SSB transceiver for vital sign detection

An integrated remote wireless sensor to measure respiration and heart rate without any contact is presented. The low-power wireless sensor system uses RF transceiver with embedded DSP algorithm to monitor cardiac and respiratory activities. The prototype system is implemented using a quadrature Low-IF Bluetooth transceiver at 2.4 GHz with a 30 KHz single-side band reference tone. The low-IF signal is digitized at 100 KHz and the embedded DSP algorithm estimates the Doppler phase shift, while reducing the system noise, LO phase noise, 1/f noise, DC offset, and minimizes the clutter, multi-path and echo signals. A new Pattern Search in Noise Subspace (PSNS) algorithm is used to estimate the sub-HZ phase shift due to heart and respiratory movement. The prototype system is tested in the lab with multiple individuals at 5-20 ft distance with less than 5% error.