High frequency surgery apparatus and method of operating same

A high frequency surgery apparatus for cutting biological tissue, comprising:

• a high frequency generator which in operation forms a high frequency circuit with the biological tissue with formation of an arc, and which produces an output voltage or an output current,
• at least one measuring and calculating device which is connected for signal transmission to the high frequency circuit and which is configured to determine both a DC voltage in the high frequency circuit and one of (a) the output current in the high frequency circuit and (b) an amplitude of at least one harmonic of a fundamental frequency of the high frequency generator;
• wherein said measuring and calculating device being also configured to form a speed parameter representative of a cutting speed from one of:
• (a) a quotient of the DC voltage and the amplitude of the harmonic and (b) a quotient of the DC voltage and the output current;
• and
• said measuring and calculating device being also configured to output a speed signal dependent on the speed parameter for subsequent processing.

A high frequency surgery method, comprising:

• cutting and/or coagulating biological tissue with a high frequency circuit formed between at least one high frequency generator and the biological tissue, with the formation of an arc,
• determining both a DC voltage in the high frequency circuit and amplitudes of at least one even and at least one odd harmonic of a fundamental frequency of the high frequency generator,
• determining a first tissue parameter representative of the biological tissue from a quotient of the sum of the amplitudes of the at least one even and the at least one odd harmonics to the DC voltage;
• and
• outputting a tissue signal dependent on the first tissue parameter for subsequent processing.

A high frequency surgery method, comprising:

• cutting and/or coagulating biological tissue with a high frequency circuit formed between at least one high frequency generator and the biological tissue, with the formation of an arc,
• determining both a DC voltage in the high frequency circuit and also an effective value of an output current in the high frequency circuit or the amplitude of at least one harmonic of a fundamental frequency of the high frequency generator,
• determining a speed parameter representative of a cutting speed from the quotient of the DC voltage and the amplitude of the at least one harmonic or the quotient of the DC voltage and the output current, and
• outputting a speed signal dependent on the speed parameter for subsequent processing.