This video clip (in MPEG format) shows how the temperature changes inside a tumour in a Finite Element (FE) simulation of a cryosurgery. The cryosurgery uses extremely low temperature (so called "cryoprobes") to kill abnormal cells. A pre-operational FE simulation will help doctors to optimize treatment. Computational results are shown every 5 seconds in this movie through the Tecplot, a visual post-treatment software. The tumour is assumed to be a 60mm-diameter circle area with an initial temperature, 37 ^oC, uniformly. Six cryoprobes are placed symmetrically in the tumour. Only one quarter of the tissue is analyzed and shown due to the symmetrical conditions along X and Y axises, respectively. Natural boundary conditions (i.e. the heat flux is zero) are applied at these symmetrical boundaries. For the outline of the tumour, a constant body temperature is maintained (T=37 ^oC). The total simulating time is 1,000 seconds. The first 500 seconds are used for cooling and the second 500 seconds for natural thawing. In the first 500 seconds, the temperature at the cryoprobes is cooled down to - 165 ^oC at about 20 seconds and, then kept at this low temperature until reaching 500 seconds.

Video Clip