An electrosurgical apparatus having a feed structure comprising a radiofrequency (RF) channel for conveying RF electromagnetic (EM) radiation from an RF signal generator to a probe and a microwave channel for conveying microwave EM radiation from a microwave signal generator to the probe, wherein the RF channel and microwave channel comprise physically separate signal pathways, wherein the feed structure includes a combining circuit having an input connected to the signal pathway on the RF channel, another input connected to the signal pathway on the microwave channel, and an output connected to a common signal pathway for conveying the RE EM radiation and EM radiation separately or simultaneously to the probe, and wherein the microwave channel includes a waveguide isolator connected to isolate the signal pathway on the microwave channel from the RF EM radiation.

A multicarrier ablation system comprising: an antenna for application to biological tissue; a multi-carrier signal generator configured to provide a forward radio frequency (RF) signal to the antenna, the forward RF signal comprising multiple subcarriers that occupy respective frequencies within a bandwidth of the RF signal; and a monitoring circuit configured to receive a reflected RF signal from the antenna and control the multi-carrier signal generator to adjust one or more parameters of the forward RF signal during an ablation procedure based on the reflected RF signal.

The invention relates to an electrosurgical system for delivering electromagnetic energy at a plurality of frequencies to cause different effects on biological tissue at a treatment site, and in particular to an electrosurgical generator. The electrosurgical generator comprises an electromagnetic signal supply unit for generating microwave energy to be conveyed on each of a plurality of microwave channels, wherein each of the plurality of microwave channels is arranged to convey microwave energy at a different frequency; an output port configured to be connectable to a probe for delivering microwave energy from the plurality of microwave channels; and a signal combiner configured to connect the plurality of microwave channels to the output port, wherein the signal combiner comprises a band stop filter module disposed at a distal end of each of the plurality of microwave channels, wherein the band stop filter module for each microwave channel is configured to block microwave energy at the frequency conveyed on the other microwave channels; and a common signal pathway extending between the output port and a junction at which the plurality of microwave channels are connected.

A combined isolator-diplexer device for supplying radiofrequency (RF) energy and microwave energy obtained from separate sources to a probe via a common signal pathway. The invention combines into a single unit all the necessary components to isolate a microwave channel from an RF channel whilst providing a high withstanding voltage (e.g. greater than 10 kV). The device comprises a waveguide isolator for isolating the microwave channel having a pair of DC isolation barriers arranged therein to provide a pair of series-connected capacitive structures between a ground conductor at an output of the combining circuit and a conductive input section of the waveguide isolator.

Flexible instruments and associated systems and methods are disclosed herein. In some embodiments, a flexible instrument comprises an elongate device having an inner conductor, an outer conductor surrounding the inner conductor, and a dielectric layer insulating the inner conductor from the outer conductor. The flexible instrument further includes a recess formed in the outer conductor. An insert is positioned within the recess and about the inner conductor.

A microwave ablation antenna based on a spiral slot, including a conical ablation needle head and a semi-rigid coaxial needle rod. A front end of the semi-rigid coaxial needle rod is interconnected with a tail end of the ablation needle head. An outer conductor behind a connection is provided with a plurality of optimizable spiral slots for radiation, and a plurality of annular slots are not formed or formed behind the spiral slots for impedance matching and radiation. Energy is transmitted along a semi-rigid co-axis and is efficiently radiated at the slots.

An esophageal ablation system including a positioner, an elongated, flexible shaft extending from the positioner, and a microwave emitter assembly disposed near the distal end of the shaft. The emitter assembly includes one or more microwave antennae and a balloon tor spacing the antennae relative to target tissue. The device may have an inner balloon for deploying the antenna. The systems, devices and methods disclosed are useful for treating Barrett's Esophagus, Esophageal Adenocarcinoma, and Squamous Cell Carcinoma.

An ablation device includes a feedline including an inner conductor having a distal end, an outer conductor coaxially disposed around the inner conductor, and a dielectric material disposed therebetween, an elongated electrically-conductive member longitudinally disposed at the distal end of the inner conductor and having a proximal end, a first balun structure disposed over a first portion of the outer conductor and positioned so that a distal end of the first balun structure is located at a first distance from the proximal end of the electrically-conductive member and a second balun structure disposed over a second portion of the outer conductor and positioned so that a distal end of the second balun structure is located at a second distance from the proximal end of the electrically-conductive member.

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 resection instrument for applying to biological tissue radiofrequency electromagnetic energy has a protective hull comprising a shaped piece of dielectric material mounted to cover an underside of an instrument tip of the instrument. The protective hull acts as a shield to protect tissue that may lie under the instrument tip from damage during treatment. The instrument may be particularly useful in procedures performed in a gastrointestinal tract, where bowel perforation is a concern, or in the pancreas, where damage to the portal vein or the pancreatic duct may occur when a tumor or other abnormality is being resected, dissected or removed.