| 摘要 |
A cryosurgical instrument incorporates a heat transfer zone, which abuts against the portion of the cryosurgical instrument near the input refrigerant entrance, and which receives pure input refrigerant at the coldest temperature for quickly and effectively cooling this portion of the cryosurgical instrument. The cryosurgical instrument includes a shaft portion and a handle portion. The shaft portion includes an outer jacket tube having both an open and closed end. The closed end surrounds the freezing zone for freezing live tissue. A middle tube is disposed within the outer jacket tube. An inner tube is disposed within the middle tube. The inner tube is adapted for routing input cryogenic refrigerant therethrough to the freezing zone. The channel between the inner tube and middle tube forms a cryogenic refrigerant exhaust path for exhausting cryogenic refrigerant from the freezing zone. A heat transfer zone is disposed within the handle portion of the cryosurgical instrument near the entrance of the input refrigerant. The heat transfer zone may take the form of a cooling chamber. The cooling chamber is in fluid communication with the inner tube to receive input cryogenic refrigerant from inlet ports therefrom, and is adapted for circulating input refrigerant within the cooling chamber to induce heat transfer from the walls of the chamber into the refrigerant. The cryosurgical instrument further includes an exhaust chamber disposed within the handle portion adapted for receiving exhaust cryogenic refrigerant from the exhaust path. The exhaust chamber is also adapted for receiving exhaust cryogenic refrigerant from the cooling chamber through outlet ports in the cooling chamber.
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