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 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 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 radially spaced from the insulator and 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 flow of a cooling fluid.

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.

An energy delivery system includes an RF synthesizer circuit configured to generate an RF electric signal and a preamplification stage operably coupled to the RF synthesizer circuit. The preamplification stage has at least one attenuator. A board controller is operably coupled to the attenuator of the preamplification stage that is configured to modify a gain setting of the attenuator. An output connection is configured to provide a low-power signal or a high-power signal based on at least the RF electric signal and the gain setting. The low-power signal or high-power signal is provided to an RF applicator configured to couple an alternating RF electric field to animal tissue.

Surgical cutting apparatus having a treatment channel and a measurement channel for conveying microwave energy from a source to an antenna at a cutting edge. The measurement channel operates at lower power than the treatment channel for determining when higher energy can be safely applied. The apparatus may deliver microwave radiation at differing frequencies to one or more antennas at the cutting edge, e.g. to provide different treatment effects. The source may generate an output for an antenna whose frequency can be selected e.g. for most efficient operation. Selection may be automatic based on detected magnitude and phase of reflected signals during a frequency sweep of a forward signal. Power delivered to tissue via the cutting element may be manually boosted to deal with large blood vessels. The apparatus may include a reflected power monitor for recognising behaviour in reflected signals received from the antenna to trigger automatic pre-emptive action.

A microwave ablation device includes a cable assembly, a feedline, and a transmission line. The cable assembly is configured to connect to an energy source. The feedline is in electrical communication with the cable assembly and includes a first temperature sensor. The first temperature sensor is disposed at a first axial location along a length of the feedline and is configured to sense a temperature at the first axial location. The first temperature sensor extends along the length of the feedline. The transmission line extends from the first temperature sensor and is disposed parallel and in contact with an outer conductor of the feedline.

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.

An electrosurgical energy delivery apparatus includes an energy delivery circuit, a control circuit and an energy-harvesting system with a plurality of energy-harvesting circuits and a voltage regulator that provides a regulated DC voltage to the energy delivery circuit and/or the control circuit. The energy delivery circuit receives an electrosurgical energy signal having a primary frequency and selectively provides the electrosurgical energy signal to an energy delivery element. The control circuit connects to the energy delivery circuit and selectively enables the flow of electrosurgical energy to the energy delivery element. The plurality of energy-harvesting circuits each include an energy-harvesting antenna tuned to a particular frequency, a matched circuit configured to receive an RF signal from the energy-harvesting antenna, rectify the RF signal and generate a DC signal, and an energy storage device that connects to the voltage regulator to receive and store the DC signal.