Motion Cancellation Technique of Vital Signal Detectors Based on Continuous-Wave Radar Technology

Figures

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  Figure 1. Block diagram of a CW radar system for vital signal detection.

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  Figure 2. Block diagram of multi antenna radar to reduce body motion artifacts and common noise (reproduced with permission from the corresponding author, Differential phase Doppler radar with collocated multiple receivers for noncontact vital signal detection, published by IEEE, 2019) [12].

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  Figure 3. Dual-radar structure for reducing random body movements to obtain accurate vital signs. (a) Front-and-rear radar placement; (b) configuration considering the asymmetrical movements of human organs [17].

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  Figure 4. Multi-view beamforming radar system configuration: (a) block diagram, (b) top view of the simulation setup, and (c) 2D side view of the simulation setup (reproduced with permission from the author; Multiview beamforming radar for random body motion cancellation, published by IEEE, 2024) [20].

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  Figure 5. Block diagram of the SIL oscillator radar system with a single-chip single-antenna (reproduced with permission from the author; A single-chip single-antenna radar for remote vital sign monitoring, published by IEEE, 2023) [22].

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  Figure 6. (a) Block diagram of the SIL and (b) SMIL radar system with multiple antennas (reproduced with permission from the author; Single self-injection-locked radar with two antennas for monitoring vital signs with large body movement cancellation, published by IEEE, 2017. A self- and mutually injection-locked radar system for monitoring vital signs in real time with random body movement cancellation, published by IEEE, 2016) [22,23].

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  Figure 7. Illustration of the detection setup of the motion modulation effect (reproduced with permission from the corresponding author; Respiration rate measurement under 1-D body motion using single continuous-wave Doppler radar vital sign detection system, published by IEEE, 2016) [31].

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  Figure 8. Schematic of adaptive noise cancellation [33].

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  Figure 9. Constellation of simulated signal and four points for DC offset demodulation: (0, 0), (0, 0.5), (0, 2), (2, 0) [35].

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  Figure 10. Tracking-aided range-spread (TA-RS) respiration detection method (reproduced with permission from the corresponding author; Tracking-aided respiration detection using radar during large-scale body movements, published by IEEE, 2023) [36].

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  Figure 11. (a) Simulated radar sensor signal consisting of a respiration component, heartbeat, and motion artifact. The motion artifact component occupies the segment between t = 30–50 s. (b) High-pass filtered sensor output and intrinsic mode functions (the IMFs) within EMD (reproduced by the authors, Cancellation of unwanted Doppler radar sensor motion using empirical mode decomposition; published by IEEE, 2013) [40].

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  Figure 12. Results of ICEEMDAN decomposition. The left and right sides display the time and frequency domains, respectively (reproduced with permission from the author; A single-chip single-antenna radar for remote vital sign monitoring, published by IEEE, 2023) [43].