A Feasibility Study for Life Signs Monitoring via a Continuous-Wave Radar

Abstract

We present a feasibility study for life signs detection using a continuous-wave radar working in the band around 4 GHz. The data-processing is carried out by using two different data processing approaches, which are compared about the possibility to characterize the frequency behaviour of the breathing and heartbeat activity. The two approaches are used with the main aim to show the possibility of monitoring the vital signs activity in an accurate and reliable way.

Cardiorespiratory Frequency Monitoring Using the Principal Component Analysis Technique on UWB Radar Signal

“…The first radar system applied for the monitoring of respiratory activity was the Doppler radar, which uses a continuous wave signal in the microwave range [7][8][9]. The UWB radar is a valuable alternative due to its better performances compared with the Doppler one.…”

Wireless Sensing for the Respiratory Activity of Human Beings: Measurements and Wide-band Numerical Analysis

“…As a consequence, the possibility to monitor the respiratory activity with a noncontact method has been an object of numerous recent investigations [13][14][15][16][17][18][19]. Laser Doppler vibrometry has demonstrated to be valid and reliable during in-vivo tests [13][14][15], whereas a second alternative approach is electromagnetic (EM) sensing [16][17][18][19][20][21][22][23]. The first EM approaches proposed [16,17] were not adopted because of the bulky, complex, and rather expensive hardware.…”

“…Recent examples of pulsed UWB radar [18][19][20] were adopted to precisely measure respiration and heartbeat. Echo signals using mono [22] and double antenna [23] CW systems are measured at different working frequencies aiming to detect vital signs. These recent works are of extreme interest in view of a future transfer of this approach to wireless, market-ready monitoring systems.…”

“…The great interest on the EM sensing of the respiratory activity is due to the wireless feature of the technique, realized with small antennas illuminating from a distance. Moreover, it is important to underline that, in order to operate, the antenna does not need to be accurately pointed toward a specific part of the subject's body (as for laser-based methods), but it can generally illuminate the region where the monitored subject is positioned [22][23][24][25]. Finally, it is worth noting that EM sensing makes it possible to measure through clothes or fabric (bed sheets, blankets, clothes, etc.)…”

Comparison of Bioradiolocation and Respiratory Plethysmography Signals in Time and Frequency Domains on the Base of Cross-Correlation and Spectral Analysis

“…Effective noncontact monitoring of breathing pattern is an important aspect of functional diagnostics and vital signs monitoring [1]. In analysis of respiratory movements character, thoracic and abdominal components are usually taken into consideration.…”