Abstract: The invention concerns a high frequency surgery apparatus for cutting and/or coagulating biological tissue and methods of operating same. The high frequency surgery apparatus includes at least one high frequency generator which in operation forms a high frequency circuit with the tissue to be treated, with the production of an arc, and at least one measuring and calculating device which is connected for signal transmission to the high frequency circuit and which is adapted in operation to ascertain both a DC voltage in the high frequency circuit and also the amplitudes of at least one even and at least one odd harmonic of a fundamental frequency of the high frequency generator and to form a first tissue parameter representative of the kind of tissue to be treated from the relationship of the sum of the amplitudes of the even and the odd harmonics to the DC voltage and to output a tissue signal dependent on the first tissue parameter for subsequent processing.

Abstract: The invention concerns a high frequency surgery apparatus for cutting and/or coagulating biological tissue and methods of operating same. The high frequency surgery apparatus includes at least one high frequency generator which in operation forms a high frequency circuit with the tissue to be treated, with the production of an arc, and at least one measuring and calculating device which is connected for signal transmission to the high frequency circuit and which is adapted in operation to ascertain both a DC voltage in the high frequency circuit and also the amplitudes of at least one even and at least one odd harmonic of a fundamental frequency of the high frequency generator and to form a first tissue parameter representative of the kind of tissue to be treated from the relationship of the sum of the amplitudes of the even and the odd harmonics to the DC voltage and to output a tissue signal dependent on the first tissue parameter for subsequent processing.