1. Pain Research Group, Pain Center South, University Hospital Odense , Heden 7-9, Indgang 200 , DK – 5000, Odense C , Denmark
2. Institute of Clinical Research, Faculty of Health Sciences, University of Southern Denmark , Odense , Denmark
3. SMI, Department of Health Science and Technology , School of Medicine, Aalborg University , Aalborg , Denmark
4. Clinical Development-Center, Asahi Kasei Pharma Corporation , Tokyo , Japan