Bio-radar performance evaluation for different antenna designs

Abstract

Cardiopulmonary monitoring without any physical contact with the human body has several applications, such as health monitoring of bedridden patients, monitoring sleeping, or even for rescuing people from collapsed buildings. The Bio-Radar system can accurately measure vital signals by using the principle of the Doppler effect, which relates the properties of the received signal to the distance change between the radar antennas and the person's chest wall. In this paper, a mathematical model of the Bio-Radar is presented. The algorithm used for extracting breathing rate is explained, and an analysis of the influence of the radiation pattern of the antenna on the quality of the received signal is presented. Moreover, we show that an antenna with a narrow beam leads to a better signal-to-noise ratio (SNR). The full performance of the developed prototype was also evaluated by using a certified measuring system to monitor vital signals simultaneously with the Bio-Radar. The signals extracted using both acquisition methods are presented, and a comparison is made in order to prove the accuracy of the prototype.