Abstract: An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave frequency EM energy from a coaxial feed cable through an instrument tip into tissue. The instrument tip comprises a dielectric body separating first and second conductive elements, which act as active and return electrodes to convey the RF EM radiation by conduction, and as an antenna to radiate the microwave EM radiation. The instrument also has a fluid feed incorporated into its tip, e.g. in an additional dielectric element mounted on the underside of the tip, for delivering fluid. The delivered fluid may be a gas plasma to assist treatment or a liquid to plump up a tissue region before treatment. The instrument may fit in an endoscope.

Abstract: An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave frequency EM energy from a coaxial feed cable through an instrument tip into tissue. The instrument tip comprises a dielectric body separating first and second conductive elements, which act as active and return electrodes to convey the RF EM radiation by conduction, and as an antenna to radiate the microwave EM radiation. The instrument also has a fluid feed incorporated into its tip, e.g. in an additional dielectric element mounted on the underside of the tip, for delivering fluid. The delivered fluid may be a gas plasma to assist treatment or a liquid to plump up a tissue region before treatment. The instrument may fit in an endoscope.

Abstract: An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave frequency EM energy from a coaxial feed cable through an instrument tip into tissue. The instrument tip comprises a dielectric body separating first and second conductive elements, which act as active and return electrodes to convey the RF EM radiation by conduction, and as an antenna to radiate the microwave EM radiation. The instrument also has a fluid feed incorporated into its tip, e.g. in an additional dielectric element mounted on the underside of the tip, for delivering fluid. The delivered fluid may be a gas plasma to assist treatment or a liquid to plump up a tissue region before treatment. The instrument may fit in an endoscope.

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 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: An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave frequency EM energy from a coaxial feed cable through an instrument tip into tissue. The instrument tip comprises a dielectric body separating first and second conductive elements, which act as active and return electrodes to convey the RF EM radiation by conduction, and as an antenna to radiate the microwave EM radiation. The instrument also has a fluid feed incorporated into its tip, e.g. in an additional dielectric element mounted on the underside of the tip, for delivering fluid. The delivered fluid may be a gas plasma to assist treatment or a liquid to plump up a tissue region before treatment. The instrument may fit in an endoscope.

Abstract: Apparatus for detecting a discontinuity within a non-biological element located within a biological structure, the apparatus comprising: a microwave energy source; a first antenna coupled to the microwave energy source and arranged to transmit the microwave energy into the biological structure; a second antenna arranged to receive at least a portion of the transmitted microwave energy; an antenna carrier arranged to have the first and second antenna affixed thereon and including means for moving the first and second antenna with respect to the biological structure; and a signal processing unit coupled to the second antenna arranged to determine the phase and/or magnitude response of the received microwave energy as a function of the position of the antennas with respect to the biological structure and provide an indication of the location of the discontinuity within the non-biological element according to the phase and/or magnitude response.

Abstract: Tissue classifying apparatus in which forward microwave radiation (e.g. having a frequency 500 MHz to 60 GHz) is supplied from a source (108) along a first transmission path to a probe (116) which delivers it into tissue to be classified. The probe (116) receives reflected radiation from the tissue. The reflected radiation is delivered to a detector (178) along a second transmission path via a circulator (198) which isolates the forward radiation from the second transmission path. The detector has a input which is switchable between the reflected radiation from the second transmission path and a reference signal derived from the forward radiation, wherein detected magnitude and phase information of the reflected radiation to classify the tissue can be compensated for drift in magnitude and phase of the forward radiation by comparison with detected magnitude and phase information of the reference signal.

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: Apparatus for detecting a discontinuity within a non-biological element located within a biological structure, the apparatus comprising: a microwave energy source; a first antenna coupled to the microwave energy source and arranged to transmit the microwave energy into the biological structure; a second antenna arranged to receive at least a portion of the transmitted microwave energy; an antenna carrier arranged to have the first and second antenna affixed thereon and including means for moving the first and second antenna with respect to the biological structure; and a signal processing unit coupled to the second antenna arranged to determine the phase and/or magnitude response of the received microwave energy as a function of the position of the antennas with respect to the biological structure and provide an indication of the location of the discontinuity within the non-biological element according to the phase and/or magnitude response.