Diaphragmatic dysfunction after abdominal surgery can result in extended hospital stay and increased medical costs, because it is related with atelectasis, lung collapse or pneumonia. The mechanism of diaphragm dysfunction is thought to be from not only direct injury to abdominal wall and viscera but inhibitory reflexes of phrenic activity. Thoracic or upper abdominal surgery is suggested as a risk factor of postoperative diaphragm dysfunction, and perioperative analgesic modality is also known to affect diaphragm movements. But there has been no trial to investigate the effect of laparoscopic pelvic surgery such as prostatectomy on diaphragm movement. Moreover, it is not clear if minimally invasive Robot-assisted laparoscopic radical prostatectomy (RALRP) has any influence on respiratory and diaphragm functions.