1. Medical Simulation Training Center, Research Institute, Medical University of Plovdiv, 4000 Plovdiv, Bulgaria
2. Department of Gastroenterology, Pulmed University Hospital, 4000 Plovdiv, Bulgaria
3. Department of Clinical Toxicology, St. George University Hospital, 4000 Plovdiv, Bulgaria
4. Second Department of Internal Medicine Therapy, Medical Faculty, Trakia University, 6000 Stara Zagora, Bulgaria
5. Department of Surgery, Pulmed University Hospital, 4000 Plovdiv, Bulgaria