Respiratory Motion Imaging Using 2.4-GHz Nine-Element-Array Continuous-Wave Radar

A radar system with antenna array and signal processing method are presented for noncontact monitoring of human respiration. We develop a 2.4-GHz nine-element radar system and use it to measure the respiratory rate of a participant lying on a bed. The results show that this system and method can image a respiring body and estimate its instantaneous respiration rate accurately. The accuracy of the proposed system is validated by simultaneously recording the ribcage circumference using a piezoelectric respiratory sensor and the 3-D body shape using a depth camera. The results indicate the potential of this system for long-term respiratory monitoring during sleep periods.