1 1 Department of Thoracic Surgery and Tumors, Oncology Centre, Prof. Łukaszczyk Memorial Hospital in Bydgoszcz, Bydgoszcz, Poland ; 2 Department of Thoracic Surgery and Tumors, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland ; 3 Department of Cardiac Surgery, Dr Antoni Jurasz Memorial University Hospital in Bydgoszcz, Bydgoszcz, Poland ; 4 Division of Ergonomics and Physical Effort Department of Hygiene, Epidemiology and Ergonomics, Collegium Medicum UMK, Bydgoszcz, Poland.