Abstract: Embodiments of the invention provide a hollow cable for conveying radiofrequency and/or microwave frequency energy to an electrosurgical instrument that can fit within, e.g. slide relative to, the hollow cable. The hollow cable provides a bipolar electrical connection to the electrosurgical instrument that is maintained when the electrosurgical instrument is rotated relative to the hollow cable. The cable may comprise a hollow coaxial transmission line having a rotatable component mounted at its distal end. The rotatable component comprises a longitudinal passageway continuous with the hollow coaxial transmission line. The rotatable component is rotatable relative to the transmission line and comprises a first and second conductive portions that are respectively electrically connected to first and second terminals on the coaxial transmission line and which are configured to maintain an electrical connection with their respective terminal when rotated relative to the coaxial transmission line.

Abstract: Various embodiments provide an electrosurgical instrument for delivering electromagnetic (EM) energy and ultrasonic vibrations for treating biological tissue. The electrosurgical instrument comprises: an instrument shaft arranged to convey EM energy and an electrical signal for driving a magnetostrictive ultrasound transducer; a distal end assembly arranged at a distal end of the instrument shaft to receive the EM energy from the instrument shaft and deliver the EM energy from the distal end assembly for tissue treatment; and a magnetostrictive ultrasound transducer arranged to receive the electrical signal from the instrument shaft and generate ultrasonic vibrations around the distal end assembly for tissue treatment. Other embodiments provide an electrosurgical generator, and an electrosurgical apparatus comprising the instrument and generator.

Abstract: 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.

Abstract: The invention provides an electrosurgical instrument for delivering radiofrequency and microwave energy to biological tissue in order to cut and coagulate the tissue. The electrosurgical instrument comprises a coaxial transmission line for conveying radiofrequency (RF) energy and microwave energy, and an energy delivery tip coupled to a distal end of the coaxial transmission line. The energy delivery tip comprises: a first electrode electrically coupled to an inner conductor of the coaxial transmission line and protruding beyond a distal end of an outer conductor of the coaxial transmission line; a second electrode electrically coupled to the outer conductor of the coaxial transmission line and extending coaxially along a portion of the first electrode; and a dielectric body disposed between the first electrode and second electrode. The first electrode comprises a projecting nib that protrudes beyond a distal end of the dielectric body.

Abstract: The present invention relates to a pulse generating circuit for an electrosurgical generator, for generating a waveform suitable for causing electroporation of biological tissue. The pulse generating circuit comprises a voltage source connectable to a load via a switching element, and an open circuit coaxial transmission line connected between the switching element and the voltage source to be charged by the voltage source when the switching element is in an OFF state and to be discharged when the switching element is in an ON state. The switching element comprises a plurality of series connected avalanche transistors, and a trigger pulse generator configured to generate a trigger pulse to activate the plurality of series connected avalanche transistors. Furthermore, the impedance of the coaxial transmission line is configured to match a sum of (i) the impedance the plurality of series connected avalanche transistors, and (ii) the impedance of the load.

Abstract: Sterilisation apparatus comprising a sterilisation instrument configured to be inserted through the instrument channel of a surgical scoping device and a withdrawal device for withdrawing the sterilisation instrument from the instrument channel at a predetermined rate. The sterilisation instrument comprises an elongate probe having a probe tip with a first electrode and a second electrode arranged to produce an electric field from received RF and/or microwave frequency EM energy. In operation the instrument may disinfect an inner surface of the instrument channel by emitting energy whilst being withdrawn through the channel.

Abstract: 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.

Abstract: A bipolar pulse generating circuit for an electrosurgical generator generates a waveform for electroporation of biological tissue comprising a voltage source connectable to a load via a switching element, and a coaxial transmission line having an inner conductor separated from an outer conductor. The inner conductor first end is connected between the switching element and the voltage source and second end is in an open circuit condition, whereby the line is charged when the switching element is OFF and discharged when the element is ON. The bipolar pulse generating circuit has an output connectable to the load, wherein the first output supports a positive pulse when the line discharges, and a second output supports a negative pulse when the line discharges. The impedance of the coaxial transmission line matches a sum of impedance of the switching element, the load at the first output, and the load at the second output.

Abstract: Various embodiments provide an introducer for introducing an electrosurgical instrument into a body of a patient. The introducer comprises: a tubular member defining a lumen through which the electrosurgical instrument is insertable; and a cooling assembly configured to remove heat from the tubular member. Other embodiments provide an electrosurgical system comprising an electrosurgical instrument and an introducer.

