Table 3. Comparison of the results of different FHR extraction methods.

Method	Dataset	Se(%)	PPV(%)	F1(%)
STVD [35]	68 1-minute recordings	90.50	89.4	89.90
EKF [35]	68 1-minute recordings	82.20	80.10	81.10
TVD+TSPCA [35]	68 1-minute recordings	87.70	87.20	87.40
TSPCA [35]	68 1-minute recordings	87.20	86.10	86.70
TSLpca [34]	14 1-minute recordings	94.70	96.00	95.04
	11 5-minute recordings	89.90	88.80	89.30
LMS [34]	14 1-minute recordings	95.80	95.00	95.40
	11 5-minute recordings	89.30	86.50	87.90
RLS [34]	14 1-minute recordings	96.20	95.60	95.90
	11 5-minute recordings	89.70	86.80	88.20
ESNa [34]	14 1-minute recordings	97.20	97.30	97.20
	11 5-minute recordings	91.40	88.90	90.20
TA [36]	75 1-minute recordings	97.40	97.20	97.30
	24 20-minute recordings	85.80	85.00	85.40
EKS [36]	75 1-minute recordings	93.10	92.80	93.00
	24 20-minute recordings	86.80	85.90	86.30
EKS+DE+ANFIS [8]	54 1-minute recordings	94.21	96.05	95.12
	150 1-minute recordings	91.47	92.18	91.82
EKF+DE+ANFIS [8]	54 1-minute recordings	93.03	95.05	94.03
	150 1-minute recordings	88.88	91.80	90.32
SDV+SW [9]	1 5-minute recording	99.53	99.69	99.61
	1 5-minute recording	99.20	99.36	99.28
	1 1-minute 20-second recording	98.31	98.86	98.58
CEEMDAN [13]	5 30-second recordings	99.15	98.27	98.6
	4 30-second recordings	100	100	100
	5 40-second recordings	97.15	95.31	96.2
THR [19]	5 1-minute recordings	95.57	97.99	96.76
	5 5-minute recordings	98.28	98.19	98.24
	2 15-minute recordings	97.91	97.10	97.50
Clustering-based FHR monitoring	11 5-minute recordings	97.50	98.58	98.04
Signals selected by a cardiologist	64 1-minute recordings	97.51	98.63	98.07
Clustering-based FHR monitoring	5 5-minute recordings	98.40	98.86	98.63
Best performing channels	26 1-minute recordings	97.93	99.11	98.52