Electrosurgical forceps in which one or more pairs of non-resonant unbalanced lossy transmission line structures are arranged on the inner surfaces of the jaws of the forceps provide both (i) active and return electrodes for a radiofrequency (RF) signal, and (ii) lossy structures for delivering a microwave signal into biological tissue in conjunction with a mechanical gripping arrangement for applying pressure to material held within the jaws. The location of the pairs of transmission lines on the jaws of the forceps and the selection of the material of the jaws is arranged to ensure that any biological tissue gripped by the jaws become the propagation medium for the RF signal and the medium into which the microwave signal is lost.

A method for forming a resonating structure within a body lumen, the method including advancing a flexible microwave catheter into a body lumen of a patient, the flexible microwave catheter including a radiating portion at the distal end of the flexible microwave catheter, the radiating portion configured to receive microwave energy, and at least one centering device proximate the radiating portion configured to deploy radially outward from the flexible microwave catheter; positioning the radiating portion near tissue of interest; deploying the at least one centering device radially outward from the flexible microwave catheter within the body lumen such that a longitudinal axis of the radiating portion is substantially parallel with and at a fixed distance from a longitudinal axis of the body lumen near the targeted tissue; and delivering microwave energy to the radiating portion such that a circumferentially balanced resonating structure is formed with the body lumen.

An embodiment of system for intrabody treatment of a treatment location in a body of a treated patient is disclosed. The system may include deploying at least two transmission points of a multi point probe to a proximity with the treatment location in the body. A transmission pattern may be selected that defines, for each of the transmission points, a respective signal of a plurality of transmission signals. The transmission pattern may form at least one interaction between the respective signals. The interaction may form a hot spot at the treatment location. A plurality of transmission signals may be delivered from the transmission points.

A microwave delivery device, including a coaxial feedline having an inner conductor, an inner dielectric insulator coaxially disposed about the inner conductor, and an outer conductor coaxially disposed about the inner dielectric, and a radiating portion operably coupled to a distal end. The radiating portion includes a radiating portion inner conductor operable coupled to and extending from a distal end of the coaxial feedline inner conductor, a shielding outer conductor helically wrapped about the radiating portion inner conductor and operably coupled to the coaxial feedline outer conductor; and a shielding dielectric positioned between the radiating portion inner conductor and the shielding outer conductor wherein the width of the shielding outer conductor varies according to the longitudinal position thereof along the coaxial feedline inner conductor, and a cap operably coupled to a distal end of the radiating portion inner conductor and the shielding outer conductor to provide an electrical connection therebetween.

Electrosurgical forceps in which one or more pairs of non-resonant unbalanced lossy transmission line structures are arranged on the inner surfaces of the jaws of the forceps provide both (i) active and return electrodes for a radiofrequency (RF) signal, and (ii) lossy structures for delivering a microwave signal into biological tissue in conjunction with a mechanical gripping arrangement for applying pressure to material held within the jaws. The location of the pairs of transmission lines on the jaws of the forceps and the selection of the material of the jaws is arranged to ensure that any biological tissue gripped by the jaws become the propagation medium for the RF signal and the medium into which the microwave signal is lost.

A microwave system comprises a microwave generator and a microwave cable apparatus comprising a coaxial cable having a diagonally-angled end surface, wherein the microwave generator is configured to provide microwave energy to the cable apparatus at a frequency that provides directional radiation of microwave energy having a desired directionality from the diagonally-angled end surface.

A microwave delivery device, including a coaxial feedline having an inner conductor, an inner dielectric insulator coaxially disposed about the inner conductor, and an outer conductor coaxially disposed about the inner dielectric, and a radiating portion operably coupled to a distal end. The radiating portion includes a radiating portion inner conductor operable coupled to and extending from a distal end of the coaxial feedline inner conductor, a shielding outer conductor helically wrapped about the radiating portion inner conductor and operably coupled to the coaxial feedline outer conductor; and a shielding dielectric positioned between the radiating portion inner conductor and the shielding outer conductor wherein the width of the shielding outer conductor varies according to the longitudinal position thereof along the coaxial feedline inner conductor, and a cap operably coupled to a distal end of the radiating portion inner conductor and the shielding outer conductor to provide an electrical connection therebetween.

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 method and system capable of applying microwave therapy guided by thermoacoustic imaging and/or thermoacoustic thermometry is disclosed. The system includes a thermoacoustic imaging system and/or a thermoacoustic thermometry system that generate(s) a map of a region of interest; and a microwave therapy system that targets the region of interest using the 5 map, and that applies the microwave therapy to the targeted region of interest. Treatment of the targeted region of interest may be employed by the microwave therapy system using real-time feedback from the thermoacoustic imaging system and/or the thermoacoustic thermometry system. Imaging and therapy may be automatically co-registered.

A coupler for coupling a flexible coaxial cable, a fluid cooling system and the outer sheath of a catheter, the coupler including a fluid coupler body having a fluid inlet, a fluid outlet, a bypass bulb, an outer sheath, and a fluid sealing system housed in the fluid coupler body. The fluid sealing system includes a distal sealing diaphragm and a proximal sealing diaphragm configured to form a fluid-tight seal with the fluid coupler body.