Table 1.

Features retained from the LASSO technique for each group comparison.

Time domain	0/1	0/2	1/2	0/1/2	Entropies	0/1	0/2	1/2	0/1/2
Mean RR					ApEn	x		x	x
Std RR					SampEn
Mean HR					MSE1
Std HR	x				MSE2
RMDDS					MSE3	x
NN50					MSE4				x
pNN50	x			x	MSE5	x
HRV Tri Ind	x				MSE6
TINN					MSE7		x		x
Frequency domain	0/1	0/2	1/2	0/1/2	MSE8	x
VLF Peak					MSE9
VLF Power (ms${}^2$)	x			x	MSE10	x		x
VLF Power (%)					MSE11	x	x		x
LF Peak	x		x		MSE12	x		x
LF Power (ms${}^2$)					MSE13	x		x
LF Power (%)	x	x	x	x	MSE14
LF Power (n.u.)					MSE15		x	x	x
HF Peak	x	x		x	MSE16	x		x
HF Power (ms${}^2$)	x			x	MSE17	x	x	x	x
HF Power (%)					MSE18	x	x		x
HF Power (n.u.)					MSE19	x		x
LF/HF Power					MSE20				x