Abstract: A surgical instrument (100) (e.g. scalpel) is disclosed which has an antenna arranged to emit a substantially uniform microwave radiation field (e.g. having a frequency of 5-100 GHz) at an edge of a cutting element (110) (e.g. blade). The emitted radiation can cauterize tissue e.g. broken blood vessels simultaneously with cutting. The antenna may be integral with the cutting element, e.g. a metallized piece of ceramic attachable at an end of a waveguide (120, 150) to receive radiation therefrom. The cutting element (110) can include a quarter wave transformer to couple power efficiently from the waveguide (120). The instrument can be used with impedance matching apparatus to control the energy delivered into the tissue. Also disclosed is an invasive ablation probe (e.g. insertable through a catheter) having a plurality of radiating elements whose emitted field combine to give a uniform effect at an insertion end of the probe.

Abstract: A biopsy needle (80) having a longitudinal channel (84) formed within an inner conductor (86) of a coaxial antenna is disclosed. The coaxial antenna terminates in a rigid insertion tip (82) e.g. a ceramic cone that is insertable into biological tissue. Microwave energy (e.g. having a frequency of 1 to 100 GHz) delivered to the coaxial antenna is emitted at the insertion tip. The insertion tip may be arranged to match the impedance of the coaxial antenna to a predetermined tissue impedance. The emitted radiation can be used to measure properties of or treat (e.g. ablate) tissue at the insertion tip. Needle biopsy apparatus is also disclosed, in which a microwave energy is controllably delivered to a needle from a microwave generator. The apparatus may include an impedance tuner to dynamically match the impedance of the needle with tissue at the insertion tip.

Abstract: A portable electrosurgical system (100) for treating biological tissue with microwave radiation (e.g. having a frequency between 500 MHz and 60 GHz) is disclosed. The system comprises a hand-held microwave sub-assembly (102) which generates and amplifies a microwave signal (which may be continuous or modulated) for treatment and includes a treatment antenna (116) for delivering the radiation. Diode detectors (120, 122) in the sub-assembly (102) may detect forward and reflected power levels to enable determination of net delivered power. A dynamic impedance matching system may be provided to match energy developed by amplifiers (110, 112) in the sub-assembly (102) to the biological tissue load. A tuning filter (144) and couplers (146, 148, 150, 152) for extracting magnitude and phase information from the microwave signal are thus provided in the sub-assembly.

Abstract: Skin tissue measurement/treatment apparatus (40) for controllably delivering electromagnetic radiation having a frequency of 10 GHz or more directly to a localised region of skin tissue via a monopole antenna (44) adapted to penetrate the skin surface. One embodiment includes an applicator (152) having a plurality of independently controllable monopole antennas (158) protruding therefrom for selective treatment/measurement of an area of skin. Treatment may be activated based on the complex impedance of tissue in the localised region calculated by determined the magnitude and phase of reflected power relative to a reference signal. The power level of the generated electromagnetic radiation may be adaptively controlled based on the detection of net power delivered to the skin tissue.

Abstract: A surgical antenna for radiating microwave energy (e.g. frequency 500 MHz to 60 GHz) from a e.g. ceramic insertion tip (60) into biological tissue is disclosed. The tip is provided at the end of an elongate body which delivers the microwave energy to the tip via an inner conductor (30), an outer conductor (20) surrounding the inner conductor and a dielectric material (50) therebetween. The impedance of the insertion tip (60) is selected to improve impedance matching with the complex conjugate of the complex impedance of the tissue at a treatment frequency. For example the insertion tip may act as or include at least one quarter wavelength impedance transformer. By closely matching the antenna's impedance to the tissue, dynamic tuning (if used) can be performed much more efficiently. Impedance matching at the tip can also focus the radiated energy distribution.

Abstract: A tissue resurfacing system has a handheld surgical instrument with a gas conduit (38) which terminates in an exit nozzle (180N). Inside the conduit is an inner electrode (54). A tubular coaxial outer electrode (70) constitutes part of the wall of the conduit. Coupled to the instrument is a radio frequency power generator which delivers high level radio frequency energy in single-shot or repeated bursts to the electrodes (54, 70) while gas is flowing through the conduit (38) so as to create a gas plasma between the electrodes which then emerges from the nozzle (180N) for tissue treatment. A resonant focussing element (480) may be located in the conduit (38) between the electrodes (54, 70) to aid plasma striking. The combination of high peak power (e.g. greater than 750 W) and short treatment pulses (e.g. less than 30 ms) allows rapid surface treatment without significant thermal effects at unwanted depths.

Abstract: A tissue resurfacing system has a handheld surgical instrument with a gas conduit (38) which terminates in an exit nozzle (180N). Inside the conduit is an inner electrode (54). A tubular coaxial outer electrode (70) constitutes part of the wall of the conduit. Coupled to the instrument is a radio frequency power generator which delivers high level radio frequency energy in single-shot or repeated bursts to the electrodes (54,70) while gas is flowing through the conduit (38) so as to create a gas plasma between the electrodes which then emerges from the nozzle (180N) for tissue treatment. A resonant focussing element (480) may be located in the conduit (38) between the electrodes (54,70) to aid plasma striking. The combination of high peak power (e.g. greater than 750 W) and short treatment pulses (e.g. less than 30 ms) allows rapid surface treatment without significant thermal effects at unwanted depths.