| abstract |
A cryosurgical instrument includes a cryoprobe operative to form an ice ball in tissue of a patient targeted for cryosurgery upon activation, a sheath disposed over the cryoprobe and at least one measuring device supported by the sheath for measuring a parameter of the tissue of the patient. The instrument includes a processor for predicting formation of the ice ball by the cryoprobe over time and a display for displaying the prediction of ice ball formation. The processor is responsive to an output signal provided by the measuring device and a model of the effective thermal conductivity of the tissue of the patient targeted for surgery. In one embodiment, the measuring device is embedded in the sheath and measures temperature, thermal conductivity, blood perfusion rate and/or thermal diffusivity. The processor may be further responsive to an impedance measurement circuit for verifying the prediction. |