抄録
The objective of the present study was to obtain important information for freezing a target tumor down to a given temperature in cryosurgery using the latest 1.5 mm-dia. cryoprobe, Needle I for CryoHit^<TM> system. To this end, freezing experiments were conducted with a tissue phantom made of 0.9 % NaCl aqueous solution gel. The result suggested that an 8-mm margin at the periphery of the ice ball is needed for -40℃ irrespective of the operating gas pressure. It was also demonstrated that the numerical analysis agreed well with the measurement, which indicates the usefulness of numerical simulation for predicting temperatures.