Abstract: A calibration method and apparatus for surgical antennas arranged to deliver microwave radiation into biological tissue. An emitting region of the antenna is exposed to a plurality of calibration standards having different complex impedances at the treatment frequency. Calibration standards are created in a short-circuit-terminated waveguide cavity of variable length. In another variation, each calibration standard is a different mixture of liquids. Measurement of the magnitude and phase of signals reflected from the emitting region when exposed to the calibration standard permits calibration of the antenna; Also disclosed is a tissue treatment apparatus having an ablation channel for conveying microwave radiation to a surgical antenna at a high power level, with a separate measurement channel for conveying radiation at a low power level. A surgical antenna having an impedance transformer for matching a coaxial feed structure that terminates in radiating elements with tissue to be treated is also disclosed.

Abstract: The present invention relates to an apparatus for classifying and/or ablating tissue. By directing microwave radiation through a probe (5) into tissue (6) and detecting the amplitude and phase of radiation reflected back through the probe and a reference signal, the tissue type can be classified. An impedance tuner which is actuated by magnetostrictive material (800) is also disclosed.

Abstract: An apparatus and method for ablating tissue is disclosed. The apparatus comprises a source of microwave radiation (1), a probe (5) for directing the microwave radiation into tissue, one or more detectors for detecting the power and phase of the microwave radiation and an impedance adjuster (50) for adjusting impedance so as to minimize the amount of microwave radiation which reflected back through the probe. The detector or detectors use a local oscillator (230) to derive the phase information. A modulator for modulating the microwave radiation to a cutting frequency is also disclosed.

Abstract: A calibration method and apparatus for surgical antennas arranged to deliver microwave radiation into biological tissue. An emitting region of the antenna is exposed to a plurality of calibration standards having different complex impedances at the treatment frequency. Calibration standards are created in a short-circuit-terminated waveguide cavity of variable length. In another variation, each calibration standard is a different mixture of liquids. Measurement of the magnitude and phase of signals reflected from the emitting region when exposed to the calibration standard permits calibration of the antenna; Also disclosed is a tissue treatment apparatus having an ablation channel for conveying microwave radiation to a surgical antenna at a high power level, with a separate measurement channel for conveying radiation at a low power level. A surgical antenna having an impedance transformer for matching a coaxial feed structure that terminates in radiating elements with tissue to be treated is also disclosed.

Abstract: A calibration method and apparatus for surgical antennas which are arranged to deliver microwave radiation (e.g. having a treatment frequency of 500 MHz to 100 GHz) into biological tissue is disclosed. An emitting region of the antenna is exposed to a plurality of calibration standards each having a different complex impedance at the treatment frequency. In one embodiment the calibration standards are created in a short-circuit-terminated waveguide cavity of variable length. In another embodiment, each calibration standard is a different mixture of two or more liquids. Measurement of the magnitude and phase of signals reflected from the emitting region when exposed to the calibration standard can permit calibration of the antenna, e.g. by generating a mapping function based on the measured values and known or reference values for the calibration standards.

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: An assembly is described for repairing torn tendons by reattaching them to a bone, in particular although not exclusively for repairing a torn rotator cuff tendon, which allows for reduction of the gap between the tendon and the humerus by pushing the tendon onto its attachment site. Also described is a method of repairing a torn rotator cuff tendon by pushing it onto its attachment site and suturing through the humeral head.

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: An assembly is described for repairing torn tendons by reattaching them to a bone, in particular although not exclusively for repairing a torn rotator cuff tendon, which allows for reduction of the gap between the tendon and the humerus by pushing the tendon onto its attachment site. Also described is a method of repairing a torn rotator cuff tendon by pushing it onto its attachment site and suturing through the humeral head.

Abstract: A probe and associated apparatus for treating oesophageal tissue with microwave radiation (e.g. radiation having a frequency of 5-60 GHz) are disclosed. The probe comprises a flexible substrate that expands and retracts between an access configuration, e.g. suitable for insertion through an endoscope, and a treatment configuration in which radiating elements, e.g. conducting patches, monopole antennas, slots in a conducting strip or the like, are brought into close proximity with tissue to be treated. The radiating elements are arranged to emit a substantially uniform electromagnetic field with a suitable penetration depth into the tissue. The apparatus can monitor and control the power delivered from the probe into tissue. A method of hollow tube, e.g. oesophageal, pathological treatment and a device for opening and closing the probe are also disclosed.

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: A calibration method and apparatus for surgical antennas which are arranged to deliver microwave radiation (e.g. having a treatment frequency of 500 MHz to 100 GHz) into biological tissue is disclosed. An emitting region of the antenna is exposed to a plurality of calibration standards each having a different complex impedance at the treatment frequency. In one embodiment the calibration standards are created in a short-circuit-terminated waveguide cavity of variable length. In another embodiment, each calibration standard is a different mixture of two or more liquids. Measurement of the magnitude and phase of signals reflected from the emitting region when exposed to the calibration standard can permit calibration of the antenna, e.g. by generating a mapping function based on the measured values and known or reference values for the calibration standards.

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 cauterise tissue e.g. broken blood vessels simultaneously with cutting. The antenna may be integral with the cutting element, e.g. a metallised 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: The present invention relates to an apparatus for classifying and/or ablating tissue. By directing microwave radiation through a probe (5) into tissue (6) and detecting the amplitude and phase of radiation reflected back through the probe and a reference signal, the tissue type can be classified. An impedance tuner which is actuated by magnetostrictive material (800) is also disclosed.