[Retracted] Edge-Enabled Heart Rate Estimation from Multisensor PPG Signals

Table 1

A research review of artifact removal techniques based on PPG sensors in recent years.

Published works	Activities	PPG sensor wavelength	PPG sensor quantity and deployment area	Artifact types	Algorithm types	Reference sensors
Zhang [17]	HR	PPG (515 nm, green)	1; Wrist	MA	JOSS	Accelerometer
Jarchi and Casson [18]	IHR	PPG (515 nm, green)	1; Wrist	MA	SMA	Accelerometer
Wijshoff et al. [19]	PR,IBI,	PPG (660 nm, red; 900 nm, near infrared)	2; Forehead	BMA + RMA	LMS	Accelerometer + laser diode
Lee et al. [20]	HR	PPG (570 nm, green)	9; Wrist	MA	SVD	PPG
Khan et al. [21]	HR	PPG (515 nm, green)	1-2; Wrist	MA + BA	RLS	Accelerometer
Dao et al. [22]	HR,	PPG (940 nm, infrared)	2; Forehead or finger	MA	VFCDM + SVM	None
Antink et al. [25]	RR interval	PPG (near infrared)	1; Back	MA	xCLIE	ECG, BCG, HFI, and camera
Warren et al. [27]	PR	PPG (660 nm, red; 940 nm, infrared)	4; Forehead	MA	MTM	Accelerometer + PPG (red and infrared)
Antink et al. [43]	HR	PPG (-, green)	1 Forehead	MA	Bayesian	ECG, BCG + webcam
Arunkumar and Bhaskar [44]	HR	PPG (515 nm, green)	2; Wrist	MA	RLS + NLMS + FFT + PV	Accelerometer
Liu et al. [4]	HR	rPPG	1; Face	MA	DFROIT + PCKF	ECG + BCG

Note. MA: motion artifacts; PR: pulse rate; BMA: body motion artifact; RMA: relative motion artifact; SVD: singular value decomposition; JOSS: joint sparse spectrum; VFCDM: variable frequency complex demodulation; SVM: support vector machine; ECG: electrocardiogram; BCG: ballistocardiogram; HFI: high-frequency impedance; xCLIE: multichannel extended continuous local interval estimator; PF: particle filter; ABP: arterial blood pressure; SFM: sensor fusion method; TBC: tree-based classifier; MDC: minimum-distance classifier; MTM: multichannel template matching; TM: threshold method; NLMS: normalized least mean squares; FFT: fast fourier transform; PV: phase vocoder; rPPG: remote photoplethysmography; DFROIT: deep facial ROI tracker; and PCKF: pose constrained Kalman filter.