy input (18), wherein the energy generator module (12) and the radiating structure (14) are coupled to provide the energy output (16) of the energy generator module (12) and the energy input (18) of the radiating structure (14) at a transmission interface (20); wherein the transmission interface (20) comprises at least one transmission feature comprising a size, dimension and/or shape selected so that at least part of the energy provided to the transmission interface (20) is transmitted to the radiating structure (18) and/or at least part of the energy provided to the transmission interface (20) is reflected.

A microwave applicator for insertion into living body tissue for use in microwave coagulation and ablation treatments includes a microwave transmission line extending between an attachment end of the applicator and an antenna toward an insertion end of the applicator with an outer conductive sleeve forming an enclosed cooling fluid space around the transmission line. Circulation of cooling fluid is guided in the cooling fluid space by a guide sleeve. A fluid circulation system provides a plurality of fluid supply connectors and fluid return connectors which can be connected and used with any number of applicators between one and the number of the fluid supply connectors provided by the system. A portion of the applicator inserted into the tissue can stick to the tissue to stabilize the applicator during treatment. A warning marking on the applicator can be used during track ablation to prevent ablation of the patient skin tissue.

A microwave antenna has a radiating portion connected by a feedline to a power generating source, e.g., a generator. Proximal and distal radiating portions of the antenna assembly are separated by a junction member. A reinforcing member is disposed within the junction member to increase structural rigidity.

An isolating circuit for electrosurgical generator arranged to produce radiofrequency (RF) energy and microwave energy for treating biological tissue. The generator has an RF channel and a microwave channel which are combined at signal combiner to enable the RF energy and microwave energy to be delivered into tissue along a common feed path. The isolating circuit comprises a tunable waveguide isolator at a junction between the microwave channel and signal combiner, and can include a capacitive structure between a ground conductor of the signal combiner and a conductive input section of the waveguide isolator to inhibit coupling of the RF energy and leakage of the microwave energy. The isolating circuit can combine into a single tunable unit all the necessary components to isolate the microwave and RF channels from one another whilst providing a high withstanding voltage.

A microstrip impedance transformer that permits efficient (i.e. low loss) coupling of a microwave feed line (e.g. a conventional 50Ω coaxial cable) to an instrument cable, where the instrument cable has a lower impedance (e.g. in the range 12 to 14Ω) and includes an internal passageway. The microstrip impedance transformer is configured to perform impedance matching between the microwave feed line and the instrument cable in a manner that does not adversely affect a separate feed, e.g. for delivering fluid, into the internal passageway.

The invention comprises novel microwave antennas wherein the microwave field profile generated by an antenna is tailored and optimized for a particular clinical application. The antennas disclosed herein incorporate one or more additional elements called shaping elements that use unique properties of microwaves such as interaction of a microwave field with one or more conductive or non-conductive elements to shape or redistribute the microwave field. Such shaping elements may be used to reduce the undesired backward coupling of the emitted microwave field to the transmission line. Such shaping elements may be used to increase the power efficiency of the antenna. The invention also discloses devices and methods for treating tissue with microwave energy emitted from the antennas for use in applications such as destroying a soft tissue by microwave ablation.

A circular microwave ablation antenna is provided with a chamber for accommodating the coaxial cable and the conduit, the chamber and the conduit extend forward to the front end of the antenna. An emission window of the antenna is at least partially located in the conduit to enable the cooling medium to cool the emission window area of the antenna. The conduit of the microwave emission area is made of an insulation material, so that the microwave can radiate outward, and the rest of the conduit is made of a microwave shielding material. The choke ring located at the rear side of emission area is hermetically fixed to the conduit, so that the choke ring acts to block the microwave. A gap exists between the choke ring and the needle bar, and the gap is used for the backflow of the cooling medium.

Provided herein are devices, systems, 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, devices, systems, and methods are provided for delivering energy to difficult to access tissue regions (e.g. central or peripheral lung tissues), and/or reducing the amount of undesired heat given off during energy delivery.

A system for use in tumor ablation. The tumor ablation system includes a microwave antenna which has a channel along the length thereof. There are two ports proximate the proximal end of the microwave antenna. The first port is an energy port configured to connect the antenna to an energy source. The second port is a fluid port configured to connect the channel to a fluid delivery mechanism. The system also includes an inflatable balloon configured to be attached to a distal end of the antenna. The channel permits fluid access from the fluid port to an interior of the balloon for inflation thereof.

An ablation probe tip (100) having a shaft (102) with an insertion end (104). The shaft (102) includes a coaxial antenna (110). A center of ablation (124) is located within the shaft (102) near the insertion end (104). A heat transfer layer (130) surrounds the coaxial antenna (110). A thermal reservoir (134) at least partially surrounds the heat transfer layer (130). A method for using the ablation probe tip (100) includes predetermining an optimal temperature for the heat transfer layer (130), and the thermal reservoir (134) cooling the heat transfer layer (130) to no higher than the optimal temperature. The ablation probe tip (100) may be part of an ablation probe system (50) that includes an ablation source (60) that provides ablation means (62) to the ablation probe tip (100).