Table 3.

Respiration rate and heartbeat rate monitoring using Wi-Fi CSI signals.

Ref. year	Extraction tool	Pre-processing	Detection algorithm	Multi-person	Real-time	Performance summary
[48] 2015	Linux 802.11n CSI Tool	Noise Reduction Signal Transform	Hybrid	No	No	Respiration Rate Error: $<1.1$ bpm (1 person), $<1.2$ bpm (2 persons); Heart Rate Error: $<5$ bpm (1 person)
[12] 2018	Linux 802.11n CSI Tool	Signal Transform Signal Extraction	Modeling-based	No	No	Accuracy: respiration rate 94% heart rate about 82%
[52] 2018	Linux 802.11n CSI Tool	Noise Reduction	Modeling-based	No	No	Accuracy: $80\text{\%}<0.5$ bpm for breath rate, $90\text{\%}<4$ bpm for heart rate
[31] 2020	Linux 802.11n CSI Tool	Signal Transform	Modeling-based	No	No	Median error of 0.25 breaths per minute (bpm) for respiration rate, and 1.19 bpm for heart rate
[35] 2016	Linux 802.11n CSI Tool	Noise Reduction	Modeling-based	No	N/A	Average estimation error under: 0.6 bpm (respiration rate), 6 bpm (heart rate)
[32] 2017	Linux 802.11n CSI Tool	Noise Reduction Signal Transform	Modeling-based	No	Yes	Estimation error: $<0.85$ bpm (respiration rate), $<10$ bpm (heart rate)