The present invention relates to comprehensive systems, devices 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, systems, devices, and methods are provided for treating a tissue region (e.g., a tumor) through application of energy.

A helical antenna structure for use in an electrosurgical instrument. The helical antenna structure is connectable to inner and outer conductors of a coaxial transmission line, and can act as both a radiating antenna or applicator structure, and also in a mode where an electric field is generated between its electrodes. In this way, the helical antenna structure may be used both for argon plasma coagulation, and deep tissue coagulation, as well as providing means for delivering a fluid, e.g. a therapeutic fluid such as adrenaline. This may be achieved through the use of helically arranged electrodes and a channel for gas to flow. This device is also used to deliver adrenaline and RF/microwave energy.

An electrosurgical vessel sealing device that can seal biological vessels using a confined microwave field that yields a well-defined seal location with low thermal margin. The device comprises a pair of jaws that are movable relative to each other to grip biological tissue. A blade for cutting the gripped tissue is slidable between the jaws. A coplanar microstrip antenna is mounted on the inner surface of one or both of the pair of jaws to emit microwave energy into the gap therebetween. The device may comprise a separate dissector element to enable fine tissue cutting and dissection to be performed.

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.

A variable-length microwave ablation probe is provided. The probe is configured to have a range of resonant frequencies. The probe includes a microwave antenna, an outer conductor, and a cap. The probe further includes a radiation window that is at least partially transparent to microwave energy. The distal boundary of the outer conductor or the proximal boundary of the cap varies in distance from the probe distal end. The probe can have a choke length, an arm length, a radiating portion length, and a cap length. The lengths can each affect the resonant frequency of the antenna. Some examples provide a variable choke length, a variable arm length, a variable radiating portion length, and/or a variable cap length.

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.

Microwave ablation applicators and methods for manufacturing the microwave ablation applicators are disclosed. A microwave ablation applicator includes a feed-line segment, a step-down segment, and a radiator base segment. The feed-line segment includes a first inner conductor, a first dielectric disposed on the first inner conductor, and a first outer conductor disposed on the first dielectric. The step-down segment includes a second inner conductor, a second dielectric disposed on the second inner conductor, and a second outer conductor disposed on the second dielectric. The radiator base segment includes a third inner conductor disposed on the third inner conductor, a third outer conductor disposed on the proximal end of the third dielectric so as to form a feed gap at a distal end of the radiator base segment, a balun dielectric disposed on the third outer conductor, and a balun outer conductor disposed on the balun dielectric.

An electrosurgical vessel sealing device that can seal biological vessels using a confined microwave field that yields a well-defined seal location with low thermal margin. The device comprises a pair of jaws that are movable relative to each other to grip biological tissue. A blade for cutting the gripped tissue is slidable between the jaws. A coplanar microstrip antenna is mounted on the inner surface of one or both of the pair of jaws to emit microwave energy into the gap therebetween. The device may comprise a separate dissector element to enable fine tissue cutting and dissection to be performed.

Various embodiments provide an electrosurgical instrument comprising: a flexible coaxial transmission line arranged to convey microwave energy; a radiating tip portion connected at a distal end of the flexible coaxial transmission line and configured to receive the microwave energy, the radiating tip portion comprising: a distal coaxial transmission line for conveying the microwave energy; and a needle tip mounted at a distal end of the distal coaxial transmission line, the needle tip being arranged to deliver the microwave energy into biological tissue; and a heat sink mounted at an interface between the flexible coaxial transmission line and radiating tip portion. The heat sink is in thermal communication with a proximal end of the distal coaxial transmission line and configured to draw thermal energy from the radiating tip portion. Also, a maximum outer diameter of the radiating tip portion is smaller than an outer diameter of the flexible coaxial transmission line. An associated electrosurgical system is also disclosed.

A microwave ablation system comprises a generator, a generator cable, and a microwave ablation device. The generator comprises a generator output port having a generator output port impedance. The generator cable has a generator cable impedance that is matched to the generator output port impedance within a degree of tolerance within a predetermined frequency range. The microwave ablation device comprises a coaxial cable that has a coaxial cable impedance and is coupled to the generator output port by way of the generator cable. Within the predetermined frequency range, the coaxial cable impedance is lower than at least one of the generator output port impedance or the generator cable impedance by at least a predetermined amount that exceeds the degree of tolerance.