High frequency surgical apparatus and method of its operation

摘要

The invention provides a radiofrequency surgical apparatus comprising a high frequency generator having at least one active electrode output and at least one neutral electrode output to which a part neutral electrode of a neutral electrode pair can be connected, with individual electrodes of the neutral electrode pair being connected to an auxiliary voltage with a significantly lower frequency than the high frequency. A monitoring circuit produces from the auxiliary voltage and the auxiliary current flowing between the part neutral electrodes an impedance signal representative for the impedance between the two part neutral electrodes and transmits a high frequency generator blocking signal and/or an alarm signal on exceeding a first fixed upper alarm limit and/or a lower second upper alarm limit for the impedance signal which can be matched to the actual value of the impedance signal. The adaptation of the second alarm limit is effected by pressing a SET key.