A novel respiratory signal detection system capable of simultaneously tracking the position of the subject and detecting his or her respiratory signal is described. The monitoring system consists of depth camera with ultra wide band radar device. Both sensors are connected through a mini computer, which performs data acquisition and storage. In this paper, we propose a method to locate the position of the subject where he or she is lying in the bed covered with blanket. Mask R-CNN is used to help segment upper-body's silhouette and give out the center point distance. The distance between the camera and the subject is then converted into a range bin of the radar and the breath-like signal is extracted from that range- bin. Additional contribution of this paper is that we developed a classifier to classify the whether the extracted signal in the selected range bin is indeed a breathing signal or not.