This paper presents SensiumVitals(®) - an FDA cleared and CE marked wireless wearable vital signs monitoring system, developed for frequent surveillance of in-hospital patients. A number of in-house evaluations with artificial data and healthy volunteers were carried out in different stages to assess the reliability of two crucial vital signs measured by the system - respiration and heart rate. In order to illustrate the potential of the system in hospital, a subset of data collected from acutely-ill patients during a separate clinical trial was also analyzed. In all cases the results revealed satisfactory agreement between the values reported by SensiumVitals(®) and those recorded simultaneously by a clinically-approved bedside monitor. However, further work will be required to improve the reliability of the system under certain clinical conditions; which, although not crucial for our intended population (i.e. patients in general ward), pose interesting challenges for upgrading our technology for future use in these types of patients.