A shaft assembly for a microwave ablation applicator which includes a shaft assembly and an antenna assembly located within the shaft assembly is disclosed. The shaft assembly comprises an elongate shaft which extends from a first end to a second end thereof, and which defines therein a hollow inner volume and a longitudinal axis of the antenna assembly, and an applicator tip mounted on the second end of the elongate shaft. The shaft assembly further includes a coolant delivery tube having a side wall which defines an elongate hollow interior.

An electrosurgical system for treating biological tissue that comprises: an electrosurgical generator to supply microwave energy; a surgical scoping device having a steerable insertion cord for insertion to a treatment site; and an electrosurgical instrument dimensioned to fit within an instrument channel that is located within the insertion cord. The electrosurgical instrument comprises: a flexible coaxial cable arranged to convey the microwave energy; and a radiating tip portion connected at an end of the coaxial cable and configured to receive microwave energy. The radiating tip portion comprises: a coaxial transmission line for conveying the microwave energy; and a needle tip mounted at an end of the proximal coaxial transmission line, wherein the electrosurgical instrument is slidable within the instrument channel to extend the needle tip beyond an end of the instrument channel to puncture biological tissue; the needle tip is arranged to deliver the microwave energy into biological tissue.

A filtering device for use in a medical microwave delivery system is disclosed. The filtering device comprises a DC block and a microwave absorbing element. The microwave absorbing element is disposed around the DC block and/or around one or more elements within the DC block. Also disclosed is a medical microwave delivery system comprising a microwave generator system and the filtering device, wherein the filtering device is coupled to an output of the microwave generator system.

A microwave apparatus comprises: a microwave feed line configured to deliver microwave energy having a selected operational frequency or range of frequencies to a radiating element extending from or coupled to a distal end of the microwave feed line; the radiating element; and a reactive element formed in or on the microwave feed line; wherein the operational frequency or range of frequencies is selected such that the reactive element both provides a desired degree of match between an impedance of the radiating element and an impedance of the microwave feed line, and reduces or eliminates surface currents flowing on a ground of the feed line.

An energy delivery system comprises a transmission member and an antenna at a distal end of the transmission member. The antenna includes a first conductive arm, an insulator extending around the first conductive arm, and a second conductive arm. The second conductive arm includes a coil. The system also comprises a barrier layer surrounding the transmission member and antenna. The barrier layer extends from a proximal portion of the transmission member to a distal portion of the antenna. The system also comprises a jacket surrounding the barrier layer and forming a fluid channel for receipt of a cooling fluid.

An exemplary microwave ablation system is provided. The system may use a switching antenna for both microwave heating of target tissue and microwave radiometry to monitor the temperature of the heated tissue to ensure that the desired temperatures are delivered to adequately treat the target tissue and achieve therapeutic goals. The system may integrate switching components into the switching antenna, which eliminates error from heating of the reference termination and heating of the electrical cables.

Various aspects of the present disclosure are directed toward apparatuses, systems, and methods that may include a microwave ablation probe. The microwave ablation probe may include a feedline having an inner conductor, an outer conductor and a dielectric; and an antenna including a helical arm, the helical arm being electrically connected to the outer conductor of the feedline at a junction point, and a linear arm, the linear arm being electrically connected to the inner conductor of the feedline.

A microwave ablation device including a cable assembly configured to connect a microwave ablation device to an energy source and a feedline in electrical communication with the cable assembly. The microwave ablation device further includes a balun on an outer conductor of the feedline, and a temperature sensor on the balun sensing the temperature of the balun.

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 antenna system for tissue ablation includes an energy transmission member, an antenna body coupled to the energy transmission member, a fluid source, and a choke member comprising an integrally formed choke body and choke connector electrically coupled to the energy transmission member by the choke connector. The choke body defines an outermost portion of the choke member. The choke body has an axial length and the choke connector extends along a majority of the length of the choke body and contacts the choke body along the majority of the length. The choke connector is in direct contact with a fluid from the fluid source. The choke connector is disposed between the choke body and the energy transmission member. The choke connector forms a delivery path for the fluid between the choke body and the energy transmission member. The choke connector and the choke body are a continuous wire mesh.