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 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.

An electrosurgical apparatus for treating fluid-filled biological growths by replacing the fluid within the growth with a substance that assists in delivering treatment energy. The treatment energy may be microwave energy or may be thermal energy derived from microwave energy. The apparatus comprises an instrument having a radiating tip portion, and a fluid delivery mechanism for transporting fluid to and from a treatment zone located around the radiating tip portion. The fluid delivery mechanism comprises a rigid insertion element arranged to extend into the treatment zone, whereby fluid can be aspirated from the treatment zone, and a substance injected into the treatment zone to replace the aspirated fluid. The injected substance has dielectric properties selected to facilitate uniform delivery of treatment energy to biological tissue in the treatment zone.

An electrosurgical apparatus for treating fluid-filled biological growths by replacing the fluid within the growth with a substance that assists in delivering treatment energy.

The treatment energy may be microwave energy or may be thermal energy derived from microwave energy. The apparatus comprises an instrument having a radiating tip portion, and a fluid delivery mechanism for transporting fluid to and from a treatment zone located around the radiating tip portion. The fluid delivery mechanism comprises a rigid insertion element arranged to extend into the treatment zone, whereby fluid can be aspirated from the treatment zone, and a substance injected into the treatment zone to replace the aspirated fluid. The injected substance has dielectric properties selected to facilitate uniform delivery of treatment energy to biological tissue in the treatment zone.

An end effector structure for tissue ablation powered by microwave energy source and end effector including a microwave antenna surrounded by a segments from microwave absorbing materials. Microwave absorbing material is a material, transparent to microwave energy impregnated with microwave absorbing particles, and has differing microwave transmission and/or absorption characteristics at different locations along the microwave antenna to apply to the desired bi-tissue, a selective amount of microwave and/or heat energy. Microwave transparent material can be ceramic, silicone, fluorosilicone, fluorocarbon, thermoplastic rubber, ethyline propylene diene monomer, urethane etc. Microwave absorbing particles can be from nickel (Ni), copper (Cu), Aluminum (Al), Ag/Cu; Ag/Al; Ag/Ni; Ag/Glass, nickel-plated graphite, silver-plated aluminum, silver-plated copper, silver-plated nickel, silver-plated glass and pure silver etc.

Devices and methods for treating tissue with microwave energy used in applications such as destroying a soft tissue by microwave ablation and/or creating point, line, area or volumetric lesions. Various embodiments of flexible, low-profile devices are also disclosed where such device can be inserted non-invasively or minimally invasively near or into the target tissue such as cardiac tissue. The devices disclosed herein comprise antennas wherein the field profile generated by an antenna is tailored and optimized for a particular clinical application. The antennas use unique properties of microwaves such as interaction of a microwave field with one or more conductive or non-conductive shaping elements to shape or redistribute the microwave field.

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.

Devices, kits, and methods described herein are usable for medical treatments by generating local maxima using constructive interference of multiple oscillator outputs. Where constructive interference occurs between the oscillator waves, the output signal can have significant strength to cause heating and coagulation at a bleeding vessel, for instance, while at areas with little interaction (or with destructive interference) there is insufficient power dissipated by the output signal to cause heating sufficient to cause coagulating heating.

An electrosurgical device (10) is provided that is operable to deliver microwave energy within a controlled angular expanse to cause targeted tissue ablation. The device (10) comprises a blocking or reflecting material such as cylindrical members (34) that are laterally spaced from the antenna (20) that is operable to emit the microwave energy. The reflecting material creates regions in and/or surrounding the device into which sensors (51), such as thermocouple wires, may be placed to monitor a condition associated with the device or the patient's body.

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.

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.