Abstract: Various embodiments provide an electrosurgical apparatus for treating biological tissue with microwave energy. The apparatus comprises: a microwave energy signal generator for generating a microwave energy waveform; an electrosurgical instrument arranged to deliver the microwave energy waveform from a distal end thereof for tissue treatment; and a controller in communication with the microwave energy signal generator. The microwave energy signal generator is configured to deliver the microwave energy waveform as one microwave energy signal pulse. The controller is configured to control the profile of the one microwave energy signal pulse to cause ablation or coagulation of the biological tissue and to substantially prevent the one pulse from causing heat to build-up in the electrosurgical instrument.

Abstract: 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.

Abstract: A microwave amplifier having a load network which provides more efficient amplification of a low power microwave frequency signal. The amplifier comprises a transistor and a load network coupled to the transistor output to shape a waveform of an amplified microwave signal at the transistor current source plane. The load network comprises: a fundamental matching network to provide impedance matching at a fundamental frequency; a half-wave transmission line for a second harmonic frequency disposed between the transistor output and the fundamental matching network; a quarter-wave stub and a five-quarter-wave stub for a third harmonic frequency arranged on the half-wave transmission line to provide an open circuit condition at the third harmonic; and a quarter-wave stub for the second harmonic frequency and a quarter-wave stub for the fundamental frequency, arranged on the half-wave transmission line to provide a short circuit condition at the second harmonic frequency.

Abstract: An electrosurgical instrument for applying to biological tissue RF electromagnetic energy and/or microwave frequency EM energy, wherein the instrument tip has a protective hull with a smoothly contoured convex undersurface facing away from a planar body, and wherein the planar body has a tapering distal edge, and wherein an underside of the planar body extends beyond the protective hull at the tapering distal edge. Also disclosed herein is an interface joint for integrating into a single cable assembly all of (i) a fluid feed, (ii) a needle movement mechanism, and (iii) an energy feed (e.g. a coaxial cable), and a torque transfer device for permitting controlled rotation of the cable assembly within the instrument channel of an endoscope. The interface joint and torque transfer device may be integrated as a single component.

Abstract: 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.

Abstract: 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.

Abstract: An electrosurgical instrument with a radiating tip portion having a relative permeability and/or relative permittivity that is selected to provide an electrical length for the radiating tip portion that enables effective delivery into biological tissue of microwave EM energy supplied thereto, at two or more frequencies of choice. The instrument has a radiating tip portion disposed to receive microwave EM energy from a coaxial cable, the radiating tip portion having a first effective relative permeability at a first frequency and a second effective relative permeability at a second frequency.

Abstract: An interface joint with one or both of a needle actuation mechanism or an integrated shaft rotation mechanism. The interface joint comprises a flexible shaft between a housing and an electrosurgical instrument, e.g. for conveying power and/or fluid therebetween. The needle actuation mechanism comprises an actuation rod extending out of the housing and an actuator movably mounted on the housing. The shaft rotation mechanism comprises a rotation actuator rotatably mounted on the housing and operably coupled to the flexible shaft. Providing an integrated shaft rotation mechanism may obviate the need for a separate torque transmission unit. The improved needle actuation mechanism may use a pivoting connection to enable longer needle extension distances to be achieved for a given actuation distance.

Abstract: An electrosurgical snare, e.g. suitably sized for insertion down the instrument channel of an endoscope, arranged to radiate microwave frequency energy (e.g. having a frequency greater than 1 GHz) from an elongate conductive element within an area encircled by a retractable loop. The elongate conductive element and retractable loop may be independently slidable relative to a snare base at a distal end of a sleeve to provide an appropriate device configuration. By controlling the shape of the emitted microwave field, the risk of collateral thermal damage can be reduced.

Abstract: An electrosurgical instrument capable of supporting resonance of microwave energy at multiple frequencies. The instrument comprises a coaxial cable and a radiating distal tip portion arranged to receive microwave energy from the coaxial cable. The radiating tip portion consists of a dielectric material having an electrical length selected in conjunction with its dielectric properties at three or more frequencies of microwave energy to support resonance at each frequency. By providing a single device that can effectively couple microwave energy into biological tissue at three or more frequencies, tissue ablation can be performed rapidly with accuracy. The instrument may be used in an apparatus that includes a generator arranged to supply microwave energy at three or more different frequencies.

Abstract: Skin treatment apparatus comprising an energy applicator structure configured to establish heating or ablation at a predetermined and controllable (i.e. selectable) depth below a surface of skin tissue with which it is in contact. The applicator structure may receive a cooling medium and microwave frequency electromagnetic energy, which provide a combined treatment effect that results in heating or ablation in a zone beneath the skin surface. The applicator may be a waveguide (e.g. waveguide horn antenna) with internal shielding configured to provide a substantially uniform heating effect. The applicator may include a thermal camera to monitor treatment.