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.

An electrosurgical instrument for delivering microwave energy to biological tissue, in which a pair of conductive tuning elements are mounted in a radiating instrument tip to shape a microwave radiation profile of the instrument so that the radiation profile is constrained around the instrument tip. Such tuning elements may result in a radiation profile that is substantially spherical around the instrument tip, providing a well-defined ablation volume. The tuning elements act to improve the efficiency with which microwave energy can be delivered into target tissue.

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.

Embodiments of the invention provide an energy conveying structure for delivering RF and/or microwave energy to an electrosurgical instrument, where the energy conveying structure is incorporated into an insertion tube of a surgical scoping device (e.g. endoscope, laparoscope or the like). The insertion tube is a flexible conduit that is introduced into a patient's body during an invasive procedure, and can include an instrument channel and an optical channel. The energy conveying structure may be a layered coaxial structure that formed a liner that fits within the scoping device, e.g. within an instrument channel. Alternatively, the energy conveying structure may be a coaxial structure integrally formed as part of the flexible conduit.

A medical microwave delivery system comprises a microwave generator for providing microwave energy, wherein the microwave generator is electrically isolated from an electrical earth of the medical microwave delivery system, a coaxial cable configured to transfer microwave energy from the microwave generator, and a ferrite element configured to at least partially surround at least part of the coaxial cable.

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 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.

A microwave ablation antenna assembly (20) incorporates a choke assembly (40) having a dielectric element (42) and a conducting element (48). The conducting element (48) is chosen from a group of elements of fixed length, but with differing electrical lengths for providing cancellation properties for different wavelengths of microwave energy.

An electrosurgical instrument having a microwave ablation antenna dimensioned to be suitable for insertion into a pancreas via a surgical scoping device, to provide a rapid and accurate alternative to known RF ablation techniques. The instrument comprises a radiating tip portion connected at a distal end of a flexible coaxial cable that conveys microwave energy. The radiating tip portion comprises a proximal coaxial transmission line for conveying the microwave energy and a distal needle tip mounted at a distal end of the coaxial transmission line, wherein the distal needle tip operates as a half wavelength transformer. The length of the radiating tip portion may be in the range from 5 mm to 80 mm.

A cable assembly includes a rigid portion, a flexible central portion, and a radiating portion. The rigid portion is configured to couple to a source of electrosurgical energy and to prevent fluid ingress towards the source of electrosurgical energy. The flexible central portion extends from the rigid portion and includes an inner conductor, a dielectric disposed about the inner conductor, and a conductive braid disposed about the dielectric. The radiating portion extends from the central portion and is configured to deliver electrosurgical energy to tissue.