A Comparison of ECG and FMCW Radar Heart Beat Measurements Based on an Envelope Analysis

Non-contact monitoring of vital signs is growing for the last few years. One of the advantages is that the patient will not be affected by an attached sensors. The white coat hypertension is one further reason. The latter can lead to higher heart frequency by a consultation as when the patient measures it at home. Non-contact vital signs monitoring at the patient’s home can reduce this affect which leads to better diagnoses. In this publication, a new signal processing method for heart beat extraction out of radar measurements based on a dedicated vital sign FMCW radar is shown. The results will be compared with an ECG (GE Healthcare CARESCAPE Monitor B650). The pronounced radar system hardware consist of three separated modules: a 2 TX x 4RX MIMO radar front-end, a filtering-amplification module and a data acquisition module for the data transfer. All parts are developed in the laboratory of applied radar- and optical systems (LaROS) at the Trier University of Applied Sciences. The presented signal processing is optimized for the presented radar topology and the frequency range of the 24 GHz ISM band and is based onto a signal envelope analysis.