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US 8,805,480 B2Granted
Tissue detection and ablation apparatus and apparatus and method for actuating a tuner
AssigneeMedical Device Innovations Limited
InventorsChristopher Paul Hancock, John Bishop
Life of this patent
Estimating the term…
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.
Claims16
A tissue classifying apparatus comprising:
- a microwave radiation source which outputs microwave radiation having a single stable frequency in the range of 5 to 60 GHz;
- a cable having a high phase stability under flexure which connects at a first end to the microwave radiation source;
- a probe which is connected to a second end of the cable, which is fitted with a distal end made from a rigid low loss ceramic which distal end penetrates into biological tissue to deliver the microwave radiation from the microwave radiation source to a region of tissue in direct contact with the distal end of the probe and which produces a reflected signal from the microwave radiation reflected back from the region of the tissue in direct contact with the distal end of the probe;
- a mixer which receives the reflected signal and a reference signal which is a portion of the output microwave radiation of the microwave radiation source, and which mixer reduces the frequency of the reflected signal and reference signal, the mixer having
- a first input selectively connected to receive the reflected signal or the reference signal,
- a second input connected to receive a mixing down signal, and
- an output for a mixed down reference signal and a mixed down reflected signal;
- a reflected radiation detector connected to the output of the mixer to receive the mixed down reflected signal and the mixed down reference signal, where the detector detects the magnitude and phase of both the mixed down reflected signal and the mixed down reference signal;
- and
- a tissue classifier which:
- classifies the region of tissue in direct contact with the distal end of the probe into a tissue type or tissue state based on a complex impedance of the region of tissue in direct contact with the distal end of the probe calculated from the magnitude and phase of the mixed down reflected and reference signals detected by the detector, and on a calibration value, obtained by measuring the impedance at the distal end of the probe for a known impedance, to which the calculated complex impedance is referenced, and
- displays the tissue type or tissue state of the region of tissue in direct contact with the distal end of the probe on a display.
9 more elements
A method of classifying tissue comprising the steps of:
- inserting a distal end of a probe into direct contact with a region of tissue to be classified, the distal end being fitted to the probe and being made from a rigid low loss dielectric ceramic,
- directing microwave radiation having a frequency in the range of 5 to 60 GHz from a microwave source, through a cable having a high phase stability under flexure connected to said probe, and into the region of tissue,
- receiving a reflected signal in a mixer, the reflected signal comprising microwave radiation reflected from the region of tissue in direct contact with the distal end of the probe back through the probe,
- receiving a reference signal in the mixer, the reference signal comprising a portion of the microwave radiation from the microwave source,
- outputting a mixing down signal from a voltage-controlled oscillator to the mixer,
- reducing with the mixer the frequency of the reflected signal and the reference signal by mixing the reflected signal and the reference signal with the mixing down signal,
- detecting the magnitude and phase of both the mixed down reflected signal and the mixed down reference signal in a reflected radiation detector,
- calculating a complex impedance of the region of tissue in direct contact with the distal end of the probe from the magnitude and phase of the mixed down reflected signal and the mixed down reference signal,
- classifying the tissue type or tissue state of the region of tissue in direct contact with the distal end of the probe based on the calculated complex impedance, and on a calibration value, obtained by measuring the impedance at the distal end of the probe for a known impedance, to which the calculated complex impedance is referenced, and
- displaying the tissue type or tissue state of the region of tissue in direct contact with the distal end of the probe on a display.
7 more elements
Dependencies are inferred from the claim text.