The purpose of this paper is to introduce an accurate algorithm to detect respiration rate and heart beat using an Ultra-Wideband (UWB) signal. One important issue to consider for obtaining precise results is the right selection of measurement parameters in UWB system. In this work the impact of these parameters in detecting respiration rate and heart beat are studied and the best values are suggested. The experiments are done using a UWB transceiver with 3.2 GHz of bandwidth in a busy environment without any wave absorbent. The results of the experiments prove an accuracy of 98 % and 90% for detecting of respiration rate and heart beats, respectively. The robustness of the algorithm to environmental noise due to scattering effect is also studied by performing different experiments in two situations.