1. Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Germany
2. Fraunhofer Institute Mikroelectronic, Circuits and Systems, Duisburg, Germany
3. Dep. of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Germany
4. Dr. Osypka GmbH, Medizintechnik, Rheinfelden, Germany