1. Institute of Optical Sensor Systems,German Aerospace Center (DLR),Berlin,Germany
2. Research Institute for Pulmonary Rehabilitation,Schoen Klinik Berchtesgadener Land,Schoenau am Koenigssee,Germany
3. Fraunhofer ITEM, German Center for Lung Research (BREATH, DZL), Clinical Methods Development Group,Hannover,Germany
4. IHP—Leibniz-Institut für Innovative Mikroelektronik,Frankfurt (Oder),Germany