abstract |
A cryosurgical instrument comprises a metal cooling tip operable to be cooled by a flow of cryogenic fluid within the tip, at least a boiling region of the tip being coated with a heat-insulating coating. The presence of the heat-insulating coating can promote nucleate boiling of the fluid rather than film boiling. Nucleate boiling within the tip provides a greater cooling efficiency of the tip than film boiling. |