1. Division of Pulmonology, University Hospital Zurich, 8091 Zurich, Switzerland
2. Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland
3. IBM Research Europe, 8803 Rüschlikon, Switzerland
4. Department of Mathematics, ETH Zurich, 8092 Zurich, Switzerland
5. Department of Computer Science, ETH Zurich, 8092 Zurich, Switzerland
6. Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland