1. Neuroelectronics, Munich School of Bioengineering, Department of Electrical and Computer Engineering, Technical University of Munich, Boltzmannstr. 11, 85748 Garching, Germany
2. Medical & Health Informatics Laboratories, NTT Research Incorporated, 1950 University Avenue Suite 600, East Palo Alto, California 94303, United States
3. Chair of Medical Materials and Implants, Department of Mechanical Engineering, Technical University of Munich, Boltzmannstr. 15, 85748 Garching, Germany
4. Institute of Biological Information Processing, Bioelectronics (IBI-3), Forschungszentrum Jülich, 52425 Jülich, Germany