Tissue classifying apparatus

A tissue classifying apparatus comprising:

• a source of microwave radiation having a predetermined frequency;
• a probe that is selectively connectable to receive radiation from the source along either a measurement transmission path or a treatment transmission path, the measurement transmission path being independent of the treatment transmission path, and the probe being arranged to deliver radiation from the source in a forward direction into tissue and to receive reflected radiation from the tissue;
• a detector arranged to receive an input that is switchable between a reference signal that is derived from the forward directed radiation from the source and reflected radiation received from the probe along a reflection transmission path;
• a circulator located between the source, the probe and the detector, the circulator being arranged to isolate forward directed radiation along the measurement transmission path from reflected radiation along the reflection transmission path to prevent the forward directed radiation from travelling along the reflection transmission path;
• and
• a tissue classifier connected to the detector,
• wherein the detector is arranged to detect the magnitude and phase of both the reflected radiation and the reference signal, and the tissue classifier is arranged to classify the tissue on the basis of the magnitude and phase of the signals detected by the detector.