Rationale: Monitoring patients' vital signs is done to detect clinical deterioration. For this, the MEWS, a scoring list comprising seven vital signs measured by nursing staff, is used. Although the MEWS provides relevant data on patients' health status, the interval measurements may not capture early deterioration of vital signs, especially during the night. As a result, unsafe situations may occur such as periods of low oxygen saturation and cardiac arrhythmias, which are known to complicate postoperative course. Besides, this way of measuring vital signs may be stressful for patients and disturbs patients' sleep. New technology such as ViSi Mobile and HealthPatch allows for remote continuous monitoring of vital signs using wearable devices transmitting relevant data to nurses and clinicians. With this, the investigators think that clinical deterioration may be detected in an early phase and reduce nurse work load and patient distress.