Method and measurement apparatus for determining the transition impedance between two parts of a subdivided neutral electrode
First Claim
1. Measurement apparatus for determining the transition impedance between two electrode parts of a subdivided neutral electrode for employment in high-frequency surgery, comprising a resonant circuit within which said two electrode parts are connected in parallel;
- a current-supply device adapted to impress a measurement alternating voltage into the resonant circuit;
a phase-measuring device; and
a control means adapted to determine the phase of the current and of the voltage by means of the phase-measuring device in order that the frequency of the current-supply device is controlled by the control means in such a way that current and voltage are in phase.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and a measurement apparatus are provided for determining the transition impedance between two electrode parts of a subdivided neutral electrode used in high-frequency surgery. These make it possible for the purely capacitive component of the transition impedance to be measured. For this purpose a resonant-frequency shift is measured, which occurs when a basic resonant circuit is expanded to an expanded resonant circuit by incorporating the two electrode parts into it in parallel. In particular, in order to determine the basic resonant frequency of the basic resonant circuit and/or the sample resonant frequency of the expanded resonant circuit, the phase shift between current and voltage is measured and the frequency is adjusted until current and voltage are in phase.
147 Citations
7 Claims
-
1. Measurement apparatus for determining the transition impedance between two electrode parts of a subdivided neutral electrode for employment in high-frequency surgery, comprising a resonant circuit within which said two electrode parts are connected in parallel;
-
a current-supply device adapted to impress a measurement alternating voltage into the resonant circuit; a phase-measuring device; and a control means adapted to determine the phase of the current and of the voltage by means of the phase-measuring device in order that the frequency of the current-supply device is controlled by the control means in such a way that current and voltage are in phase. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
Specification