This chapter proposes a concurrent dual band non-invasive vital sign– monitoring sensor system. The proposed system is devised on the popular Doppler shift theory and simultaneous operation over two frequency bands, namely, the 2.44 GHz and 5.25 GHz bands. The baseband signal after the mixer stage is generally proportional to chest disarticulation and thus contains information about movement due to heartbeat and respiration. Using this information, the existence of a human life can be ascertained. Based on this notion, a non-invasive heart and respiration monitor is developed. There are various technical obstructions in designing an Non-invasiveVSD (NIVSD) system, such as the influence of clutter noise and phase noise, the harmonics, DC offset, and null point problems. Various academicians and researchers had suggested many techniques to overcome the challenges whereby a stable and reliable detection has been achieved.