1. Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland
2. Department of Endocrinology, Diabetology, and Clinical Nutrition, University Hospital Zürich (USZ) and University of Zürich (UZH), CH-8091 Zürich, Switzerland
3. Institute for Breath Research, Universität Innsbruck, Innsbruck A-6020, Austria
4. Human-centered Sensor Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland