The passive electrical properties of human tissue are of increasing diagnostic relevance in medicine. Usually, they are measured by electrodes attached to the skin. Unfortunately, electrode measurements suffer from different disadvantages.
A new approach for measuring the passive electrical properties of tissue is the inductive measurement by using coils. Here, an excitation coil generates an eddy current in the tissue, whose secondary magnetic field is measured by a measurement coil (see Fig. 1). The measurement allows to determine the conductivity of the tissue. Hence, the monitoring of organ functions (eg. heart, lung) is possible. Further, the measurement of the impedance spectrums allows to determine pathological change of the tissue. A possible application of this would be graft rejection diagnosis in transplantation medicine.