Methods and devices for measuring electrical currents

Abstract

A method of eliminating interfering currents in a measuring system being adapted for simultaneous recording electrophysiological signals and measuring fNMR images, comprises the steps of (a) using an electrode device with a rotational symmetry, (b) using a Sp02-sensor that does not contain any conducting materials, said Sp02-sensor operating with fibre-optic components, (c) using metal wires for grounding infusion solutions, (d) providing ring capacitances for rf shielding on signal lines, (e) providing decoupling resistors for ECG measurements, (f) injecting compensation currents being generated on the basis of detected reference signals, and/or (g) using a current voltage converter being subjected to active interference compensation. Furthermore, methods of measuring and amplifying electrical currents as well as circuits and devices for implementing the above methods are described