Patent ID: 6511476
Filing Date: 2003-01-28
Classification: A61B

Abstract:
An electrosurgical apparatus for supplying high-frequency power from a high-frequency power supply unit to an instrument placed in association with an organic tissue to dissect or coagulate said organic tissue, said electrosurgical apparatus comprising:an impedance calculating section for calculating an impedance value or said organic tissue; a rate-of-impedance-change calculating section for calculating a rate of impedance change of said organic tissue based on said impedance value calculated by said impedance calculating section; and a control section for controlling a high-frequency output of said high-frequency power supply unit based on a predetermined condition provided by an evaluation of both said impedance value calculated by said impedance calculating section and said rate of impedance change calculated by said rate-of-impedance-change calculating section; wherein said impedance calculating section acquires said impedance value by measuring a voltage and a current in said high-frequency output, and said control section detects a short-circuited state between electrodes based on said impedance value and wherein said control section detects said short-circuited state when an absolute value of a negative rate of impedance change becomes equal to or greater than a first predetermined value or said impedance value becomes equal to or smaller than a second predetermined value.